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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuing application, under 35 U.S.C. § 120, of copending international application No. PCT/EP2004/002883, filed Mar. 19, 2004, which designated the United States; this application also claims the priority, under 35 U.S.C. § 119, of German patent application No. 103 12 269.9, filed Mar. 19, 2003; the prior applications are herewith incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The invention relates to a magneto-mechanical locking device for the purpose of locking a door or a window. The magneto-mechanical locking device can move with respect to a stationary frame and contains a locking element disposed on the stationary frame and made from a magnetizable material, and a permanent magnet accommodated on the door and can be rotated from a first release position to a second latching position, in which the locking element is attracted by magnetic force effect of the permanent magnet for latching the door.
[0004] Doors and windows of buildings, vehicles, items of furniture, safes, etc. are locked in a known manner by mechanically actuated locks, for example by cylinder locks, transverse bolt locks or the like.
[0005] There is the problem here that the mechanical locking devices used have a large number of moving parts which interact with one another in order to reliably latch the associated door, the complexity of the mechanical locking devices being greater the higher the requirements placed on the forced entry-inhibiting action of the door or window.
[0006] Owing to the large number of moving mechanical parts which are used in locking devices having a high forced entry-inhibiting action, there is the problem, in particular in the case of greater temperature fluctuations, that the shape of the door or window changes and the interengaging mechanical parts no longer interact with a precise fit for latching purposes.
[0007] It is therefore often necessary to take care, for example in winter, that doors do not become stuck and can only be closed or opened with a considerable amount of effort.
SUMMARY OF THE INVENTION
[0008] It is accordingly an object of the invention to provide a magneto-mechanical locking device that overcomes the above-mentioned disadvantages of the prior art devices of this general type, which has a small number of parts to be produced and which always ensures reliable operation even in the case of great temperature fluctuations.
[0009] In accordance with the invention, a magneto-mechanical locking device for the purpose of locking a door, which can move with respect to a stationary frame, for example an automobile door, a building door, a safe door or else a window, contains a locking element, which is disposed in the frame and is made from a magnetizable material, for example from magnetizable steel or iron, and interacts with a permanent magnet fixed to the door. In this case, the permanent magnet is, according to the invention, accommodated on the door or on the window such that it can be rotated, and can preferably be rotated mechanically by hand from a first, release position, in which substantially no magnetic force effect is exerted on the locking element, to a second, latching position, in which the locking element on the stationary frame is attracted by the magnetic forces exerted by the permanent magnet and latches the door or window in its closed position.
[0010] For reasons of simplicity, the description of the invention below refers to a door, although the described advantages and embodiments also apply to windows in a corresponding manner. The invention provides the advantage that, owing to the remote action of the magnetic forces, there is compensation even for greater fluctuations in the distance between the frame-side locking element and the magnet, such as are produced, for example, by temperature fluctuations depending on the time of year.
[0011] A further advantage of the apparatus according to the invention relates to the fact that it operates virtually without wear and, in comparison to the mechanical locking devices, only has a very small number of moving parts. As a result, in particular when manufacturing the magneto-mechanical locking device according to the invention, considerable costs can be saved, since the tolerances of the individual parts can be selected to be greater than those for mechanical locking devices having a comparable standard of security.
[0012] In accordance with one preferred embodiment of the invention, which allows for particularly reliable latching of a door or window, projections, which engage, in the latching position, in associated receptacles of the door and, as a result, produce an interlocking connection activated by the magnetic forces, are formed on the locking element. The projections are preferably formed by pins or tabs, which engage in associated holes or grooves in the door, the holes or grooves preferably extending over the entire length of the locking element.
[0013] In this case, the locking element is preferably formed by a striking plate, which can move relative to the stationary frame of the door or window and, in the second, latching position, enters into an interlocking connection with the permanent magnet or with the associated part of the door, which connection latches the door or window.
[0014] In accordance with a further embodiment of the invention, the locking element may be formed by a locking bolt, which is accommodated linearly in a guide hole formed in the frame such that it can move. This results in a cost-effective configuration of the locking device according to the invention that is particularly simple in mechanical terms.
[0015] In accordance with a further refinement of the concept on which the invention is based, further permanent magnets, which produce a magnetic force which is less than that of the permanent magnet on the door, are disposed on that side of the locking element which is remote from the door. The size and the magnetic field of the further permanent magnets are in this case selected such that, in the latching position, the locking element is attracted by the permanent magnet of the door and latches the door, but, in the release position, on the other hand, is forced away from the door by the further permanent magnets and releases the latching of the door. Owing to this refinement of the invention, which is advantageously subject to virtually no wear, a further reduction in the mechanical parts used results.
[0016] However, it is likewise possible in the same way for a spring-elastic device, for example a spiral tension spring, to be used instead of the further permanent magnet, the spring-elastic device forcing the locking element away from the door in the same way in the release position, in which no or virtually no magnetic field is present in the region of the locking element, and, as a result, canceling the latching action. In the latching position, the locking element is then attracted towards the door, counter to the action of the spring-elastic device, owing to the considerably greater magnetic forces of the permanent magnet until it bears against the door edge or the magnet.
[0017] In the preferred embodiment of the invention, the permanent magnet is formed by a cylindrical or rod-shaped magnet, which is preferably polarized in the transverse direction, i.e. in the direction perpendicular to the longitudinal axis of the magnet, and is accommodated in a housing, which is substantially closed in the circumferential direction and is made from a magnetizable material, for example iron. The hole formed for this purpose in the housing has a slightly larger diameter than the magnet and preferably at the same time is used for mounting the magnet.
[0018] The magnet may be formed from a known permanent magnet material, for example from ferrite, or else, in a particularly expedient embodiment, from cobalt samarium or another rare earth material, which produces a very high magnetic force.
[0019] The use of a rod-shaped or cylindrical permanent magnet, which is accommodated in a closed housing such that it can rotate, results in the advantage that unlatching and latching of the door only requires a very low actuation force or, to be precise, a very small torque, since, with the exception of the frictional forces when moving the locking element in the direction towards the magnet and the frictional forces, which are produced by the mounting of the rod-shaped permanent magnet, no mechanical frictional forces are produced whatsoever. As a result, it is likewise not necessary to oil the entire mechanism or to make the mechanism smooth in another complex way by corresponding selection of the materials, since the forces for latching the door or the window are transferred by the remote action of the magnetic forces alone.
[0020] Furthermore, provision may advantageously by made for the latching effect to be produced by the fact that the locking element engages directly in a cutout formed in the housing of the permanent magnet in order to obtain an interlocking connection, which is protected against manipulations from the outside, for the purpose of latching the door. This results in a particularly cost-effective refinement of the invention, since the permanent magnet, together with the housing, can be used as one unit in a correspondingly shaped cutout in the door, without additional components being required.
[0021] In this embodiment of the invention, the magnet can advantageously also be fixed from the inside of the door with the aid of screw bolts, which are passed through longitudinal holes formed in the housing of the magnet and can be screwed into corresponding thread holes in a door fitting in a known manner, the door fitting being disposed on the outside of the door for the purpose of protecting the locking mechanism. As a result, a locking device can be achieved with very little complexity, which can be produced in a very cost-effective manner owing to the small number of mechanical components and can be retrofitted in existing doors using simple measures with effective protection against the door being broken open.
[0022] In accordance with a further embodiment of the invention, the alignment of the permanent magnet in the housing is preferably such that the longitudinal axis of the permanent magnet extends substantially perpendicular to the plane of the door. In other words, the permanent magnet extends through the door leaf in the same manner as a conventional locking cylinder in the region, in which the door lock is generally disposed. The permanent magnet in this case preferably has a length, which is slightly less than the thickness of the door leaf, it being possible, however, for provision likewise to be made for the length of the magnet to be selected to be slightly larger, and the housing of the magnet to be drawn out of the door leaf, in particular towards the inside of the door, in order to obtain increased magnetic force, with which the locking element is attracted so as to latch the door.
[0023] The permanent magnet is preferably rotated back and forth between the release position and the latching position by an actuating element, which can rotate mechanically, on the outside of the door, it being possible for the actuating element, in the simplest refinement of the invention, to be provided with a knob, which is preferably covered by a protective fitting fitted on the outside of the door. This results in the advantage that the locking device for the purpose of latching the door can be configured to be completely independent of the function of the protective fitting, with the result that the encoding for the purpose of opening the door is determined by the protective fitting alone, while latching of the door takes place in the manner described above with the aid of the magnet.
[0024] In the preferred embodiment of the invention, the magnet, which has been inserted in the door in the manner described above, is driven, however, with the aid of a protective fitting, for example a viewing fitting or else a core protective rosette, as is produced by the applicant, and is described, for example, in the German utility model DE 93 17 012 U1. In this case, the permanent magnet is coupled to the outer part, which can rotate, of the protective fitting via a known polygonal shaft, for example a square shaft, the center of rotation of the protective fitting being disposed on the extension of the central mid-axis of the permanent magnet. The magneto-mechanical locking device according to the invention, which is actuated in this manner with the aid of a preferably circular protective fitting, which can rotate, (also referred to below as a protective rosette) offers, along with a very simple configuration, excellent protection against the door being broken open and is also characterized by a very long life, since the locking mechanism as such is subject to virtually no wear.
[0025] In the same manner, there is the possibility of rotating the cylindrical permanent magnet with the aid of a displaceable protective fitting, as is manufactured, for example, by the Applicant and is described in the European patent EP 0 367 000 B1. For this purpose, the displaceable part of the protective fitting, for example on its inside, may be provided with a linear toothed section in the form of a toothed rack, which is in engagement with a pinion, which is accommodated on a shaft, which may be fixed to the permanent magnet in the region of its center of rotation.
[0026] In this embodiment of the invention too, at the same time as the insertion of the key, which has specially been provided with pins, in the protective fitting and displacement of the same owing to the toothed engagement, the permanent magnet is rotated from the latching position to the release position and thus the locking device according to the invention is unlatched, since, in the release position, the magnetic field, which acts on the locking element, within the housing of the magnet is changed such that the region outside the permanent magnet has virtually no field, with the result that no force is exerted on the locking element any more.
[0027] In order to latch the door, the protective fitting is displaced back to the initial position, and the key is removed from the protective fitting, in which case, owing to the interaction of the pinion and the toothed rack and the movement of the displaceable part of the protective fitting, the magnet is rotated through approximately 90° back to the latching position, in which the striking plate is attracted by the magnetic field caused by the permanent magnet with a very high force in the direction of the magnet, and latches into the corresponding projections there in order to latch the door.
[0028] However, in the same way it is likewise possible for the permanent magnet to be rotated with the aid of a conventional locking cylinder or profile cylinder, which may extend, for example, into the interior of the permanent magnet and is connected to the permanent magnet such that it is fixed against rotation.
[0029] In accordance with a further embodiment of the invention, provision may be made for an electromechanical coupling to be provided between the actuating element, which can rotate, on the outside of the door and the magnet, the electromechanical coupling being coupled in a known manner to electronics, which can be activated, for example, with the aid of an encoded microchip in order to supply the electromechanically lockable coupling with an electrical voltage such that the electromechanically lockable coupling latches in so as to open the door. Such an electromechanical coupling is known, for example, from published, non-prosecuted German patent DE 198 29 958 A1.
[0030] Owing to the combination of the magneto-mechanical locking device according to the invention and the electromechanical coupling disposed between the actuating element on the outside of the door and the permanent magnet, the advantage results that the large number of encoding possibilities and the high degree of safety against manipulation of a purely electronic locking device are combined with the advantages of the above-described magneto-mechanical locking device. In this case, it is of particular advantage that the forces for the purpose of rotating the magnet are very low in comparison with known mechanical locks, even in the case of doors having a larger number of locking devices according to the invention, owing to the lack of frictional forces. As a result, both the dimensions of the electromechanical coupling and the current consumption can be kept comparatively low.
[0031] In accordance with a further refinement of the concept on which the invention is based, the longitudinal axis of the rod-shaped or cylindrical permanent magnet is aligned substantially parallel to the vertical, and extends substantially parallel to and in the vicinity of the door edge. For this purpose, the rod-shaped permanent magnet can be inserted in a corresponding pocket or cutout, which is disposed at one end in the door in the region of the vertically extending door edge. In this context, it is likewise conceivable for a rod-shaped permanent magnet, which ensures latching of the door in the region of the upper door edge, to be provided in the same way in the region of the horizontally extending, upper door edge.
[0032] In this embodiment of the invention, the rod-shaped permanent magnets have a comparatively small diameter of, for example, 2 to 5 cm and an accordingly long length of up to 20 cm or more, and are advantageously rotated by a gear mechanism, which is coupled to the actuating element (which can be rotated) and may be, for example, a bevel gear mechanism or another angular gear mechanism.
[0033] The above-described embodiment of the invention has the advantage that both the two vertically extending door edges and the horizontally extending, upper door edge, which is disposed on the upper side of the door, can be used for the purpose of latching the door if two or more magnets are disposed along the edges of the door such that they are coupled via corresponding angular gear mechanisms and the associated regions of the door frame are provided with corresponding striking plates, which are attracted towards the door when the permanent magnets are rotated from the release position to the latching position, in order to latch the door by producing an interlocking connection. At comparatively low actuating forces, a locking device thus results which makes possible highly effective, two-dimensional latching over virtually the entire length of the door edge.
[0034] This embodiment of the invention may provide for two or more permanent magnets to be coupled to one another, via corresponding shafts, such that they are fixed against rotation, it being possible for the coupling to take place, for example, in the corner regions of the door edge by correspondingly configured bevel gear mechanisms or other angular gear mechanisms. A further advantage of this embodiment relates to the fact that the locking device may be of modular configuration in the form of a construction kit, in which case any desired number of rod-shaped permanent magnets are connected to one another via associated shafts, for example by being inserted one inside the other, such that they are rigid in terms of rotation in order to equip a door, a window or the like with a desired number of magnets.
[0035] In accordance with a further embodiment of the invention, the door or window may in this case be provided in a very simple manner with a self-latching mechanism, by which the permanent magnet in its housing is automatically rotated from the release position to the latching position when the door is closed.
[0036] The self-latching mechanism in this case preferably contains a toothed rack, which grips the permanent magnet or a shaft, which is coupled to the permanent magnet such that it is fixed against rotation, via a corresponding pinion, is preferably accommodated in a linear guide in the door and rotates the magnet to the latching position when the toothed rack is displaced in the direction towards the locking element, with the result that the magnetic forces are automatically activated when the door is closed and attract the locking element for the purpose of latching the door.
[0037] The toothed rack is preferably driven via a third permanent magnet, which is, for example, connected to the door frame-side end of the toothed rack and is moved out of the door in the direction towards the locking element when the door is closed owing to a part, which is made from a magnetizable material, for example from an iron plate, of the door frame or else the locking element itself, and as a result moves the toothed rack which for its part again rotates the permanent magnet to the latching position.
[0038] It is possible in the same way to produce automatic rotation of the permanent magnet to the latching position via a lever configuration or the like, which acts on the axis of rotation of the magnet and is likewise actuated by the third permanent magnet.
[0039] This results in a latching mechanism, which operates virtually without wear without the otherwise conventional, very high mechanical complexity and which functions reliably even in the case of greater temperature fluctuations in the event of a change in the distance between the door and the door frame.
[0040] In accordance with a further refinement of the concept on which the invention is based, the housing of the permanent magnet or, generally, the permanent magnet may be surrounded by an electrical coil, in the case of which the coil turns are disposed such that the permanent magnet can be rotated back and forth between the latching position and the release position depending on the direction of an electrical current flowing through the coil. In the preferred embodiment, the coil turns are wound around the housing of the permanent magnet for this purpose such that the longitudinal axis of the coil preferably extends perpendicular to the longitudinal axis of the in this case likewise, if possible, rod-shaped permanent magnet. However, in the same way, other configurations of the coil, through which current flows, are also conceivable.
[0041] This embodiment results in the advantage that the door, for example in the embodiment as a fire-escape door, is opened automatically and centrally in the event of a fire, or, in the embodiment as a fire door, can be latched electrically and automatically without the permanent magnet needing to be rotated by hand for this purpose.
[0042] In accordance with a further refinement of the invention, a displaceable transverse bolt is accommodated on the door in a known manner, the transverse bolt interacting with the permanent magnet via, for example, a further magnet, to be precise such that the transverse bolt is likewise moved to its latching position when the permanent magnet is rotated from the release position to the latching position, as a result of the magnetic force effect. In this case, the magnetic force effect may be produced, for example, by one or more disk-shaped or rod-shaped permanent magnets, which are disposed on that side of the permanent magnet which is opposite the locking element and are moved away from the housing of the permanent magnet, counter to the tensile action of a spiral tension spring or a similar spring-elastic device, when the magnet is rotated to the latching position, owing to the magnetic field produced, with the result that the transverse bolt can engage in a known wall receptacle, which is disposed on that edge of the door frame which lies in the region of the door hinge. The transverse bolt is drawn back out of the wall receptacle in order to release the door in this case once the magnet has been rotated to the release position, at an increased magnetic force owing to the spring-elastic device.
[0043] Finally, a further embodiment of the invention may provide for a pin-shaped or hook-shaped projection, which may have, for example, a T-shaped head and engages in a circumferential accommodating groove (which is formed in a corresponding manner in the magnet and extends towards the center of the magnet such that the, for example, T-shaped head engages in the groove and latches the door in an interlocking manner in addition to the magnetic forces and the interlocking connection of the locking element in the region of the magnet), to be provided on the striking plate or on the locking bolt.
[0044] The circumferential accommodating groove with the cross section extending towards the interior of the magnet may also, however, engage in the same way in a section, which is connected to the magnet such that it is fixed against rotation, is made from a cured material and is rotated together with the magnet.
[0045] Finally, provision may be made for a seal, for example made from rubber or another known sealing material, to be disposed over the entire length of the locking element, the seal moving in the direction towards the door together with the striking plate, with the result that the sealing effect is advantageously produced by the magnetic force effect of the permanent magnet on the locking element. This results in the advantage that reliable sealing of the door or also, possibly, a window is always ensured even in the case of greater changes in the distance between the door frame and the door as a result of seasonal temperature fluctuations.
[0046] Although the invention has already been described in conjunction with a permanent magnet, which is accommodated on the door such that it can rotate, and a locking element, which is provided on the stationary door frame and is made from a magnetizable material, the invention in the same way contains the reverse design, in which the permanent magnet is fixed to the stationary frame such that it can be rotated, and the locking element is preferably accommodated on a door or a window such that it can move.
[0047] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0048] Although the invention is illustrated and described herein as embodied in a magneto-mechanical locking device, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0049] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] FIG. 1 is a diagrammatic, sectional view of a first embodiment of a locking device according to the invention having a locking element, which is accommodated on a door frame such that it can move and is forced away from the door by further permanent magnets, and has a transverse bolt, which is likewise actuated by the permanent magnet, in the latching position;
[0051] FIG. 2 is a diagrammatic, sectional view of the first embodiment from FIG. 1 in a release position;
[0052] FIG. 3 is a diagrammatic, sectional view of a second embodiment of the apparatus according to the invention having a bolt-shaped locking element, which engages in a cutout formed in a housing of a rod-shaped permanent magnet, in the latching position;
[0053] FIG. 4 is a diagrammatic, sectional view of the second embodiment from FIG. 3 in the open position;
[0054] FIG. 5 is a diagrammatic, cross-sectional view of a third embodiment of the invention, which is similar to the embodiment from FIGS. 3 and 4 and in which the permanent magnet is rotated by a rosette-shaped protective fitting, which can rotate, on the outside of the door, in the latching position;
[0055] FIG. 6 is a diagrammatic, cross-sectional view of the third embodiment from FIG. 5 in the release position, once the protective fitting has been rotated;
[0056] FIG. 7 is a diagrammatic illustration of a door having a fourth embodiment of the locking device according to the invention, in the case of which the axes of rotation or longitudinal axes of the rod-shaped permanent magnets extend along the door edges in the vertical and also in the horizontal direction and are driven by angular gear mechanisms;
[0057] FIG. 8 is a diagrammatic, cross-sectional view of a fifth embodiment of the invention having rod-shaped permanent magnets extending along the door edges, in which the locking element is accommodated in a guide within the door frame and is forced away from the door edge into the interior of the door frame by an spring-elastic device, in the latching position;
[0058] FIG. 9 is a diagrammatic, cross-sectional view showing the embodiment from FIG. 8 in the release position;
[0059] FIG. 10 is a diagrammatic, illustration of a self-latching device for the purpose of automatically latching the door once said door has been closed; and
[0060] FIG. 11 is a diagrammatic, illustration of a seventh embodiment of the invention, in which an additional mechanical latching in the closed position of the door is produced by a T-shaped head, which is formed on the locking element and engages in an associated, groove-like opening, which extends towards the center of rotation of the permanent magnet.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0061] Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a magneto-mechanical locking device 1 according to the invention for the purpose of locking a door 4 , which can move with respect to a frame 2 , and contains a locking element 6 , which is fixed to the frame 2 such that it can move via a guide 8 in the direction of arrow 10 .
[0062] The locking device 1 according to the invention also contains a rod-shaped permanent magnet 12 , which is accommodated in a housing 14 made from a magnetizable material such that it can be rotated. Such a magnet is known from the prior art, for example for holding tripods for photographic apparatus or dial test indicators or the like.
[0063] Nonmagnetic, strip-shaped regions 16 are preferably disposed in the magnet housing 14 , which regions may be made from, for example, aluminum and influence the magnetic field produced such that, when the magnet is rotated to the latching position illustrated in FIG. 1 , a magnetic force is exerted on the locking element 6 by the magnetic material via the housing 14 of the magnet and this force attracts the locking element 6 in the direction towards the housing 14 such that projections 18 formed on the locking element 6 engage in associated grooves or cutouts 20 in the door 4 or in the magnet housing 14 and form an interlocking connection which prevents the door 4 from being opened.
[0064] In order to cancel the latching of the door 4 , the magnet 12 is rotated from the latching position shown in FIG. 1 to the release position illustrated in FIG. 2 , in which, owing to the properties of the field strength distribution of the magnetic field, which distribution is influenced by the nonmagnetic regions 16 , the magnetic force is canceled in the region of the locking element 6 . In the position illustrated in FIG. 2 , the locking element 6 made from a magnetizable material is moved away from the housing 14 of the magnet 12 by one or more further permanent magnets 22 , which are disposed on the rear of the locking element 6 and produce a magnetic force which is considerably less than the magnetic force produced by the permanent magnet 12 in the latching position. As a result, the door 4 is unlatched and can be opened in the usual manner, for example with the aid of a door handle.
[0065] As can also be seen in FIGS. 1 and 2 , a door rabbet 24 is formed in a known manner on the door 4 , the rabbet 24 protecting the bearing region, in which the locking element 6 bears against the door 4 or against the housing 14 of the magnet 12 , from manipulations from outside.
[0066] Owing to the very strong attraction forces between the locking element 6 and the permanent magnet 12 in the latching position, extremely effective latching results which can only be canceled in a very complex manner by external manipulations.
[0067] As is also illustrated in FIGS. 1 and 2 , a transverse bolt 26 may also be disposed on the inside of the door 4 , the transverse bolt 26 being provided, at its end facing the magnet 12 , with a third magnet 28 , which is repelled in the latching position shown in FIG. 1 by the field of the rod-shaped permanent magnet 12 and moves the transverse bolt away from the permanent magnet 12 , counter to the action of a tension spring 30 , to the latching position shown in FIG. 1 , in which the second end of the transverse bolt 26 engages in an associated wall receptacle 32 in order to offer additional protection against the door 4 being taken off its hinges.
[0068] In the embodiment of the invention illustrated in FIGS. 3 and 4 , the locking element 6 is in the form of a locking bolt 34 , which is guided in the associated guide 8 in the frame 2 and is forced away from the door 4 in the direction of the arrow 40 by a tension spring 36 or else an additional permanent magnet (not illustrated in any more detail).
[0069] The other end of the bolt-shaped locking element 34 is matched in terms of its shape to the cutout 20 formed in the door 4 or in the housing 14 of the magnet 12 , the end engaging in the cutout 20 in an interlocking manner if the bolt-shaped locking element 34 is moved in the direction of the arrow 40 from the release position shown in FIG. 4 to the closed position shown in FIG. 3 owing to the magnetic forces once the magnet 12 has been rotated.
[0070] As can also be seen from the illustration in FIGS. 5 and 6 , the magnet 12 in the above-described embodiments shown in FIGS. 1 to 4 of the invention is rotated by a known rosette-shaped protective fitting 42 , which can rotate and is described, for example, in the German utility model G 93 17 012 by the Applicant. In this refinement of the locking device according to the invention, a cup-shaped outer part 44 , which can be rotated, is disposed on the outside of the door 4 and can be latched and unlatched by a configuration (indicated schematically in FIGS. 5 and 6 ) of disconnecting pins 46 with respect to an inner part 48 , which is fixedly connected to the door 4 , using a suitable key, is connected in its center of rotation to the magnet 12 with a shaft 50 in a manner which is rigid in terms of rotation, the shaft 50 preferably acting in the center of rotation of the magnet 12 .
[0071] The rosette-shaped protective fitting 42 is reproduced only schematically in FIGS. 5 and 6 , and its details are known from the above-mentioned utility model. The embodiment of the invention illustrated in FIGS. 5 and 6 has a very compact and robust configuration and, owing to the very large number of encoding possibilities of the rosette-shaped protective fitting 42 , has a very good protective action.
[0072] The position, illustrated in the figures of the magnet 12 within the housing 14 for release and latching is only exemplary and can be changed, if desired, depending on the respective requirements for the displacement path by corresponding polarization of the magnet. It is thus conceivable, for example, to use a quadrupole magnet in order to obtain a corresponding reduction in the angle of rotation between the latching position and the release position.
[0073] In accordance with a further embodiment of the invention illustrated in FIG. 7 , one or preferably even two or more rod-shaped magnets 12 are disposed in the region of the door edge, the longitudinal axis of the permanent magnets 12 extending substantially parallel to the door edge.
[0074] As can also be seen from the illustration in FIG. 7 , the magnets 12 are coupled to one another via corresponding shafts 52 and are driven by known angular gear mechanisms 54 , which are in the form of bevel gear mechanisms in the embodiment in FIG. 7 .
[0075] In addition to the magnets 12 extending in the vertical direction, one or more magnets 12 extending in the horizontal direction may be disposed in the region of an upper edge 56 , which interact with one or more locking elements 6 in the same manner as the other magnets, the locking elements 6 being accommodated in schematically illustrated guides 8 such that they can move and being attracted, depending on the position of rotation of the magnets 12 , in the above-described manner counter to a resetting force, which is produced, for example, by further permanent magnets 22 , so as to latch the door 4 .
[0076] In this embodiment of the invention too, the rotation of the permanent magnets 12 from the release position to the latching position is preferably produced by a rosette-shaped protective fitting 42 .
[0077] In this embodiment of the invention, the locking elements 6 are preferably in the form of continuous striking plates, to which a sealing element is advantageously fixed, the sealing element extending over the entire length of a locking element 6 , but not being illustrated in FIG. 7 for illustrative reasons.
[0078] As can be seen from the cross-sectional view of the embodiment from FIG. 7 in FIGS. 8 and 9 , the locking element 6 , which extends over the entire length of the door or at least over a section of the door, engages in a correspondingly configured longitudinal groove-like cutout 60 in the door 4 with correspondingly tab-shaped projections 58 in the latching position shown in FIG. 8 and thus forms an interlocking connection over the entire length of the door edge in the latching position.
[0079] In the release position illustrated in FIG. 9 , the locking element 6 , as a deviation from the illustration in FIG. 7 , is drawn into the door frame 2 by a spring-elastic device in the form of a tension spring 36 .
[0080] As can be seen from the illustration in FIGS. 8 and 9 , the permanent magnet 12 in this embodiment of the invention is likewise accommodated in the housing 14 , which can be inserted in a correspondingly shaped pocket in the region of the door edge and preferably extends over the entire length of each individual magnet 12 .
[0081] In order to obtain automatic latching of the door described in FIGS. 7 to 9 , a self-latching mechanism 62 is preferably disposed in the door in the region of the door edge, the mechanism 62 contains a toothed rack 64 , which can be moved in the direction of double arrow 66 in a guide (not described in any more detail).
[0082] The toothed rack 64 is in toothed engagement with a pinion or toothed wheel 68 , which is coupled, such that it is fixed against rotation, to one of the shafts 52 or else directly to the magnet 12 drawn schematically in FIG. 10 using dashed lines.
[0083] That end of the toothed rack 64 which is close to the door frame 2 is preferably connected to a third permanent magnet 70 , which is moved in the direction towards the locking element 6 or door frame 2 when the door 4 is closed owing to the interaction with the locking element 6 , or with a corresponding magnetizable part of the door frame 2 , and, as a result, sets the toothed wheel 68 in rotation, the toothed wheel 68 for its part rotating the magnet 12 from the release position to the closed position.
[0084] In order then to again cancel the latching of the door thus produced, the magnet 12 is then rotated back to the release position by the associated gear mechanism 54 and the actuating device, which may take place generally only with the aid of the associated key when a rosette-shaped protective fitting 42 is used.
[0085] In order to make possible free rotation of the toothed wheel 68 when the actuating element or protective fitting 42 is blocked, the gear mechanism or else the rosette-shaped protective fitting 42 may be provided with a correspondingly configured free running state or a one-way coupling, which is not illustrated in any more detail in the drawings for illustrative reasons.
[0086] In accordance with the embodiment of the invention illustrated in FIG. 11 , the locking element 6 in the embodiment from FIG. 7 has an end section, which is provided with a T-shaped head 72 and engages, in the latching position of the magnet 12 , in a groove-like or pocket-like cutout 74 , which engages in the magnet 12 or in a section 76 , which is connected to the magnet 12 such that it is fixed against rotation and is made from a cured material, in order to ensure additional mechanical latching of the door 4 in the latching position of the magnet.
[0087] Finally, in accordance with a further embodiment of the invention, which is indicated schematically in FIG. 4 , an electrical coil 80 may be formed around the permanent magnet 12 , the coil turns of the electrical coil 80 being aligned such that the magnetic field produced rotates the permanent magnet 12 from the latching position to the release position and back depending on the direction of the electrical current flowing through the coil 80 . The coil 80 is only shown in FIG. 4 for illustrative reasons. The coil makes it possible for the locking device 1 according to the invention to be provided with electrically controlled emergency latching or emergency unlatching, which makes possible, for example in the event of a fire, central opening of all of the emergency exit doors of a building.
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A magneto-mechanical locking device for locking a door can be displaced in relation to a stationary frame. The locking device contains a locking element produced from a magnetizable material and disposed on the frame. The locking device further has a permanent magnet that is mounted on the door and can be twisted from a first release position, in which the locking element is subject to substantially no action of magnetic force, to a second locking position, in which the locking element is attracted by the action of magnetic force of the permanent magnet and locks the door.
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BACKGROUND OF THE INVENTION
The invention relates to an apparatus for mixing and a method of mixing propellant charge powder rods.
It is conventional to produce propellant charge powders in individual batches. To a certain extent the properties of the propellant charge powder vary from batch to batch because the manufacturing conditions prevailing during production of a batch are not precisely reproducible for another batch. Therefore, different batches of any one type of powder are mixed together in order to minimize the spread of the propellant charge powder characteristics around a given medium value, thus obtaining uniform quality in the long run.
Where the propellant charge powder is available in the form of sticks or rods, the mixing so far is carried out manually, with strict observance of mixing rules, for example by exchanging certain proportions of batches of propellant charge powder rods positioned side by side on a mixing table. Although attempts have been made in the past to mechanize the mixing process by the use of mixing drums, they did not meet with success since the propellant charge powder rods assumed oblique positions in the mixing drum, becoming jammed with one another, and impeding the further movement of the rods so that mixing no longer took place. Another disadvantage of the mixing drum method became evident in emptying the mixing drums: Prior to being able to pass on the unaligned, crisscross heap of rods to further steps in the production, they had to be fed to a vibrating or sorting device for proper alignment.
It is the object of the instant invention to indicate an apparatus and a method by which to mix propellant charge powder rods mechanically.
SUMMARY OF THE INVENTION
This object is met, in accordance with the invention, by an apparatus for mixing propellant charge powder rods, comprising a flexible band which is suspended freely in a loop between two paraxial, radially spaced drums and movable back and forth between the drums by drive means.
The object further is met by a method of mixing propellant charge powder rods, wherein the propellant charge powder rods are placed in the upwardly open, freely suspended loop of a flexible band, in parallel with the plane thereof, and thereupon the band in the loop is moved back and forth at least once.
The expressions "propellant charge powder rods" or "powder rods" in the sense of the instant invention are to be understood as comprising also propellant charge powders or powders which differ from the usual cross sectional shape of a "rod or stick" in that their cross section is perforated, tubular, polygonal or in any other way different.
The invention provides for positioning the propellant charge powder rods with their longitudinal extension transversely of the direction of movement of the flexible band in the suspended loop of the band and mixing them by moving the band back and forth between the (loop) drums. That makes the propellant charge powder rods roll above and below one another, while maintaining their lengthwise alignment, and intensive mixing takes place.
The solution proposed by the invention eliminates the cumbersome mixing by hand so that a reduction in production cost can be achieved. Moreover, the mixing of propellant charge powder rods of different batches is very good and uniform. On the whole, the apparatus and method according to the invention are suited to simulate the course of the conventional manual mixing which follows precise specifications with the advantages of mechanization (e.g. reliability, lower costs). Adaptation to the various specifications for mixing can be obtained, for instance, by connecting in series several apparatus according to the invention or by carrying out the method according to the invention in a plurality of successive courses following different mixing specifications.
Another advantage of the apparatus and method according to the invention is to be seen in the fact that the specific safety requirements involved in the handling of propellant charge powders are fulfilled to a high degree by the mechanical realization of the mixing process.
Advantageous further developments of the apparatus and method according to the invention are described below.
For instance, two alternatives are suggested in examplary fashion for the design of the flexible band. With the first one, the band is endlessly closed band and, outside of the loop, it passes around at least one drive drum adapted to be driven in either direction of rotation. In the case of the other alternative, the flexible band is finite and runs back and forth between two winding drums, each adapted to be driven in either direction of rotation. In both cases preferably the loop drums are designed as deflecting drums.
Regarding the second alternative of the flexible band, it is advantageously provided in connection with the deflection drums that the band runs directly from each deflecting drum to one each of the two winding drums.
A further development according to which the length of the flexible band is variable in the loop between the two loop drums or deflecting drums is particularly advantageous for the mixing process. This makes the bending line of the loop of the band variable and, as a consequence, especially the propellant charge powder rods roll over above and below one another still more intensively.
An extension of the loop beyond a certain size or full tightening of the flexible band during the mixing operation both are avoided by furnishing the apparatus with switching mechanisms detecting the greatest extension of the loop, for example, by a sensor positioned below the band at the periphery thereof. An examplary sensor may be a capacitive sensor. Two further inductive sensors cooperating with copper strips at the band ends effect the changeover for moving the band back and forth periodically.
Again two alternatives are proposed, by way of example, for varying the length of the flexible band in the loop. According to the first one, at least one compensating roller is associated with the band outside of the loop and can be adjusted radially to change the length of the loop. The second alternative advantageously provides for the length of the loop to be varied by driving the two winding drums at different circumferential speeds. In principle, different directions of rotation of the winding drums would be conceivable as well.
Advantageously, a control means may be provided to change the loop length periodically between minimum and maximum values during the back and forth movement of the band as that will lead to further improvement of the result obtained by the mixing.
Preferably, at least one of the two loop drums is adjustable in height, whereby at least one of the points of deflection can be raised or lowered. One-sided raising of one of the loop drums and/or simultaneous lowering of the other loop drum, if desired, makes it possible to tighten the flexible band so that it will present an inclined plane for automatic emptying of the apparatus. The adjustable gradient of the inclined plane will then permit the mixed propellant charge powder rods to be loaded gently into ready containers or onto conveyor belts moving them on or into further mixing apparatus. Automatic loading of the apparatus with powder rods is possible by means of this further development of the invention: Adjustment of a correspondingly slight sagging of the band in its inclined plane position by making the band longer between the loop drums permits the powder rods to be rolled gently into the depression thus formed. For mixing, the band length between the loop drums is increased still further so that a sagging loop is obtained once more.
The flexible belt with an antistatic finish may be a commercially available conveyor belt. Furthermore, it may be provided at the side facing the interior of the loop with transverse studs, preferably of triangular cross section, to further enhance the thorough mixing of the propellant charge powder rods.
Especially preferred is the provision of a limiting wall at either of the open ends of the loop formed by the band, these limiting walls extending transversely of the plane of the band and at a spacing from each other which is a little greater than the length of the propellant charge powder rods. These limiting walls advantageously serve to prevent the propellant charge powder rods from falling off while being mixed.
Advantageously, the spacing between the two limiting walls is adjustable for adaptation to the length of the powder rods and, if desired, the band is replaceable by a wider or a narrower one as this will permit the mixing of powder rods of any desired length.
Advantageous further developments of the method according to the invention essentially relate to various measures of influencing the reciprocating movement of the flexible band. For example, it is advantageous to vary the length of the band in the loop periodically between minimum and maximum values during the back and forth movement. Preferably, the minimum value of the length of the band in the loop is between 40 and 50% of the maximum value of the length of the band.
Further indications relate to preferred values of the speed of the band, which is stated as corresponding to an average value of some 3 meters per minute, the duration of the period of one back and forth movement of the band, stated as being between 2 and 30 minutes, and the duration of the period of one loop change, stated as being a value between 10 and 150 seconds.
For further mechanization of the process, preferably it is provided that the weight of the propellant charge powder rods introduced is determined during the loading of the apparatus, and the loading operation is stopped automatically in response to a comparison to be made of the weight determined with the desired weight of a load and the mixing operation is started when the desired weight of the loading has been reached.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described further, by way of a preferred embodiment, with reference to a drawing, in which:
FIG. 1 is a side elevation of the apparatus with a finite band,
FIG. 2 is a front elevation of the apparatus, looking in the direction of X in FIG. 1,
FIG. 3 is a view similar to FIG. 1, but illustrating a further embodiment of the present invention with an endless band.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an apparatus for mixing propellant charge powder rods 30 including a box-like machine frame which is adapted to roll. The machine frame comprises four vertical beams of which only the vertical beams 10, 11 are to be seen in this presentation. The vertical beams 10, 11 as well as the other two vertical beams behind them in the plane of the drawing are interconnected by respective lower and upper longitudinal beams 19,20. Between these longitudinal beams 19,20 two transverse beams 21,22 each are received in pairs with the aid of upper guide bars 23 and lower guide bars 24 (FIG. 2). For easier movement of the machine frame, the vertical beams are provided at the bottom with rolls 12.
The vertical beams 10,11 and the vertical beams behind them support the loop drums 2,3 designed as deflecting drums for the flexible band 1 which is suspended in a loop between the deflecting drums 2,3. In this embodiment the flexible band 1 is embodied by a finite band which passes around each deflecting drum 2,3 directly to a winding drum 4,5 each arranged at the transverse sides of the machine frame. The winding drums 4,5 are adapted to be driven--preferably at different circumferential speeds--by drive means 6,7 likewise arranged at the transverse side of the machine frame. The drive means 6,7 are embodied by frequency-controlled, explosion-proof motors of conventional type having a high step-up ratio which are connected to the winding drums 4,5 by a belt drive. As an alternative of the belt drive a chain drive may be used. The flexible band 1 runs from its one end wound around the winding drum 4 over the deflecting or loop drum 2 and, forming a bending line and being supported on the upper transverse beams 21, over the other deflecting or loop drum 3 to the second winding drum 5. If the winding drums 4,5 are driven at different circumferential speeds the flexible band 1 becomes longer or shorter and the periphery of the bending line of the flexible band 1 moves in vertical direction between a maximum value and a minimum value. It depends on the filling of the flexible band 1 and on the length thereof whether or not it is supported on the lower transverse beams 22 (FIG. 2). The flexible band 1 may be provided on its side facing the interior of the loop with transverse studs 31 which promote the mixing of the powder rods 30 introduced.
At the two open sides of the loop of the band 1 there is a limiting wall 8,9 each extending transversely of the plane of the band 1 and being displaceable in transverse direction on the upper and lower guide bars 23,24, respectively (FIG. 2). Hereby their lateral spacing is variable to adapt it to different lengths of the propellant charge powder rods 30. At the bottom end, the lateral limiting walls 8,9 essentially have a shape which is adapted to the suspended loop of the flexible band 1.
In the embodiment shown in FIG. 1, the deflecting or loop drum 3 is designed to be movable in vertical direction by a drive means housed, for instance, in the vertical beam 11 and consisting, for instance, of an hydraulic piston and cylinder arrangement 13,14. The vertical adjustability of the deflecting drum 3 makes it possible to tighten the flexible band 1 so as to present an inclined plane for discharge purposes, as may be seen in FIG. 1 by the discontinuous presentation of the deflecting drum 3' and of the band 1'. In this presentation of the band 1' in discontinuous lines, the propellant charge powder rods 30 may roll sideways off the band 1' into ready containers or onto conveyor belts which lead them on.
FIG. 2 shows the apparatus looking in X direction of FIG. 1. The two neighboring vertical beams 11,11' support the bearings 18 for the deflecting drum 3 which is movable vertically in the direction of arrow 26 by a drive means described in exemplary fashion above. Below the deflecting drum 3, in the presentation, yet not in the same vertical plane, there is the upper transverse beam 21 which is connected to the longitudinal beam 19 by the upper guide bar 23 (FIG. 1). The bearings 15 for the winding drum which takes up one end of the flexible band 1 are fastened to the vertical beams 11,11'. At its driven end, the winding drum 5 possesses a pulley 16 which is operatively connected by a belt to a pulley 17 underneath belonging to the drive means 7 which is fastened to the vertical beam 11.
The lateral limiting walls 8,9 can be shifted axially in the direction of arrow 25 on the upper and lower guide bars 23,24, respectively, into the positions shown in discontinuous lines and marked by reference numerals 8', 9' so as to adapt them to propellant charge powder rods of different lengths. The radial flanges 27,28 at the deflecting drums 2,3 and at the winding drums 4,5, respectively, also are movable axially, likewise in the direction of arrow 25, in order to permit the use of a flexible band 1 of greater width as well. The two drive means 6,7 are connected to a control means as schematically illustrated in FIG. 1 for periodically changing the length of the loop between minimum and maximum values, while the band moves back and forth.
The method according to the invention of mixing propellant charge powder rods will be described with reference to the apparatus specified above and preferably takes place as follows:
First of all, the powder rods 30 are placed in the upwardly open, freely suspended loop of the flexible band 1 in such manner that the longitudinal extension of the powder rods 30 is transversely of the direction of movement of the band 1 in the loop. During the loading operation the weight of the powder rods 30 added is determined by a suitable device, not explained in detail here, and the loading operation is stopped as the desired weight of a batch is being reached.
During the mixing process which begins subsequently the flexible band 1 carries out motion which is composed of two basic movements being superimposed over each other. The first basic movement of the band 1 is produced by the winding drums 4,5 rotating at the same winding speed and one of them taking up the band 1, while the other one pays off the band 1. During this basic movement the band 1 runs at constant band velocity between the two deflecting drums 2,3, maintaining its loop configuration. The direction of movement of the band 1 is reversed automatically when the end of the band on the winding drum which pays off has been reached.
The second basic movement of the flexible band 1 consists in both winding drums 4,5 either winding or unwinding, whereupon the band length between the two deflecting drums becomes shorter or longer, respectively, and the loop carries out movement in vertical direction while changing its bending line. During this basic movement, too, suitable means for measuring and reversal make sure that the band 1 is neither tightened completely nor touches the ground.
The resultant motion which is utilized in the mixing operation is obtained by one of the winding drums 4,5 winding up the band 1, while the other one unwinds it, with the two winding drums 4,5 rotating at different winding speeds. As a result, the band 1 moves according to the first basic movement and, at the same time, the loop becomes shorter or longer by virtue of the different winding speeds of the winding drums 4,5, i.e. it moves in vertical direction. The second basic movement is realized in that the winding drums 4,5 effect winding or unwinding of the band 1, based on their different winding speeds. During this operation, the duration of the period of shortening or lengthening of the loop--according to the second basic movement--is shorter than the reciprocating movement of the band 1 in the loop in accordance with the first basic movement. At an average band velocity of 3 m/min. the duration of the period for shortening or lengthening the loop is 30 seconds, the period duration for back and forth movement of the band 1 is 3 minutes, and the overall time of treatment provided for one batch is 15 minutes.
FIG. 3 illustrates an embodiment of the present invention wherein the band 1 is endless, and the means for driving the belt comprises drive drums 4, 5 which are each positioned so as to engage the band at a location outside of the loop. As in the first embodiment, the drums 4, 5 of FIG. 3 are adapted to be driven in either direction of rotation by a suitable control.
In the drawings and specification, preferred embodiments of the invention have been disclosed, and although specific terms are employed, they are used in a generic sense only and not for purposes of limitation.
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A method for mixing propellant charge powder rods utilizes a flexible band (1) which is suspended freely in a loop between two paraxial, radially spaced drums (2,3) and is movable back and forth between the drums (2,3) by drive motors (6,7). The band (1) is finite or endless and movable in reciprocation between two winding drums (4,5) each adapted to be driven in either direction of rotation by the drive motors (6,7). The propellant charge powder rods (30) are placed in the suspended loop of the flexible band (1)--transversely of the longitudinal direction of the band--and are mixed together by moving the band (1) back and forth. The length of the loop is increased and decreased periodically during this process.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method and an apparatus for diffusing zinc (Zn) into groups III-V compound semiconductors. The groups III-V compound semiconductor means a semiconductor of a pair of a group III element gallium(Ga), indium(In) or aluminum(Al), and a group V element arsenic(As), phosphorus(P) or antimony(Sb). Bulk single crystal wafers are available for GaAs, InP and GaP. GaAs wafers, InP wafers and GaP wafers are useful as substrates of laser diodes (LDs), light emitting diodes (LEDs), photodiodes (PDs) or other semiconductor devices. Though this invention can be applied to any III-V compound semiconductor wafers, explanation will be done by only citing GaAs and InP.
The III-V compound semiconductor wafers are inherently n-type in many cases. Fabrication of a pn-junction requires epitaxial growth of p-type thin films on the n-type wafer, ion implantation of a p-type impurity, or thermal diffusion of a p-type impurity into the n-type wafer. The epitaxial growth of the p-type films is improper for making localized p-regions through a mask. The ion implantation is not the most suitable, since it requires a large apparatus, a plenty of steps and annealing of the ion implanted wafer, which raise the cost of producing the pn-junction. The thermal diffusion is the most suitable way for making pn-junctions in an n-type wafer. Zinc (Zn) acts as a p-type impurity in GaAs or InP crystals. Magnesium (Mg) and cadmium (Cd) are also p-type impurities in GaAs or InP, but Zn is the most feasible p-impurity for InP or GaAs. Zn-diffusion is one of the most important techniques of fabricating LEDs, LDs, PDs and other semiconductor devices having the group III-V semiconductor substrates. The purpose of the Zn-diffusion is to make localized p-regions on a crystal by diffusion.
Here, the crystal includes substrate crystals and film crystals grown on substrate crystals. A purpose of the present invention is to provide a new Zn-diffusion method and apparatus applicable to a wide wafer. Another purpose of the present invention is to provide a Zn-diffusion method and apparatus of high controllability. A further purpose of the present invention is to provide a Zn-diffusion method and apparatus immune from the use of poisonous materials.
This invention is a version of vapor phase diffusion methods but is different from conventional vapor phase diffusion methods. This invention is rather akin to liquid phase epitaxy (LPE). This invention rather diverts the manner and the device from the liquid phase epitaxy to the Zn-diffusion. Though this invention resembles the liquid phase epitaxy, this invention is essentially a vapor phase diffusion of Zn. Instead of material liquid, a vapor of Zn is filled in a sliding jig. This invention is not epitaxy but diffusion. This invention must be clearly discriminated from the liquid phase epitaxy.
This application claims the priority of Japanese Patent Application No.10-213954(10-213954) filed on Jul. 29, 1998 which is incorporated herein by reference.
2. Description of Prior Art
Impurity diffusion is classified into two categories of vapor phase diffusion and solid phase diffusion by the distinction whether the impurity is supplied from solid phase or vapor phase. There is no concept of “liquid phase diffusion”. The solid phase diffusion is a new technology recently proposed by the present Inventors for the first time (Japanese Patent Application No.5-177233, Japanese Patent Laying Open No.7-14791). The solid phase diffusion method has steps of growing a Zn-containing InGaAsP film epitaxially on an n-InP crystal substrate and diffusing Zn from the InGaAsP film into the InP substrate by heat. Since the object InP is protected by the InGaAsP film, P atoms do not escape from the bottom InP substrate in spite of heating in the solid phase diffusion. However, an excess number of steps have been prohibiting the practical use of the solid phase diffusion.
The Zn-diffusion is still actually done exclusively by vapor phase diffusion. The vapor phase diffusion is further classified into two methods. One of the vapor phase diffusion methods is a closed tube method. The other is an open tube method. Both two methods are well known. But only the closed tube method is put into practice on a large scale in the semiconductor industry at present. The open tube method is poorly employed on a small scale in some laboratories, because the open tube method is still suffering from unsolved difficulties. Two methods are explained in detail for clarifying the present state of the art of impurity diffusion.
[A. Closed tube method]
FIG. 14 shows a closed tube method for diffusing Zn into a group III-V semiconductor wafer. A long quartz tube 61 having an open end and a closed end is prepared. An InP wafer (or GaAs wafer) 62 is put on an inner spot near an end 60 of the quartz tube 61 . A diffusion source 66 is put on an inner point near the other end 65 of the quartz tube 61 . The quartz tube 61 is vacuumed and the open end is sealed by an oxygen-hydrogen flame burner. Sometimes the quartz tube 61 necks in a part 63 containing the solid diffusion source 66 . The Zn diffusion source 66 is either a sublimable compound of Zn and As or a sublimable compound of Zn and P. For example, zinc phosphide (ZnP 2 ), zinc arsenide (ZnAs 2 ) or so is selected as a material of the Zn-diffusion source, because they satisfy the conditions of inclusion of Zn, sublimability from solid phase to vapor phase and immunity from foreign materials except Zn and the substrate material. This method is called a closed tube method, because the quartz tube is fully closed.
The sealed quartz tube 61 is put into a horizontal furnace having heaters 67 and 68 . The furnace heaters 67 and 68 heat the whole of the quartz tube 61 and maintain the Zn-diffusion source 66 at a higher temperature than the wafer 62 . The Zn-diffusion source 66 sublimes into vapor at the higher temperature. The vapor flies in the quartz tube to the wafer 62 of GaAs or InP and adheres to the wafer at the lower temperature. The Zn atoms diffuse deeply in the wafer by heat. The diffusion depth in the wafer can be controlled by the temperature and the time. After the determined time has passed, the temperature of the furnace is reduced. When the furnace is cooled to a pertinent temperature, the quartz tube 61 is pulled out of the furnace. The object GaAs wafer (or InP wafer) is taken out by breaking the quartz tube 61 . The wafer is provided with pn-junctions by the Zn-diffusion.
FIG. 15 shows an improvement of the closed tube method. A long quartz tube 70 is prepared. A diffusion source 76 is put in at an end 75 of the quartz tube 70 . A GaAs wafer (or an InP wafer) 74 is placed in a half-closed short tube 73 . The half-closed tube 73 is put in at a middle of the quartz tube 70 . A vacuum is formed in the quartz tube 70 and the tube end is sealed by the oxygen-hydrogen flame burner. The closed tube is inserted into a furnace having heaters 79 , 80 and 82 . The diffusion source 76 is heated to the highest temperature by the heater 79 for subliming the source material. The middle part of the tube is heated at the lowest temperature by the heater 80 for converting the diffusion material vapor into powder and once depositing the powder 78 on the inner wall. Then, the powder 78 is heated for flying to the GaAs wafer 74 for depositing on the wafer. There are some new proposals of the close tube methods other than the method of FIG. 15 .
Why the tube must be sealed in the closed tube method? The sealing is required for the necessity of controlling the vapor pressure of the group V element (As or P). The closed space enables the dissolving speed of the diffusion source to uniquely determine the vapor pressure of the group V element. The dissolving speed is determined only by the temperature T of the diffusion source. Namely, in the closed tube, the vapor pressure is controlled only by the temperature T of the diffusion source. Maintaining the balance between the dissolution and the absorption of the group V element on the wafer surface, the close tube method carries the Zn compound in vapor phase from the diffusion source to the wafer, deposits the Zn atoms on the wafer and diffuses the Zn atoms deeply into the wafer.
The time and the temperature determine the depth and the concentration of diffusion. Only the closed tube method among various diffusion methods is practically used on a large scale in the semiconductor industry. The closed tube method has many advantages. The wafers are immune from contamination, because Zn is diffused in a closed space separated from the external environments. A great amount of gas is unnecessary. The wafers are not oxidized. The diffusion is stable. The reliability of diffusion is high in the case of deep diffusion. The closed tube method is a matured technique having a long, rich history. Since it is already an old, ripened technique, it is difficult to cite an original document which describes the typical closed tube method. Instead, some proposals for improvements will be explained now.
{circle around (1)} Japanese Patent Laying Open No.60-53018,“method of diffusing impurities into a compound semiconductor” suggested a new way of vapor phase diffusion of zinc (Zn) into InP. Pointing out a problem of prior diffusion of an excess diffusion speed caused by sealing only an InP wafer and a diffusion source of ZnP 2 or Zn 3 P 2 , {circle around (1)} proposed an addition of a solid phosphorus (P) in the close tube for decreasing the diffusion speed. When the closed quartz tube is heated, the P-vapor pressure is raised by the sublimation of the newly added P solid in the closed tube. The Zn-vapor pressure is suppressed by the P-vapor pressure, since the total pressure is restricted by the temperature. The addition of the P-vapor pressure reduces the diffusion speed through the decrement of the Zn-vapor pressure. The solid P plays the role of retarding the diffusion of Zn.
Why must the closed tube method cut down the diffusion speed? Would the high speed diffusion bring about high throughput? It is, however, wrong. Large heat capacity accompanies the quartz closed tube owing a large length and a big thickness. It takes about 15 minutes to heat the quartz tube up to a temperature between 500° C. and 600° C. in the furnace. But the time of diffusion for making a 2 μm deep p-region is only 10 minutes due to the rapid diffusion. It takes several tens of minutes to cool the furnace for decreasing the temperature to room temperature. Heating and cooling of the whole of the quartz tube require a long time due to the large length and the big thickness.
The large heat capacity allows the quartz tube to change the temperature moderately and continually but forbids the tube from varying temperature rapidly. The sublimation of the diffusion source and the Zn-diffusion start even at the step of rising temperature due to the slow change of temperature. The diffusion still continues even at the step of cooling. The diffusion also occurs at extra steps other than the diffusion step. Since the closed tube method controls the diffusion only by temperature, it is impossible to control the start and the end of the diffusion exactly. Since heating and cooling require a longer time than diffusion, the depth of diffusion cannot be correctly determined. There is another problem of the contamination of the wafer by the Zn, because condensed Zn comes to adhering to the wafer surface at the step of cooling. For overcoming these drawbacks, {circle around (1)} tried to suppress the extra diffusion accompanying the heating step and the cooling step by supplying the P solid in the quartz tube, raising the P-vapor pressure and decreasing the Zn-vapor pressure.
[B. Open tube method]
A quartz tube having openings at both ends is prepared. The open tube method diffuses Zn into an InP wafer or a GaAs wafer by supplying the InP wafer (or GaAs wafer) into the quartz tube, heating the tube to a pertinent temperature, supplying a Zn-containing metallorganic gas and a As- or P-containing gas, for example, arsine (AsH 3 ) or phosphine (PH 3 ) into the open quartz tube. The Zn-containing metallorganic gas is prepared from a metallorganic compound having Zn which is liquid at room temperature, for example, dimethyl zinc (Zn(CH 3 ) 2 ). The Zn-containing metallorganic gas is made by bubbling the metallorganic compound with hydrogen gas. The Zn-containing gas is introduced into the quartz tube from an opening end and becomes in contact with the heated GaAs (or InP) wafer. The metallorganic gas (e.g.,dimethyl zinc) is dissociated by heat into zinc atoms and hydrocarbons. Zn atoms are adsorbed on the surface of the wafer. Zn atoms cover the surface of the wafer. High temperature gives the wafer a high diffusion coefficient. Zn atoms diffuse from the surface to the inner part along with the inclination of the Zn-concentration.
If the wafer were to be bluntly heated in vacuum, the group V atoms would escape from the surface of the III-V wafer owing to the high dissociation pressure at a high temperature. The open tube method introduces PH 3 gas or AsH 3 gas for heightening the vapor pressure of the group V element in order to forbid the group V atoms from dissociating out of the surface. The high pressure of the group V gas balances the dissociation with the adsorption of the group V atoms on the surface of the wafer. The balance of the open tube method is a dynamic balance in which the flowing gas (PH 3 or AsH 3 ) protects the wafer from dissociation in stead of perfect equilibrium by the static gas. The open tube method is inferior to the closed tube method in the vapor pressure balance. Since the tube is not sealed, the open tube method, however, can treat far larger wafers than the closed tube method. Possibility of processing a large sized wafer is the most conspicuous feature of the open tube method. Another advantage is the sparing of quartz tubes. Someone considers that the open tube method may excel in controllability, because the gas flows are ruled by valve operations. The open tube method, however, has not been practiced on a large scale in factories of the semiconductor industry yet, but has been adopted only for the purpose of experiments in some universities. For example,
{circle around (2)} T. Tsuchiya, T. Taniwatari, T. Haga, T. Kawano, “High-quality Zn-diffused InP-related materials fabricated by the open-tube technique”, 7th International Conference of Indium Phosphide and Related Materials p664 (1995, Sapporo) reported a Zn-diffusion by supplying a mixture gas of hydrogen (H 2 ), dimethyl-Zn, phosphine (PH 3 ) to an InGaAsP/InP epitaxial wafer in an MOCVD apparatus. Instead of preparing an inherent open tube diffusion apparatus, the MOCVD apparatus was diverted to an open tube method for diffusion. Since the open tube method requires only a heater and an enclosed space which allow gases to flow, the MOCVD apparatus can be a substitute for the quartz tube in the open tube method. Temporary diversion of the MOCVD apparatus on a small scale can be allowed. However, the MOCVD is an apparatus not for diffusion but for epitaxy. Such a high cost diversion would be forbidden on a large, industrial scale.
{circle around (3)} Japanese Patent Laying Open No.62-143421 “method and apparatus for diffusing an impurity” proposed an improvement of the open tube method. It denied the closed tube method for the reason that the diffusion starts midway of the step of rising temperature. FIG. 16 shows the proposed improvement having a horizontal quartz tube 83 with inlets 85 and 86 , and an outlet 87 . An InP wafer 84 is put at a spot near the outlet 87 within the quartz tube 83 . A Zn-source 88 (Zn 2 P) is laid at another spot near the inlet 86 in the quartz tube 83 . An inactive gas is supplied into the tube 83 via the middle inlet 85 . The flow of the inactive gas can separate the InP wafer 84 from the Zn-source 88 . During the steps of rising temperature (heating step) and decreasing temperature (cooling step), the InP wafer 84 is effectively separated from the Zn-source 88 by blowing the inactive gas into the tube 83 from the middle inlet 85 . During the step of diffusion, the flow of the inactive gas is stopped and hydrogen gas is supplied into the tube 83 from the end inlet 86 . The hydrogen gas carries the vapor including Zn from the Zn-source 88 to the InP wafer 84 . The Zn atoms are adsorbed on the surface of the wafer 84 . The high temperature forces the Zn atoms to diffuse into the InP crystal. Operation bars penetrate into the tube through the side valves 89 and 90 for conveying the wafer 84 and the diffusion source 88 . The swift change of the gases enables the open tube apparatus to forbid the diffusion from occurring during the cooling step and the heating step. The advocates assert that the open tube method can control exactly the depth of diffusion through the timely control of the gas flow.
The closed tube method is endowed with strong points of controllability of the group V gas pressure, saving of material gases, immunity from contamination and practical achievements. Despite many proposals, only the closed tube method is a practical Zn-diffusion method which has been widely carried out on a large scale in the semiconductor industry. The closed tube method, however, is suffering from a drawback of the difficulty of treating large-sized wafers. Since the closed tube method inserts an object wafer into a quartz tube (ampoule), the quartz tube having an inner diameter larger than the outer diameter of the object wafer should be employed. Not automated manipulators but skilled workers still do all the diffusion steps of inserting a wafer, putting an impurity source in a transparent quartz tube, making the tube vacuous and sealing an open end of the quartz tube by a oxygen-hydrogen flame burner. The formidable difficulty forces the experienced technician to handle the sealing step, excluding the possibility of the automatic sealing by a machine. The high melting point of quartz compels the technician to use the oxygen-hydrogen burner. The sealing operation includes the steps of evacuating the tube by a vacuum pump, softening a part of the quartz tube by the burner flame, narrowing the softened part, shutting the tube at the narrowing part, separating the other part of the quartz tube which is still evacuated by the vacuum pump and rounding the separated end of the part containing the wafer and the diffusion source by the burner. All the steps are done by manual operation of the skilled technician.
An increase of the diameter of the quartz tube raises the difficulty of the vacuum sealing of the quartz tube. One-inch diameter InP wafers have been used so far for making LEDs, LDs, PDs or other devices. But two-inch wafers will be employed for making the devices in near future for enhancing the throughput of the wafer process. If a two-inch diameter InP wafer should be inserted into a 3 mm-thick quartz tube, the outer diameter of the quartz tube would be at least 56 mm. It is extremely difficult even for an expert to seal such a wide quartz tube having a diameter of at least 56 mm. The vacuum sealing of the wide quartz tube requires an exquisite skill of an experienced technician.
The closed tube method has another weak point of the necessity of breaking the transparent, expensive quartz tube for taking the treated wafer out. The broken quartz tube cannot be reused. The broken parts of the expensive quartz tube must be thrown into a garbage pit. It is a waste of expensive natural resources. Further, since the quartz tube is broken down, the fragments are spattered. Some of the fragments adhere to the wafer. Further, the spattered fragments sometimes hurt the wafer.
There is a further drawback in the current closed tube method. It is poor controllability, since the diffusion is controlled only by the temperature. The poor controllability submits the unexpected diffusion occurring even during the (heating) step of rising temperature of the quartz tube. In addition, the undesirable diffusion also takes place even during the (cooling) step of decreasing the temperature. It is difficult to repeat the same profile of temperature change of the heating step, the diffusing step and the cooling step many times. Since the temperature profiles fluctuate every cycle of processes. The poor controllability leads to poor reproductivity of the diffusion depth. The diffusion depths disperse at random, in particular, in the case of shallow diffusion. Another difficulty is undesirable deposition of Zn atoms on the wafer during the cooling step. The closed tube method, therefore, is suffering from the problem of the poor controllability and the problem of the technical difficulty in the case of treating large-sized wafers. A desired diffusion method would be excellent in the controllability of diffusion and the applicability to larger wafers.
On the contrary, the open tube method is more suitable for treating large-sized wafers than the closed tube method. A larger wafer may be treated only by replacing the quartz tube by a larger tube. Since the open tube method does not seal the ends of the reaction tube, this method is immune from the technical difficulty of sealing the quartz tube. The open tube method, however, is plagued by other difficulties. The vapor pressure of the group V gas is unstable, because the group V gas and the Zn-containing gas flow in the tube. The instability of the group V gas may invite the dissociation of the V element atoms from the wafer surface. The open tube method has a more serious drawback. A great amount of the V element gas is supplied into the tube for maintaining the V gas pressure. The V element gas, for example, arsine (AsH 3 ) or phosphine (PH 3 ), is a strong poison. Protection of the environments would require a large-scaled depollution equipment of the exhaustion gas for the open tube method. The open tube method needs a highly expensive, large apparatus on an industrial scale. Thus, the semiconductor industry has not yet employed the well-known open tube method as Zn-diffusion technology.
SUMMARY OF THE INVENTION
One purpose of the present invention is to provide a Zn-diffusion method and apparatus enabling Zn to diffuse into large InP or GaAs wafers. Another purpose of the present invention is to provide an inexpensive Zn-diffusion method and apparatus without large scaled equipment. A further purpose of the present invention is to provide a Zn-diffusion method and apparatus which forbid the extra diffusion during the heating step and the cooling step. A further purpose of the present invention is to provide a Zn-diffusion method enabling to control exactly the timing of the beginning or the finishing of the Zn-diffusion by pertinent ways other than controlling the temperature. A further purpose of the present invention is to provide a Zn-diffusion method and apparatus enabling to control the density of group V element vacancies. A further purpose of the present invention is to provide a Zn-diffusion method and apparatus immune from the use of poisonous gases.
The diffusion method of the invention includes the steps of preparing a horizontal, long base plank having an exhaustion hole and a wafer-storing cavity, inserting a group III-V compound sample wafer into the cavity of the base plank, preparing a slider consisting of a frame with serially aligning M rooms with an open bottom and a rack being separated from each other by (M−1) partition walls, a non-doped capping wafer affixed at a front end of the frame and a cap plate for covering a top of the frame, taking the cap plate off the top of the slider, putting one of a Zn-diffusion source and a V element source turn by turn on each rack of the serially-aligning rooms, fixing the cap plate on the top of the frame for covering the open top of the slider, laying the slider on the base plank, affixing a manipulating bar to the slider, putting the base plank into a tube, making an inner space of the tube vacuous, carrying the slider by the manipulating bar at spots where each room lies in turn just above the exhaustion hole for evacuating each room through the exhaustion hole, carrying the slider by the manipulating bar to a spot for covering the sample wafer with the capping wafer of the slider, inserting the tube into a furnace with heaters, heating the base plank, the sample wafer and the slider, moving the slider at a spot for covering the sample wafer with the room having the diffusion source when the temperature attains to a pertinent temperature for diffusion, diffusing the Zn atoms into the sample wafer for a determined time at a pertinent temperature in the diffusion source room as a first diffusion process, moving the slider to a spot for covering the sample wafer with the room having the V element source, changing the temperature of the sample wafer to a temperature pertinent to following diffusion by regulating power of the heaters, moving the slider to a spot for covering the sample wafer with the following room having the diffusion source, diffusing the Zn atoms into the sample wafer for a determined time at a pertinent temperature in the diffusion source room as a second diffusion process, repeating necessary cycles of the steps of changing temperature and the steps of the Zn-diffusion, and finally moving the slider at a spot away from the sample wafer for cooling the sample wafer in a state separating from the diffusion room of the slider.
This invention uses a slider for diffusion of Zn unlike the prior closed tube method or the open tube method. The slider has a frame and a cap plate. The frame has an outer walls and inner partition walls. The frame contains M rooms of an open bottom and an open top separating by the (M−1) partition walls. The cap plate covers the open tops of the rooms of the frame. Each room has a rack on a side wall for holding a Zn-diffusion source or a V element source. When the slider is heated in a closed state, the rooms are filled with the vapor of the diffusion source or the vapor of the V element. Optionally, a non-doped capping wafer accompanies the slider at a front end. The slider is put upon a long, horizontal, flat base plank. The slider is equipped with a manipulating bar for sliding the slider in a longitudinal direction on the base plank.
The base plank has a cavity for storing a sample wafer to be doped with Zn and an exhaustion hole. The base plank is inserted into a tube, e.g., quartz tube, which can be made vacuous by a vacuum pump. Once the gas is evacuated out of the tube and hydrogen gas is introduced into the tube as atmosphere gas. Hydrogen gas accelerates the heating and the cooling of the tube through reinforcing the convection and the heat conduction. The tube is loaded into a preheated furnace having heaters. The heaters heat the base plank, the slider, the diffusion sources and the V element sources. The diffusion source room or the V element room in turn occupies at a spot just above the sample wafer by displacing the slider upon the base plank by the manipulating bar. When the Velement room having the V element gas occupies the wafer spot, the wafer is heated to a suitable temperature. When the wafer is heated to the temperature, the slider should be moved for coinciding the diffusion room having the Zn-diffusion source with the wafer spot for starting the diffusion.
In the diffusion room, Zn is diffused into the wafer in vapor phase, since the diffusion room in the slider is full of the diffusion source gas. When the vapor phase diffusion finishes, the diffusion room is separated from the sample wafer by displacing the slider by the manipulating bar. In the case of multiple diffusion for diffusing Zn to the same wafer more than once at different temperatures, the wafer should be held in the Velement room or under the capping wafer for changing the temperature of the wafer under the V element pressure. When the temperature attains to the determined temperature, the slider is moved for coinciding the sample wafer with the next diffusion room. Alternatively, the bottom of the V element room can be closed by a non-doped wafer. The sample wafer should be separated from the diffusion room of the slider during the step of cooling for preventing the extra diffusion.
The sample wafer is protected by the Velement room or the non-doped capping wafer during the step of changing the temperature of the wafer, for example, heating or cooling. M denotes the number of the rooms of the slider. M rooms have an opening bottom and an opening top. There are two kinds of sliders. One kind has a capping wafer either in front of or at the back of the frame. The other kind has no capping wafer. The capping wafer plays a similar role to the V element room for protecting the wafer from losing the V element.
In the case of the non-capping wafer, the room number M is two or more than two (M≧2), since the slider must contain at least one V element room and at least one diffusion room. K-time diffusion requires K diffusion rooms and K V element rooms which align in turn. Thus, M=2K for the K-time diffusion. In addition, a cooling room having V element can accompany the slider. In the case, the slider includes (K+1) Velement rooms and K diffusion rooms.
In the case of the front capping wafer, the room number M is one or more than one (M≧1), since the front capping wafer plays a similar role of the V element room. K-time diffusion requires (K−1) V element rooms and K diffusion rooms. Then, M=2K−1 for the K-time diffusion. If a cooling room is additionally equipped, the room number is M=2K. Some of the V element rooms can be replaced by capping wafer, since the roles of them are similar.
There are several variations even for a determined time of diffusion. For example, a K time diffusion contains the following six Versions;
Version 1. A capping wafer+(2K−1) room slider
Version 2. 2K room slider
Version 3. A capping wafer+2K room slider
Version 4. (2K+1) room slider
Version 5. A capping wafer+(2K−1) room slider+a capping wafer
Version 6. 2K room slider+capping wafer
Versions 1,3 and 5 enclose an object wafer with a capping wafer during the heating process for preventing the V element from escaping. Versions 2, 4 and 6 enclose an object wafer with a V element room for preventing the V element from escaping. The difference relates to the rising temperature process (heating process).
The cooling step gives different versions. Versions 1 and 2 cool the wafer in hydrogen atmosphere in the tube, because the wafer is not protected at the cooling step. All the embodiments that will be explained later belong to Versions 1 or 2. Version 1 gives the slider an array of diffusion room+V element room+diffusion room+ . . . +diffusion room (M=2K−1). Version 2 gives the slider another array of V element room+diffusion room+ . . . +diffusion room+V element room+diffusion room (M=2K).
Versions 3 and 4 protect the object wafer by the last V element room during the cooling step for avoiding the dissociation of the V element. The slider of Version 3 has an array of diffusion room+V element room+diffusion room+ . . . +diffusion room+V element room (M=2K). The slider of Version 4 has an array of V element room+diffusion room+ . . . +diffusion room+V element room (M=2K+1).
Versions 5 and 6 protect the object wafer by the additional end capping wafer during the cooling step for avoiding the dissociation of the V element. The slider of Version 5 has an array of diffusion room+V element room+diffusion room+ . . . +diffusion room (M=2K−1). The slider of Version 6 has an array of V element room+diffusion room+ . . . +diffusion room (M=2K).
The base plank is a long smooth even plank allowing the slider to slide without friction but preventing vapor from leaking through the gap between the base plank and the slider. Evenness, flatness, refractory and lubricancy are essential to the base plank. The base plank can be made from, for example, carbon. Carbon excels in heat resistance and lubricancy. Sliding on carbon may yield carbon dust. Thus, the carbon should be coated with amorphous carbon (a-C) or silicon carbide (SiC). It is possible to fix a carbon capping plate upon a carbon frame with carbon screws.
The Zn diffusion material should be solid at room temperature and should sublime at high temperature without melting. The candidates of the diffusion material are Zn 3 P 2 , ZnP 2 , Zn 3 P 2 +P(red phosphorus), ZnP 2 +P(red phosphorus). The V element material is the V component of the object wafer. The V element material is P for an InP wafer and As for a GaAs wafer.
This invention has big advantages. Unlike the closed tube method, this invention allows Zn compounds to diffuse into large sized wafers. The large size brings about no difficulty in the present invention. This invention treats with large sized wafers by enlarging the diffusion rooms and the V element rooms in the slider. This invention can easily be applied to a wafer larger than 2 inch in diameter. This invention is superior to the closed tube method in the applicability to large sized wafers. Extra diffusion does not occur at the heating step and at the cooling step, since the wafer is separated from the diffusion source. The displacement of the slider gives desired diffusion density distribution to the wafer. This invention enhances the controllability of the dopant distribution in the direction of thickness. This invention is immune from the problem of dopant deposition on the wafer surface at the cooling step, since the wafer is isolated from the dopant(Zn compound). The inner space of the diffusion room is so small and narrow that this invention dispenses with a large volume of V element gas flow. A reduction of poisonous V element gas improves the safety. This invention is superior to the open tube method in the gas consumption, the freedom of the dopant deposition and the safety.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 ( 1 ) is a sectional view of Embodiment 1 of a slider having a single diffusion room at the step of vacuuming the diffusion room.
FIG. 1 ( 2 ) is a sectional view of Embodiment 1 at the step of heating the apparatus and an object wafer.
FIG. 1 ( 3 ) is a sectional view of Embodiment 1 at the step of diffusing impurity into the object wafer.
FIG. 1 ( 4 ) is a sectional view of Embodiment 1 at the step of cooling the apparatus.
FIG. 2 is a plan view of the slider of Embodiment 1 in an open state without the cap.
FIG. 3 is a plan view of the slider of Embodiment 1 in a closed state with the cap.
FIG. 4 is a graph of the time dependence on the temperature of the diffusion room in Embodiment 1.
FIG. 5 is a sectional view of the slider, the base plank, the quartz tube and the reaction furnace of Embodiment 1.
FIG. 6 is a graph showing the relation between the diffusion depth and the root square of diffusion time at 580° C. on non-doped InP wafers and Sn-doped InP wafers.
FIG. 7 ( 1 ) is a sectional view of Embodiment 2 of a slider having a diffusion room and a V-element room at the step of vacuuming the V-element room(red phosphorus room).
FIG. 7 ( 2 ) is a sectional view of Embodiment 2 at the step of vacuuming the diffusion room.
FIG. 7 ( 3 ) is a sectional view of Embodiment 2 at the step of heating the apparatus and an object wafer.
FIG. 7 ( 4 ) is a sectional view of Embodiment 2 at the step of diffusing impurity into the object wafer.
FIG. 7 ( 5 ) is a sectional view of Embodiment 2 at the step of cooling the apparatus.
FIG. 8 is a plan view of the slider of Embodiment 2 having the V-element room and the diffusion room in an open state without the cap.
FIG. 9 is a plan view of the slider of Embodiment 2 in a closed state with the cap.
FIG. 10 is a graph showing the time dependence on the temperature in Embodiment 2 having a V element room instead of the capping wafer.
FIG. 11 is a section of a three-room slider for twice diffusion of Embodiment 3.
FIG. 12 is a plan view of the three-room slider without the cap for twice diffusion of Embodiment 3.
FIG. 13 is the time dependence of the temperature for twice diffusion of Embodiment 3.
FIG. 14 is a section of an impurity diffusion apparatus of a closed tube method.
FIG. 15 is a section of an impurity diffusion apparatus of the closed tube method disclosed by Japanese Patent Publication No.2-24369.
FIG. 16 is a section of an impurity diffusion apparatus of the open tube method disclosed by Japanese Patent Laying Open No.62-143421.
FIG. 17 is a section of a three-room slider for twice diffusion of Embodiment 3 which employs a capping wafer instead of the V element room.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[Embodiment 1: single room type slider; rough capping wafer; single time diffusion]
Embodiment 1 relates to single time diffusion, employing a non-doped capping wafer with a rough surface. Embodiment 1 covers an object wafer in the cavity by the non-doped capping wafer for protecting the object wafer against the dissociation of V element during the heating step (rising temperature step), moves the slider above the object wafer when the wafer attains to the diffusion temperature Td, starts the Zn diffusion into the object wafer and separates the slider from the object wafer when the diffusion finishes for isolating the object wafer from the diffusion vapor atmosphere.
FIG. 1, FIG. 2 and FIG. 3 denote Embodiment 1. FIG. 1 shows the steps of the Zn diffusion of the present invention. FIG. 2 is a plan view of a frame and a capping wafer. FIG. 3 is a plan view of a slider and the capping wafer. This is a device for a single wafer. A double-sized slider for treating two wafers can be produced by enlarging the width twice in the lateral direction. Furthermore, a slider including m wafers can be made instead of the single wafer slider of FIG. 2 and FIG. 3 . The pertinent size of the frame of the slider can be determined by considering the required throughput.
The parts shown by FIG. 1 are contained in a reaction chamber, for example, a quartz tube 20 , as shown in FIG. 5 . The reaction chamber can be evacuated. A base plank 1 is a long smooth even carbon table elongating in a longitudinal direction. The base plank 1 is inserted into the reaction chamber. The carbon base plank 1 has a good resistance against chemicals and good sliding performance. Naked carbon may appear on the surface of the base plank 1 . It is preferable to coat at least the upper surface of the base plank 1 by some hard material for preventing the base plank 1 from inducing carbon powder by friction. The base plank 1 may be coated with, for example, silicon carbide (SiC) or amorphous carbon (a-C). The base plank 1 can otherwise be made from refractory metal, for instance, tantalum (Ta), tungsten (W) or stainless steel. A shallow wafer-storing cavity 2 is perforated on the base plank 1 for maintaining an object wafer 14 . The size of the cavity 2 is determined by the object wafer 14 . An exhaustion hole 3 is pierced vertically in the base plank 1 .
An important part is a slider 4 . The slider 4 has a top wall and side walls with a bottom open. The slider 4 has a rectangular frame 5 and a capping plate 6 . FIG. 2 shows only the frame 5 . FIG. 3 denotes the slider 4 with the cap plate 6 . In the example, the inner space within the slider 4 has a 30 mm width, a 30 mm length and a 20 mm height with a volume of 18 cm 3 . The slider 4 is put on the base plank 1 with the open bottom down. When the open bottom coincides with the exhaustion hole 3 , a vacuum is formed in the inner space of the slider 4 by absorbing gases from the exhaustion hole 3 . The cap plate 6 is fixed upon the rectangular frame 5 by screws 7 .
The open bottom of the frame 5 slides on the base plank 1 , keeping a direct contact therewith. The smooth and flat bottom brings the slider 4 into tight contact with the base plank 1 without leak. The frame 5 is made from, e.g. carbon which allows exact processing within a tolerance of several microns. The side walls of the slider 4 have a thickness between 10 mm and 20 mm. The cap plate 6 can be made from carbon. Preferably, the carbon frame 5 and the cap plate 6 should be coated with SiC or a-C like the base plank 1 .
A hole 8 is perforated on the cap plate 6 and the frame 5 for inserting an L-shaped end of a manipulating bar 9 . The slider 4 is moved forward or backward by the manipulating bar 9 on the base plank 1 . Conventional liquid phase epitaxy (LPE) is used to move a slider by a manipulating bar on a base plank. It is also analogy from the conventional LPE to make the slider from carbon. But in fact, the slider or the cap plate can be made from stainless steel or other metals.
The frame 5 , the cap plate 6 and the base plank 1 form a diffusion room 10 . The diffusion room 10 is a small, movable space. The movability of the slider 4 is an origin of the excellent controllability of the present invention. The diffusion room 10 has a rack 12 on the side wall for storing a diffusion material 11 . The diffusion material depends upon the object wafer. In the case of an InP wafer, the diffusion material should be a compound of Zn and P, for example, Zn 3 P 2 or ZnP 2 . In the case of a GaAs wafer, the diffusion material should be a compound of Zn and As, for example, Zn 3 As 2 or ZnAs 2 . In general, the diffusion material should be a sublimable compound including Zn and the V element of the object wafer. The rack 12 sustains a solid diffusion material. When the diffusion room 10 is heated, the diffusion room 10 is full of the vapor of the material. The tight contact of the slider 4 on the base plank 1 prevents the vapor of the material from leaking outward.
The diffusion material 11 is loaded in the slider 4 by taking the cap plate 6 off the frame 5 , supplying a solid diffusion material 11 on the rack 12 , laying the cap plate 6 upon the frame 5 , fixing the cap plate 6 on the frame 5 by the screws 7 . Then, the L-end of the manipulating bar 9 is inserted into the hole 8 .
The slider 4 has a non-doped capping wafer 13 at the front end. The non-doped capping wafer 13 has a rough surface facing to an object wafer for enhancing the function of suppressing dissociation of the V element of the object wafer. The capping wafer 13 moves together with the slider 4 on the base plank 1 , since the capping wafer 13 is stuck to the slider 4 . The material of the capping wafer 13 has the same material as the object wafer. An InP capping wafer should be employed for an InP object wafer. A GaAs object wafer requires a GaAs capping wafer. The capping wafer 13 plays the role of covering the object wafer 14 during the heating step for inhibiting the V element from escaping the object wafer 14 . In general, III-V compound semiconductors, e.g., InP and GaAs, should be suppressed at high temperatures by V element vapor pressure, since the V element has a big dissociation pressure. When the object wafer 14 is heated in the cavity 2 , the capping wafer is simultaneously heated on the base plank 1 . The capping wafer 13 discharges the V element gas from the ragged surface for filling the narrow space within the cavity 2 with e.g., As-gas or P-gas. The capping wafer 13 suppresses the dissociation of the V element from the object wafer 14 .
The capping wafer 13 should be a non-doped wafer. Otherwise impurities would be transferred from the capping wafer 13 to the object wafer 14 . The surface facing the object wafer 14 is not polished but roughened. The roughed surface enhances the discharge of the V element gas from the capping wafer 14 by enlarging the effective area of the surface. The narrow space within the cavity 2 and the capping wafer 14 is occupied by the V element vapor. A tip of a thermocouple 15 is in contact with the base plank 1 beneath the object wafer 14 .
The following steps shown in FIG. 1 will be done according to the temperature change of FIG. 4 for doping Zn into the object wafer.
[Preparatory steps]
(1) An object wafer 14 , e.g., InP wafer or GaAs wafer, is put into the wafer-storing cavity 2 of the base plank 1 .
(2) The quartz tube 20 is inserted into the pre-heated furnace.
(3) The slider 4 is pulled backward on the base plank 1 to a preparing point and the non-doped capping wafer 13 is affixed at the front of the slider.
(4) The screws 7 are taken out of the cap plate 6 and the slider 4 . The slider 4 is opened by eliminating the cap plate 6 . A diffusion material solid 11 is supplied on the rack 12 . The diffusion material 11 is Znp 2 , Zn 3 P 2 in the case of an InP object wafer. The diffulsion material is ZnAs 2 , Zn 3 As 2 or so in the case of a GaAs object wafer.
(5) The cap plate 6 is put upon the frame 5 . The cap plate is fixed to the frame 5 by turning on the screws 7 . The L-end of the manipulating bar 9 is put into the hole 8 of the slider 4 .
(6) The base plank 1 with the slider 4 is inserted into the quartz tube 20 (FIG. 5 ).
[Step 1 (forming a vacuum in the diffusion room of the slider]
(7) A vacuum is formed in the reaction tube 20 in the state of FIG. 1 ( 1 ) by a vacuum pump. The outer space of the slider 4 is evacuated by the vacuum pump. The inner space of the slider 4 is also evacuated through the exhaustion hole 3 of the base plank 1 . A desired vacuum of the same pressure is created in both the outer space and the inner space.
(8) The slider 4 is pushed forward by the manipulating bar 9 to a position where the diffusion room 10 deviates from the exhaustion hole 3 and the capping wafer 13 covers the object wafer 14 for isolating the inner space of the slider 4 from the outer space. After the tube is evacuated to a vacuum, hydrogen gas is introduced into the reaction tube for accelerating heat conduction or heat convection for facilitating heating and cooling. The temperature in the diffusion room is denoted by the line αβ in FIG. 4 .
[Step 2 (rising temperature step or heating step)]
(9) The base plank 1 , the capping wafer 13 and the object wafer 14 are heated by the furnace at the heating step, where the temperature rises toward the diffusion temperature Td, as shown by the curve βγ in FIG. 4 . The capping wafer 13 discharges the V element gas from the ragged surface for preventing the object wafer 14 from losing the V element atoms at the heating step. The protection by the capping wafer 13 may allows weak occurrence of the V element vacancies. The heating step is shown in FIG. 1 ( 2 ).
(10) The slider 4 is also heated at the heating step for inducing the diffusion material 11 to sublime and to fill the inner space of the slider 4 . The vapor pressure of the V element material rises in the diffusion room 10 . No diffusion occurs at the heating step, since the object wafer 14 is separated from the Zn vapor. The temperature of the wafer 14 is observed by the thermocouple 15 .
[Step 3 (diffusion step)]
(11) When the temperature attains to the diffusion temperature Td (T=Td), the slider 4 is pushed forward by the manipulating bar 9 at a spot, where the diffusion room 10 lies above the wafer-storing cavity 2 , as shown in FIG. 1 ( 3 ). This state corresponds to the line γδ on the temperature profile of FIG. 4 . The diffusion room 10 of the slider 4 has been filled with dense Zn compound vapor. The Zn compound vapor comes into contact with the object wafer 14 . Immediately, the Zn diffusion into the wafer 14 starts. Since the diffusion room 10 is narrow, there is no macroscopic flow of gas. The V element vapor is stable in the diffusion room 10 . The desired diffusion depth determines the diffusion time tc.
[Step 4 (cooling step)]
(12) When the predetermined diffusion time has passed, the slider 4 is moved on the base plank 1 by the manipulating bar 9 for separating the slider 4 from the object wafer 14 . The Zn diffusion stops at once.
(13) The wafer 14 is cooled in a state separated from the slider 4 , as shown in FIG. 1 ( 4 ). This step corresponds to the line δε in FIG. 4 .
FIG. 5 shows the section of the diffusion apparatus including the surroundings. The base plank 1 , the slider 4 and the manipulating bar 9 are contained in the quartz tube 20 . The quartz tube 20 is not a closed tube. The tube 20 can be evacuated from an end. The tube 20 allows the operation of the manipulating bar 9 from the outer space. The whole of the tube 20 is inserted into a furnace (heater) 21 The heater 21 consists of a coil resistor 23 and a refractory material 22 supporting the coil resistor 23 . The furnace 21 is an ordinary electric heater which generates Joule's heat by the supply of electric current.
[Embodiment 2: two room type slider; V element room; single time diffusion]
Embodiment 2 aims at preventing the V element from dissociating out of the object wafer during the heating process more effectively than Embodiment 1. For the purpose, Embodiment 2 employs a V element room in the slider 4 instead of the non-doped capping wafer of Embodiment 1. The object wafer is enclosed with higher V element vapor pressure due to the V element room during the heating step than in Embodiment 1. The role of the newly introduced V element room is similar to the capping wafer. When the temperature is raised to Td, the slider is displaced to a spot where the diffusion room coincides with the object wafer for starting the Zn diffusion. When the Zn diffusion finishes, the slider is again displaced for separating the wafer from the Zn atmosphere. Embodiment 2 can suppress the dissociation of the V element by the high V element vapor pressure. Embodiment 2 is more effective for inhibiting the occurrence of V element vacancies in the object wafer.
FIG. 7 shows the steps of the Zn diffusion of Embodiment 2. FIG. 8 is a plan view of the frame of the slider of Embodiment 2. FIG. 9 is a plan view of the slider with the cap plate. A slider 24 has two rooms unlike Embodiment 1. A V element room 30 is newly furnished to the slider 24 instead of the capping wafer. The slider 24 has a frame 25 and a capping plate 26 . The frame 25 has external walls and a partition 28 in the middle. The frame 25 is divided into the V element room 30 and a diffusion room 10 . The rear diffusion room 10 has a rack 34 on the wall for keeping a diffusion material 11 .
The front V element room 30 has a rack 32 on the wall for maintaining a V element solid 31 , which is phosphorus (P) for an InP wafer or is arsenic (As) for a GaAs wafer. The two room type slider 24 covers the object wafer 14 with the V element room 30 during the heating step for suppressing the generation of V element vacancies. The steps of FIG. 7 are explained. FIG. 10 is the temperature profile of the steps measured by a thermocouple 15 .
[Preparatory steps]
(1) An object wafer 14 , e.g., an InP wafer or a GaAs wafer, is inserted into a wafer-storing cavity 2 of a base plank 1 .
(2) The reaction tube is inserted into the furnace.
(3) The slider 24 is moved to a spot where the V element room 30 coincides with a exhaustion hole 3 of the base plank 1 .
(4) Screws 27 are gotten off and the capping plate 26 is removed from the frame 25 . A diffusion material 11 is supplied to the rack 34 of the rear diffusion room 10 . The diffusion material 11 is Znp 2 or Zn 3 P 2 for an InP wafer, or ZnAs 2 or Zn 3 As 2 for a GaAs wafer. A V element material 31 is put on the rack 32 of the former V element room 30 . The V element material is red phosphorus (P) for the InP wafer, or arsenic (As) for the GaAs wafer. The following describes an example of employing red phosphorus for an InP wafer as the V element material 31 .
(5) The capping plate 26 is put upon the frame 25 and fixed to the frame 25 by the screws 27 . The L-shaped end of a manipulating bar 29 is put into a hole 33 of the slider 24 .
(6) The whole of the base plank 1 with the slider 24 is inserted into the quartz reaction tube 20 (FIG. 5 ).
[Step 1 (exhausting the V element room (red phosphorus room) into vacuum]
(7) The slider 24 stays at the spot where the red phosphorus (V element) room 30 lies above the exhaustion hole 3 , as shown in FIG. 7 ( 1 ). A vacuum is created in the reaction tube by a vacuum pump (not shown). The outside of the slider 24 is evacuated directly. The red phosphorus room 30 of the slider 24 is also evacuated through the exhaustion hole 3 . This step corresponds with the temperature line ζη (room temperature) in FIG. 10 .
[Step 2 (exhausting the diffusion room)]
(8) The slider 24 is pushed forward by the manipulating bar 29 to a spot where the diffusion room 10 lies above the exhaustion hole 3 , as shown in FIG. 7 ( 2 ). A vacuum is created in the diffusion room 10 through the exhaustion hole 3 . Thus, both the phosphorus room 30 and the diffusion room 10 are vacuous. Hydrogen gas is introduced into the reaction tube 20 . The outer space is occupied by hydrogen gas. The temperature takes the line ηθ (room temperature) in this step as shown in FIG. 10 .
[Step 3 (heating step or rising temperature step)]
(9) When a vacuum is created in the diffusion room 10 , the slider 24 is pushed forward to a spot where the V element room 30 covers the object wafer 14 which is shown by FIG. 7 ( 3 ). This corresponds to the point θ in the temperature profile of FIG. 10 .
(10) At the step 3 of rising temperature, the furnace overall heats the object wafer 14 , the slider 24 , the V element material 31 and the diffusion material 11 , which is denoted by the curve θι. The dopant (Zn compound) material 11 is sublimed for making high Zn compound vapor pressure in the diffusion room 10 . The V element material 31 is sublimed for creating high V element vapor pressure in they element room 30 . The object wafer 14 , which is protected by the high V element vapor pressure in the V element room, is immune from the dissociation of the V element out of the surface. As the temperature rises from θ to ι, the V element (phosphorus here) vapor pressure in the V element room 30 and the Zn compound vapor in the diffusion room 10 pressure rise.
[Step 4 (diffusion step)]
(11) When the temperature T rises to Td, the slider 24 is moved forward by the manipulating bar 29 at a spot where the diffusion room 10 covers the wafer 14 , as shown in FIG. 7 ( 4 ). The dopant vapor pressure has risen enough high at Td in the diffusion room 10 . The Zn vapor comes into contact to the wafer 14 . The Zn diffusion starts immediately on the object wafer 14 . The diffusion step corresponds to the line ικ in FIG. 10 . The diffusion time tc should be determined by the purpose of the diffusion.
[Step 5 (cooling step)]
(12) When the diffusion time tc has passed, the slider 24 is moved to a spot (FIG. 7 ( 5 )) for separating the diffusion room 10 from the cavity 2 by the manipulating bar 29 . This corresponds to the point κ in FIG. 10 . The diffusion stops at once.
(13) The wafer 14 is cooled from Td to room temperature which is denoted by the line κλ in FIG. 10 .
[Embodiment 3: three room type slider; twice diffusion]
Embodiment 3 aims at diffusing Zn twice into an object wafer on different conditions. The twice diffusion requires three rooms for the slider. The doping processes are different in the kind of the dopants or in the diffusion temperature. Two rooms of the three are diffusion rooms containing Zn compounds. The two diffusion rooms sandwich a V element room. The slider has the diffusion room, the V element room and the diffusion room in turn. An additional capping wafer protects an object wafer during the heating step. The V element room seals the object wafer in the intermediate step between the first (former) diffusion and the second (latter) diffusion. Embodiment 3 employs different means for inhibiting the object wafer from losing the V element. Twice diffusion is realized by Embodiment 3.
But this invention can also be applied to three-time-diffusion or four-time-diffusion which are different in conditions of e.g., different dopants, different times or different temperatures. In general, M-times of diffusion requires 2M rooms (M diffusion rooms and M V element rooms) or (2M−1) rooms (M diffusion rooms and (M−1) V element rooms with a capping wafer).
FIG. 11 shows the sectional view of a slider of Embodiment 3. FIG. 12 is a plan view of the slider without the cap plate. The V element vapor of FIG. 11 can be replaced by a non-doped capping wafer. FIG. 17 shows a version having a bottom capping wafer 57 in the V element room 30 . Detailed steps are not shown in figures, because the steps are obvious from FIG. 1 of Embodiment 1 and FIG. 7 of Embodiment 2. A slider 44 has three rooms formed by a frame 45 and a capping plate 46 . The frame 45 has external walls and two partition walls 52 and 53 . The three rooms are a diffusion room 50 , a V element room 30 and a diffusion room 10 in this order. The capping plate 46 is fixed upon the frame 45 by screws 47 . The rooms 50 , 30 and 10 have open bottoms. The first diffusion room 50 has a rack 56 containing a first diffusion material 51 . The V element room 30 has a rack 55 for storing a V element material 31 . The second diffusion room 10 has a rack 54 for sustaining a second diffusion material 11 . The slider 44 has an end hole 48 for fitting a manipulating bar 49 . The manipulating bar 49 displaces the slider 44 in the longitudinal direction upon a base plank 1 .
The slider 44 has a non-doped capping wafer 13 fixed at the front end. The non-doped capping wafer 13 covers the cavity 2 for suppressing the V element from escaping out of the surface of an object wafer 14 at the heating step. The capping wafer 13 can also be replaced by a V element room in the slider. In the variation, the slider would have four rooms.
FIG. 13 denotes the temperature profile of the double diffusion of Embodiment 3.
Individual steps are explained;
[Preparatory steps]
(1) An object wafer 14 is put in the cavity 2 on the base plank 1 .
(2) The reaction tube (e.g., quartz tube) is installed into the furnace.
(3) The slider 44 is pulled back to a point where the first diffusion room 50 stays above the exhaustion hole 3 by the manipulating bar 49 .
(4) The screws 47 are taken off the slider 44 . The cap plate 46 is removed from the frame 45 . A second diffusion material 11 is supplied on the rack 54 in the second diffusion room 10 . A V element material 31 is put on the rack 55 in the middle V element room 30 . Like former embodiments, the V element material is red phosphorus for an InP object wafer or arsenic (As) for a GaAs object wafer. A first diffusion material 51 is laid on the rack 56 of the first diffusion room 50 .
(5) The capping plate 46 is fixed upon the frame 45 by the screws 47 . The end of the manipulating bar 49 is inserted into the end hole 48 of the slider 44 .
(6) The whole of the base plank 1 is inserted into the quartz tube 20 .
[Step 1 (exhaustion of first diffusion room·V element room·second diffusion room)]
(7) The whole reaction tube is exhausted into a vacuum. The outer space of the slider 44 is evacuated. A vacuum is created also in the first diffusion room 50 through the exhaustion hole 3 .
(8) The slider 44 is pushed forward to a spot where the V element room 30 lies upon the exhaustion hole 3 . The V element room 30 is exhausted through the exhaustion hole 3 .
(9) The slider 44 is further pushed forward to another spot where the second diffusion room 50 lies upon the exhaustion hole 3 . The second diffusion room 50 is evacuated through the exhaustion hole 3 . Thus, all the rooms 50 , 30 and 10 are evacuated into a vacuum. The slider 44 is slightly displaced for isolating the diffusion room 10 from the atmosphere in the reaction tube 20 . Three rooms 50 , 30 and 10 are isolated. Hydrogen gas is supplied into the reaction tube, which corresponds to the line μν in FIG. 13 .
[Step 2 (step of rising temperature or heating step)]
(10) The slider 44 is carried by the manipulating bar 49 to a spot where the non-doped capping wafer 13 shields the object wafer 14 which is shown in FIG. 11 . The furnace heats the whole of the reaction tube including the base plank, the slider 44 and the wafers 14 and 13 . This corresponds to the curve νξ in FIG. 13 . The capping wafer 13 protects the wafer 14 during the rising temperature step.
[Step 3 (first diffusion step)]
(11) When the temperature rises up to Td (T=Td), the manipulating bar 49 conveys the slider 44 to a spot where the wafer 14 is covered by the first diffusion room 50 which has high vapor pressure of the Zn compound. The wafer 14 adsorbs the dopants (the Zn compound). Zn atoms diffuse from the surface into the object wafer. The diffusion corresponds to the line ξο in FIG. 13 . The diffusion time t 1 is predetermined in accordance with the purpose.
[Step 4 (transient cooling)]
(12) When the predetermined diffusion time t 1 has elapsed, the slider 44 is further moved to a spot where the V element room 30 shields the object wafer 14 . The temperature is decreased from Td 1 to Td 2 by reducing the heater power. The transitory cooling is denoted by the line οπ in FIG. 13 . At the transitional step between Td 1 to Td 2 , the V element vapor pressure protects the wafer 14 from the degeneration due to the V element dissociation in the V element room 30 .
[Step 5 (second diffusion step)]
When the temperature falls to Td 2 , the slider 44 is moved forward to a spot where the wafer lies under the second diffusion room 10 . The high dopant vapor pressure begins the second diffusion immediately in the second diffusion room 10 . The Zn diffusion lasts for t 2 . The diffusion corresponds to the line πρ in FIG. 13 .
[Step 6 (cooling step)]
(14) When t 2 elapses, the slider 44 is separated from the cavity 2 by the manipulating bar 49 . The diffusion stops at once. The temperature of the furnace is decreased along the line ρσ in the temperature profile of FIG. 13 .
Embodiment 1 is further explained in more detail. The Zn diffusion is carried out by the slider of M=1 which is shown in FIG. 1, FIG. 2 and FIG. 3 . Since M=1, the slider has only the single room 10 . The inner space of the slider 4 has a 30 mm width, a 30 mm length and a 20 mm height. The volume of the inner space is 18 cm 3 . A non-doped InP capping wafer 13 with an inner rugged surface is fitted at the front end of the slider 4 . Zn 3 P 2 (4 mg) is put on the rack 12 of the diffusion room 10 . Two different InP wafers {circle around (1)} and {circle around (2)} are allotted for object wafers for surveying the influence of the carrier density.
InP wafer {circle around (1)} . . . Sn doped InP (carrier density: 1×10 18 cm −3 )
InP wafer {circle around (2)} . . . non-doped InP (carrier density: 5×10 15 cm −3 )
An object wafer is put into the cavity 2 . The frame 5 is put on the base plank 1 . The capping plate 6 is fixed to the frame 5 by the screws 7 . The end of the manipulating bar 9 is coupled into the hole 8 of the slider 4 . The base plank 1 is inserted into the quartz tube. The quartz tube is exhausted into a vacuum of 1×10 −6 Torr. The slider 4 is carried for coinciding the diffusion room 10 with the exhaustion hole 3 . A vacuum is created in the diffusion room 10 . Hydrogen gas with good heat conduction is introduced into the quartz tube. The quartz tube is installed into the furnace.
The furnace heats the base plank 1 , the slider 4 , the wafer 14 and so on. The temperature of the object wafer 14 is monitored by the thermocouple 15 . When the temperature measured by the thermocouple is stable at 580° C., the slider 4 is pushed forward for sending the diffusion room 10 just above the object wafer 14 . The displacement brings the wafer into contact with the Zn 3 P 2 vapor. Zn atoms are diffused into the object wafer 14 at 580° C. for the determined diffusion time. When the predetermined diffusion time has elapsed, the slider is separated from the wafer 14 by the manipulating bar 9 . The diffusion finishes without delay. The wafer 14 is cooled in the state isolated from the diffusion room 10 . The present invention is far superior to the closed tube method in the controllability.
The base plank 1 is plucked out from the quartz tube. The object wafer 14 is taken out of the wafer-storing cavity 2 . The object wafer is cleaved for revealing the sectional sides. Then, the wafer is etched by an etchant of potassium ferrocyanide (K 4 [Fe(CN) 6 ])+potassium hydroxide (KOH) which has different etching speeds for n-type InP and p-type InP. The diffusion depth is measured by observing the etched sides of the wafer by a microscope.
The diffusion depth is determined by the average length of the Zn invading into the InP crystal. However, the initial electron density is different for various n-type InP crystals. The measured diffusion length depends upon the initial electron density of the n-type InP. The density of Zn atom varies slowly in the direction of thickness. It is difficult to determine the limit of the Zn distribution as the diffusion depth. Then, the line which equalizes the electron density n to the hole density p is defined as a pn-junction. The diffusion depth is defined as the length from the surface to the pn-junction (p=n). If the initial electron density is lower, comparatively lower doping of Zn can make a deeper pn-junction (p=n). If the initial electron density is higher, the same dopant density makes a shallower pn-junction.
Since the InP wafer {circle around (1)} having higher initial electron density of n=10 18 cm −3 the pn-junction is defined as the line on which the Zn density is equal to 10 18 cm −3 (p=n).
The wafer {circle around (2)} having lower initial electron density of n=5×10 15 cm −3 , since it is not doped with n-type dopant intentionally. The pn-junction is the interface on which the hole density is equal to 5×10 15 cm −3 . The diffusion depth is determined as the depth of the pn-junction.
The diffusion depth is measured for different diffusion times for both the wafers {circle around (2)} and {circle around (2)}. FIG. 6 shows the result of the measurement of the diffusion depth. The abscissa is the root of the diffusion time. The ordinate is the measured diffusion depth (μm). Black rounds denote the diffusion depths of the non-doped InP wafer {circle around (2)}. 4 minute diffusion gives about 5 μm of diffusion depth. 10 minutes of diffusion make about an 8 μm diffusion depth. A 10 μm diffusion depth takes about 18 minutes for the non-doped wafer {circle around (2)}. The diffusion depth is in proportion to the root of the diffusion time. Black triangles denote the diffusion depths for the Sn-doped n-InP wafer {circle around (1)} with higher initial electron density. 5 minutes of diffision give a 1.8 μm diffusion depth. 10 minute diffusion makes a 2.3 μm diffusion depth. 28 minute diffusion obtains a 4.2 μm depth. The diffusion depth is in proportion to the root of the diffusion time also for the highly doped InP wafer {circle around (1)}. The result shows that the diffusion time exactly controls the diffusion depth. In this invention, the wafer comes into contact to the Zn compound vapor at the beginning of the diffusion step and the wafer is separated from the Zn compound vapor at the cooling step by the operation of the slider. No extra diffusion occurs at the heating step and the cooling step. The control of the start and the stop of diffusion is far more rigorous in the present invention than the closed tube method. The examples use 1-inch diameter wafers. This invention can also apply to wafers of arbitrary sizes.
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An LPE (Liquid Phase Epitaxy) apparatus is diverted to a Zn-diffusion apparatus for diffusing Zn into III-V group compound semiconductor. The Zn-diffusion apparatus comprises a base plank extending in a direction, having a wafer-storing cavity for storing an object wafer and an exhaustion hole for exhaling gases, a slider having a frame and a cap plate for attaching to or detaching from the frame, the frame having serially aligning M rooms with an open bottom and a rack being separated from each other by (M−1) partition walls, a manipulating bar for sliding the slider upon the base plank forward or backward in the direction, a tube for enclosing the base plank and the slider and for being capable of being made vacuous, a heater surrounding the tube for heating the slider, each rack of the rooms being allocated with a Zn-diffusion material and a V element material (or a non-doped capping wafer) in turn for aligning the rooms into repetitions of a V element room and a diffusion room. The V element room or the capping wafer covers and protects the object wafer during the heating step. During the diffusion step, the diffusion room covers the object wafer for diffusing Zn into the wafer.
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BACKGROUND
[0001] It is well known that the property of sizing, as applied to paper, refers to a fibrous substrate's ability to resist wetting or penetration of a liquid into a paper sheet. Aqueous dispersions of alkenylsuccinic anhydride cellulose-reactive sizing agent have been widely used in the paper and board making industry for many years, for sizing a wide variety of grades which include printing and writing grades and bleached and unbleached board grades. Cellulose-reactive alkenylsuccinic anhydride imparts hydrophobic properties to, the paper and board products.
[0002] Chemicals used to achieve sizing properties are known as either internal sizes or surface sizes. Internal sizes can be either rosin-based or synthetic sizes such as alkenylsuccinic anhydride, or other materials. Internal sizes are added to the paper pulp prior to sheet formation. Surface sizes are sizing agents that are added after the paper sheet has formed, most generally at the size press, although spraying applications may also be used.
[0003] Alkenylsuccinic anhydride sizing agent is ordinarily applied by dispersing it in a cationic or amphoteric hydrophilic substance such as a starch or a polymer. The starch or polymer-dispersed alkenylsuccinic anhydride sizing emulsion is added to the pulp slurry before the formation of a paper web. This type of addition of alkenylsuccinic anhydride sizing emulsions to the papermaking system is commonly called wet-end addition or internal addition of alkenylsuccinic anhydride.
[0004] Application of wet end applied cellulose reactive sizing agents such as alkenyl succinic anhydride using traditional emulsification methods has the following disadvantages: ASA emulsification in cationic starch needs a high starch/size ratio for emulsification. Also, in addition to the foregoing problem, the starch needs to be an high quality starch suitable for producing a stable, high quality ASA emulsion. ASA emulsification in cationic polymer or starch-grafted polymer also uses a lower polymer/size ratio than for starch, but a polymer that provides a stable, high quality ASA emulsion is needed for emulsification. Also the traditional emulsification of ASA in starch or polymer solution requires high shear conditions.
[0005] It would be desirable to develop an improved method of sizing paper at the wet end that will use a simpler and less expensive, low shear equipment for the ASA emulsification.
SUMMARY
[0006] The invention relates to method for sizing a paper product that involves the steps of: (a) providing a paper stock system; (b) forming, in the absence of high shearing forces, an aqueous sizing emulsion comprising an alkenyl succinic anhydride component; (c) submitting the emulsion formed from step b to a post-dilution step in the presence of a cationic component under conditions, in the absence of high shearing forces, that produce a post-diluted emulsion having improved sizing efficacy; (d) adding the post-diluted emulsion to the paper stock; and (e) forming a paper web.
[0007] In one embodiment, the invention relates to a paper made by the above-mentioned process.
[0008] In one embodiment, the invention relates to a method for sizing a paper product comprising:
(a) providing a paper stock system; (b) forming, in the absence of high shearing forces, an aqueous sizing emulsion comprising an alkenylsuccinic anhydride component;
[0011] wherein the emulsion is made in the presence of a cationic component under conditions, in the absence of high shearing forces, that produce an emulsion having improved sizing efficacy;
(d) adding the emulsion to the paper stock; and (e) forming a paper web.
[0014] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims.
DESCRIPTION
[0015] Other than in operating examples or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, and the like, used in the specification and claims are to be understood as modified in all instances by the term “about.” Various numerical ranges are disclosed in this patent application. Because these ranges are continuous, they include every value between the minimum and maximum values. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations.
[0016] The emulsion prepared prior to the post-dilution step includes an alkenylsuccinic anhydride-containing emulsion, which when subjected to a post-dilution step, improves sizing efficacy as compared to an emulsion that is not subjected to a post-dilution step. The emulsion, for instance, can include an alkenylsuccinic anhydride component containing alkenylsuccinic anhydride particles suspended in a starch component containing emulsifying starch selected from the group consisting of non-ionic starches, anionic starches, cationic starches and mixtures thereof. Starches that are used for the emulsification can be based on corn, potato, wheat, tapioca, or sorghum, and they could be modified through the use of enzymes, high temperature or chemical/thermal converting techniques.
[0017] Alternatively, the emulsion can include an alkenylsuccinic anhydride component containing alkenylsuccinic anhydride particles suspended in an aqueous polymer solution selected from the group of cationic polymers, nonionic polymers, anionic polymers, vinyl addition polymers, condensation polymers, and mixtures thereof. In one version of the invention, the invention includes an alkenylsuccinic anhydride component containing (i) alkenylsuccinic anhydride particles and (ii) surfactant component; suspended in water.
[0018] The emulsion of step (b) can be made by any suitable method. Generally, the emulsion is made with an emulsifying agent, e.g., a surfactant. Cationic polymer or cationic starch may be present, but they are not required. The weight ratio of the alkenylsuccinic anhydride to polymer or starch solids generally ranges from 1 to 0.02 to 1:1, or from 1 to 0.05 to 1 to 0.5, or from 1 to 0.1 to 1 to 0.2. In one embodiment, for instance, the emulsion in step (b) can be made by emulsifying an alkenylsuccinic anhydride component containing (i) alkenylsuccinic anhydride and (ii) a surfactant component, with water; and thereby forming an emulsion having an alkenylsuccinic anhydride component containing (i) alkenylsuccinic anhydride particles and (ii) a surfactant component; suspended in water. Alternatively, the emulsion in step (b) can be made by emulsifying an alkenylsuccinic anhydride component, optionally containing a surfactant, with an aqueous polymer solution, and thereby forming the emulsion. The sizing emulsion can be formed with a polyoxyalkylene alkyl ether or one surfactant selected from the group consisting of sulfosuccinates, alkyl and aryl amides and primary, secondary and tertiary amines and their corresponding quaternary salts, fatty acids, ethoxylated fatty acids, fatty alcohols, ethoxylated fatty alcohols, fatty esters, ethoxylated fatty esters, ethoxylated triglycerides, certain ethoxylated lanolin, sulfonated amines, sulfonated amides, ethoxylated polymers, propoxylated polymers, ethoxylated/propoxylated copolymers, polyethylene glycols, phosphate esters, phosphonated fatty acid ethoxylates, phosphonated fatty alcohol ethoxylates, alkyl sulfonates, aryl sulfonates, alkyl sulfates, aryl sulfates, and combinations thereof.
[0019] The polymer used to emulsify the alkenylsuccinic anhydride can be any polymer, which when used in accordance with the invention, can produce an emulsion in accordance with the invention. Examples of suitable polymers used in the emulsion of this sizing composition include polymeric stabilizers that include vinyl addition and condensation polymers having anionic, cationic, non-ionic and amphoteric charge characteristics with a charge substitution range varying from 0 to about 90%, and more preferably from 0 to about 10%. Further, the molecular weight of aforementioned synthetic polymeric stabilizer generally falls within the value ranging from about 10,000 to about 10 million daltons, or from about 100,000 to about two million or from about 200,00 to about 1 million daltons. All molecular weights mentioned herein are weight average.
[0020] Generally, suitable water-soluble polymers of this instant invention are cationic vinyl addition polymers, anionic vinyl addition polymers, neutral polymers, ampholytic polymers and condensation polymers.
[0021] Examples of suitable polymers include, water-soluble polymers having molecular weights ranging from 10,000 daltons to 3,000,000 daltons. The substantially water-soluble polymers to be used in this invention are comprised of but not limited to homopolymers and copolymers, and combinations thereof leading to terpolymers, and tetrapolymers comprised of the following monomers: acrylamide, diallyldimethylammonium chloride, dimethylaminoethylacrylate, dimethylaminoethylacrylate quaternaries, diethylaminoethyl acrylate, diethylaminoethylacrylate quaternaries, dimethylaminoethylmethacrylate, dimethylaminoethylmethacrylate quaternaries, dimethylaminoethylmethacrylate and its quaternaries, methacrylamidopropyltrimethyl ammonium chloride, acrylic acid. Suitable polymers also include polymers and copolymers of acrylamide that have been subjected to the “Mannich” reaction. Also, in one embodiment, the corresponding Mannich quaternaries are possible water-soluble polymers. Examples of other water-soluble polymers include copolymers comprised of substantially water-soluble and water dispersible styrene-alkylacrylates, styrene alkylacrylics, styrene maleic acid, styrene-maleic acid amide, styrene maleic acid esters, styrene maleic acid amide ester, and their corresponding salts. In another embodiment, suitable polymers include aqueous dispersions containing combinations of the reaction products of the above monomers, polyurethane dispersions with polyvinyl alcohol, poly vinylalcohol-vinylamine), their corresponding acetates or formamates or partially hydrolyzed polymers, or polyvinylamine.
[0022] Examples include copolymers of N,N-dialkylamino-alkyl(meth) acrylates and/or amides and/or alkyl(meth)acrylates, styrene, isobutylene, diisobutylene, vinyl acetate and/or acrylonitrile. Examples include condensation polymers of trimethylene diamine and 1,2-dichloroethane or 1,3 dichloropropane; adipic acid with diethylenetriamine, tetraethylenepentamine or similar polyalkylene; polyamides; subsequent reaction products with epichlorohydrin; dimethylamine-epichlorohydrin; ethylenediamine polyacrylamide. Examples include polyvinyl pyridine, poly-N-methylpyridinium chloride; poly-p-chlorostyrene quaternized with trialkylamine. Examples of such suitable polymers are described in U.S. Pat. Nos. 4,657,946, 4,784,727, 3,445,330, 6,346,554, incorporated herein by reference in their entirety.
[0023] Natural polymers, gums, and their extracts included in the embodiments of the invention may be taken from the following list: guar, acacia, agar, algin, carrageenan, cellulose and its derivatives, chitin, chitosan, damar, dextran, dextrin, ethylcellulose, gelatin, gellan, jalap, karaya, kelp, locust bean, methylcellulose, olibanum, pectin, rhamsan, sandarac, tragacanth, welan, and xanthan. This includes the salts and derivatives of the natural polymers. The polymers may be in their natural state or derivatized thereafter to form salts or other derivatives (e.g. hydroxyethylated). The products may be anionic, cationic, amphoteric, or neutral.
[0024] The emulsion may be made in the absence of high shearing forces (low shear conditions), e.g., those shearing conditions are created by a device selected from the group of centrifugal pumps, static in-line mixers, peristaltic pumps, and combinations thereof.
[0025] The alkenylsuccinic anhydride component generally includes alkenylsuccinic anhydride compounds composed of mono unsaturated hydrocarbon chains containing pendant succinic anhydride groups. The alkenylsuccinic anhydride compounds are generally liquid and may be derived from maleic anhydride and suitable olefins. The alkenylsuccinic anhydride compounds may be solid.
[0026] Generally speaking, the alkenylsuccinic anhydride compounds may be made by reacting an isomerized C 14 -C 20 mono olefin, preferably an excess of an internal olefin, with maleic anhydride, at a temperature and for a time sufficient to form the alkenylsuccinic anhydride compound.
[0027] If the olefin to be employed in the preparation of the alkenylsuccinic anhydride compounds is not an internal olefin as is the case for example, with α-olefins, it may be preferable to first isomerize the olefins to provide internal olefins. The olefins that may be used in the preparation of the alkenylsuccinic anhydride compounds may be linear or branched. Preferably, the olefins may contain at least about 14 carbon atoms. Typical structures of alkenylsuccinic anhydride compounds are disclosed, for example, in U.S. Pat. No. 4,040,900, incorporated herein by reference in its entirety. Alkenylsuccinic anhydride compounds and methods for their preparation are described, for example, in C. E. Farley and R. B. Wasser, “The Sizing of Paper, Second Edition,” edited by W. F. Reynolds, TAPPI Press, 1989, pages 51-62, the disclosures of which are hereby incorporated herein by reference in its entirety.
[0028] The alkenylsuccinic anhydride component may contain some hydrolyzed alkenylsuccinic anhydride. The amount of hydrolyzed alkenylsuccinic anhydride may range from about 1 to about 30 wt. %, based on the total weight of the alkenylsuccinic anhydride component.
[0029] The alkenylsuccinic anhydride component can include:
[0030] a. from 80 to 97 parts of substituted cyclic dicarboxylic acid anhydride corresponding to the formula
[0000]
[0031] wherein R represents a dimethylene or trimethylene radical and wherein R′ is a hydrophobic group containing more than 5 carbon atoms which may be selected from the class consisting of alkyl, alkenyl, aralkyl, or aralkenyl groups;
[0000]
[0032] wherein R x is an alkyl radical containing at least 5 carbon atoms and R y is an alkyl radical containing at least 5 carbon atoms, and R x and R y are interchangeable;
[0000]
[0000] wherein R x is an alkyl radical containing at least 5 carbon atoms and R y is an alkyl radical containing at least 5 carbon atoms and R x and R y are interchangeable; and
[0033] b. from 3 to 20 parts of a polyoxyalkylene alkyl or polyoxyalkylene alkyl-aryl ether or the corresponding mono- or diester selected from the group consisting of:
[0000]
[0034] wherein x and n are integers in the range of 8 to 20; R is an aryl radical; m is an integer in the range of 5 to 20; and i is 0, 1, or 2.
[0035] The alkenylsuccinic anhydride component is generally present in the emulsion in an amount that is at least about 0.01 wt. %, or from about 0.1 to about 20 wt. %, or from about 0.3 wt. % to about 15 wt. %, based on the total weight of the emulsion. The emulsion generally contains alkenylsuccinic anhydride particles ranging from 0.5 microns to less than 3 microns.
[0036] When a surfactant is used to make the emulsion, the surfactant component includes surfactants, which when used to make an emulsion in accordance with the invention, produces an emulsion that minimizes coalescing and imparts useful sizing properties to a fibrous substrate after the emulsion contacts the fibrous substrate. The surfactant component functions as an emulsifying agent when the emulsion is made. The surfactant component facilitates the emulsification of the alkenylsuccinic anhydride with the water component when the emulsion is made. Generally, the surfactants are anionic or nonionic or can be cationic and can have a wide range of HLB values.
[0037] Examples of suitable surfactants include but are not limited to alkyl and aryl primary, secondary and tertiary amines and their corresponding quaternary salts, sulfosuccinates, fatty acids, ethoxylated fatty acids, fatty alcohols, ethoxylated fatty alcohols, fatty esters, ethoxylated fatty esters, ethoxylated triglycerides, sulfonated amides, sulfonated amines, ethoxylated polymers, propoxylated polymers or ethoxylated/propoxylated copolymers, polyethylene glycols, phosphate esters, phosphonated fatty acid ethoxylates, phosphonated fatty alcohol ethoxylates, and alkyl and aryl sulfonates and sulfates. Examples of preferred suitable surfactants include but are not limited to amides; ethoxylated polymers, propoxylated polymers or ethoxylated/propoxylated copolymers; fatty alcohols, ethoxylated fatty alcohols, fatty esters, carboxylated alcohol or alkylphenol ethoxylates; carboxylic acids; fatty acids; diphenyl sulfonate derivatives; ethoxylated alcohols; ethoxylated fatty alcohols; ethoxylated alkylphenols; ethoxylated amines; ethoxylated amides; ethoxylated aryl phenols; ethoxylated fatty acids; ethoxylated triglycerides; ethoxylated fatty esters; ethoxylated glycol esters; polyethylene glycols; fatty acid esters; glycerol esters; glycol esters; certain lanolin-based derivatives; monoglycerides, diglycerides and derivatives; olefin sulfonates; phosphate esters; phosphorus organic derivatives; phosphonated fatty acid ethoxylates, phosphonated fatty alcohol ethoxylates; polyethylene glycols; polymeric polysaccharides; propoxylated and ethoxylated fatty acids; alkyl and aryl sulfates and sulfonates; ethoxylated alkylphenols; sulfosuccinamates; sulfosuccinates.
[0038] In one embodiment, the surfactant component includes an amine selected from the group consisting of trialkyl amine of the formula (I):
[0000]
[0000] dimethyl sulfate quaternary salt of trialkyl amine of the formula (I), benzyl chloride quaternary salt of trialkyl amine of the formula (I), and diethyl sulfate quaternary salt of trialkyl amine of the formula (I), in which R 1 is methyl or ethyl, R 2 is methyl or ethyl, and R 3 is alkyl having 14 to 24 carbon atoms. In another embodiment, the surfactant excludes this amine.
[0039] The surfactant levels can range from about 0.1 weight % up to about 20 weight % based on the alkenylsuccinic anhydride component.
[0040] It has been discovered that the following examples do not provide suitable results (produce paper products with useless sizing properties) under certain conditions: sorbitan monolaurate (Arlacel 20), ethoxylated sorbitan trioleate (Tween 85), propoxylated lanolin (Solulan PB-5), ethoxylated lanolin (Laneto 100), sorbitan trioleate (Span 85), isostearic alkanolamide (Monamid 150-IS), hydroxylated milk glycerides (Cremophor HMG), bis(tridecyl) ester of sodium sulfosuccinic acid (AEROSOL® TR-70).
[0041] The post-dilution step generally involves mixing the emulsion with a cationic component at autogenous conditions. The cationic component can be selected from the group consisting of cationic starches, cationic polymers, cationic starch-grafted polymers, and mixtures thereof. Also, the cationic component can be selected from the group consisting of cationic vinyl addition polymers, cationic condensation polymers, and combinations thereof. Starches that are used for the post-dilutation step can be based on corn, potato, wheat, tapioca, or sorghum, and they could be modified through the use of enzymes, high temperature or chemical/thermal converting techniques. The starches that are used for the post-dilution have to be cationic.
[0042] The ratio of the cationic component solids to the alkenylsuccinic anhydride in the post-dilution step should range from 0.1:1 to 4:1, but in some cases could be as high as 50:1. This ratio will depend on the requirements for a specific paper production application.
[0043] The temperature at which the process of the invention can be carried out is generally less than 50° C. The pH at which the process of the invention is practiced varies, depending on the application. The pH, for instance, can range from 4 to 8 or from 6 to 8. The post-dilution step is generally carried out under low shear conditions e.g., those shearing conditions are created by a device such as selected from the group of centrifugal pumps static in-line mixers, peristatic pumps, magnetic stirring bar in a beaker, overhead stirrer, and combinations thereof. Although the post dilution step is typically carried out, in one embodiment, if alkenyl succinic anhydride is emulsified in a cationic component than the post-dilution with a second cationic component is optional.
[0044] The duration of the mixing in step(c) generally occurs less than one minute. For instance, the mixing in step(c) can occur from 1 to 20 seconds.
[0045] The stability of the post-diluted composition varies. For instance, the stability of the post-diluted composition can be stable from 1 to 6 hours.
[0046] The method of the invention provides valuable advantages. For instance, the paper sized in accordance with the invention generally exhibits a sizing efficiency that is more than 20% higher, as compared to paper made with a composition that is not subjected to a post-dilution step. The paper that can be sized with the method of the invention can be selected from the group consisting of paperboard papers, fine papers, newsprint papers, and combinations thereof.
[0000] As such, the invention can also be directed to the papers treated with Applicants' invention.
[0047] The invention is further described in the following illustrative examples in which all parts and percentages are by weight unless otherwise indicated.
EXAMPLES
Handsheets Studies
Examples 1-12
[0048] Evaluation of a low shear alkenylsuccinic anhydride (ASA) performance was done by preparation of ASA emulsions with water, polymers or starch, characterization of the emulsion particle size distribution, addition of these emulsions to the paper furnish, forming paper handsheets and measuring the sizing of paper handsheets. The performance of the low shear emulsion was compared to a conventional, high shear ASA emulsion.
[0049] Emulsification of Low Shear ASA in Water Using a Centrifugal Pump—Method 1
[0050] Alkenylsuccinic anhydride (ASA) containing 5% Brij® 98 surfactant was emulsified in water with a single impeller, open-feed, 1-horsepower centrifugal pump at a speed of 1700 rpm. The low shear centrifugal pump was connected to a tap water supply and the pump was operated using the pressure from the tap water supply. No pH or temperature adjustment was made to the tap water prior to emulsification. ASA was supplied to the centrifugal pump from a calibration column via a gear pump. ASA entered the water inlet just before the centrifugal pump. The water flow rate was approximately 1 L/min and ASA flow rate was approximately 240 mL/min. The centrifugal pump was a single-pass emulsification process with no recirculation. The resulting ASA emulsion contained 19 weight percent ASA.
[0051] Emulsification of Low Shear ASA in Polymer or Starch Solution Using a Centrifugal Pump—Method 2
[0052] The emulsification of ASA containing 5% Brij 98 surfactant in polymer or starch solution was done as the emulsification in water, except that polymer or starch were added to a water line using a variable speed gear pump, and it was mixed using an in-line static mixer before it was combined with ASA flow. The centrifugal pump was run at a speed between 1700 and 3600 rpm. The concentration of ASA in the emulsion varied from about 3 to about 10 wt %, depending on particular study. The total flow rate of water, ASA and polymer or starch was about 1 L/min.
[0053] Emulsification of ASA with High Shear
[0054] A high shear ASA, BAYSIZE® I 18 size (LANXESS Corporation) emulsion were prepared with a polymer or starch solution using a household blender on high speed for 90-180 sec. See details in examples.
[0055] Emulsion Particle Size Analysis
[0056] A commercially available, light scattering, particle analyzer, Horiba LA-300 was used to determine the particle size of the emulsions. Results are reported as the median particle size in microns.
[0057] Handsheet Preparation Process Used in Examples 1-10
[0058] Handsheets were prepared using a furnish of a 50/50 mixture of bleached hardwood and softwood kraft pulp refined to a Canadian Standard Freeness (CSF) of 500 mL to which 10% by weight of precipitated calcium carbonate was added, and pH was adjusted to 7.8.
[0059] Deionized water was used for furnish preparation and additional 80 ppm of sodium sulfate and 50 ppm of calcium chloride were added.
[0060] While mixing, a batch of pulp at 0.71% solids containing 17 g of cellulose fibers and calcium carbonate was treated with an ASA emulsion that was diluted to 0.25 wt. % with tap water. Alum was also added to the batch and applied at a dose of 5 lb per ton of dry fiber. Alum was applied 30 sec prior to ASA emulsion addition. After a 60-sec contact time, 1 lb per ton on dry fiber of an anionic retention aid was added, and mixing continued for 15 sec.
[0061] Three 5.0 g sheets of paper were formed using a standard (8″×8″) Nobel & Woods handsheet mold, to target a basis weight of 121 g/m 2 . Each sheet was pressed between felts in the nip of a pneumatic roll press at about 15 psig and dried on a rotary dryer at 240° F.
[0062] Paper Sizing Evaluation Procedures
[0063] A 2-min Cobb test or Ink Penetration Holdout test was used to evaluate the sizing paper.
[0064] 2-Min Cobb Test
[0065] The sizing of handsheets was tested using a 2-min Cobb test. The test was performed according to TAPPI Test Method T441 om-90. A 100-cm 2 ring was utilized in this test.
[0066] Ink Penetration Holdout
[0067] Ink Penetration Holdout was measured using a method similar to that described in TAPPI Method T 530 pm-89 except that an instrument was used as described in U.S. Pat. No. 5,483,078. The test measures the time (in seconds) for the reflectance of the paper on the side opposite that contacting the ink to decreases to 80% of the initial value. The ink consists of 1.25% Naphthol Green B dye buffered to pH 7. The test values were normalized for basis weight of the paper assuming that the values vary as the cube of the basis weight. Results were expressed in units of seconds.
Example 1
[0068] ASA containing 5 wt % of Brij 98 surfactant was emulsified in an aqueous solution of the high molecular weight cationic acrylamide polymer, BAYSIZE® E LS polymer (LANXESS Corporation) at a sizing agent to polymer solids ratio of 1/0.1.
[0069] The emulsification was done according to Method 2, using a centrifugal pump at a speed of 3000 rpm. During the emulsification process, the ASA flow was 53 mL/min, the 10.8% (w/w) polymer solution flow was 47 mL/min, and water flow was 1030 mL/min. The sizing agent concentration in the emulsion was 4.88% (w/w). The emulsion particle size was 1.18 microns. The handsheets were prepared with this emulsion and the sizing of these handsheets was measured using a 2-min Cobb test.
Example 2 (Comparative)
[0070] BAYSIZE I 18 size (LANXESS Corporation) was emulsified in the aqueous solution of the high molecular weight cationic acrylamide polymer BAYSIZE E LS polymer (LANXESS Corporation) at a sizing agent to polymer solids ratio of 1/0.1. During the emulsification process, 20.2 g of BAYSIZE I 18 size (LANXESS Corporation) was added to 100 g of 2.02 (w/w) polymer solution and mixed in a household blender on high speed for 3 min. The emulsion particle size was 0.72 microns. The handsheets were prepared with this emulsion and the sizing of these handsheets was measured using a 2-min Cobb test.
[0000]
TABLE 1
Performance of Sizing Agents Emulsified with
a High Molecular Weight Cationic Polymer.
2-min Cobb Sizing (g/m 2 )
4.25 lb/t of
4.25 lb/t of
5.25 lb/t of
6.25 lb/t of
sizing agent;
Example
sizing agent
sizing agent
sizing agent
5 lb/t of alum
Example 1
54.5
35
30.5
26.5
Example 2
38.0
28.5
30.0
25.5
(compara-
tive)
[0071] The emulsion of a low shear ASA (Example 1) provided worse paper sizing than the high shear ASA emulsion (Example 2) at a low sizing agent dose, but as the dose was increased or as 5 lb/t of alum was applied, the sizing performance of both sizing agents was equivalent.
Example 3
[0072] ASA containing 5% (w/w) of Brij 98 surfactant was emulsified in the aqueous solution of the low molecular weight cationic acrylamide polymer BAYSIZE® E HE polymer (LANXESS Corporation) at a sizing agent to polymer solids ratio of 1/0.15.
[0073] The emulsification was done according to Method 2, using a centrifugal pump at a speed of 1700 rpm. During the emulsification process, the ASA flow was 50 mL/min, the 26-wt. % polymer solution flow was 26 mL/min, and water flow was 1909 mL/min. The sizing agent concentration in the emulsion was 4.8 wt. %. The emulsion particle size was 2.3 microns. The handsheets were prepared with this emulsion, and the sizing of these handsheets was measured using a 2-min Cobb test.
Example 4 (Comparative)
[0074] BAYSIZE I 18 size (LANXESS Corporation) was emulsified in the aqueous solution of the low molecular weight cationic acrylamide polymer BAYSIZE E HE polymer (LANXESS Corporation) at a sizing agent to polymer solids ratio of 1/0.15. During the emulsification process, 20.2 g of BAYSIZE I 18 size (LANXESS Corporation) was added to 101 g of 3% (w/w) polymer solution and mixed in a household blender on high speed for 3 min. The emulsion particle size was 1.1 microns. The handsheets were prepared with this emulsion, and the sizing of these handsheets was measured using a 2-min Cobb test.
[0000]
TABLE 2
Performance of Sizing Agents Emulsified with
a Low Molecular Weight Cationic Polymer.
2-min Cobb Sizing (g/m 2 )
4.5 lb/t of
4.5 lb/t of
5.5 lb/t of
6.5 lb/t of
sizing agent,
Example
sizing agent
sizing agent
sizing agent
5 lb/t of alum
Example 3
104.5
73.0
28.0
25.5
Example 4
66
36.5
29.5
26.5
(compara-
tive)
[0075] The sizing performance of the low shear ASA emulsified with the low molecular weight cationic polymer (Example 3) matched the performance of the high shear ASA emulsified with the same low molecular cationic polymer (Example 4) when a higher dose of sizing agent was used. The sizing performance was also matched when a lower dose of sizing agent was used in conjunction with alum.
Example 5
[0076] ASA containing 5% (w/w) of Brij 98 surfactant was emulsified in a solution of Hi-Cat CWS pregelatinized starch (Roquette) at a sizing agent to starch solids ratio of 1/1. The emulsification was done according to Method 2, using a centrifugal pump at a speed of 2400 rpm. During the emulsification process, the ASA flow was 44.5 mL/min, the 4.19% (w/w) starch solution flow was 955.5 mL/min, and there was no water flow. The sizing agent concentration in the emulsion was 4.21% (w/w). The emulsion particle size was 3.6 microns. The handsheets were prepared with this emulsion, and the sizing of these handsheets was measured using a 2-min Cobb test.
Example 6
[0077] ASA containing 5% (w/w) of Brij 98 surfactant was emulsified in tap water.
[0078] The emulsification was done according to Method 1, using a centrifugal pump at a speed of 1700 rpm. During the emulsification process, the ASA flow was 44.5 mL/min, the water flow was 955.5 mL/min. The sizing agent concentration in the emulsion was 4.2% (w/w). The emulsion particle size was 1.5 microns. The emulsion was post-diluted with the 4.19% (w/w) solution of Hi-Cat CWS pregelatinized starch (Roquette). The sizing agent to starch solids ratio in the post-diluted emulsion was 1/1. The handsheets were prepared with this emulsion, and the sizing of these handsheets was measured using a 2-min Cobb test.
Example 7 (Comparative)
[0079] BAYSIZE I 18 size (LANXESS Corporation) was emulsified in an aqueous solution of Hi-Cat CWS pregelatinized starch (Roquette) at a sizing agent to starch solids ratio of 1/1.
[0080] During the emulsification process, 8.08 g of BAYSIZE I 18 size (LANXESS Corporation) was added to 191.92 g of the 4.19% (w/w) starch solution and mixed in a household blender on high speed for 90 seconds. The emulsion particle size was 0.62 microns.
[0000] The handsheets were prepared with this emulsion, and the sizing of these handsheets was measured using a 2-min Cobb test.
[0000]
TABLE 3
Performance of Sizing Agents Emulsified
in Starch or Post-diluted with Starch.
2-min Cobb Sizing (g/m 2 )
4.25 lb/t of
5.25 lb/t of
6.25 lb/t of
Example
sizing agent
sizing agent
sizing agent
Example 5
44.0
26.5
27.0
Example 6
137.5
72.5
33.5
Example 7
34.0
27.0
25.5
(comparative)
[0081] The low shear ASA emulsified in a cationic starch solution (Example 5) provided similar performance to the high shear ASA emulsified in the same starch solution (Example 7). Worse performance was achieved when the low shear ASA was emulsified in water and post-diluted with starch solution to provide the sizing agent to starch solids ratio of 1/1.
Example 8
[0082] The amount of 6.0 g of ASA containing 5 wt % of Brij 98 surfactant was emulsified with 114 g of 0.53% (w/w) aqueous solution BAYSIZE® E HE polymer (LANXESS Corporation), using a household blender on low speed for 30 second. The emulsion particle size was 1.3 microns. The handsheets were prepared with this emulsion. During the handsheets making process, each set was treated with 5 lb/t of alum. The sizing of these handsheets was measured using a 2-min Cobb test.
Example 9
[0083] ASA, 6.0 g, containing 5% (w/w) of Brij 98 surfactant was emulsified in 114.0 g of tap water, using a household blender on low speed for 30 second. The emulsion particle size was 0.95 microns. Ten grams of the emulsion was post-diluted with 190 g of 0.026-wt. % aqueous solution of the low molecular weight cationic acrylamide polymer BAYSIZE E HE polymer (LANXESS Corporation). The handsheets were prepared with this emulsion. During the handsheets making process, each set was treated with 5 lb/t of alum. The sizing of these handsheets was measured using a 2-min Cobb test.
Example 10 (Comparative)
[0084] BAYSIZE I 18 size (LANXESS Corporation) was emulsified in the aqueous solution of the low molecular weight cationic acrylamide polymer BAYSIZE E HE polymer (LANXESS Corporation) at a sizing agent to polymer solids ratio of 1/0.1. During the emulsification process, 20 g of BAYSIZE I 18 size (LANXESS Corporation) was added to 100 g of 2% (w/w) polymer solution and mixed in a household blender on high speed for 3 min. The emulsion particle size was 1.0 micron. The handsheets were prepared with this emulsion. During the handsheets making process, each set was treated with 5 lb/t of alum. The sizing of these handsheets was measured using a 2-min Cobb test.
[0000]
TABLE 4
Performance of Sizing Agents Emulsified or Post-diluted
with a Low Molecular Weight Cationic Polymer.
2-min Cobb Sizing (g/m 2 )
4.0 lb/t of
5.0 lb/t of
6.0 lb/t of
sizing agent;
sizing agent;
sizing agent;
Example
5 lb/t of alum
5 lb/t of alum
5 lb/t of alum
Example 8
24.6
18.8
26.9
Example 9
35.0
27.4
15.3
Example 10
25.7
24.4
24.1
(comparative)
[0085] As this is shown in Table 4, the application of alum in the handsheets making process improved the performance of a low shear ASA. The performance of the low shear ASA emulsified in the low molecular weight cationic polymer (Example 8) provided comparable performance to the high shear ASA (Example 10) over the broad dose range. The low shear ASA that was emulsified in water and post-diluted with the polymer solution (Example 9) provided worse sizing than ASA emulsified with the polymer, but the difference in the performance was rather small.
Example 11
[0086] ASA, 6.0 g, containing 5% (w/w) of Brij 98 surfactant was emulsified in 114.0 g of tap water, using a household blender on low speed for 30 second. The emulsion particle size was 1.03 microns. The emulsion was post-diluted to 0.25% (w/w) with tap water, and than mixed with a 1% (w/w) cationic starch solution. The 82 g/m 2 basis weight handsheets were prepared with this emulsion. Handsheets were made with the recycled furnish obtained from a board mill. During the handsheet-making process, each set was first treated with polyaluminum chloride at a dose of 12 lb/t of dry fiber. After 30 sec, the mixture of ASA emulsion and starch was added to the furnish. The mixture of ASA emulsion provided 20 lb of dry starch per ton of dry fiber. After a 60-sec contact time, an anionic retention aid was added at a dose of 1 lb/t of dry fiber, and mixing continued for 15 sec. Ink Penetration Holdout was used to evaluate the paper sizing.
Example 12 (Comparative)
[0087] This example was like Example 11, except that the ASA emulsion and the starch solution was added separately to the furnish. ASA, 6.0 g, containing 5% (w/w) of Brij 98 surfactant was emulsified in 114.0 g of tap water, using a household blender on low speed for 30 sec. The emulsion particle size was 1.03 microns. The handsheets were prepared with this emulsion. Handsheets were made with recycled furnish. During the handsheet-making process, each set was first treated with polyaluminium chloride at a dose of 12 lb per ton of dry fiber. After 30 sec, the ASA emulsion was added and mixed with furnish for 5 sec before 20 lb of cationic starch per ton of dry fiber was added. After 55 sec, 1 lb of an anionic retention aid per ton of dry fiber was added, and mixing continued for 15 sec. Ink Penetration Holdout was used to evaluate paper sizing.
[0000]
TABLE 5
Post-dilution of Low Shear ASA Emulsion with Starch vs. Separate
Addition of ASA Emulsion and Starch to the Furnish.
Neutral Ink Holdout (sec)
0.12 lb/t of
0.25 lb/t of
0.5 lb/t of
Example
sizing agent
sizing agent
sizing agent
Example 11
308
740
2197
Example 12
240
259
354
(comparative)
[0088] The post-dilution of the low shear ASA emulsion with cationic starch solution prior to the addition of ASA emulsion to the furnish (Example 11) provided significantly higher paper sizing than the separate addition of ASA emulsion and starch to the furnish (Example 12).
Example 13-17
[0089] Evaluation of low shear alkenylsuccinic anhydride (ASA) performance was done by preparation of ASA emulsions in water or in a polymer solution, or post-dilution of ASA emulsified in water with starch or polymer solution, and addition of these emulsions to the paper furnish during a pilot machine paper making process. The sizing performance of the low shear emulsion was compared to a conventional, high shear ASA emulsion, using a 2-min Cobb test.
Paper Furnish
[0090] A 30/70 blend of bleached northern softwood Kraft refined to 420 mL CSF and bleached northern hardwood Kraft refined to 350 mL CSF was applied in the pilot machine papermaking process. Precipitated calcium carbonate was added to the machine chest in the amount of 10 wt. % on dry fiber. The basis weight of the paper produced on the pilot machine was 120 gm 2 .
Pilot Paper Machine Operating Conditions
[0091] The pilot machine speed is 85 feet per minute, giving a production rate of about 1.16 lb/min. The pH of the paper furnish was maintained between 7.9 and 8.4. The ASA emulsions were diluted with tap water to 0.5% (w/w) concentration before the addition to the paper furnish. An anionic retention aid in the amount of 0.5 lb per ton of dry paper was applied. The paper moisture content was 4% (w/w) at the reel.
Example 13
[0092] ASA containing 5% (w/w) of Brij 98 surfactant was emulsified in an aqueous solution of the low molecular weight cationic acrylamide polymer BAYSIZE E HE polymer (LANXESS Corporation) at a sizing agent to polymer solids ratio of 1/0.12.
[0093] The emulsification was done according to Method 2, using a centrifugal pump at a speed of 3300 rpm. During the emulsification process, the ASA flow was 50 mL/min, the 13.27% (w/w) polymer solution flow was 40 mL/min, and water flow was 810 mL/min. The sizing agent concentration in the emulsion was 5.26% (w/w). The emulsion particle size was 1.17 microns. This emulsion was applied as an internal sizing agent to produce paper on the pilot paper machine. The sizing of the felt and wire side of this paper was measured using a 2-min Cobb test.
Example 14
[0094] ASA containing 5% (w/w) of Brij 98 surfactant was emulsified in tap water.
[0095] The emulsification was done according to Method 1, using a centrifugal pump at a speed of 1700 rpm. During the emulsification process, the ASA flow was 50.0 mL/min, the water flow was 850 mL/min. The sizing agent concentration in the emulsion was 5.26% (w/w). The emulsion particle size was 1.44 microns. The emulsion was post-diluted with the 0.05% (w/w) of BAYSIZE E HE polymer (LANXESS Corporation). The sizing agent to polymer solids ratio in the post-diluted emulsion was 1/0.1, and the ASA concentration was 0.5 wt. %. This emulsion was applied as an internal sizing agent to produce paper on the pilot paper machine. The sizing of the felt and wire side of this paper was measured using a 2-min Cobb test.
Example 15 (Comparative)
[0096] BAYSIZE I 18 size (LANXESS Corporation) was emulsified in the aqueous solution of the low molecular weight cationic acrylamide polymer BAYSIZE E HE polymer (LANXESS Corporation) at a sizing agent to polymer solids ratio of 1/0.1. During the emulsification process, 240 g of BAYSIZE I 18 size (LANXESS Corporation) was added to 180.86 g of a 13.25% (w/w) polymer solution and 1019.71 g of tap water, and the mixture stirred in an industrial blender on low speed for 1.5 min. The emulsion particle size was 1.15 microns. Handsheets were prepared with this emulsion. This emulsion was applied as an internal sizing agent to produce paper on the pilot paper machine. The sizing of the felt and wire side of this paper was measured using a 2-min Cobb test.
[0000]
TABLE 5
Performance of Sizing Agents Emulsified with a Low Molecular
Weight Cationic Polymer. Data from the Pilot Machine Trial.
2-min Cobb Sizing (g/m 2 )
4.0 lb/t of
5.0 lb/t of
4.0 lb/t of
5.0 lb/t of
6.0 lb/t of
sizing agent;
sizing agent,
Example
sizing agent
sizing agent
sizing agent
5 lb/t of alum
5 lb/t of alum
Example 13
119.8
77.5
39.6
31.5
32
Example 14
49.5
Example 15
124.8
87.5
43.8
39.5
34.5
(comparative)
[0097] The low shear ASA (Example 13) provided slightly better sizing than the high shear ASA (Example 15) over a broad dose range when both sizing agents were applied at the wet-end of paper making process on the pilot machine. The low shear ASA emulsified in water and post-diluted with a cationic polymer solution (Example 14) provided a good sizing response, however the sizing was lower than the sizing obtained with the low shear ASA emulsified in the polymer solution (Example 13).
Example 16
[0098] ASA containing 5% (w/w) of Brij 98 surfactant was emulsified in tap water, as it was described in Example 14. The emulsion was post-diluted with a 2.2. % (w/w) solution of the Hi-Cat CWS pregelatinized starch (Roquette). The sizing agent to starch solids ratio in the post-diluted emulsion was 1/4, and the ASA concentration was 0.5% (w/w). This emulsion was applied as an internal sizing agent to produce paper on the pilot paper machine. The sizing of the felt and wire side of this paper was measured using a 2-min Cobb test.
Example 17 (Comparative)
[0099] BAYSIZE I 18 size (LANXESS Corporation) was emulsified in an aqueous solution of the Hi-Cat CWS pregelatinized starch (Roquette) at a sizing agent to starch solids ratio of 1/1. During the emulsification process, 80 g of BAYSIZE I 18 size (LANXESS Corporation) was added to 1920 g of 4.17% (w/w) starch solution and mixed in an industrial blender on low speed for 30 sec. The emulsion particle size was 1.37 microns. The emulsion was post-diluted with a 1.7% (w/w) solution of the Hi-Cat CWS pregelatinized starch (Roquette). The sizing agent to starch solids ratio in the post-diluted emulsion was 1/4, and the ASA concentration was 0.5% (w/w). The handsheets were prepared with this emulsion. This emulsion was applied as an internal sizing agent to produce paper on the pilot paper machine. The sizing of the felt and wire side of this paper was measured using a 2-min Cobb test.
[0000]
TABLE 6
Performance of Sizing Agents Emulsified
in Starch or Post-diluted with Starch.
2-min Cobb Sizing (g/m 2 )
4.0 lb/t of
7.0 lb/t of
8.0 lb/t of
Example
sizing agent
sizing agent
sizing agent
Example 16
41.3
36.5
32.3
Example 17
29.8
(comparative)
[0100] The results in Table 6 indicate that the low shear ASA post-diluted with the cationic starch is less effective in terms paper sizing as the high shear ASA emulsified in the cationic starch. However, the simplicity of the emulsification process of the low shear ASA and acceptable sizing response gives the paper maker operational and cost benefits in using this system.
[0101] Although the present invention has been described in detail with reference to certain preferred versions thereof, other variations are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the versions contained therein.
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The invention relates to a method for sizing a paper product that involves the steps of (a) providing a paper stock system; (b) forming, in the absence of high shearing forces, an aqueous sizing emulsion comprising an alkenylsuccinic anhydride component; (c) submitting the emulsion formed from step b to a post-dilution step in the presence of a cationic component under conditions, in the absence of high shearing forces, that produce a post-diluted emulsion having improved sizing efficacy; (d) adding the post-diluted emulsion to the paper stock; and (e) forming a paper web.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is the U.S. national phase application based on PCT Application No. PCT/EP2011/062239 filed Jul. 18, 2011, which is based on European Application No. 10172261.9 filed Aug. 9, 2010 and U.S. Provisional Application No. 61/371,830 filed Aug. 9, 2010, the entire contents of all of which are hereby incorporated by reference.
BACKGROUND
1. Field
The present invention relates to a compact, reliable and low-cost vector velocimeter for example for determining velocities of particles suspended in a gas or fluid flow, or for determining velocity, displacement, rotation, or vibration of a solid surface.
2. Description of the Related Art
LIDAR (Light Detection And Ranging) systems are well-known in the art. LIDAR determines velocity in the direction of line-of-sight based on detection of backscattered coherent light from airborne aerosols or particles in a measurement volume formed by a laser beam emitted by the LIDAR.
WO 2009/046717, which is hereby incorporated in its entirety by reference, discloses a LIDAR system with an all-semiconductor light source for emission of a laser beam for illumination of aerosols or particles in the measurement volume. The disclosed LIDAR system determines velocity magnitudes along the direction of propagation of the emitted laser beam. Possible velocity components in directions perpendicular to the direction of propagation of the emitted laser beam are not determined.
SUMMARY
Embodiments provide a vector velocimeter that is capable of determining a velocity vector, i.e. the magnitude of the velocity and the direction in one, two, or three dimensions, and which is compact, reliable and can be manufactured at low cost.
According to embodiments the above-mentioned and other features are obtained by provision of a vector velocimeter comprising a source of electromagnetic radiation that is arranged for emission of a measurement beam of electromagnetic radiation, e.g. spatially coherent light, directed towards a measurement volume for illumination of an object in the measurement volume.
According to embodiments a vector velocimeter is provided, wherein the vector velocimeter comprises a laser assembly for emission of a measurement beam for illumination of an object in a measurement volume with coherent light whereby a signal beam emanating from the object in the measurement volume is formed in response to illumination of the object by the measurement beam.
The vector velocimeter may further comprise a reference beam generator for generation of a reference beam. The vector velocimeter may be configured such that the reference beam and the measurement beam are emitted from the same laser source. The reference beam and the measurement beam may thereby be mutually coherent.
The vector velocimeter may further comprise a detector system comprising a first detector arrangement arranged in such a way that the signal beam and the reference beam are incident upon the first detector arrangement with the reference beam propagating at a first angle relative to a signal beam.
The first detector arrangement may comprise a first detector array of first detector elements, each of the first detector elements converting the intensity of the interfering signal beam and reference beam incident thereupon into a corresponding electronic detector element signal thereby generating an oscillating electronic detector element signal when the fringe pattern formed by the interfering signal beam and reference beam moves across the first detector array.
The vector velocimeter may further comprise a signal processor that is adapted for generation of a velocity signal corresponding to a first velocity component of movement of the object in the measurement volume in the longitudinal direction of the measurement volume based on the electronic detector element signals from each of the first detector elements.
The source of electromagnetic radiation may be a laser, such as a He—Ne laser or a semiconductor laser, e.g. included in a laser assembly, arranged for emission of the measurement beam.
The semiconductor laser may be a vertical external cavity surface-emitting laser (VECSEL) for emission of a high power beam. In a VECSEL, electromagnetic radiation is emitted perpendicular to the junction and the surface of the diode chip. The semiconductor chip or device, also denoted the gain chip, may contain a single semiconductor Bragg mirror and the active region (gain region) with typically several quantum wells (QWs). The device may have a total thickness of only a few micrometers. The laser resonator is completed with an external mirror.
The large transverse area of a VECSEL facilitates fundamental mode operation and leads to a high beam quality. Furthermore, the output beam of the VECSEL may be circular symmetrical with an insignificant amount of astigmatism leading to simple imaging properties.
The laser material in the electromagnetic cavity may be pumped optically. Optical pumping facilitates uniform pumping of large active areas. The optical pump source may for example be a high-brightness edge emitting broad-area diode or a diode laser bar. It is possible to achieve tens of watts of output power when pumping with a diode bar. Utilisation of an external resonator may facilitate provision of a diffraction-limited output.
The semiconductor laser may be a tapered semiconductor laser. Due to its tapered structure, the tapered semiconductor laser provides a high output power at its large area output facet, e.g. having a width of app. 250 μm, with a high beam quality since the ridge-waveguide at the narrow end, e.g. having a width of app. 3 μm, of the tapered laser forms a single mode spatial filter.
The vector velocimeter may furthermore comprise a semiconductor tapered power amplifier for amplification of the beam emitted by the semiconductor laser, for example the semiconductor laser and amplifier are of the semiconductor master-oscillator-power-amplifier (MOPA) type.
For example, a MOPA assembly may have a semiconductor master oscillator followed by a semiconductor tapered power amplifier; both realized on the same substrate constituting a cheap, rugged solution, ideal for industrial applications.
For example, an output power of approximately 1 Watt has been provided by a semiconductor MOPA assembly, even at a wavelength of 1.5 μm where the electron to photon conversion is less efficient as compared to the case for the 800 nm range. A wavelength of 1.5 μm or more is important for practical vector velocimeter use, since 1.5 μm is within the eye-safe region of the optical spectrum. The laser safety requirements during operation are more easily met when operated at eye-safe wavelengths.
Furthermore, the temporal coherency of tapered semiconductor laser assemblies, i.e. the coherence length, is sufficient for coherent vector velocimeter applications.
Still further, even though the spatial coherence of the output beam of a tapered semiconductor device is not perfect when compared to that of a diffraction-limited Gaussian beam, the laser assembly output beam is of sufficient quality to be used in a vector velocimeter. Spatial low-pass filtering of the output beam can remove or reduce the non-Gaussian spatial components that otherwise may lead to a reduced signal-to-noise ratio of the detector signal.
A vector velocimeter with a continuous wave (CW) coherent laser source of electromagnetic radiation relies on the focusing properties (the M 2 factor) of the laser to confine the actual measurement volume. The width of the measurement volume is confined by the diameter of the laser beam in the focused region (i.e. the confocal region). The length of the measurement volume along the beam axis is confined approximately by the Rayleigh length of the focused laser beam. For a CW vector velocimeter focused at a distance of one hundred meters from the system, the width of the measurement volume is typically in the order of one millimeter and the length of the measurement volume is in the order of ten meters depending on wavelength and focusing optics (the telescope). For pulsed systems the width of the measurement volume is the same as for the CW laser case, but the length of the measurement volume is given by the confocal parameter or the spatial length of the emitted pulse, whichever is the smallest.
The object in the measurement volume illuminated by the measurement beam may comprise one or more particles, molecules, atoms, or aerosols, such as water droplets, dust, etc., in the measurement volume, each of which scatters, diffracts, reflects, or refracts electromagnetic radiation in response to being illuminated by the measurement beam, thereby forming signal radiation emitted from the object in the measurement volume in response to the illumination by the measurement beam.
Throughout the present disclosure, the teen “particles” includes aerosols, molecules, atoms, dust, etc.
In the following, the part of the signal radiation that is received by a detector of the vector velocimeter is termed a signal beam.
The object in the measurement volume may also be an object of a size similar to the width of the measurement volume; or larger, and the surface of the object may scatter, diffract, reflect, or refract electromagnetic radiation in response to being illuminated by the measurement beam, thereby forming signal radiation emitted from the object in the measurement volume in response to the illumination by the measurement beam. Hereby, the vector velocimeter may determine the velocity of the surface of the object, or vibration, or rotation, of the object.
The vector velocimeter also has a reference beam generator that is arranged for emission of a reference beam of electromagnetic radiation at the wavelength of the measurement beam and propagating at an angle relative to the signal beam. The reference beam generator may for example be a beam splitter in which case the source of electromagnetic radiation also generates the reference beam.
In the vector velocimeter, the reference beam and the signal beam are arranged for interfering with each other at one or more detectors of the velocimeter.
Although the use of a collimated reference beam is envisaged, an arbitrary curvature of the reference beam might be useful. In this case, a given curvature will change the axial distance at which a given object will give the best signal. Thus, especially in case of measurement in the atmosphere, a change in reference beam curvature will facilitate the probing of various axial distances.
The vector velocimeter may in one or more embodiments comprise a detector system comprising a first detector arrangement with one or a plurality of detector arrays including a first detector array arranged in such a way that a signal beam emanating from the object together with the reference beam propagating at a first angle relative to the signal beam are incident directly upon a first detector array of first detector elements, wherein each of the first detector elements converts the intensity of the electromagnetic radiation incident thereupon into a corresponding electronic detector element signal. The operation of the detector array is explained in more detail below.
The vector velocimeter may in one or more embodiments comprise a detector system comprising a first detector arrangement with a first optical array of first optical elements arranged in such a way that a signal beam emanating from the object is incident upon the first optical array together with the reference beam propagating at a first angle relative to the signal beam, and wherein each of the first optical elements redirect the incident signal beam and reference beam towards a first detector array of first detector elements. Each of the first detector elements converts the intensity of the electromagnetic radiation incident thereupon into a corresponding electronic detector element signal. The operation of the optical array in cooperation with the detector array is explained in more detail below.
Utilizing a first optical array for directing the interfering signal beam and reference beam onto the first detector array allows one to focus the beams to a narrower area on the first detector elements thereby obtaining higher beam intensity at the first detector elements.
Due to the non-zero angle between the reference beam and the signal beam at the first detector arrangement in the detector system, and due to the fact that the reference beam and the signal beam are mutually coherent beams, an intensity fringe pattern is formed when the signal beam and the reference beam interfere and the intensity distribution of the interference pattern is detected.
More generally, the angle (θ) may be related to the period (Λ) of the detector arrangement and the wavelength of the measurement beam (λ) as λ/(2Λ)<θ<2λ/Λ. At angles below λ/(2Λ), the fringe signal disappears, whereas for angles above 2λ/Λ, the direction information is lost.
The period (Λ) of the detector arrangement in embodiments of the vector velocimeter where the signal beam and the reference beam are incident directly on the first detector array is the width of a detector array unit comprising 1, 2, 3, 4, 5 or more individual detector elements. Normally, the detector array unit comprises 2-4 detector elements.
The period (Λ) of the detector arrangement in embodiments of the vector velocimeter where the signal beam and the reference beam are incident on the first optical array is normally the width of an individual optical element.
The angle between signal beam and the reference beam may therefore be at least 1°, at least 2°, at least 3°, at least 4° or at least 5°. Suitable angle degrees may be between 1-10°.
The detected intensity fringe pattern is formed by alternating dark and bright lines as for example known from a Michelson type interferometer. The fringe distance is determined by the angle between the signal beam and the reference beam on incidence on the first detector arrangement.
Although the fringe pattern is a detected intensity pattern, for example by the eye for visible wavelengths of radiation, the term “fringe pattern” as used throughout the present disclosure, includes the electromagnetic field in a certain area or volume that would cause a fringe pattern of intensity variations to be detected in the event that a detector was positioned in the area or volume of the electromagnetic field in question.
When an object, such as particles, aerosols, a solid surface, etc., moves in the measurement volume in the direction of propagation of the measurement beam, the Doppler effect causes a corresponding movement of the fringe pattern formed by the signal beam and the reference beam in a direction perpendicular to the alternating dark and bright lines of the fringe pattern. Movement in the opposite direction in the measurement volume also leads to movement of the fringe pattern in the opposite direction.
In embodiments of the vector velocimeter where the signal beam and the reference beam are incident directly on the first detector array of the first detector arrangement with a first angle between the signal beam and reference beam, the first detector array are utilized directly for detection of movement of the fringe pattern formed at the first detection array by interference between the signal beam and the reference beam at the first detector array. Each of the first detector elements generates an oscillating electronic detector element signal in response to a fringe pattern moving across the first detector array. Thus, the first detector array is arranged so that the signal beam and reference beam are incident on the first detector array of first detector elements, each of the first detector elements converting intensity of radiation incident thereupon into a corresponding electronic detector element signal. When the fringe pattern of the interfering signal beam and reference beam move across the first detector array, each of the electronic detector element signals will oscillate due to the movement of the fringe pattern on the first detector elements.
In embodiments of the vector velocimeter comprising a first detector arrangement with a first optical array and a first detector array, the first optical array of first optical elements in cooperation with the first detector array are utilized for detection of movement of the fringe pattern formed at the input plane directly in front of the first optical array by interference between the signal beam and the reference beam. A moving fringe pattern is redirected repetitively by the first optical elements towards the first detector array of first detector elements so that each of the first detector elements generates an oscillating electronic detector element signal in response to a fringe pattern moving across the first optical array. Thus, the first optical array and the first detector array are arranged so that the signal beam and reference beam are incident on the first optical elements at a first non-zero angle and redirected by the first optical elements towards the first detector array of first detector elements, each of the first detector elements converting intensity of radiation incident thereupon into a corresponding electronic detector element signal. When the fringe pattern of the interfering signal beam and reference beam move across the first optical array, each of the electronic detector element signals will oscillate due to the repeated redirection of the fringe pattern towards each of the first detector elements.
Further, the vector velocimeter has a signal processor that is configured for generation of a velocity signal corresponding to the velocity of movement of the fringe pattern across the first optical array based on the electronic detector element signals, for example the frequency or other signal properties of the detector element signals. The fringe pattern velocity corresponds to a first velocity component of movement of the object in the measurement volume in the longitudinal direction of the measurement volume.
For example in a vector velocimeter wherein the measurement beam and the signal beam propagate along the same path, but in opposite directions, the longitudinal direction of the measurement volume coincides with the direction of propagation of the measurement beam (and the signal beam), and thus the velocity component determined by determination of fringe pattern movement as described above, is the velocity component of object movement in the direction of propagation of the measurement beam. When direction of fringe pattern movement is determined, the direction of object movement along the direction of propagation of the measurement beam is also determined.
In a vector velocimeter wherein the signal beam propagates in a direction that forms an angle with the direction of propagation of the measurement beam, the fringe distance is still determined by the angle between the reference beam and the signal beam at the detector array in question, but the measurement volume is formed in cooperation by the transmitter optics transmitting the measurement beam towards the measurement volume and the receiver optics receiving the signal beam emitted from the measurement volume so that the longitudinal direction of the measurement volume in this case does not coincide with the direction of propagation of the measurement beam. Instead, the longitudinal direction of the measurement volume forms an angle with the measurement beam and also with the signal beam. This angle is half the angle formed between the measurement beam and the signal beam, and extends in a plane defined by the measurement beam and the signal beam.
Thus, in this case, the direction of maximum Doppler shift does not coincide with the direction of propagation of the measurement beam. Instead, the direction of maximum Doppler shift forms an angle with the measurement beam, and also with the signal beam, which is half the angle between the measurement beam and the signal beam and extends in a plane defined by the measurement beam and the signal beam.
When, the measurement beam illuminates more than one particle or a large object with a rough surface in the measurement volume speckles can be formed in addition to the fringe pattern.
If the receiver optics can resolve objects with a size less than the cross-section of the measurement volume in a plane perpendicular to the signal beam then speckles are formed.
Like “fringe pattern”, speckle pattern is a pattern of intensity variations as detected by a detector. For example, when a surface is illuminated with visible laser light, speckles may be observed by the human eye. The speckle pattern appears as a grainy intensity pattern when the intensity is detected, e.g. by the human eye. Surface roughness of the object causes formation of the speckle pattern since surface deviations modify the phase of various parts of the incident electromagnetic field differently, and produces the speckle pattern by mutual interference of various parts of the electromagnetic field as received by the detector.
Like the term “fringe pattern”, throughout the present disclosure, the term “speckle pattern” also includes the electromagnetic field that would cause detection of a speckle pattern (of intensity) with an intensity detector.
When the object moves in the measurement volume in a direction in a plane substantially perpendicular to the signal beam, the speckle pattern in the measurement volume as detected with an intensity detector in a position where a signal beam can be received, moves across the surface of the detector with a velocity and direction corresponding to the velocity and direction of the object in the measurement volume in a direction in a plane substantially perpendicular to the signal beam.
In embodiments of the vector velocimeter with a detector system where the signal beam and the reference beam are incident directly on the first detector array of the first detector arrangement, a second detector arrangement comprising a second detector array of second detector elements may be included into the vector velocimeter, wherein each of the second detector elements converts the intensity of the signal beam (and possibly the reference beam) incident thereupon into a corresponding electronic detector element signal thereby generating an oscillating electronic detector element signal when the speckle pattern formed by the signal beam moves across the second optical array. The reference beam may be overlapped with the signal beam on incidence on the second detector array in order to amplify the intensity of the speckles pattern, but it is not a requirement in order to obtain a speckles pattern. The signal beam and the reference beam may further be incident on the second detector array at an angle.
In embodiments of the vector velocimeter comprising a first detector arrangement with a first optical array and a first detector array, a second detector arrangement comprising a second detector array of second detector elements and a second optical array of second optical elements may be included into the detector system. The second optical array is arranged in such a way that the signal beam is incident upon the second optical array, wherein each of the second optical elements redirects the incident signal beam (and possibly the reference beam) towards the second detector array arranged so that the redirected signal beam from the second optical elements are incident upon the second detector array. Each of the second detector elements converts the intensity of the beam(s) incident thereupon into a corresponding electronic detector element signal thereby generating an oscillating electronic detector element signal when the speckle pattern formed by the signal beam at incidence upon the second optical elements of the second optical array moves across the second optical array. The reference beam may be arranged such that the signal beam and the reference beam overlap and interact when the beams are incident on the second optical array in order to amplify the intensity of the speckles pattern, but it is not a requirement in order to obtain a speckles pattern. The signal beam and the reference beam may be incident on the second optical array at an angle.
Other embodiments of the vector velocimeter incorporate a mixture of the two detector arrangements described above. Thus, a first detector arrangement comprising a first optical array in combination with a first detector array may be used for the detection of the first velocity component and a second detector arrangement wherein the signal beam and the reference beam are incident directly on the second detector array of the second detector arrangement may be used for the detection of the second velocity component. The first and the second detector arrangements may also be interchanged for the detection of the first and the second velocity component, respectively.
The signal processor of the velocimeter is adapted for generation of a velocity signal corresponding to a second velocity component of movement of the object in the measurement volume based on the electronic detector element signals from each of the second detector elements. The second velocity component is substantially perpendicular to the first velocity component.
In order to determine a third velocity component in a direction in a plane substantially perpendicular to the measurement beam, for example perpendicular to the second velocity component, the detector system of the vector velocimeter may further comprise a third detector arrangement comprising a third detector array of third detector elements, wherein each of the third detector elements converts the intensity of the signal beam (and possibly the reference beam) incident thereupon into a corresponding electronic detector element signal thereby generating an oscillating electronic detector element signal when the speckle pattern formed by the signal beam moves across the third detector array. The reference beam may be arranged such that the signal beam and the reference beam overlap and interact when the beams are incident on the third detector array in order to amplify the intensity of the speckles pattern. The signal beam and the reference beam may be incident on the third detector array at an angle, but it is not a requirement in order to obtain a speckles pattern.
The third detector arrangement may further comprise a third optical array of third optical elements arranged in such a way that the signal beam is incident upon the third optical array, wherein each of the third optical elements redirects the incident signal beam (and possibly the reference beam) towards the third detector array of third detector elements arranged so that the redirected signal beam from the third optical elements are incident upon the third detector array. Each of the third detector elements converts the intensity of the beam(s) incident thereupon into a corresponding electronic detector element signal thereby generating an oscillating electronic detector element signal when the speckle pattern formed by the signal beam at incidence upon the third optical elements of the third optical array moves across the third optical array. The reference beam may be arranged such that the signal beam and the reference beam overlap and interact when the beams are incident on the third optical array in order to amplify the intensity of the speckles pattern, but it is not a requirement in order to obtain a speckles pattern. The signal beam and the reference beam may be incident on the third optical array at an angle.
The signal processor is adapted for generation of a velocity signal corresponding to a third velocity component of movement of the object in the measurement volume based on the electronic detector element signals from each of the third detector elements. The third velocity component is substantially perpendicular to the first velocity component.
The first and second optical arrays may be integrated into a single optical array.
The first and third optical arrays may be integrated into a single optical array.
The second and third optical arrays may be integrated into a single optical array.
The first and second and third optical arrays may be integrated into a single optical array.
The first and second detector arrays may be integrated into a single detector array.
The first and third detector arrays may be integrated into a single detector array.
The second and third detector arrays may be integrated into a single detector array.
The first and second and third detector arrays may be integrated into a single detector array.
Examples of optical arrays and detector arrays are disclosed in WO 03/069278, which is hereby incorporated in its entirety by reference.
An optical array may comprise at least three optical elements for mapping of different specific areas of the measurement volume onto substantially the same area of the corresponding detector in space thereby generating an oscillating electronic detector signal caused by phase variations of light emanating from the object moving in the measurement volume. For example, the first optical array may comprise at least three first optical elements. The second optical array may comprise at least three second optical elements and/or the third optical array may comprise at least three third optical elements. Accordingly, each of the first, second and third optical arrays may have at least three first, second, and third optical elements, respectively, for mapping of different specific areas of the measurement volume onto substantially the same area of the first, second, and third optical detectors, respectively, in space thereby generating an oscillating electronic detector signal caused by phase variations of light emanating from the object moving in the measurement volume.
In embodiments of the velocimeter where detector system is such that the signal beam and the reference beam are incident directly on the detector array(s), the formation of an oscillating optical signal emitted by an illuminated moving object can be obtained by
1) Illuminating the object moving in the measurement volume with the measurement beam and allowing electromagnetic radiation emitted by the object in response to the illumination to interfere with the reference beam whereby a moving fringe pattern is formed when movement of the object has a velocity component in the direction of propagation of the measurement beam. The first detector array is positioned so that the moving fringe pattern moves across the first detector array thereby generating an oscillating electronic signal in response to the incident electromagnetic radiation, and in vector velocimeters with second and/or third optical arrays by:
2) Illuminating the object moving in the measurement volume with the measurement beam whereby speckles are formed that move when the object has a velocity component perpendicular to the direction of propagation of the signal beam. The second and third optical arrays are positioned so that the moving speckles move across the second and third detector arrays, respectively, thereby generating respective oscillating electronic signals in response to the incident electromagnetic radiation, respectively.
The direction of the velocity component determined by each of the first, second, and third detector arrays in the embodiment of the vector velocimeter where the signal beam and the reference beam are incident directly on the detector arrays is determined by the orientation of the detector array in question.
In embodiments of the detector system, wherein the detector arrangements comprise optical arrays, the repetitive optical structure of the optical arrays is utilized for formation of an oscillating optical signal emitted by an illuminated moving object by
1) Illuminating the object moving in the measurement volume with the measurement beam and allowing electromagnetic radiation emitted by the object in response to the illumination to interfere with the reference beam whereby a moving fringe pattern is formed when movement of the object has a velocity component in the direction of propagation of the measurement beam. The first optical array is positioned so that the moving fringe pattern moves across the repetitive optical structure of the first optical array and is redirected repetitively onto the first detector array that generates an oscillating electronic signal in response to the incident electromagnetic radiation from the first optical array, and in vector velocimeters with second and/or third optical arrays by:
2) Illuminating the object moving in the measurement volume with the measurement beam whereby speckles are formed that move when the object has a velocity component perpendicular to the direction of propagation of the signal beam. The second and third optical arrays are positioned so that the moving speckles move across the repetitive optical structure of the second and third optical arrays, respectively, and are redirected repetitively onto the second and third detector arrays, respectively, that generate respective oscillating electronic signals in response to the incident electromagnetic radiation from the second and third optical arrays, respectively.
The direction of the velocity components determined by each of the first, second, and third optical arrays is determined by the orientation of the optical array in question in cooperation with the orientation with the corresponding detector array, i.e. the direction between neighbouring optical elements and neighbouring detector elements, respectively.
The optical array may for example comprise a linear array of cylindrical lenses. The focal length of the lenses may be positive or negative. For the sake of explanation, the input plane may be defined in front of the array of lenses, e.g., at a distance equal to the focal length of the lenses and perpendicular to the direction of propagation of the incoming electromagnetic radiation.
The fringe pattern is formed at the input plane when the overlapping reference beam and signal beam interact. The speckle pattern and/or the fringe pattern can be detected at the input plane, e.g. by intensity measurements, caused by variations of the electromagnetic field along the input plane.
When the object moves in the measurement volume, the speckle pattern and/or the fringe pattern move across the input plane with a velocity proportional to the velocity of the object in the measurement volume in the direction of movement corresponding to the orientation of the optical array, i.e. the direction perpendicular to the direction of length of the cylindrical lenses. Each of the individual optical elements, in this example constituted by cylindrical lenses, directs the incoming electromagnetic radiation towards a detector array of detector elements. The electromagnetic radiation that is redirected by the individual optical elements sweeps across the detector array, when the speckle pattern or fringe pattern moves a distance that is equal to the width of an individual optical element across the input plane. This is repeated for each optical element when the speckle pattern or fringe pattern travels across the input plane, and when the pattern has traversed a distance equal to the length of the optical array, i.e. across all of the cylindrical lenses in this example, the redirected electronic radiation has been swept repetitively across the detector array. The average number of sweeps is equal to the number of individual optical elements of the linear array passed by the moving fringe pattern, or, moving speckle pattern during the time it takes the speckle pattern to either decorrelate or to move across the entire optical array. The repeated sweeps cause generation of an oscillating electronic signal by each of the detector elements.
Preferably, the width of the individual optical elements is matched to the fringe distance in the fringe pattern or to approximately 2-3 times the width of individual speckles in the speckle pattern at the input plane in order to generate an electronic detector signal with a large signal to noise ratio. The width of the individual optical elements is determined so that the intensity of the electromagnetic field at a detector element varies between a high intensity when high amplitude parts of the fringe pattern or speckle pattern are aligned with the optical elements and a low intensity when low amplitude parts of the fringe pattern or speckle pattern are aligned with the optical elements.
When a fringe pattern and a speckle pattern both move across the input plane of an optical array, the fringe pattern is preferably arranged with a fringe distance that is significantly different from a characteristic size of the speckles so that the velocity components can be separated by spatial filtering velocimetry, i.e. the velocity component of the fringe pattern can be determined with an optical array with a certain pitch, and the velocity component of the fringe pattern can be determined with an optical array with a different pitch. The pitch or period of an optical array is the distance between individual neighbouring optical elements, e.g. for an array of identical cylindrical lenses, the pitch equals the width of the individual cylindrical lenses.
The frequency of the oscillations of the electronic detector element signal corresponds to the velocity of displacement of the fringe pattern or speckle pattern across the input plane in the direction defined by neighbouring optical elements in cooperation with the direction defined by neighbouring detector elements, divided by the array pitch, i.e. the distance between individual neighbouring optical elements in the direction in question. For an array of cylindrical lenses, the direction is perpendicular to the direction of length of the individual cylindrical lenses, and the orientation of the detector array defined by the direction between neighbouring individual detector elements is aligned with the direction perpendicular to the direction of length of the individual cylindrical lenses.
This principle of operation applies in general to any type of optical array utilized and regardless of whether or not an image of the object in the measurement volume is formed at the input plane or directly at the optical array.
Two-dimensional speckle pattern displacement may be determined with a two-dimensional array of optical elements, e.g. circular lenticular lenses, arranged along perpendicular directions of the array and cooperating with a two-dimensional detector array aligned with the two-dimensional optical array.
The vector velocity meter may further comprise an imaging system, e.g. a lens, for imaging part of the input plane onto the detector elements whereby each of the individual optical elements in combination with the imaging system images specific parts of the input plane onto the same specific area of the detector array. Hereby, points at the input plane that are positioned at the same relative positions in relation to adjacent respective optical elements will be imaged onto the same point of the detector array, whereby the signal-to-noise ratio may be improved. Without the imaging system, there will be a small distance between mapped points at the detector array for corresponding points at the input plane having the same relative position in relation to respective neighbouring optical elements. However, the accuracy of the system may still be sufficient and will depend on the actual size of the system.
The optical array and the imaging system may be merged into a single physical component, such as a moulded plastic component, in order to obtain a further compact system suited for mass production.
The individual optical elements of the optical arrays may interact with light by reflection, refraction, scattering, diffraction, etc, either alone or in any combination, of light incident upon them. Thus, the individual optical elements may be lenses, such as cylindrical lenses, spherical lenses, Fresnel lenses, ball lenses, or phase gratings, amplitude gratings, diffractive gratings, Ronchi rulings, prisms, prism stubs, mirrors, liquid crystals, etc.
The optical array may further be formed by a diffractive optical element, such as holographically produced lenses, etc.
Still further, the optical array may comprise a linear phase grating with a sinusoidal modulation of the film thickness, e.g. in a photo resist film.
In the vector velocimeter, the electronic signals output from the individual detector elements from each of the detector arrays may be combined in order to suppress undesired signal components in the electronic signal output from the detector array in question as also disclosed in WO 03/069278, whereby signal detection is simplified. For example, subtraction may be used to suppress the pedestal of the signal, i.e. a low frequency part of the electronic signal, and also harmonics in the electronic output signal may be suppressed.
Also, the direction of movement of the fringe pattern or speckle pattern may be determined by suitable arrangement of the detector array elements in combination with suitable signal processing, e.g. whereby a quadrature, or substantially quadrature, signal may be obtained, thereby simplifying detection of direction as for example compared to conventional LDA (Laser Doppler Anemometer) or LIDAR systems.
Occurrence of velocity signal drop out may be reduced by provision of a second set of optical detector elements that is displaced in relation to the existing set of detector elements so that a signal that is statistically independent of the other signal may be available from one set of detector elements during absence of a signal from the other set of detector elements. Thus by proper processing of the two signals, e.g. switching to a set of detector elements generating a velocity signal, occurrence of signal drop out is minimized.
It is an important advantage of the vector velocimeter that formation of a fringe pattern by the non-zero angle between the reference beam and the signal beam makes it possible to utilize a compact electro-optical device with the first optical array and the first detector array for determination of movement of the fringe pattern and thereby the corresponding velocity of the object in the measurement volume including the direction of the velocity. Furthermore, optical arrays cooperating with respective further detector arrays can be added for determination of speckle movement in one or two dimensions whereby two-dimensional and three-dimensional velocity of the object may be determined.
For embodiments of the vector velocimeter where the signal beam and the reference beam are incident directly on the detector array, the non-zero angle between the reference beam and the signal beam makes it possible to utilize the even more compact detector scheme for determination of movement of the fringe pattern and thereby the corresponding velocity of the object in the measurement volume including the direction of the velocity directly on the detector array.
Furthermore, additional detector arrays can be added for determination of speckle movement in one or two dimensions whereby two-dimensional and three-dimensional velocity of the object may be determined.
Even further, the utilization of a combined detector array allowing for detection of two or three velocity components by the same detector array makes the velocimeter even more compact.
For all embodiments of the vector velocimeter, this makes the one-dimensional, two-dimensional, or three-dimensional vector velocimeter simple, robust, compact and easy to manufacture.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of the vector velocimeter will become readily apparent to those skilled in the art by the following detailed description of exemplary vector velocimeters with reference to the attached drawings, in which:
FIG. 1 schematically illustrates a conventional LIDAR system,
FIG. 2 schematically illustrates a vector velocimeter according to the invention,
FIG. 3 schematically illustrates the operation of an optical array in cooperation with a detector array,
FIG. 4 is a plot of a detector element signal from the detector array shown in FIG. 3 ,
FIG. 5 is a plot of a signal from a displaced optical detector element having a phase lag in relation to the signal shown in FIG. 4 ,
FIG. 6 is a plot of the difference between the signals shown in FIGS. 4 and 5 ,
FIG. 7 schematically illustrates a simple detector circuit with subtraction of detector element signals,
FIG. 8 is a plot of the output signal provided by the detector circuit shown in FIG. 7 ,
FIG. 9 is a plot of the power spectrum of the signal shown in FIG. 8 ,
FIG. 10 schematically illustrates another detector circuit with subtraction of detector element signals,
FIG. 11 is a plot of the output signal provided by the detector circuit shown in
FIG. 10 ,
FIG. 12 is a plot of the power spectrum of the signal shown in FIG. 11 ,
FIG. 13 schematically illustrates yet another detector circuit with subtraction of detector element signals,
FIG. 14 is a plot of the almost phase quadrature signal provided by the detector circuit shown in FIG. 13 ,
FIG. 15 is a phase plot of the signal shown in FIG. 14 ,
FIG. 16 schematically illustrates still another detector circuit with subtraction of detector element signals,
FIG. 17 is a plot of the phase quadrature signal provided by the detector circuit shown in FIG. 16 ,
FIG. 18 is a phase plot of the signal shown in FIG. 17 ,
FIG. 19 schematically illustrates an exemplary vector velocimeter according to the invention,
FIG. 20 schematically illustrates another exemplary vector velocimeter according to the invention,
FIG. 21 schematically illustrates yet another exemplary vector velocimeter according to the invention,
FIG. 22 schematically illustrates still another example of a vector velocimeter according to the invention,
FIG. 23 schematically illustrates yet, still another example of a vector velocimeter, according to the invention,
FIG. 24 schematically illustrates an exemplary vector velocimeter according to the invention,
FIG. 25 schematically illustrates an exemplary vector velocimeter according to the invention,
FIG. 26 schematically illustrates an exemplary a detector array and detector circuit,
FIG. 27 schematically illustrates another example of a vector velocimeter according to the invention, and
FIG. 28 schematically illustrates the detector array of FIG. 27 in detail.
DETAILED DESCRIPTION
The figures are schematic and simplified for clarity, and they merely show details which are important to the understanding of the operation of the vector velocimeter including non-essential features that may have many alternatives. For simplicity, details that are well-known to the person skilled in the art may have been left out. Throughout, the same reference numerals are used for identical or corresponding parts.
In addition to the exemplary vector velocimeters described more fully hereinafter with reference to the accompanying drawings, the principles of the vector velocimeter may also be applied in further different ways and should not be construed as limited to the examples set forth herein. Rather, these exemplary vector velocimeters are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the vector velocimeter to those skilled in the art.
FIG. 1 schematically illustrates a conventional LIDAR system 1 . A laser 2 emits a first coherent light beam 3 of high spatial and spectral beam quality. A beam splitter 4 divides the emitted light beam 3 into a reference beam 5 and a measurement beam 6 , and imaging optics 7 focuses the measurement beam 6 at the measurement volume 8 . The imaging optics 7 may be a Galilean or Keplerian telescope. When the object 9 constituted by aerosols in the measurement volume 8 are illuminated by the measurement beam 6 , the aerosols back scatter a small amount of light forming a signal beam 10 towards the LIDAR detector 11 . For aerosols, the intensity of the back scattered signal beam 10 is in the order of 1 pW when illuminated by a measurement beam 6 of 1 W.
The signal beam 10 propagates through the imaging optics 7 and is redirected by the beam splitter 4 towards the opto-electronic detector 11 on the surface of which, the signal beam 10 interferes with the reference beam 5 and is mixed with the reference beam 5 in the opto-electronic detector 11 so that the opto-electronic detector 11 outputs an a measurement signal containing spectral components corresponding to the difference frequency between the reference beam 5 and the signal beam 10 . The difference frequency corresponds to Doppler frequency of the moving aerosols 9 in measurement volume 8 relatively to the LIDAR system. By processing the measurement signal using a signal processor, the corresponding speed of the aerosols in the direction of propagation of the measurement beam 6 can be calculated.
In the conventional LIDAR shown in FIG. 1 , the direction of movement of the aerosols 9 along the direction of propagation of the measurement beam 6 is not determined, i.e. the same speed will be measured for aerosols moving with the same speed, but in opposite directions along the direction of propagation of the measurement volume.
Complex and expensive components have to be added to the illustrated LIDAR for provision of determination of the direction of movement of the aerosols, for example frequency shifting components, such as a Bragg-cell, shifting the frequency of the measurement beam 6 or the reference beam 5 .
In the vector velocimeter, this problem is solved in a simple and cost effective way.
The vector velocimeter also provides determination of two-dimensional or three-dimensional velocity vectors.
FIG. 2 schematically illustrates a vector velocimeter 100 in which the reference beam 18 and the signal beam 28 are incident on the detector system 32 forming a non-zero angle 34 , contrary to the conventional LIDAR 1 shown in FIG. 1 wherein the reference beam 5 and the signal beam 10 propagate along the same path and are incident on the detector 11 at an angle of 0 degrees.
The angle (θ) 34 may be related to the wavelength of the measurement beam (κ) and the period (Λ) of one or more detector arrangements 33 included in the detector system 32 as λ/(2Λ)<θ<2λ/Λ. At angles below 2/(2Λ), the fringe signal disappears, whereas for angles above 2λ/Λ, the direction information is lost.
The angle 34 may in one or embodiments be at least 1°, at least 2°, at least 3°, at least 4° or at least 5°. An angle 34 of e.g. 3.3° corresponds to a fringe distance of 15 μm at a wavelength of 850 nm. Suitable angle 34 degrees may be between 1-10°. However, as apparent from the above relation, suitable angle ranges are dependent on the wavelength of the measurement beam 20 .
A laser in a laser assembly 12 , for example as disclosed in WO 2009/046717 A2, emits a first coherent light beam 14 of high spatial and spectral beam quality. A beam splitter 16 divides the emitted light beam 14 into a reference beam 18 and a measurement beam 20 , and an optical transmitter 22 focuses the measurement beam 20 at the measurement volume 24 . The optical transmitter 22 may be a Galilean or Keplerian telescope. When the object 26 , in the illustrated example constituted by aerosols 26 , in the measurement volume 24 are illuminated by the measurement beam 20 , the aerosols back scatter a small amount of light forming a signal beam 28 towards an optical receiver 30 that images the measurement volume 24 onto one or more detector arrangements 33 in the detector system 32 , the operation of which is further explained below.
The angle 34 between the reference beam 18 and signal beam 28 incident at the detector system 32 comprising one or more detector arrangements 33 leads to formation of a fringe pattern 36 of intensity variations overlaying a speckle pattern 38 that is formed by illumination of the object 26 in the measurement volume 24 by the measurement beam 20 . The combined fringe pattern 36 and speckle pattern 38 is illustrated to the right in FIG. 2 showing the intensity pattern as it could be detected at the surface of a detector arrangement 33 in the detector system 32 . The fringe distance is determined by the angle 34 .
The longitudinal direction of the measurement beam is equal to the common direction of propagation of the measurement beam and the signal beam. When the object moves in the direction of propagation of the measurement beam 20 , the fringe pattern 36 shown in FIG. 2 moves in the speckle pattern 38 to the left or right, i.e. perpendicular to the direction of the individual fringes, as determined by the direction of movement of the object in the direction of propagation of the measurement beam 20 . Thus, both speed and direction can be determined.
In case the object 26 moves in the transverse direction, i.e. in a direction perpendicular to the direction of propagation of the measurement beam 20 , the fringe pattern 36 does not move while the speckle pattern 38 will move accordingly following the movement of the object.
In case, the velocity of the object does not have components perpendicular to the direction of propagation of the measurement beam 20 , the speckle pattern 38 will remain in its current position; however, the statistics of phase changes of the signal beam may lead to changed occurrence of speckles also known as “speckle boiling”.
The possible movement of the fringe pattern 36 and of the speckle pattern 38 is determined by the detector system 32 comprising one or more detector arrangements 33 , the operation of which is further explained below, whereby the velocity of the object including the direction of the object may be determined in one, two or three dimensions.
FIG. 3 schematically illustrates the operation of a detector arrangement 33 comprising an optical array 112 and a detector array 125 with detector elements 126 , 128 , 130 . In the illustrated example, the optical array 112 is a linear array 112 of substantially identical cylindrical lenses 118 . f 1 is the focal length of the cylindrical lenses 118 . For the sake of explanation, an input plane 114 is defined at a distance equal to the focal length f 1 of the lenses 118 and perpendicular to the direction 116 of propagation of the incoming light 18 , 28 .
When the object is displaced in the measurement volume (not shown), the intensity pattern in question, i.e. the speckle pattern 38 and/or the fringe pattern 36 , moves correspondingly along the input plane 114 . The individual cylindrical lenses 118 redirect the light 18 , 28 towards a refractive lens 122 having a focal length f 2 and being positioned a distance equal to f 1 +f 2 from the linear array 112 . The lens 122 further refracts the redirected light 120 into light 124 propagating towards detector array 125 having detector elements 126 , 128 , and 130 positioned at the focal plane of lens 122 . In this way, each of the individual lenses 118 of the optical array 112 in combination with lens 122 images the input plane 114 onto the same area of an output plane 115 . The detector elements 126 , 128 , 130 of the detector array 125 are positioned so that their individual surfaces for reception of light coincide with the output plane 115 .
Thus, an area 132 of the input plane is imaged by a respective adjacent lens 118 onto an area 134 of a detector element 128 and corresponding areas 136 that are located at the same relative positions in relation to other respective adjacent cylindrical lenses 118 are imaged onto the same area 134 of the detector element 128 .
It should be noted that the distance between the linear array 112 and the lens 122 is chosen to be equal to f 1 +f 2 in the present example for ease of explanation of the operation of the detector arrangement 33 . However, the detector arrangement 33 operates with any distance between the linear array 112 and the lens 122 . For compactness it may be preferred to set the distance to zero.
Thus, when an intensity feature at the input plane 114 has moved a distance 138 that is equal to the width Λ 0 , i.e. the pitch, of an individual optical element 118 , the corresponding image formed by the combination of lens 122 and the respective cylindrical lens 118 sweeps across the area of the detector array 125 with detector elements 126 , 128 , and 130 . This is repeated for the other cylindrical lenses 118 , and it is seen that when an intensity feature has traversed a number of individual cylindrical lenses 118 of the linear array 112 , the detector elements 126 , 128 , 130 are swept repetitively a number of times equal to the number of individual cylindrical lenses 118 the intensity feature has passed. It is seen that for a regular intensity pattern at the input plane, the width of the individual optical elements, in the illustrated example cylindrical lenses 118 , can be matched to the size of features of the intensity pattern, such as fringe distance or speckle size, for optimization of the signal to noise ratio of the output signal.
Furthermore, the optical array 112 is preferably aligned with the desired direction of movement to be determined. Thus, if the detector arrangement 33 shown in FIG. 3 is used for determination of the velocity of the fringe pattern 36 , the optical array 112 is preferably positioned so that its longitudinal direction is perpendicular to the fringe pattern movement and the size of the individual optical elements 118 is matched to the fringe distance. Likewise, if the detector arrangement 33 is used for determination of the velocity of the speckle pattern 38 in a certain direction, the optical array 112 is preferably positioned so that its longitudinal direction is aligned perpendicular to the desired direction of speckle pattern movement and the size of the individual optical elements 118 is matched to approximately 2-5 times the speckle size. If the detector arrangement 33 is used for determination of the velocity of both the fringe pattern 36 and the speckle pattern 38 in e.g. the same direction the system is designed so that the speckle size is an order of magnitude larger than the fringe distance. In this way, fringe pattern movement and speckle pattern movement in various directions can be separated by spatial filtering velocimetry provided by the optical array 112 .
The frequency of the signal generated by each of the detector elements 126 , 128 , 130 corresponds to the velocity of the intensity pattern in question in the direction Δx along the length of the linear optical array 112 divided by the array pitch, i.e. the distance between individual neighbouring optical elements.
The lens 122 is not required in the detector arrangement 33 . In a detector arrangement 33 without the lens 122 , the individual mappings of the input plane 114 onto the output plane 115 by the individual optical elements 118 of the optical array 112 will be displaced slightly with respect to each other. The amount of displacement depends on the size of the detector arrangement 33 ; however, the assembly still operates substantially according to the principles explained above.
The same principle of operation applies in general to other detector arrangements 33 regardless of the type of optical element utilized and regardless of whether or not an image of the object is formed at the input plane 114 .
FIG. 4 is a plot of the output signal 150 from one of the detector elements 126 , 128 , 130 shown in FIG. 3 . A corresponding signal 152 from an adjacent detector element is shown in FIG. 5 . This signal 152 is phase shifted in relation to the signal 150 shown in FIG. 4 because of the physical displacement of the detector elements 126 , 128 , 130 . Since the low frequency pedestals of the two signals 150 , 152 are substantially identical, the difference between the two signals 150 , 152 is an AC-signal 154 as shown in FIG. 6 .
FIG. 7 shows a detector array 125 with six detector elements that are combined two by two for generation of an output signal 150 . As explained above, the detector array 125 is swept once for each passage of an intensity pattern across an individual optical element 118 of the optical array 112 . Thus, neighbouring detector elements of the detector array 125 output signals with a 60° phase shift with relation to each other, and the first element and the fourth element of the detector array outputs signals with a 180° phase shift with relation to each other. In FIG. 7 , a detector circuit configuration is used, wherein the output signals from the first two elements are combined, and FIG. 8 shows a plot of the resulting signal 150 and FIG. 9 shows the power spectrum 156 of the signal 150 . It should be noted that the low frequency part 158 and the second harmonic 160 of the spectrum 156 are quite significant. The low frequency noise leads to a variation of the running mean value which will introduce significant errors in velocity determinations based on zero-crossing detection. The width of the detector has been selected for optimum suppression of the third harmonic of the fundamental frequency. The detector element is assumed to have a rectangular shape and thus, the power spectrum of the detector function is a sinc-squared function. In order to eliminate every third harmonic of the detector output signal, the width of each detector element is selected to be substantially equal to one third of the full width of the detector array that is selected to be equal to the width repetitively swept by an intensity pattern traversing the input plane.
In FIG. 10 , a detector circuit for elimination of the low frequency pedestal is shown. The distance between the two pairs of combined elements corresponds to a phase shift of 180°. The output signals from the detector elements are combined for suppression of the low frequency part of the signals and the even harmonic frequencies of the fundamental frequency. The difference signal 154 is plotted in FIG. 11 , and the power spectrum 156 is plotted in FIG. 12 . The suppression of the low frequency part 158 and the second harmonic 160 is clearly demonstrated by comparison with FIG. 9 .
An almost-phase-quadrature detector circuit configuration is shown in FIG. 13 , wherein output signals from six detector elements of equal size are combined to form two signals 154 a , 154 b in which the low frequency pedestal has been removed. The two signals 154 a , 154 b are 60 degrees out of phase and therefore suitable for determination of the direction of the velocity of the intensity pattern. In this configuration, an exact phase quadrature cannot be achieved without changing the detector width 106 thereby reducing the suppression of the third harmonic. The almost-phase-quadrature signals 154 a , 154 b are plotted in FIG. 14 , and FIG. 15 is a phase plot 162 of the signals 154 a , 154 b . The phase plot 162 has an elliptical shape which facilitates determination of the direction of the intensity pattern velocity.
The detector circuit configuration shown in FIG. 16 provides a substantially exact phase-quadrature detector arrangement, wherein output signals from four detector elements of equal size are combined to form two signals 154 a , 154 b in which the low frequency pedestal has been removed. The two signals 154 a , 154 b are 90° out of phase and therefore suitable for determination of the direction of the velocity of the intensity pattern. FIG. 17 is a plot of the phase-quadrature signals 154 a , 154 b , and FIG. 18 is the corresponding phase plot 162 . The phase plot 162 is circular facilitating determination of the direction of the object velocity and sub-radian measurement accuracy. The circular shape of the traces in the phase plot makes this configuration robust against noise.
FIG. 19 schematically illustrates a vector velocimeter 100 wherein a laser in a laser assembly 12 , for example as disclosed in WO 2009/046717 A2, emits a first coherent light beam 14 of high spatial and spectral beam quality. A beam splitter 16 divides the emitted light beam 14 into a reference beam 18 and a measurement beam 20 , and an optical transmitter (not shown) focuses the measurement beam 20 at the measurement volume 24 . The optical transmitter 22 may be a Galilean or Keplerian telescope. When the object (not shown) in the measurement volume 24 are illuminated by the measurement beam 20 , the object, e.g. aerosols, back scatter a small amount of light forming a signal beam 28 towards an optical receiver 30 that images the measurement volume 24 onto an optical array 112 in a detector arrangement 33 also including lenses 122 a , 122 b , and detector elements 126 , 128 . The operation of the detector arrangement is further explained below.
The beam splitter 16 may be formed according to the principles explained in WO 2009/046717 A2, e.g. in connection with FIG. 6 , wherein the light assembly 12 comprises a single mode semiconductor laser the optical output of which is collimated into a linearly TM-polarized beam that is fully transmitted through a polarizing beam splitter. A quarter-wave plate changes the transmitted optical output into a circular polarization state. The quarter-wave plate is slightly tilted to avoid back-reflections to reach the laser. Subsequently, the surface of a partly reflecting reference window back-reflects a certain percentage of the laser optical output. The back reflected beam is transmitted back through the quarter-wave plate where it becomes linearly TE-polarized. This TE-polarized beam is fully reflected by the surface of the polarizing beam splitter and forms the reference beam 18 . In the vector velocimeter 100 , the partly reflecting surface is wedged so that the reference beam 18 forms a first angle 35 a with the signal beam 28 as the signal beam 28 and the reference beam 18 are incident on a first detection arrangement 33 a in the detection system 32 . A main part of the laser optical output is transmitted as circular polarized light through the reference window. The first angle 35 a between the reference beam 18 and signal beam 28 leads to formation of a fringe pattern 36 of intensity variations overlaying a speckle pattern 38 that is formed by illumination of the object 26 in the measurement volume 24 by the measurement beam 20 as explained in connection with FIG. 2 .
In the illustrated vector velocimeter 100 , the signal beam 28 propagates in a direction that forms an angle with the direction of propagation of the measurement beam 20 . The fringe distance is determined by first angle 34 between the reference beam 18 and the signal beam 28 at the detector arrangement 33 , but the measurement volume 24 is formed in cooperation by the transmitter optics 22 (not shown) transmitting the measurement beam towards the measurement volume 24 and the receiver optics 30 receiving the signal beam emitted from the measurement volume 24 so that the longitudinal direction 140 of the measurement volume 24 in this case does not coincide with the direction of propagation of the measurement beam 20 . Instead, the longitudinal direction 140 of the measurement volume forms an angle with the measurement beam 20 and also with the signal beam 28 . This angle is half the angle formed between the measurement beam 20 and the signal beam 28 , and extends in a plane defined by the measurement beam 20 and the signal beam 28 .
Thus, in this case, the direction 140 of maximum Doppler shift does not coincide with the direction of propagation of the measurement beam 20 . Instead, the direction 140 of maximum Doppler shift forms an angle with the measurement beam 20 , and also with the signal beam 28 , that is half the angle between the measurement beam 20 and the signal beam 28 and extends in a plane defined by the measurement beam 20 and the signal beam 28 .
The possible movement of the fringe pattern and/or of the speckle pattern at the input plane (not shown) of the optical array 112 in the detector arrangement 33 is determined based on output signals from the detector elements 126 , 128 in the detector arrangement 33 .
The optical array 112 comprises array elements that in succession redirect features of the intensity pattern towards detector element 126 and detector element 128 , respectively. For example, light and dark areas may in succession be redirected towards the detector elements 126 , 128 thereby forming an oscillating output signal from the detector elements 126 , 128 . The optical array 112 may for example be a linear optical array of prisms. The two sides of each prism refract incoming rays of light towards the two respective detector elements 126 , 128 . The electronic coupling of the detector elements may be performed as explained in connection with FIGS. 5-19 .
Contrary to the detector arrangement 33 shown in FIG. 3 , light is redirected towards the individual detector elements 126 , 128 by an individual lens 122 a , 122 b so that the detector elements 126 , 128 need not be positioned in close relationship to each other.
The vector velocimeter shown in FIG. 20 operates in a way similar to the vector velocimeter of FIG. 19 ; however, in the velocimeter of FIG. 20 , the angle 34 required for formation of the fringe pattern 36 is formed by the beam splitter 16 and the mirrors 17 in such a way that the measurement beam 20 and the signal beam 28 propagate along the same path whereby the optical transmitter 22 and receiver 30 can be combined, e.g. in a Galilean or Keplerian telescope. Further, a compact detector arrangement 33 is used with a common lens 122 for redirecting light towards both detector elements 126 , 128 positioned in closely spaced relationship to each other.
For determination of velocities in two dimensions, a second detector arrangement 33 b comprising a second optical array 112 b , a second lens 122 b , and a second detector array 125 b has been added to the detector system 32 in the velocimeter shown in FIG. 21 already comprising the first detector arrangement 33 a with a first optical array 112 a , a first lens 122 a , and a first detector array 125 a as described in FIG. 20 . The detector system 32 comprises a semi-transparent beam splitter 164 , which divides the signal beam 28 and the reference beam 18 so that one part of the beams 18 , 28 propagate towards the first detector arrangement 33 a and the other part propagate toward second detector arrangement 33 b . The operation of the second detector arrangement 33 b is explained in connection with FIG. 3 . A third detector arrangement 33 c (not shown) may be added to the detector system 32 for determination of velocities in three dimensions, e.g. with an orientation perpendicular to the orientation of detector arrangement 33 b . The signal beam and the reference beam are incident on the first detector arrangement 33 a at a first angle 35 a and are incident on the second detector arrangement 33 b at a second angle 35 b.
FIG. 22 shows a vector velocimeter 100 similar to the vector velocimeters of FIGS. 21 and 22 , but with another detector system 32 comprising an integrated detector arrangement for determination of velocities in three dimensions. The detector system 32 comprises three optical arrays 112 a , 112 b , 112 c with cylindrical lenses. The optical arrays 112 a , 112 b are positioned and sized for detection of speckle movement along orthogonal directions, i.e. the cylindrical axes of lenses of optical array 112 a are perpendicular to the cylindrical axes of lenses of optical array 112 b . The third optical array 122 c is positioned and sized for detection of fringe movement in a direction forming an angle of 45° in relation to the cylindrical axes of both optical arrays 112 a , 112 b thereby minimizing interference of fringe movement with speckle movement on optical arrays 112 a , 112 b , since fringes are aligned with the cylindrical axes of the optical array 112 c . The operation of each pair of optical array and detector array 122 a , 125 a ; 122 b , 125 b ; 122 c , 125 c , respectively, is explained in connection with FIG. 3 . The lenses 122 a , 122 b , 122 c may be combined in a single lens. The electronic coupling of the detector elements may be performed as explained in connection with FIGS. 5-19 .
FIG. 23 shows a vector velocimeter 100 that operates in a way similar to the vector velocimeter of FIG. 22 ; however, the configuration of the optics is different so that the beams propagate out of plane, i.e. the plane defined by the signal beam 28 as redirected by beam splitter 16 forms an angle with the plane defined by the reference beam 18 as redirected by the beam splitter 16 and mirrors 166 , 168 . The detector arrangement is identical to the arrangement shown in FIG. 22 .
FIG. 24 shows a velocimeter 100 , wherein the detector system 32 comprises a semi-transparent beam splitter 164 similar to the one in FIG. 21 , which beam splitter 164 divides the signal beam 28 and the reference beam 18 so that one part of the beams 18 , 28 propagate towards the first detector arrangement 33 a comprising the first detector array 125 a and the other part propagate toward the second detector arrangement 33 b comprising the second detector array 125 b . The signal beam 28 and the reference beam 18 are incident on the first detector arrangement 33 a with a first angle 35 a between the signal beam 28 and the reference beam 18 . Likewise, the signal beam 28 and the reference beam 18 are incident on the second detector arrangement 33 a with a second angle 35 b between the signal beam 28 and the reference beam 18 . The velocities in two dimensions may thereby be determined using detector arrangements 33 a , 33 b with the two detector arrays 125 a , 125 b , respectively. A further detector array (not shown) may be added to the detector system 32 for determination of velocities in three dimensions, e.g. with an orientation perpendicular to the orientation of second detector arrangement 33 b.
FIG. 25 shows a velocimeter 100 , wherein a semi-transparent beam splitter 164 similar to the one in FIGS. 21 and 24 divides the signal beam 28 and the reference beam 18 so that one part of the beams 18 , 28 propagate towards the first detector arrangement 33 a comprising a first optical array 112 a directing the beams at the detector elements 126 a , 128 a and the other part of the beams 18 , 28 propagate toward the second detector arrangement 33 b comprising the detector array 125 b . A further detector arrangement (not shown) may be added to the detector system 32 for determination of velocities in three dimensions, e.g. with an orientation perpendicular to the orientation of second detector arrangement 33 b.
A two-dimensional detector arrangement comprising a two-dimensional detector array 225 bc as shown in FIG. 26 may also be applied instead of adding an additional detector arrangement to the detector system 32 in the embodiment shown in FIG. 25 for determination of the velocity in the third dimension. The two-dimensional detector array 225 bc is constructed such that it enables determination of the second velocity component by using the second detector elements (exemplified by detector element 226 b ) and the third velocity component by using the third detector elements (exemplified by detector element 226 c ) oriented substantially perpendicular in relation to the second detector elements. In this way, the light incident on specific parts 270 a , 270 b , 270 c , 270 d of the detector elements is used both for the determination of the second and the third velocity component. This provides for a compact solution, wherein the double utilization of the light increases the signal-to-noise ratio.
In the shown example of the detector array 225 bc , a detector circuit the output signal 250 a , 250 ′ a , 250 b , 250 ′ b and the difference spectrum 254 , 254 ′ are generated as shown and explained in FIGS. 7-12 . Different signal processing configurations such as those shown and explained in FIGS. 13-18 could also be used.
The detector array 225 bc may in one example be a complementary metal-oxide-semiconductor (CMOS), possibly coupled to a high-resolution CCD (charge-coupled device) camera.
FIG. 27 shows a vector velocimeter 100 , wherein the configuration of the optics before the detector system 32 comprising the detector array 225 abc is similar to the one shown and explained in FIG. 23 . In the detector array 225 abc , shown in detail in FIG. 28 , additional detector elements 226 a has been added to the detector array 225 bc shown and explained in FIG. 26 . The additional detector elements 226 a are for detection of the fringe movement and therefore oriented such that they form a substantially 45 degree angle with the detector elements for detection of the speckle movement (exemplified by detector elements 226 b , 226 c ). This enables determination of velocities in three dimensions using only one integrated detector array 225 abc , and provides for an even more compact solution, wherein the multiple utilization of the light increases the signal-to-noise ratio.
The detector elements (exemplified by detector element 226 a ) used for detection of the fringe are normally high-resolution detector elements.
REFERENCE LIST
1 conventional LIDAR system
2 laser
3 light beam
4 beam splitter
5 reference beam
6 measurement beam
7 imaging optics
8 measurement volume
9 object
10 signal beam
11 LIDAR detector
12 laser assembly
14 first coherent light beam
16 beam splitter
18 reference beam
20 measurement beam
22 optical transmitter
24 measurement volume
26 object
28 signal beam
30 optical receiver
32 detector system
33 detector arrangement
33 a first detector arrangement
33 b second detector arrangement
33 c third detector arrangement
34 angle between signal beam ( 28 ) and reference beam ( 18 )
35 a first angle between signal beam ( 28 ) and reference beam ( 18 )
35 b second angle between signal beam ( 28 ) and reference beam ( 18 )
35 c third angle between signal beam ( 28 ) and reference beam ( 18 )
36 fringe pattern
38 speckle pattern
100 vector velocimeter
112 optical array
112 a first optical array
112 b second optical array
114 input plane
115 output plane
116 direction of propagation of the incoming light ( 18 , 28 )
118 cylindrical lenses
120 redirected light
122 lens
122 a first lens
122 b second lens
122 c third lens
124 light propagation towards the detector array ( 125 )
125 detector array
125 a first detector array
125 b second detector array
125 c third detector array
126 detector element
128 detector element
130 detector element
132 area of the input plane
134 area of a detector element
136 area of the input plane
138 a distance in the input plane
140 longitudinal direction of the measurement volume ( 24 )
150 a first output signal
152 a second output signal
154 difference spectrum
154 a difference spectrum
154 b difference spectrum
156 power spectrum
158 low frequency part of the power spectrum ( 156 )
160 second harmonic part of the power spectrum ( 156 )
162 phase plot
166 mirror
168 mirror
225 bc two-dimensional detector array
225 abc three-dimensional detector array
226 a detector element
226 b detector element
226 c detector element
250 a output signal
250 ′ a output signal
250 b output signal
250 ′ b output signal
254 difference spectrum
254 ′ difference spectrum
270 a part of a detector element
270 b part of a detector element
270 c part of a detector element
270 d part of a detector element
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A vector velocimeter includes a laser emitting a measurement beam with a wavelength λ, for illumination of an object in a measurement volume to create a signal beam, a reference beam generator generating a reference beam, and a first detector arranged such that the signal beam and the reference beam, propagating at a first angle θ relative to the signal beam, are incident thereon. The first detector includes an array of first detector elements to convert the intensity of the interfering signal beam and reference beam incident thereon into an oscillating electronic detector element signal when the fringe pattern formed thereby moves across the first detector array. A signal processor generates a velocity signal corresponding to a first velocity component of movement of the object in the measurement volume in the longitudinal direction thereof based on the electronic detector element signals from each of the first detector elements.
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CROSS-REFERENCE TO RELATED APPLICATION
This regular utility patent application is a continuation of application Ser. No. 09/629,177 filed Jul. 31, 2000 and allowed Jul. 31, 2001, now U.S. Pat. No. 6,347,685, in turn a continuation-in-part of application Ser. No. 09/258,205 filed Feb. 26, 1999, now U.S. Pat. No. 6,095,283, based on Provisional Patent Application Serial No. 60/102,897 filed on Oct. 2, 1998. The disclosure of U.S. Pat. No. 6,095,283 is incorporated herein by reference thereto.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to specific types of handgrip devices, that are adapted for use in combination with ladders for fall protection. The combination of ladder and handgrip arrays comprised of a plurality of parallel handgrip rungs configured in accordance with the present invention forms an opening through which the ladder user can safely pass while horizontally gripping the horizontally disposed handgrip rungs. The characterization “walk-through” includes—depending on the ladder and structure or apparatus to be climbed—all methods of pass-through, including crawling through and the like.
2. Description of the Related Art
A so-called “through” ladder requires a climber getting off at the top to step through, the ladder in order to reach a landing. “Walk-through” fixed ladders are also well known; they typically include a flared section at the top through which the climber walks. See the prior art device in FIGS. 8 and 9 which will be more fully described below.
Fall protection is mandatory through OSHA regulations on fixed ladders over 20 feet tall in general industry and 24 feet tall in construction. The addition of a post of a rail in the center or at the side of the ladder creates an impediment to circumvent so an outside fitting is safer. Ladders could be upgraded by having climbing safety devices installed as extra protection. About half of the ladders in use are less than 20 feet high so such improvements would serve the purpose well if no fall protection exists for these ladders.
One problem with the flared walk-through ladder is that the climber routinely holds a side rail while descending until the moment the flared section is reduced to 16 inches in width. Unless users observe the need to place the hands closer to the body in order to grasp the side rails or rungs on the main body of the ladder, a person will grasp at thin air and will be subject to a fall at that moment if he has transitioned his feet and assumed the location of the handhold by getting a ready to release the other hand.
Moreover, when 2½-3 inch width angle iron is used as the side rail, only a push-pull pinch grip can be made on the side rails and any fall at the walk-through portion of the ladder is likely to be catastrophic in its outcome. In fact, the ability to hold any vertical shape of the side rails sufficiently to regain balance is not possible. The problems with side rail holdings are several.
First, the hand slides down due to the weight of the body. Second, the force of arresting a free fall up to three feet, i.e., the length of the arm, is dynamic. From rope tests, it is known that the maximum force of a moving rope which can be held is 50 pounds and the least is approximately 10 pounds, both far below a person's body weight. These references are found in the ISFP Newsletter of October, 1996.
Third, a swing fall into the side of the ladder produces an impact of the body with the ladder since the body's center of gravity has to move eight inches from center to side because a ladder rung is 16 inches long. If a person is standing far over to the side, then a movement of 16 inches will occur with an even higher swing fall collision which further tends to destabilize the hand grip.
Fourth, some ladder side rails are impossible to encircle with the hand, e.g., three-inch angle irons or two-inch flange I-beams. Because these shapes cannot be encircled with the hand for a good grip, only a pinch grip can be used and no fall arrest is remotely possible. With two-inch or 2½ inch widths, grips are possible but, due to the factors described above, the grip cannot become an effective grasp under foreseeable methods of climbing on these ladders and a catastrophe must necessarily follow, if the climber falls.
Fifth, the ground or surface below a fixed ladder is almost always unyielding, thus providing the maximum possible deceleration upon impact and therefore the greatest injury to a falling worker.
Sixth, ladders constitute the primary cause of injurious occupational falls based on current OSHA statistics. Since these statistics include portable ladders as well as fixed ladders, it is evident that a climber, who loses his balance on a ladder, needs all the help possible to maintain a grasp that can be reasonably effective if a foot were to slip at the most vulnerable transition points on the ladder.
All climbers eventually misstep no matter how well they are trained. Usually, the climber is preoccupied about achieving the purpose for which the ladder is climbed, not the actual climbing of the ladder. Therefore, exposure to fall hazards cannot be expected to be controlled effectively solely by training workers to climb ladders with the utmost attention to human factors and back-up safety features.
Typical of walk-through ladders in the prior art is the fixed ladder illustrated in FIGS. 8 and 9. A lower section of a walk-through ladder L is shown below a surface A which schematically represents a level to which a climber C is ascending from a lower surface G. The ladder L includes side rails 1 with a plurality of round foot rungs 2 . By way of example, each rung 2 can be 16 inches long at a minimum and ¾ to one inch in diameter. Each side rail 1 can be 2½ inches wide by ⅜ inch to ½ inch in thickness or any size or shape which provides a power grip with materials, such as carbon steel or aluminum, being selected appropriately for the ladder length, usage and environment.
As best shown in FIG. 9, the ladder L at its top above the surface A flares outwardly to form a walk-through section W. The architecture of the walk-through section W may vary depending upon requirements. However, the walk-through section W has parallel vertical side rails 21 and 22 forming an opening O generally, in order to meet code requirements, spaced apart at a distance one from the other about 24 to 30 inches.
As it is also seen in FIG. 9, the walk-through opening O is minimally 3½ feet in height. In this case, if the climber C is about 5′8″ tall, the opening O may be about four feet high.
In FIG. 9, the climber C ascends the ladder L normally. As the climber C negotiates his way into and through the opening O, as indicated by arrows R, onto the surface A, the climber's feet may slip. The vertical side rails 21 and 22 of FIG. 8, regardless of shape or configuration, cannot be grasped without great risk of the climber's grip sliding and/or opening up, depending upon the nature of the slip. Furthermore, a free fall can develop from zero to twice the climber's arm length, resulting in an impact on any grip that the climber C may have. In addition, a swing to one side of the ladder L may result in an impact against the side rails 1 of the ladder L. Consequently, the climber's grip cannot be maintained and a hard fall to the surface G below usually occurs, resulting in serious injury or death.
SUMMARY OF THE INVENTION
In the disclosure of U.S. Pat. No. 6,095,283, the teaching of which is incorporated herein by reference thereto, applicant describes an invention relating to a modification of walk-through ladders, namely, providing a second plurality of horizontal grasping rungs associated with the walk-through section which ordinarily does not have any such rungs. These extra rungs are provided for the climber to maintain a continuum of hand grips on the ladder. Such additional rungs are situated above the highest ladder rung. These higher horizontal grasping rungs are easier for the climber to grab and hold than the vertical side rails during passage up into and down from the walk-through section of the ladder, if a foot of the climber slips during such mounting and dismounting of the ladder.
What applicant has found is that the grasping rung system that can be used to advantage in the systems specifically exemplified in U.S. Pat. No. 6,095,283 also have application in combination with ladders found on tank cars, off-road equipment, railcars, marine applications, such as where rope ladders are used for embarkation and debarkation, manholes, ladders, and platforms. The addition of the horizontal grab bars in accordance with the present invention in effect creates a “through ladder” where the climber passes through an opening between two grab bar devices allowing the horizontal grasps/grips to be horizontally grasped/gripped during departure from a ladder top onto a wide array of apparatuses.
Thus, herein invention comprises a ladder having a top end and comprised of a first plurality of rungs defining a first plane. The first plurality of rungs has a top rung having a first end and a second end at the top end of the ladder rungs. The herein invention further comprises a walk-through section at or proximate the top end of the ladder comprising:
(a) a second plurality of parallel handgrip rungs defining a second plane and having top and bottom handgrip rungs;
(b) a third plurality of parallel handgrip rungs defining a third plane and having top and bottom handgrip rungs; said second plane corresponding substantially to said third plane.
The bottom handgrip rung of said second plurality of parallel handgrip rungs is situated proximate the first end of the top rung of said first plurality of rungs at the top end of the ladder and the second plurality of parallel handgrip rungs forms one side of the walk-through section. The bottom handgrip rung of the third plurality of parallel handgrip rungs is situated proximate the second end of the top rung of said first plurality of rungs at the top end of the ladder and the third plurality of parallel handgrip rungs forms the other side of said walk-through section the second and third planes typically are substantially parallel to the first plane; however, as shown schematically in FIG. 20 and FIG. 11, where the ladder is oriented at an angle on the apparatus to be climbed the plane in which the second and third plurality of rungs are situation need not be substantially parallel to the first plane. The walk-through section may be permanently or movably attached to the ladder or structure or apparatus to be climbed.
Thus, where as shown schematically in FIGS. 11 and 20 the ladder is not oriented substantially normal to the surface to which the ladder is affixed; that is, where the climber ascends to a working surface at the top end of the ladder at an angle, the plane of the walkthrough section in which second and third handgrips are attached need not substantially correspond to the plane in which the first plurality of rungs of the ladder are situated.
Indeed, it is preferred that the walk-through section at or proximate the top end of the ladder be oriented substantially normal to the surface to which the climber is ascending.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of an actual walk-through ladder in accordance with the invention.
FIG. 2 is a front elevational view of an actual walk-through ladder in accordance with the invention.
FIG. 3 is a front elevational view of an actual walk-through ladder in accordance with the invention.
FIG. 4 is a front elevational view of an actual walk-through ladder in accordance with the invention.
FIG. 5 is an alternative further design of the present invention.
FIG. 6 is a side elevational view of an embodiment of the present invention.
FIG. 7 is a rear elevational view of an embodiment of the present invention.
FIG. 8 is a schematic perspective view of an embodiment of the present invention.
FIG. 9 is a schematic perspective view of an embodiment of the present invention.
FIG. 10 is a front side elevational view of an embodiment of the present invention.
FIG. 11 is a side elevational view of an embodiment of the present invention.
FIG. 12 is a front side view of the top end of the ladder of the embodiment of the invention of FIG. 11 .
FIG. 13 is a side elevational view of a bunk bed embodiment of the present invention.
FIG. 14 is a front elevational view of the bunk bed embodiment of FIG. 13 of the present invention.
FIG. 15 is a side elevational view of a single grab bar embodiment of the present invention and a side elevational view of a retractable single pole embodiment.
FIG. 16 is a front elevational view of the retractable single pole embodiment of FIG. 15 of the present invention.
FIG. 17 is a side elevational view of a double grab bar embodiment of the present invention.
FIG. 18 is a front elevational view of the double grab bar embodiment of FIG. 17 of the present invention.
FIG. 19 is a perspective elevational view of a removable grab bar embodiment of the present invention.
FIG. 20 is a side elevational view of an embodiment of the present invention.
FIG. 21 is a front elevational view of the top of the ladder of the embodiment of the invention of FIG. 20 .
FIG. 22 is a schematic perspective view of an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, a second plurality of parallel, horizontal grasping rungs 15 are provided in association with the opening O in the walk-through section W of the fixed ladder L, thus allowing a climber C to grab one of the rungs 15 in the same fashion as the grasp enabled by the first plurality of rungs 2 in the lower climbing section of the ladder L.
As seen in FIG. 3, the rungs 15 may be placed outside of the side rails 21 and 22 of the walk-through section W. Thus, the horizontal grasping rungs 15 may be in the same plane as the opening O but affixed to the side rails 21 and 22 and extending outwardly therefrom rather than into the opening O of the walk-through section W.
As seen in FIG. 1, the present invention is applicable to a job-made ladder L by bolting the rungs 15 at one end to vertically oriented uprights 23 and 24 which extend above the surface A and are aligned parallel to the side rails 21 and 22 . Rungs 15 can be either built into new ladders at the time of fabrication or retrofitted to existing ladders.
The purpose of the improvement of the present invention is to provide rung-like grab-bars with spacing similar to the ladder rungs 2 which are further down in the lower section of the ladder L. Thus, the climber C who has the task of climbing up or down the ladder L can do so with greater security by holding onto the horizontal grasping rungs 15 rather than onto the vertical uprights 23 and 24 or the side rails 21 and 22 which cannot be grasped effectively for even short time periods if the climber's feet slip during mounting or dismounting from the walkthrough section W. Dismounting is typically to a landing onto a roof, mezzanine, platform, parapet or other surface A that may be flat or sloped.
The results of a lost grip on the side rails 21 and 22 at the top of the ladder L can be catastrophic with long falls to the ground G or to a lower platform, thus resulting in serious injury or death in many cases each year. This kind of accident can occur even if there is a protective ladder cage (not shown) or if the climber's protection cable (not shown) has been disconnected.
It is preferable that the horizontal grasping rungs 15 associated with the walk-through section W be long enough for the climber's hand, either bare or gloved, to hold preferably 4 to 5 inches and up to 6 inches of the rung 15 . Also, a diameter of about 1.5 inches is preferred for the rungs 15 . Alternatively, rungs 15 of 0.75 inch diameter or other sizes may be welded or bolted for uniformity with the other rungs 2 to meet codes that require this uniformity over ergonomics.
Ordinarily after a slip, the hand of the climber C cannot hold the vertical side rail 21 or 22 long enough to regain his balance. Thus, a power grip is now required in the 1992 ANSI A14.3 Code Section. Such a power grip cannot be achieved with the prior art ladder which use side rail 2 of flat material with dimension of either ⅜″×2″ or ⅜″×2½″.
The preferred material may be galvanized steel, stainless steel, aluminum, fiberglass polymer, or any other sturdy substance capable of holding the human body when the material is bolted onto the ladder L. Improved fastening devices can be used to permit a mechanical attachment without the need to drill holes through the ladder L to attach metal bolts thereto. Instead, a single coupling 25 , shown schematically in the first embodiment in FIG. 1, could be used for easy fitting of the rungs 15 on each side of the opening O to the side rails 21 and 22 of the walk-through section W.
The assembly including the walk-through section W with the horizontal grasping rungs 15 can be bolted together or welded with seamless joints in such a way that the welds will not break under a normal load or through corrosion or by any other reasonably destructive means.
The embodiment illustrated in FIG. 2 recognizes that the codes generally call for the flared walk-through section W at the top of the fixed ladder L to broaden outwardly from the rungs 2 , which have a 16-inch minimum clear width, to the opening O, which has a clear width of 24 to 30 inches. The additional rungs 15 for climbing protection on the ladder L are accommodated in the opening O which is essentially a higher clear space up to 36 inches in width. However, as one skilled in the ladder art will readily appreciate, the opening O may be decreased in width for safety if it is so desired. In the structures and apparatuses illustrated in FIGS. 5, 6 , 7 and 10 - 19 the opening formed by the handgrip arrays is dependent on the structure or apparatus being climbed as well as ladder size and placement.
Because of the capability of the climber C to span 36 inches which is the maximum allowed by the 1992 A14.3 Code Section without loss of gripping power, the present invention is valuable for increasing safety. If an authority determines that the flaring of the walk-through section W is unnecessary for safety and permits the present invention to be placed inside the flared walk-through section W, thereby narrowing the opening O, the improvement can be of great help to the climber C without sacrificing his ability to dismount properly, even if necessary to do edgewise, because of the increased hand grasping power allowed by the invention. Thus, the climber C can remount the ladder L for descent more easily and safely since the spacing and location of the rungs 2 and 15 are uniform for the entire length of the ladder L and the walkthrough section W in FIG. 2 .
The width of a climber's hips ranges from 11.1 to 16.4 inches across the front and a climber's buttocks range from 7.6 to 14.0 inches from front to back according to U.S. Army Mil-Std. 1472C (1980). Tools on the climber's body can add to these dimensions, so fitting in sideways helps minimize the climber's contact with the vertical uprights 23 and 24 in FIG. 1 .
If there are railings 26 as seen in FIG. 4, along the side rails 21 and 22 , a fitting 27 may be added to allow the plurality of rungs 15 to be mounted to the side rails 21 and 22 inside the walkthrough section W. This fourth embodiment helps the climber C to pull himself manually onto the surface A. Conversely for descent, the closer accessibility of the grasping rungs 15 will be helpful for maintaining confidence of gripping power as the climber C turns around to face the ladder L for descent.
This application is specifically directed to other uses for the horizontal grasping rungs 15 as grab bars which are contemplated for any location where a comfortable handhold is needed to support balance, e.g., on machinery, cranes, platforms, and the like. Such contemplated uses are exemplified in part by reference to FIGS. 5, 6 , 7 and 10 to 22 , inclusive. The combination of rung arrays affixed either temporarily or permanently to structures or apparatuses that are climbed using ladders allows the user to obtain the advantage of a “walk-through” opening created by the parallel handgrip arrays which, in turn, provide for horizontal handgripping by the climber as the opening is traversed. The rung arrays may alternatively be affixed to the ladders that are used to climb on or over the involved structures or apparatuses.
It should be apparent to persons of ordinary skill in the ladder art that numerous variations of the preferred embodiments described hereinbefore may be utilized and that, while this invention has been described fully and completely with special emphasis upon preferred embodiments, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. In particular, the architecture of the walk-through section of the present invention can be used advantageously with numerous types of ladders, as will be appreciated by persons of ordinary skill in the ladder art and is not limited to fixed and/or flared walk-through ladders.
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Structures and apparatuses such as tank cars that have ladders associated therewith are disclosed which have, at the ladder top, two arrays of a plurality of horizontal rungs suitable for a climber using a ladder to horizontally grip by hand. The arrays form an opening through which a climber can leave or access the ladder while gripping the horizontal handgrip rungs of the arrays. The cross-section of the horizontal handgrip rungs is substantially round and should not exceed 2 inches in diameter. The preferred cross-section of the rungs is within the range of from about ¾″-1″ in diameter.
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RELATED APPLICATION
This application is a continuation-in-part of our prior application Ser. No. 08/257,352 filed Jun. 9, 1994 and entitled FLEXING SAFETY SHIELD FOR HYPODERMIC NEEDLES; now U.S. Pat. No. 5,591,133.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The apparatus of the present invention relates to hypodermic needles, and more particularly to a shield for hypodermic needles to protect medical personnel and others from accidental contact with needles that may have been exposed to contagious and/or blood-borne diseases.
2. Art Background
Hypodermic needles are indispensable to the health care industry for both drawing bodily fluids from and administering medication to patients. Most hypodermic needles currently in use are disposed of, after one use, in a waste receptacle to limit further contact between medical personnel or patients and the cannulas of the uses needles. Avoiding contact with used needles is essential to prevent the transmission of diseases, particularly blood-borne diseases such as acquired immune deficiency syndrome (AIDS). Although medical personnel are trained to handle used needles with extreme care to avoid exposing themselves, the large volume of unshielded syringes renders such accidental exposure commonplace.
The hypodermic syringes now commonly in use offer insufficient protection against accidental contact with their cannulas after use. The most common hypodermic needle includes a replaceable plastic cap to cover its cannula. The cap is removed just prior to use and is replaced thereafter. The act of replacing the cap exposes medical personnel to the danger of accidental contact, particularly subcutaneous contact, with the used cannula. Moreover, the person administering the needle may forget to replace the cap, or may do so incorrectly, thus increasing the probability of accidental contact between the used cannula and those who must handle medical refuse.
A number of prior art needle shields have been developed in an attempt to solve the problems of accidental exposure and illicit re-use. Many of these devices create a "safe" position with a cylindrical outer sleeve that radially surrounds the cannula such that the cannula is not exposed after use. Many of these designs, however, require that the needle administrator take an affirmative act to place the device in the safe position. These devices suffer from problems similar to those of the common hypodermic needle using a plastic cap. The act of placing the device in the safe position exposes the needle administrator to the danger of accidental contact with the cannula. Moreover, the needle administrator may forget to place the device in the safe position and thus fail to reduce the probability of accidental contact between the cannula and refuse handlers.
Other prior art designs have been developed in an attempt to provide a needle shield that automatically resets to a safe position after the needle is used, thus eliminating the need for an affirmative act by the administrator. These devices also typically employ a sleeve to axially surround the cannula. The cannula is coupled to a spring such that when an axial force of sufficient magnitude is applied by the needle administrator to the syringe, the cannula protrudes from the sleeve to permit injection. The spring develops a reactive axial force in the direction opposite to the applied force. The use of a spring to reset the cannula into the safe position suffers from a major drawback, because the reactive force created by a spring increases as the length of the spring is decreased through compression. Thus, to attain an appropriate depth of insertion in the patient, the needle administrator must apply an increasingly greater force than was required to initially disengage the needle from the safe position. This increasing force will be transmitted to the patient, causing discomfort, and will likely render smooth administration of an injection difficult. This inherent property of springs therefore makes it difficult to solve the problems of inadvertent exposure and unacceptable large resistance during the injection process.
An important prior art concept is that shown in the Alvarez U.S. Pat. No. 4,139,009 issued in 1979. Alvarez employed a plastic sleeve formed into separate longitudinal slats that bow outwardly when an axial force is applied to the forward end of the sleeve. A variation of the Alvarez design is shown in the Kuracina U.S. Pat. No. 4,998,922 issued in 1991.
There is, however, much room for improvement in the art of shielding the handles of hypodermic needles from the cannulas of those needles after they have been used.
SUMMARY OF THE INVENTION
The shield of the present invention is a novel and nonobvious improvement over previous attempts to shield handlers of hypodermic needles from accidental contact with such needles once they are used. The present invention provides a sleeve which is initially configured in a "safe" position. The safe position occurs when the cannula is completely withdrawn inside of the sleeve so that no part of the cannula protrudes from the sleeve. The sleeve's structural characteristics are such that an initial threshold of axial force must be exceeded before the sleeve's initial rigidity is overcome, thereby permitting exposure of the cannula. Once the threshold force is exceeded, the amount of force necessary to further displace the shield of the present invention to expose the cannula to the extent necessary to achieve an appropriate depth within a patient is not substantially greater than (if not less than or equal to) the threshold force, so as to not interfere with the smooth administration of an injection.
According to the invention the needle shield is in the form of a sleeve having longitudinal displaceable portions or slats that hingedly bend at predetermined locations to facilitate their displacement. The threshold axial force is that force necessarily applied to the syringe, with the outer end of the sleeve in contact with the surface to be penetrated, to overcome the initial rigidity of the sleeve and thereby cause the displaceable portions or slats to hinge at the predetermined locations. Once hinging begins, the force necessary for continued displacement of the displaceable portions may actually be less than the threshold force initially required.
During withdrawal of the needle, the elasticity of the sleeve causes the slats or displaceable portions of the sleeve to retract until the sleeve has once again returned to its initially rigid state and the cannula has become completely withdrawn inside of the sleeve. Thus, the shield automatically returns to its "safe" state.
Further according to the invention a locking feature is provided to retain the shield in the safe position. A pair of circumferential flanges are provided at an index location on the sleeve. A slidable collar normally positioned near the inner end of the sleeve may be moved (in a direction opposite to that required to expose the cannula) and locked between the pair of circumferential flanges at the index location on the sleeve. This locking mechanism becomes engaged while the shield is already providing protection via the safe position.
A further preferred feature of the invention is that the collar is flexible, encircles an inner end portion of the sleeve, and is frangibly connected to the inner end portion of the sleeve so that after usage of the needle assembly when the sleeve collapses back to its original shape, the collar may then be detached from the sleeve and slid over one of the flanges so as to occupy a position between the pair of flanges and thereby prevent any subsequent expansion of the sleeve.
It is therefore an objective of the present invention to provide a hypodermic needle shield which requires a threshold axial force, to go from a safe position to an exposed position, that is significantly greater than axial forces typically encountered during most unintentional subcutaneous exposures to used cannulas, but is not so great as to cause abnormal discomfort to a patient during initial insertion.
It is further an objective of the present invention to provide a hypodermic needle shield that, once the threshold force has been exceeded, the force necessary for continued displacement of the shield is less than that which would cause disruptive interference with the injection process.
It is still further an objective of the present invention to provide a hypodermic needle shield which when withdrawn from the patient returns immediately to the safe position.
It is still further an objective of the present invention to provide a hypodermic needle shield which has a locking feature that discourages illicit use after disposal and greatly increases the force necessary to overcome the safe position and to expose a used cannula.
These and other objectives of the present invention will become apparent in light of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a hypodermic needle assembly in conjunction with the needle shield of the present invention.
FIG. 2 illustrates the needle shield of the preferred embodiment of the present invention in the safe position.
FIG. 3 is an exlarged longitudinal cross sectional view along lines A--A of FIG. 2.
FIG. 4 is an enlarged and exploded fragmentary cross-sectional view of a hinging portion that joins displaceable portions of a sleeve of the present invention.
FIG. 5 illustrates the needle shield of the preferred embodiment of the present invention in an open position.
FIG. 6 illustrates a longitudinal cross-sectional exploded view of a hinging portion that joins a displaceable portion of the sleeve with a radially rigid portion of the sleeve.
FIG. 7 illustrates an alternate embodiment of the sleeve of the present invention in an open position.
FIG. 8 illustrates another alternate embodiment of the sleeve of the present invention in an open position.
FIG. 9 illustrates the shield of the present invention in a safe and locked position.
FIG. 10a illustrates channels that may be employed to divert excess blood from a cannula.
FIG. 10b illustrates the channels as a cross-sectional view through lines A--A.
FIG. 11a illustrates a hypodermic needle in conjunction with the needle shield of the present invention being administered to a patient.
FIG. 11b illustrates a hypodermic needle and shield of the present invention as the needle is being filled from a vial.
FIG. 12a illustrates the needle shield of the present invention in the safe position.
FIG. 12b illustrates the needle shield of the present invention in the exposed position under use.
FIG. 12c illustrates the needle shield of the present invention in the safe and locked position.
FIG. 13a is an enlarged fragmentary longitudinal view, partially in cross-section, illustrating the frangible connection of the slidable collar to the flexible sleeve.
FIG. 13B is a transverse cross-sectional view taken on line A--A of FIG. 13A and further showing both the frangible fingers supporting the collar and the fluid channels.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a hypodermic needle assembly 2 in conjunction with the needle shield of the present invention. As shown in FIG. 1, the hypodermic needle assembly 2 includes a syringe barrel 4 housing a portion of a plunger 6. The barrel 4 is coupled to a hub 14 which is coupled to a cannula 8. The needle has a base end, a main portion, and a tip end. As shown in FIG. 1, the needle shield of the present invention includes a cylindrical sleeve 10 which is also coupled to the hub 14.
The sleeve 10 may include a thin membrane at the tip of the sleeve toward the tip end of cannula 8. The membrane would be broken as the cannula 8 protrudes from sleeve 10, such as during insertion into a patient or vial. The membrane can serve several purposes, including hermetically sealing the cannula until a first use. The membrane can also be used to contribute towards the initial threshold force necessary to cause exposure of the cannula. Even after the membrane has been initially pierced, it can continue to provide resistance to axial displacement of the sleeve, thereby contributing towards the requisite threshold force.
The cylindrical sleeve 10 may be coupled to a hub 14 of any size or shape. Further, the sleeve 10 could be manufactured with the hub 14 as one piece. Thus, the needle shield of the present invention may be manufactured to operate with any existing line of hypodermic needles, or it may be customized for integrated manufacture. The manufacturer also has the option to retain the existing overcap and packaging for the needle.
In the preferred embodiment, the sleeve 10 is made from POLYPROPYLENE. The sleeve may also be made of JDPE, LDPE, DELRIN, NYLON or any materials providing the desired mechanical characteristics as disclosed herein.
FIG. 2 illustrates the needle shield of the present invention in the safe position, the cannula 8 being then completely housed within the cylindrical sleeve 10. FIG. 3 illustrates a longitudinal cross-sectional view taken along lines A--A of FIG. 2. The cylindrical sleeve 10 is preferably a unitary plastic member that defines an axially extending central bore 22 to slidably receive the cannula 8. The cylindrical sleeve 10 includes a radially rigid outer end portion 10a which is at least coextensive with the tip of the cannula when the shield is in the safe position, a radially rigid inner end portion 10d, and displaceable portions 10b and 10c. In the preferred embodiment, the displaceable portions or slats 10b and 10c are formed by creating two slits 12 along the length of the cylindrical sleeve 10 between outer end portion 10a and inner end portion 10d. The slits 12 are preferably separated by 180 degrees around the sleeve 10. Thus, each end portion 10a, 10d is preferably cylindrical in shape while the slats 10b, 10c are semi-cylindrical.
Displaceable portions or longitudinal slats 10b and 10c, each has two subportions. One subportion of the displaceable portion or slat 10b is hinged at or adjacent to its interface with the outer end portion 10a of the sleeve at 31, while its other subportion is hinged at or adjacent to the interface with the inner end portion 10d of the sleeve at 27. In similar fashion one subportion of the displaceable portion or slat 10c is hinged at or adjacent to its interface with the outer end portion 10a of the sleeve at 30, while its other subportion is hinged at or adjacent to the interface with the inner end portion 10d of the sleeve at 26. At a longitudinal mid-region of the sleeve 10 the two subportions of slat 10b are hinged at 25, and the two subportions of slat 10c are similarly hinged at 24 at the longitudinal mid-region.
The slits 12 may completely sever the cylindrical sleeve 10, or may be formed such that a thin layer of plastic remains along the length of the slit. It will be appreciated by those of skill in the art that more than two slits may be formed in sleeve 10 and that the slits may be arranged at various angles around the sleeve 10 to attain the desired initial rigidity characteristics of the sleeve 10, as well as the desired force vs. displacement response of the sleeve once the threshold has been exceeded. The number of slits will of course govern the number of subportions making up each displaceable portion 10b and 10c.
FIG. 4 illustrates an enlarged and exploded longitudinal cross-sectional view of the longitudinal mid-region of sleeve 10, although circumferential flanges 16 are not shown here. In one preferred embodiment, hinges 24, 25 are formed by creating a triangular indentation 28 in the cylindrical sleeve 10. The base of the triangular indentation is the edge of the sleeve formed by the slit. The indentation can be formed during the manufacturing of the sleeve 10, or by deforming or cutting the material comprising sleeve 10.
The hypodermic needle assembly 2 remains in the safe position until a sufficiently large reactive axial force is created at outer end portion 10a of the sleeve 10, as shown in FIG. 3, to overcome the initial rigidity of sleeve 10. The axial force on outer end portion 10a results from the needle administrator placing the tip end of the sleeve 10 in contact with the patient and applying force to the needle assembly 2. The axial force is the reaction force created by the patient's body and is transmitted axially along the sleeve 10 and applied along the sides "a" of the triangular indentation 28 of the hinges 24, 25 as shown in FIG. 4. The force on side 28a creates a torque around an apex 28c of the triangular indentation 28. Additionally, the axial force applied to the apex 28c creates a torque around hinges 30, 31, and 26, 27. Because the plastic sleeve 10 does not substantially deform axially, the axial force is opposed by an equal axial force directed opposite to the applied axial force.
When the applied axial force exceeds a threshold axial force dictated by the geometry, dimensions and materials of the sleeve 10, the resulting torque causes the subportions of displaceable portions or slats 10b and 10c of the sleeve 10 to be displaced radially away from the cannula 8 about hinges 26, 27 and 30, 31. Once the threshold axial force has been exceeded, very little additional force (if any) is necessarily applied to needle assembly 2 to cause further displacement of displaceable portions 10b and 10c. This is because relatively little compression of hinges 24, 25, other than that caused by the threshold axial force, results from the radial displacement of the subportions of slats or displaceable portions 10b and 10c of the sleeve 10.
FIG. 5 illustrates sleeve 10 after an axial force exceeding the threshold has been applied. The displacement of the subportions of displaceable portions 10b and 10c of sleeve 10 allows the axial force to slidably move outer end portion 10a of the sleeve 10 axially along cannula 8, thereby facilitating insertion of the cannula 8 into the patient.
When the axial force is removed, such as when the cannula 8 is withdrawn from the patient, the compression force in hinge 28 creates a torque which causes the subportions of displaceable portions 10b and 10c of the sleeve 10 to return radially inwardly toward the cannula 8. This movement causes radially rigid outer end portion 10a to slide axially toward the tip of cannula 8 until the sleeve 10 reverts to the safe position as shown in FIG. 2 (i.e. rigid portion 10a is at least coextensive with, if not extending beyond, the tip end of cannula 8). Because most hypodermic needles currently in use are disposed of after one injection, fatigue of hinge 24 should not be a factor in preventing a compressive force from restoring the sleeve 10 to the safe position. The shield of the current invention may be optimized for use with hypodermic needles that are used numerous times, such as for catheters, if a suitable material is chosen for hinges 24, 25.
As illustrated in FIG. 3, hinges 26, 27 and 30, 31 allow the subportions of slats 10b and 10c, respectively, to be radially displaced once the threshold axial force has been exceeded. Hinges 26, 27 may be implemented by forming slots 100, 102 in sleeve 10, as shown in FIG. 6. Hinges 30, 31 may be implemented in the same manner. Alternatively, if an increase in the initial rigidity is desired, no slots need be formed, and hinges 26, 27 and 30, 31 can be left to flex due to the inherent flexibility of the material from which sleeve 10 is made.
As shown in FIG. 5, in the preferred embodiment, hinges 26, 27 and 30, 31 exert equal axial forces to the slats 10b and 10c such that the subportions of slats 10b and 10c are radially displaced substantially equally from the cannula 8 upon application of an axial force that exceeds the threshold.
The needle shield of the present invention as shown in FIG. 2 may be locked in the safe position to further increase the amount of axial force required to cause accidental exposure of the cannula 8, as well as to make illicit use after disposal difficult. FIG. 9 illustrates the needle shield of the present invention in a locked position. A collar index 16 consists of a first circumferential flange 16a, 16c, and a second circumferential flange 16b, 16d. As illustrated in FIG. 9, a collar 18 is disposed within the two flanges of this index to further resist displacement of the displaceable portions or slats 10b and 10c of the sleeve 10.
As illustrated in FIG. 3, the slat or displaceable portion 10b nearest the outer end of the sleeve 10 is preferably formed integrally with both of the circumferential flanges 16a, 16c, and 16b, 16d. The flanges forming collar index 16 vary in diameter such that in the cross-sectional view of FIG. 3, the borders or edges of the flanges appear as four right triangles 16a, 16b, 16c and 16d. The border of flange 16b, 16d facing toward inner end 10d of the sleeve 10 rises from a minimum value at a base point nearest the inner end of the sleeve to a maximum value at a point closer to the tip of the cannula 8.
As shown in the safe position of the needle shield in FIG. 1, the collar 18 is normally disposed at the inner end of sleeve 10 away from the tip of the cannula 8, and forms a diameter that is preferably just greater than that of the sleeve. To lock the shield, the needle administrator slides the collar 18 axially along the portion 10d of sleeve 10, past the hinges 24, 25, and partly over the slat 10b toward flange 16b, 16d. It will be noted that this is a direction opposite to that typically associated with accidental exposure to a used cannula. As the collar 18 is slid toward and engages the flange 16b, 16d, its diameter stretches slightly because of a distributed radial force created by the increasing diameter of the flange. The collar 18 stretches sufficiently to slide over the flange 16b, 16d, and then occupies the longitudinal space on the sleeve 10 between the two flanges 16b, 16d, and 16a, 16c. Once located between the two flanges in collar index 16, the collar resumes its normal diameter. Further axial movement of the collar 18 in either direction is then prevented by the two circumferential flanges.
In the locked position, if an axial force is applied to the sleeve 10 as illustrated in FIG. 3, the collar 18 prevents displacement of the displaceable portion or slat 10b of the sleeve 10 by applying a force, directed radially inward toward the cannula 8, to the displaceable portion 10b of the sleeve 10. If the collar 18 is made of sufficiently rigid material, the collar 18 will restrict radial movement of the slat 10b of the sleeve 10, even for large axial forces applied to the sleeve 10. Of course, collar 18 must be flexible enough to be stretchable over the flange 16b, 16d.
While the needle administrator slides the collar 10, the cannula 8 remains completely housed within the sleeve 10 in the safe position. The operation of sliding the collar 18 towards the tip end of cannula 8 presents little risk of accidental exposure to the cannula 8. Should the needle administrator neglect to lock the shield in the safe position, accidental exposure to the cannula 8 is still prevented provided no axial force exceeding the threshold is applied. FIGS. 12a, 12b and 12c illustrate the shield of the present invention in the safe, the open, and the locked positions, respectively.
The collar index is designed to permit stretching of the collar such that the collar can be slipped over the border forming the index to engage the index. Once engaged, the collar snaps back to its original diameter and cannot be disengaged from the index. In this "locked" state, a force which greatly exceeds the threshold force of the "safe" position is required to expose the cannula because the collar prohibits displacement of the displaceable portions of the sleeve. Further, it discourages illicit use of the discarded needle by making exposure of the cannula extremely difficult.
FIGS. 7 and 8 illustrate alternate embodiments of the hypodermic needle shield of the present invention. In the embodiment illustrated in FIG. 7, a hinging portion 60 of the sleeve 66 towards the tip end of cannula 64 provides a greater force than a hinging portion 62 away from the tip of the cannula 64. The unequal forces cause the forward end of sleeve 66 to move into the position as shown in FIG. 7.
Conversely, in the embodiment illustrated in FIG. 8, a hinging portion 68 of sleeve 70 towards the tip end of cannula 72 provides less force than a hinging portion 74 away from the tip end of cannula 72. The unequal forces cause sleeve 70 to move into the position as shown in FIG. 8. One or the other of these embodiments may be preferable depending on the geometry of the surface to which the cannula 64 or 72 is to be applied.
If hinging portions 26, 27 (and 30, 31) are implemented by forming slots 100, 102 as illustrated in FIG. 6, the hinging portions may be manufactured to present unequal reactive forces by forming a slot of greater length for one hinging portion than another; each hinging portion will provide a resistance to motion that is inversely proportional to the length of the associated slot. Alternatively, one hinging portion may include a slot while the other hinging portion does not include a slot. The hinging portion implemented with a slot will present less resistive force than the hinging portion not including a slot. Alternatively, hinging portions may be implemented by forming angled slots to influence the direction of displacement.
In another embodiment, hinging portions may provide unequal forces by narrowing the sleeve 10 at one hinging portion either more or less than at the other hinging portion. The hinging portion formed at the narrower part of the sleeve 10 will provide less resistive force than the other hinging portion. Finally, in a unitary sleeve is not employed, hinging portions may be manufactured to provide unequal forces by using different materials to form the different hinging portions.
Those of skill in the art will recognize that there are many variables in the manufacturing process that can be altered to achieve different performance points. Rigidity and elasticity of the materials used to form the sleeve, the dimensions of the sleeve, the characteristics of the hinging portions, the number of subportions into which the displaceable portions are divided, etc. can all be varied to produce a different threshold of displacement forces, different force versus displacement characteristics, and the amount of compressive force available to return the sleeve to a safe position after withdrawal of the applied axial force from the shield. The preferred embodiment is disclosed as being unitary in nature, i.e., axially rigid portions 10a, 10d, displaceable portions 10b, 10c and hinging portions 24, 25, 26, 27, 30 and 31 are all of integrated construction. It is conceivable, however, that some or all of the components of sleeve 10 can be separate and distinct. Of course, the hinging portions can be made out of more commonly known hinge mechanisms. So long as the above-contemplated variations of the preferred embodiment provide the desired characteristics: 1) an initial threshold force that must be exceeded for displacement of the sleeve can begin; 2) a force versus displacement curve that does not greatly exceed the threshold force over the desired range of displacement, and 3) a sufficient compressive force in the hinging portions of the sleeve to return the sleeve to the safe position upon removal of the force, these variations will fall within the intended scope of the present invention.
The invention thus provides a hypodermic needle that will not be exposed unless a force is applied that exceeds some threshold. Unlike prior art devices, particularly those using springs, once the threshold force is exceeded, little additional force (if any) is required to cause further displacement of the shield and thus further exposure of the cannula 8. As shown in FIG. 11a, when a needle administrator applies the threshold force against a patient, the cannula 8 is inserted into the patient. The same is true when withdrawing drug from a vial as shown in FIG. 11b. When the needle administrator stops applying an axial force and withdraws the cannula 8 from the patient, the cannula retracts into the sleeve 10. Once the cannula 8 is completely withdrawn from the patient, the cannula 8 is completely retracted into the sleeve 10 and the hypodermic needle shield is again in the safe position. Thus, the tip of the cannula 8 is exposed to the patient only during insertion and withdrawal of the needle, protecting needle administrators and others from accidental exposure to the tip of cannula 8.
To help prevent exposure to blood adhering to the cannula 8 as a result of insertion into a patient, one or more channels 62 and 64 may be formed in the sleeve 10 as shown in FIGS. 10a and 10b. As the anterior or forward end of the sleeve 10 moves along the cannula 8, excess blood will tend to gather inside the channels 62 and 64 rather than being forced outward through the end of sleeve 10.
In addition to the previously mentioned benefits, the needle shield of the present invention is easier to manufacture than prior art needle shields. Prior art needle shields typically contain many moving pieces. The hub 14 and the sleeve 10 of the present invention may be manufactured as a single unitary piece by a simple molding process, requiring only the recurring of an existing mold cavity. The cannula is inserted after the molding process and attached in the normal manner with, at most, a few minor modifications. The collar 18 and the collar index 16 may also be assembled with the hub 14 and the sleeve 10 during the molding process. Thus, the shield of the present invention may be manufactured by a simple molding process that avoids expensive assembly procedures.
According to the presently preferred form of the invention the collar 18 is made integral with the other parts of the needle shield. As shown in FIGS. 13a and 13b, the collar 18 is essentially in the form of an annular band with its interior wall surface spaced slightly away from the wall of the sleeve. At three points spaced 120 degrees around its circumference the collar 18 is frangibly connected to the sleeve 10d by means of small fingers 18a, 18b, 18c. These fingers are formed in the molding process, along with the sleeve and the collar itself. In operation, the size and strength of the fingers are sufficiently small that the collar can be separated from the sleeve, and slid toward the slat 10b, all as previously described.
The present invention may be manufactured using other efficient techniques. For example, the needle shield of the present invention may also be coupled to existing hypodermic needle hubs by heat sealing or sonically melting the sleeve 10. Thus, an existing hypodermic needle manufacturer need not redesign a needle assembly to operate in conjunction with the shield of the present invention.
The invention has been described in conjunction with numerous preferred embodiments. Numerous alternatives, modifications, variations and uses will be apparent to those skilled in the art in light of the foregoing description. For example, the indentation of hinging portions 24, 25 may be formed of shapes other than a triangle, such as a semi-circle. Also, instead of being formed by an indentation, hinging portions 24, 25 may be formed by joining subportions of displaceable portions 10b and 10c at an angle. Similarly, hinging portions 26, 27 and 30, 31 need not be implemented with slots. The shield of the present invention need not be formed as a unitary sleeve and many materials, other than those disclosed herein, will be recognized by those of skill in the art as suitable for constructing the sleeve.
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A shield for a hypodermic needle assembly includes a hollow plastic sleeve with an elongated main portion adapted to normally enclose the main portion of a needle, a slidable outer end portion which normally extends beyond the tip end of the needle, the elongated main portion of the hollow sleeve responding to an axial force on the outer end portion for expanding radially outwardly to retract the end portion of the sleeve and expose the needle tip end, a spaced pair of circumferential flanges formed on the elongated main portion of the sleeve, and a flexible collar encircling the sleeve and slidable over one of the flanges so as to occupy a position between the flanges and thereby prevent subsequent expansion of the main portion of the sleeve.
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BACKGROUND OF THE INVENTION
During the regular life cycle of code development and testing, the testers execute based on provided test cases (detailed step-by-step instruction of how and what to test). The main course of executing test cases is to check for the existence of defects or errors in a program, project, or product, based on some predefined instructions or conditions.
One of the embodiments of this invention is generally directed to the need to group all related logs and traces, and provide them to the developers, in order for them to investigate, understand, and fix the problem.
When issues and problems occur during the testing, the testers communicate those issues to the developers. In large teams and/or for the purpose of tracking such issues, the information is recorded and tracked through a bug tracking system accessible to the developers. Testers often do not know which logs and traces need to be grouped and provided to the developers, in order for them to investigate, understand, and fix the problem.
In addition to the regular testing observations, the developers may need to have access to the logs and traces (i.e. detailed application and system generated information) generated during the test case execution on the test environment/machines.
Most of the defects cannot be understood simply by describing the steps performed by the tester, during testing phase due to timing, synchronization, concurrency, and others issues. There is also a possibility that the problem may not be reproduced on the next try either, by the developer during code fix, or by the tester during execution of the test cases. Consequently, the testers often need to repeat the test cases in order to provide the correct documentation and data to the developers.
SUMMARY OF THE INVENTION
An embodiment of the invention is to provide a tool that defines and uses the concept of “Logs/Traces Profile” and “System Logs/Traces Profile” (comprising of a role and the log and trace file locations), incorporates them within the test design document, and associates the Role(s) to individual test cases, within the document.
These “Logs/Traces Profile” is an object that includes, for example, a list of log and trace files and a role associated with a machine in the test environment. “System Logs/Traces Profile” is a set of “Logs/Traces Profile” objects identifying each “Logs/Traces Profile” object.
Once defined in the test design document, they can be associated to each test case to highlight which logs and traces need to be collected (when executing the test case), before opening a defect. In this way, testers will know which logs and traces to provide, when addressing an issue, even before executing a test case.
In this way, the tester can group all related logs and traces, and provide to the code developers. Having these Logs/Traces profile available, developer can investigate the issue/bug, understand them precisely and able to fix the problem, especially due to timing, synchronization, concurrency, and any other way.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an example of “Logs/Traces Profile”.
FIG. 2 is an example of “System Logs/Traces Profile”.
FIG. 3 is a block diagram of a typical system test cycle. It includes test case repository, test scenario, test case engine and template.
FIG. 4 is a representation of the concurrency test, where test case is performed between two test nodes at the same time to perform the concurrency test.
FIG. 5 is a representation of the test design document. It consists of a test case and test definition document (TDD).
FIG. 6 is a representation of the test profile which consists of a role and log/trace.
FIG. 7 represents the method of claim 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The Test Case Repository holds all the test cases in order to test the application. In general, each directory in the repository is devoted to a single issue. If a directory is empty, then no test scenarios have been created for the issue. In particular, test scenario (or often called test case) is a set of conditions under which a tester determines if a requirement or use case upon an application is partially or fully satisfied. It may take many test cases with several round of testing to determine that a requirement of the application is fully satisfied.
Test case is a documentation comprising pre-condition, input data, and post-condition with predicted results. It clearly describes the step-by-step process to test any piece of code.
Every test case depends on timing, synchronization, concurrency and others issues. Most IT managers agree that concurrency testing is the appropriate way to determine many performance bottlenecks, resource contention issues, and service interruptions. However, few ever do concurrency testing because the available test tools are not satisfactory.
There is no set concurrency testing in software testing life-cycle. You can never create a deterministic test to uncover a non-deterministic concurrency issue. The goal, instead, is to get close to the problem and to get lucky. Operating a concurrency test with as many of the above operational parameters might not guarantee that the test will surface concurrency issues, but it will work the odds in your favor to run across the right conditions to trigger a failure.
If synchronization is to take place automatically the system will determine when it shall take place. This will be at points in the testing process such as:
When a group of tests starts When a single test starts At the end of each test At the end of each group of tests
So, most of the defects cannot be understood simply by describing the steps performed by the tester during testing phase due to timing, synchronization, concurrency and others issues. There is also a possibility that the problem may not be reproduced on the next try either by the developer during code fix or by the tester during execution of the test cases.
An example of the present invention is to provide a tool that defines the Logs/Traces Profile objects (comprising of Role and the log and trace file locations), incorporates them within the test design document, and associates the Role(s) to individual test cases within the document.
There will be a set of predefined profiles comprising of different roles with log/trace detail, under which the computing device or system will be tested. Number and type of profiles will depend on the application to be tested.
System uses the templates associated with specific products, which are used in the test environment, to test the application. These templates have information about where the logs and traces files are generated and/or collected during execution of the test cases related to the product. These templates will need to be customized to specifically identify the machine were these logs/traces are located.
In FIG. 1 , TMR (Tivoli (Reg. Trademark) Management Region) represents a role and the profile includes the list of files that must be collected when this “Logs/Traces Profile” is associated to a test case. This means that before opening a defect for that test case, the specified files must be collected on the TMR server and provided to development team. Having these Logs/Traces profile, developer can investigate the issue/bug, understand them precisely, and be able to fix the problem. ( FIG. 1 )
FIG. 2 shows an example of “System Logs/Traces Profile”. It applies to the TMR, Admin server, and endpoint roles. They include the list of files that must be collected on each machine covering the related role when these “Logs/Traces Profile” is associated to a test case. This means that before opening a defect for that test case, the specified files must be collected on the TMR, Admin server and Endpoint and provided to development team. ( FIG. 2 )
Therefore, the test design should include a definition of all the relevant “Logs/Traces Profile” and “System Logs/Traces Profile”, and each test case should be associated to the related “Logs/Traces Profile” or “System Logs/Traces Profile” to keep the tester informed of the identity and location of the files needed to be provided to the development team before opening a defect related to the test case.
System has predefined templates related to specific products (e.g. Tivoli (Reg. Trademark)) that should be customized with the name of the machines where the files need to be collected. Test case machine associated with the roles can be accessed remotely by the developer team to collect the files, based on the specified “Logs/Traces Profile” or “System Logs/Traces Profile”. Test case machine provide the files all together at a location accessible to the development team.
A testing design document will be provided to each tester to test the system. The test design document ( FIG. 3 ) includes test case and test definitions. Test case, which is based on the template, associated to a corresponding application, defines the path to corresponding log and trace. Test definition document stores the definition of “Logs/Traces Profile” and “System Logs/Traces Profile”. ( FIG. 3 )
Each test case for specified role is tested by the tester. It indicates a failure or a success based on predefined post conditions of the test case. In case of test case failure, log and trace are generated during the execution of test case, on a test environment or a test device. ( FIG. 4 )
System locates and pulls those files when there is an issue during the test case execution from the test environment to a location accessible to the developers (e.g. bug tracking system or a shared space). In case of a failure, it clearly indicates which of (one or more) corresponding devices contributing to test case failure.
System automatically gathers corresponding log and trace, with the corresponding profile and role, and stores in a database repository. These details of log and traces, with corresponding profile and role, will be available to code developer to trace the exact cause of failure, understand and fix them. These details, with role and profile, including traces and logs, are very useful and necessary for a developer to avoid issues related to lack of synchronization, timing, concurrency, and reproducibility.
In one example, we have a method for associating logs and traces to test cases during a life-cycle of code development and testing, for a network or plurality of computing devices. The method comprises the following steps, as an example:
associating a first application to one or more of the network or plurality of computing devices; associating a first role to a first one of the network or plurality of computing devices; for the first one of said network or plurality of computing devices, configuring a path, a trace, and a log; ( FIG. 6 ) providing a profile; wherein the profile comprising the first role and the log; providing a test design document, wherein the test design document comprises a first test case and definitions, wherein the first test case describes how to test and what to test, ( FIG. 5 ) wherein the first test case comprises post-condition and pre-condition, ( FIG. 5 ) wherein the log and the trace are generated during the execution of the first test case, on a test environment or a test device, to track problems, issues, and bugs, and
wherein the first test case indicates a failure or a success.
If a specific test case indicates a failure, then the system indicates which role within which profile is associated with said specific test case, defines a template, associated to a corresponding application, to provide a path to corresponding log and trace, customizes the template to identify one or more of corresponding devices among the network or plurality of computing devices, where the corresponding log and trace are located, indicates which of the one or more of corresponding devices contributing to said failure, automatically gathers the corresponding log and trace, with the corresponding profile and role, in a database repository, and automatically provides the corresponding log and trace, with the corresponding profile and role, to a code developer, to track the exact cause of said failure, and to avoid issues related to the lack of synchronization, timing, concurrency, and reproducibility.
A system, apparatus, or device comprising one of the following items is an example of the invention: logs, traces, testing equipment, storage for logs and traces, server, computer, system software, microprocessor, processor, event handlers, testing system or module, client device, PDA, mobile device, cell phone, router, switches, network, communication media, cables, fiber optics, physical layer, buffer, nodes, packet switches, timer, synchronizer, computer monitor, or any display device, applying the method mentioned above, for purpose of logging, tracing, testing, and error/system management.
Any variations of the above teaching are also intended to be covered by this patent application.
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One of the examples is to define and use the concept of “Logs/Traces Profile” and “System Logs/Traces Profile” (including a role and the log and trace file locations), and incorporate them within the test design document. Each test design document can be associated to each test case to highlight which logs and traces need to be collected during its execution. In this way, the testers will know which logs and traces to provide to the code developers, when addressing an issue. In this way, developer can investigate the bug, understand them, and be able to fix the problem, especially due to timing, synchronization, and concurrency.
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This application is a continuation of Ser. No. 07/938,307, filed Aug. 28, 1992, now abandoned, which is a continuation of Ser. No. 07/526,314, filed May 18, 1990, now abandoned, which is a continuation-in-part of Ser. No. 07/436,141, filed Nov. 13, 1989, now abandoned, which is a continuation-in-part of Ser. No. 07/178,118, filed Apr. 6, 1988, now U.S. Pat. No. 4,882,421.
BACKGROUND OF THE INVENTION
The invention relates to pharmaceuticals, and more particularly relates to pharmaceuticals for use in treating cells which cause cancer tumors in humans.
The above-referenced patent application discloses a pharmaceutical which will be referred to herein by the intended trademark ONCONASE. It has now been determined that when this pharmaceutical is used in vitro in a combined therapy with other drugs, the results of the combined therapy are, in certain instances, much more bioactive than would be expected.
One such other drug is marketed under the TAMOXIFEN trademark and another such drug is marketed under the STELAZINE trademark.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood with reference to the following illustrative and non-limiting drawings, in which:
Table 1 shows experimental data illustrating how a combined therapy of ONCONASE and STELAZINE has a much greater bioactivity against A-549 human lung carcinoma cells than do either ONCONASE or STELAZINE separately.
Table 2 shows experimental data illustrating how a combined therapy of ONCONASE and TAMOXIFEN has a much greater bioactivity against ASPC-1 human pancreatic adenocarcinoma cells than do either ONCONASE or TAMOXIFEN separately.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In vitro data indicate that a combination of ONCONASE with a drug sold under the TAMOXIFEN trademark is much more bioactive against human pancreatic ASPC-1 adenocarcinoma than would be expected, given the separate activities of ONCONASE and TAMOXIFEN. In vitro data also indicate that a combination of ONCONASE with a drug sold under the STELAZINE trademark is much more bioactive against human lung A-549 carcinoma than would be expected, given the separate activities of ONCONASE and STELAZINE.
The preferred embodiment of the invention was tested using a cell culture assay. In such an assay, a cell line of known growth rate over a predetermined period is treated with the substance under test and the growth of the treated cells is compared with the growth which would ordinarily be expected from untreated cells.
ONCONASE, described in the above-referenced pending patent application and manufactured in accordance with the methodology described in U.S. Pat. No. 4,882,421 (which methodology is hereby incorporated herein by reference as if fully set forth herein) was dissolved in phosphate buffered saline (PBS) to obtain 1 mg/ml stock solution.
TAMOXIFEN is produced by Sigma Chemical Co., St. Louis Mo. and is a trademark for (Z-1-p-dimethylaminoethoxyphenyl-1, 2-diphenyl-1-butene), citrate salt. In the experiments described herein, TAMOXIFEN was dissolved in absolute ethanol and diluted with RPMI 1640 medium (as produced by Hazleton Research Products, Lenexa, Kans.) to obtain 1 mM stock solution (final concentration of ethanol 11%).
STELAZINE is produced by SK&F Co., subsidiary of SmithKline Beckman Co., Carolina P. R. and is a trademark for (10-[3-(4-methylpiperazin-1-yl)-propyl]-2-trifluoromethylphenothiazine). In the experiments described herein, STELAZINE was diluted with RPMI 1640 medium to obtain 1 mM stock solution.
The assay system utilized the ASPC-1 human pancreatic adenocarcinoma cell line and the A-549 human lung carcinoma cell line; both lines were obtained from the American Type Culture Collection (accession numbers were ATCC CRL 1682 for ASPC-1 and ATCC CCL 185 for A549-). Both cell lines were cultured in RPMI 1640 medium (Hazleton Research Products) and supplemented with 20% (ASPC-1) or 10% (A-549) heat-inactivated fetal bovine serum (Gibco Life Technologies, Grand Island N.Y.) and antibiotic-antimycotic solution composed of: 10,000 units per 1 ml penicillin, 10 mg per 1 ml streptomycin and 25 μg per 1 ml fungizone (complete growth medium). The cells were seeded into 96-well tissue culture plates manufactured by Falcon, of Oxnard, Calif. at a density of 2000 viable cells (50 μl per well) for the A-549 cell line and 4000 viable cells (50 μl) per well for the ASPC-1 cell line. The cell number was based on the previously determined growth curve characteristics for seven days of culture. The cells were allowed to settle for 24 hours and then 50 μl of appropriate ONCONASE and/or TAMOXIFEN or STELAZINE solutions were added per well. The following final concentrations were used:
a) ONCONASE, 20 ng to 10 μg/ml;
b) TAMOXIFEN, 10 μM for ASPC-1 cells; and
c) STELAZINE, 5 μM.
The plates were incubated for an additional six days at 37° C. and 5% carbon dioxide atmosphere. The total assay time was consequently seven days (one day in which the cells are allowed to settle, and six days of incubation). Percentages of viable cells were then determined using the MTT colorimetric assay using the Bio-Rad EIA microtiter plate reader.
The number of cells was determined by a direct count in an AO-Spencer "Brightline" hemocytometer manufactured by Reichert Scientific Instruments in Buffalo, N.Y. with a Neubauer ruling. All solutions used for this purpose were manufactured by Hazleton Research Products. Attached cells were washed three times with Hanks' Balanced Salt Solution and treated with 2 ml of a 0.25% Trypsin--0.02% EDTA solution in buffered saline for about thirty seconds. The solution was removed and the cells were left at 37° C. for 10 minutes, then suspended in 10 ml of the complete growth medium. The 0.25 ml of the cell suspension was diluted with 0.75 ml of the complete growth medium and then 1 ml of 0.5% Trypan Blue solution was added and viable cells were counted.
Tables 1 and 2 present the result of the above experiments. These tables are expressed in mean percent of growth inhibition, i.e. they indicate the effectiveness with which the tested therapies prevented the tested cancer cells from growing over the one week duration of the assay. Thus, a higher number indicates a higher bioactivity against the cell line used in the experiment.
These results demonstrate that, in the instances shown, the bioactivities of ONCONASE combined with STELAZINE in the case of A-549 human lung carcinoma and ONCONASE combined with TAMOXIFEN in the case of ASPC-1 human pancreatic adenocarcinoma are much greater than would be expected from the bioactivities of the individual drugs alone. This may be seen from the ED 50 figures which are along the right edge of the Tables. These figures represent computed isoeffective doses; the figure shown is the amount of material which would be required to halve the growth rate of the cells undergoing the assay. Thus, the lower the ED 50 figure, the smaller the dose required to achieve the same bioactivity.
Chemical Analysis and Composition of ONCONASE
ONCONASE has been well characterized chemically. While ONCONASE is a protein isolated from rana pipiens, it is believed that ONCONASE may be produced using genetic engineering techniques, as long as the end result has the following chemistry and structure:
ONCONASE is a pure protein (i.e. homogeneous, as established by standard tests which are used to assay the homogeneity of proteins). By electrophoresis, the molecular weight of ONCONASE is approximately 14,500 Daltons. Calculation of the molecular weight based upon the below listed amino acid sequence indicates that the molecular weight should be 11,819 Daltons. However, because metal ions may have bonded to the protein despite all efforts to remove them, and because different isotopes may be involved, the molecular weight of ONCONASE as determined by mass spectroscopy is 12,430 Daltons. In view of this discrepancy, the molecular weight of ONCONASE as determined by mass spectrometry will be considered to be approximately 12,000 Daltons. ONCONASE has an isoelectric point pI between 9.5 and 10.5, as determined by isoelectric focusing. ONCONASE has a blocked amino terminal group and is essentially free of carbohydrates (as determined by anthrone and orcinol methods).
______________________________________ONCONASE has the following amino acid composition:Amino Acid Analysis MOL %AMINO ACID RESIDUE (24 HOUR ACID HYDROLYSIS)______________________________________Aspartic acid/Asparagine 13.39Threonine 9.84 (Note 1)Serine 8.08 (Note 1)Glutamic acid/Glutamine 5.88Proline 3.98Glycine 2.98Alanine 2.92Cystine/2 7.77Valine 7.77Methionine 0.94Isoleucine 5.29 (Note 2)Leucine 4.95Tyrosine 2.85Phenylalanine 5.73Hisitidine 2.99Lysine 11.78Arginine 2.85Tryptophan Not Determined (Note 3)Approximate Total 99.99%______________________________________ Note 1: Threonine and serine are partially destroyed during hydrolysis an this value is corrected for such partial destruction. Note 2: This value is corrected for incomplete hydrolysis. Note 3: Tryptophan cannot be detected in acid hydrolysis of proteins because it is destroyed and is consequently shown as Not Determined. However, analysis of the ultraviolet spectrum revealed the presence of on tryptophan residue per molecule.
______________________________________Amino Acid Composition(as calculated from amino acid sequence) NUMBER OF RESIDUESAMINO ACID PER MOLECULE OF MATERIAL______________________________________Aspartic acid 6Asparagine 8Threonine 10Serine 8Glutamic acid 3Pyroglutamic acid 1Glutamine 2Proline 4Glycine 3Alanine 3Cystine/2 8Valine 8Methionine 1Isoleucine 6Leucine 5Tyrosine 3Phenylalanine 6Histidine 3Lysine 12Arginine 3Tryptophan 1Approximate Total 104______________________________________
ONCONASE has been sequenced. As is shown below, the total length of the sequence is 104 residues. The N-terminus of the protein is pyroglutamic acid (<Glu). This is a cyclized derivative of glutamic acid which is devoid of the free amino group necessary for direct sequencing and which therefore "blocks" the N-terminus of the protein.
When the shorter fragment described in U.S. Pat. No. 4,882,421 was cleaved with pyroglutamate aminopeptidase, pyroglutamic acid was removed from the shorter fragment, permitting sequencing to commence at the second residue. Such cleavage is a strong indication that the N-terminus is pyroglutamic acid since pyroglutamate aminopeptidase only cleaves pyroglutamic acid. The presence of pyroglutamic acid was further confirmed by mass spectrometry of the referenced shorter fragment. The molecular weight of this shorter fragment determined by mass spectrometry agreed well with the weight as calculated assuming that pyroglutamic acid was present and disagreed with the weight as calculated assuming that glutamic acid was present.
ONCONASE has the following amino acid sequence: ##STR1##
Although a preferred embodiment has been described above, the scope of the invention is limited only by the following claims:
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A pharmaceutical to be sold under the ONCONASE trademark, as described in pending commonly owned application application Ser. No. 07/436,141 filed Nov. 13, 1989 is combined with other drugs sold under the trademarks TAMOXIFEN and STELAZINE. The combination of ONCONASE with TAMOXIFEN has unexpected bioactivity in vitro against ASPC-1 human pancreatic adenocarcinoma cells and the combination of ONCONASE with STELAZINE has unexpected bioactivity in vitro against A-549 human lung carcinoma cells.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a signal transmission and reception device which performs communications by using impulse UWB (Ultra Wide Band) signals.
2. Description of the Related Art
In spread spectrum communications, in order to obtain a large variety of correlation characteristics, it is proposed to convert Pseudorandom Noise (PN) codes used in DSSS (Direct Sequence Spread Spectrum) to Return-to-Zero (RZ) codes, and multiply the RZ codes by data. For example, Japanese Laid-Open Patent Application No. 4-347943 (referred to as “reference 1” hereinafter) discloses a technique in this field. Since each PN code can have a positive or a negative value, by converting the PN codes to the RZ codes, output data becomes zero in a certain time period of the PN code, thus, each RZ code can have three types of values, that is, a positive, zero, or a negative value.
On the other hand, a UWB-IR (UWB-Impulse Radio) communication system is attracting attention since the UWB-IR system is capable of large capacity data transmission and is able to accommodate a large number of users. Since impulses shorter than 1 ns are used in the UWB-IR system, and the corresponding frequency band is at a few GHz, conventional radio communications are not interfered with; thus the frequency band can be shared.
For example, it is proposed that a signal transmission device supporting the UWB-IR communications performs spread modulation and RZ conversion of the PN codes on data carried by the carrier, and converts the resulting data to impulse radio signals. Further, a signal reception device for receiving the impulse radio signals has been developed. For example, Japanese Laid-Open Patent Application No. 2006-114980 (referred to as “reference 2” hereinafter) discloses a technique in this field.
In addition to the capability of large capacity data transmission, when the UWB-IR communication system is used in data transmission, it is possible for the transmitter to measure positions with high precision. Further, when a receiver supporting the UWB-IR communications is used together with the transmitter, it is possible to measure distances with high precision.
SUMMARY OF THE INVENTION
It is a general object of the present invention to make some novel improvements.
One specific object of the present invention is to provide a compact signal transmission and reception device having a one-chip impulse receiver and a one-chip impulse transmitter, having low power consumption and capable of position and distance measurements, and data communications.
According to a first aspect of the present invention, there is provided a signal transmission and reception device, comprising:
a transmission unit that converts transmission data spread by spread codes to a RZ signal, multiplies a code of an impulse series by the RZ signal to convert the RZ signal to an impulse radio signal, and transmits the impulse radio signal, said transmission unit being integrated into one chip; and
a reception unit that receives and demodulates the impulse radio signal, said reception unit being integrated into one chip.
As an embodiment, a special position of the signal transmission and reception device may be determined when the signal transmission and reception device receives the impulse radio signal transmitted by the signal transmission and reception device itself.
As an embodiment, the signal transmission and reception device further comprises:
a distance measurement unit that measures a distance between the signal transmission and reception device and an object based on a time difference between an impulse radio signal transmitted by the transmission unit toward the object and an impulse radio signal reflected by the object and received by the reception unit.
As an embodiment, the signal transmission and reception device further comprises:
a filtering unit that passes through the impulse radio signal transmitted by the transmission unit and the impulse radio signal received by the reception unit,
wherein
the filtering unit includes
a first pass band for passing through an impulse radio signal for use of Ultra Wide Band communications, a second pass band different from the first pass band and for passing through an impulse radio signal for measuring the distance to the object, and
the filtering unit is able to switch the first pass band and the second pass band.
As an embodiment, the signal transmission and reception device further comprises:
an adjustment terminal that connects an adjustment device for adjusting electric power of the impulse radio signal transmitted by the transmission unit.
As an embodiment, the signal transmission and reception device further comprises:
a detection terminal that connects a detection device for detecting a level of the impulse radio signal received by the reception unit.
As an embodiment, in the signal transmission and reception device, a common clock signal is supplied to the transmission unit and the reception unit.
As an embodiment, in the signal transmission and reception device each of the transmission unit and the reception unit is formed of a CMOS or a silicon-germanium semiconductor.
As an embodiment, the signal transmission and reception device further comprises:
a switching unit that connects one of the transmission unit and the reception unit to a transmission and reception antenna; and
a controller that controls the switching unit.
As an embodiment, the signal transmission and reception device further comprises:
a sensor terminal that connects an external sensor; and
a converter that converts detection signals from the external sensor into digital signals.
According to the present invention, it is possible to provide a compact signal transmission and reception device having a one-chip impulse reception unit and a one-chip impulse transmission unit, having low power consumption and capable of position and distance measurements, and data communications.
These and other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments given with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating a configuration of a signal transmission and reception device according to an embodiment of the present invention;
FIG. 2 is a flowchart illustrating switching a signal transmission procedure and a signal reception procedure in the signal transmission and reception device 1 of the present embodiment; and
FIG. 3 is a flowchart illustrating a procedure of distance measurement performed by the signal transmission and reception device 1 of the present embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Below, preferred embodiments of the present invention are explained with reference to the accompanying drawings.
FIG. 1 is a block diagram illustrating a configuration of a signal transmission and reception device according to an embodiment of the present invention.
As illustrated in FIG. 1 , a signal transmission and reception device 1 includes a transmitter 10 , a receiver 20 , a controller 30 , a switch 40 , an antenna 50 , and a power supplier 60 . Each of the transmitter 10 , the receiver 20 , the controller 30 , the switch 40 , and the power supplier 60 is integrated into one chip by using CMOS (Complementary Metal Oxide Semiconductor).
The transmitter 10 includes a transmission base band processing unit 11 , an impulse converter 12 , an amplifier 13 , and a transmission filter 14 .
The receiver 20 includes a reception filter 21 , a low-noise amplifier (LNA) 22 , a detector (DET) 23 , and a reception base band processing unit 24 .
Each of the transmission filter 14 and the reception filter 21 includes a first pass band for passing through impulse radio signals used for Ultra Wide Band communication, and a second pass band for passing through impulse radio signals for distance measurement (as described below), and each of the transmission filter 14 and the reception filter 21 is able to switch the first pass band and the second pass band. For example, the first pass band is set at 4.5 GHz for Ultra Wide Band communications, and the second pass band is set at 1 GHz.
A common clock signal is supplied to the transmission base band processing unit 11 and the reception base band processing unit 24 . For example, as shown in FIG. 1 , a clock signal input to the transmission base band processing unit 11 via a clock terminal 15 is also input to the reception base band processing unit 24 .
The amplifier 13 is connected to an adjustment terminal 16 , which connects the amplifier 13 to an adjustment device for adjusting, from the outside, the electric power of the impulse radio signals to be transmitted.
The detector (DET) 23 is connected to a detection terminal 25 , which outputs a signal indicating strength of received impulse radio signals. This signal is referred to as a “RSSI (Received Signal Strength Indicator) signal” below, where necessary.
For example, the controller 30 includes a CPU (Central Processing Unit). The controller 30 is connected to an interface (I/F) 31 , a pulse input terminal 32 , an analog signal input terminal 33 (AIN), an Analog-Digital-Converter (A/D) 34 , and a flash memory terminal 35 .
For example, the interface (I/F) 31 is a serial peripheral interface (SPI). For example, when a USB (Universal serial Bus) memory is connected to the interface 31 , various kinds of data to be transmitted can be input to the signal transmission and reception device 1 .
For example, the pulse input terminal 32 is for inputting pulse signals used for distance measurement (as described below).
The analog signal input terminal 33 (AIN) is connected to an acceleration meter (not illustrated). An analog signal input from the acceleration meter through the analog signal input terminal 33 is converted into a digital signal, and is input to the transmitter 10 via the controller 30 .
The flash memory terminal 35 , for example, similar to the interface (I/F) 31 , also supports the serial peripheral interface (SPI). While the interface 31 is used for inputting transmission data, the flash memory terminal 35 is primarily used for inputting identification signals to the controller 30 . For example, the identification signals include identifiers for individual identification.
The controller 30 performs calculations for measuring the distance to an object based on a time difference between a transmitted wave and a received wave (namely, the delay time of the received wave relative to the transmitted wave).
The switch 40 , which is used for switching transmitted and received signals, is connected to an output terminal 10 A of the transmitter 10 , and an input terminal 20 A of the receiver 20 . Additionally, the switch 40 is connected to the antenna 50 , which is used for transmitting or receiving signals.
A power terminal 61 is provided on the signal transmission and reception device 1 for supplying power from the outside to the power supplier 60 .
Below, operations of the signal transmission and reception device 1 are described.
First, explanations are made when the signal transmission and reception device 1 is used in a position measurement system for measuring the special position of the signal transmission and reception device 1 .
For example, the position measurement system includes a calculation device, which performs position measurement processing for measuring the special position of the signal transmission and reception device 1 , and plural signal transmission and reception devices connected to the calculation device. Below, the plural signal transmission and reception devices are referred to as “nodes”. These nodes are arranged at positions allowing UWB communications with the signal transmission and reception device 1 . The signal transmission and reception device 1 is used as a tag, and is arranged in a space which is to be measured. Each of these nodes can be the same as the signal transmission and reception device 1 , and this allows radio communications between the nodes.
In the position measurement system, when impulse radio signals transmitted from the signal transmission and reception device 1 , which is used as a tag, are received by one of the nodes, the calculation device performs position measurement processing based on the position of the node which receives the impulse radio signals and the time of receiving the impulse radio signals by the node, and by this position measurement processing, the special position of the signal transmission and reception device 1 can be determined with high precision.
Specifically, when the controller 30 directs to turn the transmitter 10 ON, the transmission base band processing unit 11 encodes and compresses digital data used for position measurement by known appropriate methods, and outputs the encoded and compressed data to the impulse converter 12 . The impulse converter 12 modulates the compressed data from the transmission base band processing unit 11 , for example, by phase modulation or others, and then, the modulated data are further modulated by spread modulation by using the PN (Pseudorandom Noise) codes. Further, the impulse converter 12 converts the data modulated by spread modulation to RZ signals, and the RZ signals are converted into impulse radio signals. At this stage, since the transmitter 10 and the antenna 50 are connected through the switch 40 controlled by the controller 30 , the output signals from the impulse converter 12 are amplified by the amplifier 13 to a certain level, and are transmitted from the antenna 50 through the transmission filter 14 .
When the impulse radio signals transmitted from the antenna 50 of the signal transmission and reception device 1 are received by one of the nodes of the position measurement system, and the above position measurement processing is executed, the special position of the signal transmission and reception device 1 can be determined with high precision.
When the controller 30 directs to turn the receiver 20 ON, the switch 40 is switched to the receiver 20 side, and the signal transmission and reception device 1 is ready for receiving data from the node.
When the receiver 20 receives the impulse radio signals from the node, the signal transmission and reception device 1 determines whether the received impulse radio signals are those sent to itself.
FIG. 2 is a flowchart illustrating switching of a signal transmission procedure and a signal reception procedure in the signal transmission and reception device 1 of the present embodiment.
Note that the procedure shown in FIG. 2 can be executed by the transmitter 10 , the receiver 20 , and the controller 30 .
As shown in FIG. 2 , in step S 20 , the controller 30 switches the switch 40 in each specified time period to determine whether the impulse radio signals are received.
In this way, impulse radio signals involved in the determination by the controller 30 are signals transmitted from a node of the position measurement system. When the receiver 20 receives the impulse radio signals, the receiver 20 demodulates the received impulse radio signals, and transmits the demodulated data to the controller 30 .
When it is determined that the impulse radio signals are not received, the procedure proceeds to step S 21 .
In step S 21 , the switch 40 is switched to the transmitter 10 side.
In step S 22 , the transmitter 10 encodes and compresses the transmission data by appropriate coding methods. In this step, the base band is modulated by the transmission base band processing unit 11 .
In step S 23 , the transmitter 10 performs spread modulation and RZ conversion by using the PN (Pseudorandom Noise) codes, and the RZ signals are converted into impulse radio signals. In this way, the impulse radio signals are produced.
In step S 24 , the impulse radio signals are transmitted from the antenna 50 .
In step S 25 , when it is determined by the controller 30 in step S 20 that the impulse radio signals are received, base band demodulation is performed on the received impulse radio signals.
In step S 26 , the controller 30 confirms the identifier included in the demodulated signals.
In step S 27 , when the controller 30 determines that the identifier included in the demodulated signals is the same as the identifier of the signal transmission and reception device 1 , the controller 30 reads in the received data, and performs processing according to the received data.
Concerning the impulse radio signals transmitted from the position measurement system and received by the receiver 20 , for example, when plural signal transmission and reception devices 1 are present in a certain space, the impulse radio signals may be signals including data for ranking the signal transmission and reception devices 1 . Due to this, since plural signal transmission and reception devices 1 can be ranked in the position measurement system to perform data communications sequentially, data for performing calling out and standby can be transmitted to the signal transmission and reception devices 1 .
Signals indicating data requested by the signal transmission and reception device 1 can be transmitted from the position measurement system to the signal transmission and reception device 1 . Due to this, when the signal transmission and reception device 1 is used in the position measurement system, it is possible to construct a network system.
If an acceleration meter is connected to the analog signal input terminal 33 of the signal transmission and reception device 1 , and acceleration data detected by the acceleration meter are sent to the position measurement system, the position measurement system is able to determine the position of the signal transmission and reception device 1 . Furthermore, the position measurement system can receive acceleration data detected by the acceleration meter connected to the signal transmission and reception device 1 .
FIG. 3 is a flowchart illustrating a procedure of distance measurement performed by the signal transmission and reception device 1 of the present embodiment.
As described above, the signal transmission and reception device 1 is able to transmit or receive the impulse radio signals. If the signal transmission and reception device 1 is configured to receive impulse radio signals transmitted by itself toward a specified target, the distance from the signal transmission and reception device 1 to the target can be measured. For example, the controller 30 performs calculations and processing required for the distance measurement.
As shown in FIG. 3 , in step S 30 , the controller 30 switches the switch 40 to the transmitter side.
In step S 31 , the transmitter 10 generates impulse radio signals based on pulse signals from the controller 30 . For example, the pulse signals are input from a pulse generator (not illustrated) connected to the pulse input terminal 32 and are used for distance measurement. At the stage, the pass band of the transmission filter 14 may be switched to the second pass band to transmit impulse radio signals at 1 GHz.
In step S 32 , the controller 30 switches the switch 40 to the side of the receiver 20 .
In step S 33 , the receiver 20 demodulates the received impulse radio signals.
In step S 34 , it is determined whether the transmitted impulse radio signals and the received impulse radio signals are sufficiently strongly correlated to each other. For example, this determination can be executed by sliding correlation.
In step S 35 , when it is determined that sufficiently strong correlation exists, the controller 30 calculates the time delay between the transmitted impulse radio signals and the received impulse radio signals.
In step S 36 , the controller 30 calculates the distance to the target based on obtained time delay.
When it is determined that sufficiently strong correlation does not exist, the controller 30 returns to step S 30 .
In this way, the distance to the target can be obtained by the signal transmission and reception device 1 of the present embodiment.
If the signal transmission and reception device 1 is used outside, it can be used in a radar device to realize various applications. That is, the place for using the signal transmission and reception device 1 is not limited to the above mentioned desired space where the position measurement system is installed.
According to the present embodiment, it is possible to provide a compact signal transmission and reception device formed from a one-chip impulse receiver 20 and a one-chip impulse transmitter 10 , having low power consumption and capable of position and distance measurements, and data communications.
While the invention is described above with reference to specific embodiments chosen for purpose of illustration, it should be apparent that the invention is not limited to these embodiments, but numerous modifications could be made thereto by those skilled in the art without departing from the basic concept and scope of the invention.
For example, it is described above that each of the transmitter 10 , the receiver 20 , the controller 30 , the switch 40 , and the power supplier 60 is integrated into one chip by using CMOS (Complementary Metal Oxide Semiconductor), but the present invention is not limited to this. Instead of CMOS, the transmitter 10 , the receiver 20 , the controller 30 , the switch 40 , and the power supplier 60 can be integrated into one chip by using silicon-germanium semiconductor.
It is described above that the transmitter 10 and the receiver 20 have built-in transmission filter 14 and reception filter 21 , respectively, but the present invention is not limited to this. The transmission filter 14 and reception filter 21 can be provided outside the signal transmission and reception device 1 .
It is described above that the switch 40 switches the connection between the transmitter 10 and the receiver 20 with the antenna 50 , but the present invention is not limited to this. For example, the transmitter 10 and the receiver 20 may have their own antennae, respectively. In this case, the switch 40 can be omitted.
It is described above that the first pass band of the transmission filter 14 and reception filter 21 is set at 4.5 GHz, but the present invention is not limited to this. The first pass band can be set to be any value in a range from 3.1 to 10.6 GHz as long as the first pass band is a band allowing Ultra Wide Band communications.
In addition, when the signal transmission and reception device 1 does not measure the distance but only performs Ultra Wide Band communications, the transmission filter 14 and reception filter 21 may be omitted.
It is described above that the switch 40 is installed in the signal transmission and reception device 1 , but the present invention is not limited to this. The switch 40 may be provided outside the signal transmission and reception device 1 .
It is described above that an acceleration meter is connected to the analog signal input terminal 33 , but the present invention is not limited to this. Various sensors can be connected to the analog signal input terminal 33 , for example, when a sensor for detecting vital signs like blood pressure and pulsation, the vital data of the owner of the signal transmission and reception device 1 can be transmitted.
This patent application is based on Japanese Priority Patent Application No. 2007-051827 filed on Mar. 1, 2007, the entire contents of which are hereby incorporated by reference.
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A signal transmission and reception device is disclosed that can be made compact and has wide-band band-pass characteristics. The signal transmission and reception device includes a first filtering unit that is composed of a distributed constant circuit and is capable of eliminating a first frequency component or a second frequency component. The second frequency is higher than the first frequency, and a second filtering unit that attenuates components of frequencies lower than the first frequency or components of frequencies higher than the second frequency.
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This application is a continuation-in-part application of pending United States patent application filed on Oct. 3, 2008 and having application Ser. No. 12/245,479, which itself is a non-provisional application that claims priority on and the benefit of provisional application 60/998,009 filed Oct. 5, 2007, the entire contents of each hereby being incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a trigger assembly that can serve as a replacement trigger assembly for a Remington 700 rifle trigger assembly and for other rifles.
2. Description of the Related Art
The Remington 700 rifle is a well regarded firearm. The trigger assembly does generally work well for its intended purposes. Yet, there are some aspects of the trigger assembly that can be improved upon.
The Remington 700 rifle trigger assembly has a trigger that is pivotally housed within a housing. The trigger has a finger element and a head. The head has a top and a bottom, with the finger element being integral with the bottom of the head. A pivot hole is formed through the head near the bottom of the head. In this arrangement, pulling the finger element in a first angular direction causes the top of the head to move in the opposite angular direction about the pivot. A sear connect is at the top of the head. When the head rotates a given amount, the sear contact disengages the sear.
One drawback with this arrangement is that the pivot is approximately ½ way between the top of the head and the bottom of the finger element. In this regard, the force applied in the first direction by the user creates a torque on the trigger about the pivot. The created lever arm is less than optimal, as it is approximately equal to ½ of the trigger length. Having a short lever arm can lead to a decrease in the accuracy of the trigger assembly. Reasons for this include the geometry of pulling a short lever, which includes an undesirable ratio in the amount of vertical swing relative horizontal movement.
A further drawback is that the safety engages only the sear. While a safety engaging a single component can be adequate, it would be more desirable to have a safety engage multiple components in the trigger assembly to provide additional security in guarding against unintentional discharges.
There is a need for a trigger assembly that is adjustable between light and heavy.
There is a need for a trigger assembly that has low internal friction.
There is a need for a trigger assembly that is easily adapted for use as a single stage and a double stage trigger assembly.
There is a need for a trigger assembly that utilizes an increased lever arm for increased precision while maintaining a compact overall size.
There is a need for a trigger assembly with additional safety features.
There is a need for a trigger assembly that can act as a set trigger.
Thus there exists a need for a trigger assembly that solves these and other problems.
SUMMARY OF THE INVENTION
The present invention relates to a trigger assembly that can serve as a replacement trigger assembly for a Remington 700 rifle and other rifles. The trigger assembly can have a frame with a first side and a second side. Two spacer blocks can maintain spacing between the sides. A sear can be secured within the frame, and in particular pivotally secured at the front of the sear. A trigger can be provided. The trigger can be pivotally connected to the frame at or near the top of the trigger. A sear transfer bar can be further provided. The sear transfer bar is also pivotally connected to the frame. The pivot in the trigger may be higher within the frame as compared to the pivot of the sear transfer bar. One or more antifriction devices can be between the trigger and the sear transfer bar. The top of the sear transfer bar has a sear contact. Pulling the trigger in a first direction causes the trigger to rotate in a first direction. The trigger can cause the sear transfer bar to rotate after the trigger has rotated a defined amount, wherein pulling the trigger further causes the sear transfer bar to rotate. The sear will drop when the sear contact ceases engagement with the sear, causing the firearm to fire.
According to one advantage of the present invention, the trigger assembly is adjustable between light and heavy. This can be accomplished in several ways. In one embodiment, springs are provided for tensioning the trigger. In another embodiment, magnets are provided for tensioning the trigger. A light trigger can have a trigger pull of approximately 1 pound. A heavy trigger can have a trigger pull in the range of approximately 3 to 5 pounds. The trigger pull of the present invention is adjustable.
According to another advantage of the present invention, the trigger assembly has low internal friction. This is accomplished by selectably placing one or more antifriction devices between the trigger and the sear transfer bar. In one preferred embodiment, the antifriction devices can comprise ball bearings.
According to a further advantage of the present invention, the trigger assembly is easily adapted for use as a single stage and a double stage trigger assembly. This is accomplished in a preferred embodiment by selectably placing one or two antifriction devices between the trigger and the sear contact bar. The geometry of the engagement points between the trigger and the sear transfer bar determine the location and characteristics of the two stages.
According to a still further advantage yet of the present invention, the trigger assembly is utilizes an increased lever arm for increased precision while maintaining a compact overall size. This is accomplished by locating the trigger pivot at or near the top of the trigger such that the effective length of the trigger lever arm is maximized. Increasing the lever arm length can increase the trigger torque and reduce the force required to discharge the firearm. An increased lever arm length decreases the proportional or rational vertical component of the trigger swing.
According to a still further advantage yet of the present invention, the trigger assembly has a sear transfer bar with a radiused sear contact. The radiused sear contact provides a constant distance between the perimeter of the sear contact and the sear as the sear transfer bar rotates about its pivot. The sear, accordingly, will not travel until the sear contact clears and allows the sear to drop.
According to a still further advantage yet of the present invention, the trigger assembly is provided with a safety that acts as a double safety. This is accomplished by having a safety with one lug preventing the sear from dropping and a second lug preventing the sear transfer bar from pivoting out of the way of the sear.
According to a still further advantage yet of one embodiment of the present invention, the trigger can be configured to act as a set trigger. Friction between the sear transfer bar and the sear will hold the sear transfer bar in the set position between the first stage and the second stage. The trigger assembly can be un-cocked by toggling the safety to the safe position.
Other advantages, benefits, and features of the present invention will become apparent to those skilled in the art upon reading the detailed description of the invention and studying the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a first preferred embodiment of the present invention shown in a ready position.
FIG. 2 is a side view of the embodiment shown in FIG. 1 shown in the stage 1 position.
FIG. 3 is a side view of the embodiment shown in FIG. 1 shown in the stage 2 position.
FIG. 4 is a side view of the embodiment shown in FIG. 1 shown in the fired or safety off position.
FIG. 5 is a side view of the embodiment shown in FIG. 1 shown in the safety on position.
FIG. 6 is an isolated rear view of the trigger.
FIG. 7 is a side view of an alternative embodiment of the present invention.
FIG. 8 is a side view of an alternative embodiment of the present invention in a safety on position.
FIG. 9 is similar to FIG. 8 , but is illustrated in a safety off position.
FIG. 10 is an exploded side view of a preferred embodiment of a safety of the present invention.
FIG. 11 is an end view showing a preferred key of a control arm.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the invention will be described in connection with several preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
The present invention can be used with a Remington 700 rifle, and with similar style rifles. In a basic configuration, the firearm has a barrel with a longitudinal axis. The firearm has a cocking piece 1 with a cocking piece contact 2 . The cocking piece 1 fires when the cocking piece contact 2 clears the sear (described below).
Turning now to FIGS. 1-5 , a first preferred embodiment of a trigger assembly 10 is provided. The trigger assembly 10 can be a direct replacement for a standard assembly. The trigger assembly 10 has a frame 20 , a front spacer block 40 , a rear spacer block 50 , a sear 60 , a trigger 80 , a sear transfer bar 100 and a safety 120 . Each of these components is described in detail below.
The frame 20 has a first side and an opposed second side. Plates can be used on the sides to contain the other components of the housing. In the illustrated embodiment, one plate is removed to more clearly illustrate the components of the trigger assembly 10 . The frame 20 comprises a top 25 and a bottom 26 , a front 27 and a rear 28 . A first hole 29 is through the frame 20 . Hole 29 is preferably near the top 25 and front 27 of the frame 20 . A second hole 30 is also provided. The second hole 30 is preferably near the top 25 and rear 28 of the frame 20 . In one embodiment, the mount hole is round. In an alternative embodiment, the mount hole can comprise a single hole defined by two offset circles forming a double crescent hole. This allows the present assembly to be used with multiple firearms and in particular with firearms having the similar but different frame requirements. Mounting pins (not shown) can be received within holes 29 and 30 to hold and secure the frame 20 in place within the firearm.
The front spacer block 40 is located at the front 25 of the frame between the two sides. The block 40 has a top 41 with a pocket 42 formed therein. The pocket receives the end of a spring 131 . One preferred spring is a simple coil spring. It is appreciated that the spring is but one example of a force member that may be utilized within the present invention. The block 40 further has a bottom 43 , a front 44 and a rear 45 . A hole 46 can be formed through the block 40 and be open to the front 44 and rear 45 . The hole 46 is preferably a threaded hole and can receive a set screw 47 . The screw 47 can extend from the rear of the spacer block 40 to adjust trigger creep. It is appreciated that an additional hole (not shown) may also provided for receiving an embedded switch, such as a proximity switch for use with an integrated laser rangefinder (LRF) sight system.
Spacer block 50 is at the rear 28 of the frame. The block 50 has a top 51 with a pocket 52 formed therein. The pocket can receive one end of a spring 133 . One preferred spring is a simple coil spring. The block 50 further has a bottom 53 .
The first spacer block 40 and the second spacer block 50 maintain proper spacing of the side plates of the trigger assembly.
The sear 60 may be similar to a standard sear used in the Remington 700 rifles. The sear 60 is located at the top 25 of the frame 20 . The sear 60 has a front 61 and a rear 62 , a top 63 and a bottom 64 . An area 65 along the bottom 64 of the sear is relieved to make clearance during the fired or safety off position described below. A hole or pocket 66 is formed in the bottom 64 of the sear 60 . The second end of spring 131 can be received within hole 66 . The spring 131 provides a force against the sear 60 so that the top rear portion of the sear rests against a pin that supports the housing. The sear has a sear contact 67 . The sear contact 67 is at the bottom of the sear 60 between the front and the rear of the sear. A safety ear 68 is also provided. The ear 68 is at the bottom and rear of the sear. A pivot 69 is provided. The pivot hole is concentric with mounting hole 29 through the frame, wherein the mounting pin passes through both holes. The sear 60 can be in a first position and a second position. In the first position, the sear 60 can be engaged by the cocking piece. In this regard, the cocking piece contact 2 of the cocking piece 1 can engage a cocking piece contact 70 of the sear 60 . The cocking piece contact 2 of the cocking piece 1 can move past the sear 60 when the sear drops to its second position (shown in FIG. 4 ). A clearance step 71 can be provided to prevent interference between the sear 70 and cocking piece when the firearm is fired.
A trigger 80 , as seen in FIGS. 1-6 , is further provided. The trigger 80 has a finger element 81 and an arm 90 . The finger element 81 and arm 90 are preferably integrally formed as a single component. The finger element 81 has a top 82 and a bottom 83 . The finger element 81 further has a front 84 and a rear 85 . During use, the user applies a rearward force to the finger element by pulling against the front 84 surface. The finger element 81 further has a first side 86 and a second side 87 . A lip 88 projects forward at the top 82 of the finger element 81 . The lip 88 acts to prevent dust, dirt and other debris from entering the internal chamber of the trigger assembly 10 by coming into close engagement with the spacer block 40 in the ready position.
The trigger 80 further has an arm 90 . Arm 90 has a top 91 , a bottom 92 , a front 93 and a rear 94 . A pivot hole 95 is through the trigger between the sides. The pivot hole 95 is located near or adjacent to the top 91 of the arm 90 of the trigger 80 . The lever arm of the trigger 80 is effectively maximized. In this regard, the radius of rotation is approximately equal to the length of the trigger, resulting in minimum vertical variation of the trigger as it horizontally moves to the fired position.
A first channel 96 and a second channel 98 are provided between the sides of the arm, and are open to the rear 94 of the arm 90 . In this regard, the channels 96 and 98 generally resemble the shape of a C. A ball 97 is received within channel 96 , and a ball 99 is received within channel 98 . The balls project a selected distance rearward from the back 94 of the arm 90 of the trigger 80 . It is appreciated that having two balls results in a two-stage trigger. It is within the scope of the present invention to eliminate one ball, which would result in a single stage trigger. It is further appreciated that balls are but one example of a balled or rounded surface that could reduce friction between the components.
A pocket 100 is formed at the bottom 92 of the arm and is open to the rear 94 . The pocket can receive an end of a spring 132 .
A sear transfer bar 110 , or simply transfer bar, is further provided. The sear transfer bar 110 has a top 111 , a bottom 112 , a front 113 and a rear 114 . A pivot hole 115 is through the bar 110 at a point approximately half way between the top 111 and bottom 112 . It is understood that the location of the pivot of the transfer bar 110 may be moved without departing from the broad aspects of the present invention. A pocket 116 is formed in the transfer bar at the bottom 112 and is open to the front 113 . The second end of spring 132 is received within pocket 116 . A sear engager 117 is also provided. The sear engager 117 preferably comprises a radiused edge that contacts the sear contact 67 of the sear 60 . The sear engager 117 maintains constant location of the sear regardless of the rotational orientation of the bar 110 . A safety ear 118 is provided of the bar 110 . The safety ear 118 is preferably on the rear 114 of the bar between the top 111 and the bottom 112 .
Spring 132 applies a force to the bottom of the transfer bar 110 and bias the back of the transfer bar to against the safety or the second mounting plate. The spring force is overcome by the force of the trigger contacting the transfer bar when the trigger reaches a determined geometric location. Spring 132 remains in compression after the firearm fires and provides a force to force the bottom 112 of the bar 110 away from the released trigger 80 so that the sear contact 67 of the sear 60 and the sear engager 117 of the transfer bar can reengage.
During the step of pulling the trigger, the trigger can move from the first stage through the second to be in the set position. It is seen that the two balls 97 and 99 of the trigger 80 engage the transfer bar 110 in FIG. 2 , which shows the end of the first stage. Further pulling of the trigger 80 ( FIG. 3 ) results in only the second ball 99 contacting the transfer bar. At this point, further rotation of the trigger 80 about the pivot 95 will result in the ball 99 applying a greater force to the transfer bar 110 than the spring 132 applies. Since the ball 99 contacts the transfer bar 110 above pivot 115 , and the spring 132 acts below the pivot, further movement of the trigger will cause the transfer bar 110 to rotate about pivot 115 . It is understood that the trigger and the transfer bar will rotate in opposite directions because the trigger contacts the transfer bar above the center of rotation. It is further understood that the contact between the trigger and contact bar may occur below the transfer bar pivot, which would result in the trigger and transfer bar rotation in offset tandem without departing from the broad aspects of the present invention. The sear engager 115 of the transfer bar 110 will cease engagement with the sear contact 67 of the sear 60 when the transfer bar rotates, causing the sear second end 62 to drop and the firearm to fire.
It is appreciated that other low friction interfaces can be used between the trigger 80 and sear transfer bar 110 without departing from the broad aspects of the present invention. For example, the balls could be located in the transfer bar 110 instead of the trigger 80 without departing from the broad aspects of the present invention.
A safety 120 is still further provided yet. The safety 120 is preferably a double safety, and accordingly engages at least two internal components of the trigger assembly. The safety has a pivot 121 . A control arm 122 is provided for toggling the safety 120 between a safe position and a ready position. The control arm 122 can be justified for a left-handed shooter and for a right-handed shooter. A first lug 123 is provided for engaging the safety ear 118 of the transfer bar 110 . A second lug 124 is also provided for engaging safety ear 68 of the sear 60 . With the safety 120 in the safe position, lug 123 prevents the transfer bar from rotating (hence maintaining engagement between the sear engager 117 of the transfer bar 110 and the sear contact 67 of the sear), and lug 124 directly prevents the sear 60 from dropping. When the firearm is in the set position, the trigger assembly can be uncocked by placing the safety to the safe position. In this regard, lug 123 presses against ear 118 of the bar 110 to rotate bar 110 about pivot 105 away from the set position. Two detents 125 and 126 are provided. A safety ball 140 , or simply a ball, is further provided. The ball 140 rests on a spring 133 that is within pocket 52 in the spacer block 50 . The ball engages detent 125 when the trigger assembly is not in the safety on position, and engages detent 126 when the trigger assembly is in the safety on position. The control arm 122 is used to effect the toggling between the detents 125 and 126 , wherein spring 133 is temporarily compressed to allow the ball to move between the detents.
Turning now to FIG. 7 , a second preferred embodiment of a trigger assembly 210 is provided. The trigger assembly 210 can be a direct replacement for a standard assembly. The trigger assembly 210 has a frame 220 , a front spacer block 240 , a rear spacer block 250 , a sear 260 , a trigger 280 , a sear transfer bar 300 and a safety 320 . Each of these components is described in detail below.
The frame 220 has a first side and an opposed second side. Plates can be used on the sides to contain the other components of the housing. In the illustrated embodiment, one plate is removed to more clearly illustrate the components of the trigger assembly 210 . The frame 220 comprises a top and a bottom, a front and a rear. A first hole is through the frame 220 . Hole is preferably near the top and front of the frame 220 . A second hole is also provided. The second hole is preferably near the top and rear of the frame 220 . In one embodiment, the mount hole is round. In an alternative embodiment, the mount hole can comprise a single hole defined by two offset circles forming a double crescent hole. This allows the present assembly to be used with multiple firearms and in particular with firearms having the similar but different frame requirements. Mounting pins (not shown) can be received within holes and to hold and secure the frame 220 in place within the firearm.
The front spacer block 240 is located at the front of the frame between the two sides. The block 240 has a top 241 with a pocket 242 formed therein. The block 240 further has a bottom, a front and a rear. A hole can be formed through the block 240 and be open to the front and rear. The hole is preferably a threaded hole and can receive a set screw. The screw can extend from the rear of the spacer block 240 to adjust trigger creep. It is appreciated that an additional hole (not shown) may also provided for receiving an embedded switch, such as a proximity switch for use with an integrated laser rangefinder (LRF) sight system.
Spacer block 250 is at the rear of the frame. The block 250 has a top 251 with a pocket 252 formed therein. The block 250 further has a bottom.
The first spacer block 240 and the second spacer block 250 maintain proper spacing of the side plates of the trigger assembly 210 .
The sear 260 may be similar to a standard sear used in the Remington 700 rifles. The sear 260 is located at the top of the frame 220 . The sear 260 has a front 261 and a rear 262 , a top 263 and a bottom 264 . An area along the bottom 264 of the sear is relieved to make clearance during the fired position. A hole or pocket 266 is formed in the bottom 264 of the sear 260 . The sear has a sear contact. The sear contact is at the bottom of the sear 260 between the front and the rear of the sear. A safety ear is also provided. The ear is at the bottom and rear of the sear. A pivot 269 is provided. The pivot hole is concentric with mounting hole through the frame, wherein the mounting pin passes through both holes. The sear 260 can be in a first position and a second position. In the first position, the sear 260 can be engaged by the cocking piece. In this regard, the cocking piece contact of the cocking piece can engage a cocking piece contact of the sear 260 . The cocking piece contact of the cocking piece can move past the sear 260 when the sear drops to its second position. A clearance step can be provided to prevent interference between the sear 270 and cocking piece when the firearm is fired.
A trigger 280 is further provided. The trigger 280 has a finger element 281 and an arm 290 . The finger element 281 and arm 290 are preferably integrally formed as a single component. The finger element 281 has a top and a bottom. The finger element 281 further has a front and a rear. During use, the user applies a rearward force to the finger element by pulling against the front surface. The finger element 281 further has a first side and a second side. A lip projects forward at the top of the finger element 281 . The lip acts to prevent dust, dirt and other debris from entering the internal chamber of the trigger assembly 210 by coming into close engagement with the spacer block 240 in the ready position.
The trigger 280 further has an arm 290 . Arm 90 has a top, a bottom, a front 293 and a rear 294 . A pivot hole 295 is through the trigger between the sides. The pivot hole 295 is located near the top of the arm 290 of the trigger 280 . The lever arm of the trigger 280 is effectively maximized. In this regard, the radius of rotation is approximately equal to the length of the trigger, resulting in minimum vertical variation of the trigger as it horizontally moves to the fired position.
A first channel and a second channel are provided between the sides of the arm, and are open to the rear of the arm 290 . In this regard, the channels generally resemble the shape of a C. A ball is received within channel, and a ball is received within channel. The balls project a selected distance rearward from the back of the arm 290 of the trigger 280 . It is appreciated that having two balls results in a two-stage trigger. It is within the scope of the present invention to eliminate one ball, which would result in a single stage trigger. A pocket 300 is formed at the bottom of the arm and is open to the rear.
A sear transfer bar 310 is further provided. The sear transfer bar 310 has a top, a bottom, a front 313 and a rear 314 . A pivot hole 315 is through the bar 310 at a point approximately half way between the top and bottom. A pocket 316 is formed in the transfer bar at the bottom and is open to the front. A sear engager is also provided. The sear engager preferably comprises a radiused edge that contacts the sear contact of the sear 260 . The sear engager maintains constant location of the sear regardless of the rotational orientation of the bar 310 . A safety ear is provided of the bar 310 . The safety ear is preferably on the rear of the bar between the top and the bottom.
During the step of pulling the trigger, the trigger can move from the first stage through the second to be in the set position. The two balls of the trigger 280 may engage the transfer bar 310 , which occurs at the end of the first stage. Further pulling of the trigger 280 results in only the second ball contacting the transfer bar. At this point, further rotation of the trigger 280 about the pivot 295 will result in the ball applying a greater force to the transfer bar 310 than the forcing component (described below) applies. Since the ball contacts the transfer bar 310 above pivot 315 , and the forcing component acts below the pivot, further movement of the trigger will cause the transfer bar 310 to rotate about pivot 315 . The sear engager of the transfer bar 310 will cease engagement with the sear contact of the sear 260 when the transfer bar rotates, causing the sear second end to drop and the firearm to fire.
It is appreciated that other low friction interfaces can be used between the trigger 280 and sear transfer bar 310 without departing from the broad aspects of the present invention. For example, the balls could be located in the transfer bar 310 instead of the trigger 280 without departing from the broad aspects of the present invention.
A safety 320 is still further provided yet. The safety 320 is preferably a double safety, having a pivot 321 . A control arm 322 is provided for toggling the safety 320 between a safe position and a ready position. The control arm 322 can be justified for a left-handed shooter and for a right-handed shooter. A first lug is provided for engaging the safety ear of the transfer bar 310 . A second lug is also provided for engaging safety ear of the sear 260 . With the safety 320 in the safe position, lug prevents the transfer bar from rotating (hence maintaining engagement between the sear engager of the transfer bar and the sear contact of the sear), and the second lug directly prevents the sear 260 from dropping. When the firearm is in the set position, the trigger assembly can be uncocked by placing the safety to the safe position. In this regard, the first lug presses against ear of the bar 310 to rotate bar 310 about pivot away from the set position. Two detents and are provided. A ball is further provided. The ball engages detent when the trigger assembly is not in the safety on position, and engages detent when the trigger assembly is in the safety on position. The control arm 322 is used to effect the toggling between the detents, wherein the force component is temporarily compressed to allow the ball to move between the detents.
In this preferred embodiment, the force components may be comprised of pairs of magnets that are oriented in repulsion. In this regard, a series of magnets are preferably provided for maintaining the arrangement of the components and returning the trigger to the ready position. The magnets can be made of NeFeB, or any other suitable magnetic material.
One magnet 330 is received within the pocket 266 of the sear 260 , and a second magnet 331 is received within the pocket of the first spacer block 240 . Magnets 330 and 331 are oriented in repulsion so that there exists a repulsive force between the sear and the first spacer block.
A magnet 332 is received within the pocket 300 of the trigger 280 , and a second magnet 333 is received within the pocket 316 of the transfer bar 310 . Magnets 332 and 333 are oriented in repulsion so that there exists a repulsive force between the trigger and the bottom of the transfer bar.
Two magnets 335 and 336 are received within the pocket 52 of spacer block. The magnets are in repulsion, wherein a ball is biased upwards to engage one of the detents of the safety to maintain the safety in the desired position.
It is appreciated that because of the orientation (linear) of the polarity (opposites attract and equals repulse) of the magnets, the magnets will perform similar in function to springs. Accordingly, the trigger pull weight can be adjusted by adjusting the magnets.
It is appreciated that the location and strength of the magnets may be selected in order to adjust the firing characteristics of the firearm.
Turning now to FIGS. 8-11 , it is seen that a third preferred embodiment of a trigger assembly 410 is provided. The trigger assembly 410 can be a direct replacement for a standard assembly. The trigger assembly 410 has a frame 420 , a sear 430 , a trigger 440 and a sear transfer bar 450 . Each of these components is similar to and has similar subcomponents as the like-named parts above. Specifically, the trigger 440 has a finger element 441 with a front 442 and a back. The user engages the front 442 of the finger element 441 while pulling the trigger 440 .
The trigger assembly 410 further has a safety 460 . Safety 460 is preferably a double safety, and accordingly engages at least two internal components (the sear 430 and the sear transfer bar 450 ) of the trigger assembly.
The safety 460 has a pivot 461 . The pivot 461 can comprise a pin or shaft, about which the safety 460 rotates. A control arm 465 is provided for toggling the safety 460 between a safe position and a ready position. The control arm 465 has an end with an end knob 466 . The end knob 466 can be screwed onto the end of the control arm 465 and be selectably positionable in front of the front 442 of the finger element 441 of the trigger 440 . The knob 466 can be affixed to the control arm 465 after the control arm is fed through the frame 420 . The control arm 465 can be justified for a left-handed shooter and for a right-handed shooter. An end key 467 is provided for accomplishing this, as described below. The key 467 preferably is formed from a generally right angle bend in the stock material, wherein the key 467 is generally perpendicular to the remainder of the arm 465 as best seen in FIG. 11 .
The safety further has a rotating body 470 . The body has a slot 471 there through for receiving the key 467 . The key 467 can engage the slot 471 from either direction depending upon whether the safety 460 is developed for left or right orientation.
A first lug 472 is provided on the body 470 for engaging the safety ear of the transfer bar 450 . A second lug 473 is also provided for engaging safety ear of the sear 430 . With the safety 460 in the safe position, lug 472 prevents the transfer bar from rotating (hence maintaining engagement between the sear engager of the transfer bar 450 and the sear contact of the sear 430 ), and lug 473 directly prevents the sear 430 from dropping. When the firearm is in the set position, the trigger assembly can be uncocked by placing the safety to the safe position. In this regard, lug 472 presses against ear of the bar 450 to rotate bar 450 about pivot away from the set position.
Two detents 474 and 475 are provided. A safety ball 480 , or simply a ball, is further provided. The ball 480 rests on a spring 481 that is within pocket in the spacer block. The ball engages detent 475 when the trigger assembly is not in the safety on position, and engages detent 474 when the trigger assembly is in the safety on position. The control arm 465 is used to effect the toggling between the detents 474 and 475 , wherein spring 481 is temporarily compressed to allow the ball to move between the detents. The control arm 465 can have a first position adjacent to and in front of the front 442 of the finger element 441 . In this regard, the control arm 465 of the safety interferes with operation of the trigger in addition to ball 480 engaging the first detent 474 . The control arm has a second position rotated away from the front of the finger element of the trigger wherein it does not interfere with the engagement of the trigger in addition to the ball 480 engaging the second detent 475 .
It is appreciated that the control arm 465 can be positioned selectably for left and right handed configurations.
Thus it is apparent that there has been provided, in accordance with the invention, a trigger assembly that fully satisfies the objects, aims and advantages as set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art 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 trigger may be pivotally connected to a frame at or near the top of the trigger. A sear transfer bar may be further provided and is pivotally connected to the frame. The pivot in the trigger is higher within the frame as compared to the pivot of the sear transfer bar. Two balls can be between the trigger and the sear transfer bar. The top of the sear transfer bar has a sear contact. Pulling the trigger in a first direction causes the trigger to rotate in a first direction. The sear transfer bar rotates under force of the trigger. The sear transfer bar and the trigger may rotate in opposite directions. The sear will drop when the sear contact of the transfer bar ceases engagement with the sear, causing the firearm to fire. The trigger assembly has a control arm extending beyond the trigger assembly frame.
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BACKGROUND AND SUMMARY
The present invention relates to a method, a device and a system in a vehicle for communicating a deviation of a measured actual vehicle parameter value from its corresponding predetermined value to a driver as well as a vehicle comprising such a device and such a system, and a computer readable medium comprising a computer program for performing such a method.
Modern vehicles comprise a plurality of devices and systems for communicating different values or warnings to a driver. Especially, the application of different driver assistance systems, as e.g. an ADAS system (advanced driver assistance system) are intended to assist the driver by providing a plurality of additional information, the driver is often not even able to be aware of. For example, the ADAS system provides data of a travelled road, e.g. whether the vehicle is approaching a curve or bend, or what kind of road is travelled (highway etc.). Even additional information on the road pavement can be communicated to the driver. Often the vehicle is also equipped with infra-red cameras and/or wireless communication possibilities gathering information provided on the road for example by sign posts or by remote navigation system providers. Also other environmental conditions, such as rain, wind, darkness, can be taken into account and be communicated to the driver. But also “simple” information, as for example the fact that a driver is exceeding a speed limit, can be communicated. Mostly, this information is communicated by warnings in order to attract the driver's attention.
From the article of Kumar, M., Kim, T., “Dynamic Speedometer: Dashboard redesign to discourage drivers from speeding”, CHI, Apr. 2-7, 2005, Portland, Oreg., USA (see also: hci.stanford.edu/research/speedometer/LBR-197-kumar.pdf), for example a speedometer is known which is adapted to visually distinguish the regions of the speedometer which are higher than a current speed limit. As the speed limit changes, the visualization on the display is updated accordingly. This relieves the driver of the task of waiting/searching for speed limit signs on the road to determine the current speed limit in effect. The disclosed speedometer can be instrumented to provide visual cues such as making the speedometer needle glow, changing the colour/illumination of the over-the-speed limit region of the speedometer, or changing the background of the dial itself when the driver exceeds a certain threshold over the speed limit. Additionally, an audio notification such as beeps of varying frequency and amplitude can be used, wherein the variation can be dependent on the excess over the speed.
The additional information provided to the driver is supposed to increase the safety of driver, passenger(s) and outside traffic participants, since knowing the vehicle's current situation may allow the driver/vehicle to prevent accidents. On the other hand the plurality of information and warnings can easily distract the driver's attention or even result in a complete neglect.
It is therefore desirable to provide a communication method, device and system which communicate information about vehicle related parameters to the driver of said vehicle and support the driver in driving said vehicle without the need of direct interaction.
According to aspects of the present invention, a communication method, a device and a system, as well as a vehicle and a computer and computer program product are provided.
An aspect of the invention is based on the idea that by (i) determining an amount of a deviation of an measured actual vehicle parameter value from its corresponding predetermined value, (ii) colour-coding said determined amount of deviation and (iii) communicating said amount of deviation to the driver by using said color code, the driver can be guided to the correct drive behaviour without direct warning.
For determining the amount of deviation, according to the invention it is preferred to use an algorithm which is based on a weighting function and which combines the difference between the measured actual value of the vehicle parameter and its corresponding predetermined value with a first weighting factor. The weighting factor is related to the vehicle parameter and can advantageously be at least one of (i) an additional vehicle parameter, e.g. weight, payload, braking power, and/or (ii) an environmental parameter, such as road conditions/characteristics, weather, distance to an obstacle etc. The result is color coded communicated to the driver and also gives an information about a necessity to act.
The predetermined value itself can be, as a preferred embodiment of the invention shows, a target value the measured actual vehicle parameter should have at a predetermined target time and/or a predetermined target location, and can also be weighted with a second weighting factor. Since the second weighting factor is also related to at least one additional vehicle parameter e.g. weight, payload, braking power, and/or at least one environmental parameter, such as road conditions/characteristics, weather, distance to an obstacle etc. the target value changes correspondingly.
According to another preferred embodiment, the predetermined target value is a calculated optimal value for the measured actual vehicle parameter at the time and/or the location of the actual measurement. The optimal value can be determined e.g. by a nominal function, such as an interpolation or an extrapolation between/from the measured actual vehicle parameter measured at an initial time and/or an initial location and/to a target value the measured vehicle parameter should have at a target time and/or a target location. The calculation of the optimal value can also take into account a second weighting factor which in turn is related to another vehicle parameter e.g. weight, payload, braking power, and/or an environmental parameter, such as road conditions/characteristics, weather, distance to an obstacle etc.
Consequently, the color coded information of the deviation of the measured actual vehicle parameter value and the optimal value can guide the driver to the correct driving behaviour.
In other words, if the actual measured value is the optimal value for the location the value is measured, the method according to the invention will not show any color coded information at all. Only, if the actual measured value of the vehicle parameter deviates from the calculated optimal value for the corresponding measurement location, the method according to the invention will show any colour-coded information to the driver.
Since, as explained above, this difference between the actual measured vehicle parameter value and the predetermined vehicle parameter value is a continuous function in time which usually will increase or decrease having positive values (in case the measured actual vehicle parameter value exceeds its predetermined value) or negative values (in case the measured actual vehicle parameter value is below its predetermined value) or zero (in case the measured actual vehicle parameter value is identical with its predetermined value) the corresponding color code will change continuously as well.
Preferably, the color code is communicated to the driver's peripheral vision so that the driver is not distracted from driving the vehicle by paying attention to a plurality of warnings. Especially, the communicated information can also be a combination of a plurality of system parameters without increasing the number of warnings.
The communication to the driver's peripheral vision can be achieved for instance by changing the color brightness, color saturation and/or color hue of a communication device, so that the communication device is more or less visible to the driver whereby also a necessity to react is communicated.
This continuous change causes fading in/fading out effects of the color coded information signal shown to the driver on the communication device. If he currently does not drive the vehicle in accordance with the correct way (i.e. the correct vehicle speed as a function of time) the warning signal according to the invention will be shown causing him to react. If he, as a preferred embodiment of the invention shows, decelerates or accelerates the vehicle, as the case may be, towards the optimal speed or the target speed the color coded signal will gradually fade out (change in brightness towards lower brightness values) or change its color hue e.g. towards green, thereby indicating that the driver is moving towards the correct driving behaviour. If he, contrary to such behaviour, is accelerating or decelerating the vehicle, as the case may be, away from the optimal speed or the target speed the color coded signal will gradually-fade in -(change in brightness towards higher brightness values) or change its color hue e.g. towards red. If and as long as the actual current vehicle parameter is either above or below the optimal speed or target speed it may under special circumstances happen that the color coded signal will not change at all depending on the weighting factors used. Since the first and/or second weighting factor/s is/are dependent on at least one additional vehicle parameter e.g. weight, payload, braking power, and/or at least one environmental parameter, such as road conditions/characteristics, weather, distance to an obstacle etc., the color coded signal usually is different for different vehicles and/or different times and/or different situations.
It is also possible to use the invention for other vehicle parameters, as e.g. RPM (Revolutions Per Minute) or fuel consumption. Preferably, the vehicle parameter is related to parameters provided by a driver's assistance system, as for example an ADAS system, and/or by a remote system e.g. a customer defining the driving behaviour of his drivers, for example a recommendation for travelling along with a green wave.
The invention can advantageously be used for vehicle parameters which are suitable for being communicated by a gauge or a meter to the driver. The color coded can preferably be implemented by changing the illumination, e.g. the background light of the gauge/meter or by colouring the gauge's/meter's display. The illumination/colouring can be performed for example by the use of LED, or the speedometer itself is already designed as LCD panel.
Preferably, the color coded is provided by increasing/decreasing the brightness or hue of a color of e.g. of the gauge's/meter's background light. Dependent on the weighted amount of deviation and whether or not that weighted amount is increasing or decreasing over the time the background light is
fading in (i.e. gradually increasing its brightness, hue, or intensity or gradually changing its color for instance in a range from green over yellow to red or, alternatively, from normal display background light (or to a state without any background light-)-over yellow-to-red) or fading out (i.e. gradually decreasing its brightness, hue, or intensity or gradually changing its color for instance in a range from red over yellow to green or, alternatively, from red over yellow to the normal background light (or to a state without any background light)) and is therefore recognizable by the driver's peripheral vision. It is therefore not recognized as “real” warning, and consequently the driver is not distracted by it. Because of the smooth fading in/fading out it is also possible to communicate the “warning” quite late without causing panic reactions by the driver. It also provides an easy retrofitting possibility for existing vehicles.
According to a further preferred embodiment of the invention color hue, brightness and/or saturation are/is also adaptable to ambient light. This has the advantage that a deterioration of the visibility due to daylight or other bright ambient light or distracting reflections of the inventive communication device in a windscreen during night-time or driving in a tunnel can be reduced. Especially, since the peripheral vision of the driver is addressed, reduced visibility or distraction by reflections can result in a disregard of the information. Preferably, the adaptation can be performed manually or automatically. The actual ambient light can preferably be measured with the help of optical sensors.
According to another preferred embodiment, only a part of the gauge/meter is illuminated/coloured, particularly that part which exceeds/succeeds the predetermined value. That means for example for the above described embodiment of the bend speed warning that that part of the speedometer is coloured that is between the predetermined speed for the bend and the measured actual speed shown at the speedometer (exceeding the predetermined speed). The weighted amount of the deviation from the measured actual value and the predetermined value can then again be communicated by fading of the color brightness, saturation or hue. It is also possible to increase/decrease the illuminated/coloured part of the gauge/meter to indicate the amount of deviation.
Further advantages and preferred embodiments are defined by the description and/or the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following the invention is described in more detail by means of preferred embodiments. The described preferred embodiments are exemplary only and should not be used to restrict the invention thereto.
The figures show:
FIGS. 1A-1D : a first embodiment of the inventive device;
FIGS. 2A-2C : a simulation of a preferred embodiment of the inventive method; and
FIGS. 3A-3F : different scenarios of a preferred embodiment of the inventive method.
DETAILED DESCRIPTION
In the following the invention is described for a preferred embodiment, wherein the vehicle parameter is the vehicle's speed which is communicated to a driver by means of a speedometer. For explaining the invention's advantages, a situation is discussed wherein a vehicle is approaching a bend on the road, and the measured actual speed value of the vehicle is higher than a predetermined speed value which would condition the vehicle for being able to drive through the bend ahead in the wanted (safe) way. The predetermined speed value of the vehicle is determined for instance by a driver assistance system, particularly an ADAS system. But it can also be determined by a remote system for example an on-line navigation system or a remote road driving guidance system.
In principle there are two possibilities to define the predetermined vehicle parameter value:
1. One approach is that a driver assistance system, such as an ADAS system, calculates a target speed with which the vehicle can drive safely through a bend ahead. This target speed—can change dependent on other vehicle parameters- e.g. payload and/or environmental parameters such as weather conditions (smart ADAS). In this case the target speed can also be monitored and changed in order to avoid accidents caused by fast changing road conditions e.g. freezing rain. But it is also possible that the target speed is a constant once stored in a database of the driver assistance system (simple ADAS). This target speed is then taken as predetermined speed.
The difference between the measured actual speed value and the target speed value is constantly re-calculated and the result is weighted by a weighting factor. The weighting factor weights the difference between the measured actual speed and the target speed and is, in this case, dependent on the distance to the bend, only. Of course, the weighting factor can take into account further vehicle parameters or environmental parameters, as discussed above.
That means, for example, if a vehicle is travelling with 80 km/h and approaches in 500 m a bend with a defined target speed of 40 km/h at the bend, a warning is not necessary, even if the difference between measured actual speed and target speed is high, as the distance'to the bend is very long. But in case the bend is only e.g. 150 m ahead, a warning would be shown. In case the distance to the bend is 500 m, the weighting factor might be set to “0”, so that calculating a very simple weighting function by multiplying the weighting factor with the difference would give “0” as result meaning no warning is necessary. But if the distance to the curve has reduced e.g. to 150 m, the weighting factor can be set to another value different from “0”, so that the result of the weighting function gives a certain amount which can be color coded. Dependent on the reduced distance, the weighting factor can be increased given higher and higher amounts which result in more visible colourations of the speedometer. In case the driver reduces its speed also the difference between the measured actual speed and the target speed reduces, which in turn also reduces the result of the weighting function leading to a less visible colouration. But in case the deceleration is not sufficient the weighting factor can be set to a very high value resulting in the same or yet in a more visible colouration.
2. The other approach also starts with the ADAS system determining a target speed, but then the ADAS system or a calculation unit, calculates optimal speed values for each distance to the bend. With other words, an optimal deceleration curve is determined for the vehicle. This optimal deceleration curve can be achieved e.g. by interpolation or extrapolation between/from an initially measured speed and/to the determined target speed. The optimal deceleration curve defines for each distance to the bend an optimal speed, wherein the optimal speed can also be weighted by additional vehicle parameters such as payload, braking power etc. and/or environmental parameters such as road conditions, weather conditions etc.
Then, the difference between the measured actual speed and the corresponding optimal speed is calculated and the result is color coded communicated to the driver.
As explained above, the information is only visible to the driver if the deceleration behaviour of the driver deviates from the optimal deceleration function.
The invention is not limited to the bend speed warning. It is also possible to inform the driver on other requirements for adjusting the speed e.g. in order to travel along with a green wave, which in turn can reduce fuel consumption, or approaching a preceding vehicle, or approaching a junction where a stop and subsequent turn to a different road is necessary. Thus, speed adjustment comprises not only a decelerating process but can also mean an acceleration. Additionally, a speed adjustment can be necessary if the weather conditions, road conditions, and/or road characteristics are changing or simply if a speed limit is set. That means that the invention can be implemented in all such cases where a speed adjustment should be communicated to the driver.
Moreover the invention can also be used in all other cases where a determined driving behaviour of a driver is required. For example, if the driver is operating the vehicle engine with RPM values above or below a recommended predetermined revolution -range, the invention can be used to guide the driver to the recommended operating behaviour.
On the other hand the invention is also usable for other vehicle parameters, particularly for parameters which are suited to be communicated by means of a gauge or meter, such as tire/oil/breaking-fluid pressure and/or for all parameters a communication of guidance is required.
FIGS. 1A-1D show a speedometer 2 comprising a speedometer needle 4 and a speedometer dial 6 . The speedometer 2 can be an individual solid instrument but it is also possible that the speedometer is only displayed on a monitor, wherein the monitor can display a certain selection of instruments in the vehicle or all instruments in the vehicle and thereby forms a vehicle's dashboard. But the monitor can also display the speedometer only, and can even have the same shape as a traditional analogue speedometer. In contrast to the speedometer shown in FIG. 1 , the speedometer can also have all known other shapes. It is even possible that the speedometer does not comprise a speedometer needle and a dial at all, but communicates the speed by digits only.
The speedometer 2 is at least partially coloured and/or illuminated by any suitable means, as for example an additional coloured dial which is mounted in front of the speedometer dial 6 or by means of illumination devices such as LEDs. It is also possible to use a speedometer with background illumination of the dial 6 and make the speedometer dial transparent in the desired region, e.g. by shading the other region by the help of a non-transparent additional dial. In case the speedometer is displayed it is also possible to adjust the color hue and/or color brightness and/or the color saturation in the corresponding regions by an appropriate control of the monitor. The coloured/illuminated region of the speedometer is referenced by reference number 8 .
According to the invention, size, color brightness, color hue and color saturation of the coloured region 8 depend on a weighted amount of a deviation of a measured actual-speed-value-frøm-a predetermined speed value. The measured actual speed value in FIG. 1A-1C is exemplarily given by roughly 80 km/h and in FIG. 1D by 35 km/h. In the illustrated embodiments a target speed value is 40 km/h. Consequently, the driving behaviour recommendation communicated to the driver is a deceleration in the cases of FIGS. 1A to 1C but is an acceleration in case of FIG. 1D . Acceleration can be desired if e.g. the vehicle should travel along the road with a green wave, i.e. without being forced to stop due to red traffic lights located along the road the vehicle is supposed to travel.
In FIG. 1A a region 8 of the dial 6 of the speedometer 2 is continuously illuminated/coloured, whereby the region 8 corresponds to that region at the dial 6 which exceeds the target speed value 40 km/h. But it is also possible that only a part of the region 8 is illuminated/coloured, e.g. in form of a ring illuminating/colouring the dial numbers only which are located in that region 8 .
FIG. 1B shows another embodiment of a coloured/illuminated speedometer, wherein the speedometer is illuminated/coloured in segments 8 a - 8 g . The segments 8 e - 8 g exceeding the measured actual speed value 80 km/h are illuminated/coloured with a different color hue, or a different brightness or color saturation than the segments 8 a - 8 d between the target speed value 40 km/h and the measured actual speed value 80 km/h.
But it is also possible that only that region 8 between the measured actual speed value 80 km/h and the target speed value 40 km/h is illuminated/coloured as illustrated in FIG. 1C .
In FIG. 1D a region 8 of the dial of the speedometer 2 is illuminated/coloured, whereby the region 8 corresponds to that region at the dial 6 which is below the target speed value 40 km/h. In this scenario the measured actual speed of the vehicle is ca. 35 km/h which means it is below the target speed value 40 km/h. In such a case the region 8 of the speedometer is illuminated/coloured covering speed values from 0 km/h to the target speed value of 40 km/h. The region 8 can be illuminated in a way similar the situation described in connection with FIG. 1A-1C where the measured actual speed value exceeds the determined optimal speed value or the target speed value. But it is also possible that color hue, color brightness and/or color saturation are different for both situations (exceeding/being below the target/optimal speed value). For example it is possible that the illumination in case the measured actual speed value exceeds the target speed value is in red, but in case the measured actual speed value is below the target/optimal speed value the illumination is in green.
Communicating the fact that the measured actual speed is below the target speed is particularly preferred in case the driver wants to travel along a green wave or wants to travel a highway with a determined speed. Since it is not always desired to show the information that the measured actual speed value is below the target speed—for example in case the driver wants to drive slower through a bend as it is suggested by the system (e.g. due to an individual feeling for driving safely) or wants to stop before the bend—it is possible to adapt the method so that a deviation is only shown in case the target speed/optimal speed is exceeded. But it is also possible that the driver himself can decide from case to case that the information that his actual measured speed is below the target/optimal speed is shown. This can be achieved for example by providing an activation/deactivation element e.g. a button which can be pressed by the driver.
The general idea behind the embodiments depicted in FIG. 1A-1D is to detect any deviation of the measured actual speed of the vehicle from the determined optimal speed or the target speed (i.e. deviations with positive or negative values) and to encourage the driver to drive the vehicle in accordance with the determined optimal speed or the target speed by visualizing such deviations in the way described above.
All illustrated embodiments of colouration/illumination can be combined with each other so that for example, the colouration/illumination of the speedometer shown in FIG. 1A can also be a segmented.
FIGS. 2A-2C show a situation in which the driver does not reduce the speed of the vehicle in accordance with the decreasing distance to bend ahead. In this illustrated example, the color brightness increases since the driver does not reduce the speed of the vehicle correspondingly.
FIG. 2A shows a vehicle 10 approaching a bend 12 with a speed of 80 km/h. A driver assistance system defines the target speed value for the vehicle at the bend to 40 km/h. A calculation unit (not shown) in the vehicle 10 or the driver assistance system itself calculates a weighting function with which the difference between the measured actual speed value (80 km/h) and the target speed value (40 km/h) is weighted by a weighting factor, for example the distance d of the vehicle 10 to the bend 12 . The distance d to the bend can be determined for example by GPS.
As explained above and with reference to FIG. 2A , at a distance d 1 to the bend 12 , the calculation of the weighting function or the deviation of the measured actual speed to the optimal speed gives that the driver should decelerate the vehicle 10 in order to be able to drive safely through the bend 12 ahead. Correspondingly, a control unit (not shown) controls the colouration/illumination of the speedometer 2 so that that region 8 is coloured/illuminated which exceeds the predetermined speed value of 40 km/h.
In the illustrated example, with reference to FIG. 2B , the driver has reduced the speed of the vehicle 10 from 80 km/h to 65 km/h while driving the vehicle 10 from the first point on the road at a distance d 1 to the bend 12 ahead to a second point on the road at a (shorter) distance d 2 to the bend 12 ahead, i.e. by for example releasing the accelerator. However a continuously ongoing re-calculation of the weighting function or of the difference between the measured actual speed and the optimal speed gives at the second point of the road at distance d 2 to the bend 12 ahead that the current deceleration rate is not sufficient to be able to drive safely through bend 12 . Therefore, the brightness of the illuminated speedometer region 8 is increased accordingly although the driver had reduced the measured actual speed of the vehicle from 80km/h to 65 km/h.
Due to the increasing or increased brightness of the region 8 of the dial 6 of the speedometer 2 in the situation as depicted in FIG. 2B the driver can now realize that a further action, as for example operating a brake, is necessary to reach the recommended target speed at the bend 12 ahead.
As seen in FIG. 2C , the driver eventually has reduced the measured actual speed of the vehicle 10 to the target speed value at the bend of 40 km/h with the deceleration process guided by the fading in/fading out of the illuminated region 8 of the speedometer and therefore drives safely through the bend 12 .
FIGS. 3A to 3F shows different scenarios of how the calculation of the weighting function or the difference to an optimal deceleration curve influences the color coded result communicated to the driver.
Depending on the result of the calculation of the weighting function or the difference between the measured actual speed and the optimal speed, the brightness and/or the saturation and/or the hue of the colour(s) are adapted. That means for example in case the driver travels with a very high speed but is still far away from the bend ahead and drives a vehicle without payload, the color is less bright than in the same case with the vehicle having a payload or driving in snow.
FIGS. 3A to 3F show a vehicle 10 approaching a curve 12 , and a speedometer 2 with a speedometer needle 4 and a colorable region 8 , wherein the colorable region 8 is coloured according to the color coded deviation amount. The target speed for the bend ahead is, as before, 40 km/h.
In FIG. 3A , the distance d 1 of the vehicle 10 to bend 12 is long. Even if the difference between the measured actual speed (85 km/h) and the target value of 40 km/h is quite large, the weighting factor is still low (because of the long distance). Consequently, the colouration of region 8 is almost not visible.
With reference to FIG. 3B , although the driver has reduced its speed from 85 km/h to 65 km/h, the colouration of region 8 is more visible than in FIG. 3A , as the relatively short distance d 2 to bend 12 and the insufficient deceleration increases the weighting factor.
FIG. 3C shows the same situation as FIG. 3B , but wherein the driver has not reduced his speed at all. The short remaining distance d 2 to the bend 12 and the very high deviation of the measured actual speed of the vehicle from the optimal speed value or target speed value result in a clearly visible colouration of region 8 .
FIGS. 3D and 3E show the same situation as FIGS. 3A and 3B in bad weather condition (for instance snow). The same distance d 1 to bend 12 and the same speed of 85 km/h results in a clearly visible colouration of region 8 , because the weighting factor is set to a higher value due to the bad weather condition. Accordingly, the deceleration to 65 km/h as shown in FIG. 3E is not sufficient for the distance d 2 and result in a strongly coloured region 8 .
Even a deceleration to almost 40 km/h, as shown in FIG. 3F , still results in a visible colouration due to-the increased weighting factor because of the bad weather condition.
Provided that the driver drives reasonable and is willing to follow a guidance, the inventive method can communicate a recommended driving behaviour without direct interaction with the driver. Therefore, it is possible to communicate even highly important parameters without warning a driver directly.
The invention is not restricted to applications in vehicles as described above but can also be used in applications for ships, air planes, construction-site machines, motorbikes, etc.
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A method, a device and a system for communicating in a vehicle at least one deviation of a measured actual vehicle parameter value from its predetermined value to a driver involve determining an amount of the deviation, color-coding the amount of deviation, and communicating the amount of deviation to the driver by using the color-code. Determining the amount of deviation includes weighting a calculated difference between the measured actual vehicle parameter value and the predetermined vehicle parameter value with a weighting factor. A vehicle or more particularly a truck may include such a device and such a system and a computer programmed for performing such a method and computer readable medium comprising a program for performing such a method can be provided.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a locking element for a quick connector.
2. Description of the Related Art
A locking element is known for example from US 2003/0137148 A1. The prior one-piece, U-like locking element is provided with means for effecting a snap connection with a receiving element of a quick connector, and with locking means which in a locked position can be brought into engagement with a retaining ring configured on an insertable element of the quick connector. The means for effecting a snap connection are configured as radially outwardly projecting noses formed onto outer arms oriented parallel to each other. The locking means are configured in the form of two mutually opposite projections disposed inwardly of the outer arms. The prior locking element is displaceably mounted in a clearance configured in the receiving element of the quick connector.
A further one-piece locking element for a quick connector is known from DE 101 15 399. This one-piece locking element can be mated onto a quick connector and is provided with means for effecting a snap connection with a receiving element of a quick connector, the locking element being displaceable perpendicularly to the longitudinal direction of the quick connector between a locked position that protects an insertable element of the quick connector against accidentally slipping out and a released position in which the insertable element can be withdrawn from the receiving element.
SUMMARY OF THE INVENTION
The present invention provides a locking element for a quick connector which, as a supplemental, particularly also retrofittable, locking element is distinguished by secure attachment to a receiving element of the quick connector and by ease of use.
By virtue of the fact that the inventive locking element is configured as two-part, with a matable element and an actuating element, the matable element, due to the specific configuration, being able, as an additional component besides a U-type or ring-shaped locking element already present on the quick connector, reliably to be brought into engagement forwardly with the receiving element of the quick connector, taken in the direction of insertion of the insertable element, and the actuating element being mounted in the matable element and thus independently of the configuration of the receiving element of the quick connector, operationally reliable fixation and ease of use of the additional lock are obtained.
The provision of a cover plate provides an actuating surface configured on a quick connector and serving to release an insertable element, thereby substantially reducing the risk of accidental loosening in the connection made by the quick connector.
In one form thereof, the present invention provides a locking element for a quick connector, including means for effecting a snap connection ( 18 , 19 ) with a receiving element ( 1 ) of a quick connector and comprising locking means ( 22 , 23 , 25 , 26 ) which in a locked position can be brought into engagement with a retaining ring ( 2 ) configured on an insertable element ( 3 ) of said quick connector, characterized in that present as a separate component is a matable element ( 11 ) on which said means for effecting a snap connection ( 18 , 19 ) are configured and which comprises, disposed opposite said means for effecting a snap connection ( 18 , 19 ), a bearing wall ( 12 ) which in an arrangement of being mated onto said receiving element ( 1 ) bears against the front side of said receiving element ( 1 ), taken in the direction of insertion of said insertable element ( 3 ), and in that present as an additional separate component is an actuating element ( 15 ) that is in engagement with said matable element ( 11 ) and is mounted in said matable element ( 11 ) so as to be displaceable between a released position and a locked position and is equipped with said locking means ( 22 , 23 , 25 , 26 ).
BRIEF DESCRIPTION OF THE DRAWINGS
The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a partially cut-away perspective view of an exemplary embodiment of an inventive locking element mated onto a quick connector in a released position;
FIG. 2 is a perspective view of the exemplary embodiment according to FIG. 1 ; and
FIG. 3 is a partial cut-away perspective view of the exemplary embodiment according to FIG. 1 mated onto a quick connector in a locked position.
Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplifications set out herein illustrate embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed.
DETAILED DESCRIPTION
FIG. 1 is a partially cut-away perspective view of an elongated, cylindrically configured receiving element 1 of a quick connector, which element can be connected to an end (not shown in FIG. 1 ) of a conduit of a fluid carrying system. To sealingly connect the receiving element 1 to an insertable element 3 that is part of the quick connector and is configured as a retaining ring 2 , a first sealing ring 4 , a second sealing ring 5 and an intermediate sealing ring 6 disposed between said sealing rings 4 , 5 are present in a receiving space 7 of the receiving element 1 . A spacing ring 9 disposed adjacent the side of second sealing ring 5 facing the insertion side 8 serves to hold sealing rings 4 , 5 and intermediate ring 6 in place on the side of receiving space 7 facing away from insertion side 8 .
Also illustrated in FIG. 1 is an exemplary embodiment of an inventive locking element 10 in an arrangement wherein it is mated onto the receiving element 1 of the quick connector. The locking element 10 is provided with a matable element 11 that can be mated onto the receiving element 1 and has a bearing wall 12 , which in the mated-on arrangement of FIG. 1 bears against the front side of the receiving element 1 , taken in the direction of insertion. The locking element 10 is further configured with a front wall 13 that is spaced apart from the bearing wall 12 oppositely to the direction of insertion. Both bearing wall 12 and front wall 13 have a central clearance through which insertable element 3 can be passed, such that guide rails 14 are formed edgewise between bearing wall 12 and front wall 13 . The locking element 10 further comprises an actuating element 15 , which in the mated-on arrangement of the locking element 10 can be displaced, guided in the guide rails 14 , relative to the matable element 11 perpendicularly to the direction of insertion of insertable element 3 into receiving element 1 , as will be explained in more detail below.
FIG. 2 is a perspective diagram of the inventive locking element 10 depicted in FIG. 1 in the arrangement wherein it is mated onto the receiving element 1 , looking toward the side of the bearing wall 12 facing away from front wall 13 . It can be seen from FIG. 2 that the locking element 10 has a first side wall 16 and a second side wall 17 , which are affixed to the side of bearing wall 12 facing away from front wall 13 . Configured as snap connection means at the ends of side walls 16 , 17 facing away from bearing wall 12 are radially inwardly directed projections 18 , 19 , which, in an arrangement wherein the locking element 10 is mated onto a receiving element 1 , engage behind the side of the receiving element 1 disposed rearwardly in the direction of insertion of insertable element 3 into receiving element 1 , and thereby, in combination with bearing wall 12 belonging to matable element 11 and disposed forwardly in the direction of insertion of insertable element 3 into receiving element 1 , releasably lock matable element 11 on receiving element 1 . To achieve the firmest possible connection to receiving element 1 , side walls 16 , 17 are connected to each other via a bridge portion 20 usefully formed onto the respective back ends of said side walls 16 , 17 .
It can further be appreciated from FIG. 2 that the actuating element 15 is provided with a slightly curved cover plate 21 that extends from the plane of bearing wall in the direction of side walls 16 , 17 , and with a first arm 22 and a second arm 23 , which are mounted substantially at right angles to cover plate 21 and engage in the guide rails 14 , such that the actuating element 15 is displaceable perpendicularly to matable element 11 between an extended, released position depicted in FIG. 2 and a retracted, locked position. Arms 22 , 23 are each provided on their respective sides adjoining the clearance 24 with a reinforcing rib 25 , 26 that extends in the circumferential direction and projects in the direction of side walls 16 , 17 , and on which in turn are configured endwise-disposed abutment noses 27 also projecting in the direction of side walls 16 , 17 .
Finally, it can be appreciated from the representation according to FIG. 2 that configured on the matable element 11 in the region of guide rails 14 and arms 22 , 23 are snap connection means in the form of snap lugs 28 and snap indentations 29 that engage in one another both in the released position illustrated in FIG. 2 and in the locked position, and in both of these positions protect the actuating element 15 to a certain degree against forces operating in the displacement direction.
FIG. 3 is a partially cut-away perspective view of the exemplary embodiment according to FIG. 1 , in an arrangement wherein it is mated onto a quick connector with the actuating element 15 in the retracted, locked position, and of the quick connector with an insertable element 3 properly inserted in receiving element 1 . In this arrangement of receiving element 1 and insertable element 3 , retaining ring 2 is held in place by an annular retaining spring 30 , which surrounds insertable element 3 and which comprises radially inwardly extending retaining lugs 31 that engage behind the retaining ring 2 . To release insertable element 3 , retaining spring 30 must be deformed by the exertion of pressure on a release side 32 to such an extent that the engagement between retaining ring 2 and retaining lugs 31 is released and insertable element 3 can be removed from receiving element 1 against the direction of insertion.
Direct access to the release side 32 is prevented, however, in the locked position of actuating element 15 , by the fact that release side 32 is covered by cover plate 21 , thus protecting the quick connector against accidental disengagement of the connection between receiving element 1 and insertable element 3 . Nevertheless, should the connection between receiving element 1 and insertable element 3 be accidentally released, for example by the exertion of pressure on the release side 32 due to the accidental insertion of an elongated object, such as the blade of a screwdriver, between cover plate 21 and release side 32 , or due to wear on the retaining ring 2 or the retaining lugs 31 , the arms 22 , 23 with their reinforcing ribs 25 , 26 , which are disposed relatively closely adjacent a shaft segment 33 of insertable element 3 , form an additional abutment that holds insertable element 3 in receiving element 1 when actuating element 15 is in the locked position.
It can further be appreciated from FIG. 3 that the abutment noses 27 extend into the receiving space 7 and thereby prevent actuating element 15 from being removed completely from the guide rails 14 . In this way, the movable actuating element 15 is also held captive in the mated-on arrangement of locking element 10 .
It is understood from the foregoing description that the specific shape of the matable element 11 and of the actuating element 15 is adapted to the particular conformation of the receiving element 1 of the quick connector.
While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
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A locking element for a quick connector is provided with a matable element releasably connectable to a receiving element of the quick connector. An actuating element is in engagement with the matable element and is mounted within the matable element such that it is displaceable between a released position and a locked position. The actuating element includes a locking device that can be brought into engagement with a retaining ring on an insertable element of the quick connector in an arrangement wherein the locking device is mated with the receiving element in the locked position. Secure attachment of the locking element to the quick connector and ease of use are thereby achieved.
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BACKGROUND OF THE INVENTION
The present invention relates to a ferromagnetic resonator utilizing ferromagnetic resonance and suitably applicable to microwave equipments such as, for example, microwave filters and microwave oscillators.
There has been proposed a ferromagnetic resonator such as, for example, a filter, utilizing the ferromagnetic resonance of a ferrimagnetic yttrium-iron-garnet (hereinafter abbreviated to "YIG") thin film device formed by growing an YIG thin film through a liquid phase epitaxial growth process (hereinafter referred to as "LPE process") on a gadolinium-gallium-garnet (hereinafter abbreviated to "GGG") substrate, and by selectively etching the YIG thin film in a predetermined pattern. Filters of such a kind are disclosed, for example, in U.S. Pat. No. 4,547,754.
The microwave equipment such as a filter employing such an YIG thin film device has advantages in that the Q of resonance in the microwave band is high, the construction is compact, the LPE process and the lithographic selective etching process is suitable for mass-production, and the use of a thin film facilitates forming microwave integrated circuits employing microstrip lines as transmission lines.
As is well known, it has been usual to use YIG single crystal spheres for the ferromagnetic resonator of a microwave equipment utilizing ferromagnetic resonance. The YIG single crystal ball has advantages in that a magnetostatic mode is difficult to establish and the single resonance mode is established in a uniform precession mode. However, the YIG single crystal sphere has problems in processing and mass production. Accordingly, the development and practical application of the ferromagnetic resonator employing a YIG thin film, namely, a ferrimagnetic thin film, has been desired.
Incidentally, the magnetostatic mode established when a DC magnetic field is applied perpendicular to the surface of a ferrimagnetic disk is analyzed in Journal of Applied Physics, Vol. 48, pp. 3001-3007, July, 1977, in which modes are represented by (n, N)m, where n is the number of nodes along the circumferential direction, N is the number of nodes along the diameter, and m-1 is the number of nodes in the direction of thickness. When the high-frequency magnetic field is satisfactorily uniform over the entire range of the ferromagnetic disk, modes of (1, N) 1 are principal magnetostatic modes. In constructing a microwave filter or a microwave oscillator, the main mode (1, 1) 1 of the (1, N) 1 system is employed and the rest of the magnetostatic modes are regarded as spurious modes, namely, spurious response or spurious oscillation. For example, the aforementioned U.S. Pat. No. 4,547,754 proposes a resonator employing a ferrimagnetic YIG thin film provided with an annular groove, and a resonator employing a ferrimagnetic YIG thin film having a central portion of a thickness smaller than that of the peripheral portion thereof, both designed to avoid the spurious response mode.
On the other hand, since the operating frequency of the ferrimagnetic thin film resonator can be varied over a wide range by varying the magnetic field to be applied thereto, the ferrimagnetic thin film resonator is applied, for example, to variable-frequency microwave oscillators and variable-frequency microwave filters. In such application, however, the unloaded Q of the spurious mode increases together with the unloaded Q of the main mode with frequency, and hence the spurious mode cannot be ignored. Such a behavior of the ferrimagnetic thin film resonator is due mainly to the distribution of the exciting magnetization.
As shown in FIG. 23 by way of example, in the exciting method shown in U.S. Pat. No. 4,547,754, a strip line, namely, a transmission line 3, having one end connected to a grounding conductor 2, and having a uniform thickness, a uniform width and a uniform impedance is disposed across a disk-shaped ferrimagnetic thin film 1 so as to be coupled magnetically with the ferrimagnetic thin film 1. Supposing that the direction along the transmission line 3 is an x-direction, the direction along the surface of the ferromagnetic thin film 1 and perpendicular to the x-direction is the y-direction, the distance between the grounded end of the transmission line 3 and the ferrimagnetic thin film 1 is l 1 , and the length of a portion where the ferromagnetic thin film 1 and the transmission line 3 overlap with each other is l 2 , a magnetic field Hy generated by a current i rf along the y-direction is substantially uniform when l 1 ≦x≦l 1 +l 2 .
Calculated distributions of magnetization for modes (1, N) 1 (N=1, 2 and 3) over the ferrimagnetic thin film 1 in the state of magnetic resonance are shown in FIG. 24. These distributions of the magnetization are the same with respect to any diametrical direction.
In the consideration of the magnetization distribution of the magnetic field applied to the ferrimagnetic thin film 1 in this construction, when a high-frequency current i rf is supplied, a standing wave Ix is expressed by
Ix=i.sub.rf cos (2πx/λg) (1)
where λ g is the wavelength on the transmission line 3. When the y-component of the magnetic field generated by the current i rf is expressed by Hy(x), Hy(x) ∝ Ix. That is,
Hy(x) ∝ i.sub.rf cos (2πx/λg) (2)
Therefore, at a position x<<λ g /4, namely, a position near the grounded end of the transmission line 3 where x is nearly zero, Hy(x) is practically constant. In a range where x≦λ g /4, Hy diminishes along a cosine curve to zero at x=λ g /4.
Thus, when the frequency of i rf is low, namely, when λ g is comparatively large, Hy is substantially constant along the transmission line 3, and, when the frequency of i rf is comparatively high, namely, when λ g is comparatively small, the grounded end and opposite end of the ferromagnetic thin film 1 are different in the intensity of magnetic field from each other.
OBJECT AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved ferromagnetic resonator.
It is another object of the present invention to provide a ferromagnetic resonator effectively to suppress spurious response.
According to one aspect of the present invention, there is provided a ferromagnetic resonator which comprises a ferrimagnetic thin film, a transmission line coupled to the ferrimagnetic thin film, and a bias magnetic field means applying a bias magnetic field perpendicular to a major surface of the ferrimagnetic thin film: the transmission line generates a magnetic field having distribution similar to magnetization distribution in a main mode of perpendicular ferrimagnetic resonance of the ferrimagnetic thin film.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a ferromagnetic resonator, in a preferred embodiment, according to the present invention, showing the relation between a ferromagnetic thin film and a transmission line;
FIG. 2 is a fragmentary sectional view of the essential portion of the ferromagnetic resonator of FIG. 1;
FIGS. 3 and 4 are plan views showing the relation between a ferrimagnetic thin film and a transmission line in further embodiments of the present invention, respectively;
FIGS. 5A, 5B and 5C are sectional views of ferromagnetic thin films according to the present invention, respectively;
FIGS. 6, 7 and 8 are diagrams showing the reflection characteristics of ferromagnetic resonators according to the present invention, respectively;
FIGS. 9 and 10 are diagrams showing measured insertion losses of ferromagnetic resonators according to the present invention, respectively;
FIGS. 11 and 12 are graphs showing the measured dependence of insertion loss in the transmission line on the ratio a/b of the transmission line for frequencies in the main mode and in the spurious mode, respectively;
FIGS. 13 and 14 are diagrams showing measured insertion losses in the transmission lines of ferromagnetic resonators according to the present invention, respectively;
FIGS. 15 and 16 are enlarged views of encircled portions in FIGS. 13 and 14, respectively;
FIGS. 17, 18 and 19 are fragmentary sectional views of the essential portions of ferromagnetic resonators, in further embodiments, according to the present invention, respectively;
FIGS. 20, 21 and 22 are a sectional view, a plan view of the essential portion, and an exploded perspective view, respectively, of a variable-frequency microwave filter incorporating the present invention;
FIG. 23 is a plan view of a prior art ferromagnetic resonator;
FIG. 24 is a diagram showing a magnetization distribution of assistance in explaining the conventional exciting method;
FIGS. 25 and 26 are diagrams showing the reflection characteristics of a conventional ferromagnetic resonator;
FIGS. 27 and 28 are diagrams showing measured insertion losses of a conventional ferromagnetic resonator;
FIGS. 29 and 30 are diagrams showing measured insertion losses of a conventional ferromagnetic resonator; and
FIGS. 31 and 32 are enlarged views of encircled portions in FIGS. 29 and 30, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A ferromagnetic resonator according to the present invention comprises a ferrimagnetic thin film, and a transmission line coupled with the ferrimagnetic thin film and capable of producing a high-frequency magnetic field distribution corresponding to a magnetization distribution in the main mode of perpendicular magnetic resonance of the ferrimagnetic thin film.
According to the present invention, a magnetic field distribution in the transmission line corresponds to a magnetization distribution in the objective mode of the ferrimagnetic thin film, namely, the main resonance mode of uniform modes. Accordingly, the ferromagnetic thin film and the transmission line are coupled weakly in modes of higher order other than the objective mode, namely, in spurious modes, so that spurious resonance is suppressed.
A ferromagnetic resonator, in a first embodiment, according to the present invention will be described with reference to FIG. 1.
A ferrimagnetic thin film 1 is formed of an YIG thin film in the shape of a disk. A transmission line 3, namely, a strip line, is extended diametrically across the ferrimagnetic thin film 1 and is coupled magnetically with the ferrimagnetic thin film 1. In this embodiment, the transmission line 3 is 50 Ω in impedance and 1.22 mm in width W. Recesses 4 are formed in the transmission line 3 at the opposite ends thereof so as to face the peripheral portions of the ferrimagnetic thin film 1, respectively. Parallel high-impedance portions 5 each having a width Ws of 0.171 mm and high impedance of 100 Ω are formed on the opposite sides of each recess 4.
Referring to FIG. 2 showing a resonator incorporating the ferromagnetic thin film 1 in a section, the resonator is formed in a suspended substrate strip line construction which is generally shown in U.S. Pat. No. 4,679,015. The YIG ferrimagnetic thin film 1 is formed by growing YIG in a thin film on a nonmagnetic substrate 6, such as a GGG substrate, and by forming the YIG thin film through a photolithographic process in a predetermined pattern, namely, a disk shape in this embodiment. The transmission line 3 having a necessary pattern as described with reference to FIG. 1 is formed on an insulating substrate 7, such as a Si02 substrate. The transmission line 3 is formed by depositing the insulating substrate 7 with a metal layer through a vacuum evaporation process or a sputtering process, and by etching the metal layer in the predetermined pattern through a photolithographic process.
Then, the GGG nonmagnetic substrate 6 and the insulating substrate 7 are placed one over the other so that the ferrimagnetic thin film 1 and the transmission line 3 are coupled magnetically. The assembly of the GGG nonmagnetic substrate 6 and the insulating substrate 7 is held between an upper conductor 8 and a lower conductor 9 with air gaps 50a and 50b between the transmission line 3 and the upper conductor 8 and between the nonmagnetic substrate 6 and the lower conductor 9, respectively. As described with reference to FIG. 1, the transmission line 3 is connected electrically at one end thereof to the lower conductor 9 serving also as a grounding electric conductor 2.
In the ferromagnetic resonator of the present invention thus constructed, the transmission line 3 includes a 50 Ω-line and parallel 100 Ω-lines. Therefore, undesired reflection due to impedance mismatching is prevented, and a high-frequency current transmitted through the 50 Ω-line is distributed substantially equally to the two parallel 100 Ω-lines, so that the intensity of the magnetic field produced by the 100 Ω-line is reduced to approximately a half of that produced by the 50 Ω-line.
In the first embodiment shown in FIG. 1, the recess 4 are formed in the transmission line 3 so as to face the diametrically opposite peripheral portions of the ferrimagnetic thin film 1. However, only one recess 4 may be formed in the grounded end of the transmission line 3 as illustrated in FIG. 3 or, as illustrated in FIG. 4, a pair of high-impedance lines 5, for example, 100 Ω-lines, curving away from each other may be formed at each end of the transmission line 3 to incline the magnetic field Hy along the 100 Ω-lines so that the magnetic field distribution approaches the magnetization distribution in the main mode. In FIGS. 3 and 4, parts corresponding to those previously described with reference to FIG. 1 are denoted by like reference numerals and the description thereof will be omitted
The ferrimagnetic thin film 1 may be formed with the construction as disclosed in U.S. Pat. No. 4,547,754 to enable the ferrimagnetic thin film 1 per se to suppress the spurious magnetostatic mode liable to be generated therein. That is, the generation of magnetization distribution in the spurious resonance mode is suppressed and scarcely effects the main resonance mode by utilizing the fact that the magnetization distribution in the magnetostatic mode in the ferrimagnetic thin film 1 is different between the main resonance mode and the spurious resonance mode. As shown in FIG. 5A by way of example, an annular groove 51 is formed concentrically in the ferrimagnetic thin film 1 so that the high-frequency magnetization of a mode (1, 1) 1 is zero. The annular groove 51 may be either a continuous groove or an intermittent groove.
Another construction of the ferrimagnetic thin film 1 may be formed in which a thin portion 52 is formed in the inner area of the ferrimagnetic thin film 1 as shown in FIG. 5B to suppress excitation of the spurious mode by expanding the flat demagnetizing field in the inner area of the ferrimagnetic thin film 1.
Furthermore, as shown in FIG. 5C, the ferrimagnetic thin film may be provided with a groove 51 and a thin area 52 limited by the groove 51.
Still further, in addition to forming the groove 51 and/or the thin portion 52, or with neither the groove 51 nor the thin portion 52, a necessary magnetization distribution may be obtained through nonmagnetic ion implantation, to suppress the magnetization of the higher mode.
FIGS. 6 to 8 are Smith charts showing measured reflection characteristics of ferromagnetic resonators of a construction shown in FIG. 1 (FIGS. 6 and 7) and of a construction shown in FIG. 3 (FIG. 8) each employing a ferromagnetic thin film 1 of FIG. 5A having the groove 51. FIGS. 6, 7 and 8 show the measured reflection characteristics when resonance frequency f=5 GHz and span Δf=0.46 GHz, when f=10 GHz and Δf=0.6 GHz, and when f=10 GHz and Δf=0.6 GHz, respectively. FIGS. 25 and 26 are also Smith charts showing the measured reflection characteristics of the ferromagnetic resonator described with reference to FIG. 23 when f=5 GHz and Δf=0.4 GHz, and when f=10 GHz and Δf=0.6 GHz, respectively. In the ferromagnetic resonator having the reflection characteristics shown in FIGS. 6 and 7, namely, the ferromagnetic resonator of the construction shown in FIG. 1, and in the ferromagnetic resonator having the reflection characteristics shown in FIG. 8, namely, the ferromagnetic resonator of the construction shown in FIG. 3, a/b=7/3, and a/b=6/4, respectively, where a is the distance between the center of the ferromagnetic thin film 1 and the inner edge of the recess 4, and b is the distance between the inner edge of the recess 4 and the periphery of the ferrimagnetic thin film 1.
As obvious from the comparison between the reflection characteristics of the ferromagnetic resonators of the present invention shown in FIGS. 6 to 8 and those of the ferromagnetic resonator shown in FIGS. 25 and 26 without applying the present invention, the ferromagnetic resonators of the present invention effectively suppress spurious modes where N is two or greater.
FIGS. 9 and 10 show measured transmission characteristics, namely, the variation of insertion loss with frequency, of the ferromagnetic resonator of the present invention shown in FIG. 1. FIGS. 27 and 28 show measured transmission characteristics of the ferromagnetic resonator shown in FIG. 23. In measuring the transmission characteristics, the strip lines each was connected at one end thereof to a signal source and at the other end to a matching load.
As apparent from the comparison of FIGS. 9 and 10 and FIGS. 27 and 28, the ferromagnetic resonator of the present invention is capable of effectively suppressing the spurious mode. The respective external Qs (Qes) of the ferromagnetic resonator (FIG. 23) and the ferromagnetic resonator of the present invention having 100 Ω-lines (FIG. 1) in the second-order spurious mode are 433 and 474 for 1 GHz and 10 GHz, respectively, and 718 and 918 for 1 GHz and 10 GHz, respectively.
FIG. 11 shows the measured variation of the maximum insertion loss in the main mode with a/b representing the length of the 100 Ω-lines, namely, high-impedance portions 5, for the ferromagnetic resonator of FIG. 1. In FIG. 11, curves 101, 102 and 103 are for center frequencies of 1 GHz, 5 GHz and 10 GHz, respectively.
FIG. 12, similarly to FIG. 11, shows the measured variation of the maximum insertion loss in the spurious mode with a/b for the same ferromagnetic resonator. In FIG. 12, curves 111, 112 and 113 are for center frequencies of 1 GHz, 5 GHz and 10 GHz, respectively. As apparent from FIG. 12, the insertion loss in the spurious mode is smallest, namely, the transmission characteristics are improved, when the ratio a/b is on the order of 5/5.
FIGS. 13 and 14 show the variation of insertion loss with frequency for the ferromagnetic resonator of FIG. 1 employing an YIG ferrimagnetic thin film 1 having an annular groove, and for the same ferromagnetic resonator employing an YIG ferrimagnetic thin film 1 without the annular groove, respectively, wherein a/b is pb 5/5. FIGS. 15 and 16 are enlarged illustrations of encircled portions in FIGS. 13 and 14, respectively, showing the insertion loss in the spurious mode. FIGS. 29 and 30 show the variation of insertion loss with frequency in a frequency band having a center frequency on the order of 5 GHz for the ferromagnetic resonator of FIG. 23 employing an YIG ferrimagnetic thin film 1 having an annular groove, and for the ferromagnetic resonator of FIG. 23 employing an YIG ferromagnetic thin film 1 without the annular groove, respectively. FIGS. 31 and 32 are enlarged illustrations of encircled portions in FIGS. 29 and 30, respectively, in the spurious mode.
As is evident from the comparative observation of FIGS. 15, 16, 31 and 32, the ferromagnetic resonator of the present invention is capable of effectively reducing insertion loss in the spurious mode and, as is evident from FIG. 15, the ferrimagnetic thin film provided with the annular groove 51 further improves insertion loss in the spurious mode.
In the foregoing embodiments of the present invention, the pattern of the transmission line 3 is selected form a suitable magnetic field distribution on the YIG ferromagnetic thin film 1. It is also possible to form the suitable magnetic field distribution on the ferrimagnetic thin film 1 by bending the surface of the transmission line 3 as illustrated in FIG. 17 to couple the transmission line 3 with the ferrimagnetic thin film 1 in a desired distribution of the degree of coupling.
In an embodiment shown in FIG. 17, a transmission line 3 is extended along a spacer 7A provided on an insulating substrate 7.
FIGS. 18 and 19 show a ferromagnetic resonator, in another embodiment, according to the present invention. FIG. 18 is a longitudinal sectional view, namely, a sectional view taken along the direction of transmission, and FIG. 19 is a cross-sectional view, namely, a sectional view taken across the direction of transmission. In this embodiment, a protrusion 14 is formed, for example, in the surface of a lower electric conductor 9 facing an YIG ferrimagnetic thin film 1 so that the distance between the lower electric conductor 9 and the ferrimagnetic thin film 1 vary in a desired distribution over the ferrimagnetic thin film 1 to selectively form a desired magnetic distribution on the ferrimagnetic thin film 1. In FIGS. 17, 18 and 19, parts similar to those previously described with reference to FIG. 1 are denoted by the same reference numeral and the description thereof is omitted.
FIGS. 20 to 22 illustrates a ferromagnetic resonator according to the present invention as applied to a variable-frequency microwave filter, in which FIGS. 20, 21 and 22 are a sectional view, a plan view and an exploded perspective view, respectively, of the variable-frequency microwave filter.
Referring to FIGS. 20 to 22, a first YIG ferrimagnetic thin film 1A and a second YIG ferromagnetic thin film 1B are formed over a GGG nonmagnetic substrate 6 with a predetermined space therebetween. A third YIG ferromagnetic thin film 1C is formed over the GGG nonmagnetic substrate 6 between the first and second YIG ferromagnetic thin films 1A and 1B to magnetically couple the first and second YIG ferrimagnetic thin films 1A and 1B. A first transmission line 3A, namely, an input microstrip line, and a second transmission line 3B, namely, an output microstrip line, are formed on the other side of the GGG nonmagnetic substrate 6 so as to be coupled with the first and second YIG ferrimagnetic thin films 1A and 1B, respectively. A central grounding pattern 13 is formed on the surface carrying the input transmission line 3A and the output transmission line 3B of the GGG nonmagnetic substrate 6 across an area extending opposite to the third YIG ferromagnetic thin film 1C so as to interconnect one end of the first transmission line 3A and one end of the second transmission line 3B opposite the end of the first transmission line 3A connected to the grounding pattern 13. The nonmagnetic substrate 6 carrying the ferrimagnetic thin films 1A, 1B and 1C, the transmission lines 3A and 3B, and the grounding pattern 13 is held between an upper electric conductor 8 and a lower electric conductor 9 with the grounding pattern 13 and the respective grounded ends of the transmission lines 3A and 3B in electrical contact with the upper electric conductor 8. The nonmagnetic substrate 6 carrying the ferrimagnetic thin films 1A, 1B and 1C, the transmission lines 3A and 3B and the grounding pattern 13, the upper electric conductor 8 and the lower electric conductor thus assembled form a microwave filter unit. The microwave filter unit is disposed in the magnetic gap formed between the respective magnetic poles 14a 1 and 14b 1 of a pair of bell-shaped magnetic cores 14a and 14b. At least either the magnetic core 14a or 14b is provided with a coil 15 on the central magnetic pole thereof. DC current supplied to the coil 15 is regulated to vary the center frequency of resonance for variable-frequency control.
The microwave filter unit may be formed in any one of the constructions shown in FIGS. 1, 3, 4, 17, 18 and 19 to provide desired magnetic field distributions on the input ferrimagnetic thin film 1A and the output ferrimagnetic thin film 1B to make the ferrimagnetic thin films 1A and 1B suppress the spurious mode.
As described hereinbefore, according to the present invention, a magnetic field distribution corresponding to the magnetization distribution in the main mode is formed on the ferrimagnetic thin film 1 serving as a resonance element to reduce the degree of coupling of the ferrimagnetic thin film 1 with the transmission line 3 in the spurious mode, so that the spurious resonance can effectively be suppressed. Furthermore, the present invention suppressed the spurious resonance through simple structural modification and disposition of the transmission line without requiring any additional element.
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A ferromagnetic resonator is disclosed, in which perpendicular ferrimagnetic resonance of thin film YIG is utilized. The resonator comprises a ferrimagnetic YIG thin film and a microstrip line coupled to the YIG thin film operative in a bias magnetic field applied perpendicular to a major surface of the YIG thin film. The YIG thin film disk has a magnetization distribution of magnetostatic mode, and the microstrip line is designed to generate a high-frequency magnetic field distribution similar to the magnetization distribution of the uniform mode (1, 1) 1 . In such arrangement, coupling between the high-frequency magnetic field and magnetization of high sprious mode is reduced.
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FIELD OF THE INVENTION
The present invention relates to a modular projector lift and, in particular, to a projector lift system that can be expanded or contracted to accommodate projectors of various sizes.
BACKGROUND OF THE INVENTION
Audiovisual equipment, such as televisions, projectors, and computer monitors are in widespread usage for home entertainment and business applications, as well as theaters, auditoriums, and presentation rooms. In order to enhance the aesthetics of these facilities, it is becoming increasingly common to store audiovisual equipment in ceilings, cabinets, walls, and floors. For example, audiovisual equipment can be raised and lowered through the center of a conference table. Typically, a false surface or panel is affixed to the projector lift system to conceal the audiovisual equipment under the table when not in use.
Prior lift systems are typically designed to fit a particular size piece of audiovisual equipment. With the explosive growth in the variety and sizes of audiovisual equipment, manufacturers of lift systems typically build different systems to accommodate different size audiovisual equipment. Additionally, some prior lift systems lack the accuracy and repeatability to precisely position a false surface or panel for effectively concealing the audiovisual equipment. Prior lift systems generally lack a safety feature to prevent the user from being injured if they inadvertently place their fingers at the sheer point between the moving audiovisual equipment and a storage compartment. Finally, as the size of audiovisual equipment continues to increase, with a corresponding increases in weight, many prior lift systems lack the braking capacity to safely retain the audiovisual equipment in an extended or exposed position for a prolonged period of time.
SUMMARY OF THE INVENTION
The present invention relates to a modular projector lift that can be expanded or contracted to accommodate projector devices of various sizes. The modular projector lift can be accurately and repeatably positioned at desired locations. The projector lift system may also include a brake system sufficient to retain large projection devices in an extended position.
The modular projector lift system moves a projection device along a path between an extended position and a retracted position. The drive assembly is expandable along a first axis. The movable support is mechanically engageable with the drive assembly at a plurality of positions along the first axis. The movable support moves the projection device between the extended position and the retracted position.
The present modular projector lift system may be configured to move a projection device in a variety of orientations. The retracted position may be either above or below the extended position. Alternatively, the path of movement may be horizontal.
The drive assembly is preferably a motor having a telescoping drive shaft oriented parallel to the first axis. The drive assembly utilizes a drive chain coupled to the movable support. A false surface may optionally be connected to the modular projector lift for concealing the modular projector lift system when in the retracted position. In one embodiment, the movable support is a slide bracket movable in an extrusion along the path. Alternatively, the movable support may be constructed as a telescoping structure movable along the path. The telescoping structure may include two or more telescoping extrusion members. The modular projector lift preferably includes a pair of movable supports having an adjustable separation along the first axis.
The drive assembly preferably includes a brake mechanism for maintaining the position of the movable support relative to the drive assembly. The brake mechanism is activated when electric power to the drive assembly is reversed. In one embodiment, the brake mechanism includes a plurality of rotating brake plates connected to a drive shaft. The drive shaft couples the drive assembly to the movable support. A plurality of static brake plates are connected to the drive housing compressively engaged with the rotating brake plates, respectively. The brake mechanism provides variable levels of compressive engagement between the rotating and the static brake plates.
The drive assembly may also include an adjustable limit switch for adjusting a location of the retracted position along the path. The adjustable limit switch may adjust the location of the extended and the retracted positions along the path.
At least one emergency pressure switch is provided for reversing movement of the movable support relative to the drive assembly. The pressure switch is preferably located at the shear point along the perimeter of the platform or the projection device for reversing movement of the projection device along the path.
In an alternate embodiment, the modular projector lift system includes a drive assembly expandable along a first axis. The drive assembly includes a telescoping drive shaft oriented parallel to the first axis. A pair of movable support are mechanically coupled to the drive shaft for moving the projection device between the extended position and the retracted position. The separation between pair of movable supports is adjustable along the first axis. A brake mechanism is provided for maintaining the position of the movable support relative to the drive assembly. The brake mechanism includes a plurality of rotating brake plates connected to the drive shaft and a plurality of static brake plates connected to the drive assembly compressively engaged with the rotating brake plates.
In yet another embodiment, the modular projector lift system has a drive assembly expandable along a first axis and a brake mechanism for maintaining the position of the movable supports relative to the drive assembly. A pair of movable supports are mechanically coupled to the drive shaft for moving the projection device between the extended position and the retracted position. The pair of movable supports have an adjustable separation along the first axis. Adjustable limit switches are provided for adjusting a location of the retracted and the extended positions along the path.
As used herein Projection Device refers to a television, computer monitor, video projector, or a variety of other audiovisual projector systems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a modular projector lift system extending below a surface;
FIG. 2 is a perspective view of a modular projector lift system extending above a surface;
FIG. 3 is a perspective view of a modular projector lift system extending horizontally beyond a surface;
FIG. 4 is a top view of an expandable drive assembly for use with the present modular projector lift system;
FIG. 5 is a side view of a movable support for use with the present modular projector lift system;
FIG. 5A is an end view of the movable support of FIG. 5;
FIG. 5B is a side view of an alternate movable support containing a plurality of telescoping extrusion members for use with the present modular projector lift system;
FIG. 6 is a top view of a brake assembly for use with the present modular lift system; and
FIG. 7 is a top view of a travel limit mechanism for use with the present modular projector lift system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1-3 show various orientations of the modular projector lift system 20 of the present invention. FIG. 1 is a perspective view of a modular projector lift system 20 for moving a projector device 22 along a path H between an extended position 25 and a retracted position in recess 41. The movable support 28 is engaged with the drive housing 26 by first portion 70. The movable support 30 is engaged with the drive housing 26 by second portion 72. A mounting bracket 36 is rigidly attached to the distal ends of first telescoping extrusions 32. The first and second portions 70, 72 are telescopically engaged with the drive housing 26, as will be discussed below. It will be understood that attachment of the first and second portions 70, 72 to the drive housing 26 may be achieved by a variety of means, such as the slotted openings 70A and 72A.
Slide bracket 31 at the end of second telescoping extrusions 34 and rides along an inside surface of the first extrusions 32 with rollers 185 (see also FIGS. 5 and 5A). The drive housing 26 is mounted to a surface 40 by a mounting bracket 42. A drive assembly 50 (see FIG. 4) contained within the drive housing 26 serves to raise and lower the slide bracket 31 in the first extrusions 32 so that the projector device 22 can be positioned either above surface 52 in a recess 41, or below the surface 52. The surface 52 is typically a ceiling or inner surface of a cabinet structure.
FIG. 2 is a perspective view of an alternate configuration of the present modular projector lift system 20 in which the projector device 22 can be positioned either above or below surface 54. A projector platform 24 is connected to the slide brackets 31 for supporting the projector device 22. The surface 54 may be a floor, the top of a cabinet or table. The mounting bracket 42 retains the drive housing 26 to a surface 60 below the surface 54. The bracket 36 may be used to attach the movable supports 28, 30 to the inside of a cabinet or other structure. A false surface 62 is preferably provided on the top of the projector device 22. The false surface 62 is preferably flush with the surface 54 when the projector device 22 is positioned in recess 64.
FIG. 3 is a perspective view of an alternate configuration of the present modular projector lift 20 in which the projector device 22 can be moved horizontally along a path H between an extended position and a retracted position. The second extrusion 34 is preferably attached to the slide bracket 31. The second extrusion 34 serves to support the projection device 22 when in the extended position. Additionally, by attaching the projection device 22 to the distal ends of the extrusions 34, the effective length of the path H can be extended.
Surface 67 is preferably a wall or the side of a cabinet. The mounting bracket 42 retains the drive housing 26 to a surface 68 inside recess 69. A false surface 66 is preferably provided on the side of the projector device 22 so that it will be flush with the surface 67 when the projector device 22 is positioned in recess 69.
A pressure sensitive switch 21, such as a ribbon switch available from Tapeswitch Corporation of Farmingdale, N.Y., is preferably positioned around a perimeter 23 of the projector device 22, or alternatively around the perimeter of the platform 24 (see FIG. 2). In the event that an object or fingers of the user are accidentally located along the shear point between the modular projector lift system 20 and one of the surfaces 52, 67, the switch 21 reverses the movement of the projection device 22.
FIG. 4 is a top view of the drive housing 26 containing a drive assembly 50. The first and second portions 70, 72 (see also FIGS. 1-3) may be expanded or contracted along an axis A to accommodate projector devices of various sizes. The axis A is preferably parallel to the axis of drive shaft 86. In one embodiment, the first and second portions 70, 72 can be expanded to accommodate projector devices having a width of between 0.69 and 0.94 meters.
The drive assembly 50 is preferably mounted to a drive assembly plate 76 contained within the drive housing 26. The drive assembly 50 includes a pair of motors 78, 80, each including a direct drive transmission system 82, 84, respectively, for engaging with the drive shaft 86. A motor with a suitable internal braking system is available from Merkle-Korff Industries, Inc. of Des Plaines, Ill., under model number 189400. A timing chain 90 couples the drive shaft 86 to a limit switch mechanism 92 via pulleys 88, 94. The limit switch mechanism 92 includes a pair of thumb screws 96, 98 accessible from the outside of the drive housing 26 for adjusting the limit switch mechanism 92, as will be discussed in detail below. A control circuit 93 is preferably located below the limit switch mechanism 92. Plug 97 connects power cables and control cables (not shown) for operating the present modular projector lift 20. Alternatively, a detector 99 may be provided for receiving infrared or RF signals for controlling the modular projector lift 20.
First telescoping drive shaft 100 is engaged with the drive shaft 86 via a coupling 102. Correspondingly, a second telescoping drive shaft 104 is coupled with the drive shaft 86 by a coupling 106. As best seen in FIG. 5A, the first telescoping drive shaft 100 telescopically engages with a corresponding drive shaft 103 in the first portion 70 of the movable support 28. Consequently, the movable support 28 can be extended or retracted along a drive axis A while maintaining a mechanical engagement between the drive shafts 100, 103. The second telescoping drive shaft 104 telescopically engages with a corresponding drive shaft 105 in the second portion 72 of the movable support 30. The second telescoping drive shaft 104 may also be extended or contracted along the axis A in a manner corresponding with the movement of the second portion 72.
Rotation of the drive shaft 86 is controlled by brake mechanisms internal to the motors 78, 80 (not shown) and the brake assembly 110. As best illustrated in FIG. 6, the brake assembly 110 includes a series of inner brake plates 112 mounted to the drive shaft 86. Each of the inner brake plates 112 is interposed between outer brake plates 114 which are not engaged with the drive shaft 86. A rocker arm 116 mounted at pivot point 120 provides a compressive force on brake stack assembly 118 via roller 122. A solenoid 124 is provided for moving the rocker arm 116 to a disengaged position 126 so that roller 122 moves along the axis A, away from the brake stack assembly 118. When the solenoid 124 is disengaged, biasing mechanism 127 moves the rocker arm 116 to an engaged position 128 such that the roller 122 provides a compressive force on the brake stack assembly 118. The high surface area of engagement between the inner brake plates 112 and the outer brake plates 114 provide significant braking force for the drive assembly 50.
The brake stack assembly 118 preferably includes 16 inner brake plates 112 and 15 outer brake plates 114, to provide a total surface area of engagement of approximately 387.1 cm 2 (60 inches 2 ). When subjected to a compressive force of approximately 71.2 Newtons (16 pounds), the brake assembly 110 provides a braking torque of approximately 21.22 Newton.meters (188 inch.lbs). The inner and outer brake plates 112, 114 are preferably constructed of steel or a variety of brake materials. The plates 112, 114 may be anodized, plated, such as with chrome, or painted with an electrodeposition process. It will be understood that the number of plates 112, 114 may vary with the desired brake force and plates of different compositions may be alternated.
Turning back to FIG. 4, the solenoid 124 is mounted to the drive assembly mounting plate 76 by a bracket 140 with a pair of tensioning slots 142 so that the location of the solenoid 124 relative to the rocker arm 116 can be adjusted for optimum performance. A pair of brake assembly tension adjustment slots 146 are provided for adjusting the position of the brake assembly 100 relative to the rocker arm 116, so that the static load on the brake stack assembly 118 can be adjusted when the rocker arm 116 is in the engaged position 128.
FIGS. 5 and 5A illustrate the movable supports 28, 30 engagable with the drive assembly 50 of the present modular projector lift system 20. The movable supports 28, 30 are rigidly connected to the first or second portions 70, 72. Sprocket 180 is mechanically engaged with a drive shafts 103, 105 that telescopically engage with one of the telescoping drive shafts 100, 104. A sprocket 184 is rotatably mounted on the distal end of the extrusion 32 proximate the mounting bracket 36. Drive chain 182 extends around sprockets 180, 184. The drive chain 182 is fixedly attached to the slide bracket 31 at bracket 186. Rotation of the sprocket 180 causes the slide bracket 31 to move along the path H in the extrusion 32 between an extended position and a retracted position past surfaces 52, 54, 67. The slide bracket 31 preferably includes a series of rollers 185 to insure smooth engagement with the extrusion 32. In one embodiment, the movable supports 28, 30 provide up to 0.94 meters of travel with a lifting capacity in excess of 100 kgs. It will be understood by those of skill in the art that the travel and lifting capacity may be varied without departing from the scope of the present invention.
FIG. 5B illustrates an alternate embodiment in which the movable supports 201 include three or more telescoping rails 190, 192, 194 engaged with the drive assembly 50 of the present modular projector lift system 20. A first telescoping rail 190 is rigidly connected to the first or second portions 70, 72. Sprocket 196 is mechanically engaged with a drive shafts 103, 105 that telescopically engages with one of the telescoping drive shafts 100, 104, as discussed above. A pair of keyed sprockets 198, 200 are rotatably mounted on the second telescoping rail 192 so that they turn together. A drive chain 202 extends around sprockets 196, 198. The drive chain is fixedly attached to the second telescoping rail 192 at bracket 204. A second drive chain 206 extends around the sprocket 200 and a second rotating sprocket (not shown) on a distal end of the third telescoping rail 194. The second drive chain 206 is fixedly attached to the third telescoping rail 194 by a bracket 208. Rotation of the sprocket 196 causes simultaneous rotation of the sprockets 198, 200, causing synchronous movement of the second and third telescoping rails 192, 194 between an extended position and a retracted position past surfaces 52, 54, 67. It will be understood that the number of telescoping rails may vary without departing from the scope of the present invention.
FIG. 7 is a top view of the limit switch mechanism 92. As the drive shaft 86 rotates (see FIG. 4), the timing chain 90 causes a coupling nut 162 to move along a threaded lead screw 160. The coupling nut 162 includes a plate 164 for activating limit switches 166, 168. The thumb screw 96 is connected to an adjustment screw 170 for moving an upper limit slider 172 along a support shaft 174. As the coupling nut 162 moves along the threaded shaft 160 due to rotation of the drive shaft 86, the plate 164 eventually engages the limit switch 166. The limit switch deactivates the motor and prevents further movement of the projector platform 24 relative to the drive housing 26. Similarly, thumb screw 98 is connected to adjustment screw 176. Rotation of the thumb screw 98 causes lower limit slider 178 to move along support shaft 174. Rotation of the drive shaft 86 in the opposite direction causes the coupling nut 162 to move in the alternate direction until the plate 164 engages the limit switch 168. The user can limit the movement of the projector platform 24 in either direction by positioning the upper and lower limit sliders 172, 178 at an appropriate location along the length limit switch mechanism 92.
The present invention has now been described with reference to several embodiments described herein. It will be apparent to those skilled in the art that many changes can be made in the embodiments without departing from the scope of the invention. Thus, the scope of the present invention should not be limited to the structures described herein, but only to structures described by the language of the claims and the equivalents to those structures.
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A modular projector lift system for moving a projection device along a path between an extended position and a retracted position. The modular projector lift system includes a drive assembly expandable along a first axis. At least one movable support is mechanically engagable with the drive assembly at a plurality of positions along the first axis. The movable support moves the projection device between the extended position and the retracted position. A brake mechanism is optionally included for retaining the projection device at a particular location. The brake mechanism includes a plurality of rotating brake plates connected to the drive shaft of the drive assembly and a plurality of static brake plates connected to the drive assembly compressively engaged with the rotating brake plates. Adjustable limit switches are optionally provided for adjusting a location of the retracted and the extended positions along the path.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to novel, potent anticonvulsants, antiepileptics, analgesics and cognition enhancers achieving their action through the antagonism of specific excitatory amino acid (EAA) neurotransmitter receptors. In particular, the invention is directed to ω-[2-(phosphonoalkylenyl)phenyl]-2-aminoalkanoic acids, their pharmaceutically acceptable salts and derivatives, and to the methods of synthesizing the same.
2. Description of the Prior Art
While L-glutamate and L-aspartate were initially thought merely to participate in brain metabolism, sufficient molecular pharmacological, biochemical and electrophysiological evidence now exists to suggest that these amino acids are neuroexcitatory transmitters [D. R. Curtis, A. W. Duggar, D. Felix, G. A. R. Johnston, A. K. Tebecis and J. C. Watkins. Brain Res. 41:283-301 (1972)].
For many years following the initial characterization of the neuro-excitotoxic actions of amino acis, it was tacitly assumed that all compounds of this type (agonists and antagonists) acted upon the same receptor. The discovery of relatively selective antagonists of different actions of EAA or of actions of different EAA compounds, has changed this perception, and it is now accepted that multiple recognition sites for EAA are present in the vertebrate central nervous system [J. C. Watkins and R. H. Evans. Ann. Rev. Pharmacol. Toxicol. 21:165-204 (1981)]. Defined by prototypical agonists or antagonists, these include:
1. receptors activated by L-Glutamate (Glu) and the conformationally restricted Glu analog, quisqualic acid (Quis), and antagonized selectively by glutamic acid diethylester,
2. receptors responsive to the synthetic analogue of L-aspartate (Asp), N-methyl-D-aspartate (NMDA), the isoxazole neurotoxin, ibotenic acid (Ibo), the pyridinedicarboxylic acid neurotoxin, quinolinic acid (Quin) and, probably, to Asp itself. These receptors are antagonized by D(-)-2-amino-5-phosphonopentanoic acid (AP5), D(-)-2-amino-7-phosphonoheptanoic acid (AP7), and the divalent cation, Mg++,
3. receptors activated by the pyrrolidine neuroexcitotoxin, kainic acid (KA), for which no specific antagonists have yet been identified and,
4. receptors antagonized by L(+)-2-amino-4-phosphonobutyric acid (LAP4). Originally identified as an EAA antagonist by electrophysiological means, LAP4 inhibits the response at the lateral perforant pathway synapses of the hippocampus to an unidentified endogenous excitatory substance. The possibility that Glu is this neurotransmitter is minimal and recent evidence suggests that the N-blocked dipeptide, N-acetylaspartyl-L-glutamate may function in this capacity [J. M. H. ff-French-mullen, K. J. Koller, R. Zaczek, Li Hori, J. T. Coyle and D. O. Carpenter. Proc. Nat. Acad. Sci. USA 82, 3897-4001 (1985)].
EAA's, possibly acting through one or more of these receptors, have been implicated in the etiology of various pathological conditions affecting the CNS. Thus, KA [K. Biziere, J. T. Slevin, R. Zaczek, J. C. Collins and J. T. Coyle. In: Advances in Pharmacology and Therapeutics (H. Yoshida, Y. Hagihara and S. Ebashi, eds) Pergamon, New York. pp. 271-276 (1982)], NMDA [R. Zaczek, J. Collins and J. T. Coyle. Neurosci. Letts 24:181-186 (1981)] and the endogenous excitatory amino acid Quin [R. Schwarcz, W. O. Whetsell and R. M. Mango. Science 219:316-318 (1983)] have been used to produce in animal models a syndrome analogous to human epilepsy and other convulsive disorders, and the anatomical and neurochemical lesions and deficiencies produced by such chemicals in animals with these compounds are similar to the characteristics seen postmortem in the brains of patient's dying of Huntington's disease [J. Coyle, and R. Schwarcz. Nature 263:244-246 (1976)] and epilepsy. Kainate administration can produce a limbic structure lesion that mimicks Ammon's Horn Sclerosis, an abnormality frequently found in temporal lobe epilepsy. Research on this model of temporal lobe epilepsy has suggested that endogenous EAA's may play a role in this disorder, that is particularly resistant to existing antiepileptics [J. V. Nadler, B. W. Perry, C. W. Cotman. Nature 271:676-677 (1978)]. In addition to Huntington's disease and epilepsy, it has been suggested that EAA's may contribute to Alzheimer's disease [A. C. Foster, J. F. Collins and R. Schwarcz. Neuropharmac. 22:1331-1341 (1983)], E. Roberts. In: Strategies for the development of an Effective Treatment for Senile Dementia (E. Crook and L. Gershon, eds.) Mark Power Assoc., New Camarin, Conn. pp. 247-230 (1981)], the neuronal death following stroke and other factors leading to cerebral ischemia, [R. P Simon, J. H. Swan, T. Griffiths and B. S. Meldrum, Science, 226, 850-852, (1984); S. Rothman. J. Neuroscience 4:1884-1891 (1984)] and hereditary olivopontocerebellar atrophy [J. T. Coyle, TINS 5:287-288 (1982)].
Because of the conceptual link between EAA activity at specific brain receptors in vitro and in vivo, excitotoxic lesions caused by EAA in animals, and the pathogeneis of the above neurodegenerative diseases, it is logical to explore pharmacologic means to antagonize endogenous excitatory and excitotoxic neurotransmitters. The development of antagonists of exogenous excitotoxins such as KA is also logical, since there is presumably and yet undiscovered specific endogenous substance that acts at brain KA receptors. The advent of potent and selective antagonists of EAA's exemplified by α-amino-ω-phosphonoalkylenylcarboxylic acids (the most potent and selective being D(-)-2-amino-7-phosphonoheptanoic acid, D(-)AP7 has provided a point of departure for the pharmacologic intervention of EAA action at their receptors.
Besides interfering with the neurotoxic and convulsive actions of NMDA, the exogenous excitotoxin, IBO, and the endogenous excitotoxin Quin (but not KA) [A. C. Foster and G. E. Fagg. Brain Res. Rev. 7:103-184 (1984); A. C. Foster, J. F. Collins and R. Schwarcz. Neuropharmac. 22:1331-1341 (1983); R. Schwarcz, J. F. Collins and D. A. Parks, Neurosci. Letts 33:85-90 (1982)], AP7 (i.c.v. and i.v.) protects against audiogenically-induced seizures in genetically susceptible mice [M. J. Croucher, J. F. Collins and B. S. Meldrum. Science 216:899-901 (1982)]. I.v. AP7 suppresses photically-induced myoclonus in the baboon [B. S. Meldrum. M. J. Croucher, G. Badman and J. F. Collins, Neurosi. Letts 39:101-104 (1983)], increases threshold current for electroshock induced seizures of mice and prevents chemically induced seizures in rodents [S. J. Czuczwar and G. Meldrum. Eur. J. Pharmac. 83:335-338 (1982)]. Very recently, AP7 (intrahippocampally) has been reported to markedly reduce or eliminate ischemic brain damage in the rodent carotid artery occlusion model of stroke [R. P. Simon, J. H. Swan, T. Griffiths and B. S. Meldrum. Science 226:850-852 (1984)], and another, less potent, EAA antagonist δ-D-glutamyl glycine, has been shown to protect cultured at hippocampal neurones from degeneration under conditions of oxygen depletion while blocking the toxicity of exogenously applied Glu and Asp [S. Rothman. J. Neuroscience 4:1884-1891 (1984)]. Recently, kainate and quisqualate receptor antagonists have also been shown to posses anticonvulsant activity [M. J. Croucher, B. S. Meldrum, A. W. Jones and J. C. Watkins. Brain Res. 377:111-114 (1984)]. Finally, and significantly, several lines of circumstantial evidence link excitatory amino acids, especially glutamate, with the onset of age-associated neurodegenerative diseases, including Alzheimer's disease [J. T. Greenamyre, J. B. Penney, A. B. Young, C. D'Amato, S. P. Hicks, I. Schoulson, Science 227:1496-1498 (1985)], and with tardive dyskinesia [J. W. Olney. In: Excitotoxins (K. Fuxe, R. Roberts, and R. Schwarcz, eds)].
SUMMARY OF THE INVENTION
The present invention provides a potent, selective excitatory amino acid neutrotransmitter receptor antagonist having the general formula: ##STR2## wherein R 1 and R 2 are the same or different and are selected from the group consisting of hydrogen, lower alkyl, halogen, --CH═CH--CH═CH--, amino, nitro, trifluoromethyl or cyano; n and m=0, 1, 2 or 3; and the pharmaceutically acceptable salts and derivatives thereof.
DETAILED DESCRIPTION OF THE INVENTION
The structure and formulation of the novel compounds of the invention was the result of the extensive research investigation into the antagonism of heterogenic excitatory amino acid neurotransmitter receptors.
Defined by prototypical agonists or antagonists, these include:
1. receptors activated by L-Glutamate (Glu) and the conformationally restricted Glu analog, quisqualic acid (Quis), and antagonized selectively by glutamic acid diethylester,
2. receptors responsive to the synthetic analogues of L-aspartate (Asp), N-methyl-D-aspartate (NMDA), the isoxazole neurotoxin, ibotenic acid (Ibo), the pyridinedicarboxylic acid neurotoxin, quinolinic acid (Quin) and, probably, to Asp itself. These receptors are antagonized by D(-)-2-amino-5-phosphonopentanoic acid (AP5), D(-)-2-amino-7-phosphonoheptanoic acid (AP7), and the divalent cation, Mg++,
3. receptors activated by the pyrrolidine neuroexcitotoxin, kainic acid (KA), for which no specific antagonists have yet been identified and,
4. receptors antagonized by L(+)-2-amino-4-phosphonobutyric acid (LAP4). Originally identified as an EAA antagonist by electrophysiological means, LAP4 inhibits the response at the lateral perforant pathway synapses of the hippocampus to an unidentified endogenous excitatory substance. The possibility that Glu is this neurotransmitter is minimal and recent evidence suggests that the N-blocked dipeptide, N-acetylaspartyl-1-glutamate may function in this capacity [J. M. H. ff-French-mullen, K. J. Koller, R. Zaczek, Li Hori, J. T. Coyle and D. O. Carpenter, Proc. Nat. Acad. Sci. (USA) 82, 3897-4001 (1985)].
The structure of novel compounds provides potent antagonists having greater affinity toward one of the receptors or no affinity to some of them rendering the compound selective. This would therefore permit one to selectively antagonize one EAA receptor in the tissue also containing other EAA receptors. As a result of the greater affinity and selectivity of the present invention fewer side effects are exhibited by the novel compounds.
The high affinity and selectivity of such compounds e.g.: 3-[2-(2-phosphonoethyl)phenyl]-2-aminopropanoic acid or 3-[2-(2-phosphonomethyl)phenyl]-2-aminopropanoic acid, has been demonstrated in receptor binding studies and in mice by their ability to provide protection in pentylenetetrazol (PTZ) induced seizures.
The novel compounds of the invention can be readily prepared by the following synthetics routes: ##STR3##
In route 1, leading to compounds of examples I and IV, the reaction of isochroman with a solution of hydrobromic and acetic acids in a sealed tube gives the required intermediate o-(2-bromoethyl)benzyl bromide in high yield (Anderson, E. L.; Holliman, F. G. J. Chem. Soc., 1950, 1037). The reaction of this compound with triethylphosphite gives the compound of example I in 70% yield. The compound of example II, ethyl 4-[2-(diethylphosphono-methyl)-phenyl]-2-acetamido-2-carboethoxy-butanoate was prepared by reacting the bromophosphonate described in example I with the sodium salt of diethylacetamidomalonate. Hydrolysis in 6N HCl gives the compound of example III. Alternatively, reacting the intermediate o-(2-bromoethyl)benzyl bromide with the sodium salt of diethyl acetamidomalonate gives the compound of example IV. Reaction of this compound with triethylphosphite gives the compound of example V in 75% yield. Hydrolysis in 6N HCl gives the compound of example VI. ##STR4## In route 2, the commercially available α,α'-dibromo-o-xylene reacts with triethylphosphite giving the compound of example VII. Reaction of this intermediate with the sodium salt of diethyl acetamidomalonate yields the compound of example VIII. Hydrolysis in 6N HCl gives the compound of example IX. ##STR5## In route 3, it is necessary to synthesize the required intermediate o-(3-bromopropyl)benzyl bromide [Rieche, A.; Gross, H. Chem. Ber., 1962, 91]. Chloromethylation of 3-phenylpropanol gives chloromethyl 3-phenylpropyl ether in high yield. Friedel-Crafts cyclization with AlCl 3 in CS 2 gives 2-benzoxepine. Reaction of this compound with a solution of hydrobromic acid-acetic acid in a sealed tube yields the required common intermediate o-(3-bromopropyl)benzyl bromide. Reaction of this compound with the sodium salt of diethyl acetamidomalonate yields the compound of example X. Reaction of this compound with triethylphosphite gives the phosphonomalonate compound of example XI. Hydrolysis in 6N HCl gives the compound of example XII. Alternatively, reacting the intermediate o-(3-bromopropyl)benzyl bromide with triethylphosphite gives the compound of example XIII. Reacting this compound with the sodium salt of diethyl acetamidomalonate gives the compound of example XIV. Hydrolysis in 6N HCl gives the compound of example XV.
The preparation of compounds for administration in pharmaceutical preparations may be in a variety of well known methods known to those skilled in the art of pharmacy. More specifically the novel compounds may be formulated as an acid salt, i.e., HCl salt, sulfate, phosphate, nitrate, methanesulfonate, tartrate or a base salt and other pharmaceutically acceptable salts and compositions.
In parenteral administration of the novel compounds and compositions of the invention the compounds may be presented in aqueous injection solutions which may contain antioxidants, buffers, bacteriostats, etc. Extemporaneous injection solutions may be prepared from sterile pills, granules or tablets which may contain diluents, dispersing and surface active agents, binders and lubricants.
In the case of oral administration, fine powders or granules of the compound may be formulated with diluents and dispersing and surface active agents, and may be prepared in a draft in water or in a syrup, in capsules or cachets in the dry state or in a non-aqueous suspension, when a suspending agent may be included. The compounds may also be administered in tablet form along with optional binders and lubricants, or in a suspension in water or a syrup or an oil or in a water/oil emulsion and may include flavoring, preserving, suspending, thickening and emulsifying agents. The granules or tablets for oral administration may be coated and other pharmaceutically acceptable agents and formulations may be utilized as known to those skilled in the art.
The following examples are illustrative of compounds of the invention but are not to be construed as limiting the invention thereto.
EXAMPLES
PREPARATION EXAMPLES
EXAMPLE I
Diethyl 2-(2-Bromoethyl)benzylphosphonate
In a round bottom flask equipped for distillation, 15.0 g (54 mmol) of 2-(2-bromoethyl)benzyl bromide and 9.0 g (54 mmol) of triethylphosphite were heated on an oil bath with stirring at 90°-100° C. When ethyl bromide ceased distilling off (1 h) the remaining volatile by-products and triethylphosphite were removed from the mixture by distillation under vacuum. The viscous oil which remained was chromatographed on a column of silica gel with hexane-ethyl acetate (1:1) as eluant. The combined fractions were concentrated under reduced pressure to yield 12.5 g (70%) of the product as a yellow oil. IR(neat): 2987, 1249, 1170, 1064, 964, 802 cm -1 . 1 H NMR(CDCl 3 ) δ 1.2 (t, 6H); 3.0-4.35 (m, 10H); 7.2 (s, 4H).
EXAMPLE II
Ethyl 4-[2-(diethylphosphonomethyl)phenyl]-2-acetamido-2-carboethoxybutanoate
To 1.03 g (44.8 mmol) of sodium in 50 mL of dry ethanol was added 9.72 g (44.8 mmol) of solid diethyl acetamidomalonate portionwise. This solution was stirred at reflux under nitrogen for 2 h. After cooling to room temperature the solvent was removed under reduced pressure yielding a tan solid. This solid was dried under vacuum about 2 h. The sodium salt of diethyl acetamidomalonate was then suspended in 50 mL of dry toluene and 15.0 g (44.8 mmol) of diethyl 2-(2-bromoethyl)benzylphosphonate in 25 mL of toluene was added dropwise. This solution was stirred at reflux under nitrogen for 36 h. After cooling the solution to room temperature the solid precipitate was removed by filtration and washed with 20 mL of toluene. The combined toluene solutions were concentrated under reduced pressure to yield a viscous oil. This oil was chromatographed on a column of silica gel with ethyl acetate as eluant. The combined fractions were concentrated under pressure to give 7.2 g (34%) of the product as a clear viscous oil. IR(neat): 1745, 1676 (C═O) cm -1 . 1 H NMR(CDCl 3 ) δ 1.0-6 (m, 12H); 1.8-3.2 (complex m, 9H); 3.7-4.6 (m, 8H); 6.8-7.4 (m, 5). Anal. Calcd. for C 22 H 34 NO 8 P0.5H 2 O: C, 54.99; H, 7.34; N, 2.92. Found: C, 54.75; H, 7.37; N, 2.97.
EXAMPLE III
4-[2-Phosphonomethylphenyl]-2-aminobutanoic acid
A solution of 2.5 g (5.3 mmol) of ethyl 4-[2-(diethylphosphonomethyl)-phenyl]-2-acetamido-2-carboethoxybutanoate in 50 mL of 6N HCl was stirred at vigorous reflux for 12 h. After cooling to room temperature the reaction mixture was concentrated at reduced pressure yielding an oil. This oil was washed with three 50 mL portions of water then dissolved in 95% ethanol and a slight excess of propylene oxide added. The precipitated acid was collected by filtration and recrystallized from dilute ethanol yielding 1.26 g (77%) of the product as a white solid: mp 247°-249° C. IR(KBr): 1725, 1620 cm -1 ; 1 H NMR (D 2 O) δ 2.0-3.4 (6H unresolved), 3.9-4.3 (m, 1H), 7.4 (s, 4H); Anal. Calcd. for C 11 H 16 NO 5 P0.5H 2 O: Calcd: C, 46.62; H, 6.05; N, 4.94. Found: C, 46.73; H, 6.04; N, 4.79.
EXAMPLE IV
Ethyl 3-[2-(2-bromoethyl)phenyl]-2-acetamido-2-carboethoxypropanoate
To a solution of 0.41 g (18 mmol) Na in 100 mL of dry ethanol was added portionwise 3.9 g (18 mmol) of solid diethylacetamidomalonate. This mixture was stirred at reflux under nitrogen for 2 h then cooled to 0°-10° C. Then, 5.0 g (18 mmol) of 2-(2-bromoethyl)benzyl bromide was rapidly added in one portion. The reaction was stirred for 2 h at 0°-10° C. then 24 h at room temperature. The precipitated inorganic salt was removed by filtration and discarded. The solvent was removed under reduced pressure yielding a golden oil. This oil was chromatographed on a reverse phase column (C-18) with methanol-water (1:1) as eluant. The combined fractions were concentrated under reduced pressure to yield 5.6 g (75%) of the product as a white solid, mp 86.0°-86.5° C. IR(nujol): 1785, 1637 cm -1 (C═O). 1 H NMR(CDCl 3 ) δ 1.2 (t, 6H); 1.9 (s, 3H); 2.8-3.5 (m, 4H), 3.6 (5, 2H); 4.2 (q, 4H); 6.8 (s. 1H); 7.2 (m, 4H). Anal. Calcd. for C 18 H 24 NO 5 Br: C, 52.18; H, 5.84; N, 3.38. Found: C, 52.26; H, 5.86; N, 3.34.
EXAMPLE V
Ethyl 3-[2-(2-diethylphosphonoethyl)phenyl]-2-acetamido-2-carboethoxy-propanoate
A solution of 5 g (1.2 mmol) of ethyl 3-[2-(2-bromoethyl)phenyl]-2-acetamido-2-carboethoxypropanoate in 10 mL of P(OEt) 3 was stirred at reflux for 4 h. The excess P(OEt) 3 and the volatile by-products were removed from the mixture by distillation under vacuum. The remaining viscous oil was initially purified by column chromatography (C-18, MeOH:H 2 O; 4:1), then by preparative HPLC (C-18, MeOH:H 2 O, 7:3) giving 0.48 g (86%) of the product as a clear viscous oil. IR(Nujol) 1745.9, 1676.5 cm -1 (C═O); 1 H NMR(CDCl 3 ) δ 1.1-1.5 (m, 12H); 1.8-3.1 (complex, m, 7H); 3.7 (s, 2H); 3.8-4.4 (m, 8H); 6.6 (s, 1H), 7.0-7.3 (m, 4H) Anal. Calcd. for C 22 H 34 NO 8 P: C, 56.04; H, 7.27; N, 2.97. Found: C, 55.91; H, 7.31, N, 2.84.
EXAMPLE VI
3-[2-(2-Phosphonoethyl)phenyl]-2-aminopropanoic acid
A solution of 7.9 g (16.8 mmol) of ethyl 3-[2-(2-diethylphosponoethyl)-phenyl]-2-acetamido-2-carboethoxypropanoate in 40 mL of 6N HCl was stirred at vigorous reflux for 14 h. After cooling to room temperature the reaction mixture was concentrated at reduced pressure yielding an oil. This oil was washed with four 25 mL portions of water then dissolved in 20 mL 95% ethanol and propylene oxide added dropwise. The precipitated crude acid was collected by filtration. Recrystallization from dilute ethanol yielded 4.1 g (90%) as a white solid, mp 241°-243° C. IR(Nujol): 1712.5 cm -1 (C═O). 1 H NMR(D 2 O) δ 1.5-2.2 (m, 2H); 2.6-3.3 (m, 4H); 3.9-4.2 (t, 1H); 7.2 (m, 4H). Anal. Calcd. for C 11 H 16 NO 5 P: C, 48.35; H, 5.90; N, 5.13. Found: C, 48.69; H, 6.16; N, 4.95.
EXAMPLE VII
Diethyl 2-(bromomethyl)benzylphosphonate
In a round bottom flask equipped for distillation, 20.0 g (75.8 mmol) of α,α 1 -dibromo-o-xylene and 12.6 g (75.8 mmol) of triethylphosphite were heated with stirring at 70°-75° C. When ethyl bromide ceased distilling off (about 2-3 h), the remaining volatile by-product and triethylphosphite were removed from the mixture by distillation under vacuum. The remaining oil was chromatographed on a column of silica gel with ethyl acetate as eluant. The fractions were combined and concentrated under reduced pressure to yield a yellow oil. IR(neat): 1249; 1164.8; 1038.8; 966.8; 794.5 cm -1 . 1 H NMR (CDCl 3 ) δ 1.0-1.4 (m, 6H); 3.1 (s, 1H); 3.5 (s, 1H); 3.6-4.2 (m, 4H); 4.6 (s, 1H); 7.2 (s, 4H).
Anal. Calculated for C 12 H 18 PO 3 Br: C.
EXAMPLE VIII
Ethyl 3-[2-(diethylphosphonomethyl)phenyl]-2-acetamido-2-carboethoxy-propanoate
To a solution of 0.43 g (18.8 mmol) Na in 50 mL of dry ethanol was added 4.09 g (18.8 mmol) of solid diethyl acetamidomalonate portionwise. This mixture was stirred at reflux under nitrogen for 2 h, then cooled to room temperature. Then, 6.05 g (18.8 mmol) of 2-(diethylphosphonomethyl)benzyl bromide in 40 mL of ethanol was added dropwise and the mixture stirred for 24 h. The salt which precipitated was removed by filtration and the solvent concentrated at reduced pressure to yield a viscous oil. This oil was chromatographed on a column of silica gel with ethyl acetate as eluant. The combined fractions were concentrated under reduced pressure to yield 6.67 g (79%) of the product as a clear oil. IR(neat): 1745.9, 1676.5, 1501.6, 1375.6, 1247.1, 1649.1, 969.4 cm -1 . 1 H NMR (CDCl 3 ) δ 1.0-1.4 (m, 12H); 2.0 (s, 3H); 2.9 (s, 1H); 3.3 (s, 1H); 3.8-4.4 (m, 10H); 5.8-7.4 (m, 5H). Anal. Calcd. for C 21 H 32 NPO 8 0.5H 2 O: C, 54.06; H, 6.92; N, 3.00. Found: C, 53.73; H, 7.11; N, 3.27.
EXAMPLE IX
3-[2-Phosphonomethylphenyl]-2-aminopropanoic acid 532
A solution of 4.5 g (9.8 mmol) of ethyl 3-[2-(diethylphosphonomethyl-phenyl]-2-acetamido-2-carboethoxypropanoate in 50 mL of 6N HCl was stirred at vigorous reflux for 12 hours. After cooling to room temperature the reaction mixture was concentrated at reduced pressure yielding an oil. This oil was washed with three 50 mL portions of water then dissolved in 95% ethanol and an excess of propylene oxide added. The precipitated acid was collected by filtration and recrystallized from dilute ethanol yielding 1.6 g (63%) of the product as a white solid: mp 259°-261° C.; IR(nujol): 1722; 1625; 1128; 1049 cm -1 . 1 H NMR(D 2 O) δ 2.8-3.7 (unresolved, 4H), 4.2 (m, 1H), 77.3 (s, 4H); Anal. Calcd. for C 10 H 14 NO 5 P, 0.25H 2 O: C, 45.55; H, 5.54; N, 5.32. Found: C, 45.57, H, 5.55; N, 5.38.
EXAMPLE X
Ethyl 3-[2-(3-bromopropyl)phenyl]-2-acetamido-2-carboethoxypropanoate
To a stirred solution of 0.61 g (27 mmol) Na in 40 mL of dry ethanol was added portionwise 5.86 g (27 mmol) of solid diethyl acetamidomalonate. This mixture was stirred at reflux under nitrogen for 2 h, then cooled to 0°-10° C. on an ice bath. Then, 8.0 g (27 mmol) of 2-(3-bromopropyl)benzyl bromide in 40 mL of dry ethanol was rapidly added. The reaction mixture was stirred for 2 h at 0°-10° C., then 24 h at room temperature. The precipitated inorganic salt was removed by filtration, and was washed with 20 mL of ethanol and discarded. The combined solvents were removed under reduced pressure yielding an orange colored oil. This oil was chromatographed on a column of silica gel with hexane-ethyl acetate (3:1) as eluant. The combined fractions were concentrated under reduced pressure to yield an oil which solidified upon standing, yield 9.5 g (82%), mp 73°-74.5° C. IR(nujol): 1745, 1648 cm -1 (C═O). 1 H NMR(D 2 O) δ 1.3 (t, 6H); 1.9-2.4 (m, 5H); 2.7 (t, 2H); 3.4 (t, 2H); 3.75 (5, 2); 4.3 (q, 4); 6.6 (s, 1H); 7.0-7.3 (m, 4H). Anal Calcd. for C 19 H 26 NO 3 Br: C, 53.28; H, 6.12; N, 3.27; Br, 18.66. Found: C, 53.33; H, 6.13; N, 3.23; Br, 18.67.
EXAMPLE XI
Ethyl 3-[2-(3-diethylphosphonopropyl)phenyl]-2-acetamido-2-carboethoxy-propanoate
A solution of 7.5 g (17.5 mmol) of ethyl 3-[2-(3-bromopropyl)phenyl]-2-acetamido-2-carboethoxypropanoate in 20 mL of freshly distilled triethylphosphite was stirred at reflux for 6 h. The excess P(OEt) 3 and the volatile by-products were removed from the mixture by distillation under vacuum. The remaining viscous oil was chromatographed on a column of silica gel with ethyl acetate as eluant. The combined fractions were concentrated under reduced pressure to yield 4.2 g (49%) of the product as a viscous yellow oil. IR(neat): 1746, 1680 cm -1 (C═O). 1 H NMR(CDCl 3 ) δ 1.1-2.1 (complex m, 19H); 2.4-2.7 (t, 2H); 3.6 (5, 2H); 3.8-4.3 (m, 8H); 6.55 (s, 1H); 6.9-7.2 (m, 4H).
EXAMPLE XII
3-[2-(3-Phosphonopropyl)phenyl]-2-aminopropanoic acid
A solution of 3.0 g (6.9 mmol) of ethyl 3-[2-(diethylphosphonopropyl)phenyl]-2-acetamido-2-carboethoxypropanoate in 25 mL of 6N HCl was stirred at vigorous reflux 12 h. After cooling to room temperature the reaction mixture was concentrated at reduced pressure yielding an oil. The oil was washed with three 25 mL portions of water then dissolved in 25 mL 95% ethanol and propylene oxide added dropwise. The precipitated acid was collected by filtration. Recrystallization from dilute ethanol yield 0.76 g (38%) as a white solid mp>95° C. (dec.). IR(nujol): 1717.6 cm -1 (C═O). 1 H NMR(D 2 O) δ 1.1-2.0 (complex m, 4H); 2.6-3.1 (m, 4H); 3.35-3.65 (m, 1H); 7.3 (m, 4H). Anal. Calcd. for: C 12 H 18 NO 5 P.H 2 O: C, 47.21; H, 6.60; N, 4.58. Found: C, 47.47; H, 6.72; N, 4.53.
EXAMPLE XIII
Diethyl 2-(3-bromopropyl)benzylphosphonate
In a round bottom flask equipped for distillation, 11.36 g (38.9 mmol) of 2-(3-bromopropyl)benzyl bromide and 6.46 (38.9 mmol) of freshly distilled triethylphosphite were heated with stirring at 100°-110° C. on an oil bath. When ethyl bromide ceased distilling off (about 2 h) the remaining volatile by-products and the triethylphosphite were removed from the mixture by distillation under vacuum. The remaining oil was chromatographed on a column of silica gel with hexame-ethyl acetate (1:1) as eluant. The combined fractions were concentrated under reduced pressure to yield 11.2 g (83%) of the product as a clear oil. IR(neat): 2985, 1496, 1450, 1391, 1252, 1162, 104, 967, 843, 802, 758 cm -1 . 1 H NMR(CDCl 3 ) δ 1.2 (t, 6); 1.8-2.3 (m, 2H); 2.7-3.55 (m, 4H); 3.8-4.2 (m, 2H); 7.1-7.4 (m, 4H).
EXAMPLE XIV
Ethyl 5-[2-(diethylphosphonomethyl)phenyl]-2-acetamido-2-carboethoxypentanoate
To 0.48 g (21 mmol) of sodium in 50 mL of dry ethanol was added 4.56 g (21 mmol) of solid diethyl acetamidomalonate portionwise. This solution was stirred at reflux under nitrogen for 2 h. After cooling to room temperature the solvent was removed under reduced pressure yielding a tan solid. This solid was dried under vacuum about 2 h. The sodium salt of diethyl acetamidomalonate was then suspended in 50 mL of dry toluene and 9.0 g (21 mmol) of diethyl 2-(3-bromopropyl)benzylphosphonate in 25 mL of dry toluene was added dropwise. This solution was stirred at reflux under nitrogen for 20 h. After cooling to room temperature the solid which precipitated was removed by filtration and washed with toluene. The combined toluene solutions were concentrated under reduced pressure to yield a dark oil. This oil was chromatographed on a column of silica gel with ethyl acetate as eluant. The combined fractions were concentrated under reduced pressure yielding 4.2 g (42%) of the product as a yellow viscous oil which solidified upon standing, mp 76°-79° C. IR(neat) 1745.9, 1680 cm -1 (C═O). 1 H NMR(CDCl 3 ) δ 1.0-1.4 (m, 12H); 2.0 (s, 3H); 2.2-3.3 (m, 6H); 3.7-4.4 (m, 8H); 6.8 (5, 1H); 7.0-7.3 (m, 4H). Anal. Calcd. for C 23 H 36 NO 8 P: C, 56.90; H, 7.48; N, 2.89. Found: C, 56.27; H, 7.51; N, 2.86.
EXAMPLE XV
5-[2-Phosphonomethylphenyl]-2-aminopentanoic acid
A solution of 3.8 g (7.8 mmol) of Ethyl 5-[2-diethylphosphonomethyl)phenyl]-2-acetamido-2-carboethoxypentanoate in 25 mL of 6N HCl was stirred at vigorous reflux for 12 h. After cooling to room temperature the reaction mixture was concentrated at reduced pressure yielding an oil. This oil was washed with three 25 mL portions of water then dissolved in 25 mL of 95% ethanol and propylene oxide was added dropwise. The precipitated crude acid was collected by filtration. Recrystallization from dilute ethanol yielded 1.7 g (76%) of the product as a white solid, mp>152° C. (dec.). IR(nujol): 1717.6 cm -1 (C═O). 1 H NMR(D 2 O) δ 1.6-1.9 (broad, 4H); 2.8-3.3 (m, 4H); 3.45 (m, 1H); 7.3.7.7 (m, 4H). Anal. Calcd. for C 12 H 18 NO 5 P. 0.5H 2 O: C, 48.65; H, 6.46; N, 4.73. Found: C, 48.56, H, 6.46; N, 4.72.
EXAMPLE XVI
In vitro Receptor Binding Assays
The potency of the compounds described in examples III, V, VI, IX, XII and IV to inhibit the specific binding of various excitatory amino acid ligands to rat brain membranes was examined using standard in vitro ligand binding techniques. Specifically, compounds were evaluated for potency to inhibit the specific binding of [ 3 H]kainic acid, [ 3 H]KA, RS-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid [ 3 H]AMPA, [ 3 H]DL(±)2-amino-7 phosphono heptanoic acid [ 3 H]AP7.
The methods were as follows: rat forebrain membranes were prepared as described by Enna and Synder (Mol. Pharmacol, 13, 422-453, 1977) and the final pellet was washed three additional times by centrifugation (45,000 g; 10 min; 4° C.) with intermittent resuspensions (20 vol; w/v) in fresh buffer appropriate to the assay. For the [ 3 H]AP4 assay, tissue was used immediately. For all other procedures, tissue was stored frozen (-40° C.) until use. All assays were performed using triplicate incubations. Radioactivity was determined using conventional liquid scintillation counting after solubilizing the pellet in 1 mL Protosol (New England Nuclear, Boston, MA) and following the addition of 6 mL of Enconofluor (New England Nuclear, Boston, MA).
Specific [ 3 H]AP4 (specific activity (S.A.)=26.1 Ci/mmol, New England Nuclear, Boston, MA) binding was studied according to the method of Butcher et al. (Brit. J. Pharmacol., 80, 355-364, 1983) using HEPES KOH buffer (0.05 M; pH 7.1). Incubations (2mL) were conducted for 45 min at 37° C. and the reaction was terminated by centrifugation (45,000 g; 10 min; 4° C.). The supernatant was decanted and the pellet washed rapidly and superfically with 2×3.5 ml of ice cold buffer. Final ligand concentration in the assay was 50 nM and L-glutamate (10- 3 M) was used to define non specific binding.
Specific [ 3 H]AMPA (S.A.=25.6 Ci/mmol, New England Nuclear) binding was examined according to the method of Murphy et al., (Soc. Neurosci. Abs., 11, 109, 1985) using Tris HCL buffer (0.05M, pH 6.9; 23° C.) containing 100 mM KSC. Following pretreatment of tissue with Triton-X-100 (0.05%; v/v) for 30 min (37° C.) incubations (2 mL) were conducted for 60 min at 4° C.). The supernatant was decanted and the pellet washed rapidly and superficially with 2×3.5 mL of ice cold buffer. Final ligand concentration in the assay was 16 nM and L-glutamate (10- 3 M) was used to define nonspecific binding.
Specific [ 3 H]AP7 (S.A.=58.4 Ci/mmol, New England Nuclear) binding was examined as described by Ferkany and Coyle (Life Sci., 33, 1295-1305, 1983) using Tris citrate buffer (0.05M; pH 7.5; 23° C.). Following preincubation of the tissue (30 min; 37° C.), incubation (2 ml) were conducted for 90 min at 37° C. and the reaction was terminated by centrifugation (45,000 g; 10 min; 4° C.). The supernatant was decanted and the pellet washed rapidly and superficially wth 2×3.5 mL of ice cold buffer. Final ligand concentration in the assay was 500 nM and L-glutamate (10- 3 M) was used to define nonspecific binding.
Specific [ 3 H]KA (S.A.=60 Ci/mmol, New England Nuclear) binding was examined according to the methods of London and Coyle (Mol. Pharmacol., 15, 492-505, 1979) using Tris HC; buffer (0.05M; pH 7.4; 23° C.). Incubations 2 mL) were performed for 90 min at 4° C.) and the reaction terminated by centrifugation 45,000 g; 10 min; 4° C.). The supernatant was decanted and the pellet washed rapidly and superfically with 2×3.5 ml of ice cold buffer. Final ligand concentration in the assay was 5 nM and L-glutamate (10-M) was used to define nonspecific binding.
Results are reported in Table 1. When tested at final concentration of 100 uM compounds III, V, VI, IX, XII and IV inhibited less than 20 percent of specifically bound [ 3 H]KA or [ 3 H]AMPA. Similarly, compound IX failed to inhibit the specific binding of [ 3 H]AP4 and [ 3 H]AP7 when tested at 100 uM concentration. Compounds III, VI, XII and XV inhibited the specific binding of [ 3 H]AP4 and [ 3 H]AP7 in a concentration dependent manner with the order of potency in each assay being XV>III>XII≧VI. Whereas compounds III, XII and XV were equipotent to the α-amino-ω-phosphono acid, DL(±)AP7 to inhibit both specific [ 3 H]AP4 and [ 3 H]AP7 binding, compound VI was 3-10 fold less potent in this regard. Further, compound VI effectively discriminated between the two assays and was more potent to inhibit the specific binding of [ 3 H]AP7 than the binding of [ 3 H]AP4.
TABLE I______________________________________Potency of Example Compounds to Inhibit Specific [.sup.3 H]Excitatory Amino Acid Binding to Rat Brain MembranesIC.sub.50 (uM)Example [.sup.3 H]AP4 [.sup.3 H]AP7 [.sup.3 H]Kainate [.sup.3 H]AMPA______________________________________XV 1.03 2.29 >>100 >>100III 6.8 6.1 >>100 >>100XII 9.5 N.T. >>100 >>100VI 16.7 52.5 >>100 >>100IX >>100 >>100 >>100 >>100V >>100 >>100 >>100 N.T.AP7 5.1 6.8 >>100 >>100______________________________________ Methods have been described in the text. Values shown are the means of at least three separate determinations performed in triplicate and using eight concentrations of drug. Where values are >>100 uM, this indicates the highest concentration of drug tested and, that less than 20 percent o the specifically bound ligand was displaced.
EXAMPLE XVII
Protection Against Maximal Electroshock Seizures (MES)
The anticonvulsant properties of compounds III, V, VI, IX, XII and XV and, of the reference compound DL(±)P7 against seizures induced by maximal electroshock were evaluated.
For testing, electrodes were clipped to the ears of male CF-1 mice (20-25 g; Charles Rivers), and a current of 0.5 mA was delivered for 0.2 seconds to produce seizures. Anticonvulsant activity was indicated by abolition of the extensor component of the seizure and was defined as hindlimb extension that did not exceed the 90 degree angle with the plane of the body. Data was calculated as the percent of mice not displaying hindlimb extension as described.
Drugs were disolved in a solution of propylene glycol and distilled water (5:95; v/v). For i.c.v. administration, drugs were administered in a final volume of 5 uL, fifteen minutes prior to testing. For i.p. administration, drugs were delivered in a volume of 12.5 ml/kg, thirty minutes prior to testing.
Results are reported in Table 2. As expected, the reference compound AP7 afforded dose-dependent protection against MES-induced seizures with calculated ED 50 's of 8.4 ug (n=8) and 127 mg/kg (n=16) following i.c.v. and i.p. injection, respectively. When tested at a mole dose equivalent to 1 times or twice the ED 50 of the reference compound, examples III, V, VI, XII and XV were without effect on MES-induced convulsions by either route of administration. Example IX afforded limited protection against MES-induced seizures with an estimated ED 50 of 15 ug (i.c.v.) and ED 25 of 500 mg/kg (i.p). Higher doses of the example IX could not be tested due to the appearance of marked ataxia in some animals.
TABLE II______________________________________Potency of Example Compoundsto Antagonize Maximal Electroshock ofPentylenetetrazol-Induced Seizures in Male CF-1 MiceED.sub.50MES PTZ i.c.v. i.p. i.c.v. i.p.Example (ug) (mg/kg) (ug) (mg/kg)______________________________________AP7 8.3 127 1.8 199VI >100 N.T. 3.2 >>350IX 16 500* 24 >>250V >>100 N.T. >>28 350**III N.T. >>250 >>6 >>500XII >>23 >>155 >>5 >>300XV >>22 >>150 >>5 >>300______________________________________ Methods have been described in the text. Where ED.sub.50 values are shown dose response curves were generated using at least 5 concentrations of th indicated agent with 6-8 animals at each drug concentration. Where ED.sub.50 is shown as (>>) this indicates the maximum drug dose tested an the fewer than 20 percent of the tested animals were protected. *highest drug dose tested; ED.sub.25 **highest drug dose tested; 50 percent of animals protected from seizures 3 of 7 animals dead prior to end of observation period.
EXAMPLE XVIII
Protection Against Pentylenetetrazol-induced Seizures (PTZ)
The anticonvulsant properties of compounds III, V, VI, IX, XII and XV and, of the reference compound, DL(±)AP7 against seizures induced by pentylenetetrazol (PTZ) were examined.
For testing, PTZ was dissolved in saline (0.9%; w/v) and administered to male CF-1 mice (Charles Rivers; 20-25 g) at a dose of 85 mg/kg fifteen minutes (i.c.v.) or thirty minutes (i.p.) after the administration of the test compound. Mice were observed for ten minutes following the administration of PTZ and seizures were scored as present or absent. Data were expressed as the percent of animals showing seizures activity.
For testing, examples V, VI, XLL, XV and the reference compound were dissolved in propylenegylcol and water (95:5, v/v) whereas examples III and IX were dissolved in 0.2M bicarbonate. Drugs were administered in a volume of 5 uL or 12.5 mL/kg for i.c.v. and i.p. administration, respectively.
Results of testing are shown in Table 2. When administered at drug amounts equal to 1 times or 2 times the ED 50 of the reference compound to attenuate PTZ-induced seizures, examples III, XII and XV were devoid of activity followed i.c.v. or i.p. administration. Example V, intermediary compound to the synthesis of example VI, provided limited seizure protection (4 of 7 animals) following i.p. injection of 350 mg/kg. Administration of higher doses (500 mg/kg) of example V resulted in mortality in 40 percent of the tested animals and seizure protection was not scored.
Example VI was equipotent to the reference compound to attentuate PTZ-induced convulsions following i.c.v. administration (Table 2). However, following i.p. administration at doses up to 350 mg/kg. example VI failed to significantly protect animals in this seizure model.
Example IX was similarly potent to protect mice from PTZ-induced seizure activity when administered intraventricularly having an ED 50 10-fold greater than the reference compound and 6-fold greater than example VI. As was the case for example VI, example IX was essentially devoid of anticonvulsant activity when administered via intraperitoneal injection.
Compounds VI and IX are potent anticonvulsants in the PTZ-induced seizure model following i.c.v. administration and are distinguished from the reference compound by their selectivity to confer protection in this model vis-a-vis MES-induced seizure activity.
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The invention pertains to novel, potent anticonvulsants, analgesics and cognition enhancers achieving their action through the antagonism of specific excitatory amino acid neurotransmitter receptors. In particular, the invention is directed to ω-[2-phosphonoalkyleneyl)phenyl]-2-aminoalkanoic acids having general formula: ##STR1## Wherein R 1 and R 2 are the same or different and are selected from the group consisting of hydrogen, lower alkyl, halogen, --CH═CH--CH═CH═, amino, nitro, trifluoromethyl or cyano; n and m=0, 1, 2, or 3; and the pharmaceutically acceptable salts and derivatives thereof.
Examples of specific preferred compounds of general formula are selected from the group consisting of: 4-[2-phosphonomethylphenyl]-2-aminobutanoic acid, ethyl 3-[2-(2-diethylphosphonoethyl)phenyl]-2-acetamido-2-carboethoxypropanoate, 3-[2-(2-phosphonomethyl)phenyl]-2-aminopropanoic acid, ethyl 3-[2-(3-bromopropyl)phenyl]-2-acetamido-3-carboethoxypropanoate, ethyl 3-[2-(3-diethylphosphonopropyl)phenyl]-2-acetamido-2-carboethoxypropanoate, ethyl 3-[2-(3-phosphonopropyl)-phenyl]-2-aminopropanoic acid, ethyl 5-[2-(diethylphosphonomethyl)-phenyl]-2-acetamido-2-carboethoxypentanoate, and 5-[2-phosphonomethylphenyl]-2-aminopentanoic acid.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of aeronautical turbine engines and is aimed in particular at the air inlet of the turbine engine, the latter comprising the engine itself and the nacelle in which it is housed.
2. Description of the Related Art
A turbine engine generally comprises a gas generator formed of one or more sets of rotors rotating about one and the same axis. Each set, known as a spool, is made up of a compressor and of a turbine which are usually connected by a shaft or drum, and are arranged one upstream and the other downstream of a combustion chamber in relation to the flow of gases through the engine. Associated with this gas generator is a fan or a simple or multiple set of fan blades that it drives.
When the rotor of the fan or set of fan blades is positioned in front of the engine, the air inlet of the generator is situated downstream of this rotor. Foreign bodies, such as birds, hail, water and stones, liable to be absorbed by the generator are at least partially slowed or halted by the front rotor which, because of its inertia and its size, partially forms a screen, or are deflected by a centrifugal effect of the fan toward the secondary flow path. Such protection does not exist on engines the fan or set of fan blades rotor of which is not positioned upstream of the gas generator air inlet.
Such is the case of an unducted fan, or UDF, engine or of an “open rotor” engine. This type of engine comprises a pair of sets of fan blades, which are contrarotatory, and arranged radially on the outside of the nacelle enveloping the generator, in line with two turbine impellers by which they are directly driven. The gas generator is a single flow generator. This type of engine is discussed in the patent application FR 2 606 081 in the name of the Applicant company.
One solution might be to strengthen the first compressor stages, but such reinforcement would lead to a sizing of the elements which is somewhat unfavorable in terms of mass and size, because these need to be capable of withstanding direct impacts.
BRIEF SUMMARY OF THE INVENTION
It is an object of the invention to produce an air inlet that would reduce the energy of impact of bulky objects in such a way that when these reach the compressor they have lost enough energy that they do not damage the components of that compressor.
Another object of the invention is to produce an air inlet able to deflect objects of smaller size such as grains of sand, ice, stones and water and discharge them without losing too much energy.
Specially designed air inlets for engines fitted to helicopters or to vertical take-off and landing (VTOL) aircraft are known. These for example comprise means that deflect the air flow at the inlet with, downstream of the deflection point, means that trap ingested objects, notably sand.
The present invention is aimed at an air inlet that is an improvement over the air inlets of the prior art and protect the engine against the ingestion of foreign objects while at the same time maintaining the aerodynamic performance of the nacelle.
The invention proposes an assembly of a gas turbine engine and of a nacelle in which it is housed with an air inlet fairing forming an air inlet comprising:
a foreign-object deflection member which, with said fairing, forms an air intake duct and, downstream of the deflection member, a secondary deflection passage, a main engine air supply passage,
said air intake duct being designed to deflect at least some of the foreign objects that have been aspirated by the air inlet toward the secondary deflection passage, characterized in that the secondary deflection passage is configured in such a way that the speed at which the air passing through it flows is increased from upstream to downstream, the secondary passage having an outlet with an opening that opens out in the exterior wall of the nacelle.
Through the invention, it is thus possible to maintain aerodynamic performance and limit the overall drag of the nacelle. Thus, the cross section of the secondary passage, transverse to the direction in which the air flows, is of an area that decreases between the inlet and the outlet of the secondary passage.
According to one advantageous embodiment, the reduction in cross sections is azimuthal. More specifically, the secondary deflection passage is formed of at least two separate ducts with an annular inlet that is common and outlets with openings distributed around the periphery of the nacelle.
The air discharge opening section in the wall of the nacelle is preferably configured so that the airflow is directed along the axis of the engine.
The foreign-object deflection member preferably conceals the main passage from any ballistic trajectory passing through the air inlet. According to one advantageous embodiment it is in the shape of an axisymmetric bullet which forms an annular air intake passage with the air inlet fairing which is likewise of annular shape.
According to one embodiment, the secondary deflection passage is formed of at least two separate ducts with an annular inlet that is common and outlets with openings distributed around the periphery of the nacelle. For example, the secondary passage may comprise four ducts or five or more.
According to another embodiment, in an assembly formed of a gas turbine engine and of a nacelle in which it is housed, the nacelle comprising an air inlet fairing and a removable cowling element in the continuation of said air inlet fairing, said assembly is characterized in that the secondary deflection passage comprises at least one portion of secondary passage that forms a deflection scoop and is secured to said removable cowling element.
This solves the problem of installing one or more object-deflection ducts while at the same time maintaining satisfactory aerodynamic performance in an engine environment that is tight on space. The solution allows an isostatic arrangement to be maintained, that transmits the least possible amount of load through said secondary passage portion that forms the deflection scoop.
Further, the solution allows an engine weight saving by comparison with an embodiment in which the engine has to be capable of withstanding the impacts directly.
This solution is well suited to an assembly in which the cowling element is articulated about an axis parallel to the axis of the engine so as to uncover the engine.
This solution makes maintenance easier: with the cowlings open, the duct portion or portions do not impede gas turbine engine maintenance. The air inlet components liable to be impacted can be inspected. They can be removed and easily exchanged in the event of impact.
According to one preferred embodiment, the assembly of a gas turbine engine and of a nacelle has a deflection member in the shape of an axisymmetric bullet which forms an annular air intake passage with the air inlet fairing which is likewise of annular shape, the deflection member being supported at least in part by a first casing having an internal hub, by being engaged in said internal hub.
More particularly, said first hub casing is fixed to the engine and notably the first hub casing is fixed to the engine by means of a second hub casing.
Using this embodiment, the life and reliability of the assembly is optimized, the load paths and assembly being simple.
Advantageously, the second hub casing forms a plane for suspending the engine from an aircraft.
The assembly of the invention also comprises the following features considered alone or in combination:
With the cowling element being articulated about an axis parallel to the axis of the engine so as to uncover the engine, the portion of secondary deflection passage secured to the articulated cowling element has upstream surfaces that press in a fluidtight manner against bearing surfaces forming the secondary passage inside the air inlet fairing. In particular, said bearing surfaces are formed on the hub casing.
The secondary passage is configured in such a way that the speed at which the air passing through it flows is increased from upstream to downstream, the secondary passage having an outlet opening into the exterior wall of the nacelle. This increase in speed is obtained by reducing the cross section of the secondary passage transversally to the direction in which the air flows between the inlet and the outlet of the secondary passage. This reduction in transverse cross section is preferably azimuthal so as to obtain outlet orifices which are distributed at the surface of the nacelle.
The foreign-object deflection member preferably conceals the main passage from any ballistic trajectory passing through the air inlet. This avoids the direct ingestion of any foreign object into the engine.
The invention is aimed more specifically at engines of the unducted fan type, the sets of fan blades being arranged downstream of the engine inlet.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention will be better understood and other objects, details, features and advantages thereof will become clearly apparent during the course of the detailed explanatory description which follows, of one or more embodiments of the invention which are given by way of purely illustrative and nonlimiting examples with reference to the attached schematic drawings. In these drawings:
FIG. 1 is a schematic partial axial section of a turbine engine of the unducted fan type, the air inlet of which is an air inlet according to the invention,
FIG. 2 is a perspective view of the air inlet of figure 1 and shows the elements of the air inlet with hidden detail according to a first embodiment,
FIG. 3 is an exploded perspective view of the assembly of the engine and of its nacelle according to another embodiment, in which the scoops are incorporated into a nacelle comprising two cowlings articulated about longitudinal axes,
FIG. 4 is a view in section of the embodiment of FIG. 3 , showing the interface between the second hub casing and the cowling elements, with the cowling open,
FIG. 5 is a view in cross section of the embodiment of FIG. 3 , showing the interface between the second hub casing and the cowling elements, with the cowling closed,
FIG. 6 is a cross section of FIG. 4 , passing through the axis of the machine,
FIG. 7 is a cross section of FIG. 4 not passing through the axis of the machine,
FIG. 8 is a schematic partial axial section of a turbine engine of the unducted fan type with an alternative form of embodiment of the invention regarding the second hub casing.
DETAILED DESCRIPTION OF THE INVENTION
Reference is made first of all to FIG. 1 which depicts the main constituent parts of an unducted fan turbine engine 10 . From upstream to downstream, in the direction in which the gases flow within the turbine engine, it comprises a compressor 12 , an annular combustion chamber 14 , a high-pressure turbine 16 only the casings of which are visible. Downstream of the high-pressure turbine 16 are two low-pressure turbines, not visible, which are contrarotatory, which means to say that they rotate in opposite directions about the longitudinal axis A of the engine.
Each of these downstream turbines rotates as one with an external set of fan blades 22 , 24 extending radially on the outside of the nacelle 26 of the turbine engine, this nacelle 26 being substantially cylindrical and extending along the axis A from the air inlet around the compressor 12 , the combustion chamber 14 and the turbines.
The flow of air 28 that enters the engine is compressed and then mixed with fuel and burnt in the combustion chamber 14 , the combustion gases then passing through the turbines to drive the rotation of the sets of fan blades 22 , 24 which provide most of the thrust generated by the turbine engine. The combustion gases leaving the turbines are expelled through a jet pipe 32 (arrows 30 ) to increase the thrust.
The sets of fan blades 22 , 24 are arranged coaxially one behind the other and comprise a plurality of blades evenly distributed about the axis A of the turbine engine. These blades extend substantially radially and are of the variable-pitch type, which means that they are able to rotate about their axes in order to optimize their angular position according to the operating conditions of the turbine engine.
The nacelle 26 comprises an upstream air inlet fairing 26 a of annular shape. A foreign-object deflection member 40 is positioned inside the air inlet fairing 26 a . With the interior wall 26 a 2 of the air inlet fairing 26 a it delimits an air inlet passage 41 for the engine. This passage 41 in this instance is annular. The object-deflection member is of ovoid overall shape, its axis co-linear with the axis AA of the engine. One vertex 40 a of the ovoid points upstream of the upstream edge 26 a 1 of the fairing 26 a . The deflection member has a maximum diameter on its widened part at 40 b downstream of the edge 26 a 1 . The deflection member is advantageously supported by a hub casing, not depicted, the arms of which radiate out between an interior hub in which the deflection member is mounted and an exterior shell ring.
Downstream of the widened part 40 b , the air inlet passage 41 widens and splits into two concentric passages: an interior main passage 42 and a secondary passage 43 exterior to the previous one. The main passage 42 leads to the inlet of the compressor 12 and supplies the engine with primary air. The secondary passage 43 leads into the nacelle 26 on the outside of the various casings of the engine. It opens into the wall of the nacelle 26 through an opening 43 a therein.
The passage is delimited by two radial or substantially radial walls 43 2 c and 43 2 d which extend longitudinally between the edge 43 b and the opening 43 a , and by two walls in the form of cylinder portions, a radially interior wall 43 f and a radially exterior wall 43 e . The latter is in the continuation of the interior wall 26 a 2 of the air inlet fairing 26 a.
According to the embodiment depicted, the engine comprises two secondary passages 43 2 and 43 2 ′ extending from the upstream edge 43 b of the surface that splits the incoming airflow between the two, main 42 and secondary 43 , passages. According to one feature of the invention, the secondary passages 43 2 and 43 2 ′ have a cross section transverse to the direction of the flow which decreases progressively from the flow separation edge 43 b . This reduction in cross section leads to an increase in the speed of the air in the secondary passage 43 . Thus on the one hand, any ingestion of air through the outlet openings 43 a of the secondary passage 43 is avoided and on the other hand, the airflow contributes toward propulsion.
For preference, the reduction in cross section transverse to the direction of flow from upstream to downstream is obtained by an azimuthal reduction in cross section, the separation between the two longitudinal walls 43 2 c and 43 2 d decreasing progressively between the edge 43 b and the opening 43 2 a. The radial thickness, between the two cylinder portions, of the secondary passage for deflecting the foreign objects is constant or substantially constant from the inlet corresponding to the edge 43 b as far as the opening 43 2 a . As may be seen in FIG. 2 , the opening 43 a of each passage 43 extends over a circumferential width that is very much smaller than that of the inlet defined by a part of the edge 43 b and which extends over half a circumference thereof.
The function of the various elements that make up this air inlet is as follows. If a foreign object is aspirated in flight through the air inlet it strikes the deflection member 40 off which it ricochets. Its path is deflected toward the interior wall of the inlet fairing. Downstream of the widened part of the deflection member, the object is directed toward one of the deflection passages 43 2 or 43 2 ′ whence it is led out through the opening 43 a.
The deflection member is advantageously supported by a first hub casing 51 the arms of which radiate out between an interior hub in which the deflection member is mounted and an external shell ring. The first hub casing 51 is itself supported by a second hub casing 52 positioned downstream. This second casing 52 is fixed to the engine, for example to the casing of the compressor 12 .
FIG. 3 depicts an exploded perspective view of the assembly of FIG. 1 , according to an alternative form of embodiment involving four scoops. The nacelle 26 comprises, downstream of the air inlet fairing 26 a , a cowling formed of two cowling elements 26 b and 26 c articulated to the pylon 60 via which the assembly is attached to the aircraft. The elements are each articulated about an axis parallel to the axis AA of the engine. According to the embodiment depicted, each cowling element 26 b or 26 c supports two scoops, one a top scoop 43 4 ′, the other a bottom scoop 43 4 ″. The four scoops are portions of secondary passage 43 . Here they have identical profiles because they are arranged symmetrically about the engine axis.
A scoop 43 4 ′ or 43 4 ″ of the secondary passage 43 is delimited by two radial or substantially radial walls 43 1 c and 43 4 d which extend longitudinally between the edge 43 b and the opening 43 4 a and by two walls in the form of cylinder portions, one being a radially interior wall 43 1 f and the other a radially exterior wall 43 4 e . The latter is in the continuation of the interior wall 26 a 2 of the air inlet fairing 26 a when the cowling is closed. The scoops extend from the upstream edge 43 b of the surface that splits the incoming airflow between the two, main 42 and secondary 43 , passages.
According to one feature of the invention, the scoops of the secondary passage 43 have a cross section transverse to the direction of flow which decreases progressively from the edge 43 b that separates the flows. This reduction in cross section leads to an increase in the speed of the air in the secondary passage 43 . Thus, on the one hand any ingestion of air through the outlet openings 43 4 a of the secondary passage 43 is avoided, and on the other hand the air flow contributes toward propulsion.
For preference, the reduction in cross section transverse to the direction of flow from upstream to downstream is obtained by an azimuthal reduction in cross section, the separation between the two longitudinal walls 43 4 c and 43 4 d decreasing progressively between the edge 43 b and the opening 43 4 a . The radial thickness, between the two cylinder portions, of the scoops is constant or substantially constant from the inlet corresponding to the edge 43 b as far as the opening 43 a . As can be seen in FIG. 2 , the opening 43 4 a of each scoop 43 4 ′ or 43 4 ″ extends over a circumferential width very much smaller than that of the inlet defined by a part of the edge 43 b and which extends over a quarter of the circumference thereof. FIGS. 4 and 5 show a cowling element 26 b in the closed position, FIG. 4 , and in the open position, figure 5 allowing the engine to be inspected.
According to another feature of the invention, the deflection member 40 is supported by the engine by means of two hub casings 51 and 52 . The first hub casing 51 is formed of an interior hub 51 in and of an exterior hub or shell ring 51 ex , which are connected by radial arms 51 b . The space between the two hubs 51 in and 51 ex defines the opening of the air inlet passage 41 . The interior hub 51 in holds the bullet of the deflection member 40 . The second hub casing 52 likewise comprises an interior hub 52 in and an exterior hub 52 ex which are connected by radial arms 52 b . The second hub casing 52 defines part of the secondary passage 43 .
FIG. 6 , which is a partial longitudinal sectioned view of FIG. 5 , shows the layout of two hub casings. The two casings 51 and 52 are joined together by bolting together their respective exterior shell ring 51 ex and 52 ex . The interior hub 52 in of the second hub casing is itself secured to the engine casing, for example to the casing of the compressor 12 which cannot be seen in FIG. 6 . In this way, the deflection member 40 is held on the downstream gas turbine engine. This form of assembly avoids any vibration thereof.
As can be seen in FIGS. 4 and 5 , the cowling element 26 b or 26 c is articulated about an axis parallel to the axis AA. The scoops are positioned in the downstream continuation of the second casing 52 and are configured in such a way as to allow a fluidtight assembly between the second hub casing 52 and the scoops 43 4 ′ or 43 4 ″. In relation to FIGS. 6 and 7 which are respectively views in longitudinal section passing through the axis and not passing through the axis of the secondary passage, sealing between the casing 52 and the scoops 43 4 ′ and 43 4 ″ is afforded as follows.
Seals 70 are interposed between the downstream continuations of the two hub shell rings 52 ex and 52 in and the upstream continuations of the two cylindrical walls 43 4 e and 43 4 f of the scoops 43 4 ′ and 43 4 ″. These are, for example, lip seals.
As may be seen in FIG. 6 , seals are interposed between the lateral walls 43 4 c and 43 4 d of the scoops and the flanks of the radial arms 52 b of the hub casing 52 . It may be seen that, for preference, the lateral walls 43 4 c and 43 4 d of the scoops are inclined with respect to the normal to the cylindrical walls in order to center the scoops with respect to the radial arms 52 b.
The way in which the various elements that make up this air inlet work is as follows. If a foreign object is aspirated in flight by the air inlet it strikes the deflection member 40 off which it ricochets. Its trajectory is deflected toward the interior wall of the inlet fairing 26 a . Downstream of the widened part of the deflection member, the object is directed toward one of the scoops of the deflection passage 43 4 ′ or 43 4 ″ whence it is led out through the opening 43 4 a . If, as a result of ricochet, it is aspirated into the main passage, it has lost enough energy that it does not damage the engine.
According to one alternative form of embodiment, depicted in FIG. 6 , of the second hub casing, the latter is designed to form what is known as the intermediate casing in the engine front suspension plane.
The engine of FIG. 8 is the same as that of FIG. 1 . The difference lies in the second hub casing referenced 152 . This second hub casing 152 comprises an interior hub 152 in forming a support for the front bearing of the engine shaft. It comprises a middle hub 152 m corresponding to the interior hub of the hub casing of the previous embodiment and an exterior hub 152 ex corresponding to the exterior hub of the preceding embodiment. The front attachment means 161 for attaching the engine to the aircraft are attached to this exterior hub 152 ex . One example of an engine suspension has been depicted schematically. It comprises a pylon 160 which at one end is attached to the aircraft and to which the engine is secured. The attachment of the engine comprises said front attachment 161 , a rear attachment 162 in the rear suspension plane and thrust rods 163 . The air intake passage 42 is defined between the two, interior 161 in and middle 152 m , hubs between which the vanes 152 r of the first, flow-straightening, stage of the compressor are formed.
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An assembly including a gas turbine engine and a nacelle in which the engine is housed, the nacelle including an air intake fairing that forms an air inlet and includes: a member for deflecting foreign objects, which together with the fairing, forms an air intake duct; and, downstream from the deflecting member, a secondary deflecting channel, and a main channel for supplying air to the engine. The air intake duct is configured to deflect at least some of the foreign objects sucked in through the air inlet towards the secondary deflecting channel. The secondary deflecting channel is shaped such that the flow velocity of the air flowing therethrough increases from upstream to downstream, the secondary channel having an outlet with an opening leading into the outer wall of the nacelle.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of copending application Ser. No. 874,402 filed Feb. 1, 1978, now U.S. Pat. No. 4,138,398, which in turn is a continuation-in-part of copending application, Ser. No. 754,189, filed Dec. 27, 1976 and now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the preparation of cyclic ureas, and, more particularly, is concerned with the preparation of bis cyclic ureas which can act as masked diisocyanates, the diisocyanates produced thereby, and the stable one-component polyurethane forming systems containing said bis cyclic ureas.
2. Description of the Prior Art
One-can, or the commonly named one-component, polyurethane forming systems are well known, particularly, in the coating art; see for example, Saunders & Frisch, Polyurethanes: Chemistry and Technology, Parts I (pp. 8 and 118-121) and II, (pp. 453-454), 1963 and 1964 respectively, Interscience Publishers, John Wiley and Sons, New York, N. Y., and further references cited therein. The one-component systems call for the use of a "blocked" or "disguised" isocyanate with a polyol. Upon heating the one-component system, the isocyanate groups are released to react with the polyol to form the polyurethane. Unless, and until, the systems are heated they remain shelf stable and avoid the need to store and mix a number of separate components.
However, the blocked isocyanates suffer from the severe disadvantage that when the blocking agent is released during the curing phase, it is liberated into the resin where it may remain and have a deleterious effect, or, alternatively, be vaporized off where it must either be collected or released to the atmosphere. Since the commonest blocking agent is phenol this gives rise to both safety and environmental problems, not to mention the economic ones.
We have now found a novel class of bis cyclic ureas which are particularly useful in stable one-component polyurethane systems where they function as masked isocyanates. When the system is heated the bis ureas dissociate to form only the diisocyanate thereby eliminating the prior art problem of a released blocking agent.
Furthermore, the compounds prepared from the bis cyclic ureas are, themselves, a novel class of amide containing diisocyanates which are useful monomers in applications other than one-component polyurethane systems and are very simply prepared from said ureas.
SUMMARY OF THE INVENTION
This invention comprises bis cyclic ureas having the formula ##STR2## wherein C n H 2n represents alkylene from 4 to 12, inclusive, provided there are at least 4 carbon atoms in succession in the chain and R is a divalent radical selected from the group consisting of ##STR3## wherein C x H 2x represents alkylene from 1 to 8 inclusive, and ##STR4##
The invention also comprises a process for the preparation of the novel bis cyclic ureas (I).
The invention also comprises a process for converting a bis cyclic urea (I) into a diisocyanate having the formula
OCN--C.sub.n H.sub.2n --NH--R--NH--C.sub.n H.sub.2n --NCO (II)
wherein C n H 2n and R are as defined above.
The invention also comprises the diisocyanates having the formula (II) set forth above.
The invention also comprises a storage stable composition, capable of forming a polyurethane resin upon heating said composition to a temperature in the range of about 100° C. to about 250° C., said composition comprising a mixture of a bis cyclic urea (I) and a polymeric polyol.
The invention also comprises a polyurethane resin prepared by reacting a bis cyclic urea (I) with a polymeric polyol.
The diradical --C n H 2n -- means an alkylene radical having from 4 to 12 carbon atoms, inclusive, such as butylene (tetramethylene), pentylene (pentamethylene), hexylene (hexamethylene), heptylene (heptamethylene), octylene (octamethylene), nonylene (nonamethylene), decylene (decamethylene), undecylene (undecamethylene), dodecylene (dodecamethylene), and isomeric forms thereof provided there are at least 4 carbon atoms in succession in the chain separating the valencies
The diradical --C x H 2x -- means an alkylene radical having from 1 to 8 carbon atoms, inclusive, such as methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, and isomeric forms thereof.
The term "storage stable composition" means a composition capable of standing for an indefinite period of time at a temperature of about 20° C.-30° C. without undergoing a chemical change.
The term "polymeric polyol" means any organic polyol having an average hydroxyl equivalent weight of from about 30 to about 1,500 and having from about 2 to about 8 hydroxyl groups per molecule.
The term "polymeric diol" means a polymeric polyol defined above and having 2 hydroxyl groups.
The term "difunctional extender" means a difunctional active hydrogen containing compound inclusive of glycols, diamines, amino-alcohols, and the like.
DETAILED DESCRIPTION OF THE INVENTION
The novel bis cyclic ureas of the present invention having the formula (I) set forth above are easily prepared in a novel process using the Schotten-Baumann reaction conditions for the acylation of amines or ureas; for example, see Synthetic Organic Chemistry by R. B. Wagner and H. D. Zook, p. 647, 1953, John Wiley and Sons, New York, N. Y. Typically, the appropriate cyclic urea (III) and diacid halide (IV) are reacted in an inert organic solvent at a molar ratio of 2:1 respectively and in the presence of a 2 molar proportion of an acid acceptor base compound to remove the 2 moles of HX formed from the reaction in accordance with the following equation ##STR5## wherein the diradicals --C n H 2n -- and --R-- are as defined above and X is a halogen selected from the group consisting of fluorine, chlorine, bromine, and iodine.
A preferred class of novel bis cyclic ureas (I a) in accordance with the present invention is that prepared from the cyclic urea (III a) and a diacid halide (IV a) in accordance with the following equation ##STR6## wherein n is an integer from 4 to 6 inclusive.
The preparative conditions involve procedures well known to those skilled in the art and are not critical to the present invention and optimum conditions can be easily determined by trial and error. The reaction temperature can range from about 20° C. to about 100° C. and preferably is from about 20° C. to about 80° C. The reaction time is advantageously from about 10 minutes to about 8 hours.
Typical solvents for the reaction include ethylene dichloride, chlorobenzene, ortho-dichlorobenzene, methylethyl ketone, acetonitrile, diethyleneglycol dimethyl ether, ethyleneglycol dimethyl ether, and the like.
Any base capable of removing hydrohalic acids from the reaction may be used and includes either an inorganic or organic base although the latter is generally preferred. Typical inorganic bases which can be employed are sodium hydroxide, potassium hydroxide, calcium oxide, and the like. Typical organic bases include tertiary amines such as pyridine, triethylamine, tributylamine, and the like. Generally speaking, when the tertiary amines are employed they form insoluble amine hydrohalide salts which are easily removed by filtration whereas an inorganic base such as sodium hydroxide results in the formation of the sodium halide salt and water which are both easily separated from the bis cyclic urea using liquid extraction procedures well known to those skilled in the art.
The bis cyclic ureas are readily obtained from the reaction mixture using standard product isolation techniques known to those skilled in the art. Generally speaking, after the hydrohalide salt is removed from the reaction mixture by filtration, the solution is concentrated by removing the solvent, preferably in vacuo, and the residue is triturated or recrystallized from water or other suitable solvent to yield crystalline (I).
The cyclic ureas (III) employed in the preparation of the bis cyclic ureas in accordance with the present invention are known compounds which are readily obtained using standard methods known in the art.
A preferred cyclic urea employed in the present invention has the formula (III a) set forth above.
Illustratively, the cyclic ureas (III) are easily obtained by the method of Ozaki et al, (J.A.C.S. 79, 4358-4360, 1957) starting with the appropriate diisocyanate (V) which is converted to the cyclic urea (III) by reaction with water.
OCN--C.sub.n H.sub.2n --NCO+H.sub.2 O→III+CO.sub.2 V
Illustrative examples of the cyclic ureas (III) used in the present invention include tetramethylene urea, pentamethylene urea, hexamethylene urea, heptamethylene urea, octamethylene urea, nonamethylene urea, decamethylene urea, undecamethylene urea, dodecamethylene urea, 5,5-dimethyltetramethylene urea, 5,6-dimethyltetramethylene urea, 5,5-dimethyl heptamethylene urea, and the like.
A preferred group of cyclic urea includes tetramethylene urea, pentamethylene urea, and hexamethylene urea.
The diacid halides (IV) employed in the practice of the present invention are defined as above and a preferred diacid halide has the formula ##STR7## wherein X is defined hereinabove.
Exemplary of the diacid halides that can be used in the present invention are succinoyl dichloride, glutaroyl dichloride, adipoyl dichloride, pimeloyl dichloride, suberoyl dichloride, azelaoyl dichloride, sebacoyl dichloride, adipoyl dibromide, azelaoyl dibromide, sebacoyl dibromide, terephthaloyl dichloride, isophthaloyl dichloride, and phthaloyl dichloride.
A preferred group of diacid halides comprises adipoyl dichloride, azelaoyl dichloride, sebacoyl dichloride, terephthaloyl dichloride, isophthaloyl dichloride, and phthaloyl dichloride.
A particularly preferred group consists of terephthaloyl dichloride, isophthaloyl dichloride, and phthaloyl dichloride.
Although the bis cyclic ureas (I) in accordance with the present invention find particular utility as masked diisocyanates in one-component polyurethane systems which will be discussed in detail hereinafter, they also serve as a convenient source for a class of novel diisocyanates having the formula (II) set forth above.
The diisocyanate (II) is obtained simply by heating the bis cyclic urea at a temperture high enough to cause its dissociation. The heating may be carried out in the absence of solvent, however, the bis cyclic ureas (I) in their most purified form are crystalline compounds and it is generally preferable to carry out the conversion in a solvent in the absence of moisture. The resulting solution of the diisocyanate (II) can then be employed in some further operation in the form of a solution, or, optionally, the solvent may be removed using standard methods known to those skilled in the art, for example, distillation, vacuum concentration, thin-film evaporation, etc., to provide the pure diisocyanate.
The conversion is advantageously carried out within a temperature range of about 100° C. to about 250° C., preferably from about 150° C. to about 180° C. for a period of time from about 5 minutes to about 5 hours and preferably from about 10 minutes to about 30 minutes.
Solvent choice is not critical and any solvent which is inert to both the bis urea (I) and diisocyanate (II) may be used in the dissociation reaction provided its boiling point is high enough to permit heating of the solution to affect the dissociation of I to II. Typical solvents include those used in the preparation of the bis cyclic ureas (I) set forth above. Advantageously, the same solvent in which the urea (I) is prepared is used for the dissociation reaction.
A preferred class of diisocyanates are those having the formula ##STR8##
These diisocyanates are obtained from the dissociation of the bis cyclic ureas having the formula (I a) set forth above.
The diisocyanates (II) embrace a novel class which includes (a) aliphatic amide containing aliphatic diisocyanates, and (b) aromatic amide containing aliphatic diisocyanates. These diisocyanates can be converted to a variety of condensation polymers using procedures well known in the art. Illustratively, they can be converted to non-cellular polyurethanes for use in elastomers, coatings, fibers, and adhesives, using procedures such as those described in Saunders et al, Polyurethanes, Chemistry and Technology, Part II, Interscience Publishers, New York, 1964. The polyurethanes so prepared are characterized by greater color stability on exposure to sunlight or ultraviolet irradiation compared with corresponding polyurethanes prepared from aromatic diisocyanates.
The bis cyclic ureas (I) find particular utility as masked diisocyanates in one-component or one-can polyurethane systems. The bis cyclic urea (I) is thoroughly blended with a polymeric polyol in essentially stoichiometric proportions at a temperature below 65° C., preferably from about 20° C. to about 65° C., using any suitable mixing procedure known to those skilled in the art, and preferably under anhydrous conditions to exclude moisture.
The resulting blend is a storage stable composition which can be stored for an indefinite period of time at a reasonable ambient temperature, for example 20°-30° C., without undergoing reaction to form polyurethane.
Upon heating said storage stable composition to a temperature in the range of about 100° C. to about 250° C., the bis cyclic urea (I) and polymeric polyol undergo reaction to form a polyurethane resin. Heating time should be sufficient to complete the reaction between the polyol and masked isocyanate and will vary according to the viscosity of the blend composition, the chemical structure of the polyol, and the presence or absence of a polyurethane catalyst, and, most importantly, temperature. Optimum conditions of time and temperature for any given system are easily determined by trial and error on small aliquot samples of the composition.
It is frequently desirable, but not essential, to include a catalyst in the reaction mixture employed to prepare the compositions of the invention. Any of the catalysts conventionally employed in the art to catalyze the reaction of an isocyanate with a reactive hydrogen containing compound can be employed for this purpose; see for example, Saunders et al., Polyurethanes, Chemistry and Technology, Part I, Interscience, New York, 1963, pages 228-232; see also Britain et al., J. Applied Polymer Science, 4, 207-211, 1960. Such catalysts include organic and inorganic acid salts of, and organometallic derivatives of, bismuth, lead, tin, iron, antimony, uranium, cadmium, cobalt, thorium, aluminum, mercury, zinc, nickel, cerium, molybdenum, vanadium, copper, manganese and zirconium, as well as phosphines and tertiary organic amines. Representative organotin catalysts are stannous octoate, stannous oleate, dibutyltin dioctoate, dibutyltin dilaurate, and the like. Representative tertiary organic amine catalysts are triethylamine, triethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetraethylethylenediamine, N,methylmorpholine, N-ethylmorpholine, N,N,N',N'-tetramethylguanidine, N,N,N',N'-tetramethyl-1,3-butanediamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, and the like. The amount of catalyst employed is generally within the range of about 0.02 to about 2.0 percent by weight based on the total weight of the reactants.
The polymeric polyols employed in the storage stable composition and defined hereinabove include any of the polyols set forth in U.S. Pat. Nos. 3,745,133 and 3,423,344 the disclosures of which are incorporated herein by reference.
It will be understood by those skilled in the art that when the polymeric polyol employed in the storage stable compositions of the invention has more than two hydroxy groups, the resulting polyurethane resin will be highly cross-linked and give rise to a solid, hard, and high modulus polyurethane resin in the absence of modifying agents. Polyurethanes produced thereby can be used particularly for potting and encapsulating electrical components.
In a preferred embodiment of the storage stable compositions in accordance with the present invention the bis cyclic ureas (I a) are blended with a mixture of a polymeric diol as defined above, and a difunctional extender, and a polyurethane catalyst. Upon heating, this composition is converted to an elastomeric polyurethane resin. The proportions of urea and diol extender combination are chosen so that the ratio of the equivalents of isocyanate arising from the urea dissociation to the total number of hydroxyl or active hydrogen groups in the polymeric diol and extender is within the range of 0.95:1 to 1.10:1 and preferably within the range of 0.98:1 to 1.04:1. Further, as will be appreciated by one skilled in the art, the proportion of polymeric diol to extender can be varied within a wide range depending largely upon the desired hardness of the final polyurethane elastomer. Advantageously, the molar proportion of polymeric diol to extender is within the range of 0.05:1 to 2:1 and, preferably, within the range of 0.1:1 to 1:1.
If desired, the elastomers of the invention can have incorporated in them, at any appropriate stage of preparation, additives such as pigments, fillers, lubricants, stabilizers, antioxidants, coloring agents, fire retardants, and the like, which are commonly used in conjunction with polyurethane elastomers.
Exemplary of the polymeric diols which can be employed in the storage stable compositions of the invention are hydroxyl terminated polyesters or polyethers. Illustrative of the polyether polyols are polyoxyalkylene glycols such as polytetramethylene glycol, the polyoxyethylene glycols prepared by the addition of ethylene oxide to water, ethylene glycol or diethylene glycol; polyoxypropylene glycols prepared ty the addition of 1,2-propylene oxide to water, propylene glycol or dipropylene glycol; mixed oxyethylene oxypropylene glycols prepared in a similar manner utilizing a mixture of ethylene oxide or propylene oxide or a sequential addition of ethylene oxide and 1,2-propylene oxide; polyether glycols prepared by reacting ethylene oxide, propylene oxide, or mixtures thereof with mono- and polynuclear dihydroxybenzene, e.g. catechol, resorcinol, hydroquinone, orcinol, 2,2-bis(p-hydroxyphenyl)propane, bis(p-hydroxyphenyl)methane and the like.
Illustrative of polyester polyols are those prepared by polymerizing ε-caprolactone using an initiator such as ethylene glycol, ethanolamine and the like, and those prepared by esterification of polycarboxylic acids such as phthalic, terephthalic, succinic, glutaric, adipic acids and the like with polyhydric alcohols such as ethylene glycol, butanediol, and the like.
The difunctional extenders which can be employed in preparing the storage stable compositions of the invention can be any of the difunctional active hydrogen containing extenders commonly employed in the art. The latter are inclusive of glycols, diamines, amino alcohols, and the like. Illustrative of diol extenders are aliphatic diols, advantageously containing from 2 to 6 carbon atoms, inclusive, such as ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,2-hexanediol, neopentyl glycol, and the like; and dihydroxyalkylated aromatic compounds such as the bis(2-hydroxyethyl)ethers of hydroquinone and resorcinol; p-xylene-α,α'-diol; the bis(2-hydroxyethyl)ether of p-xylene-α,α'-diol; m-xylene-α,α'-diol and the bis(2-hydroxyethyl)ether thereof. Illustrative of diamine extenders are aromatic diamines such as p-phenylenediamine, m-phenylenediamine, benzidine, 4,4'-methylenedianiline, 4,4'-methylenebis(2-chloroaniline) and the like. Illustrative of amino alcohols are ethanolamine, propanolamine, butanolamine, and the like.
The storage stable compositions can be used in the preparation of (i) polyurethane coatings, particularly wire coating; (ii) coatings for metals because of their high adhesion properties to metals and other surfaces due to free isocyanate generation upon heating; and (iii) sealants, gaskets, seals, and the like. Furthermore, these applications of the compositions of the invention can be conducted at elevated temperatures and do not give rise to any volatile by-product formation.
The following examples describe the manner and process of making and using the invention and set forth the best mode contemplated by the inventors of carrying out the invention but are not to be construed as limiting.
EXAMPLE 1
A 250 ml. reaction flask equipped with a mechanical stirrer, a reflux condenser, thermometer, and addition funnel was charged with 6.84 g. (0.06 mole) of tetramethylene urea, 10.1 g. (0.1 mole) of triethylamine, and 150 ml. of ethylene dichloride. The mixture was stirred to form a solution and, at room temperature (about 25° C.) and over a period of about 22 minutes, a solution of 6.09 g. (0.03 mole) of isophthaloyl chloride, dissolved in 30 ml. of ethylene dichloride, was added during constant stirring. Reaction temperature during the addition slowly rose to 42° C. and the solution became cloudy as a precipitate formed.
The reaction mixture was cooled and filtered to collect 5.95 g. of the hydrochloride salt of triethylamine. Evaporation of the filtrate provided 20.05 g. of thick liquid residue. It was triturated in excess ethyl acetate until it was crystalline then filtered. A crystalline solid was obtained, wt.=6.75 g., m.p.=185°-200° C. The crystalline solid was triturated in 100 ml. of water, filtered, washed with fresh water, and dried to yield 3 g. of crystalline N,N'-isophthaloyl bis(tetramethylene urea) which melted at 225°-230° C. This compound is a bis cyclic urea in accordance with the present invention and corresponds to the following formula ##STR9##
Using the procedure and ingredients set forth above except that either the isophthaloyl chloride is replaced by the equivalent amount of the following diacid chlorides, or else the tetramethylene urea is replaced by the equivalent amount of the following cyclic ureas, there are produced the corresponding bistetramethylene ureas and N,N'-isophthaloyl bis cyclic ureas in accordance with the present invention.
______________________________________Diacid chloride Bistetramethylene urea______________________________________Terephthaloyl chloride N,N'-Terephthaloyl bis(tetra- methylene urea)Adipoyl chloride N,N '-Adipoyl bis(tetramethylene urea)Azelaoyl chloride N,N'-Azelaoyl bis(tetramethylene urea)Sebacoyl chloride N,N'-Sebacoyl bis(tetramethylene urea)α-Methyladipoyl chloride N,N'-(α-Methyladipoyl)bis (tetramethylene urea)______________________________________Cyclic Urea Bis Cyclic Urea______________________________________Pentamethylene urea N,N'-Isophthaloyl bis(penta- methylene urea)Hexamethylene urea N,N'-Isophthaloyl bis(hexa- methylene urea)Octamethylene urea N,N'-Isophthaloyl bis(octa- methylene urea)5,5-Dimethyltetra- N,N'-Isophthaloyl bis(5,5-methylene urea dimethyltetramethylene urea)5,6-Dimethyltetra- N,N'-Isophthaloyl bis(5,6-methylene urea dimethyltetramethylene urea)______________________________________
Stability of N,N'-Isophthaloyl Bis(Tetramethylene Urea)
A 0.5 g. sample of N,N'-isophthaloyl bis(tetramethylene urea) and 25 ml. of methanol were heated for 5 hours under reflux (temperature range of 64° C.-67° C.). The mixture was cooled then filtered to obtain 0.3 g. of the starting compound, m.p.=235°-240° C. The remainder of the starting bis urea was soluble in the methanol. The N,N'-isophthaloyl bis(tetramethylene urea) was therefore characterized as stable at 65° C. since no carbamate formed upon heating in the methanol.
Dissociation of N,N'-Isophthaloyl Bis(Tetramethylene Urea) to N,N'-Di(4-Isocyanatobutyl)Isophthalamide
A 0.25 g. sample of N,N'-isophthaloyl bis(tetramethylene urea) and 10 ml. of ortho dichlorobenzene (ODCB) were placed in a 25 ml. round bottom flask equipped with a reflux condenser, stirrer and thermometer. The mixture was heated during stirring and when the solution started to reflux (at 180° C.), samples of the solution were removed and analyzed by infrared absorption spectroscopy. Isocyanate absorption at 4.34μ was evident in the first sample taken and dissociation of the diurea was complete within 30 minutes at 180° C. Thus there was obtained N,N'-di(4-isocyanatobutyl)isophthalamide in accordance with the present invention and corresponding to the formula ##STR10##
It was characterized by infrared absorption analysis including the characteristic isocyanate absorption at 4.34μ.
Using the above procedure of heating in ODCB at 180° C. the bistetramethylene ureas and bis cyclic ureas set forth below there are produced the corresponding diisocyanates in accordance with the present invention set forth below.
______________________________________Bis Urea Diisocyanate______________________________________N,N'-Terephthaloyl bis N,N'-Di(4-isocyanatobutyl)(tetramethylene urea) terephthalamideN,N'-Adipoyl bis(tetra- N,N' -Di(4-isocyanatobutyl)methylene urea) adipamideN,N'-Azelaoyl bis(tetra- N,N'-Di(4-isocyanatobutyl)methylene urea) azelamideN,N'-Sebacoyl bis(tetra- N,N'-Di(4-isocyanatobutyl)methylene urea) sebacamideN,N'-(α-Methyladipoyl)bis N,N'-Di(4-isocyanatobutyl)(tetramethylene urea) α-methyladipamideN,N'-Isophthaloyl bis(penta- N,N'-Di(5-isocyanatopentyl)methylene urea) isopthalamideN,N'-Isophthaloyl bis(hexa- N,N'-Di(6-isocyanatohexyl)methylene urea) isophthalamideN,N'-Isophthaloyl bis(octa- N,N'-Di(8-isocyanatooctyl)methylene urea) isophthalamideN,N'-Isophthaloyl bis(5,5- N,N'-Di(4-isocyanato-2,2-dimethyltetramethylene dimethylbutyl)isophthal-urea) amideN,N'-Isophthaloyl bis(5,6- N,N'-Di(4-isocyanato-2,3-dimethyltetramethylene dimethylbutyl)isophthal-urea) amide______________________________________
EXAMPLE 2
A 1.79 g. (0.005 mole) sample of N,N'-isophthaloyl bis(tetramethylene urea) and 3.31 g. (0.005 mole) of Teracol 650 (a tetramethyleneglycol, E.W.=331, supplied by E. I. DuPont Company, Wilmington, Del.) were mixed in a test tube and degassed at 100° C. under vacuum of about 0.1 mm. The reactants were not completely miscible at this temperature.
The temperature was slowly raised and at 210°-215° C. a clear homogeneous solution had formed. Heating was continued at about 220°-230° C. for 15 minutes then the hot clear solution was poured into an aluminum dish. Upon cooling, it formed a hard resilient dark yellow polymer characterized by the following recurring unit ##STR11## wherein R corresponds to the divalent residue formed by the removal of the two hydroxyl groups of Teracol 650.
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Novel bis cyclic ureas are disclosed having the formula ##STR1## wherein C n H 2 n represents alkylene from 4 to 12 inclusive and provided there are at least 4 carbon atoms in succession in the chain and R is the residue obtained by the removal of both halogen atoms from a diacid halide.
The bis cyclic ureas are easily converted to a novel class of aliphatic diisocyanates simply by heating. Alternatively, they are blended with polymeric polyols to form one-component storage stable compositions which are thermally converted to polyurethane resins without any significant volatile or side product formation.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of copending U.S. application Ser. No. 11/712,636 filed Mar. 1, 2007, which is hereby incorporated by reference in its entirety herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates, generally, to locks, and more specifically, it relates to a multi-shackle lock for locking luggage that can be subjected to inspection and then be relocked.
[0004] 2. Description of the Related Art
[0005] Combination operated padlocks of the type typically used to secure luggage during travel and transport are well known. U.S. Pat. No. 6,877,345 teaches combination operated luggage padlocks that also may be operated by a key to facilitate inspection of the contents of luggage. Specifically, the combination and key operated luggage padlocks and the like have a resettable indicator to advise the owner of the luggage that a lock on the bag has been opened presumably by a key for inspection. The opened luggage indicator preferably can be reset only by the owner after he/she has opened the lock by entering a respective combination.
[0006] When the U.S. Transportation Security Administration (TSA) took over the handling of airport security in accordance with the Homeland Security Act, the intensified effort made by federal employees to inspect locked bags of airline passengers often resulted in the destruction of luggage padlocks when the shackles thereof were severed to permit inspection of the luggage contents. The destruction of luggage padlocks unfortunately leaves inspected bags unlocked, with their contents subject to pilfer and theft during travel and transport.
[0007] The need of travelers for post-inspection luggage security while also accommodating the need of government employees to quickly and easily open and inspect selected and suspect bags, lead to the development of override keys for nondestructively opening the luggage.
[0008] Combination operated luggage padlocks that have built-in key override features were now introduced. Such padlocks may be purchased by consumers for locking their luggage; and, if their locked bags are inspected by government personnel, the padlocks will be opened for baggage inspection using keys that are made available to government inspectors (but not to the owners of the padlocks), and then will be relocked by the inspectors. Bags inspected and relocked in this manner will have their contents secured by the same combination operated padlocks that were installed on the bags by the owners thereof.
[0009] Padlocks that can be operated by combination and by key are not new. Combination padlocks have been used for many years on gym lockers in schools, with coaches and principals having keys that can open these padlocks should lockers need to be inspected, or should a padlock be snapped closed on an incorrect locker by mistake or by prank. It also is known to provide combination padlocks with keys so that their owners may elect whether to open the locks by entry of a combination, or by using a key. It is not completely new to provide padlocks with some form of indicator. For example, padlocks that are not of the type that can be opened both by combination and by key have been provided with indicators that are intended to prevent accidental resetting of the combinations of the locks, or that are intended to reflect when the padlocks are incompletely or improperly relocked after being opened. However, prior proposals relating to padlocks of the type that can be opened by combination or by key have not taught or suggested the provision of indicators constructed to advise the owners of the locks that the luggage on which the padlocks are installed has been inspected by opening the padlocks with a key.
SUMMARY OF THE INVENTION
[0010] It is accordingly an object of the invention to provide a multi-shackle lock and method of using the multi-shackle lock, which overcomes the herein-mentioned disadvantages of the heretofore-known devices and methods of this general type, which allows the lock to be opened and relocked without the need of a special key.
[0011] With the foregoing and other objects in view there is provided, in accordance with the invention, a lock. The lock is formed of a housing, a locking mechanism supported by the housing, and three shackles being lockable by the locking mechanism or the housing.
[0012] As noted above, after Sep. 11, 2001 the Transportation Security Administration (TSA) took over the handling of airport security and inspection of luggage. In order to inspect the luggage, the baggage locks had to be cut and the luggage was left unsecured as it traveled throughout the transportation system. TSA then requested that customers not lock their luggage in order to allow inspection without damaging the luggage and the locks.
[0013] In an attempt to provide the customers a way of securing their bags while still allowing TSA to carry out their inspection, several companies configured locks with both a key lock and a combination lock and many of these locks have an indicator for identifying if the lock was opened for inspection. Special master keys were then given to the TSA for opening all the locks.
[0014] However, these prior art locks simply do not provide the security they advertise. It is a false sense of security for the following few and simple reasons. There are thousands of TSA agents throughout our country, all of which have access to the keys that open the locks. It is only a matter of time, if it has not already occurred that these keys will fall into the hands of what we call the luggage bandit. In many cases the locks have the second key operation option but have no measure for letting the customer know that someone has opened the lock. This is equivalent to having a home alarm system and giving a second alarm security code to thousands of people you do not know. The second reason is that 90% of all luggage used today is of the zipper closure type. On this type of luggage you can simply pull the zipper closure with the locked lock to one extreme of the luggage zipper. Using a sharp object as simple as a ball point pen you can open the zipper and pilfer the luggage. Once finished you can simply pull the closed lock and secured zipper closure to the opposite extreme. This re-zips and closes the zipper 99%. To the untrained eye the luggage shows no signs of having been tampered with until you have arrived to your home or vacation destination. In addition the above-mentioned keys are only available to USA agents and are not available on an international level. Therefore, when traveling internationally, the current so called TSA luggage locks will be cut as before and the luggage will be left unsecured throughout the rest of its journey.
[0015] In accordance with an added feature of the invention, the housing includes a main housing and a shackle housing releasably holding one of the three shackles for replacing the one shackle. The main housing houses the locking mechanism and the shackle housing supports two of the three shackles. The shackle housing is releasably connected to the main housing for replacing the shackle housing containing the two shackles with a new shackle housing contain two new shackles.
[0016] In accordance with another feature of the invention, the three shackles include a luggage securing shackle made from metal, plastic, cabling, wiring or a combination of at least two of metal, cabling and wiring.
[0017] Ideally, the housing has a serial number for at least one of identification, tracking, travel insurance and travel assistance service. Alternatively or additionally, a tracking device is supported by the housing and the lock can be tracked world wide.
[0018] In a further embodiment of the invention, each of the three shackles may be color coded for identifying the shackle function. The three shackles include a first shackle locked in place by the locking mechanism, a second shackle locked in place by the locking mechanism, and a third shackle locked in place by the locking mechanism or locking to the shackle housing. Preferably, the second shackle is releasable secured to the shackle housing, and the third shackle is permanently fixed to the shackle housing.
[0019] In accordance with another feature of the invention, the shackle housing has a locking key for releasably securing the shackle housing to the main housing. The main housing has a housing side wall with a recess formed therein, and the locking key can be inserted through the recess and held in place by the housing side wall. The shackle housing is rotatable about the locking key for replacing the second shackle. The shackle housing has a wall and the locking key has a cutout formed therein next to the wall for fixing around the housing side wall. In accordance with another feature of the invention, the main housing and the shackle housing define a recess therebetween. The shackle housing has an abutment extending out from the recess, and the third shackle secures to the abutment when inserted in the recess. Uniquely, the third shackle is released from the abutment when the shackle housing is rotated.
[0020] With the foregoing and other objects in view there is further provided, in accordance with the invention, a method of operating a luggage lock. The method includes providing a multi-shackle lock having a main housing, a shackle housing, and two or more, ideally three shackles, including a first shackle, a second shackle and a third or additional shackle. The first shackle is secured to an anchor part of a piece of luggage having a zipper. The second shackle is secured to a zipper pull-tab for preventing an opening of the piece of luggage. The third shackle is left unlocked.
[0021] In accordance with a further mode of the invention, the second shackle is cut resulting in a cut second shackle. The piece of luggage is opened for inspection and then relocked by securing the third shackle to the zipper pull tab. After this, the cut second shackle is removed and a new second shackle is inserted putting the lock back to a as new condition.
[0022] Alternatively, the shackle housing containing the cut second shackle and the third shackle is removed from the main housing and a new shackle housing containing a new second shackle and a new third shackle is reconnected to the main housing.
[0023] In order to perform the replacement, the shackle housing is rotated about the main housing for getting access to the cut second shackle. The cut second shackle is removed and the new second shackle is inserted. The shackle housing is rotated back and the shackle housing is secured in place by inserting the new second shackle into the main housing.
[0024] An alternate and preferred embodiment of the invention is a multi-shackle lock which is formed of a main housing which houses two or more shackles, a locking mechanism to close and secure the shackles and a method of releasing any of the shackles for the purpose of replacing them in the event they are cut or their integrity has been compromised.
[0025] The lock housing may have but is not limited to a button or push pin type of mechanism that is used to release any of the shackles for the purpose of replacing them after they have been cut or their integrity has been compromised. The button or release mechanism can only be operated when the lock is placed in the open position by setting the lock to a preset combination, by opening the lock with a key or any combination thereof.
[0026] It is the intent of the invention that only the customer is able to open the lock with a combination or key and that only after the lock has been opened can the broken shackles be released by a button or mechanism which allows the owner of the lock to replace the shackle or shackles.
[0027] With the foregoing and other objects in view there is further provided, in accordance with the invention, a second embodiment of the lock. This lock contains a housing, a locking mechanism supported by the housing, and a first shackle releasably locked by the locking mechanism to allow the first shackle to be replaced. A button is provided and is supported by the housing for locking or releasing one end of the first shackle.
[0028] In accordance with an added feature of the invention, a second shackle is releasably locked by the locking mechanism to allow the second shackle to be replaced. In addition, a third shackle is releasably locked by the locking mechanism to allow the third shackle to be replaced, the third shackle is disposed on an end opposite the first and second shackles.
[0029] In accordance with another feature of the invention, the button releases or locks one end of the first and second shackles.
[0030] In accordance with a further feature of the invention, a seat is provided for supporting the locking mechanism, and a locking plate is pivotably mounted in the seat pivotable between a first position and a second position in dependence on the locking mechanism. If the locking plate is in the first position, the shackle is locked in place, and if the locking plate is in the second position, the shackle is removable from the lock.
[0031] The button has a locking trigger engaging the shackle in a locked position when the locking plate is in the first position. The button is actuable when the locking plate is in the second position. Upon actuation of the button, the locking trigger expels one end of the shackle from the housing.
[0032] In accordance with another added feature of the invention, a shaft supports the locking mechanism. A lever is provided that has a recess for receiving and locking in place a second end of the shackle. When the locking plate is in the first position, the locking plate prevents movement of the lever. When the locking plate is in the second position, the lever is movable for releasing the shackle from the housing.
[0033] In accordance with a concomitant feature of the second embodiment of the invention, a locking gate is provided for securing both ends of the third shackle. When the locking plate is in the second position, the locking gate is moveable against the shaft, pushing in the shaft, and releasing both ends of the third shackle for removing the third shackle from the lock.
[0034] Other characteristic features of the invention are set forth in the appended claims.
[0035] Although the invention is illustrated and described herein as embodied in a multi-shackle lock and a method of using the multi-shackle lock, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0036] The construction of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is a diagrammatic, perspective view of a first embodiment of the multi-shackle lock according to the invention;
[0038] FIG. 2 is a diagrammatic, exploded perspective view of the first embodiment of the multi-shackle lock;
[0039] FIG. 3 is a diagrammatic, top plan view of a shackle housing the first embodiment;
[0040] FIG. 4 is a perspective view of the first embodiment of the multi-shackle lock with a top cover removed;
[0041] FIG. 5 is a perspective view of the first embodiment of the multi-shackle lock with a shackle housing in a rotated position and a bottom cover removed;
[0042] FIG. 6 is a diagrammatic, longitudinal view of the shackle housing showing only the openings for a second shackle of the first embodiment;
[0043] FIG. 7 is a diagrammatic, perspective view of a second embodiment of the multi-shackle lock according to the invention;
[0044] FIG. 8 is an exploded, perspective view of the second embodiment of the multi-shackle lock;
[0045] FIG. 9 is perspective view of the second embodiment of the multi-shackle lock with the cover removed;
[0046] FIG. 10 is a side elevational view of the second embodiment of the multi-shackle lock with the cover removed;
[0047] FIG. 11 is a diagrammatic, left-side plan view of the second embodiment of the multi-shackle lock with the shackles removed; and
[0048] FIG. 12 is a diagrammatic, right-side plan view of the second embodiment of the multi-shackle lock with the shackles removed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0049] Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a first embodiment of a lock 20 being a combination operated lock, a key operated lock or both a combination and key operated lock 20 all with a multi-shackle locking system.
[0050] The multi-shackle lock 20 can be operated by a preset combination, a key, or both the preset combination and the key. The operation of the lock 20 is similar to locks currently on the market for use on luggage, sport bags or equipment cases. In FIG. 1 , the lock 20 is provided with a single combination lock mechanism 2 having three combination thumb wheels 4 for operating the combination lock mechanism 2 . Of course the number of thumb wheels 4 can vary between 2-6. A single key lock or two locks being a key and combination lock are also possible, however FIG. 1 only shows a single combination lock 2 without the need for a key.
[0051] As best shown in FIG. 2 , the multi-shackle lock 20 has a housing formed of two connectable housing parts 8 , 12 and a removable shackle housing 9 .
[0052] The lock 20 features a unique multi-shackle system that allows the lock 20 to be secured to a piece of luggage, more particularly to a luggage handle. What is further specific and unique about the lock 20 is that it can only be operated by the owner of the lock 20 because only the single combination lock mechanism 2 is present. However, the lock 20 still allows TSA and all international security agents to inspect the luggage and return it to a locked condition by providing additional unlocked shackles. A first shackle 7 is used to secure the lock 20 to a luggage handle or similar anchor part on a piece of luggage. The use of the luggage handle eliminates the possibility of moving the lock 20 to the zipper extreme, opening the luggage and using the closed lock to reseal the zipper. A second shackle 10 is used by the owner to close or secure the luggage opening, e.g. lock the zipper tab (slider) to the luggage handle. A third shackle 11 is left in the open position so that security agents can cut open the lock (e.g. the second shackle 10 ) as they have done for many years and re-close the lock 20 using the third shackle 11 after the luggage has been inspected.
[0053] The multi-shackle lock 20 further has the capability of replacing the shackle housing 9 . The shackle housing 9 with the second and third shackles 10 , 11 is supplied as a disposable part. Once the second shackle 10 has been cut by TSA, the owner can open the lock 20 , replace the shackle housing 9 containing new second and third shackles 10 , 11 and return the lock 20 to an as new condition. The shackle housing 9 has a locking key 21 for engaging on an inside wall 22 of the upper and lower housings 8 , 12 . The locking key 21 is initially positioned at a 90 degrees angle so that the locking key 21 slides through a recesses 23 . As the shackle housing 9 is rotated from the 90 degrees angle back to the normal, the locking key 21 engages the inside wall 22 and secures the shackle housing 9 . As best seen in FIG. 3 , there is a space 24 between the locking key 21 and a wall of the shackle housing 9 for allowing the connection between the shackle housing 9 and the upper and lower housing parts 8 , 12 .
[0054] The second shackle 10 has a notch 17 for engaging into a locking projection 18 of the combination lock mechanism 2 . When the locking projection 18 engages in the notch 17 of the second shackle 10 , the second shackle 10 secures the shackle housing 9 to the lock housing 8 , 12 , see FIG. 4 . When the second shackle 10 is cut the, the second shackle 10 can be removed. After the second shackle is removed, the shackle housing 9 can be rotated and physically pulled out from the housing 8 , 12 because the locking key 21 can now slip out of the recess 23 . In this way the whole shackle housing 9 can be rotated, removed and then replaced as described above. FIG. 5 shows the shackle housing 9 in a rotated position for removal or insertion.
[0055] Alternatively, the shackle housing 9 need only be partially rotated in which access to a first hole 25 is provided. As noted, the shackle housing 9 is partially rotated, the cut second shackle 10 is removed and a replacement shackle 10 is threaded through the first hole 25 and the shackle housing 9 is closed again.
[0056] At this point it needs to be emphasized that when replacing either the shackle housing 9 or the second shackle 10 , the housing parts 8 , 12 remain secured to each other at all times and are not separated from each other as shown in the figures.
[0057] FIG. 6 shows a top, sectional view of the shackle housing 9 showing only the openings for the second shackle 10 . The second shackle 10 has a winged end 26 for fitting in a recess 27 at the end of the first hole 25 and therefore securing the second shackle 10 to the shackle housing 9 . The second shackle 10 has a mid-section 29 formed from wiring or cabling and is bent around and reinserted into a second hole 28 . In this manner, a supply of second shackles 10 is sold with the lock for multiple reuses.
[0058] Returning to FIG. 2 , a first end 30 of the third shackle 11 is fixedly secured in a third hole 31 of the shackle housing 9 . A second end 34 of the third shackle 11 has a notch 32 (see FIG. 5 ) for locking with an abutment 33 (see FIG. 2 ) when the second end 34 is inserted into recess 35 formed between the top cover 8 and the shackle housing 9 . Of course the locking mechanism can be reversed with an abutment formed on the second end 34 of the third shackle 11 for latching with a cutout formed in the recess 35 . As can best be seen in FIG. 5 , when the shackle housing 9 is rotated, the second end 34 of the third shackle 11 is automatically released and ready for reuse.
[0059] The multi-shackle lock 20 addresses all the fore mentioned issues relating to the prior art locks alone or the locks with a special TSA key. By securing the lock 20 to the luggage or luggage handle you eliminate the possibility of having the lock being used to reseal the zipper. With this method the zipper can't be re-closed and therefore will most likely never be opened. By providing the additional shackles 10 , 11 the customer can lock his\her luggage and use it both nationally and internationally. The customer simply locks the luggage, the international agent simply cuts it open for inspection and re-locks it with the additional shackle.
[0060] Ideally, the locks will all be the same colors, such as a bright orange with separate colors to identify the different shackle of the system. Therefore the lock of the instant application requires no intervention or cooperation with TSA or other agencies (e.g. send them master keys).
[0061] In addition the multi-shackle lock 20 may be provided with additional security features such as a serial number 15 or tracking bar code and/or tracking device 16 . The tracking device 16 may be an active or passive radio frequency identifier (RFID), a global positioning satellite (GPS) reader or other electronic/visual tracking device.
[0062] In this manner, a luggage tracking service and a travel assistance service can be easily incorporated or used with the lock. Ideally, the information relating to the location of the lock 20 can be provided on a web site under each specific customer account. The customer logs on to our web sit using his or her user name and password. The site shows a page that displays all the locks owned by that specific customer and where they are. In addition, the website allows reorders for new shackles.
[0063] As noted above, the multi-shackle lock can be used universally (e.g. internationally) where any airport inspection agency can use the lock and at the same time, the owner will know that his luggage has been inspected.
[0064] FIGS. 7-12 show a second embodiment of a multi-shackle lock 50 also having three shackles 51 - 53 . It is noted here that the second embodiment can function with 1, 2 or 3 shackles as the shackles are all independently and readily replaceable. In other words, a replaceable single shackle lock or a two-shackle lock is possible in addition to the three-shackle lock that is shown. As in the first embodiment, the second embodiment has a locking mechanism 55 for securing the shackles. However, the second embodiment has a release button 56 that is used in combination with the lock 55 for securing and releasing the shackles 52 - 53 .
[0065] A front housing part 60 and a back housing part 61 house the lock 55 and the release button 56 . As shown best in FIG. 8 , the locking mechanism 55 is mounted in a seat 57 via a shaft 58 and respective openings 59 and 60 in the seat 57 for receiving the shaft 58 . The seat 57 has a locking plate 61 which is spring biased to an upward position by non-illustrated springs disposed below the locking plate 61 towards the rear of the seat 57 . When the combination of the locking mechanism 55 is correct, the locking plate 61 pivots up as shown by arrow 62 . When the combination of the locking mechanism 55 is incorrect the locking plate 61 is kept pushed down, see arrow 62 . When the locking plate 61 is pushed down, it blocks the movement of the release button 56 and therefore the shackles 52 - 53 cannot be removed. The operation of such a locking mechanism 55 for moving a locking plate is known from U.S. Pat. No. 5,746,075 which is hereby incorporated by reference herein.
[0066] As shown in FIG. 8 , two locking triggers 70 hold first ends 69 of the shackles 52 , 53 in place. As seen in FIG. 10 , the shackles 52 , 53 have grooves 71 engaged by the locking triggers 70 holding the shackles 52 , 53 in a locked position. The release button 56 has a first arm 72 . When the combination of the locking mechanism 55 is correct, the release button 56 can be pushed in or actuated because the locking plate 61 no longer obstructs movement of the release button 56 . When the release button 56 is pushed in, the first arm 72 travels in a direction of arrow 73 ( FIG. 10 ) and pushes the locking triggers 70 out of engagement of the grooves 71 of the shackles 52 , 53 and the shackles 52 , 53 are thereby no longer locked in place. The ends 69 of the shackles 52 , 53 pop out of the lock 50 because the triggers 70 are spring biased by springs 75 that push the shackles out when the triggers 70 are moved out of their locking position.
[0067] Second ends 80 of the shackles 52 , 53 are held in place by lever 76 . When the combination of the locking mechanism 55 is correct, the locking plate 61 moves up and out of the way of locking arm 77 of the lever 76 . In this manner, the lever 76 can be pushed in and the second ends 80 of the shackles 52 , 53 can be removed from the lock 50 . The lever 76 is spring biased by a spring 79 to push the lever 76 into the shackles 52 , 53 for securing the shackles 52 , 53 in place.
[0068] FIG. 11 shows a side view of the housing 60 , 61 with recesses 85 and 86 . The first ends 69 of the shackles 52 , 53 are pressed into the recesses 85 . The second ends of the shackles 80 are pressed in the recess 86 and slide into the associated slots 87 for securement into a recess 78 ( FIG. 10 ) formed in the lever 76 . The recess 78 is defined by a shoulder preventing the movement of the shackle 53 out of the lever 76 unless the lever 76 is first pushed in.
[0069] The shackle 51 is also releasably held in the housing 60 , 61 in a similar fashion. Both ends of the shackle 51 are held in a locking gate 90 . More specifically, as shown in FIGS. 12 and 10 , ends 93 of the shackle 51 are entered into a central recess 92 , one at a time and slide along the slides 91 into a locked position to the sides of the central recess 92 and held by the locking gate 90 . When the combination of the locking mechanism 55 is not proper the shaft 58 is locked in place blocking any movement of the locking gate 90 . When the combination of the locking mechanism 55 is proper, the shaft 58 can be pushed in the direction of arrow 94 shown in FIG. 10 and the ends 93 of the shackle can be moved from the slot 91 to the recess 92 and removed. The shaft 58 is spring biased by spring 63 towards the locking gate 90 . When the combination is correct, the user pushes in the shackle 51 , which in turn pushes in the gate 90 . More specifically, the gate 90 has an abutment 95 that pushes against the shaft 58 counter to the spring 63 . The shaft 58 and the locking gate 90 move in the direction of the arrow 94 allowing the shackle 51 to be pulled out via the slide and recess 91 , 92 . The shaft 58 has a protrusion 95 that is disposed in a recess formed in the locking plate 61 . When the locking plate 61 is in the raised position, the shaft 58 can be moved when pushed by the locking gate 90 . In the lowered position, the locking plate 61 blocks the movement of the protrusion 95 and thus the movement of the shaft 58 and therefore locks the shackle 51 in place. The protrusion 95 has a narrow area and a thickened area. The thickened area hits the locking plate 61 when the locking plate 61 is in the lowered position. The narrow area allows movement towards the locking plate 61 when the locking plate 61 is in the raised position.
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A lock for luggage, sports gear or any type of travel enclosure which can be operated by a key, combination or both, which has at least one removable shackle. The lock has one shackle that secures the lock to the luggage or luggage handle while the other shackle secures the luggage closure or zipper. An addition shackle is provided for the purpose of re-closing the luggage after the luggage is inspected by an international airport security agent. If the luggage is inspected, the inspector simply cuts the zipper shackle and re-secures the luggage using the additional or third shackle. A disposable shackle system allows the customer to replace the cut shackle and return the lock to its original condition for reuse.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to expandable endoprosthesis devices, generally known as stents, which are designed for implantation in a patient's body lumen, such as arteries or blood vessels to maintain the patency thereof. These devices are particularly useful in the treatment and repair of blood vessels after a stenosis has been compressed by percutaneous transluminal coronary angioplasty (PTCA), or percutaneous transluminal angioplasty (PTA), or removed by atherectomy or other means.
[0002] Stents are generally cylindrically-shaped devices which function to hold open and sometimes expand a segment of a blood vessel or other lumen such as a coronary artery.
[0003] A variety of devices are known in the art for use as stents and have included balloon expandable stents having a variety of patterns; coiled wires in a variety of patterns that are expanded after being placed intraluminally on a balloon catheter; helically wound coiled springs manufactured from an expandable heat sensitive metal; and self expanding stents inserted in a compressed state and shaped in a zigzag pattern. One of the difficulties encountered using prior stents involved maintaining the radial rigidity needed to hold open a body lumen while at the same time maintaining the longitudinal flexibility of the stent to facilitate its delivery and accommodate the often tortuous path of the body lumen.
[0004] Another problem area has been the limiting range of expandability. Certain prior art stents expand only to a limited degree due to the uneven stresses created upon the stents during radial expansion. This necessitates providing stents with a variety of diameters, thus increasing the cost of manufacture. Additionally, having a stent with a wider range of expandability allows the physician to redilate the stent if the original vessel size was miscalculated.
[0005] Another problem with the prior art stents has been contraction of the stent along its longitudinal axis upon radial expansion of the stent. This can cause placement problems within the artery during expansion.
[0006] Various means have been described to deliver and implant stents. One method frequently described for delivering a stent to a desired intraluminal location includes mounting the expandable stent on an expandable member, such as a balloon, provided on the distal end of an intravascular catheter, advancing the catheter to the desired location within the patient's body lumen, inflating the balloon on the catheter to expand the stent into a permanent expanded condition and then deflating the balloon and removing the catheter.
[0007] What has been needed is a stent which has an enhanced degree of flexibility so that it can be readily advanced through tortuous passageways and radially expanded over a wider range of diameters with minimal longitudinal contraction. The expanded stent must also of course have adequate structural strength (hoop strength) to hold open the body lumen in which it is expanded. The present invention satisfies these needs.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to stents having a high degree of flexibility along their longitudinal axis to facilitate delivery through tortuous body lumens, but which remain highly stable when expanded radially, to maintain the patency of a body lumen such as an artery or other vessel when implanted therein. The unique patterns and materials of the stents of the instant invention permit both greater longitudinal flexibility and enhanced radial expandability and stability compared to prior art stents.
[0009] Each of the different embodiments of stents of the present invention include a plurality of adjacent cylindrical rings which are generally expandable in the radial direction and arranged in alignment along a longitudinal stent axis. At least one link extends between adjacent cylindrical rings and connects them to one another. The rings and links may each be formed with a variety of undulations containing a plurality of alternating peaks and valleys. This configuration helps to ensure minimal longitudinal contraction during radial expansion of the stent in the body lumen. The undulations of the rings and links contain varying degrees of curvature in regions of the peaks and valleys and are adapted so that the radial expansion of the cylindrical rings are generally uniform around their circumferences during expansion of the stents from their contracted conditions to their expanded conditions.
[0010] The resulting stent structures are a series of radially expandable cylindrical rings which are spaced longitudinally close enough so that small dissections in the wall of a body lumen may be pressed back into position against the luminal wall, but not so close as to compromise the longitudinal flexibility of the stent both when being negotiated through the body lumens in their unexpanded state and when expanded into position. Upon expansion, each of the individual cylindrical rings may rotate slightly relative to their adjacent cylindrical rings without significant deformation, cumulatively providing stents which are flexible along their length and about their longitudinal axis, but which are still very stable in the radial direction in order to resist collapse after expansion.
[0011] The presently preferred structures for the expandable cylindrical rings which form the stents of the present invention generally have a plurality of circumferential undulations containing a plurality of alternating peaks and valleys where the rings are formed from a metallic material. The links interconnecting the rings may also have undulations and may be formed from a polymer or metal as well as being coated with a polymeric coating. In all embodiments, the series of links provide the stent with longitudinal and flexural flexibility while maintaining sufficient column strength to space the cylindrical rings along the longitudinal axis. The metallic material forming the rings provides the stent with the necessary radial stiffness after the stent is implanted into a body lumen.
[0012] In the case of a balloon expandable catheter system, the cylindrical rings and the links remain closely coupled from the time the stent is crimped onto the delivery system to the time the stent is expanded and implanted into a body lumen. Accordingly, the cylindrical rings have first delivery diameters in the crimped state of the stent and second larger implanted diameters in the expanded state of the stent.
[0013] The stent can generally be divided into three sections for illustration purposes. The sections include a proximal stent section, a center stent section and a distal stent section. The proximal stent section includes one proximal ring and a series of corresponding proximal links. The proximal links are attached to an adjacent center ring located in the center stent section. The center stent section includes a series of center rings along with a series of center links interconnecting the center rings. The distal stent section includes a distal ring and a series of distal links connected thereto. The distal links are also attached to an adjacent center ring in the center stent section.
[0014] The rings are each formed with circumferential undulations that may be described as a series of peaks, valleys and straight portions. For further clarification, each ring within the stent can be divided into three sections including a proximal ring section, a center ring section and a distal ring section. The proximal ring section includes the peaks while the distal ring section includes the valleys. In between the two sections the center ring section includes the straight portions.
[0015] The rings are aligned along the longitudinal axis and in the majority of embodiments arranged so that adjacent rings have peaks aligned with valleys. In this arrangement all adjacent rings are circumferentially offset from each other (out of phase) along the longitudinal axis of the stent so that they appear to be mirror images of each other. For example, the proximal ring forms the proximal end of the stent and includes valleys in its distal ring section. Adjacent the proximal ring is a center ring which is connected to the proximal rings with a series of proximal links as mentioned above. The proximal ring section of this center ring includes peaks which are aligned with the valleys of the proximal ring. Accordingly, the valleys of this center ring are aligned with the peaks of the adjacent center ring and so on for the length of the stent. In one embodiment mentioned below adjacent rings are out of phase to a lesser degree such that two rings separate completely out of phase rings.
[0016] The links interconnecting the adjacent rings may include straight portions and/or undulations. In all cases each link has a proximal link end and a distal link end. The proximal link end is attached to a distal section of one ring while the distal link end is attached to a proximal section of another adjacent ring.
[0017] In one embodiment, four links interconnect each pair of adjacent rings within the distal stent section and the proximal stent section while five links interconnect adjacent rings in the center stent section. Of these links, two (three in center section) are substantially straight and the remaining two links are more flexible with loop shapes and smaller cross-sectional areas. The two types of links are alternately arranged around the circumference of the stent so that the rigidity provided by the straight links is sufficiently offset by the flexibility provided by the loop-shaped links. The rings each include ten peaks and ten valleys and the loop-shaped rings between adjacent rings helps to prevent clamshell opening. Clamshell opening occurs when a stent is expanded and a portion of the stent between two adjacent rings separates abnormally. This abnormal operation may cause undesirable effects such as tissue prolapse, movement of the stent within a vessel and reduced coverage area.
[0018] In another embodiment three links interconnect each pair of adjacent rings rather than four and five links as discussed in the embodiment above. The rings also have nine peaks rather than ten as above. In this configuration, the links essentially couple every third undulation between adjacent rings. The links are all formed substantially straight rather than loop-shaped. The use of three links for every pair of adjacent rings provides uniform flexibility around the circumference of the stent.
[0019] In another embodiment adjacent rings are circumferentially offset with respect to each other along the longitudinal axis. The rings each have nine peaks and are offset such that two rings separate completely out of phase rings. Three links couple each pair of adjacent rings to reduce potential clamshell opening.
[0020] In another embodiment the rings each have ten peaks and adjacent rings are coupled by three links in the center stent section. The rings within the proximal stent section include undulations that, while being generally U-shaped, have curvatures incorporated therein to help retain the stent onto a delivery catheter. In the distal stent section and proximal stent section two rather than three links couple the rings to the center rings of the center stent section.
[0021] In all embodiments the rings and links may include reservoirs to retain therapeutic drugs. The reservoirs may be formed as either micro-channels or micro-depots within the rings or links. The material of the rings or links associated with these reservoirs may be either a polymer or a metal.
[0022] Each of the embodiments of the invention can be readily delivered to the desired luminal location by mounting them on an expandable member of a delivery catheter, for example a balloon, and passing the catheter-stent assembly through the body lumen to the implantation site. A variety of means for securing the stents to the expandable member on the catheter for delivery to the desired location are available. It is presently preferred to crimp the stent onto the unexpanded balloon. Other means to secure the stent to the balloon include providing ridges or collars on the inflatable member to restrain lateral movement, using bioabsorbable temporary adhesives, or a retractable sheath to cover the stent during delivery through a body lumen.
[0023] While the cylindrical rings and links incorporated into the stent are generally not separate structures when both are formed from a metallic material, they have been conveniently referred to as rings and links for ease of identification. Further, the cylindrical rings can be thought of as comprising a series of U-shaped structures in a repeating pattern. While the cylindrical rings are not divided up or segmented into U-shaped structures, the pattern of cylindrical rings resemble such configuration. The U-shaped structures promote flexibility in the stent primarily by flexing and may tip radially outwardly as the stent is delivered through a tortuous vessel.
[0024] The links which interconnect adjacent cylindrical rings can have cross-sections smaller, larger or similar to the cross-sections of the undulating components of the cylindrical rings. The links may be formed in a unitary structure with the expandable cylindrical rings, or they may be formed independently and mechanically secured between the expandable cylindrical rings. The links may be formed substantially linearly or with a plurality of undulations.
[0025] Preferably, the number, shape and location of the links can be varied in order to develop the desired coverage area and longitudinal flexibility. These properties are important to minimize alteration of the natural physiology of the body lumen into which the stent is implanted and to maintain the compliance of the body lumen which is internally supported by the stent. Generally, the greater the longitudinal flexibility of the stents, the easier and the more safely they can be delivered to the implantation site, especially where the implantation site is on a curved section of a body lumen, such as a coronary artery or a peripheral blood vessel, and especially saphenous veins and larger vessels.
[0026] The stent may be formed from a tube by laser cutting the pattern of cylindrical rings and links in the tube, by individually forming wire rings and laser welding them together, and by laser cutting a flat metal sheet in the pattern of the cylindrical rings and links and then rolling the pattern into the shape of the tubular stent and providing a longitudinal weld to form the stent.
[0027] Other features and advantages of the present invention will become more apparent from the following detailed description of the invention, when taken in conjunction with the accompanying exemplary drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is an elevational view, partially in section, of a stent embodying features of the invention which is mounted on a delivery catheter and disposed within a damaged artery.
[0029] FIG. 2 is an elevational view, partially in section, similar to that shown in FIG. 1 wherein the stent is expanded within a damaged or diseased artery.
[0030] FIG. 3 is an elevational view, partially in section, depicting the expanded stent within the artery after withdrawal of the delivery catheter.
[0031] FIG. 4 is a perspective view of the stent of FIG. 3 in its expanded state depicting the undulating pattern along the peaks and valleys that form the cylindrical rings.
[0032] FIG. 5 is a plan view of a flattened section of the embodiment shown in FIGS. 1-4 .
[0033] FIG. 6 is a plan view of a flattened section of one embodiment of a stent of the invention incorporating nine peaks within each ring.
[0034] FIG. 7 is a plan view of a flattened section of one embodiment of a stent of the invention incorporating circumferentially offset rings.
[0035] FIG. 8 is a plan view of a flattened section of one embodiment of a stent of the invention incorporating a modified U-shaped undulating ring within the proximal stent section.
[0036] FIG. 8A is a cross-sectional view of a curved portion of the proximal rings shown in FIG. 8 .
[0037] FIG. 9 is a plan view of a flattened section of one embodiment of a stent of the invention incorporating rings with micro-depots and micro-channels.
[0038] FIG. 10 is a plan view of a flattened section of one embodiment of a stent of the invention incorporating links with micro-depots and micro-channels.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] Before describing in detail an exemplary embodiment of a stent in accordance with the present invention, it is instructive to briefly describe a typical stent implantation procedure and the vascular conditions which are typically treated with stents. Referring now to FIG. 1 , a stent 10 of the present invention is shown mounted on a catheter 11 having a lumen 19 and an inflation member (balloon) 14 . The stent and catheter are shown inside the lumen of an arterial vessel 16 . The stent is shown positioned across a small amount of arterial plaque 15 adhering to the lumen of the artery. In some procedures, a stent is directly implanted without a prior procedure, such as balloon angioplasties. In other procedures, the plaque is the remainder of an arterial lesion which has been previously dilated or radially compressed against the walls of the artery, or has been partially removed from the artery. Lesion dilation is typically accomplished by an angioplasty procedure, while lesion removal is typically accomplished by an atherectomy procedure. These and other procedures for the treatment of arterial lesions are well known to those skilled in the art.
[0040] With most lesion treatment procedures, the treated artery suffers a degree of trauma, and in a certain percentage of cases may abruptly collapse or may slowly narrow over a period of time due to neointimal hyperplasia which is referred to as restenosis. To prevent either of these conditions, the treated artery is often fitted with a prosthetic device, such as the stent 10 of the present invention. The stent provides radial support for the treated vessel and thereby prevents collapse of the vessel 16 , and further provides scaffolding to prevent plaque prolapse within the lumen. The stent may also be used to repair an arterial dissection, or an intimal flap, both of which are sometimes found in the coronary arteries, peripheral arteries and other vessels. In order to perform its function, the stent must be accurately placed across the lesion site. Therefore, it is critical that the stent be sufficiently radiopaque so that the physician can visually locate the stent under fluoroscopy during the implantation procedure. However, it is equally important that the stent not be too radiopaque. If the stent is overly radiopaque, i.e., too bright, the physician's view of the lumen is compromised. This makes assessment of subsequent restenosis difficult. In cases where balloon markers are very close to the stent, the stent can blend in with the markers. Without precise visualization of the stent ends, accurate placement of the stent in a lesion, particularly in the case of an ostial lesion, can be compromised.
[0041] With continued reference to FIG. 1 , in a typical stent placement procedure, a guiding catheter (not shown) is percutaneously introduced into the cardiovascular system of a patient through the femoral arteries by means of a conventional Seldinger technique, and advanced within a patient's vascular system until the distal end of the guiding catheter is positioned at a point proximal to the lesion site. A guide wire and the stent-delivery catheter 11 of the rapid exchange type are introduced through the guiding catheter with the guide wire sliding within the stent-delivery catheter. The guide wire is first advanced out of the guiding catheter into the arterial vessel 16 and is advanced across the arterial lesion. Prior to implanting the stent, the cardiologist may wish to perform an angioplasty or other procedure (e.g., atherectomy) in order to open and remodel the vessel and the diseased area.
[0042] Referring to FIG. 2 , the stent delivery catheter assembly 11 is advanced over the guide wire so that the stent 10 is positioned in the target area. The stent-delivery catheter is subsequently advanced over the previously positioned guide wire until the stent is properly positioned across the lesion.
[0043] Referring now to FIGS. 2 and 3 , once in position, the dilation balloon 14 is inflated to a predetermined size to radially expand the stent 10 against the inside of the artery wall and thereby implant the stent within the lumen of the artery 16 . The balloon 14 is then deflated to a small profile so that the stent- delivery catheter may be withdrawn from the patient's vasculature and blood flow resumed through the artery.
[0044] The metallic cylindrical rings 12 of this embodiment are formed from tubular members and may be relatively flat in transverse cross-section. Thus, after implantation into the artery 16 as shown in FIG. 3 , minimal interference with blood flow occurs. Eventually the stent becomes covered with endothelial cell growth, which further minimizes blood flow interference. As should be appreciated by those skilled in the art that, while the above-described procedure is typical, it is not the only method used in placing stents.
[0045] The stent patterns shown in FIGS. 1-3 are for illustration purposes only and can vary in size and shape to accommodate different vessels or body lumens. Further, the stent 10 is of a type that can be used in accordance with the present invention.
[0046] Links 18 , 21 interconnect adjacent cylindrical rings 12 and may have cross-sections smaller, larger or similar to the cross-sections of the undulating components of the expandable cylindrical rings. The number and location of the links connecting the rings together can be varied in order to vary the desired longitudinal and flexural flexibility in the stent assembly structure in the unexpanded as well as expanded condition of the stent. These properties are important to minimize alteration of the natural physiology of the body lumen into which the stent assembly is implanted and to maintain the compliance of the body lumen which is internally supported by the stent assembly. Generally, the greater the longitudinal and flexural flexibility of the stent assembly, the easier and the more safely it can be delivered to the target site.
[0047] With reference to FIG. 4 , the stent 10 includes cylindrical rings 12 in the form of undulating portions. The undulating portions are made up of a plurality of U-shaped undulations 20 having radii that more evenly distribute expansion forces over the various members. After the cylindrical rings have been radially expanded, outwardly projecting edges 22 may be formed. That is, during radial expansion some of the U-shaped undulations may tip radially outwardly thereby forming outwardly projecting edges. These outwardly projecting edges can provide for a roughened outer wall surface of the stent and assist in implanting the stent in the vascular wall by embedding into the vascular wall. In other words, the outwardly projecting edges may embed into the vascular wall, for example arterial vessel 16 , as depicted in FIG. 3 . Depending upon the dimensions of the stent and the thickness of the various members making up the serpentine pattern, any of the U-shaped undulations may tip radially outwardly to form the projecting edges.
[0048] The cylindrical rings 12 can be nested such that adjacent rings slightly overlap in the longitudinal direction so that one ring is slightly nested within the next ring and so on. The degree of nesting can be dictated primarily by the length of each link, cylindrical ring, the number of undulations in the rings, the thickness of the rings, and the radius of curvature, of the rings all in conjunction with the crimped or delivery diameter of the stent. If the rings are substantially nested one within the other, it may be difficult to crimp the stent to an appropriate delivery diameter without the various struts overlapping. It is also contemplated that the rings may be slightly nested even after the stent is expanded, which enhances vessel wall coverage. In some circumstances, it may not be desirable to nest one ring within the other, which is also contemplated by the invention.
[0049] For the purpose of illustration only, the stent 10 is shown as a flat pattern in FIG. 5 so that the pattern of rings 12 and links 18 , 21 may be clearly viewed. Normally the stent of the present invention is formed of a cylindrical structure, however, it is beneficial to describe various parts to facilitate discussion. The rings in the present embodiment have an undulating shape including peaks 42 and valleys 44 formed as U-shaped undulations 20 which are out of phase with the U-shaped undulations of adjacent cylindrical rings. The particular pattern and how many undulations, or the amplitude of the undulations, are chosen to fill particular mechanical requirements for the stent, such as radial stiffness and longitudinal flexibility. Typically, each adjacent ring will be connected by at least one connecting link 18 , 21 . The number of cylindrical rings incorporated into the stent can also vary according to design requirements taking into consideration factors such as radial stiffness and longitudinal flexibility.
[0050] The substantially straight links 18 also can be formed with an undulating pattern to enable the stent to have higher flexibility and deliverability and may be formed in a number of different patterns according to design requirements. For example, the links can be formed with more or less surface area, larger or smaller cross-sections, curves or oscillations, and a variety of other shapes according to design requirements.
[0051] The stent patterns shown in FIGS. 1-5 are for illustration purposes only and can vary in shape and size to accommodate different vessels or body lumens. Thus, rings 12 connected by links 18 , 21 can have any structural shapes and are not limited to the aforedescribed undulating rings including U-shaped portions. Links connecting the rings can also include oscillating patterns, sinusoidal patterns and zig-zag patterns. One aspect of the invention also provides for various anchoring mechanisms for attaching the links to the rings.
[0052] For illustration purposes an embodiment of the stent of the present invention shown in FIGS. 1-5 can generally be divided into a proximal stent section 24 , a center stent section 26 and a distal stent section 28 . The proximal stent section includes one proximal ring 30 and a series of corresponding proximal links 32 , 33 . The proximal links are attached to a center ring 34 located in the center stent section. The center stent section includes other center rings and center links 36 , 37 interconnecting the center rings. The distal stent section includes a distal ring 38 and a series of distal links 40 , 41 connected thereto. Like the proximal links the distal links are attached to a center ring.
[0053] As shown in FIG. 5 , adjacent rings 12 are arranged out of phase along the longitudinal axis of the stent so that adjacent rings have peaks 42 aligned with valleys 44 . In this arrangement all adjacent rings appear to be mirror images of each other and out of phase. For example, the proximal ring 30 includes distal valleys and adjacent the proximal ring is a center ring 34 with proximal peaks. The peaks of the center ring are aligned with the valleys of the proximal ring so that these adjacent rings appear to be mirror images of each other. Accordingly, the valleys of this center ring are aligned with the peaks of the adjacent center ring and so on for the length of the stent.
[0054] In this embodiment embodiment the stent includes two types of links 18 , 21 . The substantially straight links are important for maintaining the structural integrity of the stent and three of these links are used between adjacent center rings 34 to reduce potential clamshell opening. Clamshell opening may occur upon expansion of the stent when less than three links are used for every pair of adjacent rings. The loop-shaped links with relatively smaller cross-sectional areas also help to minimize the clamshell opening effect while minimally reducing the flexibility of the stent. In the proximal stent section 24 and distal stent section 28 two substantially straight links are utilized to maintain flexibility while two loop-shaped links are used between every pair of adjacent rings throughout the stent.
[0055] In another embodiment shown in FIG. 6 , a stent 64 includes links 66 which are all substantially straight and similarly sized. The rings 62 each incorporate undulations with nine peaks 68 rather than ten peaks 42 as in the embodiment shown in FIGS. 1-5 . With a smaller number of undulations, there is more area between the peaks and valleys on each ring. The increased open area allows a delivery balloon to penetrate the stent farther when the stent is crimped onto a delivery catheter. This high degree of penetration helps to securely retain the stent. The links connect every third peak and valley of adjacent rings and are spaced evenly around the circumference of the stent to uniformly distribute load. The links also are circumferentially offset along the longitudinal axis of the stent so that flexibility is maximized.
[0056] In another embodiment shown in FIG. 7 , a stent 84 includes undulating rings 86 that are circumferentially offset from each other along the longitudinal axis of the stent to a lesser degree than the rings in FIG. 6 . The offset is such that two rings separate completely out of phase rings. In the proximal stent section 88 and the distal stent section 92 two links interconnect adjacent rings while in the center stent section 90 three links 94 interconnect adjacent rings. This configuration of links maximizes rigidity and minimizes the clamshell opening effect within the center stent section. The rings 86 each incorporate nine peaks 96 which help offset the rigidity provided by the three links for every pair of adjacent ring within the center section and the circumferential offset of the rings along the longitudinal axis. As in the embodiment shown in FIG. 6 , the links are circumferentially offset along the longitudinal axis to enhance flexibility. The space between the nine peaks within the rings of the present embodiment also enables the stent to have improved retention on the delivery catheter similar to the embodiment shown in FIG. 7 .
[0057] In another embodiment shown in FIG. 8 , a stent 98 includes modified U-shaped undulations 100 within the proximal ring 101 of the proximal stent section 102 while the center section 104 incorporates U-shaped undulations 105 as in FIGS. 1-7 . The modified undulations include a series of curves 108 therein to help retain the stent onto the delivery catheter. More particularly, the curves allow the delivery balloon to be securely held within the rings and therefore help to prevent movement of the stent with respect to the balloon. As shown in detail in FIG. 8A , the proximal ring includes a proximal ring section 116 , a center ring section 118 and a distal ring section 119 . The curved portion of the modified U-shaped undulation is located in the center ring section while the proximal ring section and the distal ring section are substantially similar to those of the U-shaped undulations in the center stent section and distal stent section. Two links 112 , 114 are used to couple adjacent rings in the proximal stent section and the distal stent section while three links 110 are used in the center stent section to connect every adjacent ring. Due to the relatively small number of links coupling the proximal ring and the distal ring to the center rings, flexibility for this configuration is high within the distal stent section and proximal stent section while the center stent section retains a higher degree of rigidity.
[0058] In another embodiment shown in FIG. 9 , therapeutic drugs can be uniformly loaded and distributed through reservoirs in the proximal ring 122 and in the distal ring 124 to help prevent restenosis within the proximal stent section 126 and distal stent section 128 of a stent 120 . More particularly, the proximal ring incorporates micro-channels 130 within its structure to help retain the therapeutic drug. Similarly, the distal ring incorporates micro-depots 132 which also help to retain the therapeutic drug. For illustration purposes both types of reservoirs are shown in the embodiment of FIG. 9 while in practice either or both may be incorporated into the stent. Additionally, either type of reservoir can be used on other rings within the stent and can be incorporated into the other embodiments as needed. For example, the micro-channels may be incorporated into the distal rings and the micro-depots may be incorporated into the proximal rings.
[0059] In the embodiment shown in FIG. 10 , a stent 134 includes reservoirs within the proximal links 136 and the distal links 138 similar to those in the proximal ring 122 and the distal ring 124 of the embodiment shown in FIG. 9 . More particularly this embodiment includes two links within the proximal stent section 140 incorporating micro-depots and two distal links within the distal section 142 incorporating micro-channels, both of which help to uniformly retain and distribute a therapeutic drug. For illustration purposes both types of reservoirs are shown in the embodiment of FIG. 10 while in practice either or both may be incorporated into the stent. Additionally, either type of reservoir can be used on other links within the stent and can be incorporated into the other embodiments as needed. For example, the micro-channels may be incorporated into the proximal links and the micro-depots may be incorporated into the distal links.
[0060] In keeping with the invention, the links of any embodiment may be formed from a flexible polymeric material, that is bendable and flexible to enhance longitudinal and flexural flexibility of the stent. The polymeric material forming the links can be taken from the group of polymers consisting of polyurethanes, polyolefins, polyesters, polyamides, flouropolymers and their co-polymers, polyetherurethanes, polyesterurethanes, silicone, thermoplastic elastomer (C-flex), polyether-amide thermoplastic elastomer (Pebax), fluoroelastomers, fluorosilicone elastomer, polydimethyl siloxones (PDMS), aromatic PDMS, silicon thermoplastic urethanes, poly (glycerol-sebacate) (PGS) (developed by Yadong Wang, MIT) and commonly referred to as biorubber, styrene-butadiene rubber, butadiene-styrene rubber, polyisoprene, neoprene (polychloroprene), ethylene-propylene elastomer, chlorosulfonated polyethylene elastomer, butyl rubber, polysulfide elastomer, polyacrylate elastomer, nitrile, rubber, a family of elastomers composed of styrene, ethylene, propylene, aliphatic polycarbonate polyurethane, polymers augmented with antioxidents, polymers augmented with image enhancing materials, polymers having a proton (H+) core, polymers augmented with protons (H+), butadiene and isoprene (Kraton), polyester thermoplastic elastomer (Hytrel), methacrylates, ethylene, acetate, alcohol, and polyvinyl alcohol.
[0061] The rings and the links (when metallic) may be made of suitable biocompatible material such as stainless steel, titanium, tungsten, tantalum, vanadium, cobalt chromium, gold, palladium, platinum, and iradium, and even high strength thermoplastic polymers. The stent diameters are very small, so the tubing from which they are made must necessarily also have a small diameter. For PTA applications, typically the stent has an outer diameter on the order of about 1.65 mm (0.065 inch) in the unexpanded condition, the same outer diameter of the tubing from which it is made, and can be expanded to an outer diameter of 5.08 mm (0.2 inch) or more. The wall thickness of the tubing is about 0.076 mm (0.003 inch). In the case of forming the stent from cobalt-chromium the wall thickness of the tubing may be reduced. For stents implanted in other body lumens, such as PTA applications, the dimensions of the tubing are correspondingly larger. While it is preferred that the stents be made from laser cut tubing, those skilled in the art will realize that the stent can be laser cut from a flat sheet and then rolled up in a cylindrical configuration with the longitudinal edges welded to form a cylindrical member.
[0062] The rings may also be made of materials such as super-elastic (sometimes called pseudo-elastic) nickel-titanium (NiTi) alloys. In this case the rings would be formed full size but deformed (e.g. compressed) to a smaller diameter onto the balloon of the delivery catheter to facilitate intraluminal delivery to a desired intraluminal site. The stress induced by the deformation transforms the rings from an austenite phase to a martensite phase, and upon release of the force when the stent reaches the desired intraluminal location, allows the stent to expand due to the transformation back to the more stable austenite phase. Further details of how NiTi super-elastic alloys operate can be found in U.S. Pat. Nos. 4,665,906 (Jervis) and 5,067,957 (Jervis). The NiTi alloy rings may be attached to the other rings through welding, bonding and other well known types of attachments.
[0063] The stent of the invention also can be coated with a drug or therapeutic agent. Further, it is well known that the stent (when both the rings and links are made from metal) may require a primer material coating such as a polymer to provide a substrate on which a drug or therapeutic agent is coated since some drugs and therapeutic agents do not readily adhere to a metallic surface. The drug or therapeutic agent can be combined with a coating or other medium used for controlled release rates of the drug or therapeutic agent. Representative examples of polymers that can be used to coat a stent in accordance with the present invention include ethylene vinyl alcohol copolymer (commonly known by the generic name EVOH or by the trade name EVAL), poly(hydroxyvalerate); poly(L-lactic acid); polycaprolactone; poly(lactide-co-glycolide); poly(hydroxybutyrate); poly(hydroxybutyrate-co-valerate); polydioxanone; polyorthoester; polyanhydride; poly(glycolic acid); poly(D,L-lactic acid); poly(glycolicacid-co-trimethylene carbonate); polyphosphoester; polyphosphoester urethane; poly(amino acids); cyanoacrylates; poly(trimethylene carbonate); poly(iminocarbonate); copoly(ether-esters) (e.g. PEO/PLA); polyalkylene oxalates; polyphosphazenes; biomolecules, such as fibrin, fibrinogen, cellulose, starch, collagen and hyaluronic acid; polyurethanes; silicones; polyesters; polyolefins; polyisobutylene and ethylene-alphaolefin copolymers; acrylic polymers and copolymers; vinyl halide polymers and copolymers, such as polyvinyl chloride; polyvinyl ethers, such as polyvinyl methyl ether; polyvinylidene halides, such as polyvinylidene fluoride and polyvinylidene chloride; polyacrylonitrile; polyvinyl ketones; polyvinyl aromatics, such as polystyrene; polyvinyl esters, such as polyvinyl acetate; copolymers of vinyl monomers with each other and olefins, such as ethylene-methyl methacrylate copolymers, acrylonitrile-styrene copolymers, ABS resins, and ethylene-vinyl acetate copolymers; polyamides, such as Nylon 66 and polycaprolactam; alkyd resins; polycarbonates; polyoxymethylenes; polyimides; polyethers; epoxy resins; polyurethanes; polybutylmethacrylate; rayon; rayon-triacetate; poly(glycerol-sebacate); cellulose acetate; cellulose butyrate; cellulose acetate butyrate; cellophane; cellulose nitrate; cellulose propionate; cellulose ethers; and carboxymethyl cellulose.
[0064] “Solvent” is a liquid substance or composition that is compatible with the polymer and is capable of dissolving the polymer at the concentration desired in the composition. Representative examples of solvents include chloroform, acetone, water (buffered saline), dimethylsulfoxide (DMSO), propylene glycol methyl ether (PM,) iso-propylalcohol (IPA), n-propylalcohol, methanol, ethanol, tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl acetamide (DMAC), benzene, toluene, xylene, hexane, cyclohexane, heptane, octane, pentane, nonane, decane, decalin, ethyl acetate, butyl acetate, isobutyl acetate, isopropyl acetate, butanol, diacetone alcohol, benzyl alcohol, 2-butanone, cyclohexanone, dioxane, methylene chloride, carbon tetrachloride, tetrachloroethylene, tetrachloro ethane, chlorobenzene, 1,1,1-trichloroethane, formamide, hexafluoroisopropanol, 1,1,1-trifluoroethanol, and hexamethyl phosphoramide and a combination thereof. The therapeutic substance contained in the coating can be for inhibiting the activity of vascular smooth muscle cells. More specifically, the therapeutic substance can be aimed at inhibiting abnormal or inappropriate migration and/or proliferation of smooth muscle cells for the inhibition of restenosis. The therapeutic substance can also include any active agent capable of exerting a therapeutic or prophylactic effect in the practice of the present invention. For example, the therapeutic substance can be for enhancing wound healing in a vascular site or improving the structural and elastic properties of the vascular site. Examples of therapeutic agents or drugs that are suitable for use with the polymeric materials include sirolimus, everolimus, actinomycin D (ActD), taxol, paclitaxel, or derivatives and analogs thereof. Examples of agents include other antiproliferative substances as well as antineoplastic, antiinflammatory, antiplatelet, anticoagulant, antifibrin, antithrombin, antimitotic, antibiotic, and antioxidant substances. Examples of antineoplastics include taxol (paclitaxel and docetaxel). Further examples of therapeutic drugs or agents that can be combined with the polymeric materials include antiplatelets, anticoagulants, antifibrins, antithrombins, and antiproliferatives. Examples of antiplatelets, anticoagulants, antifibrins, and antithrombins include, but are not limited to, sodium heparin, low molecular weight heparin, hirudin, argatroban, forskolin, vapiprost, prostacyclin and prostacyclin analogs, dextran, D-phe-pro-arg-chloromethylketone (synthetic antithrombin), dipyridamole, glycoprotein IIb/IIIa platelet membrane receptor antagonist, recombinant hirudin, thrombin inhibitor (available from Biogen located in Cambridge, Mass.), and 7E-3B® (an antiplatelet drug from Centocor located in Malvern, Pa.). Examples of antimitotic agents include methotrexate, azathioprine, vincristine, vinblastine, fluorouracil, adriamycin, and mutamycin. Examples of cytostatic or antiproliferative agents include angiopeptin (a somatostatin analog from Ibsen located in the United Kingdom), angiotensin converting enzyme inhibitors such as Captopril® (available from Squibb located in New York, N.Y.), Cilazapril® (available from Hoffman-LaRoche located in Basel, Switzerland), or Lisinopril® (available from Merck located in Whitehouse Station, N.J.); calcium channel blockers (such as Nifedipine), colchicine, fibroblast growth factor (FGF) antagonists, fish oil (omega 3-fatty acid), histamine antagonists, Lovastatin® (an inhibitor of HMG-CoA reductase, a cholesterol lowering drug from Merck), methotrexate, monoclonal antibodies (such as PDGF receptors), nitroprusside, phosphodiesterase inhibitors, prostaglandin inhibitor (available from GlaxoSmithKline located in United Kingdom), Seramin (a PDGF antagonist), serotonin blockers, steroids, thioprotease inhibitors, triazolopyrimidine (a PDGF antagonist), and nitric oxide. Other therapeutic drugs or agents which may be appropriate include alpha-interferon, genetically engineered epithelial cells, and dexamethasone.
[0065] While the foregoing therapeutic agents have been used to prevent or treat restenosis, they are provided by way of example and are not meant to be limiting, since other therapeutic drugs may be developed which are equally applicable for use with the present invention. The treatment of diseases using the above therapeutic agents are known in the art. Furthermore, the calculation of dosages, dosage rates and appropriate duration of treatment are previously known in the art.
[0066] The stent of the present invention can be made in many ways. One method of making the stent is to cut a tubular member, such as stainless steel tubing to remove portions of the tubing in the desired pattern for the stent, leaving relatively untouched the portions of the metallic tubing which are to form the stent. In accordance with the invention, it is preferred to cut the tubing in the desired pattern by means of a machine-controlled laser as is well known in the art.
[0067] After laser cutting the stent pattern the stents are preferably electrochemically polished in an acidic aqueous solution such as a solution of ELECTRO-GLO#300, sold by ELECTRO-GLO Co., Inc. in Chicago, Ill., which is a mixture of sulfuric acid, carboxylic acids, phosphates, corrosion inhibitors and a biodegradable surface active agent. Other electropolishing solutions are well known in the art. The stents may be further treated if desired, for example by applying a biocompatible coating.
[0068] Other methods of forming the stent of the present invention can be used, such as chemical etching; electric discharge machining; laser cutting a flat sheet and rolling it into a cylinder; and the like, all of which are well known in the art at this time.
[0069] The stent of the present invention also can be made from metal alloys other than stainless steel, such as shape memory alloys. Shape memory alloys are well known and include, but are not limited to, nickel-titanium and nickel/titanium/vanadium. Any of the shape memory alloys can be formed into a tube and laser cut in order to form the pattern of the stent of the present invention. As is well known, the shape memory alloys of the stent of the present invention can include the type known as thermoelastic martensitic transformation, or display stress-induced martensite. These types of alloys are well known in the art and need not be further described here.
[0070] Importantly, a stent formed of shape memory alloys, whether the thermoelastic or the stress-induced martensite-type, can be delivered using a balloon catheter of the type described herein, or in the case of stress induced martensite, be delivered via a catheter without a balloon or a sheath catheter.
[0071] While the invention has been illustrated and described herein, in terms of its use as an intravascular stent, it will be apparent to those skilled in the art that the stent can be used in other body lumens. Further, particular sizes and dimensions, number of peaks per ring, materials used, and the like have been described herein and are provided as examples only. Other modifications and improvements may be made without departing from the scope of the invention.
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The present invention is directed to a flexible expandable stent for implantation in a body lumen, such as a coronary artery. The stent generally includes a series of metallic cylindrical rings longitudinally aligned on a common axis of the stent and interconnected by a series of links which be polymeric or metallic. Varying configurations and patterns of the links and rings provides longitudinal and flexural flexibility to the stent while maintaining sufficient column strength to space the cylindrical rings along the longitudinal axis and providing a low crimp profile, enhanced stent security and radial stiffness.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation of U.S. patent application Ser. No. 12/267,488, filed Nov. 7, 2008, which is incorporated herein by reference.
BACKGROUND
[0002] 1. Field of the Inventions
[0003] Embodiments of the present invention relate to thin film gallium (Ga) electroplating methods and chemistries employing electrolytes or solutions comprising mixtures of water and certain classes of organic liquids. Such films have application in the field of electronic devices such as solar cells.
[0004] 2. Description of the Related Art
[0005] Thin film solar cells have attracted much attention lately because of their potential low cost. Thin film solar cells may employ, as their light absorbing layer or absorber, polycrystalline silicon, amorphous silicon, cadmium telluride (CdTe), copper indium gallium selenide (sulfide) (CIGS(S)), etc. The processing methods used for the preparation of thin film solar cell absorber layers can generally be classified as dry and wet processes. The dry processes include physical vapor deposition (PVD) and chemical vapor deposition (CVD) techniques, which are usually well developed, however, expensive. Wet processes include ink spraying or printing, chemical bath deposition (CBD) and electrochemical deposition (ED), also called electrodeposition or electroplating. Among these methods, CBD is popular for the preparation of some n-type semiconductor films like CdS, ZnSe, In—Se, etc. In ink deposition processes, inks comprising nano-particles dispersed in a solvent are deposited on a substrate. When the solvent evaporates away, it leaves behind a precursor layer comprising the nano-particles. The precursor layer is then sintered at high temperatures to form the absorber.
[0006] Electrochemical deposition techniques can provide thin precursor films which may then be converted into solar cell absorbers. One recent application of electroplated copper (Cu), indium (In) and gallium (Ga) films is in the formation of Cu(In,Ga)(Se,S) 2 or CIGS(S) type layers, which are the most advanced compound absorbers for polycrystalline thin film solar cells. It should be noted that the notation (In, Ga) means all compositions from 100% In and 0% Ga to 0% In and 100% Ga. Similarly, (Se,S) means all compositions from 100% Se and 0% S to 0% Se and 100% S. Applying electrodeposition to the formation of a CIGS(S) type absorber layer may involve a two-stage or two-step processing approach comprising a precursor deposition step and a reaction step. A thin In layer, for example, may be electroplated on a Cu layer. A thin Ga film may then be formed on the In layer to form a Cu/In/Ga stack precursor. The Cu/In/Ga precursor stack thus obtained may then be reacted with selenium (Se) to form a CIGS absorber. Further reaction with sulfur (S) would form a CIGS(S) layer. The CIGS(S) absorber may be used in the fabrication of thin film solar cells with a structure of “contact/CIGS(S)/buffer layer/TCO”, where the contact is a metallic layer such as a molybdenum (Mo) layer, the buffer layer is a thin transparent film such as a cadmium sulfide (CdS) film and transparent conductive oxide (TCO) is a transparent conductive layer such as a zinc oxide (ZnO) and/or an indium tin oxide (ITO) layer.
[0007] In a thin film solar cell employing a Group IBIIIAVIA compound absorber such as CIGS(S), the cell efficiency is a strong function of the molar ratio of IB/IIIA. If there are more than one Group IIIA materials in the composition, the relative amounts or molar ratios of these IIIA elements also affect the properties. For a Cu(In,Ga)(S,Se) 2 or CIGS(S) absorber layer, for example, the efficiency of the device is a function of the molar ratio of Cu/(In+Ga), where Cu is the Group IB element and Ga and In are the Group IIIA elements. Furthermore, some of the important parameters of the cell, such as its open circuit voltage, short circuit current and fill factor vary with the molar ratio of the IIIA elements, i.e. the Ga/(Ga+In) molar ratio. In general, for good device performance Cu/(In+Ga) molar ratio is kept at or below 1.0. For ratios close to or higher than 1.0, a low resistance copper selenide phase may form, which may introduce electrical shorts within the solar cells. As the Ga/(Ga+In) molar ratio increases, on the other hand, the optical bandgap of the absorber layer increases and therefore the open circuit voltage of the solar cell increases while the short circuit current typically may decrease. It is important for a thin film deposition process to have the capability of controlling both the molar ratio of IB/IIIA, and the molar ratios of the Group IIIA components in the composition. Therefore, if electrodeposition is used to introduce the Ga into the film composition, it is essential that the electroplated Ga films have smooth morphology and be free of defects such as pinholes. It should be noted that the typical thickness of Ga layers to be electroplated for CIGS(S) absorber formation is in the range of 50-300 nm and many prior art electroplated Ga layers display a peak-to-valley surface roughness in the range of 50-500 nm, which means that these films are very thick in some areas and very thin in others.
[0008] In an application of electroplated Ga layers to solar cell fabrication, the Ga layer may be electroplated to form precursor stacks with structures such as Cu/In/Ga, Cu/Ga/In, etc. These stacks may then be reacted at high temperature (typically in the range of 400-600° C.) with a Group VIA material such as Se and S to form a CIGS(S) absorber layer. The absorber layer may then be further processed to construct a solar cell. US Patent Application with publication No. 20070272558, entitled “Efficient Gallium Thin Film Electroplating Methods and Chemistries” filed by the applicants of this application and incorporated herein by reference, discloses new methods and chemistries to deposit Ga films with high plating efficiency. Other work on electrodeposition of Ga includes the publication by S. Sundararajan and T. Bhat (J. Less Common Metals, vol.11, p. 360, 1966) who utilized electrolytes with a pH value varying between 0 and 5. Other researchers investigated Ga deposition out of high pH solutions comprising water and/or glycerol. Bockris and Enyo, for example, used an alkaline electrolyte containing Ga-chloride and NaOH (J. Electrochemical Society, vol. 109, p. 48, 1962), whereas, P. Andreoli et al.(Journal of Electroanalytical Chemistry, vol. 385, page.265, 1995) studied an electrolyte comprising KOH and Ga-chloride. While some of these previous works used very corrosive solutions, i.e., pH=15, most of them were carried out under low plating efficiencies in low pH electrolytes, the plating efficiencies being typically 20% or lower. Glycerol, due to its high boiling temperature has also been used in high temperature (>100° C.) preparation of electrodeposition chemistries to plate molten globules of Ga—In alloys (see e.g. U.S. Pat. No. 2,931,758). Although, glycerol-based plating solutions may be adequate to obtain Ga deposits in the form of thick molten globules such deposits cannot be used in the formation solar cell absorbers such as thin film CIGS(S) compounds. From the foregoing, there is a need to develop Ga electrolytes and electrodeposition methods to generate smooth, uniform and defect-free Ga thin films with high plating efficiencies on surfaces of varying chemical composition. This way Ga layers may be electroplated onto different cathode surfaces for electronics applications, specifically for the fabrication of high quality CIGS(S) type thin film solar cell absorbers.
SUMMARY
[0009] An aspect of embodiments of the present invention is to provide an electrodeposition solution for depositing a gallium (Ga) thin film on a conductive surface. The electrodeposition solution includes a solvent including an organic solution, such as a mixture of at least one monohydroxyl alcohol and water and a Ga source. The electrodeposition solution further includes at least one of an acid and a salt for controlling the solution pH value and providing a high ionic conductivity in the plating solution. This solution can be used to plate Ga at a very low temperature.
[0010] Another aspect of embodiments of the present invention is to provide a method of electrodepositing a Ga thin film on a conductive surface. The method includes the steps of providing an electrodeposition solution that includes a mixture of at least one monohydroxyl alcohol and an aqueous solvent; a Ga source, and at least one of an acid and a salt to control the solution pH value and provide a good conductivity for plating; adjusting the pH of the electrodeposition solution between 0 and 7, preferably between 1 and 3; contacting the solution with an anode and the conductive surface; establishing a potential difference between the anode and the conductive surface; and electrodepositing the Ga thin film on the conductive surface. The freezing point of the electrodeposition solution can be significantly lower than that of water, and thus the electrodeposition solution of the present invention can be used at low temperatures to prevent Ga melting and alloying with the underlying materials and to obtain films with improved amounts of surface roughness.
BRIEF DESCRIPTION OF THE DRAWING
[0011] FIG. 1 is a schematic illustration of a gallium film electrodeposited on a conductive surface from an electrodeposition solution.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The embodiments of the present inventions provide methods and electrodeposition solutions or electrolytes to electrodeposit uniform, smooth and repeatable gallium (Ga) films. Through the use of various aspects of the present inventions it is possible to form micron or sub-micron thick Ga films on conductive surfaces from solutions mixed with aqueous and organic solvents such as alcohols. The present inventions may be used to form gallium films for manufacturing solar cell absorbers. Electrodeposition solutions of the embodiments of the present inventions may be used at very low temperatures to improve the surface morphology of electroplated Ga films.
[0013] FIG. 1 shows an exemplary gallium thin film 100 or layer electrodeposited on a surface 102 of a conductive layer 104 from an electrodeposition solution 106 using an electrodeposition method. The gallium thin film 100 may be a part of a precursor stack, which may include indium and copper layers. The conductive layer 104 may be a solar cell base comprising a substrate and a contact layer deposited on the substrate, or a precursor layer including at least one of a gallium layer, indium layer and copper layer formed on the base. During the electrodeposition process, the conductive layer 104 is brought into contact with the electrodeposition solution 106 and negatively polarized with respect to a positively polarized electrode (not shown) that is also in contact with the electrodeposition solution. A typical conductive layer 104 used by embodiments of the inventions comprise at least one of Cu, Ga, In, Mo, Ru, Ir and Os.
[0014] Gallium electrodeposition electrolytes and electrodeposition methods for solar cell manufacturing processes have many more stringent and special requirements than the electrodeposition methods and solutions employed for many other commonly plated metals such as Cu, Ni, Co, Pb, Sn, Ag, Au, Pt, and their alloys, etc. This stems from the facts that; i) Ga is one of the lowest melting point metals in existence, with a melting point of about 30° C., ii) Ga has a high negative electrodeposition potential and thus Ga electrodeposition efficiency is naturally low since high electrodeposition potentials cause hydrogen generation, in addition to Ga deposition, at the cathode surface in aqueous electrolytes, iii) hydrogen bubbles generated on a cathode surface form defects such as un-deposited regions unless such bubbles could immediately be removed from the surface, iv) Ga has a tendency to form low temperature melting alloys with many alloy-partner materials such as In, Cu, Ag, Pb, Sn, etc. Furthermore, such alloys may form during electrodeposition of Ga onto surfaces comprising any of such alloy-partner materials.
[0015] Electrodeposition solutions employing glycerol are very viscous and difficult to handle. The viscosity of glycerol at room temperature is 1500 centipoise (cP) compared to the viscosity of water, which is 1 cP. Gas bubbles such as hydrogen bubbles formed on the electroplated (cathode) surface during Ga plating in viscous electrolytes cannot be easily removed from that surface and therefore cause voids and other defects in the electrodeposited films. Such defects may be acceptable for some applications of thick electrodeposited Ga globules. However, they cannot be tolerated in electronic device applications such as solar cell absorber formation applications where they cause compositional non-uniformities, morphological non-uniformities, and pinholes etc., all of which negatively impact the device performance.
[0016] Glycerol based plating solutions become more viscous as their temperature is lowered and therefore the problems cited above may get worse at lower temperatures. One other important point about the electrodeposition process for Ga is its sensitivity to the nature of the substrate surface on which the electrodeposition is performed. For example, to form a Cu/In/Ga precursor stack, the Ga film needs to be electrodeposited on an In surface. To form a Cu/Ga/In precursor stack, on the other hand, Ga plating needs to be performed on a Cu surface. One Ga electrodeposition solution that performs well for plating Ga on a Cu surface may not perform well for electrodepositing Ga on an In surface because the electrodeposition efficiency of Ga on one surface may be very different from its electrodeposition efficiency on another surface.
[0017] As mentioned above, gallium is a low melting point material with a melting temperature of around 30° C. As a result, when electrodeposited out of aqueous electrodeposition solutions kept at about room temperature (20-25° C.), it often forms rough films comprising molten surface features, especially at high electrodeposition current densities such as current densities greater than about 5 mA/cm 2 . This is because even though the electrodeposition solution may be at a temperature lower than the melting point of Ga, the local temperature on the cathode surface may actually exceed this melting point due to the heat generated by the electrodeposition current. As further mentioned above, when Ga is electrodeposited on surfaces of materials that easily form alloys with Ga, molten droplets of Ga alloys with low melting temperatures may be formed on such surfaces. If the Ga film is electrodeposited over In and/or Cu, the local heating and Ga melting may actually promote alloying between the plated Ga film and the underlying In and/or Cu because there are low melting alloy phases between Ga and these materials such as In—Ga alloy phases and CuGa 2 alloy phase. As a result, the surface roughness of the deposit may further be increased due to the above mentioned reaction and the formation of molten alloy phases. For example, Mehlin et al. (Z. Naturforsch, vol. 49b, p.1597 (1994)) attributed the rough morphology of their electroplated Ga layers to the alloying of the electrodeposited Ga with the underlying Cu surface of the cathode and the formation of a molten CuGa 2 alloy.
[0018] Gallium may be electrodeposited from the electrodeposition solution at temperatures below −10° C., preferably below −20° C., most preferably below −30° C., so that local melting of the deposited Ga and its possible reaction with the materials on the cathode surface are avoided. Furthermore, at these low temperatures, the electrodeposition current densities may be increased to levels above 5 mA/cm 2 , preferably above 10 mA/cm 2 and even above 20 mA/cm 2 without causing melting and/or alloying on the cathode surface. As a result, the electrodeposition rate and therefore the process throughput may be increased while, at the same time, the deposited film roughness is reduced. All of these benefits are important for the successful use of electrodeposited Ga layers in thin film solar cell manufacturing. For example, the melting point of methanol is −97° C. and the freezing point of a methanol/water mixture is a function of the ratio of methanol to water in the electrodeposition solution. A mixture of 75% methanol and 25% water, for instance, has a freezing point of −82° C. (−115° F.). This means that a Ga plating electrodeposition solution comprising 75% methanol and 25% water may be operated at a temperature as low as about −70-80° C., thus avoiding the melting, reaction and surface roughness problems described above.
[0019] The electrodeposition solution may be used to electroplate Ga thin films onto conductive surfaces with a considerably high electrodeposition efficiency of greater than 40%. The electrolyte solution may comprise water and an organic solvent with a room temperature viscosity of less than about 10 cP, preferably less than about 5 cP. Examples of such organic solvents include monohydroxyl alcohols such as methanol, ethanol, and isopropyl alcohol. These organic solvents also have very low freezing points.
[0020] As well known in the field of chemistry, an alcohol is defined to be a hydrocarbon derivative in which a hydroxyl group (—OH) is attached to a carbon atom of an alkyl or substituted alkyl group. If the alcohols have two (—OH) groups, such as ethylene glycol and propylene glycol, they are classified as diols or glycols. Glycerol or sugar alcohol has three (—OH) groups and a boiling point of 290° C. Glycols also have boiling points close to 200° C. Therefore, diols containing two (—OH) groups or other organic compounds containing 3 or more (—OH) groups may be useful for high temperature electrodeposition solutions. However, as explained before, such organic compounds have shortcomings including high viscosity giving rise to defectivity in the electrodeposited thin layers. Furthermore, the freezing point of glycerol is too high for the purpose of good quality thin film Ga electrodeposition. The viscosities of ethylene glycol, propylene glycol and diethylene glycol, which are all diols, are 16 cP, 40 cP and 32 cP, respectively. Their freezing points, on the other hand are about −13° C., −59° C. and −10° C., respectively. The viscosity and the freezing point of glycerol, which has three (—OH) groups, are 1500 cP and +18° C., respectively.
[0021] The electrodeposition solutions of one embodiment of the present inventions employ at least one monohydroxyl alcohol mixed with water as solvent. Monohydroxyl alcohols contain only one (—OH) or hydroxyl group and they include methanol, primary alcohols (such as ethanol, 1-propanol, isobutanol, 1-pentanol, 1-hexanol, 1-heptanol), secondary alcohols (such as isopropyl alcohol, 2-butanol, 2-methyl-2-butanol, 2-hexanol) and tertiary alcohols (such as tert-butanol, tert-amyl alcohol). The viscosities of monohydroxyl alcohols are typically below 10 cP, mostly below 5 cP, and their freezing points vary from −12° C. for 2-methyl-2-butanol, to −126° C. for 1-propanol. For example, viscosities of methanol, ethanol, 1-propanol, isobutanol, and isopropyl alcohol are 0.59 cP, 1.2 cP, 1.94 cP, 3.95 cP and 1.96 cP, respectively. Their respective freezing points are about −97° C., −114° C., −126° C., −108° C., and −89° C. As can be seen, these low viscosities and extremely low freezing temperatures are very desirable properties for thin Ga film electrodeposition.
[0022] The electrodeposition solution may further comprise an acid and/or a salt to control the pH and increase the solution conductivity. The electrodeposition solution may further include a Ga source dissolved in the electrolyte, such as Ga chloride, Ga sulfate, Ga sulfamate, Ga perchloride, Ga phosphate, Ga nitrate, etc. Additional inorganic and organic acids and their alkali metal (lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr)) and/or alkali earth metal (beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) and radium (Ra)) salts can be added to the electrodeposition solution to provide a buffer to stabilize the solution pH and to increase the conductivity of the electrodeposition solution. Concentrations of additional organic or inorganic acids and/or their alkali metal salts may not be high since the Ga salts in the composition also provide some of the ionic conduction. Acids such as sulfamic acid, citric acid, acetic acid, tartaric acid, maleic acid, boric acid, malonic acid, succinic acid, phosphoric acid, oxalic acid, formic acid, arsenic acid, benzoic acid, sulfuric acid, nitric acid, hydrochloric acid, and amino acids, may be used. As stated above, Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr and Ba salts of these acids could be added along with the acid to adjust the pH, provide buffering and increase the electrodeposition solution conductivity. The electrodeposition solution pH range may be acidic or basic, but is preferably between 0 and 7.
[0023] The standard potential of Ga electrodeposition from aqueous electrolytes is E 0 Ga(III)/Ga =−0.52 V. At this potential, the hydrogen evolution is aggressive, especially in an acidic aqueous solution. This is why the Ga electrodeposition processes typically display low electrodeposition efficiencies in aqueous acidic electrodeposition solutions. The mixture of an organic solvent described in embodiments of the inventions reduces the amount of water in the electrodeposition solution and thereby reduces the tendency of hydrogen evolution from water and increases the Ga electrodeposition efficiency. Because of the low viscosity of the present electrodeposition solutions any hydrogen bubbles formed on the cathode surface are easily swept away reducing or eliminating defectivity in the electrodeposited Ga films. The embodiments of the present inventions will now be further described in the following example.
EXAMPLE
[0024] To demonstrate the wide range of capabilities of the developed electrodeposition solution chemistries and techniques, the electrodeposition conditions of the Ga layers were widely varied using a factorial design with three factors and three levels. The exemplary solvent was a mixture of methanol and de-ionized water. The Ga source used was GaCl 3 . Sulfamic acid was used in the electrodeposition solution to increase the ionic conductivity. The three factors that were changed in the experiments were: i) the volume ratios of methanol to water (M/W ratio), ii) the concentration of GaCl 3 , and, iii) the concentration of the sulfamic acid. The pH was kept in the range of 1.3 and 2. All of the electrodeposition tests were carried out using a current density of 30 mA/cm 2 for 150 seconds without stifling the electrodeposition solutions. According to the Faraday's Law, the total charge passed to the cathodes was 4.5 Coulombs/cm 2 . Therefore, a Ga film thickness of about 1.83 μm was expected if the Ga electrodeposition efficiency were 100%. The anode was a platinum (Pt) mesh. The cathode surface comprised a thin Cu layer. All of the solvent combinations resulted in clear miscible solutions of methanol and water. The thickness of the resultant Ga films was measured to evaluate the electrodeposition efficiencies.
[0025] M/W ratio in the present example (or more generally the organic solvent-to-water ratio of the electrodeposition solutions) was found to be an important variable. This ratio may be in the range of about 0.05-99, preferably in the range of about 0.1-10, more preferably in the range of about 0.2-5. The Ga concentration range in the electrolyte is preferably more than 0.1M. The maximum concentration of Ga is determined by the amount of Ga source dissolvable in the solvent with a specific M/W ratio, a typical concentration being in the range of 0.2-0.6M. The sulfamic acid concentration of the present example could be changed from zero to about 0.5M. However, the preferred range of the acid concentration in general is 0.05-0.2M. At higher concentrations of acid, for example over 0.5 M, the Ga electrodeposition efficiency was found to reduce to less than 10%. It should be noted that, within the preferred ranges of the above variables, Ga layers may be electrodeposited at electrodeposition efficiencies greater than 40% using the electrodeposition solutions or electrolytes.
[0026] The results of the above experiments may be summarized as follows: i) As the M/W ratio got higher, the electrodeposition efficiency also got higher; ii) as the sulfamic acid concentration became greater than 0.2M, the plating efficiency started to decline, and iii) in general higher Ga concentration in the electrodeposition solution yielded higher electrodeposition efficiencies.
[0027] The Ga source in the electrodeposition solution of the embodiments of the present inventions may comprise stock solutions prepared by dissolving Ga metal into their ionic forms as well as by dissolving soluble Ga salts, such as sulfates, chlorides, acetates, sulfamates, carbonates, nitrates, phosphates, oxides, perchlorates, and hydroxides in the solvent of the electrodeposition solution. As mentioned above, the polar organic solvents (monohydroxyl alcohols) are used in the formulation since they need to be miscible with water and dissolve certain amount of Ga salts, acids and their salts. Many primary, secondary or tertiary monohydroxyl alcohols may also be used in place of or in addition to the methanol used in the above example. These alcohols include but are not limited to ethanol, 1-propanol, isobutanol, 1-pentanol, 1-hexanol, 1-heptanol, isopropyl alcohol, 2-butanol, 2-methyl-2-butanol, 2-hexanol, tert-butanol and tert-amyl alcohol. The acids used in the embodiments of the present inventions may cover a wide range including sulfamic acid, acetic acid, citric acid, tartaric acid, maleic acid, boric acid, succinic acid, phosphoric acid, oxalic acid, formic acid, arsenic acid, benzoic acid, sulfuric acid, nitric acid, hydrochloric acid, and amino acids, etc. The concentrations of the acids and their alkali metal and alkali metal earth salts can be adjusted according to the pH requirements of the solutions. The solution pH values can be widely varied between acidic and basic ranges. The preferred range is a pH of 0 to 7. A more preferred range is between 1 and 3. For the pH values larger than 3, some acids with low pK a , i.e., maleic acid, oxalic acid, and phosphoric acid, may be preferred to both control the solution pH and at the same time complex the Ga 3+ cations and avoid precipitation of Ga(OH) 3 .
[0028] It should be noted that although the monohydrated alcohols constitute the preferred ingredients in the Ga electrodeposition solutions of embodiments of the present inventions, in certain embodiments some other organic solvents with appropriate viscosity and freezing point values may also be employed. These organic solvents include, but are not limited to acetonitrile (viscosity of about 0.35 cP and freezing point of about −45° C.), acetone (viscosity of about 0.32 cP and freezing point of about −95° C.), formaldehyde (viscosity of about 0.5 cP and freezing point of about −117° C.), and dimethylformimide (viscosity of about 0.9 cP and freezing point of about −61° C.), butyronitrile (viscosity of about 0.55 cP and freezing point of about −112° C.), docholoromethane (viscosity of about 0.41 cP and freezing point of about −97° C.), N-methyl-pyrrolidinone (freezing point of about −23° C.), γ-Butyrolactone (freezing point of about −43° C.), 1-2-Dimethoxy-ethane (viscosity of about 0.5 cP and freezing point of about −69° C.), and tetrahydrofuran (viscosity of about 0.5 cP and freezing point of about −108° C.). It should also be noted that other organic ingredients may also be added to the electrodeposition solution as long as they do not appreciably alter its desired properties described previously. These additional organic ingredients include, but are not limited to diols and alcohols with three (—OH) groups.
[0029] Both direct current (DC) and pulsed or variable voltage/current may be utilized during the electrochemical deposition processes in embodiments of the present inventions. The temperature of the electrodeposition solution may be in the range of −120° C. to +30° C. depending upon the nature of the organic solvent, the organic solvent-to-water volume ratio, and the nature of the cathode surface. If the cathode surface comprises materials that alloy easily at low temperature with Ga, then low temperatures such as temperatures in the range of −120° C. to −20° C., may be beneficially selected for the electrodeposition solution.
[0030] The electrodeposition solutions of the embodiments of the present inventions may comprise additional ingredients. These include, but are not limited to, grain refiners, surfactants, wetting agents, dopants, other metallic or non-metallic elements etc. For example, organic additives such as surfactants, suppressors, levelers, accelerators and the like may be included in the formulation to refine its grain structure and surface roughness. Organic additives include but are not limited to polyalkylene glycol type polymers, propane sulfonic acids, coumarin, saccharin, furfural, acrylonitrile, magenta dye, glue, SPS, starch, dextrose, and the like.
[0031] Although the present inventions are described with respect to certain preferred embodiments herein, modifications thereto will be apparent to those skilled in the art.
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An electrochemical deposition method and electrolyte to plate uniform, defect free and smooth gallium films are provided. In a preferred embodiment, the electrolyte may include a solvent that comprises water and at least one monohydroxyl alcohol, a gallium salt, and an acid to control the solution pH and conductivity. The method electrodeposits a gallium film possessing sub-micron thickness on a conductive surface. Such gallium layers are used in fabrication of semiconductor and electronic devices such as thin film solar cells.
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BACKGROUND OF THE INVENTION
This invention relates to a drum-type weft detaining device of a shuttleless loom, enabling a so-called dual-pick pass weft insertion wherein, after twice sequential weft pickings by a weft inserting device, no weft picking takes place for a time period at which sequential twice weft pickings take place by another weft inserting device.
In connection with shuttleless looms, it has been proposed to employ a drum type weft detaining device wherein a weft yarn of a predetermined length is detained or stored on a drum prior to weft picking through a weft inserting device. The drum is stationary or rotatable in timed relation to the operational cycle of the loom
However, such drum type weft detaining devices have not enabled a so-called dual-pick pass weft insertion. In the dual-pick pass weft insertion, two weft yarns are alternately inserted, with sequential twice pickings, into a warp shed respectively from two weft inserting devices, in which it is necessary to detain one weft yarn in the length required for twice weft pickings during the twice sequential weft pickings of another weft yarn. Furthermore, it is necessary to catch the detained weft yarn at its central section to prevent the weft yarn length for the subsequent picking from being drawn-off during the former picking. The thus complicated manner for weft detaining has not been able to be achieved by the conventional drum type weft detaining device.
BRIEF SUMMARY OF THE INVENTION
According to the present invention, in a shuttleless loom of the type enabling a so-called dual-pick pass weft insertion, the weft detaining device comprises a drum on which a weft yarn is wound prior to its introduction to a weft inserting means, which drum is formed with a frustoconical section tapered toward the weft inserting means side, and a cylindrical section connected to said frustoconical section. A first catching member is provided to catch the weft yarn on the drum in the vicinity of the border between the frustoconical and cylindrical sections for at least a period of weft pickings, in timed relation to the operational cycle of the loom. A second catching member is provided to catch the weft yarn on the drum for at least a period of the first time weft picking in sequential twice weft pickings and to release its catching action to the weft yarn for at least a period of the second time weft picking in sequential twice weft pickings, in timed relation to the loom operational cycle. Additionally, a third catching member is provided to catch the weft yarn on the drum cylindrical section for at least a period during which the detaining of the weft yarn required for the succeeding twice weft pickings is completed. The thus arranged weft detaining device enables so-called dual-pick pass weft insertion, ensuring twice sequential weft pickings with accurately measured weft lengths, though the weft detaining device is of the drum type.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the shuttleless loom weft detaining device according to the present invention will be clearly appreciated from the following description taken in conjunction with the accompanying drawings in which like reference numerals and characters designate the corresponding parts and elements thoughout all the embodiments, in which:
FIG. 1 is a top plan view of an essential part of a shuttleless loom which is equipped with a pair of weft detaining devices each being an embodiment in accordance with the present invention;
FIG. 2 is a front elevation of one of the weft detaining devices of FIG. 1;
FIG. 3 is a view showing the vertical section of the weft detaining device of FIG. 2;
FIG. 4 is a side elevation of an essential part of the weft detaining device of FIG. 2;
FIG. 5 is a timing chart of the operation of the shuttleless loom of FIG. 1;
FIGS. 6 to 10 are side views of a drum of the weft detaining device of FIG. 2 at various operational timings, illustrating the operation of the weft detaining device;
FIG. 11 is a front elevation of an essential part of the shuttleless loom equipped with another embodiment of the weft detaining device in accordance with the present invention;
FIG. 12 is a vertical sectional view of the weft detaining device of FIG. 12;
FIG. 13 is a side elevation of the weft detaining device of FIG. 12; and
FIGS. 14 to 18 are side views of a drum of the weft detaining device of FIG. 11 at various operational timings, illustrating the operation of the weft detaining device.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1 to 10 of the drawings, there is shown a water-jet shuttleless loom equipped with two weft detaining devices each of which is an embodiment according to present invention, in which the weft detaining device is of the stationary drum type. The shuttleless loom consists of two weft inserting water injection nozzles 2, 2' which are supported respectively by two nozzle holders 3, 3' which are in turn fixed on a frame 1 of the shuttleless loom. Two weft guides 4, 4' are supported respectively by two stays 5, 5' which are secured respectively to the nozzle holders 3, 3' which are respectively located rearward of the nozzles 2, 2'. Accordingly, two weft yarns 7, 7' from the weft detaining devices 6, 6' discussed hereinafter are introduced respectively into the nozzles 2, 2' through the weft guides 4, 4' and then picked or inserted into a warp shed (not shown) by means of water-jets ejected from the nozzles 2, 2'. The reference numerals 8, 8' designate bobbins as weft supply means or sources, respectively.
The two weft detaining devices 6, 6' are the same in construction and function, and therefore the explanation will be made hereinafter only on the weft detaining device 6. A bracket 12 having a bearing section 12a is secured to the frame 1 of the shuttleless loom through a horizontally disposed bracket 11 which is directly secured to the frame of the loom by bolts, as shown in FIG. 2. The bracket 12 is connected at its bottom part to the bracket 11 with bolts and nuts so that the axis of the bearing section 12a is in alignment with that of the weft guide 4.
As clearly shown in FIG. 3, a shaft 14 is rotatably supported at its central section within the bearing section 12a through a ball bearing 13. A toothed pulley 15 is fixedly mounted on a rear section of the rotatable shaft 14. A toothed belt 16 is provided to connect the pulley 15 and a drive pulley (not shown) to rotate the rotatable shaft 14 in accordance with the operation of the loom. In this case, the transmission ratio or the ratio between the rotation of the rotatable shaft 14 and the operational cycle of the loom is 2:1 in which the rotatable shaft 14 rotates two times per each operational cycle of the loom.
A support member 18 is rotatably mounted through ball bearings 17 on a front section of the rotatable shaft 14 so as to be rotatable relative to the shaft 14. A drum 20 forming part of the weft detaining device 6 is fixedly supported by the support member 18 by means of bolts 19. The drum 20 is formed with an outer peripheral surface which comprises a frustoconical section 20a connecting to the rear end R of the drum and whose diameter gradually decreases in the direction of the weft inserting nozzle 2, i.e. from the rear end R toward the front end F of the drum 20. The drum outer peripheral surface further comprises a cylindrical section 20b which integrally connects with the frustoconical section 20a and extends to the front end F of the drum 20. The diameter of the cylindrical section 20b is so set that the length of the weft yarn 7 wound about four times around the cylindrical section 20b corresponds to the weft yarn length requires for each pick. The cylindrical section 20b may be slightly tapered toward the front end F of the drum 20. Magnets 21 are securely attached on a part of the inside surface of the drum 20, which magnets are positioned opposite to magnets 24 which are located outside of and spaced from the drum 20. The magnets 24 are secured to a support 23 which is firmly connected to the bracket 11 through stud bolts 22 which are mounted to the bracket 11. As a result, the drum 20 is maintained at the stationary state regardless of the rotation of the rotatable shaft 14, under the action of the magnetic attraction generated between the magnets 21 and 24.
The rotatable shaft 14 is formed along its axis with an elongate weft introduction hole 25 which opens to the rear end face of the rotatable shaft 14. Additionally, a drawing-off opening 26 is formed at the outer surface of the shaft 14 so as to communicate with the weft introduction hole 25. Securely attached on the rotatable shaft peripheral surface forward of the opening 26 is a weft winding guide member 27 which is formed at its top section with a guide opening 28 through which the weft yarn 7 is guided onto the frustoconical section 20a of the drum 20. The weft winding guide member 27 is bent to approach the surface of the frustoconical section 20a. Accordingly, the weft yarn 7 drawn from the weft supply source 8 is introduced into the weft introduction hole 25 and then into the drawing-off opening 26. Subsequently, after being introduced along the winding guide member 27 and passed through the opening 28, the weft yarn 7 is wound around the frustoconical section 20a and the cylindrical section 20b, in which the weft yarn 7 is caught by at least one of first, second and third hook levers 31, 32 and 33 which will be discussed hereinafter. Thereafter, the weft yarn 7 will be passed through the weft guide 4.
As shown, the hook levers 31, 32 and 33 are pivotally and rotatably mounted on a fixed shaft 34 and formed at their end sections with first, second and third hook sections 31a, 32a and 33a, respectively. The hook sections 31a, 32a and 33a are located to be able to be inserted respectively into through-holes 35, 36 and 37. The holes 35, 36 are located in the vicinity of the border between the frustoconical section 20a and the cylindrical section 20b. The holes 35, 36 are slightly spaced from each other in the direction of the periphery of the drum 20. The hole 37 is located on the cylindrical section 20b. In this instance, the holes 35, 36, 37 pass through or pierce the wall of the drum 20. The first, second and third hook levers 31, 32, 33 are further provided at the other ends thereof with cam rollers or followers 42, 43 and 44, respectively. The hook levers 31, 32, 33 are biased counterclockwise in FIG. 4 by means of springs 39, 40 and 41, respectively, each spring being disposed between a stationary pin 38 and a pin (no numeral) mounted on each hook lever, so that the cam rollers 42, 43, 44 are always in contact with rotatable cams 45, 46 and 47, respectively. The cam 45, 46, 47 are securely mounted on a rotatable shaft 48 which rotates 1/4 times per each operational cycle of the loom. The rotatable shaft 48 is rotatably supported by a bearing section 49a forming part of a base 49 by which the fixed shaft 34 and the stationary pin 38 are firmly supported, as shown in FIG. 1. The cams 45, 46, 47 are formed respectively with high lobe sections 45A, 46A and 47A, and low lobe section 45B, 46B and 47B. With this arrangement, when the high lobe section 45A, 46A, or 47A of the cam 45, 46, or 47 contacts the cam roller 42, 43, or 44, the hook lever 31, 32, or 33 rotates clockwise in FIG. 4. As a result, the hook section 31a, 32a, or 33a enters or is inserted into the hole 35, 36, or 37 of the drum 20. On the contrary, when the low lobe section 45B, 46B, or 47B of the cam 45, 46, or 47 contacts the cam roller 42, 43, or 44, the hook section 31a, 32a, or 33a is withdrawn from the drum hole 35, 36, or 37. It is preferable that each hook section 31a and 32a of the first and second hook levers 31, 32 is formed at its tip portion with a tapered or inclined surface which is generally parallel to the tapered surface of the drum frustoconical section 20a, in order that the weft yarn 7 can well be separated when the hook section enters or is inserted into the hole of the drum.
The manner of operation of the weft detaining device will be discussed hereinafter with reference to FIGS. 5 to 10. In FIG. 5, "1 to 6 (CYCLES)" designates 1st to 6th operational cycles of the loom. "0°, 90°, 180°, 270°, and 360°" designate the operational timings or angles within each loom operational cycle, in which "0° (=360°)" is the timing of beating up by a reed (not shown). "INJECTION" in terms of "WEFT PICKING" designates a water-jet ejection from the nozzle 2 as a weft inserting means. The numerals "1 to 4" in terms of "DETAINING" designate the number of winding times of the weft yarn wound around the drum. "ENTER" and "WITHDRAW" in terms of "FIRST, SECOND and THIRD HOOK SECTIONS (33a, 33b, 33c)" designate the state where the hook section of the hook lever enters or is inserted into the hole of the drum, and the state where the hook section is withdrawn from the hole of the drum, respectively.
During the operation of the loom, the rotatable shaft 14 rotates two times per each loom operational cycle; however the drum 20 cannot rotate and is maintained at the stationary state by virtue of the magnetic attraction generated between the magnet 21 attached to the drum 20 and the stationary magnet 24. Accordingly, with the rotation of the rotatable shaft 14, the weft winding guide member 27 rotates around the periphery of the drum 20, so that the weft yarn 7 is wound around the frustoconical section 20a of the drum 20. Then, the weft yarn 7 of the frustoconical section 20a slides along the slope of the frustoconical section 20a by its own tension and moves to the cylindrical section 20b, pushing ahead the wound weft yarn located forward thereof.
When the loom operational cycle reaches a timing immediately before the first time weft picking in the 1st loom operational cycle (1st CYCLE in FIG. 5), the hook sections 31a, 32a, 33a of the first, second, third hook levers 31, 32, 33 enter or are inserted into the holes 35, 36, 37 of the drum 20, respectively. In this state, the weft yarn 7 is caught by the first hook section 31a and is then caught by the second hook section 32a after being wound four times around the drum 20 in the vicinity of the border between the frustoconical and cylindrical sections 20a, 20b; the weft yarn 7 is further caught by the third hook section 33a after being wound four times around the drum cylindrical section 20b.
At the first time weft picking, the third hook section 33a is withdrawn from the hole 37 of the drum 20, so that the weft yarn 7 wound between the second and third hook sections 32a, 33a is drawn off to be picked into the warp shed under the influence of water-jet ejection through the nozzle 2 which ejection begins immediately before this withdrawal of the third hook section. When the amount of the weft yarn wound between the second and third hook sections 32a, 33a becomes zero or nothing by the weft picking, the weft yarn 7 is caught by the second hook section 32a to complete the weft picking. Until the completion of this weft picking, the weft yarn 7 is wound about two times on the drum at the frustoconical section (20a) side relative to the first hook section 31a by the rotation of the weft winding guide member 27 (See FIG. 6 which is at 270° in 1st loom operational cycle).
At the second time weft picking in the 2nd loom operational cycle, the second hook section 32a is withdrawn from the hole 36 of the drum 20, so that the weft yarn 7 wound between the first and second hook sections 31a, 32a is drawn off to be picked or inserted into the warp shed, under the influence of water-jet ejection through the nozzle 2 which ejection begins immediately before the withdrawal of the second hook section 32a. When the amount of the weft yarn 7 wound between the first and second hook sections 31a, 32a becomes zero or nothing by this weft picking, the weft yarn 7 is caught by the first hook section 31a to complete the weft picking. Until this time, the weft yarn 7 is wound about four times on the drum 20 at the frustoconical section (20a) side relative to the first hook section 31a by the rotation of the weft winding guide member 27 (See FIG. 7 which is at 230° in the 2nd loom operational cycle).
Thereafter first the third hook section 33a is again inserted into the hole 37 of the drum 20 (See FIG. 8 which is at 270° in the 2nd loom operational cycle). Subsequently, the first hook section 31a is withdrawn from the hole 35 of the drum 20, so that the weft yarn 7 which has been wound about four times around the frustoconical section 20a slides down along the slope of the frustoconical section 20a and moves onto the cylindrical section 20b, and is caught by the third hook section 33a. Almost simultaneously with the withdrawal of the first hook section 31a, the second hook section 32a is inserted into the hole 36 of the drum 20 to detain the weft yarn 7 wound four times between the second hook section 32a and the third hook section 33a (See FIG. 9 which is at 315° in the 2nd loom operational cycle). Accordingly, the weft yarn 7 to be supplied hereinafter by the weft winding guide member 27 is wound around the drum 20 at the frustoconical section (20a) side relative to the second hook section 32a.
In the 3rd and 4th loom operational cycles, the weft yarn 7' detained by another weft detaining device 6' is inserted into the warp shed through the weft inserting nozzle 2', in which sequential twice weft pickings take place as shown in FIG. 5. In the weft detaining device 6, the weft yarn 7 is wound about four times on the drum 20 at the frustoconical section (20a) side relative to the second hook section 32a until the weft picking in the 4th loom operational cycle is completed.
Then, the first hook section 31a is inserted into the hole 35 of the drum 20 to detain the weft yarn 7 wound four times between it and the second hook section 32a (See FIG. 10 which is at 275° in the 4th loom operational cycle). Accordingly, the weft yarn 7 to be supplied thereinafter by the weft winding guide member 27 is wound on the drum 20 at the frustoconical section (20a) side relative to the first hook section 31a.
In the 5th and 6th loom operational cycles, sequential twice weft pickings take place in the same manner as in the 1st and 2nd loom operational cycles, respectively.
FIGS. 11 to 18 illustrate another embodiment of the weft detaining device 6" in accordance with the present invention, in which the weft detaining device is of the rotating drum type. In this embodiment, the same reference numerals and characters as in the embodiment of FIGS. 1 to 10 designate the corresponding parts and elements. While only one weft detaining device 6" is shown and described, another similar weft detaining device is located parallel with the device 6", though not shown, similar to in the embodiment of FIGS. 1 to 10.
In the weft retaining device 6", a hollow shaft 51 is rotatably supported at its central section in the bearing section 12a by the ball bearing 13. The toothed pulley 15 is fixedly mounted on a rear section of the hollow shaft 51 by means of a key (no numeral). The toothed belt 16 connects the pulley 15 and a drive pulley (not shown) to rotate the hollow shaft 51 in timed relation to the operational cycle of the loom. The hollow shaft 51 rotates two times per each operational cycle of the loom.
A support ring 52 having a slit (not shown) is mounted on a front portion of the hollow shaft 51, and is fixed in position by a fastening member 53. A drum 54 is fixed on an annular flange section 52a of the support ring 52 in such a manner that a flange section 55 of the drum 54 is positioned between the front surface of the flange section 52a and a base plate 56, and is fixed thereto as a single member by bolts 57. The drum 54 is provided at its peripheral surface with a first frustoconical section 54a, tapered in the direction from the rear end section R to the front end section F of the drum 54. The frustoconical section 54a terminates at a first small diameter section S 1 . A second frustoconical section 54b continues from the first diameter section S 1 , tapering in the reverse direction to that of the first frustoconical section 54a, and terminates at a large diameter section L. A third frustoconical section 54c continues from the large diameter section L, tapering in the same direction as the first frustoconical section 54a, and terminates at a second small diameter section S 2 , smaller than the first diameter section S 1 . A cylindrical section 54d continues from the second small diameter section S 2 and extends to the front end section F of the drum 54. The cylindrical section 54d has a diameter smaller than that of S 1 . In this instance, the diameter of the cylindrical section 54d is set so that the length of the weft yarn wound four times on the cylindrical section 54d corresponds to the weft length required for each weft picking.
A cam operating shaft 59 is disposed within the hollow shaft 51 on bearings 58 so as to be rotatable relative to the hollow shaft 51. The cam operating shaft 59 is securely provided at its rear end section with a toothed pulley 60 which is rotated by a toothed belt 61 driven by a drive pulley (not shown) of the loom, so that the cam operating shaft 59 rotates 1/4 times per each loom operational cycle. The front end section of the cam operating shaft 59 is located inside of the drum 54 and is securely provided with a gear 62 which is mounted on the shaft (59) front end section. The gear 62 engages a gear 64 which is rotatably mounted on a shaft 63 mounted on the base plate 56. The gear 64 is provided with a flange section 64a which is located spaced from and parallely with the gear 64. Three plate like cams 65, 66 and 67 are secured to the side surface of the flange section 64a so as to be parallel with the flange section 64a. The three cams 65, 66, 67 are parallel to and spaced from each other as shown in FIG. 12. The gear ratio between the gears 62 and 64 is 1:1, so that each of cams 65, 66, 67 rotates 1/4 times, revolving around the gear 62, per each loom operational cycle.
First, second and third hook levers 71, 72 and 73 of the same shape are rotatably mounted at their end sections on a fixed shaft 68 which is mounted on the base plate 56. Cam rollers 74, 75 and 76 are rotatably attached to the central sections of the first, second and third hook levers 71, 72, 73, respectively. Springs 78, 79 and 80 are disposed between hook levers 71, 72, 73 and a pin 77 which is planted on the base plate 56, so that the first, second and third hook levers 71, 72, 73 are biased to urge the cam rollers 74, 75, 76 to contact the cams 65, 66, 67, respectively. The first, second and third hook levers 71, 72, 73 are formed with first, second and third hook sections 71a, 72a and 73a which are located to face holes 81, 82, 83, respectively. Through-holes 81, 82 are formed in the vicinity of the border between the third frustoconical section 54c and the cylindrical section 54d. Through-hole 83 is formed on the cylindrical section 54d. The hook sections 71a, 72a, 73a of the first, second and third hook levers 71, 72, 73 are constructed and arranged to project out of the drum 54 through the holes 81, 82, 83 when high lobe sections 65A, 66A, 67A of the cams 65, 66, 67 contact cam rollers 74, 75, 76, respectively, and to be withdrawn into the drum 54 when low lobe sections 65B, 66B, 67B of the cams 65, 66, 67 contact the cam rollers, respectively. It is preferable that each hook section 71a, 72a of the first and second hook levers 71, 72 is formed at its tip portion with a tapered or inclined surface which is generally parallel with the tapered surface of the drum third frustoconical section 54c, in order that the weft yarn 7 can well be separated when the hook section projects out of the drum through the hole of the drum.
A rod like guide 84 is fixed on the tip end of a stay 85 which is fixed to the bracket 12. The guide 84 is formed with at least two grooves 84a and 84b, and is positioned so that the axis thereof is parallel to that of the drum 54. The weft yarn 7 drawn from a yarn supply means or source such as a cone-shaped bobbin engages the groove 84a and then passes on to a groove formed at the drum first small diameter section S 1 between the first and second frustoconical sections 54a, 54b. Subsequently, the weft yarn 7 engages the guide groove 84b and passes on to the third frustoconical section 54c and on to the cylindrical section 54d, and thereafter is caught by at least one of the hook sections 71a, 72a, 73a and passed through the guide 4.
The manner of operation of the weft detaining device 6" will be illustrated hereinafter. During the operation of the loom, the rotatable shaft 51 rotates two times per each loom operational cycle. Accordingly, the weft yarn 7 introduced through the groove 84a of the guide 84 is supplied on the drum first frustoconical section 54a, and is then wound on the groove between the adjacent frustoconical sections 54a, 54b. Thereafter, when contacted with the drum third frustoconical section 54c through the groove 84b of the guide 84, the weft yarn 7 slides along the slope of the frustoconical third section 54c by its own tension and moves to the cylindrical section 54d, pushing ahead the weft yarn wound forward thereof.
When the loom operational cycle reaches a timing immediately before the first time weft picking in the 1st loom operational cycle, the first, second and third hook sections 71a, 72a, 73a of the first, second and third hook levers 71, 72, 73 enter or are inserted into the holes 81, 82, 83 of the drum 54, respectively, so as to project outside of the outer surface of the drum 54. In this state, the weft yarn 7 is caught by the first hook section 71a and is then caught by the second hook section 72a after being wound four times around the drum 54 in the vicinity of the border between the third frustoconical and cylindrical sections 54c, 54d; the weft yarn 7 is further caught by the third hook section 73a after being wound four times around the drum cylindrical section 54d.
At the first time weft picking, the third hook section 73a is withdrawn from the hole 83 of the drum 54, so that the weft yarn 7 wound between the second and third hook sections 72a, 73a is drawn off to be picked or inserted into the warp shed under the influence of water-jet ejection through the nozzle 2, which ejection begins immediately before this withdrawal of the third hook section. When the amount of the weft yarn 7 wound between the second and third hook sections 72a, 73a becomes zero or nothing by the weft picking, the weft yarn 7 is caught by the second hook section 73a to complete the weft picking. Until the completion of this weft picking, the weft yarn 7 is wound about two times on the drum at the third frustoconical section (54c) side relative to the first hook section 71a (See FIG. 14).
At the second time weft picking in the 2nd loom operational cycle, the second hook section 72a is withdrawn from the hole 82 of the drum 54, so that the weft yarn 7 wound between the first and second hook sections 71a, 72a is drawn off to be picked or inserted into the warp shed, under the influence of water-jet ejection through the nozzle 2 which ejection begins immediately before the withdrawal of the second hook section 72a. When the amount of the weft yarn 7 wound between the first and second hook sections 71a, 72a becomes zero or nothing by this weft picking, the weft yarn 7 is caught by the first hook section 71a to complete the weft picking. Until this time, the weft yarn 7 is wound about four times on the drum 54 at the third frustoconical section (54c) side relative to the first hook section 71a (See FIG. 15).
Thereafter, first the third hook section 73a is again inserted into the hole 83 of the drum 54 to be projected outside of the drum outer surface (See FIG. 16). Subsequently, the first hook section 31a is withdrawn from the hole 83 of the drum 54, so that the weft yarn 7 which has been wound about four times around the third frustoconical section 54c slides down along the slope of the third frustoconical section 54c and moves onto the cylindrical section 54d, and is caught by the third hook section 73a. Almost simultaneously with the withdrawal of the first hook section 71a, the second hook section 72a is inserted into the hole 82 of the drum 54 to be projected outside of the drum outer surface so as to detain the weft yarn 7 wound four times between the second hook section 72a and the third hook section 73a (See FIG. 17). Accordingly, the weft yarn 7 to be supplied hereinafter is wound around the drum 54 at the third frustoconical section (54c) side relative to the second hook section 72a.
In the 3rd and 4th loom operational cycles, a weft yarn (not shown) detained by another weft detaining device (not shown) is inserted into the warp shed through another weft inserting nozzle (not shown), in which sequential twice weft pickings take place. In the weft detaining device 6", the weft yarn 7 is wound about four times on the drum 54 at the third frustoconical section (54c) side relative to the second hook section 72a until the weft picking in the 4th loom operational cycle is completed.
Then, the first hook section 71a is projected into the hole 81 of the drum 54 to be projected outside of the drum outer surface so as to detain the weft yarn 7 wound four times between the first hook section 71a and the second hook section 72a (See FIG. 18). Accordingly, the weft yarn 7 to be supplied thereafter is wound on the drum 54 at the third frustoconical section (54c) side relative to the first hook section 71a.
In the 5th and 6th loom operational cycles, sequential twice weft pickings take place in the same manner as in the 1st and 2nd loom operational cycles, respectively.
It will be understood that the third hook section 33a, 73a in the above-discussed embodiments may be replaced with an annular brush which is disposed around and in contact with the outer peripheral surface of the drum cylindrical section 20b, 54d in such a manner as to be positioned along the cylindrical section (20b) periphery passing through location of the hole 37, 83 for the third hook section 33a, 73a, in order to provide resistance to the weft yarn 7 to be drawn off. Otherwise, an annular resistance-providing member is directly disposed on and along the location of the above-mentioned annular brush, in place of the third hook sections 33a, 73a.
While only water-jet looms have been shown and described, it will be understood that the principle of the present invention is applicable to air-jet loom.
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A weft detaining device of a shuttleless loom, including a drum having a frustoconical section and a cylindrical section, a first catching member for catching the weft yarn on the drum in the vicinity of the border between the frustoconical and cylindrical sections for at least a period of weft pickings, a second catching member for catching the weft yarn on the drum for at least a period of the first time weft picking in sequential twice weft pickings and releasing its catching action to the weft yarn for at least a period of the second time weft picking of the sequential twice weft pickings, and a third catching member for catching the weft yarn on the drum cylindrical section for at least a period wherein the detaining of the weft yarn for the succeeding twice sequential weft pickings is completed, thereby enabling a so-called dual-pick pass weft insertion though the weft detaining device is of the drum type.
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This application is a Continuation of prior U.S. application Ser. No. 08/344,582, filed Nov. 18, 1994, now abandoned.
BACKGROUND OF THE INVENTION
1. Field Of The Invention
The invention relates to a process for treating hardwood pulp with enzymes to reduce vessel element picking.
2. Background Art
Hardwood pulp is used in the paper industry to produce a variety of end products. Some of these products are designed specifically for the printing and book publishing industries. The paper used in these industries has a high content of hardwood pulp which gives good formation, opacity and printability. However, one problem with regard to the use of hardwood pulps results from their basic structure. Hardwoods contain two principle cell types. These are fiber cells and vessel element cells. The non-fibrous vessel cells transport water throughout the entire tree. They do not add strength or quality to the paper and, therefore, are not desirable. The structures remain intact through the pulping, bleaching and refining processes. During the papermaking process, these vessels can remain on the paper surface and not bonded to the fibers. The problem in printing is that the large unbonded vessel elements on the surface of the sheet get picked out by the printing press during the printing operation. This results in ink not being applied to all parts of the paper where it was intended to be applied. The vessels could also remain on the roll causing voids or spots to form. The net result is that the paper is of unacceptable quality.
In the past, vessel picking problems have been addressed using sizing, coating or refining technologies. The first two approaches have been unsuccessful in fully combating this problem and the latter approach tends to require significant amounts of capital and energy. Refining tends to be the most successful in reducing vessel picking (although high reductions have not been achieved). Many mills are reluctant to spend the capital required to reduce this problem. Therefore, combating this problem has become an issue that is not only costly in the industry, both to tolerate and to prevent, but usually goes unaddressed or accepted as normal.
Enzymes have been used in many different applications, and one in particular in the pulp and paper industry. Xylanase enzymes have been used to improve the bleachability of kraft pulps. These enzymes attack the reprecipitated xylan and allow better accessibility to delignify and bleach the pulp. Early work in this technology used xylanase enzyme preparations that had significant cellulase activity. These cellulases supposedly actively broke down the usable pulp fiber and reduced the fiber strength. Therefore, enzyme suppliers were heavily encouraged to remove any cellulase activity and purify the xylanases.
U.S. Pat. No. 5,202,249 (Kluepfel) involves a process using an endo-xylanase enzyme, having a high specific activity, for the treatment and/or biobleaching of lignocellulosic pulps. It is asserted that improved brightening and delignification is achieved. Kluepfel states:
"Preferably, the endo-xylanase is substantially cellulase-free. By the term `substantially cellulase-free` is meant those systems which do not contain sufficient amounts of cellulase to effect the unfavourable hydrolysis of glucosidic linkages present in the cellulose when the enzyme is applied to cellulose pulps."
"It is also preferable that the endo-xylanase is obtained from a host microorganisms wherein the host microorganisms mutant strain is characterized by it having a cellulase-negative activity. Cellulase-negative, when used in this context, is defined as a strain which produces a cellulase-free xylanase which is essentially free from extracellular cellulase." Col. 2, line 65, to col. 4, line 9!
U.S. Pat. No. 5,116,746 (Bernier et al.) discloses a process using a cellulase-free endo-xylanase for the treatment of lignocellulosic material for delignification, brightening and viscosity improvement. A cellulase-negative microorganism overexpresses the xylanase gene to provide the endo-xylanase.
U.S. Pat. No. 5,179,021 (du Manoir et al.) discloses bleaching lignocellulosic material by oxygen bleaching followed by an enzymatic treatment with a substantially cellulase-free xylanase. Du Manoir et al. stated that, in the manufacture of pulp for the purpose of paper-making, the effect of a cellulase enzyme would be detrimental owing to the resulting decrease in the degree of polymerization of the cellulose that would occur. In du Manoir et al., when an enzyme mixture containing xylanase also contains substantial amounts of cellulase, the cellulase is removed by any method known for the purification of xylanase, or the cellulase is selectively rendered inactive by any acceptable chemical or mechanical treatment.
Holm, Hans C., "The Use Of Enzymes In The Pulp And Paper Industry," World Pulp & Paper Technology 1994, (1993), pages 181 to 183, discloses the use of xylanase as being beneficial for subsequent bleaching purposes. Pulpzyme HB is said to work best at around neutral pH. (Pulpzyme HB is a xylanase preparation which is virtually free of cellulase activity, i.e., a trace or less, about 10 EGU/g.) The Holm article, in discussing possible future applications, said that it has been reported that cellulases reduce the amount of energy required to beat mechanical pulp and that treating pulp with a cellulase improves the dewatering of the paper web on a paper machine. (Nowhere in the Holm article is a combination cellulase and xylanase described.)
"Development Of Bleaching Technology In Finland", Paperi ja Puu, 74, No. 2, (1992), pages 102 to 106, discloses treating hardwood pulp with xylanase at pH 4 to 7 and 50° to 70° for 1 to 3 hours whereby there was a reduction of bleaching chemicals in the subsequent bleaching step.
Pedersen, Lars Saaby, et al., "Bleach Boosting Of Kraft Pulp Using Alkaline Hemicellulases," A-06152, (April 1991), 15 pages, discloses that alkaline xylanase preparations completely free of cellulase activity boost the bleachability of softwood kraft pulp. The two alkaline xylanases showed good bleach boosting effects at pH 8 and 9, respectively. Brownstock pulp is treated before the conventional bleaching sequence. The article mentions literature dealing with the use of hemicellulases for bleach boosting application. Such enzymes worked at acid pH (4 to 5) and apparently required long treatment times (12 to 24 hours).
There are two abstracts of a Japanese article that describe the use of a cellulase enzyme to reduce the vessel picking of pulp. The abstracts mention that the treatment was especially effective on eucalyptus which is a hardwood. The pure cellulase enzyme used in the Japanese article is marketed under the name Vesselex. Vesselex is stated to be used for the suppression of vessel pick formation. The abstracted article is Ishizaki, H., Jpn. Tappi J., 46, No. 1, (January 1992), pages 149 to 155.
There is an abstract of Uchimoto, I., et al., Jpn. J. Pap. Technol., No. 2, (February 1990), pages 1 to 5, that describes the use of Vesselex (a Trichoderma cellulase) to treat pulp to improve vessel picking.
BROAD DESCRIPTION OF THE INVENTION
The objective of the invention is to provide a method for treating hardwood pulp with an enzyme mixture prior to bleaching and refining which will reduce vessel element picking on the paper machine without significant pulp degradation. Other objectives and advantages of the invention are set out herein or are obvious herefrom to one skilled in the art.
The objectives and advantages of the invention are achieved by the process of the invention.
The invention process uses a mixture of cellulases and xylanases to chemically change the hardwood vessel elements, rendering them susceptible to breaking under normal mill refining, thus not requiring any additional refining equipment. The process involves treating hardwood brownstock (unbleached) pulp with a cellulase/xylanase mixture. The pulp treatment is done prior to bleaching and refining. The prior art generally did not use cellulase-containing enzymes for fear of pulp degradation. The invention has the goal of substantial vessel pick reduction without significant pulp degradation. The invention excludes the use of a pure cellulase enzyme (for example, Vesselex) and the use of a xylanase which is substantially free of cellulase activity. Xylanases are hemicellulases. The concomitant use of cellulases and xylanases in the proper proportions is a core factor of the invention.
As used herein, the term "cellulase/xylanase mixture" means that the enzyme mixture contains a substantial amount of cellulases, namely, at least a sufficient amount of cellulases to achieve substantial hydrolysis of the glucosidic linkages in the cellulose when the enzyme mixture is applied to aqueous cellulose pulps. Cellulase-free xylanases and xylanase-free cellulases are not within the scope of the invention process. In the cellulase/xylanase mixture, both the cellulases and xylanases are active.
Preferably the cellulase/xylanase mixture is obtained by natural expression from a microorganism, as opposed to a cellulase/xylanase mixture prepared by mixing the individual enzymes.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a graph of enzyme vessel pick reduction in a mill trial.
DETAILED DESCRIPTION OF THE INVENTION
The aqueous hardwood pulp slurry can, for example, be that of northern or southern hardwood. While is it preferred to employ a kraft pulp, other chemically digested pulps and mechanically-prepared pulps can be used. An unbleached pulp is used. The hardwood pulp can be prepared typically in a digester in the presence of chemicals such as sodium hydroxide and sodium sulfide (to produce a kraft pulp) or sulfites, usually sodium or magnesium, (to produce a sulphite pulp). (Kraft pulp is often prepared by digestion with a mixture of caustic soda, sodium carbonate and sodium sulfide.) The removal of lignin content of wood pulps is measured by a permanganate oxidation test according to a Standard Method of the Technical Association Of The Pulp And Paper Industry (TAPPI), and is reported as a Kappa Number. The chemical pulp from the digester still contains an appreciable amount of residual lignin at this stage, and in some cases is suitable for making construction or packaging paper without further purification. For the manufacture of printing and book publishing papers, however, the pulp is too dark in color and must be delignified and brightened by bleaching. It is at this point that the process of the present invention can be employed, i.e., before the bleaching of the lignocellulosic material, said material referred to herein as chemical hardwood brownstock pulp.
There are four different kinds of wood pulp: mechanical or chemimechanical pulp, sulfite pulp, sulfate or Kraft pulp, and soda pulp. The first is prepared by purely mechanical (or semi-mechanical) means, the other three by chemical means. The mechanical pulp contains all of the wood except the bark. Chemical pulps, however, are essentially pure cellulose, the undesirable lignin and the other noncellulosic components of the wood having been dissolved away by the treatment. Because of this, chemical pulps are much superior to mechanical (or groundwood pulp) for fine papermaking.
It has been found that treating hardwood brownstock pulp with an enzyme mixture containing primarily xylanase, but with substantial cellulase activity, chemically affects the vessel elements so that they are more susceptible to breaking through normal mill refining.
Unbleached hardwood brownstock is treated with an enzyme mixture in a manner that simulates the brownstock high density storage tower. The brownstock is at a consistency between 5 and 12 percent. The pulp is pH adjusted (if necessary) to a range of 4 to 10, with either acid or alkali, that corresponds with the optimum pH range for that specific enzyme mixture. The pulp is at a temperature between 100° to 154° F. (52° to 68° C.) for a reaction time of 30 to 180 minutes. The temperature also corresponds to the optimum temperature of the specific enzymes used. When the enzyme mixture is added to the pH adjusted pulp, mixing takes place as performed by a thick stock pump. The mixture can be agitated at various speeds with the use of various mixing devices which simulate a thick stock pump. The cellulase/xylanase mixture can be applied as it is produced in a fermentation broth, or a concentrated form thereof, or as a composition prepared from either a more concentrated composition of the cellulase/xylanase mixture or a dried preparation of the cellulase/xylanase mixture. Thereafter, preferably no mixing takes place, simulating high density pulp storage and normal mill conditions. High density storage towers normally have poor or no mixing. The unbleached hardwood pulp can be enzyme treated in one or more stages. After enzyme treatment, the pulps are fully bleached to a GE or TAPPI brightness of 80 percent or greater for use in the printing and book publishing industry.
The invention enzyme treatment effectively reduces hardwood vessel picking in fully bleached hardwood pulp handsheets by up to 70 percent or more. The enzymes can be chosen so as to vary the amount of vessel picking reduction, if desired. While the enzyme mixtures effectively reduce vessel picking, the pulp strength properties of Instron tensile (breaking length), tear (Elmendorf) and burst (Mullen) have not been negatively affected.
The hardwood pulp usually is a pulp of a species of oak, maple, poplar, birch, chestnut, aspen, beech, walnut, eucalyptus or mixtures thereof.
The hardwood pulp is produced from the Kraft process, Sulfite process, or any other commercially feasible process. Preferably the hardwood pulp is a chemically-digested hardwood pulp, most preferably (unbleached) hardwood Kraft pulp.
The consistency of the hardwood brownstock (bleached) pulp to be treated is usually from about 0.1 to about 30 weight percent, preferably about 2 to about 12 weight percent, based upon the oven-dry (O.D.) weight of the pulp.
The acid to adjust the pH of the hardwood pulp before the enzyme treatment can be any suitable inorganic or organic acid which does not have an adverse effect on the enzyme treatment of the hardwood pulp. Examples of suitable inorganic acids are sulfuric acid, sulfurous acid, nitric acid, nitrous acid, phosphoric acid, phosphorous acid and mixtures thereof. The preferred inorganic acid is sulfuric acid. Chlorine-containing acids should be avoided when Pulpzyme HA is used. Examples of suitable organic acids are benzoic acid, bromoacetic acid, maleic acid, formic acid, lactic acid, malic acid, acetic acid, butyric acid, propionic acid, citric acid, oxalic acid, succinic acid, picolinic acid and mixtures thereof. The preferred organic acid is acetic acid.
The base used to adjust the pH of the hardwood pulp before the enzyme treatment can be any suitable inorganic or organic base which does not have an adverse effect on the enzyme treatment of the hardwood pulp. Examples of suitable inorganic bases are sodium hydroxide, zinc hydroxide, ammonium hydroxide, aluminum hydroxide, potassium hydroxide and mixtures thereof. The preferred inorganic base is sodium hydroxide. Examples of suitable organic bases are aniline, tripropylamine, ethylamine, propylamine, acetamide, acetanilide, diethylamine, methylamine and mixtures thereof. The preferred organic base is ethylamine.
As used herein, acids are usually defined as being substances whose molecules ionize in water solution to give the hydrogen ion(s) from their constituent elements. As used herein, bases are usually defined as being substances which ionize in water to give the hydroxyl ion(s) from their constituent elements.
Preferably an enzyme mixture is used which has an optimum pH range of 6 to 8, particularly preferred of 7 to 8.
The enzyme mixture used is a mixture of cellulase and xylanase enzymes--there must be a substantial cellulase activity. The term cellulase includes all varieties of cellulases, endo and exo. The term xylanase includes all varieties of xylanases, endo and exo. The enzyme mixture can contain other enzymes than cellulases and xylanases. However, the cellulase is not the primary component. Xylanase is the primary component of the mixtures. The enzyme mixtures can be of bacterial or fungal origin. The cellulase/xylanase mixture should have a cellulase activity of at least 200 EGU/g, preferably at least about 300 EGU/g, and a xylanase activity of at least 200 XYU/g, preferably at least 300 XYU/g and best at about 500 XYU/g.
The most preferred cellulase/xylanase enzyme mixture is Pulpzyme HA, which is produced by the microorganism Trichoderma longbrachiatum. It is a product of Novo Nordisk Bioindustrials Inc., Enzyme Process Division, of Connecticut. The preferred operative pH for the enzyme mixture is 7. Pulpzyme HA is a brown liquid preparation. The Pulpzyme HA enzyme mixture contains xylanases, that is, endo-xylanase (endo-1,4-beta-D, specifically EC 3.2.1.8) and exo-xylanase (exo-1,4-beta-D, specifically EC 3.2.1.37), cellulases, that is, endo-glucanase (possibly 2 or 3 types), cellobiohydrolase (possibly 2 or 3 types) and beta-glucosidase (possibly 2 or 3 types), acetyal esterase and alpha galactosidase. The cellulase/xylanase enzyme mixture has low activity towards crystalline cellulose. One xylanase unit (XYU) is defined as the amount of enzyme which under standard conditions (pH 3.8, 30° C., 20 min. incubation) degrades larchwood xylan to reducing carbohydrates with a reducing power corresponding to 1 μmol xylose. One endo-glucanase unit (EGU) is defined as the amount of enzyme which under standard conditions (pH 6.0, 40° C., 30 min. incubation) lowers the viscosity of a carboxymethyl cellulose solution to the same extent as an enzyme standard defining 1 EGU. The Pulpzyme HA is standardized to a xylanase activity of 500 XYU/g and contains a cellulase activity of about 300 EGU/g. (A trace cellulase activity would be less than 50 EGU/g.)
At a temperature of 40° C. and a reaction time (in a pulp) of 20 minutes, the xylanase in Pulpzyme HA exhibits a relative activity of 60 percent or more at a pH of 3.5 to 6 (a pH range of 4 to 5 gives a greater xylanase activity/effect). A product brochure for Pulpzyme HA of Novo Nordisk Bioindustrials Inc., Enzyme Process Division, states: "By proper selection of process conditions (e.g., pH 6.5, 45° C.) undesirable effects of the cellulase activity may be further reduced." FIG. 2 in the product brochure shows almost zero percent relative cellulase activity and about 40 percent relative xylanase activity at pH 7. While theoretically there should be little or no cellulase activity at about pH 7, the invention secured the best results at about pH 7 when using Pulpzyme HA. The preferred pH for Pulpzyme HA is about 7 to 8, although a range of 6 to 8 gives good results.
A preferred cellulase/xylanase enzyme mixture is SP 342. The multi-enzyme complex known by the designation/name SP 342 includes cellulase, glucanase, hemi-cellulase and pentosanase activities. SP 342 is a product of Novo Nordisk Bioindustrials Inc., Enzyme Process Division. SP 342 is usually in the form of a stabilized liquid preparation. A brochure says that SP 342 is active in slightly acidic to mild alkaline conditions and at moderate temperatures. FIG. 1 in the brochure shows about 100 percent relative activity in the pH range of 5 to 7.
The process uses conditions which correspond with the activity ranges of the enzymes used. The enzyme dosage is effective even at 0.1 weight percent of fiber or less.
The hardwood pulp is treated with the enzyme prior to bleaching and refining. The enzyme can be inhibited after the treatment by heating the pulp to a sufficient temperature. At the end of the time period for the cellulase/xylanase treatment, the resultant treated material can be used directly or thickened, and the treated material then used for further processing.
The enzyme treated pulp is bleached to a GE or TAPPI brightness of 80 or greater and refined prior to the paper machine. The pulp is subsequently treated in various ways depending upon the type of paper desired.
The conventional method for further delignifying and bleaching pulp has been to employ a variety of multi-stage bleaching sequences, including anywhere from three to six stages, or steps, and with or without washing between steps. The objective in bleaching is to provide a pulp, in the case of chemical pulps, of sufficiently high brightness and strength for the manufacture of paper and tissue products. Characteristically, pulps of GE or TAPPI brightness of 80 to 86 percent are produced. The bleaching sequences can be based on the use of chlorine and chlorine-containing compounds, in one form or another. Some of the chlorine-containing compounds that are used are chlorine, chlorine dioxide, and hypochlorites, usually sodium hypochlorite. Chlorine, with or without admixture of chlorine dioxide, is commonly employed to initiate the bleaching of chemical pulp, followed by extraction of the chlorine-treated pulp in an aqueous alkaline medium. Also oxygen can be used as the delignifying and bleaching agent. One application is the use of oxygen in conjunction with a conventional alkaline extraction stage.
The resultant paper product is any paper that ink is applied to and vessel picking will reduce the quality of the paper, such as, printing and book publishing papers.
Vesselex is a liquid cellulase preparation standardized at 100 U/g FPase which is marketed by Solvay Biosciences Pty. Ltd., Victoria, Australia. When hardwood pulp (Eucalyptus) is used as the raw material for the manufacture of paper, the vessels which remain in the paper cannot properly accept the ink during printing and the ink at the site of the vessels comes off causing the vessel pick phenomena. Solvay Biosciences asserts that Vesselex is a cellulase enzyme which has been specially developed to reduce the formation of vessel picks in paper manufactured from hardwood pulp. The process of using Vesselex in the paper industry uses pulp thickening and then enzyme (from an enzyme holding tank at 5° C.) added to white water which is fed to a static mixer and the mixture is then added to a pulp chest which is sent to a refinery. The stated conditions were: pulp concentration, 5 to 6 percent; pH, 5.0 to 5.5; enzyme dose, 0.02 to 0.03 percent (w/w); temperature, 30° to 40° C.; and reaction time, not less than 4 hours. Regarding the prevention of vessel pick formulation by Vesselex cellulase: at an enzyme dosage of zero percent (w/w), the vessel picks were 185 (count per 10 sqr. cms.); at an enzyme dosage of 0.1 percent, the vessel picks were 18; and at an enzyme dosage of 0.2 percent, the vessel picks were 22. It is reported that, as the Vesselex cellulase dosage increases, the pulp degradation increases, but at the ideal dosage of 0.03 to 0.05 percent there is almost no pulp loss. It is also reported that the Vesselex cellulase is completely inactivated in one minute under normal machine drying conditions at 120° C.
Vesselex is used for the prevention of vessel pick formation. However, the invention is different, for example, because of different conditions: pH (5.0 to 5.5, Vesselex vs. pH 6 to 8, invention), temperature (30° to 40° C., Vesselex vs. 52° to 68° C., invention), reaction time (4 hours, Vesselex vs. 0.5 to 3 hours, invention), and pulp concentration (5 to 6 percent, Vesselex vs. 5 to 15 percent, invention). Most importantly, cellulase use can prove detrimental for paper properties other than vessel picking, and thus its use should be minimized. The disclosed discovery allows for the beneficial end product of vessel picking by using decreased levels of cellulase activity, and thus reducing the detrimental effects of cellulase use.
Bernier et al. (U.S. Pat. No. 5,116,746) used a cellulose-free endo-xylanase enzyme (obtained from a cellulase-negative recombinant microorganism) for pulp delignification. The endo-xylanase may contain a trace of cellulase which in activity terms is zero to 50 EGU/g (the higher the activity, the larger the amount of cellulase). The endo-xylanase is basically and relatively a single component enzyme composition. Bernier et al. uses host microorganisms of the species Streptomyces lividans for transformation to the cellulase-negative recombinant microorganism which has cellulase-negative activity. In the Bernier et al. process, there is continuous mixing of the pulp and enzyme throughout the reaction time. The Bernier et al. process is illustrated with treatment times of a day or more. Bernier et al. states that its purified endo-xylanase has a "pH of 5.2." The invention uses a cellulase activity (about 300 EGU/g or greater) so it is a true enzyme mixture. The cellulase/xylanase mixture of the invention preferably is produced/expressed by the microorganism Trichoderma (although other cellulase/xylanase mixtures having substantial cellulase activity obtained from other microorganism sources can be used). The microorganism sources of the cellulase/xylanase mixtures useful in the invention have cellulase-positive activity. The invention process preferably initially mixes the pulp and enzyme mixture and then lets the admixture stand. The invention process preferably uses a reaction time of 1 to 2 hours. The invention process preferably uses a pH of 6 to 8.
Celluclast 1.5 L is a liquid cellulase preparation made by submerged fermentation of a selected strain of the fungi Trichoderma Reesi. It is a product of Novo Nordisk A/S, Bioindustrial Group, Enzyme Process Division, of Denmark. A product brochure by such company states that the optimum working pH is 4.5 to 6.0.
SP 476 is an endo-1.4-beta-D-glucanase (EC 3.2.1.4) preparation produced by submerged fermentation of a selected strain of fungal origin. It is a product of Novo Nordisk Bioindustrials Inc., Enzyme Process Division, of Connecticut. A product brochure by such company states that the maximum activity in the pH range is 5.0 to 9.0.
EXAMPLE 1
Laboratory scale work was performed on vessel elements that were separated from unbleached hardwood fiber and treated with a cellulase/xylanase enzyme mixture (SP 342). Both treated and untreated vessels were analyzed by Fourier Transform Infrared Analysis (FTIR) to determine if the enzymes had any effect on the vessels. The spectra received from the analysis showed that the enzymes were breaking --OH bonds (i.e., breaking glycolytic ester linkages, R 1 --O--R 2 linkages) and forming --CONH 2 bonds. The analysis also showed that aromatic rings may have been broken by enzyme treatment. These changes in the chemical structure of the vessels will weaken the wall strength and make the vessels more susceptible to breaking under mechanical forces, such as, normal mill refining. The enzymes did not actually break the vessels at this point, but apparently weakened the wall integrity.
EXAMPLE 2
Hardwood brownstock pulp was treated with two different enzymes and enzyme mixtures at varying levels prior to refining. A purified cellulase (Celluclast 1.5 L) and a cellulase/xylanase mixture No. 1 (SP 342) were used separately under specific pH control (cellulase: 4.6, and the cellulase/xylanase mixture No. 1: 6.0) for one hour at 130° F. with no intermittent mixing throughout the reaction. Thorough mixing took place at the initiation of the reaction, but no mixing was used throughout the remainder of the reaction time. After enzyme treatment, the pulps were refined by a PFI Mill to a standard 35° S--R freeness and Tappi handsheets prepared. The handsheets were tested by an IGT testing instrument by IGT/Reprotest B.V. This instrument allows vessel picking to be observed and quantified. The results are set out in the following table:
TABLE 1______________________________________ Average Vessel Standard %Trial.sup.1 pH Picks/cm.sup.2 Deviation Reduction______________________________________Control -- 4.0 0.8 0Cellulase, 0.01% 4.6 5.8 0.5 0Cellulase, 0.10% 4.6 3.5 0.6 12Cellulase/xylanase 6.0 3.2 0.9 40mixture #1, 0.01%Cellulase/xylanase 6.0 1.3 0.5 68mixture #1, 0.10%______________________________________ Note: .sup.1 Weight percent of enzyme or enzyme mixture, based on the weight of the hardwood brownstock pulp, assuming 100 percent activity of the enzymes.
EXAMPLE 3
Hardwood brownstock pulp was treated with several different enzymes and mixtures at varying levels prior to refining. The same purified cellulase (Celluclast 1.5 L) in Example 2 and the cellulase/xylanase mixture No. 1 (SP 342) from Example 2, a glucanase (SP 476), and a cellulase/xylanase mixture No. 2 (Pulpzyme HA) were used separately under specific pH (cellulase: 5.5, cellulase/xylanase mixture No. 1: 6.0, glucanase: 7.0, and cellulase/xylanase mixture No. 2: 7.0) control for one hour at 130° F. with no intermittent mixing throughout the reaction. Thorough mixing took place at the initiation of the reaction, but no mixing was used throughout the remainder of the reaction time. After enzyme treatment, the pulps were refined by a PFI Mill to a standard 35° S--R freeness and Tappi handsheets prepared. The handsheets were tested by an IGT testing instrument by TGT/Reprotest B.V. This instrument allows vessel picking to be observed and quantified. The results are set out in the following table.
TABLE 2______________________________________ Average Vessel StandardTrial Picks/cm.sup.2 Deviation % Reduction______________________________________Control 4.8 0.8 0Cellulase #1 4.3 0.5 10Glucanase 2.2 0.4 54Cellulase/xylanase 1.5 0.6 69mixture #2Cellulase/xylanase 2.2 0.8 54mixture #1______________________________________
EXAMPLE 4
Hardwood brownstock pulp was treated with several different enzymes and mixtures at varying levels prior to refining. The cellulase/xylanase mixture No. 1 (SP 342), the glucanase (SP 476), and the cellulase/xylanase mixture No. 2 (Pulpzyme HA) were used separately under specific pH (cellulase/xylanase mixture No. 1: 6.0, glucanase: 7.0, and cellulase/xylanase mixture No. 2: 7.0) control for one hour at 130° F. with no intermittent mixing throughout the reaction. Thorough mixing took place at the initiation of the reaction, but no mixing was used throughout the remainder of the reaction time. After enzyme treatment, the pulps were bleached to approximately an 83 GE or TAPPI brightness. The bleached pulps were refined by a PFI Mill to a standard 35° S--R freeness and Tappi handsheet prepared. The handsheets were tested by an IGT testing instrument by IGT/Reprotest B.V. This instrument allows vessel picking to be observed and quantified. The results are set out in the following table:
TABLE 3______________________________________ Average Vessel StandardTrial Picks/cm.sup.2 Deviation % Reduction______________________________________Control 4.0 0.8 0Cellulase/xylanase 2.0 0.8 50mixture #1Glucanase 2.0 0.5 45Cellulase/xylanase 1.2 0.9 70mixture #2______________________________________
All enzyme doses in Examples 3 and 4 were 0.10 percent on O.D. (oven dry) fiber.
EXAMPLE 5
The main objective of this mill trial was to duplicate the laboratory work using Pulpzyme HA, a cellulase/xylanase enzyme mixture, to reduce hardwood vessel picking without substantially reducing fiber strength. Specifically, the goal was to reduce vessel picking by a minimum of 55 percent.
Pulpzyme HA was added in dosages of 0.9 to 1.4 kg/ton of pulp to the brownstock hardwood pulp prior to high density storage. Sulfuric acid was added to maintain a pH of 7.0. Final stage pulp was sampled every four hours for a composite sample with grab samples taken three times a day. Fully bleached pulp samples were refined to 35° S--R by the refining mill. Vessel picking and strength tests were determined. The actual trial period was eight days (seven days of enzyme addition, a one day control (no enzyme addition) interval, followed by one day of enzyme addition).
FIG. 1 describes the results of vessel picking from samples taken during the trial. Some of the samples were daily composites and some were grab samples. Trial periods consistently reduced vessel picking by 75 to 100 percent. Paper machine and off machine coater data were also studied during the trial. Shallow picking (vessel picking) was reduced by 50 to 73 percent during the trial versus historical data.
Another quality of the pulp noticed during testing was that enzyme treated vessels are substantially smaller than untreated. This could affect the paper quality in two ways. The smaller vessels have less surface area than the larger ones. When ink is applied to the sheet, the smaller vessels and the ink may not produce enough tack to pick from the sheet. Secondly, the smaller vessels may also have a tendency to be imbedded further into the sheet than larger vessels, thus preventing surface picking.
One concern in using Pulpzyme HA is reducing pulp strength. No significant reductions were seen in pulp viscosity, tear, burst, breaking length or apparent density due to Pulpzyme HA use.
The Pulpzyme HA mill trial reinforced the results seen in the laboratory vessel pick reduction studies. Pulpzyme HA reduced mill vessel picking and possibly paper machine vessel picking by 75 to 100 percent. While reductions in vessel picking were consistently observed, no reductions in pulp viscosity or pulp strength were produced. Also, Pulpzyme HA addition may have also reduced combined first and second stage filtrate colors by as much as 15 percent.
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The process uses a mixture of cellulases and xylanases to chemically change the hardwood vessel elements, rendering them susceptible to breaking under normal mill refining, thus not requiring any additional refining equipment. The process involves treating hardwood brownstock (unbleached) pulp with a cellulase/xylanase mixture. The use of a pure cellulase enzyme is excluded.
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This is a continuation of copending application Ser. No. 07/259,650 filed on Oct. 19, 1988, now abandoned.
BACKGROUND AND SUMMARY OF THE INVENTION
Documentation is useful for manufacturing in the areas of training and reference. High quality documentation provides recognizable depictions of articles used in manufacture and clear instructions as to how the article is to be utilized. Typically, high quality documentation which include clear pictures of articles have been provided only through the use of "hard copy" or printed materials. High quality documentation with accurate pictorial representations of articles used in manufacture are not generally electronically available for display upon a monitor.
SUMMARY OF THE INVENTION
In accordance with the preferred embodiment of the present invention a method for the provision of electronic documentation to a manufacturing technician is presented. A plurality of digital images of an article used in manufacturing are created. The article may be, for example a printed circuit board. Once created the digital images are scaled and combined to form a display. Each digital image is displayed in a separate section of the display. For example, one section may include an image of the printed circuit board scaled such that it is possible to determine the orientation of the printed circuit board in a manufacturing tray. Another second may include a close up of a label on the printed circuit board. Another section may include an image of the printed circuit board scaled such that the manufacturing technician is able to determined the relative position of a plurality of labels on the printed circuit board.
Text is then added to the display which further describes to the manufacturing technician what he is viewing. The display is then stored with the added text and displayed to the manufacturing technician during manufacture. For example, a computer program which oversees manufacture of circuit boards may automatically retrieve the digital image and display the digital image to the manufacturing technician upon the manufacture of the circuit board reaching a predetermined stage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of hardware a digital image documentation system in accordance with the preferred embodiment of the present invention.
FIG. 2 is a block diagram of software used for the digital image documentation system shown in FIG. 1.
FIGS. 3A-3C show the structure and hierarchy a first program within the software shown in FIG. 2.
FIG. 4 shows the structure and hierarchy of a second program within the software shown in FIG. 2.
FIG. 5 shows a camera creating digital images of a printed circuit board in accordance with the preferred embodiment of the present invention.
FIG. 6 shows a screen which displays a first example of data generated by the documentation shown in FIG. 1.
FIG. 7 shows a screen which displays a second example of data generated by the documentation shown in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, hardware for a create system which creates documentation is shown to consist of a camera 104, a personal computer 103, a RGB (red, green and blue) monitor 101, and a disk drive 102. Camera 104 may be, for example, an RGB camera sold by Sony Corporation of Japan. Disk drive 102 may be, for example, a 142 megabyte hard disk drive such as those available form Hewlett Packard Company, a California Corporation having a business address of 3000 Hanover Street, Palo Alto, Calif. 94304.
Personal computer 103 may be, for example, a Vectra personal computer available from Hewlett Packard Company. Personal computer 103 contains a raster graphics adapter board such as a Truevison Advanced Raster Graphics Adapter 16 (TARGA 16) board available from AT&T Corporation. A TARGA 16 board comes with 512 kilobytes of random access memory (RAM) and supports a spatial resolution of 512 by 400 pixels. Personal computer 103 is also equipped with a keyboard 121, a mouse 122 and an enhanced graphics adaptor (EGA) used to drive an enhanced graphics display (EGD) monitor 120.
Hardware for a display system which displays documentation created by the create system is shown to consist of a host computer 105, a disk drive 106, a front-end computer 107, a personal computer 108, a disk drive 109, a terminal 110, an RGB monitor 111, a terminal 112 and an RGB monitor 113. Host computer 105 is used to transfer information from the create system to the display system, and to manage files in the display system. Host computer 105 is also used for a variety of tasks pertaining to manufacturing not related to the present invention. Host computer 150 may be, for example, an HP1000 series A900 computer available from Hewlett Packard Company.
Front-end computer 107 is used by manufacturing technicians as a front end to host computer 105. Front-end computer 107 may be, for example, an HP1000 series A600 computer available from Hewlett Packard Company. Front-end computer 107 is used to provide processing capability for two manufacturing workstations and is used for control of other manufacturing equipment. The first of the two manufacturing workstation logically includes terminal 110 and RGB monitor 111. The second manufacturing workstation logically includes terminal 112 and RGB monitor 113.
Disk drive 106 is used by host computer 105 for general purposes. Disk drive 109 may be, for example, a 142 megabyte hard disk drive available from Hewlett Packard Company. Personal computer 108 may be, for example, a Vectra personal computer available from Hewlett Packard Company. Personal computer 108 contains two raster graphics adaptor boards--for example TARGA 16 boards--one used to generate the display on RGB monitor 111 and one sued to generate the display on RGB monitor 113.
Software programs for the digital image documentation system (DIDS) are shown in FIG. 2. Within personal computer 103 runs a main program 202 and a transport program 201. Transport program 201 is used to transport information from personal computer 103 to host computer 105. Program 201 may be, for example, AdvanceLink available from Hewlett Packard Company.
Main program 202--called DIDS.EXE--has three main functions. Main program 202: (1) controls the TARGA 16 board within personal computer 103; (2) controls the EGA and thus the display on EGD monitor 120; and (3) controls input devices, i.e., mouse 122 and keyboard 121. Main program 202 may be roughly broken into routines within four levels.
The first level is the routines which interface directly to hardware, for instance, routines which interface with the TARGA 16 board, the EGA, mouse 122, keyboard 101 and the file system within disk drive 102.
The second level contains routines which perform graphics and image synthesis on images stored in the TARGA 16 board. These routines include primitives for line drawing, area filling, raster scaling, color correction and etc.
The third level routines interface to the user. These routines provide a user with direct manipulation and function key control for performing graphics operations provided by the second level routines. The third level routines will allow users to perform file management of stored images and other general level application control.
The fourth level provides the integration of the other three levels in order to produce the final application. Routines at this level provide functions like, for example, macro creation and the ability to record a set of graphics operations to a file for use as a standard template package.
FIG. 3 shows a hierarchic overview of main program 202. Upon start-up, initialization routines 301 initialize the TARGA 16 board and the EGA. Get user input routine 302 then waits for a user to input information from either keyboard 121 or mouse 122. Main program 202 parses the information received from user to determine whether (1) the user desires some on-line assistance, (2) the user wishes to perform file management, or (3) the user wishes to create or modify documentation.
If the user requests on-line assistance, help routines 304 are called which provide on-line assistance to the user. If the user requests to manage files, file management routines 305 are called. File management routines 305 call other routines in response to user requests. Directory operations routines 322 are used to perform function on the level of directories. File operations routines 323 are used to perform functions on files. Disk operations routines 324 are used to manage disk drive 102. Help routines 325 are used to provide on-line assistance to a user in the area of file management.
If a user request to create or modify documentation, create/modify documentation routines 303 are called. Create/modify documentation routines 303 call other routines in response to user requests. Load/save documentation routines 306 are used to store documentation to disk drive 102 and to load documentation from disk drive 102. Video camera input routines 308 are used to obtain images from video camera 104. Annotate documentation routines 307 are used to annotate images obtained by video camera input routines 308. Help routines 309 are used to provide on-line assistance to a user in the area of documentation creation and modification.
Video camera input routines 308 call other routines in response to user requests. Video camera control routines 314 are used to control input from video camera 104. Select window routines 313 are used to select a predefined area of a screen (i.e., select a window). Cancel routines 315 are used to halt the processing of images form video camera 104.
Video camera control routines 314 call other routines in response to user requests. Digitize video signal routines 319 are used to digitize video signals received from video cameras 104. Live video routines 318 are used to allow real-time viewing of images from video camera 104 through the TARGA 16 board. Such viewing allows for various adjustments to be made before an image is digitized. Scale captured frame routines 320 are used to scale the digitized images from video camera 104. Live video routines 318 and digitize video signal routines 319 calls routines within video control TARGA library 321. These routines are used in the actual control of the TARGA 16 board. The TARGA 16 board, in turn is electrically connected to video camera 104 and is the interface through which personal computer 103 communicate with video camera 104.
Annotate documentation routines 307 uses other routines, in response to user requests, to annotate images obtained and digitized by video camera input routines 308., Set graphics attributes routines 310 are used to change graphics attributes such as line width, color of fill, font size, fill area, text colors and etc. Load/Save graphics macros 312 are used to store graphics macros in disk drive 102 and to retrieve a particular graphics macro from disk drive 102 when a user wishes to execute that graphics macro. Draw lines, text and boxes routines 311 are used in the actual placement of text and graphics over images generated by video camera input routines 307. Draw lines, text and boxes routines 311 through user input routines 316, receive user direction through user manipulations of keyboard 121 and mouse 122. Draw lines, text and boxes routines 311 also utilize routines within a two-dimensional graphics TARGA library 317 in the placement of graphics over images digitized and stored in the TARGA 16 board.
In the preferred embodiment, files residing on disk drive 102, may be transferred to disk drive 109 through serial interface 114. Serial interface 114, is, for example, RS232 cable. Transport program 201 transfers files from disk 102 to host computer 105. Files may then be transferred to personal computer 108 with the use of a file management program 203 and a file management message program 204. File management program 203 provides a user with the ability, from host computer 105, to remotely manage files on disk drive 109. File management message program serves as a conduit for file management instructions originating on host computer 105 and destined for execution on personal computer 108. Alternately, files might be transferred from personal computer 103 to personal computer 108 with the use of floppy disks.
A process control program 205 and a process control program 206 reside on front-end computer 107. Process control program 205 interacts with terminal 110 and process control program 206 interacts with terminal 112. Process control programs 205 and 206 oversee manufacture of printed circuit boards. For example, if a operator is using terminal 110 and is ready to manufacture a printed circuit board, the operator will, for example, identify to process control program 205 the type of printed circuit board he is manufacturing, the quantity to be manufactured etc. This information will be used to update a data base. Process control program 205 then supplies the operator with information on the manufacturing steps to be performed.
A document server program 207--called SEND.EXE--resides in personal computer 108, as shown in FIG. 2. Document server program controls hard disk 109, two TARGA 16 boards and a serial port. Document server program 207 receives file management commands from file management message program 204 and receives requests for the display of images on RGB monitor 111 or RGB monitor 113 from process control program 205 and process control program 206, respectively. As directed by these commands, server program 207 manipulates files within hard disk 109, controls the TARGA 16 boards within personal computer 108 and displays information on RGB monitor 111 or RGB monitor 113.
FIG. 4 shows a hierarchic overview of document server program 207. Upon start up, initialization routines 401 initialize a serial port in personal computer 108. Once initiated, get command routines 402 wait for commands from front-end computer 107 to be sent through the initialized serial port. Once a command is received parse command routines 403 parse the command.
If the command is a request to display a document, display document routines 404 process the command. Initialize routines 405 initializes the TARGA 16 board used to control RGB monitor 111, if the command requests a display on RGB monitor 111, and initialize routines 405 initialize the TARGA 16 board used to control RGB monitor 113, if the command requests a display on RGB monitor 113. Load documentation routines 406 loads documentation into the initialized TARGA 16 board for display on the selected RGB monitor. Acknowledge routines 407 notifies front-end computer 107 that the document has been displayed on the selected RGB monitor.
If the command is a request for file management file management routines 408 process the command. When the command requests an operation to be performed on a file directory, directory operation routines 409 perform the requested directory operation. Acknowledge routines 410 then notifies host computer 405 through front-end computer 107 that the requested directory operation has been performed.
When the command requests a directory listing, directory listing routines 411 process the command. Directory listing routines 411 uses send size of data routines 412 to send to front-end computer 107 the amount of data to be sent. Wait for acknowledge routines wait for front-end computer 107 to acknowledge that it is ready to receive the data. Transfer data routines 414 then transfers the data.
For example, documentation which displays to a manufacturing technician the correct placement of labels may be created as shown in FIG. 5. On a prototype circuit board 504 is placed a label 505 and a label 506, as shown. Label 506 contains a date code identifying the revision of circuit board 504. Label 505 contains warranty information. Using camera 104, various pictures are taken of circuit board 504. For example a picture may be taken showing the orientation of circuit board 504 in a manufacturing tray. A picture may be taken showing the position and orientation of label 505 and label 506 on circuit board 505. A picture may be taken showing a close-up of label 505 and label 506. The pictures are digitally stored on disk 102. Also, using main program 202, boxes, text and etc., may be added to the digital images of the pictures in order to give additional information to a manufacturing technician who will utilize the pictures.
Once the images are stored in disk drive 102 they may be transported to disk drive 109, either by hand-carrying a floppy disk from personal computer 121 to personal computer 108, or by electronic transport from personal computer 103, through host computer 105, through front-end computer 107 to personal computer 108.
Once stored in disk drive 103, the images are available to be displayed on RGB monitor 111 or RGB monitor 113. For example, a certain stage of processing, process control program 205 may request personal computer 108 to display an image on RGB monitor 111. Similarly, process control program 206 may request personal computer 108 to display an image on RGB monitor 113. In the case of labels, the image may be displayed immediately upon a manufacturing technician indicating to the process control program the type of circuit board which is to be manufactured.
In FIG. 6 is shown an example of how printed circuit board 504 may be displayed on a screen 500 of RGB monitor 111. In a section 502 of screen 500, an image of circuit board 504 is shown. Within screen section 502, the image of circuit board 504 is scaled such that it is possible to determine the orientation of printed circuit board 504 in a manufacturing tray 510. In a section 501 of screen 500 an image of circuit board 504 is shown scaled so that the position and orientation of label 505 and label 506 is shown. Overlaying a portion of screen section 501 and a portion of screen section 502 is a box 50 which includes text informing a manufacturing technician that the image being shown in screen section 501 and screen section 502 is the side of circuit board 504 upon which components are placed.
In a section 503 of screen 500 an image is shown which is a close up of label 505 and label 506. Box 508 overlays a portion of screen section 503. Text within box 508 and a line 511 extending from box 508 to label 506 indicate to a manufacturing technician that label 506 contains the date code which identifies the revision of circuit board 504. Box 509 also overlays a portion of screen section 503. Text within box 509 and a line 512 extending from box 509 to label 505 indicate to a manufacturing technician that label 505 contains warranty information.
If two labels are placed on a circuit board at a sufficient distance apart so that it is impossible to show a close up image of both labels simultaneously on the circuit board, screen 50 may be additionally sub-divided so that there is a separate screen section for each label. For example, in FIG. 7 are shown images of a printed circuit board 604 with a label 605 and 606 placed at widely separated portions of printed circuit board 605. In a section 602 of screen 500, an image of circuit board 604 is shown. Within screen section 602, the image of circuit board 604 is scaled such that it is possible to determine the orientation of printed circuit board 604 in a manufacturing tray 610. In a section 601 of screen 500 an image of circuit board 604 is shown scaled so that the position and orientation of label 605 and lablel 606 is shown. Overlaying a portion of screen section 601 and a portion of screen section 602 is a box 607 which includes text informing a manufacturing technician that the image being shown in screen section 601 and screen section 602 is the side of circuit board 604 upon which components are placed.
In a section 603 of screen 500 an image is shown which is a close up of label 605. In a section 604 of screen 500 an image is shown which is a close up of label 606. Box 608 overlays a portion of screen section 603 and a portion of screen section 604. Text within box 608 and a line 611 extending from box 608 to label 606 indicate to a manufacturing technician that label 606 contains the date code which identifies the revision of circuit board 604. Box 609 also overlays a portion of screen section 603 and a portion of screen section 604. Text within box 609 and a line 612 extending from box 609 to label 605 indicate to a manufacturing technician that label 605 contains warranty information.
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A plurality of digital images of an article used in manufacturing are created. Once created the digital images are scaled and combined to form a display. Each digital image is displayed in a separate section of the display. For example, one section may include an image of the printed circuit board scaled such that it is possible to determine the orientation of the printed circuit board in a manufacturing tray. Another section may include a close up of a label on the printed circuit board. Another section may include an image of the printed circuit board scaled such that the manufacturing technician is able to determine the relative position of a plurality of labels on the printed circuit board. Text is then added to the display which further describes to the manufacturing technician what he is viewing. The display is then stored with the added text and displayed to the manufacturing technician during manufacture. A computer program which oversees manufacture of circuit boards may automatically retrieve the digital image and display the digital image to the manufacturing technician upon the manufacture of the circuit board reaching a predetermined stage.
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FIELD OF THE INVENTION
The present invention relates generally to the field of instruments for providing access during surgical procedures, and more particularly relates to retractor instruments for enabling access to a surgical site and shielding tissue during a surgical procedure.
BACKGROUND
Surgical procedures have generally become less disruptive to peripheral tissues as surgical techniques have progressed. Traditional surgical procedures used to treat tissues through incisions have often been very disruptive to peripheral tissues. Such procedures may include incisions through the skin, muscles, vessels, nerves, and other tissues, and may include long and deep incisions. Traditional procedures may include retractors that are either larger than is necessary to effectively perform a procedure or that are cumbersome to operated and therefore require longer periods of retraction than is necessary to perform a procedure. Traditional procedures, consequently, may lead to more trauma to peripheral tissues, more pain, and more lengthy and expensive recoveries. Cumbersome equipment that results in longer operating times may also lead to greater hospital, surgical staff, and physician expenses.
Modern surgical instruments and techniques have enabled less invasive and more expedient access to surgical sites. By way of non-limiting example, less invasive surgical instruments and techniques have been used in spinal surgery to separate and progressively dilate and retract tissues rather than to sever and retract the tissues. Developments in less invasive surgical instruments and methods have been significant, but there remains a need for enhancement of instruments and methods. Enhanced instruments and methods may include features that enable one or more of improvements to the efficiency, speed, access capability, or size of an instrument used in one or more methods.
Although particular embodiments of the surgical instruments and methods are described herein in association with particular spinal surgical procedures and surgical approaches, certain instruments and methods may be equally effective in other surgical procedures in the spine or in other areas of the anatomy.
SUMMARY
One embodiment of the invention is a surgical access instrument. The surgical access instrument may include a flexarm retractor with a base, a first retractor appendage coupled to the base wherein the first retractor appendage has a length and lateral sides along its length, a flexible arm coupled to the base at a proximal end of the flexible arm such that a distal end of the flexible arm is movable relative to the base, and a second retractor appendage coupled to the flexible arm at the distal end of the flexible arm wherein the first retractor appendage has a length and lateral sides along its length. The surgical access instrument may also include a transverse retractor coupled to the base of the flexarm retractor. The transverse retractor may include an assembly with a frame, a threaded shaft rotatably coupled with the frame, a first carriage coupled with the threaded shaft that is configured to translate along the threaded shaft when the shaft is turned, and a second carriage coupled with the threaded shaft that is configured to translate along the threaded shaft when the shaft is turned. Embodiments of the transverse retractor may also include a first transverse retractor appendage coupled with the first carriage, wherein the first retractor appendage has a length and lateral sides along its length, and a second transverse retractor appendage coupled with the second carriage, wherein the second retractor appendage has a length and lateral sides along its length. In some embodiments, the first retractor appendage, the second retractor appendage, the first transverse retractor appendage, and the second transverse retractor appendage are configured to be aligned substantially along their respective lengths and an access portal to the surgical site is formed among a lateral side of the first retractor appendage, a lateral side of the second retractor appendage, a lateral side of the first transverse retractor appendage, and a lateral side of the second transverse retractor appendage.
An embodiment of the invention is a flexible retractor for holding back tissue near a surgical site. The flexible retractor may include a base, a first retractor appendage coupled to the base wherein the first retractor appendage has a length and lateral sides along its length, a flexible arm coupled to the base at a proximal end of the flexible arm such that a distal end of the flexible arm is movable relative to the base, and a second retractor appendage coupled to the flexible arm at the distal end of the flexible arm wherein the first retractor appendage has a length and lateral sides along its length. The first and second retractor appendages may be aligned substantially along their respective lengths and an access portal to the surgical site is formed between a lateral side of the first retractor appendage and a lateral side of the second retractor appendage.
Still another embodiment of the invention is a transverse retractor. Embodiments of the transverse retractor include an assembly with a frame, a threaded shaft rotatably coupled with the frame, a first carriage coupled with the threaded shaft that is configured to translate along the threaded shaft when the shaft is turned, and a second carriage coupled with the threaded shaft that is configured to translate along the threaded shaft when the shaft is turned. Embodiments of the transverse retractor include a first transverse retractor appendage coupled with the first carriage, wherein the first retractor appendage has a length and lateral sides along its length, and a second transverse retractor appendage coupled with the second carriage, wherein the second retractor appendage has a length and lateral sides along its length. In some embodiments, a first portion of the threaded shaft that is coupled with the first carriage has right-hand threads and a second portion of the threaded shaft that is coupled with the second carriage has left-hand threads such that rotation of the shaft in a first rotational direction causes the first and second transverse retractor appendages to move together simultaneously and rotation of the shaft in a second rotational direction opposite from the first rotational direction causes the first and second transverse retractor appendages to move apart simultaneously.
Another embodiment of the invention is a method of creating an access portal to a surgical site. The method may include introducing a first retractor into the surgical site such that the retractor is in a position to separate tissues along a first axis, and introducing a flexarm retractor into the surgical site such that the flexarm retractor is in a position to separate tissues along a second axis that is substantially transverse to the first axis. The flexarm retractor of some embodiments may include a base, a first retractor appendage coupled to the base, a flexible arm coupled to the base at a proximal end of the flexible arm, and a second retractor appendage coupled to the flexible arm at a distal end of the flexible arm. Method embodiments may also include coupling the flexarm retractor with the first retractor, separating the first retractor appendage from the second retractor appendage to create an access portal to the surgical site, and actuating a control on the flexarm retractor to stiffen the flexible arm to fix the second retractor appendage in a desired location.
Yet another embodiment of the invention is a method of creating an access portal to a surgical site. The method includes introducing a retractor with two appendages into the surgical site such that the retractor is in a position to separate tissues along an axis. The retractor may include mechanisms for switching from a first state where one rotational control moves both appendages simultaneously together or apart along the axis to a second state where the one rotational control moves only one of the appendages along the axis.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a surgical access instrument.
FIG. 2 is a perspective view of the flexarm retractor portion of the surgical access instrument of FIG. 1 .
FIG. 3 is a perspective view of the flexarm retractor portion of the surgical access instrument of FIG. 1 with certain components removed.
FIG. 4 is a perspective view of the flexarm retractor portion of the surgical access instrument of FIG. 1 with certain components removed.
FIG. 5 is a perspective view of the flexarm retractor portion of the surgical access instrument of FIG. 1 with certain components removed.
FIG. 6 is a perspective view of the transverse retractor portion of the surgical access instrument of FIG. 1 .
FIG. 7 is a perspective view of the transverse retractor portion of the surgical access instrument of FIG. 1 .
FIG. 8 is a perspective view of the transverse retractor portion of the surgical access instrument of FIG. 1 .
FIG. 9 is a perspective view of the transverse retractor portion as illustrated in FIG. 8 with portions of the transverse retractor cut away to illustrate additional components.
FIG. 10 is an elevation view of internal components of the transverse retractor with a central shaft rotationally engaged with two portions of the threaded shaft.
FIG. 11 is an elevation view of internal components of the transverse retractor with a central shaft rotationally engaged with one portion of the threaded shaft and rotationally disengaged with another portion of the threaded shaft.
FIG. 12 is a perspective view of a surgical access instrument.
DETAILED DESCRIPTION
An embodiment of a surgical access instrument 1 is illustrated in FIG. 1 . The illustrated surgical access instrument 1 includes a flexarm retractor 10 couple with a transverse retractor 30 . An embodiment of the flexarm retractor 10 will be described in more detail with reference to FIGS. 1-5 . An embodiment of the transverse retractor will be described in more detail with reference to FIGS. 6-11 .
The flexarm retractor 10 illustrated includes a base 11 . As most clearly illustrated in FIG. 4 , the base 11 of the embodiment shown has a C-shaped body 12 and a rack 13 . The C-shaped body 12 is configured to couple with the transverse retractor 30 . The coupling between the C-shaped body 12 and the transverse retractor 30 may be an interference fit where the inside of the C-shaped body 12 is pressed against the transverse retractor 30 . An interference fit may be adequate to maintain the integrity of the surgical access instrument 1 because forces generated by interactions among components of the surgical access instrument 1 , and the retracted tissues may also serve to stabilize the flexarm retractor 10 relative to the transverse retractor 30 . The C-shaped body 12 is prevented by the extents of the C-shape from translating up and down relative to the transverse retractor 30 . Rotational movement allowed between the C-shaped body 12 and the transverse retractor may be advantageous in surgical procedures where the transverse retractor 30 is first placed in a surgical site, and then the flexarm retractor 10 is added to the construct to complete the surgical access instrument 1 . For example, when the transverse retractor 30 is in place in a surgical site, the C-shaped body 12 may be placed against the transverse retractor 30 with one or both of a first retractor appendage 21 and a second retractor appendage 22 rotated up and out of the surgical site. The flexarm retractor may then be rotated about the C-shaped body 12 to insert the first retractor appendage 21 and the second retractor appendage 22 into the surgical site in a desired location.
The coupling between the C-shaped body 12 and the transverse retractor 30 may also be a fixed or pinned coupling in some embodiments. By way of example and without limitation, the coupling may be achieved by welding, may include an adhesive, may include a fastener such as a screw, pin, bolt, rivet, or the like, or may be accomplished through any other effective mechanism.
The rack 13 of the embodiment illustrated in FIGS. 1-5 provides a connection between the base 11 and the first retractor appendage 21 through a bar 23 . The bar 23 extends away for the base 11 and terminates at the first retractor appendage 21 . The bar 23 shown is slideably coupled to the base 11 such that the first retractor appendage 21 may be moved closer to or more distant from the surgical site relative to the base 11 by sliding the bar 23 relative to the base 11 . A pinion assembly 24 couples with the rack 13 . The pinion assembly 24 includes a catch 25 that provides a releasable connection between the pinion assembly 24 and one or more teeth 14 of the rack 13 . The combination of the teeth 14 and the catch 25 allows for movement of the rack 13 relative to the pinion assembly 24 to be selectively maintained at a desired position. In some embodiments, the catch 25 is biased toward engagement with the teeth 14 such that pressure on a lever end 26 of the catch 25 is required to disengage the catch 25 from the teeth 14 . The teeth 14 may be formed such that the pinion assembly 24 ratchets in either direction relative to the base 11 . By these or other effective mechanisms, the first retractor appendage 21 may be switched between a free state and a locked state relative to the base 11 . The first retractor appendage 21 may also be connected directly to the base 11 in some embodiments without the intervening bar 23 as illustrated. This connection may be fixed or may be releasable.
The pinion assembly 24 also includes a spindle 27 in some embodiments. The spindle 27 includes one or more cogs (not shown) around a perimeter of the spindle 27 that engage with the teeth 14 of the rack 13 . By turning the spindle 27 , the cogs may be advanced along the teeth 14 to move the rack 13 relative to the pinion assembly 24 . The spindle 27 may further include a wing nut, internal hex, external hex, or other opening or component useful in applying torque to the spindle 27 to turn the spindle 27 and move the rack 13 relative to the pinion assembly 24 .
As illustrated in FIG. 5 , the first retractor appendage 21 includes a length extending along its longitudinal axis and lateral sides 29 along its length. The first retractor appendage 21 illustrated has a radius or curve about its longitudinal axis. The curve of the illustrated embodiment has a relatively large radius, but may be significantly reduced in some designs of the invention. For example, the radius may be small to produce essentially a section of a tube approximately the same diameter as the width of the retractor appendage illustrated in FIG. 5 . In other embodiments, the retractor appendage may be substantially flat or planar to form a substantially flat blade.
As illustrated in FIGS. 1-3 , a flexible arm 15 is coupled to the base 11 at a proximal end 16 of the flexible arm 15 . A distal end 17 of the flexible arm 15 is movable relative to the base 11 . In the embodiment shown, multiple cannulated joints 18 interconnect with one another along a curvilinear path to form a continuous cannulated member. In some embodiments, the multiple cannulated joints 18 may interconnect with one another along a linear path. A tensile element 19 is disposed through the cannula of the multiple cannulated joints 18 . Several of the cannulated joints 18 are removed from FIG. 3 to show an end of one of the cannulated joints 18 and the tensile element 19 . The flexible arm 15 of the illustrated embodiment may have a free state and a locked state relative to the base 11 . The free state may exist when the tensile element 19 is loosened and some or all of the cannulated joints 18 are rotatable relative to one another. Another example of a free state is where tension is applied to the tensile element 19 to create some resistance among the cannulated joints 18 , but adequate lateral pressure to the flexible arm will result in movement of the flexible arm 15 relative to the base 11 . A locked state may exist where significant tension is applied to the tensile element 19 to prevent rotation or movement of the cannulated joints 18 relative to one another. In some embodiments, the second retractor appendage 22 may separately or in conjunction with the flexible arm 15 include a free state and a locked state as a result of tension applied to the tensile element 19 or by other effective mechanisms.
All of the cannulated joints 18 have been removed from the tensile element 19 in the FIG. 5 illustration to show how the tensile element 19 of the embodiment interacts with the bar 23 . The tensile element 19 shown fits into a notch 28 in the bar 23 to accommodate movement of the rack 13 next to the bar 23 . The tensile element 19 of the embodiment shown in FIGS. 1-5 is threaded through a hole 89 ( FIG. 4 ) in the base 11 and fixed to the bar 23 . Consequently, movement of the bar 23 relative to the base 11 by turning of the spindle 27 results in tensioning of the tensile element 19 and locking of the flexible arm 15 . Therefore, by common activation of this control, the first retractor appendage 21 , the flexible arm 15 , and the second retractor appendage 22 may all be switched between a free state and a locked state relative to the base 11 . In other embodiments, the bar 23 is independently movable relative to the base 11 and the tensile element 19 is separately able to be tensioned. For example, and without limitation, the notch 28 may pass through the bar 23 in some embodiments, and the tensile element 19 may include a separate control for tightening and loosening the tensile element 19 , and therefore the flexible arm 15 . In such an embodiment, turning of the spindle 27 results in movement of the first retractor appendage 21 relative to the base 11 , and activation of the separate control tightens or loosens the tensile element 19 and the flexible arm 15 .
As shown in FIG. 2 , the second retractor appendage 22 includes a length extending along its longitudinal axis and lateral sides 9 along its length. The second retractor appendage 22 illustrated has a radius or curve about its longitudinal axis. The curve of the illustrated embodiment has a relatively large radius, but may be significantly reduced in some designs of the invention. For example, the radius may be small to produce essentially a section of a tube approximately the same diameter as the width of the retractor appendages illustrated in FIG. 2 . In other embodiments, the retractor appendage may be substantially flat or planar to form a substantially flat blade.
As is shown in combinations of FIGS. 1-3 and 5 , the first retractor appendage 21 and the second retractor appendage 22 are aligned substantially along their respective lengths. An access portal 99 to a surgical site is formed between lateral sides 29 , 9 of the first retractor appendage 21 and the second retractor appendage 22 .
In FIGS. 6-11 , an embodiment of the transverse retractor 30 , including various internal components, is illustrated. The transverse retractor 30 may be coupled to an operating table or other piece of surgical support structure through eyelets 95 . An assembly 35 includes a frame 36 , a threaded shaft 40 rotatably coupled with the frame 36 , a first carriage 31 coupled with the threaded shaft 40 that is configured to translate along the threaded shaft 40 when the threaded shaft 40 is turned, and a second carriage 32 coupled with the threaded shaft 40 that is configured to translate along the threaded shaft 40 when the threaded shaft 40 is turned. The frame 36 illustrated includes a housing 33 , a center strut 34 , a first end cap 37 , and a second end cap 38 . The housing 33 of the illustrated embodiment is coupled to the center strut 34 with fasteners (not shown) that extend through fastener openings 63 ( FIG. 8 ) and fastener openings 64 ( FIGS. 6 and 7 ). The first end cap 37 is coupled to the housing 33 with a fastener 67 , and the second end cap 38 is coupled to the housing 33 with a fastener 68 . In other embodiments, couplings between the components of the frame 36 may be by any effective means, such as but not limited to, welding, application of adhesives, clamping, snap fit components, or with other types of fasteners not specifically listed.
The threaded shaft 40 shown at least in part in each of FIGS. 6-11 couples with and rotates in the frame 36 . In the illustrated embodiment, the frame 36 supports the threaded shaft 40 with rotatable couplings in the first end cap 37 , the second end cap 38 , and at the center strut 34 . One or all of the rotatable couplings may include a bushing, a bearing, or a close tolerance fitting of some operable type. The rotatable couplings may include components made from materials other than the materials of the first end cap 37 , the second end cap 38 , and at the center strut 34 , or may be formed as a part of these components. The threaded shaft 40 , or portions of the shaft, may be restricted from movement along a longitudinal axis of the threaded shaft 40 by fasteners (not shown) that extend through fastener openings 63 and fastener openings 64 , and through grooves 49 ( FIGS. 9-11 ) in the threaded shaft 40 .
The threaded shaft 40 may be a unitary piece in some embodiments. In other embodiments, such as the one shown in more detail in FIGS. 9-11 , the threaded shaft 40 is composed of multiple components and interact to provide additional functionality to the transverse retractor 30 and surgical access instrument 1 . In either type of embodiment, a first portion 41 of the threaded shaft 40 may have right-hand threads that interact with a first carriage 31 , and a second portion 42 of the threaded shaft 40 may have left-hand threads that interact with a second carriage 32 . With such an arrangement, rotation of the threaded shaft 40 in a first rotational direction will result in the first carriage 31 and the second carriage 32 moving together, or toward one another, simultaneously. Rotation of the threaded shaft 40 in a second rotational direction opposite from the first rotational direction will result in the first carriage 31 and the second carriage 32 moving apart simultaneously.
A first receiver 71 for a rotational tool in the first portion 41 of the threaded shaft 40 is shown in FIG. 6 . The first receiver 71 shown is an internal hexagonal shaped opening. Any other functional shape would be acceptable in addition to a hex shape. For example and without limitation, a triangular, square, or other polygonal shape, a star shape, a shape with re-entrant surfaces, and a rounded but non-circular shape would be acceptable. Additionally, in some embodiments an external receiver may be used that extends beyond the surface of the first end cap 37 so that it may be engaged by a rotational tool of any functional shape.
A second receiver for a rotational tool may be embodied in either or both internal receiver 72 and external receiver 73 , as illustrated in FIGS. 7-9 . The internal receiver 72 shown is an internal hexagonal shaped opening. Any other functional shape would be acceptable in addition to a hex shape. For example and without limitation, a triangular, square, or other polygonal shape, a star shape or other shape with re-entrant surfaces, and a rounded but non-circular shape would be acceptable. The external receiver 73 illustrated is a hexagonal shaped component that extends beyond the surface of the second end cap 38 so that it may be engaged by a rotational tool. In addition to hex shaped, the external receiver may be of any functional shape, for example and without limitation, a triangular, square, or other polygonal shape, a shape with re-entrant surfaces, and a rounded but non-circular shape.
The threaded shaft 40 shown in FIGS. 9-11 includes a central shaft 80 on a common axis and disposed through the first portion 41 of the threaded shaft 40 and the second portion 42 of the threaded shaft 40 . In the illustrated embodiment, the first portion 41 and the second portion 42 of the threaded shaft 40 are separate pieces. The central shaft 80 includes a central shaft receiver for accepting a rotational tool used to turn the central shaft 80 . In the embodiment shown, the first receiver 71 and internal receiver 72 serve as central shaft receivers for the central shaft 80 . In some embodiments, the central shaft receiver may extend outside of the coupling of the threaded shaft 40 with the frame 36 to allow particular rotation capabilities or other operation of the central shaft beyond the frame 36 . For the embodiment of FIGS. 9-11 , the central shaft 80 may be translated along the common axis relative to the first portion 41 and the second portion 42 of the threaded shaft 40 .
FIGS. 9 and 10 show the central shaft 80 in a first position, and FIG. 11 shows the central shaft in a second position relative to the first portion 41 and the second portion 42 of the threaded shaft 40 . In the first position, central shaft 80 is rotationally engaged with both the first portion 41 and the second portion 42 of the threaded shaft 40 . In the second position, central shaft 80 is rotationally engaged with the first portion 41 of the threaded shaft 40 but disengaged from the second portion 42 of the threaded shaft 40 .
A detent 39 is shown in FIGS. 9-11 engaged with the central shaft 80 in two locations. In FIGS. 9 and 10 , the detent 39 engages the central shaft 80 in a first indentation 81 . In FIG. 11 , the detent engages the central shaft 80 in a second indentation 82 . The detent 39 is coupled to the housing 33 of the frame 36 . The detent 39 of the embodiment shown is biased toward the central shaft 80 . The central shaft 80 includes a first key 87 for rotationally engaging with the first portion 41 of the threaded shaft 40 and a second key 88 for rotationally engaging with the second portion 42 of the threaded shaft 40 . The first and second keys 87 , 88 may be hexagonal shaped, as illustrated. Additionally, and without limitation, their shape may be a triangular, square, or other polygonal shape, a star shape, a shape with re-entrant surfaces, a rounded but non-circular shape, or any other shape or fitting capable of transferring torque.
In operation, when the detent 39 is in the first indention 81 , the first key 87 is engaged with a like shaped opening in the first threaded portion 41 , and the second key 88 is engaged with a like shaped opening in the second threaded portion 42 . Consequently, turning of any of the first receiver 71 , the internal receiver 72 , or the external receiver 73 will result in turning of both the first threaded portion 41 and the second threaded portion 42 , and the first carriage 31 and the second carriage 32 will move simultaneously.
The central shaft 80 may be translated along the common axis relative to the first portion 41 and the second portion 42 of the threaded shaft 40 by applying a force F to the central shaft 80 , as noted in FIG. 10 . FIG. 11 illustrates the result of applying adequate force F to the central shaft 80 to overcome the biasing force of the detent 39 and thereby moving the central shaft 80 to the second position such that the detent 39 is located in the second indentation 82 rather than the first indentation 81 . As seen in FIG. 11 , the central shaft 80 is rotationally engaged with the first portion 41 of the threaded shaft 40 by engagement with first key 87 . However, the central shaft 80 is rotationally disengaged from the second portion 42 of the threaded shaft 40 at second key 88 . Consequently, turning of the first receiver 71 or the internal receiver 72 will result in turning the first threaded portion 41 and moving the first carriage 31 , but not in turning the second threaded portion 42 and moving the second carriage 32 . Turning of the external receiver 73 will result in turning the second threaded portion 42 and moving the second carriage 32 , but not in turning the first threaded portion 41 and moving the first carriage 31 . With this mechanism, it is possible to independently control either the first carriage 31 or the second carriage 32 from a single end of the transverse retractor 30 . This feature may be useful in expediently controlling the transverse retractor 30 without repositioning the device relative to a patient.
In the transverse retractor 30 shown in FIGS. 6-9 , a first transverse retractor appendage 51 is coupled with the first carriage 31 . The first retractor appendage 51 has a length and lateral sides 58 along its length. The transverse retractor 30 also includes a second transverse retractor appendage 52 coupled with the second carriage 32 . The second transverse retractor appendage 52 has a length and lateral sides 59 along its length. The coupling between each of the transverse retractor appendages 51 , 52 and respective carriages 31 , 32 of the illustrated embodiment is a rotatable coupling. In some embodiments, pressing of a button 91 rotationally releases each transverse retractor appendage 51 , 52 , relative to the respective carriages 31 , 32 allowing for relative rotation of the retractor appendages 51 , 52 . Releasing the button 91 may lock each transverse retractor appendage 51 , 52 , relative to the respective carriages 31 , 32 near a position of the transverse retractor appendage 51 , 52 at the time its respective button 91 is released. Instrument hooks 93 on each of the transverse retractor appendages 51 , 52 , are provided with some embodiments to facilitate attaching an instrument to apply rotational force to the transverse retractor appendages 51 , 52 . Rotating the transverse retractor appendages 51 , 52 may provide better access to a surgical site, including a larger subcutaneous working channel.
The first transverse retractor appendage 51 illustrated has a radius or curve about its longitudinal axis. The curve of the illustrated embodiment is a relatively small radius, but may be significantly enlarged in some designs of the invention. For example, the radius may be enlarged to produce a slightly curved appendage as illustrated in FIGS. 2 and 3 . In other embodiments, the transverse retractor appendage may be substantially flat or planar to form a substantially flat blade.
The second transverse retractor appendage 52 illustrated has a radius or curve about its longitudinal axis. The curve of the illustrated embodiment is a relatively small radius, but may be significantly enlarged in some designs of the invention. For example, the radius may be enlarged to produce a slightly curved appendage as illustrated in FIGS. 2 and 3 . In other embodiments, the transverse retractor appendage may be substantially flat or planar to form a substantially flat blade.
As is shown in combinations of FIGS. 1 , 2 , and 6 , the first retractor appendage 21 , the second retractor appendage 22 , the first transverse retractor appendage 51 , and the second transverse retractor appendage 52 are configured to be aligned substantially along their respective lengths and an access portal 99 to the surgical site is formed among the lateral sides 29 , 9 , 58 , 59 of the first retractor appendage 21 , the second retractor appendage 22 , the first transverse retractor appendage 51 , and the second transverse retractor appendage 52 .
Another embodiment of a surgical access instrument 101 is illustrated in FIG. 12 . The illustrated surgical access instrument 101 includes a flexarm retractor 110 couple with a transverse retractor 130 . The flexarm retractor 110 illustrated includes a base 111 . The base 111 of the embodiment shown is configured to couple with the transverse retractor 130 along a housing 133 of a frame 136 of the transverse retractor 130 . The coupling between the base 111 and the transverse retractor 130 may also be an interference fit or a fixed or pinned coupling in some embodiments. By way of example and without limitation, the coupling may be achieved by welding, may include an adhesive, may include a fastener such as a screw, pin, bolt, rivet, or the like, or may be accomplished through any other effective mechanism.
A rack 113 of the illustrated embodiment provides a connection between the base 111 and the first retractor appendage 121 through a bar 123 . The bar 123 extends away for the base 111 and terminates at the first retractor appendage 121 . The bar 123 shown is fixed to the base 111 . In other embodiments, the bar 123 may be slideably coupled to the base 111 so that the first retractor appendage 121 may be moved closer to or more distant from the surgical site relative to the base 111 by sliding the bar 123 relative to the base 111 .
The first retractor appendage 121 includes a length extending along its longitudinal axis and lateral sides 129 along its length. The first retractor appendage 121 illustrated has a radius or curve about its longitudinal axis. The curve of the illustrated embodiment has a relatively large radius, but may be significantly reduced in some designs of the invention. For example, the radius may be small to produce essentially a section of a tube. In other embodiments, the retractor appendage may be substantially flat or planar to form a substantially flat blade.
A flexible arm 115 is coupled to the base 111 at a proximal end 116 of the flexible arm 115 . A distal end 117 of the flexible arm 115 is movable relative to the base 111 . In the embodiment shown, multiple cannulated joints 118 interconnect with one another along a curvilinear path to form a continuous cannulated member. In some embodiments, the multiple cannulated joints 118 may interconnect with one another along a linear path. A tensile element (not shown) may be disposed through the cannula of the multiple cannulated joints 118 . The flexarm retractor 110 includes a control 127 in some embodiments attached to the tensile element to tighten and release the tensile element. The flexible arm 115 of the illustrated embodiment may have a free state and a locked state relative to the base 111 . The free state may exist when the tensile element is loosened and some or all of the cannulated joints 118 are rotatable relative to one another. Another example of a free state is where tension is applied to the tensile element to create some resistance between the cannulated joints 118 , but adequate lateral pressure to the flexible arm 115 will result in movement of the flexible arm 115 relative to the base 111 . A locked state may exist where significant tension is applied to the tensile element to prevent rotation or movement of the cannulated joints 118 relative to one another. In some embodiments, the second retractor appendage 122 may separately or in conjunction with the flexible arm 115 include a free state and a locked state as a result of tension applied to the tensile element or by other effective mechanisms.
In some embodiments, the control 127 also releases and locks the bar 123 relative to the base 111 . Therefore, by common activation of the control 127 , the first retractor appendage 121 , the flexible arm 115 , and the second retractor appendage 122 may all be switched between a free state and a locked state relative to the base 111 . In other embodiments, the bar 123 is independently movable relative to the base 111 and the tensile element is separately able to be tensioned.
The second retractor appendage 122 includes a length extending along its longitudinal axis and lateral sides 109 along its length. The second retractor appendage 122 illustrated has a radius or curve about its longitudinal axis. The curve of the illustrated embodiment has a relatively large radius, but may be significantly reduced in some designs of the invention. For example, the radius may be small to produce essentially a section of a tube. In other embodiments, the retractor appendage may be substantially flat or planar to form a substantially flat blade.
As is shown in FIG. 12 , the first retractor appendage 121 and the second retractor appendage 122 are aligned substantially along their respective lengths. An access portal 199 to a surgical site is formed between lateral sides 129 , 109 of the first retractor appendage 121 and the second retractor appendage 122 .
The transverse retractor 130 may be coupled to an operating table or other piece of surgical support structure through eyelets 195 . An assembly 135 includes a frame 136 , a threaded shaft 140 rotatably coupled with the frame 136 , a first carriage 131 coupled with the threaded shaft 140 that is configured to translate along the threaded shaft 140 when the threaded shaft is turned, and a second carriage 132 coupled with the threaded shaft 140 that is configured to translate along the threaded shaft 140 when the shaft is turned. The frame 136 illustrated includes a housing 133 , a center strut 134 , a first end cap 137 , and a second end cap 138 . The housing 133 of the illustrated embodiment is coupled to the center strut 134 . The first end cap 137 is coupled to the housing 133 , and the second end cap 138 is coupled to the housing 133 . Couplings between the components of the frame 136 may be by any effective means, such as but not limited to, welding, application of adhesives, clamping, snap fit components, or with any type of fastener.
The threaded shaft 140 shown couples with and rotates in the frame 136 . In the illustrated embodiment, the frame 136 supports the threaded shaft 140 with rotatable couplings in the first end cap 137 , the second end cap 138 , and at the center strut 134 . One or all of the rotatable couplings may include a bushing, a bearing, or a close tolerance fitting or some operable type. The rotatable couplings may include components made from materials other than the materials of the first end cap 137 , the second end cap 138 , and at the center strut 134 , or may be formed as a part of these components.
The threaded shaft 140 may be a unitary piece in some embodiments. In other embodiments, the threaded shaft 140 is composed of multiple components and interacts to provide additional functionality to the transverse retractor 130 and surgical access instrument 101 as, for example, detailed with regard to the transverse retractor 30 above. A first portion of the threaded shaft 140 may have right-hand threads that interact with a first carriage 131 , and a second portion of the threaded shaft 140 may have left-hand threads that interact with a second carriage 132 . With such an arrangement, rotation of the threaded shaft 140 in a first rotational direction will result in the first carriage 131 and the second carriage 132 moving together, or toward one another, simultaneously. Rotation of the threaded shaft 140 in a second rotational direction opposite from the first rotational direction will result in the first carriage 131 and the second carriage 132 moving apart simultaneously.
In embodiments of the transverse retractor 130 , various transverse retractor appendages may be coupled to one or both of the first carriage 131 and the second carriage 132 . Transverse retractor appendages 51 , 52 detailed above are non-limiting examples of devices that may be used in conjunction with the first carriage 131 and the second carriage 132 .
Embodiments of the invention include a portal means for accessing a surgical site. The portal or access means may include a first retractor means for retracting tissue in a first direction. Additionally, the portal means may include a flexarm retractor means for retracting tissue in a second direction substantially transverse to the first direction. The flexarm retractor may further be capable of assuming a flexible state and a rigid state along its length in response to the actuation of a single control.
All or a portion of the surgical access instruments of embodiments of the disclosed invention may be made of any biocompatible material. For example and without limitation, materials of the surgical access instruments may include non-reinforced polymers, carbon-reinforced polymer composites, PEEK and PEEK composites, low density polyethylene, shape-memory alloys, titanium, titanium alloys, cobalt chrome alloys, stainless steel, ceramics and combinations thereof. Material of the surgical access instruments may be radiopaque or may be radiolucent. If radiolucent, the instruments may include markers placed in certain components of the instruments to provide for guidance of the instruments under radiographic imaging.
Another embodiment of the invention is a method of creating an access portal to a surgical site. The method includes introducing a first retractor into the surgical site such that the retractor is in a position to separate tissues along a first axis. The first retractor may include mechanisms for independently moving two retractor appendages or blades along the first axis. The method also includes introducing a flexarm retractor into the surgical site such that the flexarm retractor is in a position to separate tissues along a second axis that is substantially transverse to the first axis. The flexarm retractor of some embodiments includes a base, a first retractor appendage coupled to the base, a flexible arm coupled to the base at a proximal end of the flexible arm, and a second retractor appendage coupled to the flexible arm at a distal end of the flexible arm. The method further includes coupling the flexarm retractor with the first retractor, separating the first retractor appendage from the second retractor appendage to create an access portal to the surgical site, and actuating a control on the flexarm retractor to stiffen the flexible arm to fix the second retractor appendage in a desired location. In some embodiments, actuating the control on the flexarm retractor to stiffen the flexible arm also locks the first retractor appendage relative to the base. Embodiments of the method may further include operating the first retractor to separate tissues along the first axis.
Still another embodiment of the invention is a method of creating an access portal to a surgical site. The method includes introducing a retractor with two appendages into the surgical site such that the retractor is in a position to separate tissues along an axis. The retractor may include mechanisms for switching from a first state where one rotational control moves both appendages simultaneously together or apart along the axis to a second state where the one rotational control moves only one of the appendages along the axis. In some embodiments, the mechanism for switching between the first and second states requires application of a force to a portion of the retractor along the axis. In some embodiments, application of another force in a direction substantially opposite to the direction of the first force results in a return to the first state where one rotational control moves both appendages simultaneously together or apart along the axis.
Various method embodiments of the invention are described herein with reference to particular devices. However, in some circumstances, each disclosed method embodiment may be applicable to each of the devices, or to some other device operable as disclosed with regard to the various method embodiments.
Terms such as proximal, distal, near, lower, upper, lateral, and the like have been used herein to note relative positions. However, such terms are not limited to specific coordinate orientations, but are used to describe relative positions referencing particular embodiments. Such terms are not generally limiting to the scope of the claims made herein.
While embodiments of the invention have been illustrated and described in detail in the disclosure, the disclosure is to be considered as illustrative and not restrictive in character. All changes and modifications that come within the spirit of the invention are to be considered within the scope of the disclosure.
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Embodiments of the invention include instruments and methods for providing surgical access to a surgical site. Some embodiments include a flexible arm that adjustably holds a retractor blade to enable access to the surgical site.
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This application is a continuation of application Ser. No. 07/188,237, filed Apr. 29, 1988, now U.S. Pat. No. 4,935,237, which is a continuing application under 35 U.S.C. 120/121 of U.S. Ser. No. 07/170,970 filed Mar. 21, 1988 now abandoned and of U.S. Ser. No. 07/068,448 filed June 30, 1987, now abandoned and the contents thereof are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed generally to processes for improving human tissue plasminogen activator (t-PA) protein and, in particular, to processes for improving the pharmacokinetic characteristics of t-PA.
2. Description of the Related Art
Human tissue plasminogen activator, t-PA, is an extremely important new biological pharmaceutical agent shown to have great promise in the treatment of vascular disease due to its high specificity and potent ability to dissolve blood clots in vivo. Accordingly, t-PA has been hailed by medical science as one of the most impressive new agents of recent history for the treatment of vascular disease, and in particular, heart disease. For these and other reasons, t-PA will likely revolutionize the clinical management of serious vascular disease.
Human t-PA protein, as well as the underlying gene sequences which code for it, has been the subject of numerous scientific disclosures over the previous few years. For example, the structure of t-PA protein, as well as its isolation from natural sources, has been described by Rijken et al., (1981), J. Biol. Chem., 256:7035. Moreover, a patent and various patent applications have been published detailing the isolation of natural t-PA from both natural and recombinant sources (see, e.g., UK Patent 2,119,804; European Patent Application Publication No. 041766; and European Patent Application Publication No. 093619). Based on such disclosures, it is now clear that natural t-PA, whether naturally isolated or a recombinant species thereof, typically includes 5 domains which have been defined with reference to homologous or similar structures identified in various other proteins. These domains have been designated as the finger (F), growth factor (G), kringle 1 (K1), kringle 2 (K2), and protease (P) regions and are situated contiguously in the N-terminus to C-terminus direction of the protein backbone structure.
In spite of the profound advantages identified with natural human t-PA as a clot dissolving pharmaceutical agent, certain drawbacks are associated with its use under various circumstances. For example, natural t-PA has an extremely short plasma half-life, typically about 6 minutes or so, when administered to patients in therapeutically effective amounts. Moreover, in terms of clearance rate, another important pharmacokinetic indicator, natural t-PA typically exhibits an extremely high clearance rate of about 7 to 8.5 ml/min/kg. Short half-lives and high clearance rates are desirable under certain circumstances, for example, when acute aggressive therapy of a life threatening disease such as myocardial infarction or pulmonary embolism is undertaken. In this high risk situation, patients may be treated who have significant or unrecognized potential for uncontrolled bleeding. If such bleeding would occur, drug administration could be stopped and the causative t-PA levels would be rapidly depleted by high clearance rates.
However, in other circumstances, for example, in the treatment of myocardial infarction following reperfusion, the desired therapeutic regimen is less aggressive and of extended duration (4 to 12 hours). A long half-life form of t-PA can be perceived as a more desirable, efficient and convenient treatment in patients who are not in life-threatening situations. Moreover, a longer half-life t-PA would be desirable as an agent for bolus administration, for example, by ambulance technicians, where infusion capability is generally not available, it would be much more desirable to employ t-PA-like agents having greater half-lives and/or lower clearance rates.
Accordingly, there is currently a need to identify improved processes and associated embodiments for preparing t-PA variants having improved pharmacokinetic parameters yet which retain high clot lysis activity in vivo. Such would provide medical science important new alternatives to the treatment of cardiovascular disease and in treatment of numerous other medical conditions which arise out of thromboembolic occlusion of blood vessels.
SUMMARY OF THE INVENTION
Recognizing these and other disadvantages in the art, it is a general object of the present invention to provide improved processes for the treatment of vascular disease, in particular, in the prevention of rethrombosis of coronary arteries, in affected patients.
It is a particular object of the present invention to provide processes particularly adapted for the treatment of patients in need of clot dissolving agents that have a longer half-life, and/or decreased clearance rate, relative to currently available clot dissolving agents.
It is a more particular object of the present invention to provide processes for the treatment of conditions which admit the use of clot dissolving agents having longer half-lives and/or decreased clearance rates relative to natural t-PA, for example, conditions such as deep vein thrombosis or peripheral arterial thrombosis (peripheral vascular disease).
Accordingly, in a general and overall sense, the present invention embodies a realization by the present inventors that variants of human t-PA protein may be produced which exhibit longer half-lives and/or reduced clearance rates relative to natural t-PA, yet which retain high clot lysis activity in vivo. As used herein, the term "variant human t-PA protein" refers to protein structures which include basic structural features of natural t-PA, for example, corresponding in general to amino acid sequences found in natural t-PA or to biologically functional equivalents of such sequences of amino acids, yet which structures have been altered in one or more ways to produce a variant protein having a statistically increased half-life and/or clearance rate relative to natural t-PA. As used herein, the term "natural t-PA" is meant to include t-PA, for example, as described in EPO application publications 041766 and 093619, whether obtained from natural or recombinant sources.
The present invention is thus directed generally to improved methods for the treatment of vascular disease in a patient in need of a "half-life enhanced" or "clearance rate reduced" t-PA agent. Such processes include generally preparing a variant t-PA protein which exhibits a greater plasma half-life, for example, at least about 2 times longer than that exhibited by natural t-PA, or which exhibits a reduced clearance rate, for example, about 1/2 or less, than the clearance rate exhibited by natural t-PA proteins. The variant t-PA protein is formulated with various pharmaceutically acceptable carriers or excipients, in amounts adequate to provide a therapeutic benefit to a patient in a convenient dosage, followed by administering appropriate amounts to a patient in need in accordance with the particular circumstances.
It will be appreciated by those of skill in the art that by "half-life" or "plasma half-life" is meant the time for a drug concentration in the plasma to be reduced by one-half, typically measured after administration of a selected dose. Accordingly, half-life measures the time of elimination of one-half the drug concentration in the plasma. In contrast, by the term "clearance rate" is meant the rate of drug elimination divided by the concentration of the drug in the particular fluid, generally plasma. By "plasma" herein is meant either plasma or serum. The concept of clearance is extremely useful in clinical pharmacokinetics because clearance of a given drug is usually constant over most clinically encountered drug concentrations, and may typically be fit to first order rate kinetics. Clearance rate may at times be more particularly defined as the dose given divided by AUC, wherein AUC is defined as the area under the plasma concentration time curve. Accordingly, by an "increased", "enhanced" or "longer" half-life is meant a half-life that is statistically longer. Moveover, by "decreased" or "reduced" clearance rate is meant one that is statistically reduced.
In that the pharmacokinetics of natural t-PA appear to be biphasic or multiphasic, such pharmacokinetics are typically fit to bi- (or multi-) exponential equations. Accordingly, it should be recognized that the half-life numbers reflected herein are "nominal" half-lives, thus reflecting the dominant half-life of natural t-PA is about 2.2 minutes for t1/2a and about 30 minutes for t1/2b. However, where Co=100, then the t1/2a component is generally about 95% and t1/2b component about 5%. Accordingly, the alpha phase is dominant and reflects the nominal half-life.
Surprisingly, it has been discovered that the key to the preparation of variant t-PA proteins which effectively retain the high in vivo clot lysis activity of natural t-PA, is the removal of all or a portion of the finger region or all or a portion of the growth factor region, or all or a portion of the Kringle 1 region, typically associated with natural t-PA. As used herein, the term "finger region" refers generally to the amino-terminus region of natural t-PA protein, which exhibits a "finger-like" structure due to the presumed location of disulfide bonds between cysteine residues 6 and 36, and 34 and 43. The finger region may be alternatively defined in terms of the underlying gene structure as the individual finger-coding exon region, for example, as characterized by Type 1 homologies with fibronectin and as an independent exon region. Accordingly in certain preferred embodiments the finger region includes amino acids corresponding to amino acids about 1 (SER) through about 44 (HIS) of natural t-PA.
The growth factor region (G) has been variously defined as stretching from about amino acid 45 upwards of amino acid 91 (based upon its homology with EGF). Kringle one (K1) has been defined as stretching from about amino acid 92 to about 173 and kringle two (K2) has been defined as stretching from about amino acid 180 to about amino acid 261. The so-called serine protease domain (P) to the C-terminal end of the molecule. These domains are situated contiguously generally of one another, or are separated by short "linker" regions, and account for the entire amino acid sequence of from 1 to 527 amino acids in its putative mature form.
Each domain has been described variously as contributing certain specific activity: that is, the finger domain has been variously described as containing a sequence essential or at least of major importance for high binding affinity to fibrin. (This activity is thought important for the high specificity human tissue plasminogen activator displays with respect to clot lysis at the locus of a fibrin rich thrombus.) The growth factor-like region likewise has been associated with cell surface binding activity, at least with respect to urokinase. The Kringle 2 region has also been strongly associated with fibrin binding and with the ability of fibrin to stimulate the activity of t-PA. The serine protease domain seems to enjoy unanimous agreement of being the workhorse domain of the molecule in respect of plasminogen activating activity.
The invention therefore contemplates a process for increasing the plasma half-life of t-PA in a manner which relates to the amount or portion of finger; growth factor or Kringle 1 domain removed. Thus, the greater the degree of such domain functional alteration reflected in the t-PA variant, the greater the increase in half-life exhibited by the variant. However, it has been found that even removal of virtually the entire finger, growth factor or Kringle 1 region results in little reduction in clot lysis activity in vivo. Accordingly, pharmaceutical preparations may be readily prepared with variant t-PA proteins of the present invention which retain clot lysis activity in vivo, employing variants which include one or more of functional finger, growth factor, kringle 1, kringle 2 and/or protease domain, yet having at least a portion of the finger, growth factor or Kringle 1 region removed or altered.
In certain preferred embodiments, the t-PA variants so produced and clinically employed have essentially the entire finger domain removed, characterized in particular by the removal of amino acids corresponding to amino acids 1 through 44 of natural t-PA (designated herein as "des (1-44) t-PA").
In other preferred embodiments hereof, amino acids 44 to 84, substantially the entire growth factor region, are deleted or amino acids 92 to 179, substantially the entire Kringle 1 region, are deleted.
t-PA variants prepared in accordance with the present invention exhibit plasma half-lives generally at least 2 times greater than that of natural t-PA and, in certain embodiments, exhibit half-lives between about 5 and about 20 times the plasma half-life exhibited by natural t-PA. In that the plasma half-life of natural t-PA is about 6 minutes in man, preferred variant t-PA preparations of the present invention typically exhibit half-lives of at least 12 to 20 minutes and, in the case of des (1-44) t-PA, up to an hour or more.
It will be appreciated that the "nominal" half-life of natural t-PA in rabbits, monkeys and man, are about 2, 3.5 and 6 minutes, respectively. This ratio is typically relatively constant. Thus, a half-life observed in, for example, rabbit would correspond to a somewhat greater half-life in man.
In other embodiments, the improved pharmacokinetics of variant t-PA structures is defined in terms of decreased clearance rate of the agent. In such embodiments, variant t-PA proteins are provided which exhibit clearance rates of 1/2 to 1/5 or less the clearance rate of natural t-PA, preferably a clearance rate of between about 1/15 and about 1/25 the clearance rate of natural t-PA. In most accepted test systems, as well as in man, natural t-PA will generally exhibit a clearance rate of on the order of 7 to 8.5 ml/min/kg. However, t-PA variants employed in the practice of the present invention will typically exhibit a clearance rate of less than about 2 ml/min/kg, with the preferred des (1-44) t-PA variant exhibiting a clearance rate of less than about 0.5 ml/min/kg.
In order to avoid the possibility of untoward effects and unknown toxicities of variant t-PA protein preparations, it is preferred although not required, that the variant protein so produced be free of synthetic derivatives, such as, for example, derivatives wherein alkyl, alkylamine or methylated benzylamines or other blocking groups are included on the protein structure.
However, other modifications have previously been found to provide improved t-PA, and such modified t-PA's may also be employed in processes of the present invention. For example, novel t-PA mutant having certain amino acid substitutions in the region of amino acids 270 to about 279, and more particularly, positions 275, 276 and 277 of human t-PA have been described in U.S. Ser. No. 07/071,506, filed July 9, 1987, and its parent application Ser. Nos. 06/846,697, filed Apr. 1, 1986 and Ser. No. 06/725,468, filed Apr. 22, 1985 (corresponding to European Patent Application Publication No. 199,574, published Oct. 29, 1986, all of which applications are herein incorporated by reference). These mutants, characterized preferentially as t-PA mutants having an amino acid other than arginine at position 275, or lysine at position 277, are referred to herein as protease-resistant one-chain t-PA variants in that, unlike natural t-PA which can exist in both a one-chain or two-chain form, they are resistant to protease cleavage at positions 275 and/or 277 and are therefore not converted metabolically in vivo into a two-chain form. Such resistant "one-chain" variants are similarly improved by processes of the present invention and are included within the scope hereof. Examples of such enzymatically resistant (at amino acid positions 275 and/or 277) hereof include these such-like variants in combination with a missing (at least a portion of) finger, growth factor or kringle 1 region, for example des 1-44 Glu 275 t-PA and des 1-44 Glu275Iso277 t-PA.
Although it is believed that variant t-PA proteins may be obtained, for example, by enzymatic cleavage of natural t-PA followed by enzymatic addition of selected amino acids or even through totally synthetic means, in preferred embodiments, t-PA variants are obtained through the practice of recombinant DNA technology and cell culture techniques. Starting recombinant vectors, and the recombinant techniques for forming, culturing and expressing appropriate t-PA variants through the use of such vectors, are known generally in the art or have been set forth in detail herein.
In general, preferred recombinant processes for preparing appropriate variant t-PA proteins includes preparing a recombinant vector which encodes the variant, for example, encoding amino acids corresponding to amino acids 45 through 527, excluding amino acids 1-44 of natural t-PA in the case of des (1-44) t-PA, aand similarly excluding the appropriate amino acids in the case of des growth factor and des kringle 1 t-PA. It will be appreciated that through the use of recombinant DNA technology to prepare variant t-PA proteins, variants are produced wherein the size and sequence of the finger, growth factor or kringle 1 region retained may be controlled with high specificity. Moreover, large quantities of variant protein may be produced and further purified by conventional means to provide pharmaceutically acceptable preparations. The product produced by genetically engineered microorganisms or cell culture systems provides an opportunity to produce human tissue plasminogen activator in a much more efficient manner than has been possible, enabling hitherto elusive commercial exploitation. In addition, depending upon the host cell, the human tissue plasminogen activator hereof may contain associated glycosylation to a greater or lesser extent compared with native material. In any event, the t-PA will be free of contaminants, such as contaminating proteins and other adventitious agents, for example, viral based entities, normally associated with it in a non-recombinant cellular environment or in pooled serum derived preparations.
The compounds of the present invention can be formulated according to known methods to prepare pharmaceutically useful compositions, whereby the modified human t-PA product of the present invention is combined in admixture with a pharmaceutically acceptable carrier vehicle. Suitable carrier vehicles and their formulation, inclusive of other human proteins, e.g., human serum albumin, are described, for example in Remington's Pharmaceutical Sciences 16th ed., 1980, Mack Publishing Co., edited by Oslo et al., which is hereby incorporated by reference. Such compositions will typically contain an effective amount of the variant t-PA, for example, from about 0.5 to about 5 mg/ml., together with a suitable amount of carrier vehicle in order to prepare pharmaceutically acceptable compositions suitable for effective administration to the host. The t-PA composition can be administered parenterally, or by other methods that ensure its delivery to the bloodstream in an effective form and amount.
Compositions particularly well suited for the clinical administration of variant t-PA products employed in the practice of the present invention include, for example, sterile aqueous solutions, or sterile hydratable powders such as lyophilized protein. It is generally desirable to further include in the formulation an appropriate amount of a pharmaceutically acceptable salt, generally in an amount sufficient to render the formulation isotonic. A pH regulator such as arginine base, and phosphoric acid, are also typically included in sufficient quantities to maintain an appropriate pH, generally from 5.5 to 7.5. Moreover, to improve shelf-life or stability of aqueous formulations, it may also be desirable to further include agents such as glycerol. In this manner, variant t-PA formulations are rendered appropriate for parenteral administration, and in particular, intravenous administration.
Dosages and desired drug concentrations, of pharmaceutical compositions of the present invention may vary depending on the particular use envisioned. For example, in the treatment of deep vein thrombosis or peripheral vascular disease, "bolus" doses on the order of about 0.05 to about 0.3 mg/kg, will typically be preferred with subsequent administrations, on the order of about 0.1 to about 0.2 mg/kg, being given to maintain an approximately constant blood level, preferably on the order of about 3 μ2 g/ml. However, for use in connection with emergency medical care facilities where infusion capability is generally not available and due to the generally critical nature of the underlying disease (e.g., embolism, infarct), it will generally be desirable to provide somewhat larger initial doses, such as an intravenous bolus on the order of 0.3 mg/kg.
For example, the human tissue-type plasminogen activator hereof may be parenterally administered to subjects suffering from cardiovascular diseases or conditions. Dosage or dose rate may parallel that currently in use in clinical investigations of other cardiovascular, thrombolytic agents, e.g. about 1-2 mg/kg body weight as an intravenous or intra-arterial dose over 1.5-12 hours in patients suffering from myocardial infarction, pulmonary embolism, etc.
As one example of an appropriate dosage form, a vial containing 50 mg human tissue-type plasminogen activator, arginine, phosphoric acid and polysorbate 80 may be reconstituted with 50 ml sterile water for injections and mixed with a suitable volume of 0.9 percent Sodium Chloride Injection.
The extended half-life of human tissue-type plasminogen activator hereof may be suitable for rapid i.v. injection. This would eliminate the need for complex administration procedures and may increase the opportunity for the use of t-PA in settings with limited medical equipment such as in emergency vehicles staffed with paramedic personnel. An extended half-life of human tissue-type plasminogen activator may also allow lower, safer initial doses and could maintain thrombolytically effective plasma levels for up to 45 minutes or longer. A longer half-life of human tissue-type plasminogen activator may also be useful for low dose extended therapy which may be necessary to avoid reocclusion following successful acute thrombolysis or for extended thrombolysis which may be necessary in cases of peripheral vascular occlusion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1C show the nucleic acid sequence, and corresponding amino acid sequence, of full-length human t-PA (amino acids 1-527), including the putative presequence region (amino acids -35 to -1), as well as 5' and 3' - flanking sequences.
FIG. 2 shows schematically the steps taken in generating a des (1-44) t-PA variant-coding mutant plasmid.
FIG. 3 shows a polyacrylamide gel comparing the migration of natural t-PA to the des (1-44) variant t-PA, both in the presence and absence of reducing agents.
FIG. 4 compares the fibrin stimulation of des (1-44) t-PA and natural t-PA in vitro using the plasmin specific substrate S-2251.
FIG. 5 compares the fibrin-binding activity of natural t-PA (intact fibrin, □, and plasmin-degraded fibrin, ) to des (1-44) t-PA (intact fibrin, 0, and plasmin degraded, ).
FIG. 6 compares the in vivo thrombolytic activity of des (1-44) t-PA (N44) to natural t-PA (RIK) in rabbits (n-6, 5+S.D., respectively).
FIG. 7 compares the lysis rate of natural t-PA () to the des (1-44) t-PA variant ( ), at a dose of 0.3 and 0.064 mg/kg, respectively, given as a 10% bolus, followed by infusion of the remainder over 90 minutes.
FIG. 8 compares the time course of the plasma concentration resulting from an administration of 0.3 natural or 0.064 mg/kg N44 variant, given as a 10% mg/kg bolus with the remaining infused over a 90 min. time course.
FIG. 9 compares the pharmacokinetics of N44 to natural t-PA (rt-PA), using non-radioactive rt-PA as the carrier.
FIG. 10 displays the pharmacokinetics of N44, using N44 as the carrier.
FIG. 11 is a schematic representation of how plasmid p1154 can be prepared and demonstrates also a partial restriction mapping thereof.
FIG. 12 shows the sequence of the des 1-44 Glu 275 t-PA mutant encoded by plasmid p1154.
FIG. 13 shows the pharmacokinetic profiles, in rabbits, of the various domain deletion mutants: growth factor deletion, des 44-84 ("d-GF"); Kringle 1 deletion, des 92-179 ("d-K1"); Kringle 2 deletion, des 174-261 ("d-K2"); and native t-PA ("rt-PA") as a control.
FIG. 14 shows the fibrin binding characteristics of the various domain deletion mutants (See FIG. 13) including finger deletions des 1-44, expressed as percent bound versus fibrin(ogen) concentration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
I. Introduction
In man and other animals, tissue-type plasminogen activator (t-PA) plays an essential role in the dissolution of fibrin clots (see, e.g., Verstraete and Collen (1986) Blood, 67:1425). t-PA is a serine protease that initiates fibrinolysis by converting plasminogen to plasmin. t-PA is composed of several domains which share sequence homology with other proteins and it has been postulated that each domain contributes a specific function to this multifunctional protein (see, e.g., Pennica et al., (1983), Nature, 301:214; Banyai et al. (1983), FEBS Lett., 163:37). Only the function of the protease domain (residues 276-527) has been unambiguously defined. This finding was first based on the observed sequence homology with other known serine proteases. More recently, limited reduction of the two-chain form of t-PA has allowed the direct isolation and functional characterization of the protease region (Rijken and Groeneveld (1986), J. Biol. Chem., 261:3098; Dodd et al. (1986), Thrombos. Haemostas., 55:94).
However, the precise function(s) of the finger domain (e.g., see FIGS. 1 A-C; residues 1-44 which are homologous with the type 1 finger regions of fibronectin), the growth factor domain (residues 45-89, which are homologous to epidermal growth factor, and the growth factor regions in urokinase, factor IX, factor X and protein C) and the two kringle domains (residues 92-173, and 180-261, which are homologous to the kringle regions in plasminogen, prothrombin, urokinase, and factor XII) are presently unknown. Banyai, et al., supra, employed sequence homology with the finger domains responsible for the fibrin affinity of fibronectin and limited proteolytic studies on t-PA to suggest that the amino-terminal finger domain is responsible for t-PA's fibrin affinity. Alternatively, Ichinoise, et al. (1986), J. Clin. Invest., 78:103, have used sequence homology with the kringle domains responsible for the fibrin affinity of plasminogen and limited proteolysis to suggest that the second kringle domain of t-PA is responsible for the interaction with fibrin.
Site-specific mutagenesis is a technique which allows for the selective deletion of desired portions of a particular protein through selective deletion of corresponding underlying gene sequences. When combined with functional characterization of the resulting mutant, such techniques may allow elucidation of the function or functions of each domain. For example, Bang, et al. (1985), Clin. Res., 33:878A, have presented preliminary work using this approach, which indicates that the finger and growth factor domains are sufficient for fibrin binding and maximal stimulation of the activity by fibrin. In contrast, van Zonneveld, et al. (1986), Proc. Natl. Acad. Sci. USA, 83:4670, have shown by using a transient expression system and unpurified supernatants that the second kringle domain and to a lesser extent the finger and growth factor domains are responsible for fibrin binding. However, Kagitani, et al. (1985), FEBS Lett., 189:145, isolated a naturally occurring t-PA cDNA coding for residues 50-527 from Detroit 562 cells and characterized the protein after expression in E. coli. In contrast to other researchers, they found that this mutant which was missing the finger domain and a portion of the growth factor domain did bind to fibrin.
Verheijen et al., EMBO 5, 3525 (1986) have prepared a series of variants of t-PA lacking one or more domains. They found that in the absence of plasminogen at low concentrations of fibrin, removal of the finger domain significantly decreased fibrin binding; however, at high concentrations of fibrin, the presence of the second kringle domain seems sufficient to ensure significant binding. In the presence of plasminogen, the kringle two domain is also important at low fibrin concentrations. They also concluded that only the kringle two domain is involved in stimulation of activity by fibrin.
Accordingly, there has been much confusion and uncertainty surrounding the functional significance of the various structural domains, and in particular, the role played by the N-terminal finger domain of natural t-PA. However, based upon the present invention, it can now be unequivocally disclosed that among certain other possible pharmacologic attributes of the finger, growth factor or kringle 1 domain, it is clear that the presence of these domains in t-PA proteins directly correlates with the short half-life of natural t-PA. In particular, it can now be disclosed that removal of the finger, growth factor or kringle 1 region, for example, as exemplified by removal of the first 44 amino acids of natural t-PA in the case of removal of the finger region, results in a variant t-PA proteins that exhibit surprising and unexpected pharmacokinetic properties in light of what has previously been known regarding natural t-PA and its associated intramolecular structures.
II. Preparation of t-PA Variants
As noted above, recombinant techniques are preferred for the preparation of t-PA variants employed in the processes of the present invention. In particular, recombinant DNA technology is employed for the preparation of these human t-PA deletion mutants, variously modified by resultant single or multiple amino acid substitutions, deletions, additions and replacements, for example, by means of site directed deletion mutagenesis. Included would be the preparation of t-PA deletion variants having all or part of the finger region deleted, yet retaining the kringle region(s) and serine protease region characteristic generally of human tissue plasminogen activator described previously (e.g., see UK Patent 2,119,804, incorporated herein by reference), but otherwise modified by removal or alteration of the finger region.
It will be appreciated by those of skill in the art that, in the context of the specific deletions employed in the practice of the instant processes, as used herein, "human tissue plasminogen activator", "human t-PA" or "natural t-PA" denotes human extrinsic (tissue-type) plasminogen activator, produced by microbial or cell cultures systems, in bioactive forms comprising a protease portion and corresponding to those tissue plasminogen activators otherwise native to human tissue. The human tissue plasminogen activator protein produced herein has been defined by means of determined DNA gene and deductive amino acid sequencing (see FIGS. 1 A-C). It will be understood that natural allelic variations exist and occur from individual to individual. These variations may be demonstrated by amino acid differences in the overall sequence or by deletions, substitutions, insertions, inversions or additions of amino acids in said sequence. In addition, the location of and degree of glycosylation depend on the nature of the host cellular environment.
All such allelic variations and modifications resulting in derivatives of human tissue plasminogen activator characterized as biological functional equivalents of t-PA are included within the scope of this invention, as well as other related human extrinsic (tissue-type) plasminogen activators, similar physically and biologically, so long as the essential, characteristic human tissue plasminogen activator activity remains unaffected in kind. Moreover, it is known that certain alterations may be made in the amino acid sequence without altering the underlying biological function of the protein. For example, it is known that amino acids may be exchanged with various other amino acids based on a correlation of the hydropathic index of the two exchanged amino acids.
As with t-PA, variant t-PA of the present invention is typically prepared (1) having methionine as its first amino acid (present by virtue of the ATG start signal codon insertion in front of the structural gene) or (2) where the methionine is intra-or extracellularly cleaved, having its normally first amino acid, or (3) together with either its signal polypeptide or a conjugated protein other than the conventional signal polypeptide, the signal polypeptide or conjugate being specifically cleavable in an intra-or extracellular environment, or (4) by direct expression in mature form without the necessity of cleaving away any extraneous, superfluous polypeptide. The latter is particularly important where a given host may not, or not efficiently, remove a signal peptide where the expression vehicle is designed to express the tissue plasminogen activator together with its signal peptide. In any event, the thus produced human variant t-PA, in its various forms, is recovered and purified to a level fitting it for use in the treatment of the various vascular conditions or diseases.
Furthermore, t-PA has forms which include both the single chain (non-protease resistant 1-chain) protein and the 2-chain protein. The latter is proteolytically derived from the nonresistant 1-chain compound. It is theorized that the 2-chain occurs at the locus of the conversion of plasminogen to plasmin. The present invention provides for the administration of variant 1-chain protein, whether protease resistant or not, or for the administration of 2-chain protein, which has also been shown to be active. The 2-chain protein can be prepared by in vitro proteolytic conversion after the nonresistant 1-chain material is produced. A so-called "kringle" area is positioned upstream from the serine protease portion and is believed to play an important function in binding the tissue plasminogen activator hereof to a fibrin matrix, hence, the observed specific activity of the present tissue plasminogen activator toward tangible, extant thrombi. The tissue plasminogen activator hereof is produced containing the enzymatically active portion corresponding to native material and the term human tissue plasminogen activator defines products comprising such portion alone or together with additional amino acid sequences up to the full length molecule.
"Essentially pure form" when used to describe the state of the variant human t-PA produced by the invention means free of protein or other materials normally associated with human t-PA when produced by non-recombinant cells, i.e. in its "native" environment.
"DHFR protein" refers to a protein which is capable of the activity associated with dihydrofolate reductase (DHFR) and which, therefore, is required to be produced by cells which are capable of survival on medium deficient in hypoxanthine, glycine, and thymidine (-HGT medium). In general, cells lacking DHFR protein are incapable of growing on this medium, cells which contain DHFR protein are successful in doing so. For this reason, inclusion of DHFR-coding sequences in recombinant vectors of the present invention allows a means of selecting successfully transformed hosts.
"Cells sensitive to MTX" refers to cells which are incapable of growing on media which contain the DHFR inhibitor methotrexate (MTX). Thus, "cells sensitive to MTX" are cells which, unless genetically altered or otherwise supplemented, will fail to grow under ambient and medium conditions suitable for the cell type when the MTX concentration is 0.2 μg/ml or more. Some cells, such as bacteria, fail to exhibit MTX sensitivity due to their failure to permit MTX inside their cell boundaries, even though they contain DHFR which would otherwise be sensitive to this drug. Thus, in general, cells which contain DHFR will be sensitive to methotrexate only if they are permeable to, or capable of uptake of, MTX.
"Wild type DHFR" refers to dihydrofolate reductase as is ordinarily found in the particular organism in question. Wild type DHFR is generally sensitive in vitro to low concentrations of methotrexate.
"Expression vector" includes vectors which are capable of expressing DNA sequences contained therein, where such sequences are operably linked to other sequences capable of effecting their expression. It is implied, although not always explicitly stated, that these expression vectors must be replicable in the host organisms either as episomes or as an integral part of the chromosomal DNA. Clearly a lack of replicability would render them effectively inoperable. In sum, "expression vector" is given a functional definition, and any DNA sequence which is capable of effecting expression of a specified DNA code disposed therein is included in this term as it is applied to the specified sequence. In general, expression vectors of utility in recombinant DNA techniques are often in the form of "plasmids" which refer to circular double stranded DNA loops which, in their vector form are not bound to the chromosome. In the present specification, "plasmid" and "vector" are used interchangeably as the plasmid is the most commonly used form of vector. However, the invention is intended to include such other forms of expression vectors which serve equivalent functions and which become known in the art subsequently hereto.
"Recombinant host cells" refers to cells which have been transformed with vectors constructed using recombinant DNA techniques. As defined herein, variant t-PA is produced in the amounts achieved by virtue of this transformation, rather than in such lesser amounts, or, more commonly, in such less than detectable amounts, as might be produced by the untransformed host. t-PA produced by such cells can be referred to as "recombinant t-PA".
As used herein, a "biological functional equivalent" of t-PA or variant t-PA, refers to natural or variant t-PA wherein the natural sequence (or corresponding variant sequence), for example, as illustrated in FIGS. 1A-1C, is replaced by one having a similar biological function. For example, it has been found by Kyte et al. (1982), J. Mol. Biol., 157:105, that certain amino acids may be substituted for other amino acids having a similar hydro-pathic index or score, and still retain a similar biologic activity. As displayed in the table below, amino acids are assigned a hydropathic index on the basis of their hydrophobicity and charge characteristics. It is believed that the relative hydropathic character of the amino acid determines the secondary structure of the resultant protein, which in turn defines the interaction of the protein with its receptor. In the case of t-PA, it is believed that biological functional equivalents of t-PA may be obtained by substitution of amino acids having similar hydropathic values. As used herein, a biological functional equivalent of t-PA or variant t-PA in terms of biological activity. Thus, for example, isoleucine, which has a hydropathic index of +4.5, can be substituted for valine (+4.2) or leucine (+3.8), and still obtain a protein having like biological activity. Alternatively, at the other end of the scale, lysine (-3.9) can be substituted for arginine (+4.5), and so on. In general, it is believed that amino acids can be successfully substituted where such amino acid has a hydropathic score of within about +/-1 hydropathic index unit of the replaced amino acid.
______________________________________Amino Acid Hydropathic Index______________________________________Isoleucine 4.5Valine 4.2Leucine 3.8Phenylalanine 2.8Cysteine/cystine 2.5Methionine 1.9Alanine 1.8Glycine -0.4Threonine -0.7Tryptophan -0.9Serine -0.8Tyrosine -1.3Proline -1.6Histidine -3.2Glutamic Acid -3.5Glutamine -3.5Aspartic Acid -3.5Asparagine -3.5Lysine -3.9Arginine -4.5______________________________________
a. Site-Specific Deletion Mutagenesis
As discussed above, TPA variants hereof are preferably produced by means of specific deletion mutations. Deletion mutants useful in the practice of the invention are formed most readily through the use of specific oligonucleotide sequences which encode the DNA sequence of the desired deletion junction, as well as a sufficient number of adjacent nucleotides, to provide a primer sequence of sufficient size and sequence complexity to form a stable duplex on both sides of the deletion junction being traversed. Typically, a primer of at least 27 nucleotides in length is preferred, with about 10 nucleotides on the 5' side of the junction and 17 on the 3' side.
Accordingly, for the preparation of the preferred des (1-44) t-PA variant a primer having the sequence: ##STR1## is preferably employed. However, it will be apparent that any degree of finger deletion can be accomplished through the use of similar DNA primers. Thus, for example, for deletion mutants encoding increasing carboxy and/or amino terminal portions of the finger region, one would substitute the above primer with one having the sequence: ##STR2## and so on. Thus, by "walking" the finger region deletion from a total deletion (e.g., des 1-44) to decreasing deletions (e.g., des 1-43, des 2-43, des 2-42, and so on), variant t-PA's are provided of varying improved pharmacokinetic parameters relative to natural t-PA. The particular methodology, reagents, etc., which may be employed to prepare various such deletion variants is disclosed below in connection with examples demonstrating the development of CVSVPA-N44 (D22), a plasmid encoding des (1-44) t-PA, or involves techniques known in the art.
Accordingly, appropriate deletion variants of the t-PA gene may be prepared in this general fashion from known t-PA encoding vectors, which deletion mutants may then be further employed to transform appropriate hosts.
b. Host Cell Cultures and Vectors
The vectors and method disclosed herein are suitable for use in host cells over a wide range of prokaryotic and eukaryotic organisms.
In general, or course, prokaryotes are preferred for cloning of DNA sequences in constructing the vectors useful in the invention. For example, E. coli K12 strain 294 (ATCC No. 31446) is particularly useful. Other microbial strains which may be used include E. coli strains such as E. coli B, and E. coli X1776 (ATTC No. 31537). These examples are, of course, intended to be illustrative rather than limiting.
Prokaryotes may also be used for expression. The aforementioned strains, as well as E. coli W3110 (F-, λ-, prototrophic, ATTC No. 273325), bacilli such as Bacillus subtilus, and other enterobacteriaceae such as Salmonella typhimurium or Serratia marcesans, and various pseudomonas species may be used.
In general, plasmid vectors containing replicon and control sequences which are derived from species compatible with the host cell are used in connection with these hosts. The vector ordinarily carries a replication site, as well as marking sequences which are capable of providing phenotypic selection in transformed cells. For example, E. coli is typically transformed using pBR 322, a plasmid derived from an E. coli species (see, e.g., Bolivar, et al., Gene 2:95 (1977)). pBR 322 contains genes for ampicillin and tetracycline resistance and thus provides easy means for identifying transformed cells. The pBR 322 plasmid, or other microbial plasmid or phage must also contain, or be modified to contain, promoters which can be used by the microbial organism for expression of its own proteins.
Those promoters most commonly used in recombinant DNA construction include the B-lactase (penicillinase) and lactose promoter systems (Chang et al., Nature, 375:615 (1978); Itakura, et al., Science, 198:1056 (1977); Goeddel, et al. Nature 281:544 (1979)) and a tryptophan (trp) promoter system Goeddel, et al., Nucleic Acids Res., 8:4057 (1980); EPO Appl Publ No 0036776). While these are the most commonly used, other microbial promoters have been discovered and utilized, and details concerning their nucleotide sequences have been published, enabling a skilled worker to ligate them functionally with plasmid vectors (see e.g., Siebwenlist, et al. Cell 20:269 (1980)).
In addition to prokaryotes, eukaryotic microbes, such as yeast cultures may also be used. Saccharomyces cerevisiase, or common baker's yeast is the most commonly used among eukaryotic microorganisms, although a number of other strains are commonly available. For expression in Saccharomyces, the plasmid YRp7, for example, (Stinchcomb, et al., Nature, 282:39 (1979); Kingsman et al., Gene, 7:141 (1979); Tschemper, et al., Gene, 10:157 (1980)) is commonly used. This plasmid already contains the trpl gene which provides a selection marker for a mutant strain of yeast lacking the ability to grow in tryptophan, for example ATCC No. 44076 or PEP4-1 (Jones, Genetics, 85:12 (1977)). The presence of the trpl lesion as a characteristic of the yeast host cell genome then provides an effective environment for detecting transformation by growth in the absence of tryptophan.
Suitable promoting sequences in yeast vectors include the promoters for 3-phosphoglycerate kinase (Hitzeman, et al., J. Biol. Chem., 255:2073 (1980)) or other glycolytic enzymes (Hess, et al., J. Adv. Enzyme Reg., 7:149 (1968); Holland, et al., Biochemistry, 17:4900 (1978)), such as enolase, glyceraldehyde-3-phosphate dehydrogenase, hexokinase, pyruvate decarboxylase, phosphofructokinase, glucose-6-phosphate isomerase, 3-phosphoglycerate mutase, pyruvate kinase, triosephosphate isomerase, phosphoglucose isomerase, and glucokinase. In constructing suitable expression plasmids, the termination sequences associated with these genes are also ligated into the expression vector 3' of the sequence desired to be expressed to provide polyadenylation of the mRNA and termination. Other promoters, which have the additional advantage of transcription controlled by growth conditions are the promoter region for alcohol dehydrogenase 2, isocytochrome C, acid phosphatase, degradative enzymes associated with nitrogen metabolism, and the aforementioned glyceraldehyde-3-phosphate dehydrogenase, and enzymes responsible for maltose and galactose utilization. Any plasmid vector containing yeast-compatible promoter, origin of replication and termination sequences is suitable.
In addition to microorganisms, cultures of cells derived from multicellular organisms may also be used as hosts. In principle, any such cell culture is workable, whether from vertebrate or invertebrate culture. However, interest has been greatest in vertebrate cells, and propogation of vertebrate cells in culture (tissue culture) has become a routine procedure in recent years [Tissue Culture, Academic Press, Kruse and Patterson, editors (1973)]. Examples of such useful host cell lines are VERO and HeLa cells, Chinese hamster ovary (CHO) cell lines, and W138, BHK, COS-7 and MDCK cell lines. Expression vectors for such cells ordinarily include (if necessary) an origin of replication, a promoter located in front of the gene to be expressed, along with any necessary ribosome binding sites, RNA splice sites, polyadenylation site, and transcriptional terminator sequences.
For use in mammalian cells, the control functions on the expression vectors are often provided by viral material. For example, commonly used promoters are derived from polyoma, Adenovirus 2, and most frequently Simian Virus 40 (SV40). The early and late promoters of SV40 virus are particularly useful because both are obtained easily from the virus as a fragment which also contains the SV40 viral origin of replication (Fiers, et al., Nature, 273:113 (1978). Smaller or larger SV40 fragments may also be used, provided there is included the approximately 250 bp sequence extending from the Hind III site toward the Bgl I site located in the viral origin of replication. Further, it is also possible, and often desirable, to utilize promoter or control sequences normally associated with the desired gene sequence, provided such control sequences are compatible with the host cell systems.
An origin of replication may be provided either by construction of the vector to include an exogenous origin, such as may be derived from SV40 or other viral (e.g. Polyoma, Adeno, VSV, BPV) source, or may be provided by the host cell chromosomal replication mechanism. If the vector is integrated into the host cell chromosome, the latter is often sufficient.
In selecting a preferred host cell for transfection by the vectors of the invention which comprise DNA sequences encoding both variant t-PA and DHFR protein, it is appropriate to select the host according to the type of DHFR protein employed. If wild type DHFR protein is employed, it is preferable to select a host cell which is deficient in DHFR, thus permitting the use of the DHFR coding sequence as a marker for successful transfection in selective medium which lacks hypoxanthine, glycine, and thymidine. An appropriate host cell in this case is the Chinese hamster ovary (CHO) cell line deficient in DHFR activity, prepared and propagated as described by Urlaub and Chasin, Proc. Natl. Acad. Sci. (USA) 77: 4216 (1980).
On the other hand, if DHFR protein with low binding affinity for MTX is used as the controlling sequence, it is not necessary to use DHFR deficient cells. Because the mutant DHFR is resistant to methotrexate, MTX containing media can be used as a means of selection provided that the host cells are themselves methotrexate sensitive. Most eukaryotic cells which are capable of absorbing MTX appear to be methotrexate sensitive. One such useful cell line is a CHO line, CHO-K1 ATCC No. CCL 61.
Satisfactory amounts of human t-PA are produced by cell cultures, however, refinements using a secondary coding sequence serve to enhance production levels even further. The secondary coding sequence comprises dihydrofolate reductase (DHFR) which is affected by an externally controlled parameter, such as methotrexate, thus permitting control of expression by control of the methotrexate (MTX) concentration.
c. Methods Employed
If cells without formidable cell membrane barriers are used as host cells, transfection is carried out by the calcium phosphate precipitation method as described by Graham and Van der Eb, Virology, 52: 546 (1978). However, other methods for introducing DNA into cells such as by nuclear injection or by protoplast fusion may also be used.
If prokaryotic cells or cells which contain substantial cell wall constructions are used, the preferred method of transfection is calcium treatment using calcium chloride as described by Cohen, F.N. et al., Proc. Natl. Acad. Sci. (USA) 69: 2110 (1972).
Construction of suitable vectors containing the desired coding and control sequences employ standard ligation techniques. Isolated plasmids or DNA fragments are cleaved, tailored, and relegated in the form desired to form the plasmids required.
Cleavage is performed by treating with restriction enzyme (or enzymes) in suitable buffer. In general, about 1 ug plasmid or DNA fragments is used with about 1 unit of enzyme in about 20 ul of buffer solution. (Appropriate buffers and substrate amounts for particular restriction enzymes are specified by the manufacturer.) Incubation times of about 1 hour at 37' are workable. After incubations, protein is removed by extraction with phenol and chloroform, and the nucleic acid is recovered from the aqueous fraction by precipitation with ethanol.
If blunt ends are required, the preparation is treated for 15 minutes at 15' C. with 10 units of Polymerase I (Klenow), phenol-chloroform extracted, and ethanol precipitated.
Size separation of the cleaved fragments is performed using 6 percent polyacrylamide gel described by Goeddel, D., et al., Nuclei Acids Res., 8: 4057 (1980).
For ligation approximately equimolar amounts of the desired components, suitably end tailored to provide correct matching are treated with about 10 units T4 DNA ligase per 0.5 ug DNA. (When cleaved vectors are used as components, it may be useful to prevent religation of the cleaved vector by pretreatment with bacterial alkaline phosphatase.)
As discussed above, t-PA variants hereof are preferably produced by means of specific deletion mutation. Deletion mutants useful in the practice of the present invention are formed most readily through the use of specific oligonucleotide sequences which encode the DNA sequence of the desired deletion junctions, as well as a sufficient number of adjacent nucleotides, to provide a sequence of sufficient size and sequence complexity to form a stable duplex on both sides of the deletion junction being traversed.
For analysis to confirm correct sequences in plasmids constructed, the ligation mixtures are used to transform E. coli K 12 strain 294 (ATCC 31446), and successful transformants selected by ampicillin ot tetracycline resistance where appropriate. Plasmids from the transformants are prepared, analyzed by restriction and/or sequenced by the method of Messing et al., Nucleic Acids Res., 9:309 (1981) or by the method of Maxam et al., Methods of Enzymology, 65:499 (1980).
Amplification of DHFR protein coding sequences is effected by growing host cell cultures in the presence of approximately 20-500,000 nM concentrations of methotrexate, a competitive inhibitor of DHFR activity. The effective range of concentration is highly dependent, of course, upon the nature of the DHFR gene, protein and the characteristics of the host. Clearly, generally defined upper and lower limits cannot be ascertained. Suitable concentrations of other folic acid analogs or other compounds which inhibit DHFR could also be used. MTX itself is, however, convenient, readily available and effective.
In the examples which follow, preferred embodiments are disclosed in the form of experiments conducted by applicants to demonstrate the practice and surprising utility of the present invention. It will be appreciated by those of skill that these methods represent those found by the present inventors to work well in the practice of the invention and as such, these experiments in no way represent the only means to achieve the advantages of the invention.
EXAMPLE I
PREPARATION OF DES (1-44) HUMAN t-PA VARIANT
As discussed briefly above, the most convenient method for introducing specific deletions in the finger region of natural t-PA is through site-specific deletion mutagenesis of the underlying cDNA gene sequences. This method employs a single-stranded synthetic "primer" sequence that encodes the desired new sequence. The new primer is hybridized to a single-stranded template bearing complementary sequences, typically a template encoding the gene from which sequences are to be deleted. After the primer is extended through the use of a DNA polymerase, the hybrid molecule is allowed to replicate in a suitable host.
To prepare a des (1-44) t-PA mutant, site-directed deletion mutagenesis was practiced using a starting plasmid which encodes the t-PA cDNA structural gene and a part of the 3' untranslated region. The preparation of this plasmid, pPADHFR-6 (also designated pETPFR), as well as conditions for its expression in suitable hosts and purification of the resultant protein, is described in detail in EPO Application Publication No. 093,619, incorporated herein by reference. A schematic diagram of the steps taken in performing the deletion is shown in FIG. 2. The basic methodology employed is disclosed in Adelman, et al. (1983), DNA, 2:183, incorporated herein by reference.
Plasmid pPADHFR-6 was digested with StuI and EcoRI to release an 826 base pair fragment which included sequences encoding the t-PA presequence through amino acid 203. This fragment was ligated with the vector fragment of SmaI/EcoRI digested M13mp10RF, a replicative form M13 phage vector (see, e.g., Messing, et al. Third Cleveland Symposium on Macromolecules Recombinant DNA, Editor A. Walton, Elsevier, Amsterdam (1981)). The intermediate plasmid, pPA-N44intA, was thus a replicative form of M13 phage which included the portion of the t-PA gene from which the codons for amino acids 1-44 were to be removed by site-directed deletion mutagenesis.
To perform the mutagenesis, an oligonucleotide primer was prepared by a method such as the phosphotriester method of Crea, et al., (1978) Proc. Natl. Acad. Sci. USA, 75:5765. The primer employed to prepare a des (1-44) mutant was as follows: ##STR3##
As will be appreciated, the ten 5' nucleotides of this primer encode presequence amino acids -3 to -1 (gly-ala-arg), whereas the seventeen 3' nucleotides encode amino acids 45 through 49 (SER-VAL-PRO-VAL-LYS). Note that the "TCT" codon was employed for serine-45 in order to retain the BglII site.
Approximately 200 mg of the synthetic oligonucleotide was phosphorylated for 30 minutes at 37° C. in 30 μl of 50 mM-Tris-HCl, pH 7.5, 10 mM MgC12, 10 mM dithiothreitol, 1 mM ATP containing about 8 U of T4 polynucleotide kinase. For heteroduplex formation, about 50 ng single-stranded pPA-N44intA was heated to 95° C. (10 min), and slowly cooled to room temperature (30 min), then to 4° C., in about 40 μl 10 mM Tris-HCl, pH 7.5, 10 mM MgC12, 1 mM dithiothreitol containing 100 ng of the phosphorylated primer. Primer extension was started by the addition of 10 μl ligase buffer containing 2 mM ATP, 0.25 mM each of dGTP, dCTP, dATP, dTTP, 5 U of E. coli polymerase I large (Klenow) fragment and 400 U of T4 DNA ligase. After 1 hour at 15° C. the reaction mixture was used to transform JM101 cells.
Transformation was performed by mixing all of the ligation mixture with 200 μl of competent JM101 cells, followed by incubation on ice for 30' and 5' at 37° C. Then 3.5 ml. 2YT top agar at 55' was mixed with 200 μl. of the phage-saturated cells, 10 μl IPTG (200 mM) and 50 μl×gal and after addition, the cells were plated onto Petri dishes containing 2YT with no drugs.
Colorless plaques were picked and transferred to a microtiter dish containing 100 μl 2YT medium. The inoculated microtiter fluids were stamped on 15 cm diameter LB agar plates overlayed with a lawn of 600 μl JM101 cells in 8 ml 2YT top agar and incubated overnight at 37° C. The formed plaques were transferred to a nitrocellulose disc by physical contact for 1 min. The nitrocellulose disc was treated with 0.5M NaOH, 1.5M NaCl for 3 min and washed twice with 3M NaCl-0.5M Tris HCl pH 7.5 for 15 min and then with 2×SSC for 15 min. Prehybridization mix contains 10 mM Tris pH 7.5, 5 mM EDTA, 0.9M NaCl, 1×Denhardt 0.5 percent NP40, 100 μM ATP, 1 mM sodium pyrophosphate, 1 mM sodium phosphate and 50 μg/ml E. coli tRNA. 1×Denhardt's contains per liter 200 mg Ficoll, 200 mg polyvinylpyrrolidone, 200 mg bovine serum albumin (BSA; fraction V). The disc was baked at 80° C. in vacuo for 90 min. The disc was then incubated for 3 hrs with 6 ml prehybridization fluid in a Petri dish followed by addition of 5×106 cpm labeled primer and hybridized overnight. Selective washing of the disc was performed with 0.4× SSC at 49° C. and after air-drying the disc was exposed to X-ray film. Positively hybridizing clones were further analyzed by dideoxy sequencing. See Adelman, Ibid. From the positive colonies, a recombinant plasmid, designated pPA-N44intA delta, was selected which contained the proper deletion.
In order to replace the mutant gene sequence from the M13 phage into proper expression context into the DHFR-containing expression vector, plasmid pPADHFR6 was digested separately with BgII/KpnI, to isolate the large fragment encoding the DHFR gene, and BstXI/Kpnl, to isolate a 2240 base fragment encoding the 3' end (amino acids 45-527) of natural t-PA. A 400 base fragment bearing the N44 mutation was isolated from pPA-N44intA delta by digestion with BglII/BstXl, and ligated together with the two fragments derived from pPADHFR6. The product of this ligation, designated CVSVPA-N44 D22, was thus a copy of the parental plasmid pPADHFR6, except having codons encoding amino acids 1-44 removed.
EXAMPLE II
TRANSFECTION OF CHO CELLS WITH CVSVPA-N44 (D22)
The recombinant plasmid CVSVPA-N44 (D22) was expressed in DHFR- CHO cells, prepared as discussed above. The CHO cells were grown to approximately 75% confluency, and transfected with approximately 2 μg plasmid DNA (about 1/2 normal miniscreen) which had previously been subjected to RNase in Tris-EDTA buffer. The DNA was brought to 50 mM CaPO 4 /HEPES and this material was employed to transfect the cells generally by the method of Graham et al. (1978), Virology, 52:546. Briefly, the media was removed from the monolayer cells in a 100 mm culture dish, and replaced with about 5 ml of Ham's F12 media with 10% FCS. The calcium-precipitated DNA was put on the cells and allowed to sit at 37° C. for two hours.
After about 2 hours, the cells were glycerol-shocked by removing the old media and adding 1 ml shock solution (20% glycerol in PBS) for about 45 seconds. The cells were then washed with F12 media to remove glycerol and refed with fresh media for about 48 hours. At this point, the cells were split about 1/10 and replaced on selective media (Ham's F12, G- H- T- , with 10% extensively dialyzed FCS). After plating on selective media, the cells were frozen until used for preparation of Des (1-44) t-PA.
EXAMPLE III
PREPARATION OF DES (1-44) HUMAN t-PA
Des 1-44 t-PA was expressed in Chinese hamster ovary (CHO) cells as discussed above. The supernatants were collected, filtered, and stored at -20° C. in the presence of aprotinin. The t-PA was purified from cell supernatants using published procedures (see, e.g. UK patent 2, 119,804; EPO application publication nos. 041,766, 093,619 or 0,199,574, all incorporated herein by reference) or a monoclonal antibody column. In particular, transformed CHO cells were grown to confluency in roller bottles in F12 medium containing 10% FBS, 500 mM MTX, 200 mM glutamine, 20 mM Hepes, 100 U/ml pen-strep, after which time the media was replaced with serum-free medium, and incubation continued for 5-6 days. The cells were separated and the supernatant passed over a Zn-chelating column (see, e.g. EPO publication 0.199,574) and washed with 2 column volumes of 1M NaCl, 50 nM Tris, pH 8.0. The t-PA variant was then eluted with same buffer including 50 mM imidazole, and tubes bearing activity pooled.
This material was then dialyzed into 25 mM Tris, 0.5 M NaCl, pH 8.0, and passed over a lysine-sepharose column. Following washing with 2 column volumes of 0.8M NaCl, 40 mM NaPO4, it was eluted with 50 mM NaPO4, 0.2M arginine, pH 7.2-7.4. Although the concentration of arginine required to elute des 1-44 t-PA from lysine-agarose was similar to the concentration required to elute normal sequence t-PA, it was necessary to load the column very slowly with des 1-44 t-PA to ensure that it would bind.
Protein concentrations were determined by an ELISA, and standardized to amino acid analysis of both des 1-44 t-PA and normal sequence t-PA. Protein purity and homogeneity were analyzed by N-terminal sequencing on a prototype gas/liquid phase sequencer, and by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (PAGE-SDS) with the buffer system of Laemmli (1970) Nature, 227:680. Typically 7 to 17% gradient gels were used and proteins were visualized with the silver-stain technique of Morrissey (1981), Anal. Biochem. 117:307. Natural sequence t-PA was expressed and purified in a similar manner.
Both t-PA and des 1-44 t-PA were purified to homogeneity using identical techniques and each protein exhibited the expected molecular weight on SDS-PAGE. Although synthesized as one polypeptide chain, nonresistant one-chain t-PA can be readily hydrolyzed at the Arg275-Ile276 peptide bond to yield a two-chain form. FIG. 3 shows that in the absence of reducing agents, the apparent Mr's of t-PA and des 1-44 t-PA are approximately 60,000 and 55,000, respectively. When the two-chain forms of the proteins were reduced by the addition of dithiothreitol, t-PA exhibited bands at about 35,000 daltons and a diffuse band from about 30,000 to 34,000 daltons, corresponding to the protease portion of the molecule (residues 275-527), and the amino-terminal finger, growth factor and kringle domains (residues 1-275), respectively. Des 1-44 t-PA exhibited bands at Mr's of about 35,000 and a diffuse band from about 25,000 to 30,000 which corresponds to a protease portion identical to that in t-PA and an amino-terminal domain at a lower molecular weight than the corresponding domain in t-PA. The identification of these bands was confirmed by a western blot using antibodies to the amino-terminal half of t-PA.
Amino-terminal sequencing of samples of both proteins showed that each protein had a minor sequence I-K-G corresponding to residues 276-278, indicating that the samples were in the two-chain form. The other major sequence in the t-PA sample was S-Y-Q, corresponding to residues 1-3. In des 1-44 t-PA the major sequence was S-V-P, which corresponds to residues 45-47 and confirms that the finger domain (residues 1-44) was deleted and that the mutant protein was expressed and processed properly with residue 45 as the new amino terminal.
Although the results of SDS-PAGE and sequence analysis verified that des 1-44 t-PA was a homogeneous protein with the expected molecular weight and sequence, deletion of one domain of the protein may have significant effects on the structure and folding of the rest of the molecule. Although no direct tests are available to examine the secondary and tertiary structure on the molecule, we have determined that limited proteolysis is effective in identifying improperly folded molecules. When the degradation pattern of trypsin-treated t-PA and des 1-44 t-PA were compared no differences were observed (FIG. 4). Although the amino-terminal domain in the des 1-44 t-PA samples (see FIG. 4) has a lower molecular weight than the corresponding domain in t-PA, neither the protease nor the amino-terminal domain of des 1-44 t-PA was more susceptible to proteolysis by trypsin. Proteolysis at higher trypsin t-PA ratios and several ratios of chymotrypsin and pepsin to t-PA also showed no differences in the rate of proteolysis.
EXAMPLE IV
PREPARATION AND UTILIZATION OF EXPRESSION VECTOR FOR RECOMBINANT PRODUCTION OF DES 1-44 GLU 275 t-PA VARIANTS HEREOF
1. Plasmid Constructions
a. Plasmid p1154
1) Plasmid pPADHFR-6
Plasmid pPADHFR-6 (otherwise referred to as pETPFR) was prepared as described, for example, in European Patent Application Publication No. 93619, supra., which is hereby incorporated by reference. See FIG. 1 for perspective details. Superfluously, this plasmid, per se and in transfected form in CHO cells, has been deposited on Dec. 15, 1987 with the American Type Culture Collection, Rockville, Md., USA under ATCC Nos. 40403 and CRL 9606, respectively.
2) Plasmid pCVSVPA-N44 D22
Plasmid pCVSVPA-N44 D22 was prepared as described above. To recapitulate, plasmid pPADHFR-6 (supra.) was digested with StuI and EcoRI to release an 826 base pair fragment which included sequences encoding the t-PA presequence through amino acid 203. This fragment was ligated with the vector fragment of SmaI/EcoRI digested M13mp10RF, the replicative form M13 phage vector (see, e.g., Messing et al., Third Cleveland Symposium on Macromolecules Recombinant DNA, Editor A. Walton, Elsevier, Amsterdam (1981)). The intermediate plasmid, pPA-N44intA, was thus a replicative form of M13 phage which included the portion of the t-PA gene from which the codons for amino acids 1-44 were to be removed by site-directed deletion mutagenesis.
To perform the mutagenesis, an oligonucleotide primer was prepared by a method such as the phosphotriester method of Crea et al., Proc. Natl. Acad. Sci. (USA) 75, 5765 (1978). The primer employed to prepare a des (1-44) mutant was as follows: ##STR4##
As will be appreciated, the ten 5' nucleotides of this primer encode presequence amino acids -3 to -1 (gly-ala-arg), whereas the seventeen 3' nucleotides encode amino acids 45 through 49 (SER-VAL-PRO-VAL-LYS). Note that the "TCT" codon was employed for serine-45 in order to retain the BglII site.
Approximately 200 mg of the synthetic oligonucleotide was phosphorylated for 30 minutes at 37° C. in 30 μl of 50 mM-Tris-HCl, pH 7.5, 10 mM MgCl 2 , 10 mM dithiothreitol, 1 mM ATP containing about 8 U of T4 polynucleotide kinase. For heteroduplex formation, about 50 ng single-stranded pPA-N44intA was heated to 95° C. (10 min), and slowly cooled to room temperature (30 min), then to 4° C., in about 40 μl 10 mM Tris-HCl, pH 7.5, 10 mM MgCl 2 , 1 mM dithiothreitol containing 100 ng of the phosphorylated primer. Primer extension was started by the addition of 10 μl ligase buffer containing 2 mM ATP, 0.25 mM each of dGTP, dCTP, dATP, dTTP, 5 U of E. coli polymerase I large (Klenow) fragment and 400 U of T4 DNA ligase. After 1 hour at 15° C. the reaction mixture was used to transform JM101 cells.
Transformation was performed by mixing all of the ligation mixture with 200 μl of competent JM101 cells, followed by incubation on ice for 30' and 5' at 37° C. Then 3.5 ml 2YT top agar at 55° C. was mixed with 200 μl of the phage-saturated cells, 10 μl IPTG (200 mM) and 50 μl×gal and after addition, the cells were plated onto Petri dishes containing 2YT with no drugs.
Colorless plaques were picked and transferred to a microtiter dish containing 100 μl 2YT medium. The inoculated microtiter fluids were stamped on 15 cm diameter LB agar plates overlayed with a lawn of 600 μl JM101 cells in 8 ml 2YT top agar and incubated overnight at 37° C. The formed plaques were transferred to a nitrocellulose disc by physical contact for 1 min. The nitrocellulose disc was treated with 0.5M NaOH, 1.5M NaCl for 3 min and washed twice with 3M NaCl-0.5M Tris-HCl pH 7.5 for 15 min and then with 2×SSC for 15 min. Prehybridization mix contains 10 mM Tris pH 7.5, 5 mM EDTA, 0.9M NaCl, 1×Denhardt 0.5 percent NP40, 100 μM ATP, 1 mM sodium pyrophosphate, 1 mM sodium phosphate and 50 μg/ml E. coli tRNA. 1×Denhardt's contains per liter 200 mg Ficoll, 200 mg polyvinylpyrrolidone, 200 mg bovine serum albumin (BSA; fraction V). The disc was baked at 80° C. in vacuo for 90 min. The disc was then incubated for 3 hrs with 6 ml prehybridization fluid in a Petri dish followed by addition of 5×10 6 cpm labeled primer and hybridized overnight. Selective washing of the disc was performed with 0.4×SSC at 49° C. and after air-drying the disc was exposed to X-ray film. Positively hybridizing clones were further analyzed by dideoxy sequencing. See Adelman, supra. From the positive colonies, a recombinant plasmid, designated pPA-N44intA delta, was selected which contained the proper deletion.
In order to replace the mutant gene sequence from the M13 phage into proper expression context into the DHFR-containing expression vector, plasmid pPADHFR-6 was digested separately with BglI/KpnI, to isolate the large fragment encoding the DHFR gene, and BstXI/KpnI, to isolate a 2240 base fragment encoding the 3' end (amino acids 45-527) of natural t-PA. A 400 base fragment bearing the N44 (des 1-44) mutation was isolated from pPA-N44intA delta by digestion with BglII/BstXI, and ligated together with the two fragments derived from pPADHFR-6. The product of this ligation, designated CVSVPA-N44 D22, was thus a copy of the parental plasmid pPADHFR-6, except having codons encoding amino acids 1-44 removed.
3) Plasmid pPADHFR-6 2C9
Plasmid pPADHFR-6 2C9 was prepared as described, for example, in U.S. Ser. No. 07/071,506, filed July 9 1987 and its parents-see supra. In summary, human t-PA DNA was obtained from plasmids pPADHFR-6 (also designated pETPFR) and pA25E10. The preparation of these two t-PA plasmids is described in European Patent Application Publication No. 093619, supra.
Plasmid pA25E10 contains sequences coding for the last 508 amino acids of the t-PA gene and 772 base pairs of the 3' untranslated region. This plasmid was digested with SacI and BglII to produce a 744 base pair fragment which was isolated by standard methods as previously described. This fragment contains the codons for t-PA amino acids 411 through 527 and includes part of the 3' untranslated region.
Plasmid pPADHFR-6 contains the entire structural gene for t-PA and part of the 3' untranslated region. This plasmid was digested with SacI and BglII to produce a 1,230 base pair fragment which was isolated. This fragment contains codons for the first 410 amino acids of the mature form of t-PA.
These fragments were ligated together using standard methods and digested with BglII. A 1,974 base pair fragment containing codons for the entire mature t-PA sequence plus part of the 3' untranslated region was isolated. Double stranded M13mp8, (Messing, supra.) was digested with BamHI and annealed to the BglII digested t-PA to form M13mp8PABglII. E. coli JM 101 cells (ATCC No. 33876) were transformed with the double stranded replicative form of M13mp8PABglII. The single stranded and double stranded (RF) forms of M13mp8PABglII may be isolated from E. coli JM 101 cells infected with this phage. The single stranded form was used for the site specific mutagenesis of t-PA.
The human t-PA structural gene was modified by site specific mutagenesis to express t-PA with amino acid substitution at the appropriate various position. A synthetic oligonucleotide was prepared such as by the solid phase phosphotriester method of Crea et al. (supra.). Among the synthetic primers that were prepared and used for such site specific mutagenesis was: ##STR5##
The procedure described hereinafter, was used to generate different t-PA clones containing the mutated sequence of the synthetic primers. The general method used is that of Adelman (supra.), incorporated herein by reference. For example, 3M13RF2C9 was generated by the use of the above primer. Purified M13 RF DNA from the mutated t-PA gene was prepared from E. coli JM101 cells. Subsequently, DNA fragments containing the mutated t-PA DNA sequence were used to construct expression vectors for the mutated t-PA.
50 ng of a synthetic oligonucleotide was phosphorylated for 30 min at 37° C. in 10 μl of 50 mM Tris-HCl pH 7.5, 10 mM MgCl 2 , 10 mM dithiothreitol, 1 mM ATP containing 8 U of T4 polynucleotide kinase. For use as a probe, 400 ng of the synthetic oligonucleotide was phosphorylated as above except that ATP was replaced with 60 mCi [γ 32 -P]-ATP (3000 μCi/mmol) resulting in approximately 50 to 60×10 6 cpm/400 ng of 24-mer. For heteroduplex formation, 10 ng single stranded M13mp8PABglII was heated to 95° C. (10 min), and slowly cooled to room temperature (30 min) in 40 μl 10 mM Tris-HCl pH 7.5, 10 mM MgCl 2 , 1 mM dithiothreitol containing 10 ng of the phosphorylated primer and 50 ng of EcoRI-digested M13mp8PABglIIRF large fragment. Primer extension was started by the addition of 10 μl ligase buffer containing 2 mM ATP, 0.25 mM each of dGTP, dTTP, dCTP and dATP, 5 U of E. coli DNA polymerase I large fragment and 400 U of T4 DNA ligase. After 1 hr at 12° C. the reaction mixture was used to transform E. coli JM101 cells.
Transformation was accomplished by mixing 10 μl of the ligation mixture with 200 μl of competent JM101 cells, followed by incubation for 30 min on ice and 5 min at 37° C. Then 3.5 ml 2YT top agar at 55° C. was mixed with 200 μl saturated JM101 cells, 10 μl IPTG (200 mM) and 50 μl×gal and after addition of the transformed cells plated 9 cm on Petri dishes containing LB with no drugs.
Colorless plaques were picked and transferred to a microtiter dish containing 100 μl 2YT medium. The inoculated microtiter fluids were stamped on 15 cm diameter LB agar plates overlayed with a lawn of 600 μl JM101 cells in 8 ml 2YT top agar and incubated overnight at 37° C. The formed plaques were transferred to a nitrocellulose disc by physical contact for 1 min. The nitrocellulose disc was treated with 0.5M NaOH, 1.5M NaCl for 3 min and washed twice with 3M NaCl-0.5M Tris-HCl pH 7.5 for 15 min and then with 2×SSC for 15 min. Prehybridization mix contains 10 mM Tris pH 7.5, 5 mM EDTA, 0.9M NaCl, 1×Denhardt 0.5 percent NP40, 100 μM ATP, 1 mM sodium pyrophosphate, 1 mM sodium phosphate and 50 μg/ml E. coli tRNA. 1×Denhardt's contains per liter 200 mg Ficoll, 200 mg polyvinylpyrrolidone, 200 mg bovine serum albumin (BSA; fraction V). The disc was baked at 80° C. in vacuo for 90 min. The disc was then incubated for 3 hrs with 6 ml prehybridization fluid in a Petri dish followed by addition of 5×10 6 cpm labeled primer and hybridized overnight. Selective washing of the disc was performed with 0.4×SSC at 49° C. and after air-drying the disc was exposed to X-ray film. Positively hybridizing clones were further analyzed by dideoxy sequencing. See Adelman, (supra.).
Vector fragment designated as fragment 1 was obtained by isolating the large fragment generated by digestion of pPADHFR-6 with BglII and BstEII. A fragment designated as fragment 2 obtained by isolating the 400 base pair t-PA fragment obtained from the digestion of pPADHFR-6 with BglII and BstXI. A 1,141 base pair t-PA fragment containing the desired mutations (fragment 3) was obtained by digesting RF DNA from the mutant t-PA clones (supra.) with BstXI and BstEII. Fragments 1 and 2 were litigated with each fragment 3. The DNA mixtures were used to transform E. coli . From each of the transformants, the respective eukaryotic expression vectors were obtained, for example: pPADHFR-6 2C9.
4) Final Construction of p1154
Plasmid pETPFR was digested with the restriction enzymes Bg1II and ApaI and the fragments fractionated by agarose gel electrophoresis. The 6.0 kb fragment containing the t-PA preprocoding region, the SV40 early promoter, β-lactamase, and DHFR genes was cut out from the gel and electroeluted.
Plasmid pCVSVPA-N44 D22 was digested with Bg1II and ScaI, the fragments fractionated by acrylamide gel electrophoresis, and the band containing the 0.63 kb fragment (representing the coding sequences for the growth factor, kringle one and kringle two [partial] domains of t-PA) was cut out and electroeluted.
Plasmid pPADHFR-6 2C9 was digested with ScaI and ApaI, and the 0.63 kb fragment containing the coding sequences for kringle two (partial) and the protease (with the Glu 275 mutation) domains was purified by acrylamide gel electrophoresis and electroelution.
The three thus isolated, purified fragments were incubated in the presence of T4 DNA ligase and rATP to produce the plasmid p1154, containing sequences coding for a t-PA molecule lacking residues 1-44 (finger domain deletion) and incorporating an Arg 275→Glu mutation (single chain mutant). See FIG. 11.
EXAMPLE V
Preparation of Other Domain Deletion Variants of t-PA
The construction of plasmid pCVSVPA-N44 D22 is described in detail supra. in connection with the description of the preparation of plasmid p1154.
Likewise, site directed mutagenesis experiments are discussed in detail supra. in connection with the preparation of plasmid pPADHFR-6 2C9.
The des 44-84 growth factor domain deletion, des 92-179 Kringle 1 domain deletion, and des 174-261 Kringle 2 domain deletion were also made by site-directed mutagenesis using the following oligonucleotides: ##STR6## (The delta marks indicate the site of the deleted sequence.) and these used to prepare expression plasmids in a manner analogous to the des 1-44 construction supra., except that mutagenesis was performed on the 1.4 kb BglII/ApaI fragment (in a single stranded vector) containing the bulk of the t-PA coding sequences-See FIG. 11. Also in a manner analogous to the des 1-44 construction, the des 44-84 and des 92-179 mutations could, in principle, also be isolated on BglII/ScaI fragments and joined to the Glu275 mutations and the t-PA C-terminal coding sequences on the 0.63 kb ScaI/ApaI fragment, thus creating plasmids similar to p1154 as described supra. These plasmids are used to transfect appropriate cells and the corresponding t-PA variant produced as described supra.
EXAMPLE VI
DEMONSTRATION OF IN VITRO PROTEASE AMIDOLYTIC ACTIVITY OF DES (1-44) t-PA
The activity of des (1-44) t-PA in a protease amidolytic assay was compared to that of natural t-PA using the S-2288 paranitroanilide chromogenic substrate (Helena Labs). The S-2288 paranitroanilide substrate provides a direct measurement of protease amidolytic activity. The kinetic constants for t-PA and des 1-44 t-PA were determined with the S-2288 substrate using an H-P diode array spectrophotometer (HP8451-A). Hydrolysis of the substrate was measured continuously at two substrate concentrations (1.0 mM and 0.1 mM) while the protein concentrations were held constant at 23 nM in a buffer composed of 0.05M Tris-HCl, 0.12M NaCl, 0.01% Tween 80, pH 7.4. Using the differential form of the Michaelis-Menten equation and a non-linear regression the Km and Vmax were calculated from the curves of the progress of the reaction.
Both des 1-44 t-PA and normal sequence t-PA exhibited similar specific activity using the small synthetic S-2288 substrate, H-D-isoleucyl-L-prolyl-L-arginine p-nitroanilide. As shown in Table 1, the kcat and Km of the two enzymes were within experimental error of each other, which indicated that the protease portion of the molecule has normal function and that the finger domain has no effect on the hydrolysis of small molecular weight substrates.
TABLE 1______________________________________KINETIC CONSTANTS FOR WILD TYPE t-PAAND DES 1-44 t-PA with S-2288 .sup.k cat .sup.K m .sup.k cat/.sup.K m (sec.sup.-1) (mM) (sec.sup.-1 mM.sup.-1)______________________________________Wild type t-PA 17.9 0.33 54.2Des 1-44 t-PA 17.1 0.28 61.1______________________________________
EXAMPLE VII
DEMONSTRATION OF IN VITRO PLASMINOGEN ACTIVATION BY DES (1-44), t-PA
The ability of t-PA to activate plasminogen can be measured in an in vitro assay by preincubating t-PA and plasminogen and then adding the plasmin specific substrate H-D-valyl-H-leucyl-H-lysine-p-nitronilide (S-2251). The maximum rate of this reaction is observed in the presence of fibrin(ogen) or fragments of fibrin(ogen) which act as stimulators of the reaction.
The plasmin specific substrate S-2251 was used in a two-stage assay to measure the ability of the sample to activate plasminogen. Fibrin clots were made by incubating the sample with 0.02 ml of a 20 mg/ml fibrinogen solution with 1U of thrombin in a total volume of 0.12 ml of 0.05M Tris-HCl, 0.12M NaCl, 0.01% Tween 80, pH 7.4 for 30 min. at 37' C. Alternatively, the thrombin could be omitted and fibrinogen used as the stimulator. Glu-plasminogen solution, 0.03 ml of a 2.1 mg/ml solution, was then added. After 10 min at 37' C., 0.35 ml of 2.86 mM S-2251 in 0.037M Tris, 0.86 NaCl, 0.007% Tween 80, pH 7.4) were added. This mixture was incubated for five minutes then the reaction was stopped by the addition of 0.1 ml of 50% glacial acetic acid. Absorbance at 405 nm was measured. The activity was expressed as the change in absorbance per nanogram per minute in the presence of substrate.
The assay was run as described, along with an additional set of samples which did not contain fibrin clots. The stimulation is the ratio of the specific activity of the sample containing fibrin and the specific activity of the sample not containing fibrin.
In various assays (see Table 2 and FIG. 4), the maximum specific activity obtained with des 1-44 t-PA in the presence of fibrin was slightly greater than 50% of the rate obtained with normal sequence t-PA. The activity of both t-PA and des (1-44) t-PA increased about 50-fold in the presence of fibrin. In Table 2, the value for "stem" compares the stimulation seen in the presence of fibrinogen versus no fibrinogen.
TABLE 2______________________________________ +Fgn rel Stim______________________________________With Fibrinogen 100% 100 50% 70.2With Fibrin Clots 100% 100 56% 80.4______________________________________
In order to further compare the ability of des 1-44 t-PA to activate plasminogen in the presence of fibrin(ogen), it was compared to t-PA in an assay which measures the ability of t-PA and saturating plasminogen to lyse a fibrin clot. In this assay, des 1-44 t-PA exhibited only 35% of the activity observed with normal t-PA (Table 3). These results suggest that there may be a defect in the ability of des 1-44 t-PA to interact properly with fibrin.
TABLE 3______________________________________ACTIVITY OF r-PA and des 1-44 t-PA t-PA des 1-44 t-PA______________________________________Clot lysis (relative units) 1.0 0.18______________________________________
The binding of des 1-44 t-PA to fibrin was monitored using a modification of the method of Rijken et al. (1982 J. Biol. Chem., 257:2920). Samples were mixed with various concentrations of human plasminogen-free fibrinogen, in the presence of 1 mg/ml human serum albumin (from J E M Research, Inc., Kensington, Md.) to prevent nonspecific adsorption. The total reaction volume was 1 ml and the buffer was composed of 0.05M Tris-HCl, 0.12M NaCl, 0.01% Tween 80, pH 7.4. One unit of thrombin (from Sigma Chemical Co., St. Louis, Mo.) was added and the mixtures were clotted for one hour at 37' C. The clots were physically removed by centrifugation at 10,000 rpm for 5 min and an aliquot of the supernatant was then assayed for remaining t-PA content by either an activity assay or an ELISA.
The results are shown in FIG. 5. As will be appreciated, the des (1-44) exhibited a much reduced ability to bind fibrin. Although the binding to fibrin was so weak that a dissociation constant could not be obtained, it was estimated that the dissociation was at least 10 fold higher than that for natural t-PA ("RIK"). Thus, fibrin binding is not required in order to retain efficacy of the t-PA activity.
EXAMPLE VIII
IN VIVO CLOT LYSING ACTIVITY OF DES (1-44) t-PA VERSUS NATURAL t-PA
An in vivo experiment was performed in rabbits to demonstrate the dose response of natural t-PA (designated RIK) versus the Des (1-44) t-PA variant. Thrombolytic activities were determined in rabbits using a extracorporeal shunt which contained a thrombus labeled with I-125 fibrinogen. Lysis was measured by the disappearance of radioactivity, measured by an external sodium iodine crystal. The wild type t-PA was given as a 10% bolus with the remainder of the dose infused over the following 90 min. The des (1-44) t-PA was tested at single dose of 0.064 mg/kg using a 0.03 mg/kg bolus followed by an infusion of 0.034 mg/kg for 90 min. All lysis was determined at the end of the 90 min. infusion.
As can be seen in FIG. 6, in an in vivo assay, the des (1-44) t-PA variant exhibited surprisingly high clot lysing activity, within the standard error of natural t-PA. This finding was particularly surprising in light of the in vitro assay results wherein the lysis activity reflected a lower lytic activity for the N44 variant. However, such in vitro experiments failed to take into account the increased half-life of the variant.
In a second type of assay, the two species were compared in terms of percent lysis versus time. The results are shown in FIG. 7 wherein comparable lysis rates were graphed for the 0.3 mg/kg wild type rt-PA dose and for the 0.064 mg/kg des (1-44) rt-PA. As will be appreciated, the activity with time of the des (1-44) variant (N44) closely paralleled the activity of natural t-PA (RIK).
In FIG. 8 is shown the time course of the plasma concentration of the two forms of rt-PA from the foregoing study. Concentrations were determined by a polyclonal ELISA which detects both forms of rt-PA with equal activity. Blood samples were collected on EDTA and an irreversible inhibitor of rt-PA, D-Phe-Pro-Arg-chloromethyl ketone, was added; this inhibitor blocks in vitro formation of t-PA complexes with plasma protease inhibitors. These complexes have significantly decreased immunoreactivity. As will be appreciated, the N44 variant generated a much higher plasma concentration than natural t-PA with a much lower initial and total dose.
EXAMPLE IX
PHARMACOKINETIC STUDIES
Comparative pharmacokinetic studies were performed in rabbits. I-125 labeled test t-PA, either wild type or N44 variant, 5 uCi/kg with a specific activity of 5 to 10 uCi/ug, and carrier wild type t-PA, 1.0 mg/kg, were coinjected, serial blood samples were collected, plasma prepared and the TCA (trichloroacetic acid) precipitable counts were determined at each time point. TCA precipitation was used in order to remove any small metabolites which appear at later times due to degradation of t-PA by the liver. The plasma concentration time curve for rt-PA was fit to a biexponential equation C-Aexp(-alphaXt)+Bexp(-betaXt). The curve for the des (1-44) rt-PA was fit to a monoexponential equation C-Aexp(-alphaXt). The clearance (Cl) was calculated by the formula Cl-DOSE/AUC, where AUC is the area under the plasma concentration time curve.
As can be seen from the results obtained, displayed below in Table 4 and plotted in FIG. 9, in a rabbit test system, the natural t-PA sample, rt-PA, exhibited a clearance rate of about 8.4 ml/min/kg, with a standard deviation of about 0.92, and a half-life (tl/2a) of about 3.1 minutes, with a standard deviation of about 0.55.
TABLE 4__________________________________________________________________________PHARMACOKINETIC PARAMETERS OF AN I.V. BOLUS DOSEOF I-125 rT-PA, IN RABBITS DOSE = 5 uC/kg I-125rT-PA COINJECTED WITH 1 mg/kg COLD rt-PA #A #C #E #G MEAN S.D.__________________________________________________________________________B0 30144.320 32920.033 27005.306 31340.936 30352.649 2504.415t1/2b 33.236 23.987 31.782 26.467 28.868 4.365rsq 0.973 0.963 0.997 0.959 0.973 0.017A0 247990 306059 255904 290852 275201 27748.860t1/2a 3.716 2.645 3.334 2.575 3.067 0.552rsq 0.999 0.991 0.983 0.971 0.986 0.012AUC × 10.sup.- 6 26.609 21.106 23.505 21.128 23.087 2.604AUMC × 10.sup.- 6 789.510 452.925 637.710 525.828 601.493 146.583VDSS ml/kg 209.553 197.899 232.427 213.466 213.336 14.342CL ml/min/kg 7.063 9.222 8.567 8.577 8.357 0.916__________________________________________________________________________
However, with the des (1-44) variant, N44, as shown below in Table 5 and in FIG. 9, a clearance rate of about 0.48 ml/min/kg (S.D. -0.02) and a half-life of about 53.7 minutes (S.D. -6.58), was observed.
TABLE 5__________________________________________________________________________PHARMACOKINETIC PARAMETERS OF A BOLUS DOSEOF I-125 N-44, IN RABBITS DOSE = 5 uC/kgI-125 N44, COINJECTED WITH 1 mg/kg COLD rT-PA #b #d #f #h MEAN s.d.__________________________________________________________________________A0 234100 245900 183000 202300 216300 28870.000lambda0 0.014 0.015 0.011 0.012 0.013 0.002t1/2 50.220 46.310 60.740 57.370 53.660 6.575rsquare0 0.984 0.914 0.980 0.945 0.956 0.033AUC × 10.sup.- 6 171.400 170.900 158.600 172.400 168.300 6.552AUMC × 10.sup.- 6 12610.000 12050.000 13800.000 14740.000 13300.000 1205.000VDSS ml/kg 34.540 33.200 44.190 39.890 37.960 5.060CL ml/min/kg 0.470 0.471 0.508 0.467 0.479 0.019__________________________________________________________________________
Pharmacokinetic analyses were repeated as above except that, instead of using natural t-PA as carrier for the labeled N44 variant, the variant N44 (non-radioactive) itself was employed at a concentration of 1 mg/kg. The results are shown below in Table 6 and FIG. 10. As will be appreciated, using the N44 carrier a half-life of about 73.1 minutes (S.D. -1.22) was observed, with a clearance rate of about 0.42 ml/min/kg (S.D. -0.03).
TABLE 6__________________________________________________________________________PHARMACOKINETIC PARAMETERS OF A BOLUS DOSEOF I-125 N-44, IN RABBITS DOSE = 5 uC/kgI-125 N44 COINJECTED WITH 1 mg/kg COLD N44 #a #b #c MEAN s.d.__________________________________________________________________________A0 197800 197000 221500 205400 13900.00lambda0 0.01 0.01 0.01 0.01 0.00t1/2 71.68 73.81 73.76 73.08 1.22rsquare0 0.98 0.97 0.98 0.98 0.01AUC × 10.sup.- 6 200.10 205.10 233.70 213.00 18.14AUMC × 10.sup.- 6 21470.00 22810.00 25870.00 23380.00 2258.00VDSS ml/kg 47.17 47.72 41.68 45.52 3.34CL ml/min/kg 0.44 0.43 0.38 0.42 0.03__________________________________________________________________________
Based on the foregoing clearance rates and half-lives observed in the rabbit test animals, it can be readily predicted that a similar or greater half-life, as well as a similar or lower clearance rate, will be obtained in man.
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Disclosed herein are improved processes for preparing variant human t-PA proteins exhibiting improved pharmacokinetic properties relative to natural t-PA. One such illustrated variant, devoid of amino acids corresponding to amino acids 1 through 44 of natural t-PA, is shown to exhibit a plasma half-life of greater than about 15 times the plasma half-life to natural t-PA, as well as a clearance rate of less than about 1/10 the clearance rate of natural t-PA. Also disclosed are improved processes for treating vascular disease employing pharmaceutical compositions which incorporate therapeutically effective amounts of such t-PA variants with pharmaceutically acceptable diluents or excipients.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. provisional application Serial No. 60/202,131 filed May 5, 2000, the contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to novel substituted diamine derivatives, pharmaceutical compositions containing them and intermediates used in their manufacture. More particularly, the compounds of the invention are motilin receptor antagonists useful for the treatment of associated conditions and disorders such as gastrointestinal reflux disorders, eating disorders leading to obesity and irritable bowel syndrome.
BACKGROUND OF THE INVENTION
[0003] In mammals, the digestion of nutrients and the elimination of waste are controlled by the gastrointestinal system. Within this system, there are a number of natural peptides, ligands, enzymes, and receptors which play a vital role and are potential targets for drug discovery. Modifying the production of, or responses to these endogenous substances can have an effect upon the physiological responses such as diarrhea, nausea, and abdominal cramping. One example of an endogenous substance which affects the gastrointestinal system is motilin.
[0004] Motilin is a peptide of 22 amino acids which is produced in the gastrointestinal system of a number of species. Although the sequence of the peptide varies from species to species, there are a great deal of similarities. For example, human motilin and porcine motilin are identical; while motilin isolated from the dog and the rabbit differ by five and four amino acids respectively. Motilin induces smooth muscle contractions in the stomach tissue of dogs, rabbits, and humans as well as in the colon of rabbits. Apart from local gastrointestinal intestinal tissues, motilin and its receptors have been found in other areas. For example motilin has been found in circulating plasma, where a rise in the concentration of motilin has been associated with gastric effects which occur during fasting in dogs and humans. Itoh, Z. et al. Scand. J. Gastroenterol. 11:93-110, (1976); Vantrappen, G. et al. Dig. Dis Sci 24, 497-500 (1979). In addition, when motilin was intravenously administered to humans it was found to increase gastric emptying and gut hormone release. Christofides, N. D. et al. Gastroenterology 76:903-907, 1979.
[0005] Aside from motilin itself, there are other substances which are agonists of the motilin receptor and which elicit gastrointestinal emptying. One of those agents is the antibiotic erythromycin. Even though erythromycin is a useful drug, a great number of patients are affected by the drug's gastrointestinal side effects. Studies have shown that erythromycin elicits biological responses that are comparable to motilin itself and therefore may be useful in the treatment of diseases such as chronic idiopathic intestinal pseudo-obstruction and gastroparesis. Weber, F. et al., The American Journal of Gastroenterology, 88:4, 485-90 (1993).
[0006] Although motilin and erythromycin are agonists of the motilin receptor, there is a need for antagonists of this receptor as well. The nausea, abdominal cramping, and diarrhea which are associated with motilin agonists are unwelcome physiological events. The increased gut motility induced by motilin has been implicated in diseases such as Irritable Bowel Syndrome and esophageal reflux. Therefore researchers have been searching for motilin antagonists.
[0007] One such antagonist is OHM-11526. This is a peptide derived from porcine motilin which competes with both motilin and erythromycin for the motilin receptor in a number of species, including rabbits and humans. In addition, this peptide is an antagonist of the contractile smooth muscle response to both erythromycin and motilin in an in vitro rabbit model. Depoortere, I. et al., European Journal of Pharmacology, 286, 241-47, (1995). Although this substance is potent in that model (IC 50 1.0 nM) it is a peptide and as such offers little hope as an oral drug since it is susceptible to the enzymes of the digestive tract. Zen Itoh, Motilin, xvi ( 1990). Therefore it is desirable to find other non-peptidic agents which act as motilin antagonists. The compounds of this invention are such agents.
[0008] The compounds of this invention are non-peptidyl motilin antagonists with potencies and activities comparable to known peptidyl motilin antagonists. These compounds compete with motilin and erythromycin for the motilin receptor site in vitro. In addition, these compounds suppress smooth muscle contractions induced by motilin and erythromycin with activities and potencies comparable to OHM 11526 in an in vitro model.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to compounds of the formula (I):
[0010] wherein
[0011] R 1 is selected from the group consisting of hydrogen, aryl, aralkyl, heterocyclyl, diarylalkyl, heterocyclyl-alkyl, and lower alkyl; wherein the alkyl, aryl or heterocyclyl moieties in the foregoing groups may be substituted with one or more substituents independently selected from halogen, hydroxy, nitro, carboxy, cyano, amino, dialkylamino, lower alkoxy, lower alkyl, tri-halomethyl, alkylamino, carboxy and alkoxycarbonyl;
[0012] R 2 is selected from the group consisting of aryl, aralkyl, cycloalkyl, cycloalkyl-alkyl, heterocyclyl, heterocyclyl-alkyl, diarylalkyl, aminoalkyl, tri-halomethyl, arylamino and lower alkyl; wherein the alkyl, aryl, heterocyclyl-alkyl, heterocyclyl, or amino moieties in the foregoing groups may be substituted with one or more substituents independently selected from halogen, hydroxy, nitro, cyano, amino, dialkylamino, lower alkoxy, lower alkyl, tri-halomethyl, alkylamino, phenyl, carboxy, carboxyalkyl and alkoxycarbonyl;
[0013] X 1 , X 2 , X 3 and X 4 are independently absent or selected from the group consisting of CO and SO 2 ; provided that at least one of X 1 or X 2 and at least one of X 3 or X 4 is CO or SO 2 ;
[0014] alternatively R 1 , R 2 and X 1 can be taken together (with the amine nitrogen) to form a monocyclic or fused bicyclic or tricyclic secondary amine ring structure; wherein the monocyclic or fused bicyclic or tricyclic secondary amine ring structure may be optionally substituted with one or more substituents independently selected from halogen, oxo, nitro, cyano, amino, alkylamino, dialkylamino, trialkylamino, lower alkoxy, lower alkyl, tri-halomethyl, carboxy, acetyloxy, alkoxycarbonyl, aryl, aralkyl andr heterocyclyl;
[0015] A is selected from the group consisting of lower alkyl, lower alkenyl, cycloalkyl, cycloalkyl-alkyl, alkyl-cycloalkyl, cycloalkenyl, cycloalkenyl-alkyl, alkyl-cycloalkenyl, alkyl-cycloalkyl-alkyl; alkyl-aryl-alkyl, alkyl-aryl, aryl-alkyl and phenyl; where, in each case, the A group may optionally be substituted with one or more substituents selected from R 7 ;
[0016] where R 7 is selected from alkyl, tri-halomethyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heterocyclyl-alkyl, diarylalkyl, aminoalkyl, or arylamino; wherein the alkyl, aryl, heterocyclyl-alkyl, heterocyclyl, or amino moieties in the foregoing groups may be substituted with one or more substituents independently selected from halogen, hydroxy, nitro, cyano, amino, dialkylamino, lower alkoxy, lower alkyl, tri-halomethyl, alkylamino, phenyl, carboxy and alkoxycarbonyl;
[0017] provided that A is not −1,3-cyclopentyl-1-ene-alkyl;
[0018] R 3 is selected from the group consisting of hydrogen, aryl, heterocyclyl, aralkyl, diarylalkyl, heterocyclo-alkyl, tri-halomethyl, alkylamino, arylamino and lower alkyl; wherein the aryl, heterocyclyl, aralkyl, diarylalkyl, heterocyclyl-alkyl, alkylamino, arylamino or lower alkyl group may be substituted with one or more substituents independently selected from halogen, nitro, cyano, amino, dialkylamino, lower alkoxy, lower alkyl, tri-halomethyl, carboxy and alkoxycarbonyl;
[0019] Y is selected from the group consisting of —O—, —NH—, —S— and —SO 2 —;
[0020] n is an integer from 0 to 5;
[0021] R 4 is selected from the group consisting of hydrogen, amino, alkylamino, dialkylamino, N-alkyl-N-aralkyl-amino, trialkylamino, dialkylaminoalkoxyalkyl, heterocyclyl, heterocyclyl-alkyl, oxo-substituted heterocyclyl and lower alkyl-substituted heterocyclyl;
[0022] R 5 is selected from the group consisting of hydrogen, halogen, nitro, cyano, amino, alkylamino, dialkylamino, trialkylamino, lower alkoxy, lower alkyl, tri-halomethyl, carboxy and alkoxycarbonyl;
[0023] and the pharmaceutically acceptable salts, esters and pro-drug forms thereof.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Relative to the above generic description, certain compounds of the general formula are preferred.
[0025] where p and t are integers from 1-6. More preferably, R 4 is selected from the group consisting of hydrogen, 4-morpholinyl, 1-pyrrolidinyl, 2-oxo-pyrrolidin-1-yl, 2-(1-methylpyrrolidinyl), 1-piperazinyl, 1-piperidinyl, di(methyl)aminoethyloxyethyl, N-methyl-N-benzyl-amino, di(methyl)amino and diethylamino. More preferably still, R 4 is selected from the group consisting of hydrogen, 4-morpholinyl, 1-pyrrolidinyl, 1-piperazinyl, 1-piperidinyl, di(methyl)amino and di(ethyl)amino. More referably still, R 4 is selected from the group consisting of hydrogen, 4-morpholinyl, 1-pyrrolidinyl, 1-piperidinyl and di(methyl)amino. Most preferably, R 4 is selected from the group consisting of hydrogen, 4-morpholinyl, 1-pyrrolidinyl and 1-piperidinyl;
[0026] Preferably R 5 is selected from the group consisting of hydrogen and lower alkyl. More preferably R 5 is selected from the group consisting of hydrogen and methyl.
[0027] In a preferred embodiment of the present invention are those compounds of general formula (I) wherein:
[0028] R 1 is selected from the group consisting of hydrogen, aralkyl, heterocyclyl and heterocyclyl-alkyl; where the aralkyl, heterocyclyl or heterocyclyl-alkyl may be substituted with one or more substituents independently selected from halogen, lower alkyl, lower alkoxy, tri-halomethyl, hydroxy or nitro;
[0029] R 2 is selected from the group consisting of alkyl, tri-halomethyl, aryl, aralkyl, arylamino, biphenyl, cycloalkyl, cycloalkyl-alkyl, heterocyclyl and heterocyclyl-alkyl; where the aryl, aralkyl or heterocyclyl group may be substituted with one or more substituents independently selected from halogen, lower alkoxy, nitro, carboxy, carboxyalkyl, hydroxy, phenyl, diphenylmethyl, tri-halomethyl or trihaloalkylacetyl;
[0030] X 1 , X 2 , X 3 and X 4 are independently absent or selected from the group consisting of CO and SO 2 ; such that at least one of X 1 or X 2 and at least one of X 3 or X 4 is CO or SO 2 ;
[0031] A is selected from the group consisting of lower alkyl, alkyl-cycloalkyl, cycloalkyl-alkyl, -cycloalkyl, -cycloalkenyl-, cycloalkenyl-alkyl- and -aryl-alkyl-; where the alkyl moiety in the foregoing groups may be substituted with one or more substituents independently selected from aralkyl or cycloalkyl;
[0032] provided that A is not −1,3-cyclopentyl-1-ene-alkyl;
[0033] R 3 is selected from the group consisting of hydrogen, aryl, aralkyl and arylamino; where the aryl or aralkyl group may be substituted with one or more substituents independently selected from halogen, lower alkyl, lower alkoxy or tri-halomethyl;
[0034] Y is —O—;
[0035] n is an integer from 0 to 3;
[0036] R 4 is selected from the group consisting of hydrogen, heterocyclyl, oxo-substituted heterocyclyl, lower alkyl-substituted heterocyclyl, di(lower alkyl)amino, N-lower alkyl-N-aralkyl-amino and di(lower alkyl)amino alkoxy alkyl;
[0037] R 5 is selected from the group consisting of hydrogen and lower alkyl;
[0038] and the pharmaceutically acceptable salts, esters and pro-drug forms thereof.
[0039] In a preferred embodiment are compounds of the general formula (I) wherein:
[0040] R 1 is selected from the group consisting of hydrogen, phenyl (C 1 -C 6 ) alkyl-, naphthyl(C 1-6 )alkyl and heterocyclyl (C 1 -C 6 )alkyl- where the heterocyclyl group is selected from pyridyl and where the phenyl, naphthyl or heterocyclyl moiety is optionally substituted with one to three substituents selected from halogen, lower alkyl, lower alkoxy, tri-halomethyl, hydroxy and nitro;
[0041] R 2 is selected from the group consisting of (C 1 -C 6 )branched or unbranched alkyl, phenyl, phenyl(C 1 -C 6 )alkyl-, tri-halomethyl, phenylamino-, biphenyl, diphenyl(C 1 -C 6 )alkyl-, C 5-8 cycloalkyl, C 5 - 8 cycloalkyl-alkyl,heterocyclyl and heterocyclyl(C 1 -C 6 )alkyl- wherein the heterocyclyl moiety is selected from naphthyl, furyl, pyridyl, pyrrolidinyl and thienyl and wherein the phenyl or heterocyclyl group may be substituted with one to four substitutuents selected from halogen, lower alkoxy, nitro, carboxy, carboxy(C 1-4 )alkyl, hydroxy, phenyl, diphenylmethyl, trihalomethyl and trihaloalkylacetyl;
[0042] X 1 , X 2 , X 3 and X 4 are independently absent or selected from the group consisting of CO and SO 2 ; such that at least one of X 1 or X 2 and at least one of X 3 or X 4 is CO or SO 2 ;
[0043] A is selected from the group consisting of lower alkyl, loweralkyl-cycloalkyl, cycloalkyl-loweralkyl, -cycloalkyl, -cycloalkenyl-, cycloalkenyl-loweralkyl- and -phenyl-loweralkyl- and -benzyl-loweralkyl, provided that A is not −1,3-cyclopentyl-1-ene-alkyl;
[0044] R 3 is selected from the group consisting of hydrogen, phenyl, benzyl and phenylamino-; where the phenyl or benzyl moieties may be substituted with one to three substituents selected from halogen, lower alkyl, lower alkoxy and trihalomethyl;
[0045] Y is —O—;
[0046] n is an integer from 0 to 3;
[0047] R 4 is selected from the group consisting of hydrogen, heterocyclyl, oxo substituted heterocyclyl, lower alkyl-substituted heterocyclyl, di(loweralkyl) amino, N-lower alkyl-N-aralkyl-amino and a moiety of the formula:
[0048] where p and t are integers from 1-6;
[0049] R 5 is selected from hydrogen and lower alkyl;
[0050] and the pharmaceutically acceptable salts esters and pro-drug forms thereof.
[0051] In a more preferred embodiment of the present invention are compounds of the general formula (I) wherein
[0052] R 1 is selected from the group consisting of hydrogen, benzyl, 2-(phenyl)ethyl, 4-methylbenzyl, 3-methoxybenzyl, 3-nitrobenzyl, 3-chlorobenzyl, 3-fluorobenzyl, 4-chlorobenzyl, 2,3-dichlorobenzyl, 3,4-dichlorobenzyl, 3,5-dichlorobenzyl, 3,4-difluorobenzyl, 3-trifluoromethylbenzyl, 1-naphthyl-methyl, 2-pyridyl-methyl and 4-(1-hydroxy)pyridyl;
[0053] R 2 is selected from the group consisting of methyl, ethyl, t-butyl, 2,2-dimethylpropyl, benzyl, 2-(phenyl)ethyl, 3-(phenyl)propyl, 1-(phenyl)propyl, 3-carboxy-n-propyl, 3-carboxy-3-methyl-n-butyl, 2,2-dimethyl-3-carboxy-n-propyl, trichloromethyl, trifluoromethyl, 2-naphthyl, phenylamino, 3-methoxyphenyl, 3-hydroxyphenyl, 4-fluorobenzyl, 3-carboxybenzyl, 3-methoxybenzyl, 4-methoxybenzyl, 3,4-dimethoxybenzyl, 2-(4-methoxyphenyl)ethyl, 4-fluorophenyl, 2-(4-chlorophenyl)ethyl, 3-nitrophenyl, 3,5-di(trifluoromethyl)phenyl, 3,3,3-trifluoropropan-2-oyl, diphenylmethyl, 4-biphenyl, 3-carboxymethyl-1,2,2-trimethyl-cyclopentyl, cyclopentylethyl, (1-carboxymethyl-cyclopentyl)-methyl, 2-furyl, 2-pyridyl-(2-ethyl), 1-pyrrolidinyl-(2-ethyl), 2-theinylmethyl and 2-thienylethyl;
[0054] X 1 , X 2 , X 3 and X 4 are independently absent or selected from the group consisting of CO and SO 2 ; such that one of X 1 or X 2 and one of X 3 or X 4 is CO or SO 2 ;
[0055] A is selected from the group consisting of 1,2-ethyl, 1,3-propyl, 1,4-butyl, 2-methyl-1,3-propyl, 1,1,-dimethyl-(1,3-propyl), 2-cyclopentyl-1,3-n-propyl, 1S,3R-cyclopentyl-methyl, 1,2-cyclopent-1-enyl, 1,4-cyclopentyl-2-ene-methyl, methyl-1,3-cyclohexyl, 1,2-cyclohexyl-methyl-, 1,3-cyclohexyl-methyl-, 1S,3R-cyclohexyl-methyl-, 1R,3S-cyclohexyl-methyl, 1,4-cyclohexyl-methyl-, 1,2-cyclohex-4-enyl, 1,3-phenyl-methyl and 1-benzyl-methyl-;
[0056] R 3 is selected from the group consisting of hydrogen, phenylamino, 4-methylphenyl, 4-fluorophenyl, 2-fluorobenzyl, 3-fluorobenzyl, 4-fluorobenzyl, 4-chlorobenzyl, 4-methoxybenzyl and 4-trifluoromethylbenzyl;
[0057] Y is selected from the group consisting of −3-O— and −4-O—;
[0058] n is an integer selected from 0, 2 or 3;
[0059] R 4 is selected from the group consisting of hydrogen, 4-morpholinyl, 1-pyrrolidinyl, 2-oxo-pyrrolidin-1-yl, 2-(1-methylpyrrolidinyl), 1-piperazinyl, 1-piperidinyl, di(methyl)aminoethyloxyethyl, N-methyl-N-benzyl-amino, di(methyl)amino and diethylamino;
[0060] R 5 is selected from the group consisting of hydrogen, 2-methyl and 6-methyl;
[0061] and the pharmaceutically acceptable salts, esters and pro-drug forms thereof.
[0062] In another preferred embodiment of the present invention are compounds of the formula (I) wherein R 1 , R 2 and X 1 are taken together (with the amine nitrogen) to form an optionally substituted, monocyclic or fused bicyclic or tricyclic secondary amine ring structure selected from the group consisting of 1-phenyl-1,2,3,4-tetrahydroisoquinolinyl, 4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl, 2-[1-benzyl-6-methoxy-1,2,3,4-tetrahydro]naphthyl, isoindole-1,3-dione, 5-t-butyl-isoindole-1,3-dione, 5-fluoro-isoindole-1,3-dione, 5-methyl-isoindole-1,3-dione, 5,6-dichloro-isoindole-1,3-dione, 4,7-dichloro-isoindole-1,3-dione, 5-bromo-isoindole-1,3-dione, 5-acetyloxy-isoindole-1,3-dione, benzo[e]isoindole-1,3-dione, 8-fluorobenzo[e]isoindole-1,3-dione, 4,4-dimethyl-piperidine-2,6-dione, 3-aza-bicyclo[3.1.0]hexane-2,6-dione and 8-aza-spiro[4.5]decane-7,9-dione; and the pharmaceutically acceptable salts, esters and pro-drug forms thereof.
[0063] In a particularly preferred embodiment R 1 , R 2 and X 1 are taken together (with the amine nitrogen) to form 1-phenyl-1,2,3,4-tetrahydroisquinolinyl, X 2 is C(O), A is 1,3-propyl, X 3 is C(O), R 3 is 4-fluorobenzyl, Y is 3-O—, n is 2 and R 4 is 4-morpholinyl.
[0064] In another preferred embodiment R 1 , R 2 and X 1 are taken together (with the amine nitrogen) to form 4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl, X 2 is C(O), A is 1,3-n-propyl, X 3 is absent, R 3 is 4-fluorophenyl, X 4 is C(O), Y is 3-O—, n is 2 and R 4 is 4-morpholinyl.
[0065] In still another preferred embodiment, R 1 , R 2 and X 1 are taken together (with the amine nitrogen) to form 2 -[1-benzyl-6-methoxy-1,2,3,4-tetrahydro]-naphthyl, X 2 is C(O), A is 1,3-n-propyl, X 3 is absent, R 3 is 4-fluorophenyl, X 4 is C(O), Y is 3-O—, n is 2 and R 4 is 4-morpholinyl.
[0066] In a class of the invention are compounds of the formula (I) wherein
[0067] R 1 is selected from the group consisting of benzyl, 2-(phenyl)ethyl, 3-nitrobenzyl, 3-chlorobenzyl, 3,4-dichlorobenzyl, 3,4-difluorobenzyl, 3,5-dichlorobenzyl, 3-trifluoromethylbenzyl and 2-pyridyl-methyl;
[0068] R 2 is selected from the group consisting of t-butyl, 2-(phenyl)ethyl, trichloromethyl, 3-carboxybenzyl, 3-methoxybenzyl, 2-(4-methoxyphenyl)ethyl, 2-(4-chlorophenyl)ethyl, diphenylmethyl, 2-(2-pyridyl)ethyl, 2-(1-pyrrolidinyl)ethyl and 2-(2-thienyl)ethyl;
[0069] X 1 , X 2 , X 3 and X 4 are independently absent or CO; such that one of X 1 or X 2 and one of X 3 or X 4 is CO;
[0070] A is selected from the group consisting of 1,2-ethyl, 1,3-propyl, 2-methyl-1,3-propyl, 1,1,-dimethyl-(1,3-propyl), 2-cyclopentyl-1,3-n-propyl, 1S,3R-cyclopentyl-methyl, 1,3-cyclohexyl-methyl, 1S,3R-cyclohexyl-methyl- and 1R,3S-cyclohexyl-methyl-;
[0071] R 3 is selected from the group consisting of phenylamino, 4-fluorophenyl, 3-fluorobenzyl, 2-fluorobenzyl, 4-fluorobenzyl, 4-chlorobenzyl, 4-methoxybenzyl and 4-trifluoromethylbenzyl;
[0072] Y is selected from the group consisting of −3-O— and −4-O—;
[0073] n is an integer selected from 2 or 3;
[0074] R 4 is selected from the group consisting of hydrogen, 4-morpholinyl, 1-pyrrolidinyl, 1-piperazinyl, 1-piperidinyl, di(methyl)amino and di(ethyl)amino;
[0075] R 5 is selected from the group consisting of hydrogen, 2-methyl and 6-methyl;
[0076] and the pharmaceutically acceptable salts, esters and pro-drug forms thereof.
[0077] In another class of the invention are compounds of the formula (I) wherein
[0078] R 1 is selected from the group consisting of benzyl, 2-(phenyl)ethyl, 3-nitrobenzyl, 3-chlorobenzyl, 3,4-dichlorobenzyl, 3,4-difluorobenzyl, 3,5-dichlorobenzyl and 3-trifluoromethylbenzyl;
[0079] R 2 is selected from the group consisting of t-butyl, 2-(phenyl)ethyl, trichloromethyl, 3-carboxybenzyl, 3-methoxybenzyl, 2-(2-pyridyl)ethyl and 2-(2-thienyl)ethyl;
[0080] X 1 , X 2 , X 3 and X 4 are independently absent or CO; such that one of X 1 or X 2 and one of X 3 or X 4 is CO;
[0081] A is selected from the group consisting of 1,3-propyl, 1S,3R-cyclopentyl-methyl, 1,3-cyclohexyl-methyl-, 1S,3R-cyclohexyl-methyl- and 1R,3S-cyclohexyl-methyl-;
[0082] R 3 is selected from the group consisting of phenylamino, 4-fluorophenyl, 3-fluorobenzyl and 4-fluorobenzyl;
[0083] Y is −3-O—;
[0084] n is 2;
[0085] R 4 is selected from the group consisting of hydrogen, 4-morpholinyl, 1-pyrrolidinyl, 1-piperidinyl and di(methyl)amino;
[0086] R 5 is selected from the group consisting of hydrogen, 2-methyl and 6-methyl;
[0087] and the pharmaceutically acceptable salts, esters and pro-drug forms thereof.
[0088] Particularly preferred are compounds of the formula (I) wherein
[0089] R 1 is selected from the group consisting of benzyl, 3-nitrobenzyl, 3-chlorobenzyl, 3,4-dichlorobenzyl, 3,4-difluorobenzyl and 3-trifluoromethylbenzyl;
[0090] R 2 is selected from the group consisting of t-butyl, 2-(phenyl)ethyl, trichloromethyl, 2-(2-pyridyl)ethyl and 2-(2-thienyl)ethyl;
[0091] X 1 , X 2 , X 3 and X 4 are independently absent or CO; such that one of X 1 or X 2 and one of X 3 or X 4 is CO;
[0092] A is selected from the group consisting of 1,3-propyl, 1S,3R-cyclopentyl-methyl, 1,3-cyclohexyl-methyl-, 1S,3R-cyclohexyl-methyl- and 1R,3S-cyclohexyl-methyl-;
[0093] R 3 is selected from the group consisting of phenylamino, 4-fluorophenyl, 3-fluorobenzyl and 4-fluorobenzyl;
[0094] Y is -3-O—;
[0095] n is 2;
[0096] R 4 is selected from the group consisting of hydrogen, 4-morpholinyl, 1-pyrrolidinyl and 1-piperidinyl;
[0097] R 5 is selected from the group consisting of hydrogen and 2-methyl;
[0098] and the pharmaceutically acceptable salts, esters and pro-drug forms thereof.
[0099] In still another particularly preferred embodiment of the present invention are compounds of the formula (I) wherein R 1 is 3-chlorobenzyl, R 2 is trichloromethyl, X 1 is CO, X 2 is absent, X 3 is absent, X 4 is CO, A is 1S,3R-cyclohexyl-methyl-, R 3 is 4-fluorophenyl, Y is −3-O—, n is 2,R 4 is 1-piperidinyl, R 5 is hydrogen and the pharmaceutically acceptable salts, esters and pro-drug forms thereof.
[0100] In still another particularly preferred embodiment of the present invention are compounds of the formula (I) wherein R 1 is 3-chlorobenzyl, R 2 is trichloromethyl, X 1 is CO, X 2 is absent, X 3 is absent, X 4 is CO, A is 1R,3S-cyclohexyl-methyl-, R 3 is 4-fluorophenyl, Y is −3-O—, n is 2,R 4 is 1-piperidinyl, R 5 is hydrogen and the pharmaceutically acceptable salts, esters and pro-drug forms thereof.
[0101] Listed in Tables 1-16 are specific compounds of the present invention.
TABLE 1 ID # R 1 R 2 R 3 128 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 163 3-chlorobenzyl 2-(phenyl)ethyl 4-fluorobenzyl 164 benzyl 2-(phenyl)ethyl 3-fluorobenzyl 165 benzyl 2-(phenyl)ethyl 2-fluorobenzyl 166 benzyl 2-(phenyl)ethyl 4-methoxybenzyl 167 benzyl 2-(phenyl)ethyl 4-trifluoromethylbenzyl 168 benzyl 2-(phenyl)ethyl 4-chlorobenzyl
[0102] [0102] TABLE 2 ID R 1 R 2 R 3 Y n R 4 R 5 129 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 4-morpholinyl H 159 benzyl 3-(phenyl)propyl 4-fluorobenzyl 3-O 2 4-morpholinyl H 162 3-chlorobenzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 4-morpholinyl H 169 benzyl 2-(phenyl)ethyl 3-fluorobenzyl 3-O 2 4-morpholinyl H 170 benzyl 2-(phenyl)ethyl 2-fluorobenzyl 3-O 2 4-morpholinyl H 171 benzyl 2-(phenyl)ethyl 4-methoxybenzyl 3-O 2 4-morpholinyl H 172 benzyl 2-(phenyl)ethyl 4-trifluoromethylbenzyl 3-O 2 4-morpholinyl H 173 benzyl 2-(phenyl)ethyl 4-chlorobenzyl 3-O 2 4-morpholinyl H 175 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O— 0 H H 176 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 2-oxo-pyrrolidin-1-yl H 177 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 dimethylamino H ethyloxyethyl 178 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 diethylamino H 179 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 1-piperazinyl H 180 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 1-pyrrolidinyl H 181 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 dimethylamino H 182 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 1-piperidinyl H 187 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 3 dimethylamino H 188 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 3 1-piperidinyl H 191 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 4-O 2 1-pyrrolidinyl H 192 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 4-O 2 4-morpholinyl H 193 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 4-O 3 1-piperidinyl H 194 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 4-O 2 dimethylamino H 195 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 4-O 2 diethylamino H 196 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 1-pyrrolidinyl 2-methyl 197 3-nitrobenzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 1-pyrrolidinyl H 198 3-chlorobenzyl 3-methoxybenzyl 4-fluorobenzyl 3-O 2 1-pyrrolidinyl H 199 3,5-dichlorobenzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 1-pyrrolidinyl H 200 3-trifluoromethylbenzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 1-pyrrolidinyl H 201 3-chlorobenzyl 2-(2-pyridyl)ethyl 4-fluorobenzyl 3-O 2 1-pyrrolidinyl H 202 3-chlorobenzyl 2-(4-chlorophenyl)ethyl 4-fluorobenzyl 3-O 2 1-pyrrolidinyl H 203 3-chlorobenzyl 2-(1-pyrrolidinyl)ethyl 4-fluorobenzyl 3-O 2 1-pyrrolidinyl H 204 3-chlorobenzyl 2-(2-thienyl)ethyl 4-fluorobenzyl 3-O 2 1-pyrrolidinyl H 205 3-nitrobenzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 4-morpholinyl H 206 3-chlorobenzyl 3-methoxybenzyl 4-fluorobenzyl 3-O 2 4-morpholinyl H 207 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 1-pyrrolidinyl 6-methyl 215 2-(phenyl)ethyl 3-carboxybenzyl 4-fluorobenzyl 3-O 2 1-pyrrolidinyl 2-methyl 234 benzyl 2-(phenyl)ethyl 4-fluorobenzyl 3-O 2 4-morpholinyl 2-methyl
[0103] [0103] TABLE 3 ID R 1 R 2 A R 3 154 ben- 2-(phe- 2-cyclopentenyl-1,3-n-propyl 4-fluorobenzyl zyl nyl)ethyl 155 ben- 2-(phe- cis-1,2-cyclohex-4-enyl 4-fluorobenzyl zyl nyl)ethyl 156 ben- 2-(phe- 1,2-cylopentenyl H zyl nyl)ethyl 160 ben- 2-(phe- 1,3-n-butyl 4-fluorobenzyl zyl nyl)ethyl 189 ben- 2-(phe- 2-methyl-(1,3-propyl) 4-fluorobenzyl zyl nyl)ethyl 190 ben- 2-(phe- 1,1-dimethyl-(1,3-propyl) 4-fluorobenzyl zyl nyl)ethyl
[0104] [0104] TABLE 4 ID R 1 R 2 X 4 R 3 5 benzyl 2-(phenyl)ethyl CO phenylamino 6 benzyl 2-(phenyl)ethyl CO 4-methylphenyl 7 benzyl 2-(phenyl)ethyl CO 4-fluorophenyl 12 benzyl ethyl SO 2 4-methylphenyl 13 benzyl ethyl CO 4-methylphenyl 14 benzyl ethyl CO 4-fluorophenyl 19 benzyl methyl CO phenylamino 20 benzyl methyl SO 2 4-methylphenyl 21 benzyl methyl CO 4-methylphenyl 22 benzyl methyl CO 4-fluorophenyl 26 benzyl benzyl CO phenylamino 27 benzyl benzyl SO 2 4-methylphenyl 28 benzyl benzyl CO 4-methylphenyl 29 benzyl benzyl CO 4-fluorophenyl 34 4-methylbenzyl ethyl CO phenylamino 35 4-methylbenzyl ethyl SO 2 4-methylphenyl 36 4-methylbenzyl ethyl CO 4-methylphenyl 37 4-methylbenzyl ethyl CO 4-fluorophenyl
[0105] [0105] TABLE 5 ID R 1 R 2 X 4 R 3 1 benzyl 2-(phenyl)ethyl CO phenylamino 2 benzyl 2-(phenyl)ethyl SO 2 4-methylphenyl 3 benzyl 2-(phenyl)ethyl CO 4-methylphenyl 4 benzyl 2-(phenyl)ethyl CO 4-fluorophenyl 8 benzyl ethyl CO phenylamino 9 benzyl ethyl SO 2 4-methylphenyl 10 benzyl ethyl CO 4-methylphenyl 11 benzyl ethyl CO 4-fluorophenyl 15 benzyl methyl CO phenylamino 16 benzyl methyl SO 2 4-methylphenyl 17 benzyl methyl CO 4-methylphenyl 18 benzyl methyl CO 4-fluorophenyl 23 benzyl benzyl CO phenylamino 24 benzyl benzyl SO 2 4-methylphenyl 25 benzyl benzyl CO 4-methylphenyl 30 4-methyl- ethyl CO phenylamino benzyl 31 4-methyl- ethyl SO 2 4-methylphenyl benzyl 32 4-methyl- ethyl CO 4-methylphenyl benzyl 33 4-methyl- ethyl CO 4-fluorophenyl benzyl 143 H diphenylmethyl CO 4-fluorophenyl 144 benzyl 3-(phenyl)propyl CO 4-fluorophenyl 145 benzyl 2,2-dimethylpropyl CO 4-fluorophenyl 146 benzyl 2-(4-methoxyphenyl)ethyl CO 4-fluorophenyl 147 3-chloro- 2-(4-methoxyphenyl)ethyl CO 4-fluorophenyl benzyl
[0106] [0106] TABLE 6 ID R 1 R 2 Stereo # R 3 R 4 232 3-chlorobenzyl t-butyl cis racemate 4-fluorophenyl N-methyl-N-benzyl-amino 233 3-chlorobenzyl t-butyl cis racemate 4-fluorophenyl di(ethyl)amino 235 3-chlorobenzyl t-butyl cis racemate 4-fluorophenyl 2-(1-methyl)pyrrolidinyl 236 3-chlorobenzyl trichloromethyl cis racemate 4-fluorophenyl 2-(1-methyl)pyrrolidinyl 237 3-chlorobenzyl t-butyl cis racemate 4-fluorophenyl 1-piperidinyl 238 3-chlorobenzyl trichloromethyl cis racemate 4-fluorophenyl 1-piperidinyl 239 a 3-chlorobenzyl trichloromethyl 1S, 3R 4-fluorophenyl 1-piperidinyl 240 b 3-chlorobenzyl trichloromethyl 1R, 3S 4-fluorophenyl 1-piperidinyl 264 hydrogen 3-carboxy-n-propyl cis racemate 4-fluorophenyl 1-piperidinyl 265 hydrogen 3-carboxy-1,2,2-trimethylcyclopentyl cis racemate 4-fluorophenyl 1-piperidinyl 266 hydrogen 3-methyl-3-carboxy-n-butyl cis racemate 4-fluorophenyl 1-piperidinyl 267 hydrogen (1-carboxymethyl-cyclopentyl)-methyl cis racemate 4-fluorophenyl 1-piperidinyl 268 hydrogen 3-carboxy-2,2-dimethyl-n-propyl cis racemate 4-fluorophenyl 1-piperidinyl
[0107] [0107] TABLE 7 ID R 1 X 1 R 2 R 3 40 benzyl CO phenylamino phenylamino 41 benzyl CO 3-methoxyphenyl phenylamino 42 benzyl CO t-butyl phenylamino 43 benzyl CO 2-(phenyl)ethyl phenylamino 44 benzyl CO 2-naphthyl phenylamino 45 benzyl CO 3-nitrophenyl phenylamino 46 benzyl CO diphenylmethyl phenylamino 47 3-chlorobenzyl CO trichloromethyl phenylamino 48 benzyl CO 2-furyl phenylamino 49 3-chlorobenzyl CO 3,5-di-tri- phenylamino fluoromethylphenyl 50 3-chlorobenzyl CO 4-biphenyl phenylamino 51 3-chlorobenzyl CO 3-methoxyphenyl phenylamino 52 3-chlorobenzyl CO t-butyl phenylamino 53 3-chlorobenzyl CO 2-(phenyl)ethyl phenylamino 54 3-chlorobenzyl CO 2-naphthyl phenylamino 55 3-chlorobenzyl CO 3-nitrophenyl phenylamino 56 3-chlorobenzyl CO diphenyl methyl phenylamino 57 benzyl SO 2 2-naphthyl phenylamino 58 3-fluorobenzyl CO trichloromethyl phenylamino 59 3,4-dichloro- CO trichloromethyl phenylamino benzyl 60 3,5-dichloro- CO trichloromethyl phenylamino benzyl 61 3-methoxybenzyl CO trichloromethyl phenylamino 62 3-trifluoro- CO trichloromethyl phenylamino methylbenzyl 63 4-chlorobenzyl CO trichloromethyl phenylamino 64 1-naphthyl- CO trichloromethyl phenylamino methyl 65 3-nitrobenzyl CO trichloromethyl phenylamino 66 2,3-dichloro- CO trichloromethyl phenylamino benzyl 67 benzyl CO trichloromethyl phenylamino 68 2-pyridyl-methyl CO trichloromethyl phenylamino 69 H CO phenynamino phenylamino 70 H CO 2-furyl phenylamino 71 H SO 2 2-naphthyl phenylamino 72 H CO trichioromethyl phenylamino 73 H CO trifluoromethyl phenylamino 74 H CO 3,5-di-trifluoro- phenylamino methylphenyl 75 H CO 4-biphenyl phenylamino 76 H CO 3-methoxyphenyl phenylamino 77 H CO t-butyl phenylamino 78 H CO 2-(phenyl)ethyl phenylamino 79 H CO 2-naphthyl phenylamino 80 H CO 3-nitrophenyl phenylamino 81 H CO diphenylmethyl phenylamino 82 benzyl CO 3,5-di(trifluoro- phenylamino methyl)phenyl 83 benzyl CO 4-biphenyl phenylamino 86 3-chlorobenzyl CO 3-hydroxyphenyl phenylamino 90 2-pyridyl-methyl CO trichloromethyl 4-fluorophenyl 91 H CO trichloromethyl 4-fluorophenyl 92 2,3-dichloro- CO trichloromethyl 4-fluorophenyl benzyl 93 3-nitrobenzyl CO trichloromethyl 4-fluorophenyl 94 1-naphthyl- CO trichloromethyl 4-fluorophenyl methyl 95 4-chlorobenzyl CO trichloromethyl 4-fluorophenyl 96 3-trifluoro- CO trichloromethyl 4-fluorophenyl methylbenzyl 97 3-methoxybenzyl CO trichloromethyl 4-fluorophenyl 98 3,5-dichloro- CO trichloromethyl 4-fluorophenyl benzyl 99 3,4-dichloro- CO trichloromethyl 4-fluorophenyl benzyl 100 3-fluorobenzyl CO trichloromethyl 4-fluorophenyl 101 3-chlorobenzyl CO diphenylmethyl 4-fluorophenyl 102 3-chlorobenzyl CO 3-nitrophenyl 4-fluorophenyl 103 3-chlorobenzyl CO 2-naphthyl 4-fluorophenyl 104 3-chlorobenzyl CO 2-(phenyl)ethyl 4-fluorophenyl 105 3-chlorobenzyl CO t-butyl 4-fluorophenyl 106 3-chlorobenzyl CO 3-methoxyphenyl 4-fluorophenyl 107 3-chlorobenzyl CO 3,5-di-trifluoro- 4-fluorophenyl methylphenyl 108 3-chlorobenzyl CO trifluoromethyl 4-fluorophenyl 109 3-chlorobenzyl CO 4-biphenyl 4-fluorophenyl 110 3-chlorobenzyl CO 3,3,3-tri- 4-fluorophenyl fluoropropan-2-onyl 111 3-chlorobenzyl CO trichloromethyl 4-fluorophenyl 112 benzyl CO diphenylmethyl 4-fluorophenyl 113 benzyl CO 3-nitrophenyl 4-fluorophenyl 114 benzyl CO 2-naphthyl 4-fluorophenyl 115 benzyl CO 2-(phenyl)ethyl 4-fluorophenyl 116 benzyl CO t-butyl 4-fluorophenyl 117 benzyl CO 3-methoxyphenyl 4-fluorophenyl 118 benzyl CO 4-biphenyl 4-fluorophenyl 119 benzyl CO 3,5-ditrifluoro- 4-fluorophenyl methylphenyl 120 benzyl CO trifluoromethyl 4-fluorophenyl 121 benzyl CO 3,3,3-trifluoro- 4-fluorophenyl propan-2-onyl 122 benzyl CO trichloromethyl 4-fluorophenyl 123 benzyl SO 2 2-naphthyl 4-fluorophenyl 124 benzyl CO 2-furyl 4-fluorophenyl 125 benzyl CO phenylamino 4-fluorophenyl 241 3-chlorobenzyl CO 3-methoxybenzyl 4-fluorophenyl 242 3-chlorobenzyl CO 2-cyclopentylethyl 4-fluorophenyl 243 3-chlorobenzyl CO 4-methoxybenzyl 4-fluorophenyl 244 3-chlorobenzyl CO Benzyl 4-fluorophenyl 245 3-chlorobenzyl CO 3,4-dimethoxybenzyl 4-fluorophenyl 246 3-chlorobenzyl CO t-butylmethyl 4-fluorophenyl 247 3-chlorobenzyl CO 1(1-phenyl)propyl 4-fluorophenyl 248 3-chlorobenzyl CO 2-thienylmethyl 4-fluorophenyl 249 3-chlorobenzyl CO 4-fluorobenzyl 4-fluorophenyl
[0108] [0108] TABLE 8 ID R 1 R 2 R 3 158 H trichloromethyl 4-fluorophenyl 161 3-chlorobenzyl t-butyl 4-fluorophenyl 157 benzyl trifluoromethyl 4-fluorophenyl
[0109] [0109] TABLE 9 ID R 1 R 2 Stereo # R 3 R 5 208 3-nitrobenzyl tri- 1S, 3R 4-fluorophenyl CH 3 chloromethyl 209 3-chlorobenzyl tri- 1S, 3R 4-fluorophenyl CH 3 chloromethyl 210 benzyl tri- 1S, 3R 4-fluorophenyl CH 3 chloromethyl 223 3-chlorobenzyl tri- cis phenylamino H chloromethyl racemate 224 benzyl tri- cis phenylamino H chloromethyl racemate 225 benzyl t-butyl cis phenylamino H racemate 226 3-chlorobenzyl t-butyl cis 4-fluorophenyl H racemate 227 3,4-dichloro- t-butyl cis 4-fluorophenyl H benzyl racemate 228 3,4-difluoro- t-butyl cis 4-fluorophenyl H benzyl racemate 229 benzyl t-butyl 1S, 3R 4-fluorophenyl H 230 benzyl t-butyl 1R, 3S 4-fluorophenyl H 211 3-nitrobenzyl tri- cis 4-fluorophenyl H chloromethyl racemate 212 3-chlorobenzyl tri- cis 4-fluorophenyl H chloromethyl racemate 213 benzyl tri- cis 4-fluorophenyl H chloromethyl racemate 214 benzyl t-butyl cis 4-fluorophenyl H racemate
[0110] [0110] TABLE 10 Cyclohexyl Relative Conformation is CIS ID R 1 R 2 R 3 174 2-pyridylmethyl trichloromethyl 4-fluorophenyl 183 benzyl benzyl phenylamino 184 3-chlorobenzyl 3-methoxyphenyl phenylamino 185 3-chlorobenzyl 2-furyl phenylamino 186 3-nitrobenzyl 3-methoxyphenyl phenylamino
[0111] [0111] TABLE 11 ID R 1 R 2 Stereo R 3 216 benzyl t-butyl 1S, 3R 4-fluorophenyl 217 3-chlorobenzyl t-butyl 1S, 3R 4-fluorophenyl 218 benzyl trichloromethyl 1S, 3R 4-fluorophenyl 219 3-nitrobenzyl trichloromethyl 1S, 3R 4-fluorophenyl 220 3,4-difluorobenzyl t-butyl 1S, 3R 4-fluorophenyl 231 benzyl trichloromethyl 1R, 3S 4-fluorophenyl
[0112] [0112] TABLE 12 ID R 1 X 1 R 2 130 H CO 2-(phenyl)ethyl 131 H CO trichloromethyl 132 H CO 4-biphenyl 133 H CO diphenylmethyl 134 H CO 3-methoxybenzyl 135 H SO 2 4-biphenyl 151 benzyl CO trichloromethyl 152 benzyl CO 2-(phenyl)ethyl
[0113] [0113] TABLE 13 ID R 1 R 2 136 benzyl 2-(phenyl)ethyl 137 H diphenylmethyl 138 H 2-(phenyl)ethyl 139 benzyl 3-(phenyl)propyl 140 benzyl 2,2-dimethylpropyl 141 3-chlorobenzyl 2,2-dimethylpropyl
[0114] [0114] TABLE 14 R 1 , R 2 and X 1 Taken ID Together (with the amine nitrogen) A X 3 X 4 R 3 142 1-phenyl-1,2,3,4- 1,3-phenyl- absent CO 4-fluoro tetrahydroisoquinolin-2-yl methyl phenyl 148 1-phenyl-1,2,3,4- 1,3-n-propyl absent CO 4-fluoro tetrahydroisoquinolin-2-yl phenyl 149 4-[(4- 1,3-n-propyl absent CO 4-fluoro chlorophenyl)phenylmethyl]- phenyl piperazin-1-yl 150 2-[1-benzyl-6-methoxy- 1,3-n-propyl absent CO 4-fluoro 1,2,3,4-tetrahydro]-naphthyl phenyl 153 1-phenyl-1,2,3,4- 1,3-n-propyl CO absent 4-fluoro tetrahydroisoquinolinyl benzyl
[0115] [0115] TABLE 15 ID R 1 R 2 A R 3 R 4 39 3-chloro trichloro methyl-1,3- phenyl 4-morpholinyl benzyl methyl cyclopentyl amino 221 benzyl t-butyl 1,4-cyclopentyl- 4-fluoro 1-pyrrolidinyl 2-ene-methyl phenyl
[0116] [0116] TABLE 16 R 1 , R 2 and X 1 Taken Together ID (with the amine nitrogen) 250 5-t-butyl-isoindole-1,3-dione 251 5-fluoro-isoindole-1,3-dione 252 benzo[e]isoindole-1,3-dione 253 5-methyl-isoindole-1,3-dione 254 8-aza-spiro[4.5]decane-7,9-dione 255 5,6-dichloro-isoindole-1,3-dione 256 5-methyl-isoindole-1,3-dione 257 isoindole-1,3-dione 258 4,4-dimethyl-piperidine-2,6-dione 259 5-bromo-isoindole-1,3-dione 260 5-acetyloxy-isoindole-1,3-dione 261 8-fluoro-benzo[e]isoindole-1,3-dione 262 3-aza-bicyclo[3.1.0]hexane-2,4-dione 263 4,7-dichloro-isoindole-1,3-dione
[0117] Particularly preferred intermediates in the preparation of compounds of formula (I) are listed in Table 17 below.
TABLE 17 ID # R 1 R 2 R 3 R 4 84 benzyl H phenylamino 4-morpholino 85 3-chlorobenzyl H phenylamino 4-morpholino 87 3,5-dichlorobenzyl H phenylamino 4-morpholino 88 1-naphthylmethyl H phenylamino 4-morpholino 89 4-(1-hydroxy)-pyridyl H phenylamino 4-morpholino 222 benzyl benzyl 4-fluorophenyl 1-pyrrolidinyl
[0118] Illustrative of the invention is a pharmaceutical composition comprising a pharmaceutically acceptable carrier and any of the compounds described above. Illustrating the invention is a pharmaceutical composition made by mixing any of the compounds described above and a pharmaceutically acceptable carrier. A further illustration of the invention is a process for making a pharmaceutical composition comprising mixing any of the compounds described above and a pharmaceutically acceptable carrier.
[0119] Included in the invention is the use of any of the compounds described above for the preparation of a medicament for treating a disorder mediated by the motilin receptor, in a subject in need thereof.
[0120] Also included in the invention is the use of any of the compounds described above for the preparation of a medicament for treating a condition selected from gastrointestinal reflux disorders, eating disorders leading to obesity and irritable bowel syndrome in a subject in need thereof.
[0121] Exemplifying the invention are methods of treating a disorder mediated by the motilin receptor, in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of any of the compounds or pharmaceutical compositions described above.
[0122] An example of the invention is a method for treating a condition selected from gastrointestinal reflux disorders, eating disorders leading to obesity and irritable bowel syndrome in a subject in need thereof, comprising administering to the subject an effective amount of any of the compounds or pharmaceutical compositions described above.
[0123] Another example of the invention is the use of any of the compounds described above in the preparation of a medicament for: (a) treating gastrointestinal reflux disorders, (b) treating irritable bowel syndrome, (c) treating eating disorders leading to obesity, in a subject in need thereof.
[0124] Listed below are definitions of various terms used to describe this invention. These definitions apply to the terms as they are used throughout this specification, unless otherwise limited in specific instances, either individually or as part of a larger group.
[0125] The term “halogen” or “halo” refers to fluorine, chlorine, bromine and iodine.
[0126] The term “alkyl”, unless otherwise specified, refers to straight or branched chain unsubstituted hydrocarbon groups of 1 to 20 carbon atoms, preferably 1 to 8 carbon atoms. The expression “lower alkyl” refers to straight or branched chain unsubstituted alkyl groups of 1 to 6 carbon atoms. For example, alkyl radicals include, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, 3-methylbutyl, 2-pentyl, 2-methylpropyl, 2-methylbutyl, 3,3-dimethylpropyl, neo-pentyl, n-hexyl, 2-hexyl and 2-methylpentyl. Similarly, the term “alkenyl”, unless otherwise specified, refers to straight or branched chain alkene groups of 2 to 10 carbon atoms. The term “lower alkenyl” refers to straight or branched chain alkene groups of 2 to 6 carbon atoms.
[0127] The term “substituted alkyl”, unless otherwise specified, refers to an alkyl group substituted by, for example, one to four substituents, such as, halo, trifluoromethyl, trifluoromethoxy, hydroxy, alkoxy, cycloalkyoxy, heterocyclyloxy, oxo, alkanoyl, aryloxy, alkanoyloxy, amino, alkylamino, arylamino, aralkylamino, cycloalkylamino, heterocycloamino, disubstituted amines in which the amino substituents are independently selected from alkyl, aryl or aralkyl, alkanoylamine, aroylamino, aralkanoylamino, substituted alkanoylamino, substituted arylamino, substituted aralkanoylamino, thiol, alkylthio, arylthio, aralkylthio, cycloalkylthio, heterocyclothio, alkylthiono, arylthiono, aralkylthiono, alkylsulfonyl, arylsulfonyl, aralkylsulfonyl, sulfonamido (e.g. SO 2 NH 2 ), substituted sulfonamido, nitro, cyano, carboxy, carbamyl (e.g. CONH 2 ) substituted carbamyl (e.g. CONH alkyl, CONH aryl, CONH aralkyl or cases where there are two substituents on the nitrogen selected from alkyl, aryl or aralkyl), alkoxycarbonyl, aryl, substituted aryl, guanidino and heterocyclos, such as indolyl, imidazolyl, furyl, thienyl, thiazolyl, pyrrolidyl, pyridyl, pyrimidyl and the like.
[0128] The term “cycloalkyl”, unless otherwise specified, refers to saturated unsubstituted cyclic hydrocarbon ring systems, preferably containing 1 to 3 rings and 3 to 8 carbon atoms per ring. For example, cycloalkyl radicals include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and the like. Similarly, the term “cycloalkenyl” refers to partially unsaturated, unsubstituted cyclic hydrocarbon groups of 3 to 20 carbon atoms, preferably 3 to 8 carbon atoms. Suitable examples of cycloalkenyl groups include cyclobutenyl, cyclopentenyl, cyclohexenyl, cyclooctyl, cyclodecyl, cyclododecyl, adamantyl, and the like.
[0129] The term “alkoxy”, unless otherwise specified, refers to oxygen ether radical of the above described straight or branched chain alkyl groups. The expression “lower alkoxy” refers to unsubstituted alkoxy groups of 1 to 6 carbon atoms. Suitable examples of alkoxy groups include methoxy, ethoxy, n-propoxy, sec-butoxy, t-butoxy, n-hexyloxy and the like.
[0130] The term “aryl”, unless otherwise specified, refers to monocyclic or bicyclic aromatic hydrocarbon groups having 6 to 12 carbon atoms in the ring portion, such as phenyl, naphthyl, biphenyl and diphenyl, each of which may be optionally substituted.
[0131] The term “aralkyl”, unless otherwise specified, refers to an aryl group bonded directly through an alkyl group, such as benzyl, 2-(phenyl)ethyl, 3-(phenyl)propyl, naphthyl-methyl and the like.
[0132] The term “substituted aryl” refers to an aryl group substituted by, for example, one to five substituents such as alkyl; substituted alkyl, halo, trifluoromethoxy, trifluoromethyl, hydroxy, alkoxy, cycloalkyloxy, heterocyclooxy, alkanoyl, alkanoyloxy, amino, alkylamino, aralkylamino, cycloalkylamino, heterocycloamino, dialkylamino, alkanoylamino, thiol, alkylthio, cycloalkylthio, heterocyclothio, ureido nitro, cyano, carboxy, carboxyalkyl, carbamyl, alkoxycarbonyl, alkylthiono, arylthiono, alkysulfonyl, sulfonamido, aryloxy and the like.
[0133] The term “diarylalkyl”, unless otherwise specified, refers to an alkyl group substituted with two independently selected aryl groups. Suitable examples include diphenylmethyl, 1,1-diphenylethyl, and the like.
[0134] The term “heteroatom” shall include oxygen, sulfur and nitrogen.
[0135] The terms “heterocyclyl”, “heterocyclic” and “heterocyclo”, unless otherwise specified, refer to a saturated, unsaturated, partially unsaturated, aromatic, partially aromatic or non-aromatic cyclic group. Such a group, for example, can be a 4 to 7 membered monocyclic or a 7 to 11 bicyclic ring system which contains at least one heteroatom in at least one carbon atom containing ring. Each ring of the heterocyclic group containing a heteroatom may have 1, 2, 3 or 4 heteroatoms selected from nitrogen atoms, oxygen atoms and sulfur atoms, where the nitrogen and sulfur heteroatoms may also optionally be oxidized and where the nitrogen heteroatoms may also optionally be quaternized. The heterocyclic group may be attached at any heteroatom or carbon atom.
[0136] Exemplary monocyclic heterocyclic groups include pyrrolidinyl, pyrrolyl, indolyl, pyrazolyl, oxetanyl, pyrazolinyl, imidazolyl, imidazolinyl, imidazolidinyl, oxazolyl, oxazolidinyl, isoxazolinyl, isoxazolyl, thiazolyl, thiadiazolyl, thiazolidinyl, isothiazolyl, isothiazolidinyl, furyl, tetrahydrofuryl, thienyl, oxadiazolyl, piperidinyl, piperazinyl, 2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolidinyl, 2-oxazepinyl, azepinyl, 4-piperidonyl, pyridyl, N-oxo-pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, tetrahydropryanyl, tetrahydrothiopyranyl, tetrahydrothiopyranyl sulfone, morpholinyl, thiomorpholinyl, thiomorpholinyl sulfoxide, thiomorpholinyl sulfone, 1,3-dioxolane, tetrahydro-1, 1-dioxothienyl, dioxanyl, isothiazolidinyl, thietanyl, thiiranyl, triazinyl, triazolyl, tetrazolyl and the like.
[0137] Exemplary bicyclic heterocyclic groups include benzothiazolyl, benzoxazolyl, benzothienyl, quinuclidinyl, quinolinyl, quinolinyl-N-oxide, tetrahydroisoquinolinyl, isoquinolinyl, benzimidazolyl, benzopyranyl, indolizinyl, benzofuryl, chromonyl, coumarinyl, cinnolinyl, quinoxalinyl, indazolyl, pyrrolopyridyl, furopyridinyl (such as furo[2,3-c]pyridinyl, furo[3,1-b]pyridinyl, or furo[2,3-b]pyridinyl), dihydroisoindolyl, dihydroquinazolinyl (such as 3,4-dihydro-4-oxo-quinazolinyl), benzisothiazolyl, benzisoxazolyl, benzodiazinyl, benzofurazanyl, benzothiopyranyl, benzotriazolyl, benzpyrazolyl, dihydrobenzofuryl, dihydrobenzothienyl, dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone, dihydrobenzopyranyl, indolinyl, isochromanyl, isoindolinyl, naphthyridinyl, phthalazinyl, piperonyl, purinyl, pyridopyridyl, quinazolinyl, tetrahydroquinolinyl, thienofuryl, thienopyridyl, thienothienyl, and the like.
[0138] The term “monocyclic or fused bicyclic or tricyclic secondary amine ring structure” shall mean any 4 to 8 monocyclic or 7 to 11 fused bicyclic or 13 to 14 tricyclic ring structure; wherein the ring structure is saturated, partially unsaturated or benzo-fuzed; wherein the ring structure contains at least one nitrogen atom through which the ring structure is bound directly to the other portions of the compound; and wherein the ring structure may optionally containing one to three additional heteroatoms selected from nitrogen, oxygen or sulfur.
[0139] Suitable examples include 1,2,3,4-tetrahydroisoquinolinyl, 1-piperazinyl, 1,2,3,4-tetrahydronaphthyl, isoindolyl, benzo[e]isoindolyl, 8-aza-spiro[4.5]decane, 3-aza-bicyclo[3.1.o]hexane, and the like.
[0140] The monocylic, bicyclic or tricyclic secondary amine ring structure may optionally be substituted with one to five substituents independently selected from alkyl, substituted alkyl, halo, trifluoromethoxy, trifluoromethyl, hydroxy, alkoxy, cycloalkyloxy, heterocyclooxy, alkanoyl, alkanoyloxy, amino, alkylamino, aralkylamino, cycloalkylamino, heterocycloamino, dialkylamino, alkanoylamino, thiol, alkylthio, cycloalkylthio, heterocyclothio, ureido nitro, cyano, oxo, carboxy, carboxyalkyl, carbamyl, alkoxycarbonyl, alkylthiono, arylthiono, alkysulfonyl, sulfonamido, aryloxy, aryl, aralkyl, heterocyclyl, and the like.
[0141] The term “tri-halomethyl” refers to trichloromethyl, trifluoromethyl, tribromomethyl and triiodomethyl.
[0142] Under standard nomenclature used throughout this disclosure, the terminal portion of the designated side chain is described first, followed by the adjacent functionality toward the point of attachment. Thus, for example, a “phenyl(alkyl)amido(alkyl)” substituent refers to a group of the formula
[0143] Where the compounds according to this invention have at least one chiral center, they may accordingly exist as enantiomers. Where the compounds possess two or more chiral centers, they may additionally exist as diastereomers. It is to be understood that all such isomers and mixtures thereof are encompassed within the scope of the present invention. Furthermore, some of the crystalline forms for the compounds may exist as polymorphs and as such are intended to be included in the present invention. In addition, some of the compounds may form solvates with water (i.e., hydrates) or common organic solvents, and such solvates are also intended to be encompassed within the scope of this invention.
[0144] As used herein, the term “cis racemate” indicates a mixture of four possible diastereomers, more particularly, two cis diastereomers and two trans diastereomers, with the two cis diastereomers present in a amount equal to greater than about 75%, preferably in an amount greater than about 90%, more preferably in an amount greater than about 95%.
[0145] When a particular group is “substituted” (e.g., aryl, heteroaryl, heterocyclyl), that group may have one or more substituents, preferably from one to five substituents, more preferably from one to three substituents, most preferably from one to two substituents, independently selected from the list of substituents. Where the group has a plurality of moieties, such as “alkylamino” or “heterocyclyl-alkyl” the substitution may be on any or all of the moieties independently, e.g. in the case of “alkylamino” the substitution may be on the alkyl or amino moiety, or both.
[0146] It is intended that the definition of any substituent or variable at a particular location in a molecule be independent of its definitions elsewhere in that molecule. It is understood that substituents and substitution patterns on the compounds of this invention can be selected by one of ordinary skill in the art to provide compounds that are chemically stable and that can be readily synthesized by techniques known in the art as well as those methods set forth herein.
[0147] Suitable protecting groups as referred to within this specification include the standard hydroxy and amino protecting groups, as applicable. The terms “hydroxy protecting group” and “amino protecting group” as used herein mean any of the known protecting groups used in the art of organic synthesis, for example as described in Protective Groups in Organic Synthesis, 2 nd Ed., T. W. Greene and P. G. M. Wuts, John Wiley & Sons, New York, 1991, hereby incorporated by reference.
[0148] Examples of hydroxy-protecting groups P, include, but are not limited to, methyl, benzyl, tetrahydropyranyl, tri(C 1 -C 6 )alkylsilyl such as t-butyldimethylsilyl, t-butyl, 2-methoxyethoxymethyl (MEM), 4-dimethylcarbamoylbenzyl and O-phenoxyacetyl ethers. The hydroxy-protecting group selected is preferably one that is easily removable in the reaction process.
[0149] Examples of suitable amino protecting groups include, but are not limited to, acetyl (Ac), benzoyl (Bz), trifluoroacetyl (Tfa), toluenesulfonyl (Tos), benzyl (Bn), triphenylmethyl (Trt), o-nitrophenyl-sulfenyl (Nps), benzyloxycarbonyl (Cbz or Z), t-butoxycarbonyl (Boc), allyloxycarbonyl (alloc), 9-fluorenylmethyloxycarbonyl (Fmoc), 2-bromo-benzyloxycarbonyl (2-Br—Z), 2-chloro-benzyloxycarbonyl (2-Cl—Z), t-butyl-dimethylsilyloxycarbonyl, [2-(3,5-dimethoxyphenyl)-propyl-2-oxycarbonyl] (Ddz), 2,2,2-trichloroethyloxycarbonyl (Troc), biphenylylisopropyloxycarbonyl (Bpoc), and o-nitrobenzyloxycarbonyl.
[0150] Throughout this specification, certain abbreviations are employed having the following meanings, unless specifically indicated otherwise.
[0151] AcOH=Acetic Acid
[0152] ADDP=1,1′-(azodicarbonyl)dipiperidine
[0153] BSA=Bovine Serum Albumin
[0154] DCM=Dichloromethane
[0155] DEAD=Diethyl azodicarboxylate
[0156] DIEA=Diisopropylethylamine
[0157] DMAP=Di(methyl)aminopyridine
[0158] DMF=N,N-dimethylformamide
[0159] DMSO=Dimethylsulfoxide
[0160] EA=Ethyl acetate
[0161] EDCl=1-ethyl-3-(3-dimethylaminopropyl) carbodiimide
[0162] EDTA=Ethylenediamine tetraacetic acid
[0163] EGTA=Ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid
[0164] Et 2 O=Diethyl ether
[0165] EtOAc=Ethyl acetate
[0166] EtOH=Ethanol
[0167] Et 3 N=Triethylamine
[0168] HEPES=N-(2-hydroxyethyl)piperazine-N-ethanesulfonic acid
[0169] LAH=Lithium Aluminum Hydride
[0170] MeOH=Methanol
[0171] MeI=Methyl Iodide
[0172] Oms=Mesylate
[0173] Otos=Tosylate
[0174] Phe=Phenyl
[0175] Pt=Protecting Group
[0176] PyBOP=Benzotriazole-1-yl-oxy-tris-pyrrolidino-phosphonium hexafluorophosphate
[0177] TBAF=Tetrabutylammonium fluoride
[0178] TEA=Triethylamine
[0179] TFA=Trifluoroacetic Acid
[0180] THF=Tetrahydrofuran
[0181] Tris-HCl=Tris[hydroxymethyl]aminomethyl hydrochloride
[0182] The synthesis of substituted N-benzyl-m-anisidines, compounds of formula (II), intermediates used in the synthetic route for select compounds of the invention, are known in the art.
[0183] Routes for synthesis of substituted N-benzyl-m-anisidines include alkylation (Hoerlein; Chem. Ber.; 87; 1954; 463, 467, 468), reductive amination (Nussbaumer, P.; et. al.; J Med Chem.; 37; 24; 1994; 4079-4084) and reduction of the corresponding N-benzoyl-m-anisidine (Pratt; McGovern; J. Org. Chem.; 29; 1964; 1540, 1542). Additionally, N-benzyl-N-phenyl-malonamic acid methyl ester, a compound of formula (III) below, is a known compound, a variant of one of the intermediates elucidated in the synthesis that follows (Wee, A.; Tetrahedron, 50; 3; 1994; 609-626).
[0184] Routes to the synthesis of 4-phenyl-1,2,3,4-tetrahydroisoquinolines are also known in the literature (Maryanoff, B., et. al., J. Org. Chem., 46, 1981, 355-360;Schwan, T. et. al., J. Heterocycl. Chem., 1974, 11, 807; and references therein).
[0185] Schemes 1-8 below depict synthesis routes for producing compounds of the formula (I).
[0186] Compounds of formula (I) wherein X 2 and X 3 are each carbonyl, X 1 and X 4 are each absent and R 3 is —CH 2 —R 6 , may be produced according to the process outlined in Scheme 1. The process of Scheme 1 is particularly preferred for preparation of compounds of formula (I) wherein A is incorporated into the molecule via reaction with a suitably selected unsymmetrically substituted anhydride; wherein A is a substituted alkyl; and wherein it is desired to have the substituent closer to the R 1 X 1 R 2 N portion of the compound of formula (I).
[0187] More specifically, a protected aniline derivative of formula (IV), wherein Pt represents a protecting group, a known compound or compound prepared by known methods, is reacted with a suitably substituted aldehyde of the formula (V), wherein R 3A is selected from hydrogen, aryl, heterocyclyl, aralkyl, diarylalkyl, heterocyclo-alkyl, tri-halomethyl, alkylamino, dialkylamino, alkylaminoalkyl, arylamino, diarylamino or lower alkyl;, in the presence of a reducing agent such as sodium cyanoborohydride, sodium triacetoxyborohydride, and the like, under dehydrating conditions, for example, in an acid alcohol solution such as acidic methanol or in a solution of titanium tetraisopropoxide in DCM, to produce the corresponding secondary aniline derivative of formula (VI).
[0188] The secondary aniline derivative of formula (VI) is coupled with a suitably selected, protected dicarboxylic acid of formula (VII), wherein Pt′ is a protecting group or with an anhydride of the desired substituent A, to produce the corresponding acid-amide of formula (VIII).
[0189] When the secondary aniline derivative of formula (VI) is coupled with a cyclic anhydride of the desired substituent A, such as glutaric anhydride and the like, the anhydride ring is subjected to ring opening, preferably at a temperature between about room temperature and about 110° C., in an organic solvent such as chloroform, toluene, and the like.
[0190] When the secondary aniline derivative of formula (VI) is coupled with a protected dicarboxylic acid of formula (VII), the protecting group is then removed by hydrolysis, using an inorganic base such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and the like, in an alcohol or in an organic solvent/water mixture such as methanol, ethanol, THF/water, preferably lithium hydroxide in THF/water.
[0191] The acid-amide compound of formula (VIII) is activated using a known coupling agent, such as EDCl and the like, and coupled with a suitably substituted amine of formula (IX), in an organic base such as TEA, DIEA, and the like, in the presence-of an organic solvent such as THF, DMF, DCM and the like, to produce the corresponding diamide of formula (X).
[0192] Alternatively, the acid-amine compound of formula (VIII) may be converted to the corresponding acid chloride with a reagent such thionyl chloride, oxalyl chloride, and the like, and then coupled to the substituted amine of formula (IX) to produce the diamide of formula (X).
[0193] The compound of formula (X) is deprotected by known methods [for example, when the protecting group is methyl ether, the methyl group is removed with boron tribromide in dichloromethane at −78° C.; when the protecting group is t-butyldimethylsilylether, the silyl group is removed with tetrabutylammonium fluoride in THF] to produce the corresponding compound of formula (XI).
[0194] The compound of formula (XI) is reacted with a suitably substituted compound of formula (XII), wherein W represents a leaving group such as halogen, OMS, OTos, and the like, in the presence of a base such as sodium hydride, potassium carbonate, and the like, in an organic solvent such as DMF, THF, and the like, to produce the corresponding compound of formula (Ia). Alternatively, when W is OH, the compound of formula (XI) may be reacted directly, under Mitsunobu conditions, to a suitably substituted compound of formula (XII).
[0195] Compounds of formula (I) wherein X 2 and X 3 are each carbonyl, X 1 and X 4 are each absent and R 3 is —CH 2 —R 6 may alternatively be prepared according to the process outlined in Scheme 2.
[0196] Accordingly, a suitably substituted nitrobenzene of formula (XIII), a compound prepared by known methods, is reacted with a suitably substituted compound of formula (XII), wherein W represents a leaving group such as halogen, OMS, OTos, and the like, in the presence of a base such as sodium hydride, triethylamine, and the like, in an organic solvent such as DMF, THF, and the like, to produce the corresponding compound of formula (XIV).
[0197] The nitro group on the compound of formula (XIV) is reduced by known methods, for example by hydrogenation over palladium on carbon in ethyl acetate, to produce the corresponding compound of formula (XV).
[0198] The compound of formula (XV) is reacted with a suitably substituted aldehyde of formula (V), wherein R 3A is as previously defined, in the presence of a reducing agent such as sodium cyanoborohydride, sodium triacetoxyborohydride, and the like, under dehydrating conditions, for example, in an acid alcohol solution such as acidic methanol or in a solution of titanium tetraisopropoxide in DCM, to produce the corresponding compound of formula (XVI).
[0199] The compound of formula (XVI) is reacted with a suitably selected anhydride of the desired A substituent, optionally in an organic solvent such as THF, DMF, DCM, and the like, to produce the corresponding compound of formula (XVII). When reacting with a cyclic anhydride of the desired substituent A, such as glutaric anhydride and the like, the anhydride ring is subjected to ring opening, preferably at a temperature between about room temperature and about 110° C., in an organic solvent such as chloroform, toluene, and the like.
[0200] The compound of formula (XVII) is coupled with a suitably substituted amine of formula (IX), in the presence of a coupling agent, such as PyBOP, and the like, in an organic solvent such as THF, DMF, DCM, and the like, to produce the corresponding compound of formula (Ib).
[0201] Compounds of formula (I) wherein X 2 and X 3 are each carbonyl, X 1 and X 4 are each absent and R 3 is —CH 2 —R 6 , may alternatively be prepared according to the process outlined in Scheme 3. This process is particularly preferred for preparation of compounds of formula (I) wherein A is incorporated into the molecule via reaction with a suitably selected, unsymmetrically substituted anhydride; wherein A is a substituted alkyl; and wherein it is desired to have the substituent distal to the R 1 X 1 R 2 N portion of the compound of formula (I).
[0202] More specifically, a suitably substituted amine of formula (IX) is reacted with a suitably selected anhydride of the desired A substituent, in an organic solvent such as THF, DMF, DCM, and the like, to produce the corresponding compound of formula (XVIII). When the compound of formula (IX) is coupled with a cyclic anhydride of the desired A substituent, such as glutaric anhydride and the like, the anhydride ring is subjected to ring opening, preferably at a temperature between about room temperature and about 110° C., in an organic solvent such as chloroform, toluene, and the like.
[0203] The compound of formula (XVIII) is coupled with a suitably substituted compound of formula (XVI), prepared as in Scheme 2 above, in an organic solvent such as THF, DMF, DCM and the like, after conversion of the compound of formula (XVIII) to the corresponding acid chloride using a reagent such as thionyl chloride, oxalyl chloride, and the like, to produce the corresponding compound of formula (Ib).
[0204] Alternatively, the compound of formula (XVIII) may be coupled directly with a suitably substituted compound of formula (XVI), optionally in the presence of a coupling agent such as PyBrop, and the like, in an organic solvent such as THF, DMF, DCM, and the like.
[0205] Compounds of formula (I) wherein X 1 and X 3 are each absent, X 2 is carbonyl, and X 4 is carbonyl or sulfonyl, may be prepared according to the process outlined in Scheme 4.
[0206] More specifically, an anhydride of the desired substituent A is reacted with a suitably substituted compound of formula (XIV), prepared as outlined in scheme 2, in an organic solvent such as THF, DMF, DCM and the like, to produce the corresponding compound of formula (XIX).
[0207] The compound of formula (XIX) is coupled with a suitably substituted amine of formula (IX), in the presence of a coupling agent, such as PyBOP, and the like, in an organic solvent such as THF, DMF, DCM and the like, to produce the corresponding compound of formula (XX).
[0208] The compound of formula (XX) is selectively reduced, by known methods, for example, by reacting with sodium cyanoborohydride in AcOH (Tetrahedron Letters, 10, 763-66, 1976), to produce the corresponding compound of formula (XXI).
[0209] The compound of formula (XXI) is reacted with an appropriately selected and suitably substituted isocyanate of formula (XXII), wherein R 3A is a previously defined, or a sulfonyl chloride of formula (XXIII) or a carbonyl chloride of formula (XXIV), in an organic solvent such as THF, DMF, DCM and the like, to produce the corresponding compound of formula (Ic).
[0210] Compounds of formula (I) wherein X 1 and X 4 are each carbonyl or sulfonyl and X 2 and X 3 are each absent, may be prepared according to the process outlined in Scheme 5. This process is particularly preferred for the preparation of compounds of formula (I) wherein A is -cyclohexyl-methyl-, -cyclopentyl-methyl and -cyclopentenyl-methyl-.
[0211] Accordingly, a trityl-protected compound of formula (XXV), wherein A 1 is cycloalkyl, cycloalkenyl, alkyl-cycloalkyl, aryl or alkyl-aryl, a known compound or compound prepared by known methods, [for example by the method disclosed in K. Barlos, D. Theodoropoulos, and D. Papaioannou in J. Org. Chem. 1982, 47, 1324-1326], is coupled to a suitably substituted compound of formula (XIV), prepared according to Scheme 2 above, using a coupling agent such as PyBOP, and the like, to produce the corresponding compound of formula (XXVI).
[0212] The compound of formula (XXVI) is subjected to reduction of the carbonyl group using known reducing agents, for example borane dimethylsulfide at reflux, lithium aluminum hydride in THF, and the like, to produce the corresponding compound of formula (XXVII).
[0213] The compound of formula (XXVII) is reacted with an appropriately selected and suitably substituted isocyanate of formula (XXII), wherein R 3A is as previously defined, sulfonyl chloride of formula (XXIII) or carbonyl chloride of formula (XXIV), in an organic solvent such as DCM, toluene, chloroform, and the like, to produce the corresponding compound of formula (XXVIII).
[0214] The compound of formula (XXVIII) is deprotected by removal of the trityl protecting group, using a solution of trifluoroacetic acid in dichloromethane, to produce the corresponding compound of formula (XXIX).
[0215] The compound of formula (XXIX) is reacted with a suitably substituted aldehyde of formula (XXX), wherein R 1A is selected from the group consisting of hydrogen, aryl, aralkyl, heterocyclyl, diarylalkyl, heterocyclyl-alkyl, and lower alkyl; wherein the alkyl, aryl, heterocyclyl or amino group may be substituted with one or more substituents independently selected from halogen, hydroxy, nitro, carboxy, cyano, amino, dialkylamino, lower alkoxy, lower alkyl, tri-halomethyl, alkylamino, carboxy or alkoxycarbonyl; by known methods, [for example by reductive amination or by the method of R. Mattson, et. al., in J. Org. Chem. 1990, 55, 2552-2554 using stepwise addition of titanium tetraisopropoxide neat or in a dichloromethane, followed by addition of methanol and sodiumcyanoborohydride], to produce the corresponding compound of formula (XXXI).
[0216] The compound of formula (XXXI) is reacted with an appropriately selected and suitably substituted isocyanate of formula (XXXII), wherein R 2A is selected from aryl, aralkyl, heterocyclyl, heterocyclyl-alkyl, diarylalkyl, tri-halomethyl, arylamino or lower alkyl, or a sulfonyl chloride of formula (XXXIII) or a carbonyl chloride of formula (XXXIV), or an anhydride of formula (XXXXVII) in an organic solvent such as DCM, toluene, and the like, to produce the corresponding compound of formula (Id). When the compound of formula (XXXI) is reacted with a sulfonyl chloride of formula (XXXIII) or a carbonyl chloride of formula (XXXIV), the reaction is carried out with further addition of an organic base such as TEA, DIPEA, and the like.
[0217] Compounds of formula (I) wherein A is a substituted alkyl may alternatively be prepared according to the process outlined in Scheme 6.
[0218] More specifically, a suitably substituted compound of formula (XVI), prepared as described in Scheme 2 above, is coupled with an appropriately selected, Fmoc protected compound of formula (XXXV), in an organic solvent such as DCM, DMF, and the like, to produce the corresponding compound of formula (XXXVI).
[0219] The compound of formula (XXXVI) is deprotected by removal of the Fmoc protecting group by known methods [for example by treating with piperidine in DMF], to produce the corresponding compound of formula (XXXVII).
[0220] The compound of formula (XXXVII) is reacted with a suitably substituted aldehyde of formula (XXX), wherein R 1A is as previously defined, in the presence of a reducing agent such as sodium cyanoborohydride, and the like, under dehydrating conditions, for example in an acid alcohol solution such as acidic methanol or in a solution of titanium tetraisopropoxide in DCM, followed by addition of methanol and sodium cyanoborohydride, to produce the corresponding compound of formula (XXXVIII).
[0221] The compound of formula (XXXVIII) is coupled with an appropriately selected and suitably substituted isocyanate of formula (XXXII), wherein R 2A is as previously defined, sulfonyl chloride of formula (XXXIII) or carbonyl chloride of formula (XXXIV), in an organic solvent such as DCM, and the like, in the presence of an organic base such as TEA, DIEA, and the like, to produce the corresponding compound of formula (Ie).
[0222] Optionally, the compound of formula (XXXVIII) may be further reacted with a second equivalent of the compound of formula (XXX) to yield a derivative of the compound of formula (XXXVIII), wherein the leftmost amine nitrogen is di-substituted with the —CH 2 —R 1A group, wherein R 1A is as previously defined.
[0223] Compounds of formula (I), particularly those wherein X 1 and X 3 are each absent, X 2 is carbonyl and X 4 is carbonyl or sulfonyl may be prepared according to the process outlined in Scheme 7. This process is particularly preferred for preparation of compounds of formula (I) wherein A is contains a non-hydrogen substituent alpha to the right-hand most amine nitrogen.
[0224] Accordingly, a suitably substituted compound of formula (XV), prepared as in Scheme 2 above, is alkylated with an appropriately selected compound of formula (XXXIX), ins an organic solvent such as DCM, chloroform, and the like, to produce the corresponding compound of formula (XXXX).
[0225] The compound of formula (XXXX) is coupled with an appropriately selected and suitably substituted isocyanate of formula (XXII), wherein R 3A is as previously defined, sulfonyl chloride of formula (XXIII) or carbonyl chloride of formula (XXIV), in an organic solvent such as DCM, and the like, to produce the corresponding compound of formula (XXXXI). When the compound of formula (XXXX) is reacted with a sulfonyl chloride of formula (XXXIII) or a carbonyl chloride of formula (XXXIV), the reaction is run in the presence of an organic base such as TEA, DIEA, and the like.
[0226] The compound of formula (XXXXI) is subjected to hydrolysis of the methyl ester, in the presence of an inorganic base such as sodium hydroxide, and the like, to produce the corresponding compound of formula (XXXXII).
[0227] The compound of formula (XXXXII) is coupled with a suitably substituted amine of formula (IX), in the presence of a coupling agent such as PyBOP, and the like, in an organic solvent such as DCM, and the like, to produce the corresponding compound of formula (If).
[0228] Compounds of formula (I), particularly those wherein X 1 and X 4 are each carbonyl or sulfonyl and X 2 and X 3 are each absent may be prepared according to the process outlined in Scheme 8
[0229] Accordingly, wherein A 1 is an oxo and cyano substituted cycloalkyl, an oxo and cyano substituted cycloalkenyl, an oxo and cyano substituted cycloalkyl-alkyl, an oxo-alkyl and cyano substituted aryl or an oxo-alkyl and cyano-alkyl substituted aryl-alkyl, a known compound or compound prepared by known methods, is reacted with a compound of formula (XV), prepared as outlined in Scheme 2, in the presence of a reducing agent such as sodium cyanoborohydride, and the like, under dehydrating conditions, for example in an acid alcohol solution such as acidic methanol, to produce the corresponding compound of formula (XXXXIII).
[0230] The compound of formula (XXXXIII) is reacted with an appropriately selected and suitably substituted isocyanate of formula (XXII), wherein R 3A is as previously defined, sulfonyl chloride of formula (XXIII) or carbonyl chloride of formula (XXIV), in an organic solvent such as DCM, and the like, to produce the corresponding compound of formula (XXXXIV). When the compound of formula (XXXXIII) is reacted with a sulfonyl chloride of formula (XXIII) or a carbonyl chloride of formula (XXIV), the reaction is run in the presence of an organic base such as TEA, DIEA, and the like.
[0231] The cyano functional group on the compound of formula (XXXXIV) is reduced by known methods, for example by treatment with lithium aluminum hydride, in an organic solvent such as THF, and the like, to produce the corresponding compound of formula (XXXXV).
[0232] The compound of formula (XXXXV) is reacted with a suitably substituted aldehyde of formula (XXX), wherein R 1A is as previously defined, in the presence of a reducing agent such as sodium cyanoborohydride, and the like, under dehydrating conditions, for example in an acid alcohol solution such as acidic methanol or in a solution of titanium tetraisopropoxide in DCM, followed by addition of methanol and sodium cyanoborohydride, to produce the corresponding compound of formula (XXXXVI).
[0233] The compound of formula (XXXXVI) is reacted with an appropriately selected and suitably substituted isocyanate of formula (XXXII), wherein R 2A is as previously defined, sulfonyl chloride of formula (XXXIII), or carbonyl chloride of formula (XXXIV), in an organic solvent such as DCM, and the like, to produce the corresponding compound of formula (Ig). When the compound of formula (XXXXVI) is reacted with a sulfonyl chloride of formula (XXXIII) or a carbonyl chloride of formula (XXXIV), the reaction is run in the presence of an organic base such as TEA, DIEA, and the like.
[0234] Compounds of formula (I) wherein R 1 , X 1 and R 2 are taken together (with the amine nitrogen) to form an oxo substituted heterocyclyl group, may be prepared according to the process outlined in Scheme 9.
[0235] More particularly, the compound of formula (XXIX), prepared as in Scheme 5, is reacted with a suitably substituted symmetric or asymmetric anhydride, a compound of formula (XXXXVII), preferably a symmetric anhydride, in an organic solvent such as toluene, DCM, and the like, to yield the corresponding compound of formula (XXXXVIII).
[0236] The compound of formula (XXXXVIII) is heated at an elevated temperature in the range of about 40-180° C., or treated with addition of an anhydride such as acetic anhydride, trifluoroacetic anhydride, and the like, in an organic solvent such as methylene chloride, toluene, 1,2-dichlorobenzene, and the like, to yield the corresponding compound of formula (Ih), wherein
[0237] represents the group wherein R 1 , R 2 and X 1 are taken together (with the amine nitrogen) to form a cyclic oxo substituted heterocyclyl.
[0238] Wherein the compound of formula (XXXXVII) is an asymmetric anhydride, (a compound of the formula R 2 ′—C(O)—C(O)—R 2 ″, wherein R 2 ′ and R 2 ″ are different), the R 2 group which is coupled onto the compound of formula (XXIX) may be readily determined by one skilled in the art, based on the relative reactivities of the carbonyl groups adjacent to the R 2 ′ and R 2 ″ groups.
[0239] It is generally preferred that the respective product of each process step be separated from other components of the reaction mixture and subjected to purification before its use as a starting material in a subsequent step. Separation techniques typically include evaporation, extraction, precipitation and filtration. Purification techniques typically include column chromatography (Still, W. C. et. al., J. Org. Chem. 1978, 43, 2921), thin-layer chromatography, HPLC, acid-base extraction, crystallization and distillation.
[0240] Where the compounds according to this invention have at least one chiral center, they may accordingly exist as enantiomers. Where the compounds possess two or more chiral centers, they may additionally exist as diastereomers. It is to be understood that all such isomers and mixtures thereof are encompassed within the scope of the present invention.
[0241] Where the processes for the preparation of the compounds according to the invention give rise to mixture of stereoisomers, these isomers may be separated by conventional techniques such as preparative chromatography. The compounds may be prepared in racemic form, or individual enantiomers may be prepared either by enantiospecific synthesis or by resolution. The compounds may, for example, be resolved into their component enantiomers by standard techniques, such as the formation of diastereomeric pairs by salt formation with an optically active acid, such as (−)-di-p-toluoyl-d-tartaric acid and/or (+)-di-p-toluoyl-l-tartaric acid followed by fractional crystallization and regeneration of the free base. The compounds may also be resolved by formation of diastereomeric esters or amides, followed by chromatographic separation and removal of the chiral auxiliary. Alternatively, the compounds may be resolved by enzymatic resolution or by using a chiral HPLC column.
[0242] To prepare the pharmaceutical compositions of this invention, one or more compounds or salts thereof, as the active ingredient, is intimately admixed with a pharmaceutical carrier according to conventional pharmaceutical compounding techniques, which carrier may take a wide variety of forms depending on the form of preparation desired for administration, e.g., oral or parenteral. In preparing the compositions in oral dosage form, any of the usual pharmaceutical media may be employed. Thus for liquid oral preparations, such as for example, suspensions, elixirs and solutions, suitable carriers and additives include water, glycols, oils, alcohols, flavoring agents, preservatives, coloring agents and the like; for solid oral preparations such as, for example, powders, capsules and tablets, suitable carriers and additives include starches, sugars, diluents, granulating agents, lubricants, binders, disintegrating agents and the like. Because of their ease in administration, tablets and capsules represent the most advantageous oral dosage form, in which case solid pharmaceutical carriers are obviously employed. If desired, tablets may be sugar coated or enteric coated by standard techniques. For parenterals, the carrier will usually comprise sterile water, though other ingredients, for example, for purposes such as aiding solubility or for preservation, may be included. Injectable suspensions may also be prepared, in which case appropriate liquid carriers, suspending agents and the like may be employed. The pharmaceutical compositions herein will preferably contain per dosage unit, e.g., tablet, capsule, powder, injection, teaspoonful and the like, from about 5 to about 500 mg of the active ingredient, although other unit dosages may be employed.
[0243] In therapeutic use for treating disorders of the gastrointestinal system in mammals, the compounds of this invention may be administered in an amount of from about 0.5 to 100 mg/kg 1-2 times per day orally. In addition the compounds may be administered via injection at 0.1-10 mg/kg per day. Determination of optimum dosages for a particular situation is within the capabilities of formulators.
[0244] In order to illustrate the invention, the following examples are included. These examples do not limit the invention. They are meant to illustrate and suggest a method of practicing the invention. Although there are other methods of practicing this invention, those methods are deemed to be within the scope of this invention.
EXAMPLE 1
N-trityl-cis-3-aminocyclohexanecarboxylic acid
[0245] Adapting the method of K. Barlos, D. Papaioannou and D. Theodoropoulos, JOC, 1982, 47, 1324-1326, cis-3-aminocyclohexanecarboxylic acid was protected as the N-trityl derivative.
[0246] TMSCI (26.1 ml, 0.205 mmol) was added to a suspension of cis-3-aminocyclohexanecarboxylic acid (29.4 g, 0.205 mmol) suspended in a 5:1 solution of CH 2 Cl 2 —CH 3 CN (500 ml) at room temperature. The mixture was heated at reflux for 2 hours and then allowed to cool to ambient temperature. TEA (57.2 ml, 0.410 mmol) was added dropwise to the mixture, followed immediately by portionwise addition of triphenylmethyl chloride (57.2 g, 0.205 mmol). After stirring for 18 h, MeOH was added to the mixture to give a homogeneous solution. The mixture was evaporated down to dryness and the resultant residue partitioned between Et 2 O and 10% citric acid (1:1, 800 ml total). The ether layer was collected and combined with an ether extraction (150 ml) of the citric acid layer. The combined ether fractions were then extracted with 2 M NaOH (3×250 ml) and water (1×100 ml). The aqueous layers were washed with ether (2×150 ml). After cooling to 0° C., the aqueous layer was acidified to pH 7 with concentrated HCl and extracted with ethyl acetate (3×200 ml). The combined extracts were dried over MgSO 4 and evaporated down to give a white foam, 67.4 g, 85% yield.
[0247] MS 384 (M − )
[0248] [0248] 1 H NMR (CDCl 3 ) δ0.44-0.95 (br m, 3H), 0.97-1.22 (br m, 2H), 1.30-1.48 (br m, 1H), 1.53-1.79 (br m, 2H), 1.8-2.04 (br m, 1H), 2.10-2.29 (br m, 1H), 6.9-7.24 (m, 9H), 7.36-7.59 (m, 6H).
EXAMPLE 2
1-(2-(3-nitrophenoxy)ethyl)pyrrolidine
[0249] Following the procedure disclosed in GB 924961; 1959; Chem.Abstr.; 59; 9883b; 1963.
[0250] 3-nitrophenol (3.29 g, 23.7 mmol) in DMF (20 ml) was added dropwise to 60% NaH (2.65 g, 66.2 mmol) in 30 ml DMF at 0° C., under nitrogen. The reaction was stirred until H 2 (g) evolution ceased. 1-(2-chloroethyl)pyrrolidine hydrochloride (5.63 g, 33.1 mmol) was then added portionwise. The mixture was stirred at room temperature for 18 h. The reaction mixture was quenched with 2N NaOH (50 ml) and the desired product extracted into ether (3×50 ml). The combined ether layers were washed (2×50 ml) with water, dried over MgSO 4 , and evaporated to dryness in vacuo. The residue was purified through a silica gel plug using 10% ethyl acetate/hexane to remove the impurities and then the desired product was eluted off with 40% ethyl acetate/hexane containing 2% Et 3 N to yield a pale yellow oil.
[0251] MS 237 (MH + )
[0252] [0252] 1 H NMR (CDCl 3 ) δ1.78-1.88 (m, 4H), 2.55-2.66 (m, 4H), 2.94 (t, J=5.8 Hz, 2H), 4.18 (t, J=5.8 Hz, 2H), 7.23-7.28 (m, 1H), 7.42 (virtual t, J=8.2 Hz, 1H), 7.75-7.76 (m, 1H), 7.80-7.83 (m, 1H).
EXAMPLE 2B
2-(2-(3-aminophenoxy)ethyl)-1-methylpyrrolidine
[0253] 3-aminophenol (0.74 g, 6.8 mmol) in DMF (10 ml) was added dropwise to 95% NaH (0.49 g, 20.4 mmol) in 10 ml DMF at 0° C., under nitrogen. The reaction was stirred until H 2 (g) evolution ceased. 2-(2-chloroethyl)-1-methylpyrrolidine hydrochloride (1.25 g, 6.8 mmol) was then added portionwise. The mixture was stirred at room temperature for 18 h. The reaction mixture was quenched with 1N NaOH (50 ml) and the desired product extracted into ether (3×50 ml). The combined ether layers were washed (2×50 ml) with water, dried over MgSO 4 , and evaporated to dryness in vacuo. The residue was purified on silica gel by flash chromatography using 2% TEA in ethyl acetate to give an oil.
[0254] MS 221 (MH + )
[0255] [0255] 1 H NMR (CDCl 3 ) δ1.46-2.31 (m, 8H), 2.34 (s, 3H), 3.08 (ddd, J=8.3, 7.6, 2.4 Hz, 1H), 3.64 (br s, 2H), 3.89-4.08 (m, 2H), 6.20-6.36 (m, 3H), 7.04 (t, J=8.0 Hz, 1H).
EXAMPLE 2C
1-(2-(3-aminophenoxy)ethyl)piperidine
[0256] Following the procedure as described in Example 2B, 19.9 g (0.182 mol) of 3-aminophenol was converted into the title compound as a light yellow oil.
[0257] MS 221 (MH + )
[0258] [0258] 1 H NMR (CDCl 3 ) δ1.38-1.50 (m, 2H), 1.52-1.66 (m, 4H), 2.43-2.56 (m, 4H), 2.75 (t, J=6.1 Hz, 2H), 3.65 (s br, 2H) 4.07 (t, J=6.1 Hz, 2H), 6.22-6.35 (m, 3H), 7.04 (t, J=7.9 Hz, 1H).
EXAMPLE 3
1-(2-(3-aminophenoxy)ethyl)pyrrolidine
[0259] A mixture of 1-(2-(3-nitrophenoxy)ethyl)pyrrolidine (3.49 g, 14.8 mmol), 10% palladium on carbon (400 mg) and ethyl acetate (20 ml) was reduced under 50 psi hydrogen for 10 h. The reaction mixture was filtered through Celite 545 and the product extracted into 1M HCl (3×20 ml). The acidic layer was washed with ether (2×20 ml) and then the pH adjusted to >10 with 2M NaOH. The aqueous layer was extracted with ether (3×20 ml), dried over MgSO 4 and concentrated in vacuo. The product was eluted through a silica gel pad (75% ethyl acetate/hexane/1% Et 3 N) to yield the product as a pale yellow oil.
[0260] MS 207 (MH + )
[0261] [0261] 1 H NMR (CDCl 3 ) δ1.72-1.80 (m, 2H), 2.54-2.71 (m, 2H), 2.88 (t, J=8.2 Hz, 2H), 3.48-3.79 (br s, 2H), 4.07 (t, J=8.2Hz, 2H), 6.22-6.39 (m, 3H), 7.05 virtual t, J=9.1 Hz,1H).
EXAMPLE 4
N-(3-(2-(1-pyrrolidino)ethyloxy)phenyl)-cis-3-(triphenylmethylamino)cyclohexylcarboxamide
[0262] Benzotriazole-1-yl-oxy-tris-pyrrolidino-phosphonium hexafluorophosphate (PyBop) (4.8 g, 9.3 mmol) was added to a mixture of N-trityl-cis-3-aminocyclohexanecarboxylic acid (3.3 g, 8.4 mmol), 1-(2-(3-aminophenoxy)ethyl)pyrrolidine (1.4 g, 7.0 mmol), DIEA (1.6 ml, 9.3 mmol) and dichloromethane (30 ml). After stirring overnight, the crude mixture was evaporated onto silica gel and purified by flash chromatography (20% EtOAc/2% Et 3 N/hexane, then 60% EtOAc/2% Et 3 N/hexane). The title compound was isolated as a white foam upon evaporation.
[0263] Yield: 3.2 g, 78%
[0264] MS 596 (MNa + ), 574 (MH + ), 332 (MH + -trt), 243 (trt + ).
EXAMPLE 5
N-(3-(2-(1-pyrrolidino)ethyloxy)phenyl)-N-cis-3-(triphenylmethylamino)cyclohexylmethylamine
[0265] LAH (220 mg, 5.8 mmol) was added to N-(3-(2-(1-pyrrolidino)ethyloxy)phenyl)-cis-(3-(triphenylmethyl)amino)cyclohexylmethyl-carboxamide (2.1 g, 3.7 mmol) in THF (10ml) under nitrogen at ambient temperature. The reaction was refluxed for 8 h, cooled to room temperature and quenched with a saturated solution of Rochelle's salt (potassium sodium tartrate). The precipitate was filtered away through Celite 545 leaving the crude product as an oil upon evaporation. The residue was dissolved in EtOAc (20 ml), washed with water (2×20 ml) and dried over MgSO 4 . Evaporation of the solvent yielded the product as a white foam.
[0266] MS 582 (MNa + ), 560 (MH + ), 318 (MH + -trt), 243 (trt + ).
EXAMPLE 6
N-(3-(2-(1-pyrrolidino)ethyloxy)phenyl)-N-[cis-3-(triphenylmethylamino)cyclohexylmethyl]-4-fluorophenylcarboxamide
[0267] 4-fluorobenzoyl chloride (0.34 ml, 2.9 mmol) in dichloromethane (5 ml) was added dropwise to a solution of N-(3-(2-(1-pyrrolidino)ethyloxy)phenyl)-N-cis-3-(triphenylmethylamino)cyclohexylmethylamine (1.4 g, 2.6 mmol), triethylamine (0.40 ml, 2.9 mmol) and dichloromethane (10 ml). After 3 h the reaction was quenched with 2M NaOH (3 ml) and extracted with DCM (3×20 ml). The organic layers were combined, dried over MgSO 4 and evaporated onto silica gel in vacuo. The product was purified by chromatography on a silica gel column, preconditioned with Et 3 N, using 50% EtOAc/2% Et 3 N/hexane. The product was isolated as a white foam.
[0268] MS 682 (MH + ), 440 (MH + -trt), 243 (trt + ).
EXAMPLE 7
N-(3-(2-(1-pyrrolidino)ethyloxy)phenyl)-N-[cis-(3-aminocyclohexyl)methyl]-4-fluorophenylcarboxamide
[0269] 10% TFA/1 % triethylsilane/DCM (35 ml) was added to N-(3-(2-(1-pyrrolidino)ethyloxy)phenyl)-N-[cis-3-(triphenylmethylamino)cyclohexylmethyl]-4-fluorophenylcarboxamide (1.75 g, 2.57 mmol). Upon completion, after 3 h, the desired product was extracted into 1 M HCl (3×20 ml). The extracts were washed with DCM (2×20 ml) and the aqueous layer (cooled to 0 C.) made basic with NaOH. Extraction of the aqueous layer with EtOAc (3×20 ml) yielded, upon drying (MgSO 4 ) and evaporation, the product as a pale yellow oil.
[0270] MS 462 (MNa + ), 440 (MH + ).
EXAMPLE 8
[0271] [0271]
[0272] To a stirred solution of N-(3-(2-(1-pyrrolidino)ethyloxy)phenyl)-N-(cis-3-amino-cyclohexyl)methyl-4-fluorophenylcarboxamide (1.0 g, 2.3 mmol) and benzaldehyde (0.26 ml, 2.5 mmol) in toluene (4 ml) was added titanium(IV) isopropoxide (0.82 ml, 2.8 mmol) under nitrogen. After 18 h, EtOH (0.8 ml) was added followed by portionwise addition of sodium triacetoxyborohydride (0.63 g, 2.8 mmol). After an additional 4 h of stirring, the reaction was quenched with 2M NaOH. The precipitate was filtered off through Celite 545, then dried over MgSO 4 and evaporated in vacuo to yield crude N-(3-(2-(1-pyrrolidino)ethyloxy)phenyl)-N-(cis-3-(benzylamino)cyclohexyl)methyl-4-fluorophenylcarboxamide.
[0273] The crude residue (1.2 g) was taken up in DCM (4 ml), followed by addition of trimethylacetyl chloride (0.31 ml, 2.5 mmol). The reaction was complete in less than 2 h. The reaction was neutralized with a saturated solution of NaHCO 3 , extracted with DCM (3×10 ml), dried over MgSO 4 and evaporated onto silica gel. The product was purified by flash chromatography (50% EtOAc/1% Et 3 N/hexane) to yield a white foam (690 mg). Addition of 1M HCl (1.2 ml, 1.2 mmol) in ether to the free base in ether (5 ml) yielded the product.
[0274] MS 614 (MH + ); HPLC (RT 4.11 min.)
EXAMPLE 9
N-(3-(2-(1-pyrrolidino)ethyloxy)phenyl)-N-(cis-3-(triphenylmethylamino)cyclohexyl)methyl-N′-phenylurea
[0275] Phenylisocyanate (0.31 ml, 2.9 mmol) was added dropwise to a solution of N-(3-(2-(1-pyrrolidino)ethyloxy)phenyl)-N-(cis-3-(triphenylmethylamino)-cyclohexyl)methylamine (1.4 g, 2.6 mmol) in dichloromethane (5 ml). After stirring for 18 h, the reaction mixture was evaporated onto silica gel. The title product was isolated by chromatography (50% EtOAc/hexane, then 60% EtOAc/2% Et 3 N/hexane) as a white foam.
[0276] MS 679 (MH + ), 437 (MH + -trt), 243 (trt + ).
EXAMPLE 10
[0277] [0277]
[0278] By the method of example 7 and 8, N-(3-(2-(1-pyrrolidino)ethyloxy)phenyl)-N-(cis-3-(triphenylmethyl)aminocyclohexyl)methyl-N′-phenylurea, benzaldehyde and trimethylaacetyl chloride were reacted to yield the title compound.
[0279] MS 437 (MH + ).
EXAMPLE 11
N-(3-(2-(4-morpholino)ethyloxy)phenyl)-N-[(cis-3-(3-nitrobenzyl)aminocyclohexylmethyl]-4-fluorophenylcarboxamide
[0280] To a stirred solution of N-(3-(2-(4-morpholino)ethyloxy)phenyl)-N-(cis-3-aminocyclohexyl)methyl-4-fluorophenylcarboxamide (5.3 g, 12 mmol) and 3-nitrobenzaldehyde (2.0 g, 13 mmol) in DCM (30 ml) was added titanium(IV) isopropoxide (4.6 ml, 16 mmol) under nitrogen. After 3 h, EtOH (20 ml) was added followed by portionwise addition of sodium cyanoborohydride (1.0 g, 16 mmol). The reaction was stirred overnight, then quenched with 2M NaOH. The resulting precipitate was filtered off through Celite 545, the filtrate was dried over MgSO 4 and evaporated in vacuo to yield crude product.
[0281] MS 591 (MH + ).
EXAMPLE 12
[0282] [0282]
[0283] Trichloroacetyl chloride (0.93 ml, 8.3 mmol) was added to crude N-(3-(2-(4-morpholino)ethyloxy)phenyl)-N-[(cis-3-(3-nitrobenzyl)aminocyclohexylmethyl]-4-fluorophenylcarboxamide (4.9 g, 8.3 mmol) taken up in DCM (20 ml). The reaction was complete in less than 2 h. The reaction was neutralized with a saturated solution of NaHCO 3 , extracted into DCM (3×15 ml), dried over MgSO 4 and evaporated onto silica gel. The product was purified by chromatography (50% EtOAc/2% Et 3 N/hexane) to yield the title compound as a white foam.
[0284] MS 736 (MH + ); HPLC (RT 4.11 min.).
EXAMPLE 13
N-(3-(2-(4-morpholino)ethyloxy)phenyl)-N-{(cis3-(benzylamino)cyclohexyl)methyl}-N′-phenylurea
[0285] By the method of example 11, N-(3-(2-(4-morpholino)ethyloxy)phenyl)-N-(cis-3-aminocyclohexyl)methyl-N′-phenylurea and benzaldehyde were converted into the title compound.
[0286] MS 543 (MH + ).
EXAMPLE 14
[0287] [0287]
[0288] By the method of example 9, N-(3-(2-(4-morpholino)ethyloxy)phenyl)-N-{(cis-3-(benzylamino)cyclohexyl)methyl}-N′-phenylurea and phenylisocyanate were converted into the title compound.
[0289] MS 662 (MH + ); HPLC (RT 4.38 min.).
EXAMPLE 15
[0290] [0290]
[0291] By the method of example 12, N-(3-(2-(4-morpholino)ethyloxy)phenyl)-N-{(cis-3-(benzylamino)cyclohexyl)methyl}-N′-phenylurea and 2-naphthalenesulfonyl chloride were converted into the title compound.
[0292] MS 733 (MH + ); HPLC (RT 4.97 min.).
EXAMPLE 16
[0293] [0293]
[0294] By the method of example 12, N-(3-(2-(4-morpholino)ethyloxy)phenyl)-N-cis-3-(aminocyclohexyl)methyl}-N′-phenylurea and trichloroacetyl chloride were converted into the title compound.
[0295] MS 599 (MH + ); HPLC (RT 3.59 min.).
EXAMPLE 17
1-(2-(3-amino-2-methylphenoxy)ethyl)pyrrolidine
[0296] By the method of examples 2 and 3, 1-(2-chloroethyl)pyrrolidine hydrochloride and 2-methyl-3-nitrophenol were converted into the title compound.
[0297] MS 221 (MH + )
[0298] [0298] 1 H NMR (CDCl 3 ) δ1.75-1.86 (m, 4H), 2.05 (s, 3H), 2.62-2.67 (m, 4H), 2.92 (t, J=6.0 Hz, 2H), 3.60 (br s, 2H), 4.09 (t, J=6.0 Hz, 2H), 6.33 (virtual d, J=8.1 Hz, 2H), 6.95 (virtual t, J=9.1 Hz,1H).
EXAMPLE 18
4-(2-(3-aminophenoxy)ethyl)morpholine
[0299] By the method of examples 2 and 3, 4-(2-chloroethyl)morpholine hydrochloride and 3-nitrophenol were converted into the title compound.
[0300] MS 223 (MH + )
EXAMPLE 19
N-(4-fluorophenylmethyl)-4-(2-(3-aminophenoxy)ethyl)morpholine
[0301] 4-fluorobenzaldehyde (1.3 ml, 12 mmol) was added to a stirred solution of 4-(2-(3-aminophenoxy)ethyl)morpholine (2.2 g, 10 mmol) in 2% AcOH/MeOH (40 ml). After 1 h, sodium cyanoborohydride (0.50 g, 12 mmol) was added portionwise to the mixture. After an additional 2 h, 2M NaOH (20ml) was added and the mixture evaporated to give a tan residue. The residue was partitioned between 1N HCl and ether. The acid layer was washed 2×40 ml with ether and then adjusted to a pH>10 with NaOH. The product was extracted into ethyl acetate (3×50 ml), dried over magnesium sulfate and evaporated down to yield the title compound as a brown oil.
[0302] MS 331 (MH + )
[0303] [0303] 1 H NMR (CDCl 3 ) δ2.50-2.65 (m, 4H), 2.76 (t, J=5.8 Hz, 2H), 3.68-3.82 (m, 4H), 4.01-4.16 (m, 3H), 4.29 (d, J=5.3 Hz, 2H), 6.18 (s, 1H), 6.22-6.33 (m, 2H), 6.97-7.13 (m, 3H), 7.29-7.40 (m, 2H).
EXAMPLE 20
[0304] [0304]
[0305] N-(4-fluorophenylmethyl)-4-(2-(3-amino-phenoxy)ethyl)morpholine (260 mg, 0.79 mmol) and glutaric anhydride (95 mg, 0.79 mmol) were combined and refluxed in chloroform (3 ml) overnight. To the organic solution at ambient temperature was added, N-benzylphenethylamine (170 mg, 0.79 mmol), DIEA (0.28 ml, 1.6 mmol) and PyBOP (420 mg, 0.80 mmol). The sample was concentrated down upon completion (<3 h). Chromatography on silica gel with 1% MeOH in ethyl acetate provided the title compound.
[0306] MS 638 (MH + ); HPLC (RT 4.32 min.)
[0307] [0307] 1 H NMR (CDCl 3 ) (approximately 1:1 mixture of rotomers) δ1.85-2.01 (m, 2H), 2.08-2.22 (m, 2H), 2.26-2.43 (m, 2H), 2.78 (t, J=7.4 Hz, 2H), 2.9-3.13 (m, 2H), 3.32-3.74 (m, 6H), 3.88-4.05 (m, 4H), 4.24-4.42 (m, 3H), 4.54 (s, 1 Hz, 4.88 (m, 2H), 6.45 (s,1H), 6.59 (t, J=6.2 Hz, 1H), 6.78-7.00 (m, 3H), 7.03-7.39 (m, 13H).
EXAMPLE 21
[0308] N-(3-nitrophenyl)methyl)phenethylamine
[0309] Sodium cyanoborohydride (0.18 g, 2.7 mmol) was added to a preformed imine of phenethylamine (0.28 g, 2.3 mmol) and 3-nitrobenzaldehyde (0.38 g, 2.5 mmol) in 2% AcOH—MeOH. The reaction was quenched after 4 h with a saturated solution of sodium bicarbonate and the solvent removed in vacuo. The resultant residue was partitioned between water and dichloromethane (20 ml total). The aqueous layer extracted with DCM (3×20ml), the organic extracts were combined and dried over sodium sulfate. The crude material was used without further purification.
[0310] MS 257 (MH + ).
EXAMPLE 22
N-(4-fluorophenyl)methyl)-N-[3-(2-(1-pyrrolidino)ethyloxy)-2-methylphenyl]-N′-(2-phenethyl)-1,5-pentyldiamide
[0311] A solution of N-(4-fluorophenylmethyl)-1-(2-(3-amino-2-methylphenoxy)-ethyl)pyrrolidine (4.85 g, 14.8 mmol) and glutaric anhydride (2.02 g, 17.7 mmol) in toluene (30 ml) was heated to reflux. After 12 h the reaction was concentrated in vacuo. PyBop (430 mg, 0.81 mmol)was added to the solution of crude N-(4-fluorophenylmethyl-N-3-(2-(1-pyrrolidino)ethyloxy)-2-methylphenylcarboxamidopentyric acid (330 mg, 0.74 mmol) and phenethylamine (90 mg, 0.74 mmol) in DMF (2 ml). The reaction mixture was stirred overnight, diluted with 2 M NaOH and then extracted with ether (3×20 ml). The combined extracts were washed with a brine solution and dried over MgSO 4 . The crude material was purified by flash chromatography on silica gel using 80% ethyl acetate/2% Et 3 N/hexane as eluent to yield the title compound as a brown oil.
[0312] MS 546 (MH + ).
EXAMPLE 23
[0313] [0313]
[0314] 60% sodium hydride (˜3 mg, 0.07 mmol) was added to N-(4-fluorophenyl)methyl)-N-[3-(2-(1-pyrrolidino)ethyloxy)-2-methylphenyl]-N′-(2-phenethyl)-1,5-pentyldiamide (30 mg, 0.06 mmol) in DMF (1 ml). After 10 min, methyl-3-(bromomethyl)benzoate (16 mg, 0.07 mmol) was added to the stirred solution. The reaction was quenched with sodium bicarbonate after 18 h and then extracted (3×15 ml) into ether. The title product was isolated by semi-prep HPLC (C-18 column, 30% CH 3 CN/water/0.1% TFA to 60% CH 3 CN/water/0.1% TFA). Note: the methyl ester was hydrolyzed under the acidic mobile phase conditions.
[0315] MS 680 (MH + ); HPLC (RT 3.53 min.)
EXAMPLE 24
N-(3-tert-butyldimethylsiloxyphenyl)4-fluorobenzylamine
[0316] By the method of example 19, 4-fluorobenzaldehyde (4.41 g, 35.5 mmol) and 3-aminophenol (3.60 g, 32.3 mmol) were reacted to yield a clear oil (6.75 g) upon silica gel purification (15% ethyl acetate/hexane).
[0317] MS 218 (MH + ).
[0318] The resultant N-3-hydroxyphenyl-4-fluorobenzylamine (4.25 g, 19.6 mmol) and imidazole (1.33 g, 19.6 mmol) were combined in DMF (20 ml) and treated with tetrabutyldimethylsilyl chloride (3.05 g, 19.6 mmol). After 5 h, the reaction was diluted with saturated NaHCO 3 and extracted with ether. The ether layers were combined, washed with water and dried over MgSO 4 . The title product was isolated by flash chromatography (15% EA/hexane) as a clear oil (3.75 g, 58%).
[0319] MS 332 (MH + )
[0320] [0320] 1 H NMR (CDCl 3 ) δ0.12 (s, 6H), 0.81 (s, 9H), 3.84 (br s, 1H), 4.12 (s, 2H), 5.96 (t, J=2.2 Hz, 1H), 6.10 (td, J=8.0, 2.2 Hz, 2H), 6.84-6.91 (m, 3H), 7.16-7.21 (m, 2H).
EXAMPLE 25
N-((4-fluorophenyl)methyl)-N-(3-hydroxyphenyl)-N′-(2-phenethyl)-N′-benzyl-1,5-pentyldiamide (#175)
[0321] N-(4-fluorophenyl)methyl)-N-(3-tert-butyldimethylsiloxyphenyl)-N′-(2-phenethyl)-N′-benzyl-1,5-pentyldiamide (4.2 g, 6.6 mmol), prepared by method of example 20, in THF (10 ml) was treated with 1 M TBAF (7.3 ml, 7.3 mmol). The reaction, complete in less than 15 h, was quenched with 0.1 M HCl. The aqueous layer was extracted with ethyl acetate (3×30 ml) and the organic layers dried over MgSO 4 . The crude material was purified by flash chromatography using 50% ethyl acetate/hexane as eluent. The title compound was recovered as a clear oil.
[0322] MS 525 (MH + )
[0323] [0323] 1 H NMR (CDCl 3 ) (approximately 1:1 mixture of rotomers) δ1.84-2.02 (m, 2H), 2.08-2.21 (m, 2H), 2.25 (t, J=7.3 Hz, 1H), 2.34 (t, J=7.3 Hz, 1H), 2.72-2.86 (m, 2H), 3.38-3.59 (m, 2H), 4.37 (s, 1H), 4.55 (s, 1H), 4.76 (s, 1H), 4.78 (s, 1H), 6.40 (t, J=7.7 Hz, 1H), 6.52 (m, 1H), 6.77-6.93 (m, 3H), 7.03-7.39 (m, 13H), 8.41 (s, 1H).
EXAMPLE 26
[0324] [0324]
[0325] To N-(4-fluorophenyl)methyl)-N-(3-hydroxyphenyl)-N′-(2-phenethyl)-N′-benzyl-1,5-pentyldiamide (75 mg, 0.14 mmol) in THF (1 ml) was added 1-(2-hydroxyethyl)piperazine (22 mg, 0.17 mmol), tri-n-butylphosphine (0.14 ml, 0.57 mmol), and ADDP (86 mg, 0.34 mmol). After 18 h the reaction was diluted with a solution of saturated sodium bicarbonate and then extracted into ethyl acetate (3×15 ml). The combined organic layers were dried over MgSO 4 and evaporated down to an oil. The title product was isolated by semi-prep HPLC (C-18 column, 30% CH 3 CN/water/0.1% TFA to 60% CH 3 CN/water/0.1% TFA).
[0326] MS 637 (MH + ); HPLC (RT 3.34 min.).
EXAMPLE 27
N-[3-(2-(4-morpholino)ethoxy)phenyl]-N′-(2-phenethyl)-N′-benzyl-1,4-butyldiamide
[0327] Applying the procedure used in Example 20, with substitution of 4-(2-(3-aminophenoxyethyl)morpholine and succinic anhydride for N-(4-fluorophenylmethyl)-4-(2-(3-aminophenoxy)ethyl)morpholine and glutaric anhydride respectively, yielded the title compound as a white solid.
[0328] MS 516 (MH + )
EXAMPLE 28
[0329] [0329]
[0330] N-[3-(2-(4-morpholino)ethoxy)phenyl]-N′-(2-phenethyl)-N′-benzyl-1,4-butyldiamide (0.39 g, 0.75 mmol) was dissolved in a solution of sodium borohydride (0.14 g, 3.8 mmol) in THF (4 mL). Acetic acid (0.22 ml, 3.75 mmol) was slowly added to the reaction mixture at 0° C. After 18 h, the reaction was quenched with 1N HCl, neutralized with saturated sodium bicarbonate and the THF layer collected. The organic layer was dried over MgSO 4 , filtered and then treated with phenyl isocyanate (0.080 ml, 0.75 mmol) to yield crude solid product. The crude material was purified by flash chromatography using 50% ethyl acetate/hexane as eluent. The title compound was recovered as a clear oil.
[0331] MS 621 (MH + );
[0332] [0332] 1 H NMR (CD 3 OD) (approximately 1:1 mixture of rotomers) δ1.72-1.97 (m, 2H), 2.25 (t, J=6.8 Hz, 1H), 2.45 (t, J=6.8 Hz, 1H), 2.73-2.94 (m, 2H), 3.18-3.42 (m, 2H), 3.48-3.91 (m, 10H), 3.97-4.15 (m, 2H), 4.40 (t, J=4.9 Hz, 2H), 4.49 (s, 1H), 4.63 (s, 1H), 6.89-7.06 (m, 4H), 7.09-7.48 (m, 15H).
EXAMPLE 29
2,2-dimethylpropylbenzylamine
[0333] Step A: N-3-chlorobenzyltrimethylacetamide
[0334] 3-chlorobenzylamine (3.54 g, 25 mmol) was added dropwise to trimethylacetyl chloride (2.65 ml, 21.5 mmol) and Et 3 N (3.5 ml, 25 mmol) in DCM (25 ml). After two hours, the reaction mixture was washed with 1 N HCl and the organic layer collected and dried over MgSO 4 . N-3-chlorobenzyltrimethylacetamide was precipitated from DCM/hexane as a white solid, 3.95 g,
[0335] MS 192 (MH + ).
[0336] Step B:
[0337] N-benzyltrimethylacetamide (2.35 g, 12.3 mmol) in THF (10 ml) was refluxed with 1M borane-tetrahydrofuran (13.5 ml) for 15 hours. The reaction was quenched with 1N HCl, washed with ether, and the aqueous layer adjusted to a pH>10. The aqueous layer was extracted with EtOAc and the organic layers combined and dried over MgSO 4 .
[0338] The title compound may be alternatively be prepared according to the procedure described in Overman, Larry E.; Burk, Robert M.; TELEAY; Tetrahedron Lett.; 25; 16; 1984; 1635-1638
EXAMPLE 30
[0339] [0339]
[0340] EDCl-MeI (0.33 g, 1.1 mmol) was added to N-(4-fluorophenylmethyl)-4-(2-(3-aminophenoxy)ethyl)morpholine (0.27 g, 0.83 mmol) (Prepared in Example 19), and Fmoc-L-Phe-OH (0.39 g, 1.0 mmol) in CHCl 3 (15 mL). After 8 h, the reaction was diluted with a saturated solution of NaHCO 3 , extracted with DCM and dried over MgSO 4 . The desired product was isolated by flash chromatography (50-100% EA/hexane) to yield a white solid.
[0341] MH+700.
EXAMPLE 31
[0342] [0342]
[0343] The product prepared in Example 29, (31 mg, 0.044 mmol) was dissolved in DCM (1 mL) and deprotected with piperidine (7.4 μl, 0.082 m mol) to yield a white solid upon evaporation.
[0344] MH+478.
[0345] The crude product was then dissolved along with benzaldehyde (16 μl, 0.16 mmol) in 2% AcOH /MeOH (1 ml). To this solution was added NaBH 3 CN (20 mg, 0.32 mmol) in two portions. After 1 h, the solvent was evaporated and the residue partitioned between 1N HCl and ether. The aqueous layer was washed with ether, adjusted to pH ˜10 with 2N NaOH and extracted with DCM. The organic layer was dried over MgSO 4 and evaporated down. Hydrocinnamoyl chloride (12 μl, 0.08 mmol) was then added to the residue dissolved in DCM (2 ml) and DIEA (16 μl, 0.09 mmol). The title compound was isolated by semi-prep HPLC as the TFA salt.
[0346] MH+700; HPLC (RT 5.16 mins).
EXAMPLE 32
[0347] [0347]
[0348] 4-(2-(3-amino-phenoxy)ethyl)morpholine (389 mg, 1.75 mmol) and methyl 3-bromomethylbenzoate (482 mg, 2.1 mmol) were reacted in CHCl 3 (5 mL), that contained Et 3 N (293 μl, 2.1 mmol). The reaction was refluxed for 16 h, until completion,as evidenced by disappearance of the starting aniline derivative on TLC (Rf 0.5 for product, ethyl acetate eluent)).
[0349] MS (MH+) 371
[0350] The reaction mixture was cooled and then treated with Et 3 N (293 μl, 2.1 mmol) and 4-fluorobenzoyl chloride (207 μl, 1.75 mmol). Upon completion, the reaction mixture was quenched with 1N NaOH and extracted 3 times with DCM. The organic layer was dried over MgSO 4 and evaporated down onto silica gel. The title compound was isolated by flash chromatography (gradient from 80% EA/hexane to 100% EA) to yield a white solid.
[0351] MS (MH+) 493
EXAMPLE 33
[0352] [0352]
[0353] The compound prepared in Example 31 (375 mg, 0.82 mmol) was refluxed in a mixture of 10% NaOH/EtOH (30 ml). After 2 h, the EtOH was evaporated under vacuum. The residue was diluted with 2N NaOH and washed with ether. The aqueous layer was then acidified to pH 1 with concentrated HCl and extracted with DCM. The organic layer was dried over MgSO4 and evaporated down. The residue was dissolved in DCM (10 mL) and partitioned into ten aliquots. One aliquot was treated with phenethylamine (12 mg, 0.10 mmol) and EDCl-MeI (29 mg, 0.10 mmol). After 16 h, the reaction mixture was washed 2×with water and evaporated down to yield a brown residue. The title compound was isolated by semi-prep HPLC (reverse phase, C-18) as the TFA salt.
[0354] MH+582; HPLC (RT 3.41 mins).
EXAMPLE 34
N-3-cyanocyclopentyl-4-(2-(3-amino-phenoxy)ethyl)morpholine
[0355] 4-(2-(3-aminophenoxy)ethyl)morpholine (2.15 g, 9.67 mmol) and 3-cyanocyclopentanone (1.06 g, 9.67 mmol) (prepared according to the process decsribed by Della, E.; Knill, A.; Aust, J. Chem.; 47; 10; 1994; 1833-1842) were combined in 1% AcOH/MeOH (50 ml). To this solution was added NaBH 3 CN (925 mg, 14.5 mmol) in portions. After 12 h, the solvent was evaporated off and the residue partitioned between saturated NaHCO 3 and ethyl acetate. The aqueous layer was extracted with ethyl acetate, the combined organic layers were dried over MgSO 4 and evaporated down. The title compound was purified by flash chromatography with ethyl acetate as the eluent, 2.1 g
[0356] MS (MH+) 316.
EXAMPLE 35
[0357] [0357]
[0358] Phenylisocyanate (0.65 ml, 5.9 mmol) was added to N-3-cyanocyclopentyl4-(2-(3-amino-phenoxy)ethyl)morpholine (1.88 g, 5.95 mmol) partially dissolved in THF (25 ml) at room temperature. After 15 h, crude material was placed on a silica gel column and eluted with ethyl acetate to give 680 mg of a yellow oil.
[0359] MS (MH+) 435.
EXAMPLE 36
[0360] [0360]
[0361] The product prepared in Example 34 (0.65 g, 1.5 mmol) dissolved in THF (10 ml) was added to 1M LAH (4.5 ml) at −78° C. and allowed to warm to room temperature. After 15 h, the reaction was quenched with a saturated solution of Rochelle's salt (potassium sodium tartrate). The precipitate was filtered away through Celite 545 to yield the crude product as an oil upon evaporation. The residue was dissolved in EtOAc, washed with water and dried over MgSO 4 . Evaporation of the solvent yielded the product as an oil.
[0362] (MH+) 439
EXAMPLE 37
[0363] [0363]
[0364] Sodium cyanoborohydride (34 mg, 0.54 mmol) was added to the product prepared in Example 35 (78 mg, 0.18 mmol) and 3-chlorobenzaldehyde (40 μl, 0.36 mmol) in 1% AcOH/MeOH (2 ml). After 6 hours the reaction was acidified with 1N HCl, then neutralized with 2N NaOH and extracted into dichloromethane.
[0365] (MH+) 563.
[0366] The organic layer was dried over MgSO 4 , cooled to 0° C. and then treated with trichloroacetyl chloride (20 μl, 0.18 mmol). The final product was isolated by flash chromatography (ethyl acetate).
[0367] (MH+) 707
EXAMPLE 38
[0368] [0368]
[0369] N-trityl-cis-3-aminocyclohexanecarboxylic acid (13.1 g, 34 mmol) was added to a solution of PyBop (17.7 g, 34 mmol) and DIEA (11.8 ml, 68 mmol) in DCM (70 mL) and stirred for 10 minutes. 1-(2-(3-aminophenoxy)ethyl)piperidine (6.8 g, 30.9 mmol) in DCM (30 mL) was added to the reaction mixture over the course of 20 mins. The coupled product was purified by flash chromatography (25% ethyl acetate/1% Et 3 N/hexane) and evaporated down to yield a white foam.
[0370] The foam was dissolved in THF (100 mL), treated with LAH (1.3 g, 34 mmol)and refluxed for 7 hrs. Upon cooling, the reaction mixture was alternately quenched with NaOH and water to yield a granular solid. The heterogenous reaction mixture was then filtered through Celite 545. The reduced product was extracted into ether from water. The combined organic layers were dried over MgSO 4 and evaporated to dryness.
[0371] The crude product and Et 3 N (4.7 ml, 34 mmol) were dissolved in DCM (100 mL). 4-fluorobenzoyl chloride (4.0 ml, 34 mmol) of was added dropwise to this solution. After 2 hours the reaction mixture was evaporated onto silica gel and then purified by flash chromatography (20% ethyl acetate/1% Et 3 N/hexane) to yield the title compound.
EXAMPLE 39
[0372] [0372]
[0373] The compound prepared as in Example 38, was dissolved in 20% TFA/1% TES/DCM and stirred for 1 hr. The reaction mixture was evaporated down to dryness. The crude material was partitioned between ether and 1N HCl. The aqueous solution was washed twice with ether, cooled to 0° C. and the pH adjusted to 12 with NaOH. The deprotected amine was extracted into DCM and dried over MgSO 4 .
[0374] Following the procedure as described in Example 8, the deprotected amine, 3-chlorobenzaldehyde and trichloroacetyl chloride were reacted to yield the title compound. The enantiomers were separated using a Chiralpak AD HPLC column.
EXAMPLE 40
[0375] [0375]
[0376] N-(3-(2-(4-morpholino)ethyloxy)phenyl)-N-(cis-3-aminocyclohexyl)methyl-4-fluorophenylcarboxamide (83 mg, 0.18 mmol) and 3,3-dimethylglutaric anhydride (28 mg, 0.20 mmol) were combined and heated at 90° C. in toluene (2 mL) for two hours. The reaction mixture was concentrated in vacuo and purified by semi-prep HPLC (C18 column, acetonitrile/water/0.1% TFA) to yield the title compound.
EXAMPLE 41
[0377] [0377]
[0378] N-(3-(2-(4-morpholino)ethyloxy)phenyl)-N-(cis-3-aminocyclohexyl)methyl-4-fluorophenylcarboxamide (83mg, 0.18 mmol) and phthalic anhydride (30 mg, 0.20 mmol) were dissolved in toluene (2 mL). The reaction was heated at 90° C. for two hours. To the reaction was then added acetic anhydride (0.2 ml, 2.1 mmol) and the reaction refluxed for an additional 15 hours. The reaction mixture was concentrated in vacuo and purified by semi-prep HPLC (C18 column, acetonitrile/water/0.1% TFA) to yield the title compound as a white solid.
EXAMPLE 42
In Vitro Testing
[0379] Motilin Receptor Binding
[0380] Rabbit colon was removed, dissected free from the mucosa and serosa, and diced into small pieces. The muscle tissue was homogenized in 10 volumes of 50 mM Tris-Cl, 10 mM MgCl 2 , 0.1 mg/ml bacitracin, and 0.25 mM Peflabloc, at pH 7.5 in a Polytron (29000 rpm, 4×15 seconds). The homogenate was centrifuged at 1000×g for 15 minutes and the supernatant discarded. The pellet was washed twice before being suspended in homogenizing buffer. The crude homogenate was resuspended through a 23 gauge needle before storing at −80° C. In a total volume of 0.5 ml, the binding assay contained the following components: buffer (50 mM Tris-Cl, 10 mM MgCl 2 , 1 mM EDTA, 15 mg/ml BSA, 5 mg/ml of pepstatin, leupeptin, aprotinin, and 0.15 mg/ml bacitracin), I 125 radio-labeled porcine motilin (50000-70000 cpm; specific activity 2000 Ci/mmole), test compound, and membrane protein. After 60 minutes at 30° C., the samples were cooled in ice, centrifuged in the cold at 13000×g for 1 minute. The pellet was washed twice with 1 ml of cold saline, the supernatant was aspirated, and the pellet at the bottom of the tube counted in a gamma counter. Non-specific binding was determined by the inclusion of 1 mM of unlabeled motilin. IC 50 values were determined from Kaleidograph curves.
EXAMPLE 43
In Vitro Testing
[0381] Human Antrum Tissue
[0382] Human antrum tissue from Analytical Biological Services (Wilmington, Delaware) was prepared as a motilin receptor preparation in the following manner. The muscle tissue was homogenized in 10 volumes of 50 mM Tris-Cl, 10 mM MgCl 2 , 0.1 mg/ml bacitracin, and 0.25 mM Peflabloc, pH 7.5) in a Polytron (29000 rpm, 4×15 seconds). The homogenate was centrifuged at 1000×g for 15 minutes and the supernatant discarded. The pellet was washed twice before being suspended in homogenizing buffer. The crude homogenate was resuspended through a 23 gauge needle before aliquoting and storing at −80° C. The human cloned receptor was prepared from HEK 293 cells overexpressed with the motilin receptor. Cell pellets were thawed and resuspended in 2-3 volumes of homogenizing buffer (10 mM Tris-Cl, 0.2 mM MgCl 2 , 5 mM KCl, 5 μg/ml aprotinin, leupeptin, and pepstatin A, and 50 μg/ml bacitracin, pH 7.5) and allowed to sit on ice for 15-20 minutes. The suspension was homogenized on ice in a Dounce type homogenizer using 15 strokes. Sucrose and EDTA were added to a final concentration of 0.25M and 1 mM, respectively, and mixed with a few additional strokes. The material was centrifuged at 400×g for 5 minutes, and the supernatant saved. The pellet was re-resuspended twice with 5 ml homogenizing buffer and rehomogenized as before, and the supernatants combined. The supernatant was centrifuged at 100000×g for 1 hour. The pellet is retained and resuspended with 5 ml of homogenizing buffer through a 19 g and 25 g needle. The suspension is aliquoted and stored at −80° C. until used. The binding assay contains the following components (50 mM HEPES, 5 mM MgCl 2 , and 1 mM EGTA, pH 7.0, 15 mg/ml BSA, 10 μg/ml aprotinin, leupeptin, and pepstatin A, 0.25 mg/ml bacitracin, and 10 mM benzamidine), 125I-radiolabelled porcine motilin (50000-70000 cpm; specific activity 2000 Ci/mmol), test compound, and membrane protein. After 60 minutes at 30° C., the samples are placed on ice and centrifuged for 1 minute at 13000×g. The pellet is washed twice with 1 ml cold saline, and after removal of the final supernatant, the pellet at the bottom of the tube is counted in a gamma counter. Non-specific binding is measured by the inclusion of 1 μM unlabelled motilin. IC 50 values were determined from Kaleidograph curves.
[0383] 125I-Motilin Binding to Human Antral Stomach Membranes and the Human Cloned Receptor:
Human Antrum IC 50 (nM) 1.0 ± 0.1 Human Cloned Receptor IC 50 (nM) 3.55 ± 0.05
EXAMPLE 44
In Vivo Testing
[0384] Rabbit Tissue Bath Procedure
[0385] One New Zealand White rabbit (Covance) of either sex was euthanized with an IV injection of Sleepaway. The duodenum was quickly excised, the lumen rinsed with saline to clean, and the tissue placed in cold, aerated (95% O2-5% CO 2 ) Tyrodes buffer (NaCl 136.9 mM, KCl 2.7 mM, CaCl 2 1.8 mM, MgCl 2 1.04 mM, NaH 2 PO 4 0.42 mM, NaHCO 3 11.9 mM, Glucose 5.55 mM, pH 7.4). The duodenum, being kept moist at all times, was cleaned of any excess mesenteric tissue, and then cut into 3 cm segments starting at the proximal end. Sixteen tissue segments were usually prepared from each duodenum. These segments were tied on both ends with 3-0 silk suture (Ethicon). One end of the tissue was attached to an S-hook on a custom made glass support rod (Crown Glass Co., Somerville) and the rod plus tissue were placed in a 15 ml isolated tissue bath (Radnoti). The other end of the glass rod was attached to a Grass Force Displacement Transducer FT03. The tissue was maintained in room temperature Tyrodes buffer pH 7.4 and continually gassed with 95% O 2 -5% CO 2 . The tissues were adjusted to 1.0 g resting tension and maintained at that tension throughout the equilibration period. An MI2 Tissue Bath Computer was used to record and analyze data.
[0386] The tissues were washed twice during a 30 minute equilibration period and readjusted to 1 g resting tension as necessary. After equilibration the tissues were challenged with 3 μM Carbachol (Carbamoyicholine Chloride-Sigma). After maximal contraction was attained, the tissues were washed 3 times with Tyrodes. The tissues were allowed a 20 minute resting/equilibration period, during which time they were washed once and readjusted to 1 g resting tension. The tissues were challenged a second time with 3 μM Carbachol, and this contraction was considered as maximal, or 100% contraction. The tissues were washed 3 times, equilibrated for 10 minutes, washed again and readjusted to 1 g resting tension. Vehicle or test compound in 30% DMSO-50 mM HEPES was added directly to the bath and the tissues were incubated for 20 minutes. Test compounds and vehicle were run in duplicate. The tissues were then challenged with 3 nM Porcine Motilin (Bachem) and when maximum contraction was attained another 3 μM aliquot of Carbachol was added to see if the test compound inhibited this contraction.
[0387] The percent inhibition by test compound of the motilin induced contraction was calculated by first determining the ratio of the vehicle contractions with Motilin compared to the Carbachol contractions. This Tissue Adjustment Factor (TAF) was used to determine the value for the potential uninhibited contraction with Motilin for each tissue. The percent inhibition was then determined by dividing the actual Motilin contraction in treated tissues by the potential uninhibited contraction and subtracting this number from 1. IC 50 values were determined by graphing results with Kaleidograph graphing program.
[0388] Tables 18 and 19 below list molecular weight, % Inhibition and IC 50 values measured for select compounds of the present invention.
TABLE 18 Mol. Wt. * Rabbit Colon Human Antrum Tissues ID Cal'd (MH + ) % Inh @ 1 mM IC 50 (μM) % Inh @ 1 μM IC 50 (μM) IC 50 (μM) 1 621 621 35 2 656 656 9 3 620 620 35 4 624 624 75 0.69 5 635 635 40 6 634 634 24 7 638 638 42 8 545 545 18 9 580 580 27 10 544 544 29 11 548 548 0 12 594 594 4 13 558 558 21 14 562 562 25 15 531 531 21 16 566 566 21 17 530 530 12 18 534 534 0 19 545 545 5 20 580 580 8 21 544 544 34 22 548 548 23 23 607 607 48 24 642 642 6 25 606 606 23 26 621 621 22 27 656 656 22 28 620 620 13 29 624 624 18 30 559 559 17 31 594 594 39 32 558 558 12 33 562 562 16 34 573 573 7 35 608 608 17 36 572 572 32 37 576 576 11 39 709 707 4 40 662 662 11 41 677 677 58 42 627 627 50 43 675 675 74 0.73 44 697 697 4 45 692 692 67 1.16 46 737 737 32 47 723 721 23 48 637 637 67 0.656 49 817 817 37 50 757 757 32 51 711 711 73 0.65 52 661 661 45 53 709 709 52 54 731 731 42 55 726 726 48 56 771 771 27 57 733 733 15 58 706 705 38 59 757 755 23 60 757 755 65 0.66 61 718 717 55 62 756 755 58 63 723 721 55 64 738 737 32 65 733 732 80 0.035 0.027 66 757 755 39 67 688 687 75 0.957 68 689 688 73 0.66 69 572 572 0 70 547 547 0 71 643 643 43 72 598 597 40 73 549 549 25 74 693 693 29 75 633 633 19 76 587 587 26 77 537 537 19 78 585 585 10 79 607 607 39 80 602 602 34 81 647 647 56 82 783 783 0 83 723 723 3 86 697 697 16 90 692 691 95 0.49 >0.3 91 601 600 36 92 760 758 80 93 736 735 100 0.09 0.0205 94 741 740 28 95 726 724 51 96 759 758 71 1.68 >.03 97 721 720 56 98 760 758 75 0.76 99 760 758 62 0.572 100 709 708 78 101 774 774 59 102 729 729 47 103 734 734 2 104 712 712 30 105 664 664 80 0.39 0.03 106 714 714 69 1.05 107 820 820 29 108 676 676 70 0.815 109 760 760 27 110 718 718 35 111 726 724 72 0.88 112 740 740 70 0.48 113 695 695 51 114 700 700 49 115 678 678 26 116 630 630 61 0.772 117 680 680 17 118 726 726 58 119 786 786 22 120 642 642 69 0.954 121 684 684 37 122 691 690 64 0.84 123 736 736 8 124 640 640 70 0.904 125 665 665 25 128 624 624 75 0.23 129 638 638 90 0.058 130 610 610 8 131 623 622 19 132 658 658 10 133 672 672 6 134 626 626 0 135 694 694 8 136 672 672 43 137 644 644 30 138 582 582 36 139 586 586 13 140 638 638 45 141 672 672 21 142 670 670 17 143 596 596 0 144 638 638 54 145 590 590 35 146 654 654 32 147 688 688 61 0.49 148 622 622 19 149 699 699 27 150 680 680 0 151 713 712 1 152 700 700 0 153 636 636 89 0.081 0.03 154 692 692 62 0.41 155 676 676 34 156 554 554 18 157 642 642 16 158 601 600 37 159 652 652 83 0.275 160 652 652 61 0.96 161 664 664 22 162 672 672 85 0.178 0.021 163 658 658 85 0.174 0.019 164 624 624 84 0.194 0.048 165 624 624 63 0.55 166 636 636 23 167 674 674 42 168 640 640 36 169 638 638 97 0.046 0.24 170 638 638 81 0.163 0.185 171 650 650 63 0.462 0.23 172 688 688 40 173 654 654 84 0.29 0.28 174 692 691 0 175 525 525 0 176 636 636 32 177 640 640 52 >1.0 178 624 624 100 0.07 0.015 179 637 637 85 0.24 0.023 180 622 622 99 0.014 0.011 181 596 596 100 0.093 0.012 182 636 636 94 0.022 0.053 183 661 661 2 184 711 711 6 185 671 671 0 186 722 722 0 187 610 610 100 0.229 188 650 650 100 0.247 0.092 189 652 652 70 0.3 190 666 666 99 0.2 0.067 191 622 622 27 192 638 638 15 193 650 650 7 194 596 596 23 195 624 624 62 196 636 636 100 0.006 0.004 197 667 667 85 0.009 0.0076 198 672 672 100 0.107 199 691 690 91 0.1 200 690 690 92 0.041 201 657 657 93 0.057 0.0168 202 691 690 100 0.33 0.23 203 649 649 98 0.24 204 662 662 89 0.029 0.003 205 683 683 76 0.1 206 688 688 60 0.77 207 636 636 87 0.064 208 734 733 91 0.009 0.048 209 724 722 84 0.059 0.021 210 689 688 90 0.086 0.024 211 720 719 100 0.014 0.072 212 710 708 89 0.058 0.036 213 675 674 84 0.058 0.027 214 614 614 95 0.029 0.024 215 680 680 100 0.084 216 600 600 100 217 634 634 98 218 661 660 98 0.024 0.035 219 706 705 98 0.0076 220 636 636 92 0.042 221 598 598 94 223 707 705 100 0.041 224 672 671 98 0.039 225 611 611 93 0.021 226 648 648 100 0.032 0.009 227 683 682 100 0.025 228 650 650 100 0.025 229 614 614 100 0.01 230 614 614 100 0.072 231 661 660 88 0.13 232 698 698 62 233 650 650 89 0.17 234 652 652 86 0.218 235 662 61 236 724 53 237 662 96 0.168 238 724 98 0.097 239 724 0.073 240 724 >0.70 241 728 14 242 704 36 243 728 35 244 698 42 245 758 40 246 678 73 247 726 41 248 704 86 0.760 249 716 22 250 642 0 251 604 0 252 636 15 253 600 30 254 606 25 255 655 22 256 600 27 257 586 0 258 580 34 259 665 17 260 644 30 261 654 0 262 550 18 263 655 11 264 570 6 265 638 67 266 598 5 267 624 21 268 598 17
[0389] [0389] TABLE 19 Cal'd Mol. % Inh @ 1 mM % Inh @ 1 mM ID Wt. MW (MH + ) (Rabbit colon) (Human antrum) 38 577.4 576 22 84 542.7 543 12 85 577.2 577 28 87 611.6 611 22 88 592.8 593 0 89 561.7 562 3 222 619.8 620 83 83
[0390] While the foregoing specification teaches the principles of the present invention, with examples provided for the purpose of illustration, it will be understood that the practice of the invention encompasses all of the usual variations, adaptations and/or modifications as come within the scope of the following claims and their equivalents.
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The present invention relates to novel substituted diamine derivatives for the formula
wherein R 1 , R 2 , R 3 , R 4 , X 1 , X 2 , X 3 , X 4 , A, Y and n are as described in the specification, pharmaceutical compositions containing them and intermediates used in their manufacture. More particularly, the compounds of the invention are motilin receptor antagonists useful for the treatment of associated conditions and disorders such as gastrointestinal reflux disorders, eating disorders leading to obesity and irritable bowel syndrome.
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FIELD OF THE INVENTION
[0001] The present invention relates to a tube closure, for example a poster tube closure, and to a tube system.
BACKGROUND TO THE INVENTION
[0002] Poster tubes are rigid tubes, usually cylindrical, within which posters, artwork or photographs are stored in rolled-up form for protection during transportation, e.g. when posted from a supplier to a customer.
[0003] The tube is usually closed-off at each or one end by an end-plug or closure 1 of the form shown in FIG. 1 . Conventional closures are circular, push-fit plugs that are shaped to snugly locate within the end of the tube, comprising a solid planar base 2 , with an upstanding perimeter wall 3 and a circumferential lip 4 inwards of the wall that allows the recipient to grip the closure to pull-it out of the tube to access the poster inside.
[0004] Where the contents are of value, or liable to be tampered with, the closures are usually secured using adhesive tape or staples. Tape looks unsightly and can easily be removed and replaced. Stapling is more secure, but requires an air stapler to puncture the tube, and presents a problem in that a tool is needed to remove the staples which, if not properly removed, may damage the poster as it is drawn out of the tube.
SUMMARY OF THE INVENTION
[0005] A first aspect of the invention provides a tube closure, comprising a plug member for locating substantially entirely within an open end of a tube, the plug member being provided with a breakable region configured in use to be broken by user action in order to enable access beneath to enable its extraction from a tube within which it is located.
[0006] The tube closure is particularly a poster tube closure, e.g. comprising a plug member for locating within an open end of a poster tube, the plug member being provided with a breakable region configured in use to be broken by user action in order to enable access beneath to enable its extraction from a tube within which it is located.
[0007] The closure therefore provides a neat and convenient way of closing a poster tube which provides a visible indication of tampering via the breakable region. It will be appreciated that the breakable region can be broken in part only to provide access and removal.
[0008] A poster tube in this context can also be used for carrying similar articles such as artwork and photographs.
[0009] The plug member may have an upper and lower surface, and wherein the upper surface is generally planar with no upstanding perimeter wall so that in use it fits flush with the end of a poster tube.
[0010] The breakable region may be formed within the perimeter.
[0011] The breakable region may be defined by a plurality of perforations.
[0012] The perforations may define a tab-like breakable region part of which is not breakable, for example with the perforations not entirely bounding the breakable region so that part remains intact whilst still enabling removal of the closure and a visible indication of the break.
[0013] A circumferential wall may be provided that extends downwards relative to the plug member's upper surface and is arranged in use to locate within a tube to provide a snug fit.
[0014] One or more ribs may be provided on the circumferential wall, i.e. its outer side, to ensure the snug fit.
[0015] The closure may be formed of polyethylene.
[0016] A second aspect provides a poster tube closure, comprising a plug member for locating within an end of a poster tube, the plug member comprising a substantially planar closure surface with upper and lower faces, wherein a perimeter wall extends downwardly from the lower face for gripping the wall of a poster tube when inserted, and wherein the upper face has a frangible or weakened area arranged in use to be broken by user action to permit removal of the plug member and a visible indication of said breakage.
[0017] A third aspect provides a poster storage system, comprised of a hollow tube with at least one open end, and a removable plug member shaped and dimensioned to close-off the open end in accordance with any preceding definition.
[0018] A fourth aspect provides a poster storage system, comprised of a hollow tube with at least one open end, and a removable plug member shaped and dimensioned to close-off the open end, wherein the plug member on its external side has no upstanding projection or lip so that it can fit flush within the tube's open end, and has a breakable region accessible from the external side which is configured to be broken by user action to enable extraction of the plug from the tube from underneath.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention will now be described by way of example only with reference to the accompanying diagrammatic drawings in which:
[0020] FIG. 1 is a perspective view of a known tube closure, which is useful for understanding the background of the invention;
[0021] FIGS. 2 a -2 c are different views of a tube closure according to the invention;
[0022] FIG. 3 is a side sectional view of the tube closure of FIG. 2 when located within a poster tube;
[0023] FIG. 4 is a top plan view of a further embodiment tube closure according to the invention;
[0024] FIG. 5 is a top plan view of a still further embodiment tube closure according to the invention;
[0025] FIG. 6 is a side view of a still further embodiment tube closure according to the invention; and
[0026] FIG. 7 is a side view of the FIG. 6 closure when located within a poster tube, shown in section.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Embodiments described herein relate to a poster tube closure and poster tube system. In this regard, it is to be understood that the term ‘poster tube’ can also encompass tubes for storing flexible artwork and photographs that can be rolled for storage.
[0028] Referring to FIGS. 2( a )-( c ) , a first embodiment poster tube closure (hereafter “closure”) 10 is shown in different views. The closure is formed of plastics material, e.g. polyethylene (high or low density) but could be formed of any other plastic, metal, rigid cardboard or similar material.
[0029] The closure 10 is a disk shaped member having a planar upper surface 12 and a lower surface (not visible). A side wall 14 extends downwards from the perimeter of the lower surface. Around the side wall 14 is or are formed one or more gripping ribs 16 , which is or are projections which in use are configured to firmly grip the inner surface of a poster tube to retain the closure 10 in position. Each rib 16 in this case is circumferential, but can be broken into several individual projections. A variety of rib arrangements could be used.
[0030] The closure 10 is shaped and dimensioned to fit snugly within the open end of a poster tube, the or each rib 16 serving to maintain the tight fit. The product within the tube will therefore be well protected from the elements. The closure 10 in use locates entirely within the open end, or substantially so.
[0031] The fact that the upper surface 12 is planar and has no projecting parts itself ensures that, when positioned within the tube, e.g. by a sender, the closure 10 is flush with the tube's terminating end. This makes it very difficult for the closure 10 to be removed, e.g. inappropriately in transit, and the closure can be put in place by the sender without using tape, staples or other specialist apparatus.
[0032] To enable the end-user to remove the closure 10 , a breakable region 18 is provided in the closure 10 , as seen from the upper surface 12 . The breakable region 18 is formed by a line or boundary of weakness in the form of perforations or a score line which may or may not extend all the way through the closure's material. In the case of FIG. 2 , the breakable region 18 is defined within a circular score line 19 , which could alternatively be a perforation line, and enables the end-user to remove the closure 10 by using their finger or thumb to break part of the scored or perforated boundary, and then they pull the closure upwards from its lower surface.
[0033] Use of a score line instead of perforations is advantageous in terms of avoiding moisture entering the closed-off tube during storage or transit, which might damage its contents.
[0034] The breakable region 18 also serves as a visible indicator of tampering. The end user can see very clearly if the breakable region 18 is in any way damaged. The breakable region in some embodiments is within, and spaced from, the outer perimeter of the closure, without extending all the way to the outer wall. This makes it straightforward to manufacture, amongst other advantages. In some embodiments, there is no external projection from the closure (other than the downwardly extending peripheral wall) and in particular nothing projecting upwards or sidewards from the upper surface so that the closure can fit entirely within the open end of the tube with nothing projecting out of the tube when it is closed, which might otherwise get caught or tangled with other things when stored or during transportation.
[0035] In the case of the first embodiment, the shape of the closure 10 is circular. It can, however, be of any shape, e.g. square, rectangular, triangular and so on depending on the cross-sectional shape of the tube with which it will be used. Likewise, the shape of the breakable region 18 is in this case circular, but can be of any shape which is not dependent on the overall shape of the closure 10 .
[0036] FIG. 3 shows in cross-section the closure 10 when inserted within one-end of a tube 30 . The flush arrangement is visible, as is the use of the ribs 16 to provide a tight fit. The closure 10 can be provided as a separate item for use by poster suppliers, or a set of tubes and closures can be supplied in a kit or pack.
[0037] FIG. 4 shows a second embodiment closure 40 which is identical to the first shown in FIG. 2 , but is marked by printing, embossing or any similar means to indicate how to use the closure. The outer ‘ring’ 42 on the upper surface is indicated for the benefit of the person closing the tube 30 prior to sending, and ensures they do not accidentally break the inner breakable seal 44 . The breakable seal 44 is similarly marked to indicate how the end customer can access their product, and that damage to the seal indicates tampering which should alert them to contact the postal authorities or the sender.
[0038] FIG. 5 shows a third embodiment closure 50 , which employs a different shape and style of breakable seal region 54 within the outer part 52 . Specifically, the breakable seal 54 is a narrow rectangle with one narrow end not perforated and the other indicated as the preferred push point. This arrangement maximises the surface area which the packer uses to locate the closure 50 within the tube open end, and, because one end is not perforated, the broken region forms a tab rotatable about a fold line that prevents its removal and potential littering.
[0039] FIG. 6 shows a fourth embodiment closure 60 which in which a plurality of ribs 62 are provided on the external surface of the perimeter wall, extending vertically from a position between (but not necessarily from) the lowermost edge of the wall and the upper surface. The ribs 62 are distributed generally evenly around the perimeter wall, spaced apart from one another. The ribs 62 have a profile that tapers outwardly towards the upper surface to provide a wedge shape, as best seen with reference to the ribs on the opposite sides of the wall. The thickness of the ribs 62 at the point where they meet or reach the upper wall is arranged as to be the same, or just greater than, the internal diameter of a tube 30 (see FIG. 7 ) within which the closure 60 is to locate. This ensures that the closure 60 , when inserted, wedges firmly within the tube 30 at the point where the closure's upper surface and the upper edge of the tube are substantially flush, as shown in FIG. 7 . The closure 60 is prevented from moving further inside the tube 30 .
[0040] This arrangement of ribs 62 is applicable to any previous embodiment, i.e. instead of using horizontal ribs.
[0041] Otherwise, the features of the breakable region as previously described are present in the closure 60 .
[0042] In summary, there is described a poster closure system that locates snugly within the open end of a poster tube in a flush-arrangement, making it very difficult to grip and remove. The only realistic way of removing the closure is to break the breakable region, offering an immediate visual confirmation that the contents may have been tampered with.
[0043] It will be appreciated that the above described embodiments are purely illustrative and are not limiting on the scope of the invention. Other variations and modifications will be apparent to persons skilled in the art upon reading the present application.
[0044] Moreover, the disclosure of the present application should be understood to include any novel features or any novel combination of features either explicitly or implicitly disclosed herein or any generalization thereof and during the prosecution of the present application or of any application derived therefrom, new claims may be formulated to cover any such features and/or combination of such features.
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A poster tube closure includes a plug member for locating within an end of a poster tube. The plug member has a substantially planar closure surface with upper and lower faces, wherein a perimeter wall extends downwardly from the lower face for gripping the wall of a poster tube when inserted. The upper face has a frangible or weakened area arranged in use to be broken by user action to permit removal of the plug member and a visible indication of the breakage.
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FIELD OF THE INVENTION
This invention relates generally to wheelchairs and more particularly to a control means for automatically maintaining a wheelchair on a straight line course when traveling over uneven terrain.
BACKGROUND OF THE INVENTION
Most conventional power wheelchairs include left and right drive motors respectively connected to the left and right main wheels of the chair. A joy stick is provided as a control means, pivoting of the joy stick to the left causing the left motor to slow and the right motor to speed up and thereby turn the chair to the left. Pivoting of the joy stick to the right causes the right motor to slow and left motor to speed up to turn the chair to the right. Forward movement of the stick moves the chair forward at a speed generally proportional to the stick movement, ane rearward movement of the stick will reverse the motors to cause rearward movement of the chair.
It is desirable that the chair maintain a straight line course when the joy stick is in a centerline position; i.e., not tilted to the left or right. Normally, straight line tracking is accomplished by assuring that the left and right motors are turning at the exact same speeds. Maintaining identical speeds in turn can be accomplished by tachometer feedback circuits wherein an error signal is generated in response to any difference in the left and right motor rpm's and used to eliminate the difference.
While the foregoing controls will theoretically assure a straight line course for flat, even terrain, should there be any deviation of the terrain from a smooth flat surface, a turning of the wheelchair can result even though the main wheels are turning at the same rpm. For example, if a level surface changes to a surface sloping from the left side downwardly towards the right side, the right wheel will have to execute more rpm's than the left wheel while passing over the transition from the level surface to the sloping surface in order to keep the wheelchair on a straight course. It can be seen, accordingly, that simply maintaining identical speeds for the left and right wheels will not necessarily assure travel of the wheelchair in a straight line when the terrain is uneven.
BRIEF SUMMARY OF THE INVENTION
With the foregoing in mind, the present invention contemplates the provision of a wheelchair direction control means for maintaining the wheelchair on a straight line course notwithstanding the terrain may be uneven.
More particularly, in its broadest aspect, the control includes a caster wheel having a stem rotatably mounted on the wheelchair. This caster wheel engages the terrain over which the chair travels. Means are provided responsive to turning of the caster wheel stem as a result of turning of the wheelchair from a straight line course due to uneven terrain, connected to the power steering means for the chair to turn the chair back to its original straight line course.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of this invention will be had by referring to the accompanying drawings, in which:
FIG. 1 is a perspective view of a power wheelchair equipped with the direction control means of this invention, the wheelchair being shown traveling along a sidewalk towards a driveway;
FIG. 2 is a rear elevational view of the wheelchair looking in the direction of the arrow 2 of FIG. 1;
FIG. 3 is a view similar to FIG. 2 showing the wheelchair when traveling over a sloping surface constituting the entrance area of the driveway;
FIG. 4 is a side elevational view of a portion of the direction control means looking in the direction of the arrow 4 of FIG. 2; FIG. 5 is plan view of the control means shown in FIG. 4 taken in the direction of the arrows 5--5 of FIG. 2; and,
FIG. 6 is a simplified schematic diagram of one type of control means in accord with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1, there is shown a power wheelchair 10 having left and right main wheels 11 and 12 driven by left and right drive motors 13 and 14 respectively. As briefly described heretofore with respect to power wheelchairs, there is provided a joy stick 15 for controlling the steering, forward and reaward movement of the chair.
In accord with the present invention, there is provided a caster wheel 16 preferably positioned along a centerline C.L. midway between the left and right main wheels 13 and 14 for engaging the terrain over which the wheelchair 10 passes. While one of the front caster wheels already available on the wheelchair could be used and appropriately modified to carry out the present invention, it is preferable to provide a third caster wheel centrally positioned as shown.
In FIG. 1, the wheelchair 10 is shown on the surface A of a sidewalk. This sidewalk merges at B into a sloping surface C constituting the entrance of a driveway. The far side of the sloping surface C merges at D into a flat sidewalk surface again as at E.
The above described uneven terrain is typically found whenever a driveway crosses a sidewalk from the street and in the case of conventional wheelchairs, will result in a turning of the wheelchair outwards towards the street as indicated by the arrows in FIG. 1. This turning will take place even if means are provided for maintaining the speeds of the left and right wheels identical. The slope from left to right in FIG. 1 defines a longer path for the right wheel than the left wheel if the chair is to remain on a straight line course. Therefore, a slight speeding up of the right wheel relative to the left, or a slight slowing down of the left relative to the right is required to avoid the wheelchair following the turning path shown by the arrows. It will be understood that the change in relative speeds of the wheels is only necessary at the transition surfaces B and D. When the chair is on the flat surface A or E as in FIG. 2 or completely on the sloping surface C as in FIG. 3, it will stay on a straight line course so long as the wheels rotate at equal speeds.
FIG. 4 shows the caster wheel 16 from the side looking in the direction of the arrow 4 of FIG. 2. The caster wheel stem is shown at 17 and is vertically mounted by journal 18 to a frame portion 19 of the wheelchair. So long as the wheelchair is traveling in a straight line course, the caster wheel 16 and stem 17 will remain in a centered position. Any turning of the wheelchair independently of the manner in which the wheels rotate will result in a turning of the caster wheel 16 causing rotation of its stem 17 in the journal 18. By sensing this rotation a signal can be generated to turn the wheelchair back on to a straight line course. When this course is achieved, the caster wheel and stem will return to its centered position and the correcting signal will no longer be generated.
One type of sensing means for generating a control signal in response to turning of the caster wheel stem might constitute a simple potentiometer resistance and wiper arm. In FIGS. 4 and 5 such potentiometer resistance is shown at 20 secured in a fixed position as by mounting bracket 21 to the wheelchair. A wiper arm 22, in turn, is secured at one end to the upper end of the caster wheel stem 17 as at 23. The far end is free and makes electrical contact with potentiometer resistance 20.
FIG. 5 shows the caster wheel and wiper arm 22 in plan wherein it will be noted that turning of the caster wheel 16 to the phantom line position shown at 16' as a result of a turning of the wheelchair to the right will result in the wiper arm moving from its center position on the resistance to phantom line position 22'.
Referring to FIG. 6, one end of the potentiometer resistance 20 is grounded as at 24 and the other end connected at 25 to a positive voltage source; e.g. +15 volts. When the wiper arm 22 is in a centered position as shown, it will tap off 71/2 volts and this signal is passed via lead 26 to a first input of a differential amplifier 27. A reference voltage 28 is connected to the second input as shown. By making the reference voltage the same as the signal on lead 26 when the wiper is in a centered position, the inputs to the differential amplifier will be equal and there will be no output signal or "difference" signal. If the wiper arm moves off center to the left or right, there will then be generated an error signal at the output of the differential amplifier.
The above described error signal is utilized as a control signal and is passed via lead 29 to a control means 30. Control means 30 connects to the left and right drive motors 13 and 14 by way of leads 31 and 32 passing to first inputs of OR circuits 33 and 34 respectively. The second inputs of the OR circuits receive signals from a control means 35 operated by the joy stick 15 by way of leads 36 and 37.
The circuit of FIG. 6 is completed by provision of an appropriate means to disable the control means 30 when the joy stick 15 is intentionally moved to the left or right to steer the wheelchair. This means comprises cut-out switches 38 ganged for movement to an open position by the joy stick 15 as indicated by the dot-dashed line 39. Switch contacts for the switch arms 38 are shown at 40 and are elongated slightly so that a movement of the joy stick beyond a given degree is necessary to disconnect the control means 30 from the left and right motors.
OPERATION
The operation of this invention will be evident from the foregoing description. Referring to FIG. 1, with the caster wheel 16 attached to the chair as described, when the chair passes over the transition surface B, the resulting turning as described heretofore results in a turning of the caster wheel stem thereby immediately generating a signal from the differential amplifier 27. This signal will have a polarity determined by the direction of turning; i.e. to the right or left. The error or control signal will pass through the control means 30 and OR circuits to the left and right drive motors and will change the speed of one motor relative to the other in a manner to turn the wheelchair back to a straight line course. When a straight line course is reached, the caster wheel 16 returns to its centered position thereby reducing the feedback signal or control signal from the amplifier to zero.
It will be understood that the foregoing sequence is carried out very quickly and very little turning movement of the wheelchair actually occurs. In other words, the servo feedback loop functions with a rapid response time so that the wheelchair is maintained on its straight line course notwithstanding the uneven terrain.
When the chair reaches the far transition surface D, the resulting turning of the wheelchair will again be immediately corrected. Of course, if the patient wishes to intentionally turn the chair, he or she will utilize the joy stick in a conventional manner, the sensing circuit being cut-out as described. The sensing circuit thus operates only when the joy stick is substantially in its center position with respect to the left and right directions.
From all of the foregoing, it will now be evident that the present invention has provided a greatly improved wheelchair direction control means which not only eliminates the need for tachometer feedback type controls but performs better over uneven terrain.
Changes falling within the scope and spirit of this invention will occur to those skilled in the art. The direction control means is therefore not to be thought of as limited to the specific example set forth for illustrative purposes. For example, while the control signal has been illustrated as connecting to both the left and right drive motors to speed one up and slow one down in correcting a turn, it is possible to simply change the speed of at least one of the motors.
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A third caster wheel is mounted between the main wheels of a power wheelchair to engage the terrain over which the wheelchair travels. Turning of the wheelchair from a straight line course as a result of uneven terrain is immediately corrected by initially sensing the turning with the third caster wheel. A signal responsive to turning of the caster wheel stem is fed to the left and right wheelchair drive motors to increase the speed of one and decrease the speed of the other so as to return the wheelchair to its straight line course. The caster wheel sensing and feedback system is disabled when an intentional turning of the wheelchair is carried out with the conventional joy stick.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is a method and apparatus for updating computer program code stored in nonvolatile memory, in a way that that reduces the chance of corrupting the part of the code used for initialization.
2. Description of Related Art
Referring to FIG. 1 , a unit that contains a general processor, such as a computer system 106 or an adapter 100 , requires code to initialize (boot). Because the processor 114 or 130 in such a unit must be able to access boot code 116 using basic hardware access, the boot code 116 must be stored in nonvolatile memory 118 . Nonvolatile memory, includes, but is not limited to, Read-Only Memory (ROM), Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Flash memory, and the like. Flash memory is the nonvolatile memory of choice in many modern applications. However, unlike conventional RAM, whose data can be simply read or written, flash memory is setup to be read-only during normal operations and requires special procedures to be written.
In the example of an adapter, when a unit is booted, the processor 114 is directed to a particular address in the nonvolatile memory 118 , where it begins executing boot code 116 in boot region 122 . It is important that this boot code 116 run correctly, otherwise the unit 100 will not initialize correctly and basic operations will fail. Moreover, a host computer system 106 containing this unit may in turn fail to boot. For example, if the boot operations fail in a device located in the host computer system 106 , the entire computer system may fail to boot. Thus, care is required in updating the boot code.
Although the above discussion describes how the processor 114 in a unit 100 such as a HBA (Host Bus Adapter) uses nonvolatile memory for initialization, the processor 130 in the host computer system 106 also utilizes nonvolatile memory in a similar fashion. For reliability, the nonvolatile memory of the host computer system 106 may similarly be divided into boot code and application code. The boot code is executed when the host computer system 106 is first turned on to initialize the host computer system 106 , and the application code is run in order to read a mass storage device, such as a disk drive. Then the operating system code that is stored on the disk can be loaded and run. One program that is typically stored in nonvolatile memory of a host computer is the Basic Input/Output System (BIOS).
In order to support new technology or to correct problems, it may become necessary or desirable to update the code in nonvolatile memory. If the nonvolatile memory is flash memory, then a program can be run in situ to update the BIOS used by the host computer or to update the code stored in an adapter. This saves the expense of removing the nonvolatile memory from the unit and updating it with specialized equipment, usually at the manufacturer's site.
When a program is used to update nonvolatile memory, care must be taken to handle the varied environments at customer sites. For example, with some flash memory, an entire block of memory must be erased before writing can commence. If the erase operation is successful, then write operations can proceed, often one byte at a time. Once a block is erased, it cannot be reverted and a new block of code must be successfully written in its place. As each byte is written, it should be checked to verify that the code was written correctly. If a problem is detected, the write operation may be re-tried several times. Once an entire block is written, the entire block may be verified byte-by-byte. A checksum or a cyclic redundancy check (CRC) may also be performed to validate the code being written.
On occasion, problems with updating nonvolatile memory can arise. For example, loss of power would prematurely terminate update operations. If an adapter was reset while being updated, the bus mapping of the adapter could change and writes to the nonvolatile memory could fail. Another source of problems is PCI bus version incompatibility. For example, when updating an adapter in a host system that is not PCI 2.1 compliant, the REQ64 and ACK64 bus signals may be left floating. As a result, incorrect addresses may be used in updating the adapter's nonvolatile memory and the code written to nonvolatile memory can be corrupted.
If the boot code is corrupted but the unit is currently using the application code, the unit will not immediately be affected by the error. However, the error will cause problems the next time the boot code is utilized, at the next power-up or when the unit is reset. For example, in the case of corrupt boot code in an adapter attached to the PCI bus of a host computer, when the host computer is powered up, its BIOS will identify and communicate with every adapter in its PCI bus. If an adapter fails its boot operations, either the adapter will be skipped by the host system or it may cause the host system's BIOS to fail. Because the host computer cannot identify or communicate with the adapter, it cannot update the nonvolatile memory in the adapter. Thus, the only recourse at that time is to send the adapter back to the manufacturer.
To avoid corruption of the nonvolatile memory, some units divide the nonvolatile memory code into regions so that each update-code file contains just one region such as the boot code region or the application code region, or combinations thereof. With multiple update files, a user can pick and choose which regions of memory to update without having to update the entire nonvolatile memory. In addition, the user may be prohibited from updating certain areas of memory. For example, only the application firmware might be placed in an update-code file and made available to a user. If the user performs an update with that update-code file, only the application region would be updated, leaving the boot region intact. Without this fragmentation and restriction of the update-code files, a user believing that “more is better” may choose to update all the regions or unnecessary regions, increasing the likelihood of updating errors. Other manufacturers suggest avoiding updating the boot code in their documentation.
In any case, because the image file selection process is manually performed, if the user is given a menu of available image files for updating, there is no mechanism for preventing a user from updating vital regions that do not need updating. Even when it is necessary to update the boot code region, current solutions do not first test the ability to write in a non-vital region, nor do they warn the user that an update is unnecessary or regressive.
Thus, a need exists for an apparatus and method for updating nonvolatile memory that warns the user that an update is unnecessary or regressive, and also tests the ability to write in a non-vital region prior to updating a vital region.
SUMMARY OF THE INVENTION
Processors such as those found in an adapter typically access nonvolatile memory such as flash memory for executing initialization routines (boot code) stored in the boot region of the nonvolatile memory, upon power-up or re-boot, and also for copying application code stored in the application region of the nonvolatile memory (which is used to perform product-specific functions). At times, it may be desirable or necessary to update this code (firmware) stored in the nonvolatile memory. However, if incorrect or corrupted code is written to the boot region of nonvolatile memory, it may not be possible to correct this code.
To avoid the possibility of such corruption, embodiments of the present invention determine if an attempted update to a vital region (e.g. the boot region) of the nonvolatile memory is unnecessary or regressive. This is done by reading and comparing the version number of the code stored in the vital region to the version number of the new (update) code prior to performing the update. The invention also tests the ability to update/write to the nonvolatile memory prior to actually updating the vital region by first performing and verifying a “write test” operation in a less vital region (e.g. a test region).
The first step that may be performed before updating the vital region of nonvolatile memory is “version checking.” In version checking, the version of the existing code in the vital region is compared to the update code. If the versions match, or if the existing version is more recent than the update code, then the update is not performed, thereby avoiding unnecessary updates and minimizing the chance of a write error.
If the version comparison indicates that an update is appropriate, then the next step is to perform a test by initializing (unlocking and erasing) a block in a less vital region and performing a write test operation to that block. During initialization, an erase command is issued to the block, and an attempt is made to verify that the erase command was successful. If the erase command was unsuccessful, the erase command may be re-tried a few times before the update program terminates. If the erase command was successful, then a write test is done to the erased block. Both the status of the write command and a verification of the data are checked to see if the write was successful. If the write command was unsuccessful the write test command may be re-tried a few times before the update terminates. Once an entire block in the less vital region has been erased, written and verified, the update to the vital regions can proceed. Optionally, prior to performing the actual write operation, the write test could be extended to multiple blocks to more closely simulate an actual update. In this embodiment, multiple blocks in the less vital region may be erased one block at a time, and may be written and verified one byte at a time, before the actual write operation is initiated.
The nonvolatile memory may contain an application region and, provided there is enough free space available, a test region. Both the application region and test region are less vital regions as compared to the boot region. In embodiments of the present invention, the operations of initializing and writing described above are preferably performed in the test region. If the write test operation to the test region fails, both the boot region and application regions are still intact and the unit can function with the old code. If the write test operation is successful, then an update is performed in the boot region and application region as necessary.
If a test region is not available, the operations of initializing and writing may be performed in the application region. If the write test operation to the application region fails, the boot region is still intact and the unit can boot with the old code to allow the application region to be correctly rewritten. If the write test operation is successful, then the boot region and application updates can proceed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exemplary block diagram illustrating a system environment comprising a host computer containing a unit such as a host bus adapter (HBA).
FIG. 2 illustrates an exemplary arrangement of a nonvolatile memory into boot, application and test regions according to embodiments of the present invention.
FIG. 3 is an exemplary flow chart of an update or flash program for updating nonvolatile memory according to embodiments of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the following description of preferred embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustrating specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the preferred embodiments of the present invention.
It should also be noted that although embodiments of the present invention are primarily described herein in terms of updating the boot region of nonvolatile memory in HBAs for purposes of illustration and discussion only, embodiments of the present invention are applicable to updates of any region in nonvolatile memory, such as the application region, and to other hardware (e.g. personal computers (PCs) or other computing devices) containing processors that must be booted from nonvolatile memory, and most generally to any situation in which nonvolatile memory must be updated.
HBA processors typically access nonvolatile memory such as flash memory for executing initialization routines (e.g. boot code) in vital boot regions of the nonvolatile memory upon power-up or re-booting, and for copying or executing application code stored in application regions of the nonvolatile memory for performing the HBA's intended function. At times, it may be desirable or necessary to update this code (firmware) stored in the nonvolatile memory. However, if incorrect or corrupted data is written to the boot region of nonvolatile memory, the HBA may not initialize properly and it may not be possible to correct the corrupted data. If this HBA is a PCI card in a host computer, the corruption may cause the host computer to hang up upon power-up or re-boot, or may cause the host computer to fail to identify the HBA. An HBA corrupted in this way would no longer be usable by a customer and would have to be returned to the vendor.
To avoid the possibility of such corruption, embodiments of the present invention determine if an attempted update of the nonvolatile memory is unnecessary or regressive. This is done by reading and comparing the region's version number to the update code's version number prior to performing the update. In addition, the invention also tests the ability to update/write to the nonvolatile memory prior to actually updating the vital region by first performing and verifying a “write test” operation in a less vital region (e.g. a test region). The present invention may reside in an update or flash program that is executed when an update to the nonvolatile memory is desired. This invention is applicable to a variety of host computers or processors embedded in adapters such as HBAs.
The write test operation is intended to help users prevent corruption to the vital nonvolatile memory of HBAs or processors when updating code in the boot region is inadvertently attempted in a physically defective system or an environment that does not meet requirements.
FIG. 2 illustrates an exemplary arrangement of a nonvolatile memory divided into boot region 200 , application region 202 , and test region 204 according to embodiments of the present invention, although the test region 204 is optional. As defined herein, the boot region is a more vital region than the application and test regions, and the application region is a more vital region than the test region. A version number ( 206 , 208 ) is maintained in each of the boot and application regions so that each region can be checked individually before that region is updated. Note that the version number may optionally be followed by a checksum, date information, and the like.
FIG. 3 is an exemplary flow diagram of a program for updating nonvolatile memory according to embodiments of the present invention. The update program can be executed from the host computer with code sent across the PCI bus to update nonvolatile memory in the HBA, or it can be run in firmware within the HBA to update the nonvolatile memory in the HBA.
The first step that is performed before updating a particular region in the nonvolatile memory is version checking. This version checking step, although illustrated in FIG. 3 , is optional and may be omitted. At step 300 , the version of the existing code in the region of nonvolatile memory to be updated is compared to the update code. If the versions match, or if the existing (memory) version is more recent than the update (image) version, then the update is not performed (see 302 ), thereby avoiding unnecessary updates and minimizing the chance of a write error. In one embodiment, the version number includes both major and minor revision levels (e.g. v2.1), and both are checked against what is contained in the update file.
In one embodiment of the present invention, when the update program is executed, the display for the host computer may indicate the current version number of the boot code stored in the nonvolatile memory of the HBA, and the version number of the update file. In one embodiment, the display may query the user as to whether the update program should proceed. In another embodiment, if the versions are identical, the update program may automatically terminate. The update program may also perform a CRC on the contents of the nonvolatile memory and on the update file prior to updating to ensure that they are still valid, and the outcome of the CRC may be displayed to the user.
If the version comparison indicates that an update to a vital region is appropriate, then the next step is to perform a write test by initializing (unlocking and erasing) and performing a write test to a block in a less vital region at 304 . However, before the write test is performed, the memory type is identified so that the appropriate commands (e.g. read, write, erase) and sequences can be sent. To identify the memory type, an identifier command may be issued to the nonvolatile memory by the update program, and the nonvolatile memory will respond with an identifier. Once the memory type is known, the update program may utilize a table listing various types and sizes of nonvolatile memory supported by the update program to determine the appropriate commands to be sent. The addresses for the write test operation are established and the block boundaries are identified (because certain operations take place on these boundaries). Depending on the memory type, it may be necessary to unlock each block to be erased and re-written (and then lock each block at the end so that it can only be read). An erase command is then issued to a single block and verified. If unsuccessful, the erase command may be re-tried a few times, but if the erase continues to be unsuccessful, the update program may terminate. If the erase command is successful, then one byte may be written. The byte is then verified at step 306 by checking it against the update file (i.e. a verification of test status and data). If the write is unsuccessful, the write test command may be re-tried a few times, but if the write continues to be unsuccessful, the update program may provide status information and terminate. This process of writing and verifying one byte at a time continues for the rest of the block, then other blocks are erased one block at a time, and then written and verified one byte at a time. Note, however, that in other embodiments, the erase and write sizes could be different. In other embodiments, it may also be possible to verify the written data by reading back entire words or blocks at a time to speed the operation.
As described above, the nonvolatile memory contains an application region and, provided there is enough free space available, a test region. In embodiments of the present invention, the operations of initializing and writing described above are preferably performed in the test region. If the test region is utilized, then the update file intended for the boot region could be written into the test region, or any other test file could be written. If the write test operation to the test region fails, the update program may report an error status and terminate at 308 . However, because the firmware in the boot and application regions of the non-volatile memory was preserved, the adapter is left in an entirely functional state. The adapter may then be taken to a known working environment and updated there.
If a test region is not available, the operations of initializing and writing may be performed in the application region. If the write test operation to the application region fails, the boot region of the adapter is left intact and bootable. The application firmware could then be restored by taking the device to a known working environment and updated there. In other words, although the card will not operate as an iSCSI or fibre channel HBA, for example, the device will still be able to identify itself correctly to the host computer and set up the PCI interface so that the host computer can still communicate with the device at a basic level. If the write test operation is successful, then the update is performed at 310 .
Although the present invention has been fully described in connection with embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the present invention as defined by the appended claims.
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A method for avoiding the possibility of corruption when updating vital code such as boot code stored in nonvolatile memory of a unit, such as a host bus adapter, or adapter circuitry integrated onto a motherboard, or a computer system, is disclosed. Prior to updating the vital code, the method determines if the attempted update is unnecessary or regressive by reading and comparing the region version number in nonvolatile memory to the version number in the update code. If the update is unnecessary, the user is alerted. In addition, the method tests the ability to update/write to the nonvolatile memory by performing a write test operation to a less vital region prior to updating the vital region. The less vital region may comprise a test region set aside in the nonvolatile memory for performing write tests, or it may be an application region reserved for storing application programs.
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CROSS REFERENCE TO RELATED APPLICATIONS
This patent application claims the benefit of U.S. provisional patent application filed on Jul. 29, 2014 and assigned Application No. 62/030,260, incorporated herein in its entirety.
FIELD OF THE INVENTION
A method, system, and kit related to a removable and replaceable barrel and gas tube for modular rifles.
BACKGROUND OF THE INVENTION
M16 and AR15 rifles are air-cooled, gas-operated, magazine-fed assault rifles. These rifles are the primary assault weapons used by military and police forces.
A gas-operated rifle uses a portion of the high pressure gas formed as the ammunition round travels through the barrel to supply energy to operate the auto-loading feature of the rifle. The high pressure gas powers a mechanism to extract the spent casing and chamber a new cartridge. Energy from the gas is harnessed through either a port in the barrel or a trap in the muzzle. This high-pressure gas travels through a gas tube that is located parallel to the barrel and upon exiting the tube impinges on a surface such as a piston head to provide motion for unlocking the action, extracting the spent casing, ejecting the spent casing, cocking the hammer or striker, chambering a fresh cartridge, and finally locking the action.
Such a modular rifle is illustrated in FIG. 1 . As shown in FIG. 2 , the rifle comprises a lower receiver assembly 1 conveniently separable from an upper receiver assembly 2 . The lower and upper receiver assemblies 1 and 2 are connected using push pins with the pins carried by the lower receiver assembly 1 and extending through openings (not visible in FIG. 2 ) in the upper receiver assembly 2 .
The lower receiver assembly 1 contains a lower receiver, fire control components, and a buffer assembly included in the butt-stock. These components are not separately designated in FIG. 2 and are not pertinent to the structure and function of the present invention. Instead, the present invention relates generally to the upper receiver assembly 2 and its components.
Prior art FIG. 3 illustrates the upper receiver assembly 2 , comprising an upper receiver 3 and a hand guard 4 surrounding a barrel 5 . The barrel 5 is affixed to the upper receiver 3 using a barrel nut that is obscured from view in FIG. 3 but shown in FIG. 4 .
Prior art FIG. 4 illustrates the upper receiver assembly 2 with the hand guard 4 removed to expose a barrel nut 6 , a stock gas tube 7 and a gas block 8 that holds the stock gas tube 7 in place. The barrel 5 and the gas block 8 each define a small opening through which gas passes from the barrel, through the gas block, and into the stock gas tube 7 .
In the prior art modular rifles of FIGS. 1-4 , the barrel 5 is affixed to the upper receiver 3 with the barrel nut 6 and this arrangement requires specialized tools and fixtures to remove and attach the barrel. For example, if the user wishes to change to a barrel of a different length. The prior art design makes it nearly impossible to remove the barrel in the field without use of these tools. Removal also requires a significant amount of time and familiarity with intricate mechanisms of the rifle.
BRIEF DESCRIPTION OF THE FIGURES
The forgoing and other features of the present invention will be apparent to one skilled in the art to which the present invention relates upon consideration of the description of the invention with reference to the accompanying drawings. The use of the same reference numeral in the various figures refers to the same element.
FIG. 1 illustrates an exemplary prior art AR15/AR10 modular rifle.
FIG. 2 illustrates an exploded view of the prior art AR15/AR10 modular rifle of FIG. 1 .
FIGS. 3 and 4 illustrate components of the prior art upper receiver assembly of FIG. 2 .
FIG. 5 illustrates an exploded view of components of a upper receiver coupler and a barrel coupler.
FIG. 6 illustrates the upper receiver and FIG. 7 the upper receiver with the upper receiver coupler attached thereto.
FIG. 8 illustrates the upper receiver coupler.
FIG. 9 illustrates the barrel coupler and the attached barrel.
FIG. 10 illustrates the barrel coupler.
FIGS. 11 and 12 illustrate the barrel with different length gas tubes.
FIG. 13 illustrates the barrel coupler, the barrel, and the hand guard.
FIG. 14 illustrates an exploded view of the upper receiver coupler (attached to the upper receiver) and the barrel coupler (attached to the barrel and hand guard).
FIG. 15 illustrates the barrel coupler mated to the upper receiver coupler.
FIG. 16 illustrates the barrel coupler attached to the upper receiver coupler.
FIG. 17 illustrates an AR15/AR10 rifle with the components of the present invention attached thereto.
FIG. 18 illustrates another embodiment of the barrel coupler and upper receiver coupler.
FIGS. 19-21 illustrate three different gas tubes.
FIGS. 22 and 23 illustrate different views of details of the hook and lever of the barrel coupler.
FIG. 24 illustrates an alternative embodiment of the upper receiver coupler.
DETAILED DESCRIPTION OF THE INVENTION
Before describing in detail the particular methods and apparatuses related to a removable barrel and hand guard for modular rifles, it should be observed that the present invention resides primarily in a novel and non-obvious combination of elements and process steps. So as not to obscure the disclosure with details that will be readily apparent to those skilled in the art, certain conventional elements and steps have been presented with lesser detail, while the drawings and the specification describe in greater detail other elements and steps pertinent to understanding the inventions.
The presented embodiments are not intended to define limits as to the structures, elements or methods of the inventions, but only to provide exemplary constructions. The embodiments are permissive rather than mandatory and illustrative rather than exhaustive.
The components of the present invention when installed in a rifle allow the rifle user to easily and quickly remove the barrel without specialized tools and replace the removed barrel with a barrel of a different length. As is known by those skilled in the art, a longer barrel allows the ammunition round to exit the barrel with a greater velocity and thus travel farther (i.e., have a longer range) than a round shot from a shorter barrel.
Advantages of the present invention include at least: allowing the rifle barrel to be easily removed to store or transport the rifle in a smaller space; allowing the user to easily remove and replace the barrel with a different length barrel; allowing conversion of the rifle to a different caliber; and, simplifying cleaning of the weapon as specialized tools are not required to disassemble the rifle. With regard to different barrel lengths, a sniper prefers a longer rifle barrel while a shorter barrel is desired in close quarter combat.
The invention also permits the user to use any one of many different available hand guards. Alternatively, the barrel coupler of the present invention may be supplied with a hand guard permanently integrated with the barrel coupler. In this latter embodiment the barrel and hand guard can both be removed from the rifle as one unit without the user of tools.
The components of the present invention may be installed on any rifle or weapon having an appropriately styled barrel and receiver interface.
The components of the invention may also be considered a kit for adding and/or replacing the components of an existing rifle to allow the user to then easily and conveniently exchange a barrel of a first length for a barrel of a second length. The kit components can be installed on an existing rifle without any permanent modifications to the rifle. Alternatively, certain of the invention components can be integrated into a new rifle as it is manufactured, e.g., the upper receiver coupler integral with the upper receiver and/or the barrel coupler integral with the barrel.
The components of the invention generally comprise: an upper receiver coupler for attaching to an upper receiver of an existing rifle and a barrel coupler for attaching to a barrel of the existing rifle. The upper receiver coupler and the barrel coupler are removably joined or latched together using components attached to the upper receiver coupler, to the barrel coupler, and/or to both. Further, the invention comprises a novel gas tube that is attached to the barrel, passes through the upper receiver coupler and the barrel coupler, and via a gas tube extension attaches to the rifle upper receiver.
FIG. 5 is an exploded view illustrating an upper receiver coupler 100 and a barrel coupler 103 and their associated components. With the upper receiver coupler attached to the upper receiver, as described elsewhere herein, and the barrel coupler attached to the barrel, as described elsewhere herein, coupling the upper receiver coupler and the barrel coupler thereby attaches the barrel to the upper receiver to form a continuous path for the ammunition round.
Additionally, when the upper receiver coupler and the barrel coupler are joined, a gas tube running parallel to the barrel extends from a forward end of the barrel, passes through both couplers, and is received within the upper receiver of the rifle. Gas flowing through this path actuates various rifle functions as described above.
Turing to FIG. 6 , it illustrates the conventional upper receiver 3 further comprising a threaded upper receiver extension 3 A and a gas port 3 B. In a prior art rifle, the barrel is received within the upper receiver extension 3 A and a barrel nut (not shown) holds the barrel within the upper receiver extension. A groove 3 C receives a tab on the barrel (not shown) to properly align the barrel to the upper receiver.
With reference to FIGS. 5, 6, and 7 , to attach the upper receiver coupler 100 to the upper receiver 3 , the threaded upper receiver extension 3 A is inserted into an opening 10 A defined in an upper receiver plate 10 . Internal threads 11 A of a star nut 11 threadably engage external threads of the upper receiver extension 3 A, and the star nut 11 is tightened to fixedly join the upper receiver coupler 100 to the upper receiver 3 . FIG. 7 illustrates the final configuration.
Semicircular grooves 16 in an outer circumference of the star nut 11 receive mating protrusions of a tool (not shown) for tightening the star nut 11 . However, this feature is not a required element of the invention instead it is merely a convenient technique for tightening the star nut 11 .
FIG. 8 also illustrates certain components and features of the upper receiver coupler 100 including the upper receiver plate 10 and the star nut 11 . The remainder of the illustrated components are described below.
In an alternative embodiment, in lieu of using the star nut 11 , the upper receiver plate 10 comprises internal threads 25 (see FIG. 24 ) that threadably engage mating threads 3 D on the upper receiver extension 3 A of FIG. 6 .
With reference to FIGS. 5 and 9 , to position the barrel 5 within the barrel coupler 103 , the barrel is received within an opening 103 A that extends through the barrel coupler. A raised segment of the barrel, referred to as a collar (see a collar 5 A in FIGS. 9, 11, and 12 ), is disposed within the opening 103 A and a rear surface of the collar 5 A abuts an internal surface of the barrel coupler 103 .
With continued reference to FIGS. 5 and 9 , set screws 17 distributed around a circumference of a barrel plate 14 are urged against the barrel 5 to hold the barrel within the barrel coupler 103 . In one embodiment the set screws are spaced at 120 degrees although only one set screw 17 is illustrated in FIG. 5 . Additionally, when the barrel coupler and the upper receiver coupler are mated, the barrel flange is captured and held in place between the mated barrel coupler and the upper receiver coupler. Also, in one embodiment the groove 3 C of the upper receiver extension 3 A of FIG. 6 receives a tab (not shown) of the barrel to align the barrel in the upper receiver. Finally, the mated couplers exert additional forces on the barrel to secure the barrel within the barrel coupler.
As can be seen in FIG. 9 , a barrel segment 5 B of the barrel 5 extends beyond a rear surface of the barrel coupler 103 . The barrel segment 5 B extends into the opening 10 A (see FIGS. 5, 7, and 8 ) of the coupler plate 10 when the upper receiver coupler and the barrel coupler are mated.
In lieu of using the set screws 17 , the barrel can be held in place within the barrel coupler 103 by a compression fitting comprising a slot defined in the barrel plate 14 and a tension screw to close the slot after the barrel is inserted. Alternatively, an end of the barrel comprises a split cone feature with an outside-threaded nut for threading into mating threads extending from a rear surface of the barrel plate.
Returning to FIG. 5 , in addition to the barrel plate 14 , the barrel coupler 103 further comprises hooks 12 , levers 13 for operating the hooks 12 , and a barrel plate extension 14 A. Only one hook 12 and lever 13 is illustrated in FIG. 5 as the opposing hook and lever is not visible in FIG. 5 .
The hooks 12 and levers 13 are held together by pins not illustrated in FIG. 5 but depicted as a pin 140 in FIGS. 22 and 23 . With reference to FIG. 5 , the pin is held in position by a set screw 22 , again, with only one illustrated in FIG. 5 .
With the barrel coupler 103 in contact with the upper receiver coupler 100 , exerting an inwardly-directed force on the levers 13 forces the hooks 12 to each engage a hardened pin 21 within each recess 10 B in the upper receiver plate 10 . This action locks the barrel plate 14 to the receiver plate 10 and thereby locks the barrel coupler 103 to the upper receiver coupler 100 . Another hook, lever, recess and pin are disposed on an opposing side of the respective barrel plate and the upper receiver plate and thus are hidden from view in FIG. 5 .
The illustrated pin 21 is held in position by action of a set screw 23 .
With the barrel 5 attached to the barrel coupler 103 with the set screws 17 , the barrel coupler 103 attached to the upper receiver coupler 100 with the hooks 12 , and the upper receiver coupler attached to the upper receiver 3 with the star nut 11 , the barrel is thereby coupled to upper receiver to provide a path for the round as it exits the upper receiver, enters and passes through the barrel segment 5 B (see FIG. 9 ) and the barrel 5 , and exits from a forward end of the barrel 5 .
With this invention the barrel 5 can be easily and quickly changed by operating the levers 13 to release the hooks 12 and thereby separate the upper receiver coupler 100 from the barrel coupler 103 and loosening the set screws 17 . This operation is much simpler than the required operations to remove the barrel in a prior art rifle.
With reference to FIG. 5 , when the barrel coupler 103 is brought into contact with the upper receiver coupler 100 , an alignment pin 19 extending rearward from a rear surface of the barrel plate 14 is received within an opening 20 in a front surface of the upper receiver plate 10 for aligning the upper receiver coupler 100 and the barrel coupler 103 .
FIG. 10 is a rear view of the barrel coupler 103 . In particular, this view shows an opening 29 through which a primary gas tube 33 passes, as described below.
As described above, a gas-operated rifle uses some of the high pressure gas generated as the ammunition round travels through the barrel to supply energy to operate the auto-loading feature of the rifle. In the present invention, a high pressure gas path extends from an entry point of the gas tube on the barrel 5 , along the barrel, through the barrel coupler 103 , through the upper receiver coupler 100 and finally to the upper receiver 3 .
As can be seen in FIGS. 5 and 9 , a primary gas tube 33 extends forward from the barrel plate 14 runs parallel to the barrel 5 and connects to the barrel 5 at the gas block 8 .
Working toward the butt stock of the rifle and beginning at the barrel plate 14 , the primary gas tube 33 passes through the opening 29 (see FIG. 10 ) in the barrel plate 14 . A rearward segment 33 A of the primary gas tube 33 (see FIGS. 5 and 9 ) extends rearward out from the opening 29 in the barrel plate and through an opening 36 (see FIG. 8 ) in the receiver plate 10 . An end 33 B of the rearward segment 33 A mates with a coupler 34 (that is, when the upper receiver coupler 100 and the barrel coupler 103 are coupled) that is in turn connected to a gas tube extension 35 (see FIGS. 5 and 8 ).
To avoid interference between the rearward segment 33 A of the primary gas tube 33 and the upper receiver coupler 100 and its associated components, the rearward segment 33 A is disposed within one of the semicircular grooves 16 of the star nut 11 .
An end 35 A of the gas tube extension 35 (both of which are depicted in FIG. 5 ) is received within the gas port 3 B of the upper receiver 3 as illustrated in FIG. 6 .
FIG. 11 illustrates the barrel 5 with a stock or stock gas tube 7 installed in the gas block 8 .
FIG. 12 illustrates the barrel 5 with the shortened primary gas tube 33 , i.e., shorter than the stock gas tube 7 , installed in the gas block 8 . The shortened gas tube is required due to presence of the receiver coupler 100 and the barrel coupler 103 in the gas flow path between the gas block 8 and the gas port 3 B in the upper receiver 3 .
FIG. 13 illustrates the hand guard 4 as mated with the barrel coupler 103 and covering a segment of the barrel 5 and the entire length of the primary gas tube 33 . To attach the hand guard 4 , inside threads of the hand guard threadably engage outside matching threads of the barrel plate extension 14 A depicted at least in FIGS. 5 and 9 .
FIG. 13 also reveals that the hand guard 4 and the barrel 5 , when affixed to the barrel coupler 103 , can be removed from the rifle as a unitary structure by simply separating the barrel coupler 103 from the upper receiver coupler 100 .
FIG. 14 illustrates the upper receiver coupler 100 (and certain ones of its attached components) in position to mate with the barrel coupler 103 (and certain ones of its attached components).
To mate the upper receiver coupler 100 and the barrel coupler 103 , (see FIGS. 5 and 14 in particular) the opening 10 A in the upper receiver plate 10 is aligned with the barrel segment 5 B, the pin 19 of the barrel coupler is aligned with the opening 20 in the receiver coupler, and the rearward segment 33 A of the gas tube is aligned with the coupler 34 . The upper receiver coupler and the barrel coupler are brought into contact and by the application of an inwardly directed force on the levers 13 , the hooks 12 on the barrel coupler are locked around the pins 21 in the recesses 10 B of the upper receiver coupler.
FIG. 15 illustrates the mated upper receiver coupler 100 and the barrel coupler 103 with the hooks 12 in an open position.
FIG. 16 illustrates the coupled upper receiver coupler 100 and the barrel coupler 103 with the hooks 12 in a closed position.
FIG. 17 illustrates an AR15/AR10 110 depicting the upper receiver coupler 100 and the barrel coupler 103 of the present invention.
FIG. 18 illustrates another embodiment of the present invention comprising an upper receiver coupler 111 for mating with a barrel coupler 113 . The upper receiver coupler 111 defines recesses 120 each for receiving a hook 122 (in lieu of the hook 12 of other embodiments) to attach the upper receiver coupler 111 to the barrel coupler 113 .
Each hook 122 comprises a head 130 affixed to a shaft 132 at a first end thereof. A second end of the shaft 132 terminates in a ring 133 concentrically mounted on a pin 136 that is in turn attached to or captured within a barrel plate 137 . The hooks 122 are pivoted into the recesses 120 to lock the upper receiver coupler 111 and the barrel coupler 113 together.
Pivoting of the hooks 122 out of the recesses 120 permits separation of the upper receiver coupler 111 and the barrel coupler 113 . Only one of the hooks 122 is depicted in its entirety in FIG. 18 , another hook 122 and its associated components is hidden from view in FIG. 18 .
In one embodiment the head 130 threadably engages mating threads (not shown) on the shaft 132 . The coupling force exerted by the hook 122 on the upper receiver coupler 111 is adjusted by turning the head 130 on the mating threads of the shaft 132 .
FIG. 19 illustrates a stock gas tube 7 . FIG. 20 illustrates the shortened primary gas tube 33 connected to the gas tube extension 35 for use with the couplers of the present invention. FIG. 21 illustrates an exploded view of the primary gas tube 33 and the gas tube extension 35 .
FIG. 22 is a close-up view of the hook 12 and the lever 13 including a pivot pin 140 and a tension adjustment screw 142 . Turning the screw 142 adjusts (increasing or decreasing) the force exerted by the hook 12 for holding the upper receiver coupler 100 and the barrel coupler 103 together and for increasing or decreasing the distance between the two couplers.
FIG. 23 depicts the hook 12 , the pivot pin 140 and the tension adjustment screw 142 .
Because the components of the present invention can be added to an existing rifle without modifying the existing rifle, these components can be easily removed and the rifle returned to its original configuration whenever desired. This is an advantage to the rifle owner who may wish to sell or trade-in a rifle that has been modified to implement the features of the present invention.
While the invention has been described with reference to various embodiments, it will be understood by those skilled in the art that various changes may be made and equivalent elements and process steps may be substituted for elements and steps thereof without departing from the scope of the present invention. The scope of the present invention further includes any combination of the elements and process steps from the various embodiments set forth herein. In addition, modifications may be made to adapt a particular situation to the teachings of the present invention without departing from its essential scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
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A kit for use with a modular weapon having a barrel and having an upper receiver defining a gas port and a barrel opening. The kit comprises an upper receiver plate for attaching to the upper receiver, and a barrel plate. The weapon barrel passes though concentric openings in the upper receiver plate and the barrel plate and is secured in the opening within the barrel plate. Another opening in the barrel plate receives a primary gas tube such that a rearward segment of the primary gas tube extends rearwardly from that opening and a forward segment of the primary gas tube extends forwardly from that opening. A forward end of a gas tube extension couples to a rearward end of the primary gas tube and a rearward end of the gas tube extension is received within the gas port when the kit is in use with the modular rifle. An assembly removably attaches the upper receiver plate and the barrel plate thereby creating a gas flow path beginning at the gas port and comprising the gas tube extension, the rearward segment of the primary gas tube, and the forward segment of the primary gas tube.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a magnetic random access memory or MRAM and a method for manufacturing such a memory.
2. Discussion of the Related Art
FIG. 1 illustrates the operation of a magnetic RAM. Such a memory comprises an array of memory elements arranged in rows and in columns, a single memory element 10 being shown in FIG. 1 . Each memory element 10 is formed of the stacking of three layers: a first layer 12 formed of a magnetic material, for example, cobalt, having a fixed magnetic orientation, a second layer 14 formed of an insulator, and a third layer 16 formed of a ferromagnetic material, for example, cobalt and iron alloy or a nickel and iron alloy, the magnetic orientation of which can vary. Insulating layer 12 behaves as a barrier to prevent the alloying between magnetic layer 12 and ferromagnetic layer 16 and enable the passing of electrons, the spin of which must be kept. Generally, each layer of the memory element may itself be formed of several layers. All the memory elements 10 of a same array column are connected to a conductive track 18 , behaving as a bit line. A conductive track 20 is arranged above the memory elements 10 of a same array row but is not in electric contact with the memory elements of the row.
For each memory element 10 in the array, first layer 12 is connected via a portion 22 of connection to the drain (or to the source) of an N- or P-channel MOS transistor 24 having its source (or its drain) connected to a reference voltage, for example, ground GND. The gate of MOS transistor 24 is controlled by a gate control signal S G . The MOS transistor associated with each memory element may be replaced with a diode circuit. MOS transistor 24 has the function of selecting in read mode the memory element 10 to be addressed.
As an example, magnetic layer 12 of memory element 10 has a magnetic moment vector with a fixed orientation, whatever the amplitude of the magnetic field in which the memory element is bathed. Ferromagnetic layer 16 then has a magnetic moment vector with an orientation that can be modified by applying a magnetic field. As an example, binary data may be stored in the memory element by orienting the magnetic moment vector of ferromagnetic layer 16 in parallel or in antiparallel with respect to the magnetic moment vector of magnetic layer 12 .
A data write operation into memory element 10 is performed by flowing a current through bit line 18 and bit line 20 associated with the memory element. The flowing of a current in bit line 18 causes the forming of a magnetic field having the general orientation of the field lines represented by arrow 26 . Similarly, the flowing of a current in word line 20 causes the forming of a magnetic field having the general orientation of its field lines represented by arrow 28 . According to the flow direction of the current in bit line 18 and word line 20 , the magnetic moment vector of ferromagnetic layer 16 is oriented in parallel or in antiparallel with respect to the magnetic moment vector of magnetic layer 12 . In a write operation, MOS transistor 24 is on.
An operation of reading of the binary data stored in memory element 10 is performed by turning off transistor 24 associated with memory element 10 and by flowing a current therein via bit line 18 . The determination of the data stored in the memory element is based on the difference of the resistance of memory element 10 according to the orientation difference of the magnetic moment vectors of ferromagnetic layer 16 and of magnetic layer 12 .
FIGS. 2A to 2G show successive steps of a conventional example of a method for manufacturing such a memory element 10 in integrated form. Such a method is especially described in U.S. Pat. No. 6,673,675, which is incorporated herein by reference.
As shown in FIG. 2A , the magnetic memory is formed on a substrate 30 , for example, polysilicon, comprising insulation trenches 32 insulating the memory elements from one another. Two N-type doped regions 34 , 36 form the source and drain regions of MOS transistor 24 . The gate of MOS transistor 24 is formed of the stacking of a gate oxide layer 38 , for example, silicon oxide, and of a gate layer 40 , for example, polysilicon. Substrate 30 and the gate of MOS transistor 24 are covered with an insulating layer 42 . A connection portion 44 , for example, metallic, is buried at the surface of insulating layer 42 and is connected to doped region 36 via a contact 46 . A connection portion 48 , for example, metal, is buried at the surface of insulating layer 42 and is connected to doped region 34 via a via 50 . Connection portion 48 is intended to be grounded. A conductive track 52 , for example, metal, is buried at the surface of insulating layer 42 and forms word line 20 .
FIG. 2B shows the structure obtained after having covered insulating layer 42 with an insulating layer 54 , and having formed, in insulating layer 54 , a connection portion 56 , for example, metal, in contact with connection portion 44 .
FIG. 2C shows the structure obtained after having covered insulating layer 54 with an insulating layer 58 and formed, in insulating layer 58 , a connection portion 60 , for example, metal, in contact with connection portion 56 and which extends substantially above word line 52 .
FIG. 2D shows the structure obtained after having covered insulating layer 54 with an insulating layer 62 and etched a recess 64 with substantially straight sides in insulating layer 54 , exposing a portion of connection portion 60 .
FIG. 2E shows the structure obtained after having deposited, for example, by vapor phase deposition or cathode sputtering, on insulating layer 62 , a magnetic layer 66 , an insulating layer 68 , a ferromagnetic layer 70 , and a conductive layer 72 , for example, metal. The deposited layers penetrate into recess 64 so that magnetic layer 66 is in contact with connection portion 60 . Generally, magnetic layer 66 has a thickness of approximately some ten nanometers, insulating layer 68 has a thickness of a few nanometers, and ferromagnetic layer 70 has a thickness of from some ten nanometers to a few tens of nanometers.
FIG. 2F shows the structure obtained after a chem./mech polishing (CMP) of layers 66 , 68 , 70 , 72 down to insulating layer 62 . A memory element 73 formed of the stacking of magnetic, insulating, and ferromagnetic portions 74 , 75 , and 76 is thus insulated. Portions 74 , 75 , 76 thus defined comprise corner areas 77 , 78 , 79 . In other words, the resulting structure of memory element 73 after the planarization step has a “U”-shaped cross-section. Such corner areas 77 , 78 , 79 are undesirable since it is difficult to control the thickness of insulating portion 75 at the level of corner area 77 . In particular, there is a risk for the thickness of insulating portion 75 to be locally decreased at the level of corner area 77 . This may cause the occurrence of leakage currents between magnetic portion 74 and ferromagnetic portion 76 , altering the operation of memory element 73 . It is thus desirable to eliminate corner areas 77 , 78 , 79 .
FIG. 2G shows the structure obtained after etching of corner areas 77 , 78 , 79 of memory element 73 . A memory element 73 in which magnetic, insulating, and ferromagnetic portions 74 , 75 , and 76 are substantially planar is then obtained.
A disadvantage is that the materials generally used to form the memory elements are little reactive with the chemical etches conventionally used in integrated circuit manufacturing processes, since there is no forming of volatile compounds. It is thus necessary to use RIE-type etches (reactive ion etching) to eliminate corner areas 77 , 78 , 79 from memory element 73 . A disadvantage of such etchings is that the materials etched by an RIE-type etch tend to deposit back on the walls of the etch chamber and/or on other portions of the integrated circuit. This may result in a soiling of the etch chamber, and/or, which is much more disturbing, the occurrence of defects at the integrated circuit level.
SUMMARY OF THE INVENTION
The present invention aims at obtaining a memory element for a magnetic RAM exhibiting no “corner area” and capable of being formed by a process comprising no RIE-type etch steps.
Another object of the present invention is to provide a method for manufacturing such a memory element which is compatible with manufacturing processes currently used for integrated circuits.
Another object of the present invention is to provide a method for manufacturing such a memory element which only slightly modifies the steps of the general RAM manufacturing process.
For this purpose, the present invention provides a memory element for a magnetic RAM, comprising a first magnetic portion in a first recess of a first insulating layer; and a non-magnetic portion and a second magnetic portion in a second recess of a second insulating layer covering the first insulating layer, the second recess exposing the first magnetic portion and a portion of the first insulating layer around the first magnetic portion, the non-magnetic portion being interposed between the first and second magnetic portions.
According to an embodiment of the present invention, the first magnetic portion is connected to a source or drain region of a field-effect transistor.
The present invention also provides a magnetic RAM comprising an array of memory elements, such as described previously, distributed in rows and columns, and comprising, for each row, a conductive track extending along the row and intended for the writing of data into the memory elements of the row, the memory elements of the row being arranged above the conductive track with an interposed insulating layer.
The present invention also provides a magnetic RAM comprising an array of memory elements, such as previously described, arranged in rows and columns, and comprising, for each row, two conductive tracks extending along the row and intended for the writing of data into the memory elements of the row, the memory elements of the row being arranged at the level of the plane equidistant from the two conductive tracks.
The present invention also provides a method for manufacturing a magnetic memory element comprising digging a first recess into a first insulating layer; forming a first magnetic layer in the first recess and on the first insulating layer; etching, by chem/mech polishing, the first magnetic layer and a portion of the first insulating layer to delimit a first magnetic portion in the first recess; forming a second insulating layer; digging a second recess into the second insulating layer exposing the first magnetic portion and a portion of the first insulating layer around the first magnetic portion; forming a non-magnetic layer and a second magnetic layer in the second recess and on the second insulating layer; and etching, by chem/mech polishing, the second magnetic layer, the non-magnetic layer, and a portion of the second insulating layer to delimit a non-magnetic portion and a second magnetic portion in the second recess.
According to an embodiment of the present invention, the method comprises the previous steps of providing a silicon substrate at the level of which is formed a doped region; forming an insulating layer; forming a connection portion connected to the doped region and a conductive track adjacent to the connection portion, the conductive track being intended for the writing of data into the memory element; forming an insulating layer; forming a connection portion in contact with the intermediary connection portion and overhanging the conductive track; and forming said memory element above the conductive track, the first magnetic portion being connected to the connection portion.
According to an embodiment of the present invention, the method comprises the previous steps of providing a silicon substrate at the level of which is formed a doped region; forming an insulating layer; forming a connection portion connected to the doped region and two conductive tracks on either side of the connection portion, the two conductive tracks being intended for the writing of data into the memory element; and forming said memory element at the level of the plane equidistant from the two conductive tracks, the first magnetic portion being connected to the connection track.
The foregoing and other objects, features, and advantages of the present invention will be discussed in detail in the following non-limiting description of specific embodiments in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 , previously described, illustrates the operation of a magnetic RAM;
FIGS. 2A to 2G , previously described, illustrate successive steps of an example of a conventional method for manufacturing a magnetic RAM memory element;
FIGS. 3A to 3E illustrate successive steps of a first example of a manufacturing process according to the present invention of a magnetic RAM memory element; and
FIGS. 4A to 4D illustrate steps of a second example of a magnetic RAM memory element manufacturing process according to the present invention.
DETAILED DESCRIPTION
For clarity, the same elements have been designated with the same reference numerals in the different drawings and, further, as usual in the representation of integrated components, the various drawings are not to scale.
A first example of a process according to the present invention for manufacturing a magnetic RAM memory element will now be described in relation with FIGS. 3A to 3E . The initial steps of the first method example correspond to the steps previously described in relation with FIGS. 2A to 2D .
FIG. 3A shows the structure obtained after having deposited, for example, by vapor phase deposition, a layer 80 of a magnetic material, for example, cobalt, on insulating layer 62 and in recess 64 . Magnetic layer 80 penetrates into recess 64 to be in contact with connection portion 60 . According to a variation of the present invention, insulating layers 58 and 62 correspond to a single insulating layer which is deposited after forming of connection portion 60 .
FIG. 3B shows the structure obtained after a step of chem/mech polishing of magnetic portion 80 and of a portion of insulating layer 62 to delimit a magnetic portion 82 at the level of recess 64 .
FIG. 3C shows the structure obtained after a step of deposition of an insulating layer 84 on the structure of FIG. 3B , of etching of a recess 86 in insulating layer 84 to expose the entire magnetic portion 82 and a portion of insulating layer 64 surrounding magnetic portion 82 , and of successive depositions, for example, by vapor phase deposition, of an oxide layer 88 , and of a layer of a ferromagnetic material 90 , for example, a cobalt and iron alloy or a nickel and iron alloy, on insulating layer 84 and in recess 86 .
FIG. 3D shows the structure obtained after a step of etching by chem/mech polishing of ferromagnetic and oxide layers 90 and 89 and of a portion of insulating layer 84 to delimit at the level of recess 86 an oxide portion 92 and a ferromagnetic portion 94 . A memory element 96 comprising a “corner” area 95 at the level of the periphery of oxide portion 92 is thus obtained.
FIG. 3E shows the structure obtained after a step in which insulating layer 84 has been covered with an insulating layer 97 , a via 98 has been formed, in insulating layer 97 , coming to contact ferromagnetic portion 94 , and a conductive track 100 has been formed on insulating layer 97 in contact with via 98 . Conductive track 100 corresponds to the bit line associated with the column of the magnetic RAM to which memory element 96 belongs.
According to a variation of the present invention, a metal layer is deposited above ferromagnetic layer 90 . After the etch step, previously described in relation with FIG. 3D , a metal portion is then delimited at the level of ferromagnetic portion 94 . Via 98 is then formed at the contact of the metal portion.
The “active” region of memory element 96 corresponds to the region of oxide portion 92 for which magnetic portion 82 and ferromagnetic portion 94 are opposite. Corner area 95 of oxide portion 92 is not disturbing since it is not located at the level of the active region of memory element 96 . A local decrease in the thickness of oxide portion 92 at the level of corner area 95 thus does not disturb the operation of memory element 96 . Further, the present manufacturing method comprises no RIE-type etch steps since memory element 96 is only delimited by chem/mech polishing steps. Thereby, the risk of uncontrolled deposition of the materials forming the memory element in the etch chamber or on the integrated circuit, characteristic of an RIE-type etch, is avoided.
A second example of a method for manufacturing according to the present invention a magnetic memory will now be described in relation with FIGS. 4A to 4D .
FIG. 4A shows a structure similar to FIG. 2A . However, conversely to the structure shown in FIG. 2A , two conductive tracks 110 , 112 corresponding to two word lines are provided for each row of the magnetic RAM. For each memory element of a same row, conductive tracks 110 , 112 extend on either side of connection portion 44 .
FIG. 4B shows the structure obtained after deposition of an insulating layer 114 on insulating layer 42 , the etching of a recess 116 in insulating layer 42 which exposes connection portion 44 , and the deposition of a layer of a magnetic material 118 , for example, cobalt-based, on insulating layer 114 . Magnetic layer 118 penetrates into recess 116 to contact connection portion 44 .
FIG. 4C shows the structure obtained after a chem/mech polishing of magnetic layer 118 and of a portion of insulating layer 114 to delimit a magnetic portion 120 in recess 116 .
FIG. 4D shows the structure obtained after implementation of steps similar to those illustrated in relation with FIGS. 3C and 3D of the first example of embodiment.
The structure of memory element 96 obtained by the second example of a manufacturing process according to the present invention is identical to that obtained by the first example of a manufacturing process according to the present invention. In particular, corner area 95 of oxide portion 92 is insulated from the active region of memory element 96 and does not disturb its operation.
An operation of data writing into memory element 96 is performed by running a current in the bit line and currents of opposite directions in word lines 110 , 112 . A magnetic field having its maximum amplitude substantially at the level of a plane equidistant from word lines 110 , 112 , that is, substantially at the level of magnetic memory element 96 is then obtained.
In the first example of embodiment in which a single word line 52 is associated with each row of the magnetic RAM, it is necessary for memory element 96 to be arranged above word line 52 to benefit from a magnetic field of maximum amplitude in a write generation. In the second method example, the magnetic field has a maximum amplitude at the level of the plane equidistant from the two word lines 110 , 112 . This enables leaving memory element 96 above connection portion 44 . It is then no longer necessary to provide the steps of deposition of insulating layers 54 and 58 and the steps of forming of connection portions 56 and 60 of the first method example. The second method example thus enables reducing the number of masks to be provided for the memory element manufacturing.
According to a variation of the previously-described examples of embodiment, the MOS transistor associated with each memory element and used for the reading of the data stored at the level of the memory element may be replaced with a diode circuit.
According to another variation of the previously-described examples of embodiment, a single word line is associated with each row of the magnetic RAM and is connected to all the memory elements in the row. Each memory element is then caught between the bit line and the word line associated with the memory element. An operation of reading of the data stored at the level of a memory element is then performed by running a current through the memory element via the bit line and the word line associated with the memory element. Such an alternative embodiment enables suppressing the MOS transistor associated with each memory element.
The present invention has many advantages.
First, it enables obtaining a magnetic RAM for which, at the level of the active region of each memory element, the thickness of the oxide portion is relatively uniform.
Second, the steps of the manufacturing process of each memory element according to the present invention relative to the etching of the materials forming the memory element only implement chem/mech polishing steps instead of RIE-type etchings. The disadvantages of RIE-type etchings are thus avoided.
Third, the manufacturing process according to the present invention only implements layer deposition steps and chem/mech polishing etch steps, which are compatible with usual integrated circuit manufacturing processes.
Fourth, the manufacturing process according to the present invention comprises but a small number of additional steps and thus only slightly modifies usual magnetic RAM manufacturing steps.
Of course, the present invention is likely to have various alterations, modifications, and improvements which will occur to those skilled in the art. In particular, the magnetic layer, the oxide layer, and the ferromagnetic layer based on which the memory element is formed may each be formed of the stacking of several layers.
Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and the scope of the present invention. Accordingly, the foregoing description is by way of example only and is not intended to be limiting. The present invention is limited only as defined in the following claims and the equivalents thereto.
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A memory element for a magnetic RAM, having a first magnetic portion in a first recess of a first insulating layer; and a non-magnetic portion and a second magnetic portion in a second recess of a second insulating layer covering the first insulating layer, the second recess exposing the first magnetic portion and a portion of the first insulating layer around the first magnetic portion, the non-magnetic portion being interposed between the first and second magnetic portions.
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This patent application is a divisional of patent application Ser. No. 10/161,966 filed Jun. 3, 2002, now U.S. Pat. 6,848,273.
FIELD OF THE INVENTION
This invention relates to a method of and an apparatus for blowing glass containers in molds of a glass container forming machine and for removing blown containers from such molds. More particularly, this invention relates to a method of and an apparatus for blowing glass containers in blow molds of an I.S. (individual section) glass container forming machine, and for thereafter removing blown containers from such molds and transferring the blown containers to a deadplate of the machine for cooling and eventual removal for further processing.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 3,472,639 (Mumford) and U.S. Pat. No. 4,427,431 (Mumford et al.), which were assigned to a predecessor of the assignee of this application, the disclosure of each of which is incorporated by reference herein, generally describe the manufacture of glass containers by a machine type that is known as an I.S. machine. As taught by such references or as is otherwise known, an I.S. machine has a plurality of side-by-side sections, usually six, eight, ten or even twelve sections, and containers are formed in each section in a two step process. In the first step, one or more, and often three or four, container preforms, which are often called parisons or blanks, are formed by blowing or pressing. The preforms, which are formed in an inverted orientation, that is, with their open ends down, have body portions that are formed in split molds, often called blank molds. Threaded or otherwise suitable configured closure-receiving finish portions of such preforms are formed in separate molds, usually referred to as neck molds or neck rings, which are positioned adjacent to the split blank molds during the molding of parisons therein.
After the conclusion of the parison molding step, the split molds open and the parisons, which are then gripped by the neck molds, are transferred by inverting them through an arc of 180° to split blow molds for blowing of the parisons into containers. The inverting step is performed by turning an invert shaft, to which neck mold-carrying arms are slideably affixed, and results in the parisons being upright during blow molding, that is with their open ends up. The transferring of glass container parisons or blanks from blank molds to blow molds of a I.S. machine, as generally described above, is generally described in commonly-assigned U.S. Pat. No. 5,893,942 (Nickey et al.) and U.S. Pat. No. 6,098,427 (Kirkman), the disclosure of each of which is also incorporated by reference herein.
Conventionally, as is explained, for example, in U.S. Pat. No. 3,630,709 (Irwin), which was assigned to a predecessor of the assignee of this application, the disclosure of which is also incorporated by reference herein, containers are blown in blow molds of an I.S. machine by a blowhead that is moved into blowing engagement with the parisons in the blow molds at a given I.S. machine section, and is then moved out of engagement with blown containers at such blow molds. The blown containers are then removed from the blow molds, after the split molds are opened, by a takeout mechanism that is equipped with a plurality of tongs, one set of tongs for each blow mold at the section of the I.S. machine with which the takeout mechanism is associated. Commonly-assigned U.S. Pat. No. 6,241,448 B1 (Nicholas), the disclosure of which is also incorporated by reference herein, describes a takeout mechanism as generally described above for removing blown containers from molds of an I.S. machine section. U.S. Pat. No. 5,807,419 (Rodriquez-Wong et al.) describes an I.S. machine in which the functions of a blowhead and a takeout mechanism are combined in a single mechanism. However, the mechanism of the '419 reference teaches the use of conventional pivoting tongs (elements 72 , 73 ) to engage each container below a bead, called a transfer bead, that is positioned below the threaded or otherwise configured finish of a container, and this requires that the split blow mold be opened before the blown containers can be grasped for removal by the tongs. The requirement that blow molds be opened before the blown container can be grasped by tongs is a machine timing disadvantage for reasons explained in the aforesaid '488 B1 patent.
BRIEF DESCRIPTION OF THE INVENTION
According to the present invention there is provided a combined blowhead/takeout mechanism for an I.S. glass container forming machine, and a method for blowing glass containers in blow molds of such a glass container forming machine and removing blown containers from such molds. The apparatus includes a container finish engaging chuck for each of the containers that are simultaneously formed at a section of the I.S. machine, and each chuck includes a plurality, preferably three, circumferentially spaced-apart elements that move in and out, in unison, to engage a container by its finish. In this way, the container may be engaged by the chuck while the split molds in which the container is being blown remain closed, to thereby permit the container to be removed for transfer to a deadplate of I.S. machine immediately upon the opening of the split molds of the blow machine in which the container was formed. This eliminates the lost cycle time of certain prior art takeout devices, such as that of the aforesaid '419 patent, which require that the split mold be opened before a container with a transfer bead can be engaged by the takeout device.
In a preferred embodiment of the present invention, a pair of combined blowhead/takeout mechanisms is provided at each section of an I.S. machine. The combined mechanisms are timed to operate alternatively so that one combined mechanism can be positioned to blow containers in the blow molds of the machine while the other combined mechanism is positioned, after depositing blown containers on the machine deadplate, to immediately return to the blow molds to begin a repeat of the blow molding cycle. This eliminates lost cycle time that can arise in an I.S. machine with only a single blowhead at each machine section, as the blowing cycle can not begin until the blowhead returns from having deposited blown containers on the machine's deadplate. To avoid collision of the separate combined mechanisms during operation, the pivot axis of the pivoting arm of each combined mechanism is moveable in a vertical plane, so that the incoming combined mechanism can be positioned at an elevation above that reached by the outgoing combined mechanism during its pivoting motion to transfer blown containers from the blow molds to the machine deadplate. The use of a pair of combined blowhead/takeout mechanisms in this manner improves forming cycle time because it ensures that a combined blowhead/takeout mechanism will be positioned at the blow molds when the molds close around parisons that were transferred to the molds without the need to wait for the return of a blowhead from the machine deadplate after depositing previously blown containers thereon.
Accordingly, it is an object of the present invention to provide an improved apparatus and method for blowing containers from parisons of formable glass in blow molds of a glass container forming machine and for transferring blown containers from the blow molds to a different position for further processing. More particularly, it is the object of the present invention to provide an improved method and apparatus of the foregoing character in which the parisons are blown in blow molds of a glass container forming machine of the I.S. type, and are then transferred to a deadplate of the I.S. machine for cooling and eventual further processing.
For a further understanding of the present invention and the objects thereof, attention is directed to the drawing and the following brief description thereof, to the detailed description of the invention and to the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1–6 are schematic elevational views showing apparatus according to the present invention at different positions during the operating cycle of such apparatus.
FIG. 7 is an elevation view at an enlarged scale, of a portion of the apparatus of FIGS. 1–6 ;
FIG. 8 is a sectional view taken on line 8 — 8 of FIG. 7 ;
FIG. 9 is a sectional view taken on line 9 — 9 of FIG. 7 ;
FIG. 10 is a sectional view taken on line 10 — 10 of FIG. 7 ;
FIGS. 11A , 11 B, collectively, constitute upper and lower views, respectively, and at an enlarged scale, taken on line 11 — 11 of FIG. 7 ;
FIG. 12 is a sectional view taken on line 12 — 12 of FIG. 7 ;
FIG. 13 is an exploded, perspective view of a portion of the apparatus of FIGS. 7–12 ; and
FIG. 14 is an exploded, perspective view at an enlarged scale, of another portion of the apparatus of FIGS. 1–6 .
DETAILED DESCRIPTION OF THE INVENTION
As is shown schematically in FIGS. 1–6 , an I.S. machine section 20 , shown fragmentarily, is provided with a set of blow molds 22 in which containers C are blown from blanks or parisons P of a glass composition at a suitable high temperature to be formable by blowing. FIGS. 1–6 show three containers being formed in each set of blow molds, but it is to be understood that the invention is suited for use in I.S. machines that are designed to simultaneously produce as many as four containers at each machine section (a “quad” machine), or even as few as one container at each such section. In any case, as is understood in the art, each set of blow molds 22 is made up of an opposed set of split molds that periodically open and close with respect to each other by counteroscillating or counterrectilinear motions to define, when closed, a cavity for each container C to be formed therein.
The parisons P to be formed into the containers C in the mold set 22 are transferred thereto from a blank molding side of the machine section by neck molds 24 , as shown specifically in FIG. 5 . The neck molds 24 are carried by an invert or neck mold arm assembly 26 that is connected to an oscillatable invert or neck mold shaft 28 , often referred to as a rock shaft, that oscillates in a 180° arc between the position shown on FIG. 1 and the position shown in FIG. 5 . Upon the transfer of the parisons P to the mold set 22 , the invert arm assembly 26 , with the neck molds 24 carried thereby, reverts from the FIG. 1 position to the FIG. 5 position to begin a repeat of the glass container manufacturing process in the mold set 22 , following the removal of the previous blown containers C therefrom.
The I.S. machine section 20 is provided with a side-by-side pair of combined blowhead/takeout mechanisms 30 , 32 , each of which carries a plurality of individual blowheads 34 , one such blowhead 34 for each container C being formed in the mold set 22 . The blowhead mechanism 30 is shown in detail in FIGS. 7–13 at the position shown in FIG. 6 , but it is to be understood that the blowhead 32 is of the same construction as the blowhead 30 . In any case, each of the blowhead mechanisms 30 , 32 is made up of a carrier arm 36 , from which the blowheads 34 are suspended, and an oscillating arm 38 , from which the carrier arm 36 is suspended for pivoting motion from the oscillating arm 38 about an axis A. Each carrier arm 36 is pivoted from the oscillating arm 38 of the blow head mechanism 30 or 32 of which it is an element by a parallel linkage or other equivalent structure in a known manner, to ensure that it does not change the angular position of the blowheads 34 that are carried by the carrier arm 36 as the oscillating arm 38 oscillates, for example, from the position of the blowhead mechanism 30 in FIG. 1 to its position in FIG. 6 .
FIG. 1 depicts the position of the blowhead mechanism 32 immediately above a deadplate 40 of the I.S. machine section 20 to be able to deposit blown containers C thereon. In this condition of the apparatus, the blowhead mechanism 30 is positioned in vertical alignment with a tower 42 to which the blowhead mechanism 30 is secured for pivoting motion about an axis B. Likewise, the blowhead mechanism 32 is secured for pivoting motion about an axis B to a second tower (not shown), which is immediately behind and a mirror image of the tower 42 . In that regard the pivot axis B for each of the blowhead mechanisms 30 , 32 is vertically moveable, by structure that will be hereinafter described in greater detail, between a lower position, for example, that of the blowhead mechanism 32 in FIG. 1 , to the higher position of the blowhead mechanism 32 in FIG. 4 , to permit the blowhead mechanisms 30 , 32 to oscillate between the positions shown in FIG. 1 and the positions shown in FIG. 4 without interfering contact between the blowhead mechanisms 30 , 32 , which are aligned in the same vertical plane. In this manner, the blowheads 34 of the blowhead mechanism 32 will be positioned to immediately engage parisons P in the molds 22 while the blowhead mechanism 30 is enroute to deposit containers C on the deadplate 40 , as can be seen from a comparison, for example, of FIGS. 4 and 6 . This permits a substantial calculated reduction in cycle time between the removal of the set of containers C from the mold set 22 and the removal of the next set of containers C from the mold set 22 , compared to an installation using only a single blowhead/takeout mechanism, of approximately 13%, and it does so without reducing the time available for the cooling of the containers C on the deadplate 40 before it is necessary to remove partly-cooled containers C from the deadplate 40 to accommodate the transfer of freshly formed containers C to the deadplate 40 . Alternatively, cycle improvement can be somewhat reduced by moving the blowheads 30 , 32 more slowly to reduce inertial forces on the blown containers C. In any case, the reduction in cycle time can be enhanced by approximately 4%, that is, to a total of approximately 17%, if each pair of combined blowheads/takeout mechanisms is adapted to engage blown containers C by finishes before the split molds of the mold set 22 are separated, without the need to delay the engagement of containers C until the split molds are open, which is required when transferring blown containers from the mold set 22 by engagement of a transfer bead by tongs of a conventional takeout mechanism. This phenomenon is described in the aforesaid '488 B1 patent. Further, the use of blowheads to transfer blown containers C to the deadplate 40 permits partial cooling of the containers C by blowing air going to the blowhead 30 or 32 during the transfer step.
As shown in FIG. 7 , the blowhead mechanism 30 has a generally trapezoidial-shaped frame 44 that carries the blowheads 34 , each of which is quickly disengageable from the frame 44 by way of a disconnect 35 ( FIG. 11B ). The frame 44 is provided with a split annular member 46 that extends therethrough, above and parallel to the orientation of the containers C that are carried by the blowhead 30 . A reversing, double acting pneumatic cylinder 48 is positioned between the ends of the annular member 46 , and the cylinder 48 drives a split rack 50 ( FIG. 8 ) that extends from opposed ends through the annular member 46 . The split rack 50 , which reciprocates but does not rotate, engages, in a right-angle drive, a screw 52 associated with each of the blowheads 34 to simultaneously open or close a container finish-engaging tong or chuck assembly 54 ( FIGS. 9 , 10 ) that is associated with each of the blowheads 34 .
As shown in FIGS. 7 , 11 A, the frame 44 is made up of a generally triangularly-shaped upper member 56 bolted or otherwise adjustably secured to a lower member 58 with an alignment plate 57 positioned therebetween to ensure proper alignment between the upper member 56 and the lower member 58 , which have aligned openings therein. The upper member 56 is affixed to the oscillating arm 38 for oscillation with the oscillating arm 38 between the position shown in FIGS. 3 and 4 and the position shown in FIG. 6 , and the lower member 58 carries the elements associated with each of the blowheads 34 . As shown in FIG. 12 , cooling air for the cooling of each of the blowheads 34 is circulated through a passage 60 in the lower member 58 , and blow air for blowing parisons P into containers C, in the position of the blowhead mechanism 30 shown in FIGS. 3 , 4 , is introduced through a passage 62 in the lower member 58 . The air for the operation of the cylinder 48 , which is shown as a pair of like cylinders disposed tail end to tail end, is introduced through inlet lines 64 , which receive air from passages 64 a , 64 b in the lower member 58 . Blowing air from the passage 62 blows downwardly into a parison F that is being blown into a container C through a transfer tube 66 , an upper end which is resiliently biased downwardly by a compression spring 68 , an O-ring 70 being provided to permit sealed, sliding motion between an enlarged upper end of the transfer tube 66 and a passage in the lower member 58 in which the upper end of the transfer tube 66 is positioned. A lower end of the transfer tube 66 seats against and discharges into an upper end of a blow air inlet tube 72 ( FIG. 11B ) that extends into a parison P or a container C, as the case may be, that is engaged by the blowhead 34 with which the air inlet tube 72 is associated.
Each tong assembly 54 carries a circumferentially-spaced plurality, shown as three, tong elements 74 that simultaneously are powered to move radially either inwardly to grasp a finish F ( FIG. 11B ) of a container C or outwardly to release the finish F of the container C. While the container C is shown as having a finish F for the application of a crown closure to the container C, it is also contemplated that the finish F engaging surface of the tong elements 74 may be configured to handle containers C with threaded finishes F. In that regard, each of the tong elements 74 is retained within a tong holder 75 and has an upperwardly extending pin 76 that is received in an annular cam follower 77 , which rides in a noncircular slot 78 of a lobe of an oscillating cam 80 . Oscillation of the cam 80 , by the extension and retraction of the split rack 50 , is effective to simultaneously move the tong elements 74 of each of tong assembly 54 into or out of engagement with a finish (F) of a container (C). The assembly that includes the tong elements 74 and the tong body 76 is slideable within an annular tong housing 79 , and rearward travel of such assembly is limited by a pin 81 , whose position along its longitudinal central axis is adjustable.
The screw 52 of each blowhead 34 is secured to an annular member 82 that surrounds the transfer tube 66 , bushings 84 being provided within a recess 86 in the blowhead mechanism 30 at opposed ends of the transfer tube 82 to permit it to oscillate, with the screw 52 and the transfer tube 66 , around the longitudinal central axis of the transfer tube 66 . A lowermost end of the transfer tube 66 is provided with an externally threaded plug 86 , and the cam 80 , which has an upstanding annular portion 80 a that is rotatable in a bushing 88 , is threadably secured to an exterior of the plug 86 to be rotatable therewith. The cam 80 is also threadably secured to an extension of an upper portion 72 a of the air inlet tube 72 to be rotatable therewith; thus, reciprocation of the split rack 50 is effective to oscillate the screw 52 , and, thereby, to oscillate the cam 80 to move the tong elements 74 inwardly and outwardly, as desired. However, an annular brake assembly 90 is provided surrounding a portion of upstanding portion 80 a of the cam 80 to prevent oscillating motion of the cam 80 when desired.
FIG. 14 illustrates apparatus, which has previously been identified as the lower A 2 , for raising and lowering the axis of the blowhead mechanisms 30 , 32 . FIG. 14 illustrates such apparatus specifically in reference to the blowhead mechanism 30 , and the tower 42 to which it is pivotably secured, but it is to be understood that apparatus for raising and lowering the blowhead mechanism 32 is the same in design and construction as that for the blowhead mechanism 30 . The oscillation of the arm 38 about the axis B is powered by a rack 92 , whose rectilinear motion is powered by a reversible motor 94 , preferably an a.c. servo motor for optimum controllability. Oscillation of the motor 94 results in oscillation of a gear assembly 95 , which slides upwardly and downwardly on a ball spline 99 that extends to the gear assembly 95 from the motor 94 . The rack 92 drives a spur gear 96 that is affixed to a shaft 98 , through which the axis B extends and to which the arm 38 is connected for turning with the shaft 98 .
The shaft 98 is rotatably mounted in a bracket 100 , and the elevation of the bracket 100 , and thereby that of the shaft 98 and the oscillating arm 38 , is adjustable based on a rotary motor 102 , preferably an a.c. servo motor, which engages a screw 103 that elevates or lowers a bracket 104 from which the bracket 100 is supported by vertical support 106 , 108 , the support 108 being annular and surrounding a lowermost portion of the rack 92 . Thus, the oscillation of the shaft 98 , and thereby of the oscillating arm 38 , is powered by the motor 94 , independently of the raising and lowering of the shaft 98 , and thereby the oscillating arm 38 , which is powered by the motor 102 , subject to an electronic or other control system, which may be of conventional construction, that is used to control the operation of the motor 94 and the motor 102 in a timed sequence relative to one another.
Although the best mode contemplated by the inventors for carrying out the present invention as of the filing date hereof has been shown and described herein, it will be apparent to those skilled in the art that suitable modifications, variations, and equivalents may be made without departing from the scope of the invention, such scope being limited solely by the terms of the following claims and the legal equivalents thereof.
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Vertically aligned first ( 30 ) and second ( 32 ) combined blowhead and takeout mechanisms are provided to sequentially blow glass parisons (P) into containers (C) in a mold set ( 22 ) and to transfer blown containers to a deadplate ( 40 ) of a glass containing forming machine ( 20 ). Each of the combined mechanisms is pivotally suspended about an axis A from a carrier arm ( 36 ) that is pivotally attached to an end of an oscillating arm ( 38 ), an opposed end of which is pivoted about an axis (B). The axis (B) of each combined blowhead and takeout mechanism is periodically raised and lowered to permit the other combined blowhead and takeout mechanism to oscillate therebeneath, to thereby permit overlapping cycles between the blowhead and takeout mechanisms. Each blowhead and takeout mechanism is provided with a chuck or tong assembly ( 54 ) to engage or release each container by its finish (F). Each tong assembly has a plurality of tong elements ( 74 ) that are simultaneously moved radially in or out by oscillation of a cam ( 50 ) that has a non-circular slot ( 78 ) in which a pin ( 76 ) carried by each tong element rides.
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FIELD OF THE INVENTION
The present invention relates to reclosable plastic bags of the type in which perishable food products and other goods are packaged for sale to consumers in retail outlets. More specifically, the present invention relates to a method of producing plastic bags which are concurrently manufactured to include a fin seal, and the manner of producing such bags so that they may more readily be torn open through the fin seal.
DESCRIPTION OF THE PRIOR ART
The present invention relates to improvements in the package-making art and may be practiced in the manufacture of reclosable thermoplastic bags and packages of the type that may be used for various consumer products. Such packages often include a form of peel-seal to render the package moisture-tight and/or airtight prior to the initial opening, and/or a tamper-evident seal. A zipper means protects any remainder of the product therein after the initial opening.
The indicated art is fairly well developed but nevertheless remains open to improvements contributing to increased efficiency and cost-effectiveness. In the prior art, McMahon et al. (U.S. Pat. No. 4,909,017) discloses a method of making a form-fill and seal bag having a reclosable fastener. Prior to entering the form-fill and seal machine, fastener strips are attached to the surface of the film transverse to the running direction at bag length intervals. The fastener strips contain pre-joined interlocked rib and groove strips. Only one of the strips is attached to a top surface of the film with the other strip facing upwardly or, in other words, inwardly toward the interior of the bag to be formed. The attached strips are secured in one form at the center of the film and each strip is less than half of the film width. The film is then advanced to the form-fill and seal machine and is drawn down over a forming collar and about the filling tube, with the longitudinal side edge margins of the film brought together and seamed with a fin seal to form a tube. Cross-seals are made across the tube to join the unattached fastener strip to the film to form the closure and to form the bottom of the following bags. A further seal may be provided above the fastener to provide tamper-evident sealing. In such case, an easy-open feature such as a line of weakness in the form of a line of perforations or a score line would be provided for the bag between the top seal and the fastener strip.
A potential problem with the above method is that the bag walls contain layers which will be doubled or tripled in the area of the fin seal which must be tom through to open the bag. While the line of weakness aids in starting the tear through the bag walls, tearing through multiple layers of the fin seal and the underlying bag may be difficult for the consumer to achieve. A significant step would involve reducing the amount of layers of bag film in the fin seal or weakening the layers of bag film in the fin seal area. When opening the bag by tearing along provided perforations or a score line in the bag, the fin area would be a reduced impediment, thus providing the bag with an easy-open feature.
SUMMARY OF THE INVENTION
Accordingly, the present invention relates to a method for producing a reclosable plastic bag with an easy-open feature in which a length of bag making film is advanced in a bag forming direction. A length of fastener having first and second mateable profile strips is attached to a mid-portion of the bag making film transverse to the bag forming direction, while leaving sides of film on opposite ends of the length of fastener. A weakness area is created in at least one of the sides with the weakness area comprising either an aperture, multi-line perforations of the bag film, scoring of the bag film, or any other weakening method known to those skilled in the art. The weakness area aligns with a flange portion of one of the profile strips or with an area of film adjacent the flange portion.
In a later stage of manufacture, the weakness area extends into a side margin that runs to an edge of one of the sides. The side margin of one side, together with a side margin of an opposite side, is sealed in a fin seal to form a tube. The unattached length of fastener is sealed to the inner surface of the tube that includes the fin seal. When the fin seal is formed, and if the weakness area comprises an aperture aligning with the flange portion, a portion of the opposite side margin of the fin seal is sealed to the flange portion of the fastener through the aperture. If the weakness area comprises an aperture aligning with an area of film adjacent the flange portion, a portion of the opposite side margin of the fin seal is sealed to the bag making film of the front bag wall through the aperture. Alternatively, a weakness area other than an aperture can be created when the fin seal is formed, instead of at the stage of manufacturing described earlier. In the last stage of manufacturing, the tube is cross-sealed at spaced intervals to form a bag. An opening notch is provided to create a tear line that will run through the weakness area.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the invention will become apparent from the following description and claims taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a plan view depicting a first embodiment of the present invention wherein a perforated fastener with an adjacent elliptical aperture is formed on a section of thermoplastic film;
FIG. 2A is a side view depicting the first embodiment of the present invention wherein the thermoplastic film is folded to provide a fin seal area;
FIG. 2B is a sectional view depicting the first embodiment of the present invention taken from reference line 2 B— 2 B of FIG. 2A ;
FIG. 3A is a side view depicting the first embodiment of the present invention wherein a fin seal has been formed at a cross-jaw section of a form-fill and seal machine;
FIG. 3B is a sectional view depicting the first embodiment of the present invention taken from reference line 3 B— 3 B of FIG. 3A ;
FIG. 4 is a side view depicting the first embodiment of the present invention wherein the fin seal has been sealed to a wall of the reclosable bag;
FIG. 5 is a side view depicting the first embodiment of the present invention with a reclosable bag shown in an opening condition;
FIG. 6 is a plan view depicting a second embodiment of the present invention wherein a perforated fastener with adjacent multi-line perforated areas of weakness is formed on a section of thermoplastic film;
FIG. 7A is a side view depicting the second embodiment of the present invention wherein a fin seal has been formed at a cross-jaw section of a form-fill and seal machine;
FIG. 7B is a sectional view depicting the second embodiment of the present invention taken from reference line 7 B— 7 B of FIG. 7A ;
FIG. 8 is a side view depicting the second embodiment of the present invention wherein a reclosable bag has been formed;
FIG. 9 is a side view depicting the second embodiment of the present invention with the reclosable bag shown in an opening condition;
FIG. 10 is a plan view depicting a third embodiment of the present invention wherein a perforated fastener with adjacent multi-line perforated areas of weakness is formed on a section of thermoplastic film;
FIG. 11 is a side view depicting the third embodiment of the present invention wherein a fin seal has been formed at a cross-jaw section of a form-fill and seal machine;
FIG. 12 is a side view depicting the third embodiment of the present invention wherein a reclosable bag has been formed;
FIG. 13 is a side view depicting the third embodiment of the present invention with the reclosable bag shown in an opening condition;
FIG. 14 is a plan view depicting a fourth embodiment of the present invention wherein a fastener with an adjacent elliptical aperture is formed on a section of thermoplastic film;
FIG. 15 is a side view depicting the fourth embodiment of the present invention wherein a fin seal has been formed at a cross-jaw section of a form-fill and seal machine;
FIG. 16 is a side view depicting the fourth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch on the edge of the reclosable bag;
FIG. 17 is a side view depicting the fourth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch formed in the cross-seal of the reclosable bag;
FIG. 18 is a side view depicting the fourth embodiment of the present invention with the reclosable bag shown in an opening condition;
FIG. 19 is a side view depicting the fourth embodiment of the present invention with the reclosable bag shown in an alternative opening condition;
FIG. 20 is a plan view depicting a fifth embodiment of the present invention wherein a fastener with adjacent multi-line perforated areas of weakness is formed on a section of thermoplastic film;
FIG. 21 is a side view depicting the fifth embodiment of the present invention wherein a fin seal has been formed at a cross-jaw section of a form-fill and seal machine;
FIG. 22 is a side view depicting the fifth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch on the edge of the reclosable bag;
FIG. 23 is a side view depicting the fifth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch formed in the cross-seal of the reclosable bag;
FIG. 24 is a side view depicting the fifth embodiment of the present invention with the reclosable bag shown in an opening condition;
FIG. 25 is a side view depicting the fifth embodiment of the present invention with the reclosable bag shown in an alternative opening condition;
FIG. 26 is a plan view depicting a sixth embodiment of the present invention wherein a fastener with adjacent multi-line perforated areas of weakness is formed on a section of thermoplastic film;
FIG. 27 is a side view depicting the sixth embodiment of the present invention wherein a fin seal has been formed at a cross-jaw section of a form-fill and seal machine;
FIG. 28 is a side view depicting the sixth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch on the edge of the reclosable bag;
FIG. 29 is a side view depicting the sixth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch formed in the cross-seal of the reclosable bag;
FIG. 30 is a side view depicting the sixth embodiment of the present invention with the reclosable bag shown in an opening condition;
FIG. 31 is a side view depicting the sixth embodiment of the present invention with the reclosable bag shown in an alternative opening condition;
FIG. 32 is a side view depicting the sixth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch formed in an alternative position in the cross-seal of the reclosable bag; and
FIG. 33 is a side view of the sixth embodiment of the present invention with the reclosable bag shown in an alternative opening condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in detail wherein like numerals indicate like elements throughout the several views, a continuous length of thermoplastic packaging film 10 is shown in FIG. 1 prior to sealing, where the film would be fed to a form-fill and seal machine in movement direction 12 .
In accordance with the present method, a fastener strip 14 with male and female profiles joined by their interlocking elements is attached to the midsection of the film 10 extending in a direction transverse to movement direction 12 . Only profile 16 that sits on the thermoplastic film 10 is attached to the film. The other profile 18 , as depicted in FIG. 2B , is secured only by the engagement of the interlocking elements.
In FIG. 1 , a line of weakness is set along perforation axis 19 on a flange of the profile 16 prior to its attachment to the film. Alternatively, a line of weakness may also be set along perforation axis 20 prior to its attachment to the film, with the positioning of the perforation axis 20 illustrated in FIG. 2 A. The lines of weakness may be perforations, dimples, scoring of the film, or any other tearing axes known to those skilled in the art. The positioning of the lines of weakness will hereinafter be referred to as on perforation axis 19 , since perforation axis 20 is preferably collinear with perforation axis 19 . Also, any tearing action or dimensioning regarding the present invention similarly affects perforation axis 20 as well as perforation axis 19 . As such, perforation axes 19 and 20 are parallel to the interlocking profiles and end short of the longitudinal ends of the fastener strip, thereby protecting the lines of weakness from prematurely tearing open during the manufacturing process.
Sides 21 and 22 of thermoplastic film extending to the longitudinal film edges are provided on opposite sides of the fastener strip 14 . In this regard the combined length of sides 21 and 22 is greater than that of the fastener strip to allow proper sealing, as will be discussed later. An area of weakness is created on the side 21 to align with the perforation axis 19 or to be to the right of and parallel with the fastener strip 14 . The area of weakness may comprise an aperture 23 , as shown in FIGS. 1-5 , 14 - 18 , or lines of weakness 80 , 81 , 84 , 86 , as shown in FIGS. 6-13 , 20 - 33 .
As shown in FIG. 1 the aperture 23 , preferably elliptical, is cut or punched through the thermoplastic film 10 such that the longitudinal axis of the aperture 23 aligns with the perforation axis 19 . The outer edge of aperture 23 should be in proximity to a longitudinal edge 24 of the thermoplastic film, but should also allow a sufficient buffer between the longitudinal edge to prevent the film from tearing to the aperture 23 from the longitudinal edge during the manufacturing process.
As shown in FIGS. 2A and 2B , during the bag forming process the thermoplastic film 10 is folded on the form-fill and seal machine to bring side margins 25 and 26 , respectively adjacent the longitudinal edges of the film, together in a fin to thereby form the thermoplastic film into a tube. The wall sections 28 and 30 , corresponding to sides 21 and 22 that extend from the opposite ends 32 and 34 of the zipper strip, are joined by the fin to define a rear surface of the tube that faces the fastener strip 14 . In FIG. 3A the side margins 25 and 26 are seamed together to form a fin seal 35 , and a cross-jaw sealing section is used to seal wall sections 28 and 30 to the profile 18 . When folding the film to form the fin seal 35 , more than half of the aperture 23 should be on the side margin 25 with the remainder of the aperture on the adjacent wall section 28 .
As shown in FIG. 3B , the use of the cross-jaw sealing section of a form-fill and seal machine (not shown) seals wall sections 28 , 30 to an upper flange 36 of profile strip 18 of the fastener strip 14 while preferably avoiding pressure on the perforation axes 19 and 20 . In FIG. 4 , the thermoplastic film is folded into a tube with the fin seal 35 sealed to wall section 28 . Because of the removed layers of the wall section 28 created by the aperture 23 , the fin seal side margin 26 now seals directly to the upper flange 36 of the profile strip 18 . The thermoplastic film is now formed as a reclosable bag 38 by forming a bottom cross-seal and a top cross-seal 39 above the profiles.
To assist in reaching the perforation axes 19 , 20 of the reclosable bag 38 during an opening operation, a tear notch 50 is formed by cutting or melting away material from an edge of the reclosable bag 38 . For the tear notch 50 , the edge selected should be closer to the fold line 52 in the aperture than to the folded-over ends 54 and 55 of the aperture.
If a hermetic seal is necessary for the notch 50 , a melting operation is used to form the notch. A peripheral melt zone 56 would join the front and rear walls of the package around the notch and hence would seal the contents of the interior of the reclosable bag from exposure via the notch.
FIG. 5 depicts the reclosable bag 38 in an opening condition. The notch 50 is separated by a tearing force produced by the user, thereby allowing the tearing force to continue to a resultant perforation 57 of the bag. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced by exposed sealing areas 59 since the tearing force is exposed to only the side margin 26 of the fin seal.
A second embodiment of the present invention is shown in FIG. 6 . In the figure, the weakness area comprises a line of weakness 80 instead of the aperture 23 . An opposing line of weakness 81 is positioned on the opposite side of the fastener 14 . The lines of weakness 80 , 81 may be a plurality of perforated lines on the film used to form the reclosable bag, a dimpling of the film, a scoring of the film, or any other tearing axis known to those skilled in the art. Shown as a plurality of perforated lines, the lines of weakness 80 , 81 align with the perforation axis 19 . The outer edge of the lines of weakness 80 , 81 should be in proximity to the longitudinal edges 24 , 82 of the film, but should also allow a sufficient buffer between the longitudinal edges to prevent the film from tearing to the lines of weakness from the longitudinal edges during the manufacturing process.
Using the bag forming process described in FIGS. 2A and 3A , a bag with the fin seal 35 is shown in FIGS. 7A and 7B . When the wall sections 28 and 30 are folded to form the fin seal 35 , more than half of the lines of weakness 80 should be on the side margin 25 with any remainder on the adjacent wall section 28 . Similarly, more than half of the line of weakness 81 should be on the side margin 26 preferably in alignment with the line of weakness 80 .
In FIG. 8 , the thermoplastic film is formed into a reclosable bag by the form-fill and seal machine. The wall sections 28 and 30 are sealed to the upper flange 36 while preferably avoiding pressure on the perforation axes 19 and 20 . Alternatively, the line of weakness 81 can be applied on the wall section 30 and the side margin 26 after the fin seal is formed, instead of at the stage of manufacturing described earlier. The bottom cross-seal and the top cross-seal 39 are then formed, thereby creating the reclosable bag 38 .
To assist in reaching the perforations of the reclosable bag 38 during an opening operation, the tear notch 50 is formed by cutting or melting away material from an edge of the reclosable bag 38 . If a seal is necessary for the notch 50 , a melting operation is used to form the notch. The peripheral melt zone 56 would join the front and rear walls of the package around the notch.
FIG. 9 depicts the reclosable bag 38 in an opening condition. The notch 50 is separated by a tearing force produced by the user, allowing the tearing force to continue to a resultant perforation 57 of the bag. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced by the lines of weakness 80 , 81 , since the lines of weakness produce a weakened layer of the fin seal 35 .
A third embodiment of the present invention is shown in FIG. 10 . In the figure, a line of weakness 84 is created on side 21 of the film 10 with the line of weakness 84 less than half the length of the line of weakness 80 . Additionally, a line of weakness 86 with a length less than half the length of the line of weakness 81 is created on side 22 of the film 10 . Similar to the placements of lines of weakness 80 , 81 , the lines of weakness 84 , 86 align with the perforation axes 19 and 20 .
Using the bag forming process described for FIGS. 2A and 3A , a bag with the fin seal is shown in FIG. 11 . When the wall sections are folded to form the fin seal 35 , lines of weakness 84 , 86 should be fully on the fin seal with the lines of weakness ending short of the fold line 52 and with the lines of weakness preferably in alignment with each other. This positioning of the lines of weakness 84 , 86 allows the resultant reclosable bag to be hermetically sealed since the lines of weakness are not on any bag wall.
In FIG. 12 , the thermoplastic film for forming the bag is folded into a tube by the form-fill and seal machine. The wall sections 28 and 30 are sealed to the upper flange 36 while preferably avoiding pressure on the perforation axes 19 , 20 . Alternatively, the line of weakness 86 can be applied in the side margin 26 after the fin seal is formed, instead of at the stage of manufacturing described earlier. The bottom cross-seal and the top cross-seal 39 are then formed, thereby creating the reclosable bag 38 . To assist in reaching the perforations, the tear notch 50 is formed by cutting or by melting away material from an edge of the reclosable bag 38 . A melting operation is used to form a hermetic seal for the notch. The peripheral melt zone 56 joins the front and rear walls of the package around the notch and hence seals the contents of the interior of the reclosable bag 38 from exposure via the notch.
FIG. 13 depicts the reclosable bag 38 in an opening condition. The notch 50 is separated by a tearing force produced by the user, allowing the tearing force to continue to the resultant perforation 57 of the bag. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced by the lines of weakness 84 , 86 as the tearing force encounters the weakened layers of the fin seal 35 .
A fourth embodiment of the present invention is shown in FIG. 14 . In the figure, the aperture 23 is cut or punched through the thermoplastic film 10 on the side 21 such that the longitudinal axis of the aperture aligns to an area to the right of and parallel with the fastener strip 14 . The outer edge of the aperture 23 should be in proximity to the longitudinal edge 24 of the film, but should allow a sufficient buffer between the longitudinal edge to prevent the film from tearing to the aperture 23 from the longitudinal edge during the manufacturing process.
Using the bag forming process described in FIGS. 2A and 3A , a bag with the fin seal 35 is shown in FIG. 15 . When the wall sections 28 , 30 are folded to form the fin seal 35 , more than half of the aperture 23 should be on the side margin 25 with the remainder on the adjacent wall section 28 . A cross-jaw sealing section of a form-fill and seal machine (not shown) seals the wall sections 28 , 30 to an upper flange 36 of profile strip 18 of the fastener strip 14 .
In FIG. 16 , the thermoplastic film for forming the bag is folded into a tube with the fin seal 35 sealed to wall section 28 . Because of the removed layers of the wall section 28 created by the aperture 23 , the fin seal margin 26 now seals directly to the thermoplastic film 10 of the interior bag wall 87 above the fastener strip 14 . The thermoplastic film is now formed as a reclosable bag 38 by forming the bottom seal and the top cross-seal 39 .
To assist in reaching the perforations of the reclosable bag 38 during an opening operation, the tear notch 50 is formed by cutting or melting away material from an edge of the reclosable bag 38 . If a seal is necessary for the notch 50 , a melting operation is used to form the notch. A peripheral melt zone 56 would join the front and rear walls of the package around the notch and hence would seal the contents of the interior of the reclosable bag from exposure via the notch. As shown in FIG. 17 , the alternative tear notch 51 may be formed by cutting or melting away material from the top cross-seal 39 . For the tear notches 50 and 51 , the edge selected should be closest to the fold line 52 .
FIG. 18 depicts the reclosable bag 38 in an opening condition. The notch 50 is separated by a tearing force produced by the user, thereby allowing the tearing force along the top of the fastener 14 to the aperture 23 . The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and thereby prevents the package from being destroyed. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced since the tearing force is exposed to only the side margin 26 of the fin seal. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
FIG. 19 depicts the reclosable bag 38 in an alternative opening condition using the tear notch 51 . The notch 51 is separated by a tearing force produced by the user, thereby allowing the tearing force to proceed along the top of the fastener 14 to the aperture 23 . The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and prevents the package from being destroyed. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced since the tearing force is exposed to only the side margin 26 of the fin seal. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
A fifth embodiment of the present invention is shown in FIG. 20 . In the figure, the lines of weakness 80 , 81 align to an area to the right of and parallel with the fastener strip 14 . The lines of weakness 80 , 81 should be in proximity to the longitudinal edges 24 , 82 of the film, but should also allow a sufficient buffer between the longitudinal edges to prevent the film from tearing to the lines of weakness from the longitudinal edges during manufacture.
Using the bag forming process described in FIGS. 2A and 3A , a bag with the fin seal 35 is shown in FIG. 21 . When the wall sections 28 and 30 are folded to form the fin seal 35 , more than half of the line of weakness 80 should be on the side margin 25 with the remainder on the adjacent wall section 28 . Similarly, more than half of the line of weakness 81 should be on the side margin 26 preferably in alignment with the line of weakness 80 .
In FIG. 22 , the thermoplastic film for forming the bag is folded into a tube with a fin seal 35 by the form-fill and seal machine. The wall sections 28 and 30 are sealed to the upper flange 36 . Alternatively the line of weakness 81 can be applied in the side margin 26 after the fin seal 35 is formed, instead of at the stage of manufacturing described earlier. The bottom cross-seal and the top cross-seal 39 are formed, thereby creating the reclosable bag 38 .
To assist in reaching the perforations of the reclosable bag 38 during an opening operation, the tear notch 50 is formed by cutting or melting away material from an edge of the reclosable bag 38 . If a seal is necessary for the notch 50 , a melting operation is used to form the notch. A peripheral melt zone 56 would join the front and rear walls of the package around the notch 50 and hence would seal the contents of the interior of the reclosable bag from exposure via the notch. As shown in FIG. 23 , the alternative tear notch 51 may be formed by cutting or melting away material from the top cross-seal 39 .
FIG. 24 depicts the reclosable bag 38 in an opening condition. The notch 50 is separated by a tearing force produced by the user, thereby allowing the tearing force along the top of the fastener 14 to the lines of weakness 80 , 81 . The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and thereby prevents the package from being destroyed. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced since the tearing force is exposed to the lines of weakness. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
FIG. 25 depicts the reclosable bag 38 in an alternative opening condition using the tear notch 51 . The notch 51 is separated by a tearing force produced by the user, thereby allowing the tearing force along the top of the fastener 14 to the lines of weakness 80 , 81 . The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and thereby prevents the package from being destroyed. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced since the tearing force is exposed to the lines of weakness 80 , 81 on the fin seal. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
A sixth embodiment of the present invention is shown in FIG. 26 . In the figure, a line of weakness 84 is created on side 21 of the film 10 with the line of weakness less than half the length of the line of weakness 80 . Additionally, a line of weakness 86 with a length less than half the length of the line of weakness 81 is created on side 22 of the film 10 . Similar to the lines of weakness 80 , 81 in FIG. 20 , the lines of weakness 84 , 86 in FIG. 26 align to an area to the right of and parallel with the fastener strip 14 .
Using the bag forming process described for FIGS. 2A and 3A , a bag with the fin seal 35 is shown in FIG. 27 . When the wall sections are folded to form the fin seal 35 , lines of weakness 84 , 86 should be fully on the fin seal with the lines of weakness ending short of the fold line 52 and preferably in alignment with each other. This allows the resultant reclosable bag to be hermetically sealed since the lines of weakness 84 , 86 are not on any bag wall.
In FIG. 28 , the thermoplastic film for forming the bag is folded into a tube by the form-fill and seal machine. The wall sections 28 and 30 are sealed to the upper flange 36 . The bottom cross-seal and the top cross-seal 39 are formed, thereby creating the reclosable bag 38 . Alternatively, the line of weakness 86 can be applied on the side margin 26 after the fin seal is formed instead of at the stage of manufacturing described earlier.
To assist in reaching the perforations, the tear notch 50 is formed by cutting or melting away material from an edge of the reclosable bag 38 . If a hermetic seal is necessary for the notch 50 , a melting operation is used to form the notch. The peripheral melt zone 56 would join the front and rear walls of the package around the notch and hence would seal the contents of the interior of the reclosable bag from exposure via the notch. As shown in FIG. 29 , the alternative tear notch 51 may be formed by cutting or melting away material from the top cross-seal 39 .
FIG. 30 depicts the reclosable bag 38 in an opening condition. The notch 50 is separated by a tearing force produced by the user, allowing the tearing force to continue to the fin seal 35 of the bag along the top of fastener strip 14 . As the tearing force proceeds, the hindrance of the fin seal 35 is reduced by the lines of weakness 84 , 86 since the tearing force encounters a weakened layer of the fin seal 35 . The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and prevents the package from being destroyed. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
FIG. 31 depicts the reclosable bag 38 in an alternative opening condition using the tear notch 51 . The notch 51 is separated by a tearing force produced by the user, thereby allowing the tearing force to continue along the top of the fastener 14 to the lines of weakness 84 , 86 . As the tearing force proceeds, the hindrance of the fin seal 35 is reduced since the tearing force encounters a weakened layer of the fin seal. The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and prevents the package from being destroyed. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
FIG. 32 depicts another alternative tear notch 100 formed in the top cross-seal 39 by cutting or melting away material in the cross-seal. FIG. 33 depicts the reclosable bag 38 in another alternative opening condition using the tear notch 100 . The notch 51 is separated by a tearing force produced by the user, thereby allowing the tearing force to continue along the top of the fastener 14 to the lines of weakness 84 , 86 . As the tearing force proceeds, the hindrance of the fin seal 35 is reduced since the tearing force encounters a weakened layer of the fin seal. The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and prevents the package from being destroyed. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
Although the tear notch 100 is shown for the sixth embodiment of the present invention, the tear notch may be formed in the cross-seal 39 for the fourth and fifth embodiments of the present invention. The separation of the notch 100 , as described for FIG. 33 , would be similar for the areas of weakness described for the fourth and fifth embodiments.
Thus, the several aforementioned objects and advantages are most effectively attained. Although preferred embodiments of the invention have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.
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A method of making a reclosable plastic bag ( 38 ) having a fin seal ( 35 ) which provides a weakness area ( 23, 80, 81, 84, 86 ) that extends into at least one side of the fin seal ( 35 ). Perforation axes ( 19, 20 ) for opening the reclosable plastic bag ( 38 ) may be aligned with the weakness area ( 23, 80, 81, 84, 86 ). A reclosable bag ( 38 ) made in accordance with the method is also disclosed.
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FIELD OF THE INVENTION
[0001] This invention relates to electrosurgery generally and more specifically to an electrosurgical instrument.
BACKGROUND
[0002] Electrosurgery is a well known technology utilizing an applied electric current to cut, ablate or coagulate human or animal tissue. See U.S. Pat. No. 7,789,879 issued to Daniel V. Palanker et al., incorporated herein in its entirety by reference. Typical electrosurgical devices apply an electrical potential difference or a voltage difference between a cutting electrode and a portion of the patient's grounded body in a monopolar arrangement or between a cutting electrode and a return electrode in bipolar arrangement, to deliver electrical energy to the operative field where tissue is to be treated. The voltage is applied as a continuous train of high frequency pulses, typically in the RF (radio frequency) range.
[0003] The operating conditions of electrosurgical devices vary, see the above-referenced patent, in particular a configuration of the cutting electrode is described there whereby a conductive liquid medium surrounding the electrode is heated by the applied electric current to produce a vapor cavity around the cutting portion of the electrode and to ionize a gas inside a vapor cavity to produce a plasma. The presence of the plasma maintains electrical conductivity between the electrodes. The voltage applied between the electrodes is modulated in pulses having a modulation format selected to minimize the size of the vapor cavity, the rate of formation of vapor cavity and heat diffusion into the material as the material is cut with an edge of the cutting portion of the cutting electrode.
[0004] The operating principle thereby is based on formation of a thin layer of a plasma along the cutting portion of the cutting electrode. Typically some sort of conductive medium, such as saline solution or normally present bodily fluids, surround the cutting portion of the electrode such that the liquid medium is heated to produce a vapor cavity around the cutting portion. During heating an amount of the medium is vaporized to produce a gas inside a vapor cavity. Since typically the medium is saline solution or bodily fluids, the gas is composed primarily of water vapor. The layer of gas is ionized in the strong electric field or on the cutting electrode to make up the thin layer of plasma. Because the plasma is electrically conductive, it maintains electrical conductivity.
[0005] The energizing electrical energy modulation format in that patent includes pulses having a pulse duration in the range of 10 microseconds to 10 milliseconds. Preferably the pulses are composed of minipulses having a minipulse duration in the range of 0.1 to 10 microseconds and an interval ranging from 0.1 to 10 microseconds between the minipulses. Preferably the minipulse duration is selected in the range substantially between 0.2 and 5 microseconds and the interval between them is shorter than a lifetime of the vapor cavity. The peak power of the minipulses can be varied from minipulse to minipulse. Alternately, the minipulses are made up of micropulses where each micropulse has a duration of 0.1 to 1 microsecond.
[0006] Preferably the minipulses have alternating polarity, that is exhibit alternating positive and negative polarities. This modulation format limits the amount of charge transferred to the tissue and avoids various adverse tissue reactions such as muscle contractions and electroporation. Additional devices for preventing charge transfer to the biological tissue can be employed in combination with this modulation format or separately when the method is applied in performing electrosurgery. This pulsing regime is not limiting.
[0007] Typically the temperature of the cutting portion of the electrode is maintained between 40 and 1,000° C.
[0008] That patent also describes particular shapes of the electrode and especially its cutting portion in terms of shape and dimensionality. Such electrosurgical devices provide several surgical techniques, including cutting, bleeding control (coagulation) and tissue ablation. Typically different types of electrodes and energizing formats are used for various purposes since the amount of energy applied and the type of tissue being worked on differ depending on the surgical technique being used.
[0009] Further, it is known in the field for a single electrosurgery hand piece to have detachable electrodes, such as for instance a cutting electrode and a coagulation electrode. At any one time, only a single electrode is attached to the hand piece, see U.S. Pat. No. 5,984,918 issued to Garito et al. where multiple sized electrosurgical electrodes are connected to a handle using a collet member.
[0010] Therefore a known technical problem is that during a surgical procedure, the surgeon must switch between various types of electrosurgical equipment, at least by changing the electrode type. This is typically done by swapping between various electrodes either by changing the electrode portion applied to the body as in Garito et al., or by using entirely different sets of equipment for cutting and coagulation or ablation.
[0011] It has been found by the present inventors that this is undesirable and a better system would provide several types of surgical techniques using a single electrosurgical apparatus.
SUMMARY
[0012] An apparatus for electrosurgery in accordance with the invention has been found to reduce operating time, increase ease of use of the equipment, and combine several surgical techniques in one device, including especially cutting and coagulation. In surgery, typically cutting of tissue in the operative field is followed by coagulation of the remaining tissue in the resulting wound to prevent bleeding. Coagulation generally refers to heating the tissue surface so as to seal off small severed blood vessels that would otherwise leak blood into the wound. Coagulation is necessary to prevent blood loss and also because blood leaking into the wound obscures the surgeon's view of the operative field.
[0013] The present electrosurgical apparatus provides what is referred to as single instrument surgery and carries out both precision resection (cutting) as well as enhanced coagulation (bleeding control). A typical use is in transcolation, for joint replacement surgery. In some embodiments, this apparatus includes an integrated feature to suck out blood, fluids, smoke, etc. from the operative field to keep the operative field clear, or to supply fluid such as saline solution to the operative field.
[0014] In one embodiment the present apparatus includes a hand unit which is mostly conventional for grasping by the surgeon, and which is conventionally coupled at its proximal portion by an electric cable to a control unit which provides the energizing electric pulses or current. The hand unit includes controls including at least one switch or button. The hand unit terminates at its distal portion in a conventional electrosurgical blade (electrode) which is intended for a first electrosurgical procedure such as the cutting (dissection) of tissue, thereby forming the primary assembly. In one embodiment, this electrode is a conventionally shaped electrosurgical blade intended for cutting soft tissue and is typically of metal most of the surface area of which is electrically insulated such as by a thin layer of glass.
[0015] The type of electrical energy applied to this blade by the control unit is, e.g., as described in the above-referenced patent so as to provide plasma type conditions at the electrode tip for tissue cutting, but this is not limiting. In one embodiment, this blade has a 3.0 mm wide spatula shaped tip mounted on a variable length (extendable) shaft. An example is in the PEAK PlasmaBlade® 3.05 surgical instrument supplied by PEAK Surgical, Inc., of Palo Alto, Ca. which has a telescoping electrode shaft and a spatula shaped electrode tip which is 3 mm wide, and an integrated aspiration feature. This device includes the hand unit.
[0016] In one embodiment, the present apparatus is a monopolar type cutting device (like the PEAK PlasmaBlade instrument) whereby the return current path is via a grounding pad or other return electrode affixed to the patient's body remote from the electrosurgical instrument. In other embodiments, the present apparatus is a bipolar type where the return electrode is located on or near the main electrode and is an integral part of the electrosurgical apparatus, as also well known in the field.
[0017] The secondary assembly of the present apparatus, in one embodiment, is intended for a second electrosurgical procedure such as tissue coagulation. It terminates at its distal portion in its own electrode blade or tip which in one case is hemispherical (ball shaped) and which is the distal end of an electrode shaft which is at least partially insulated. The proximate portion of the electrode shaft terminates in a housing which fits closely around the electrode shaft and provides heat and electrical insulation and a finger grip region. However, the housing itself is not intended to be held by the surgeon when the apparatus is in use. Instead, this housing fits snugly over the electrode blade of the primary assembly so that the electrode of the primary assembly also makes electrical contact with the electrode shaft of the secondary assembly. The electrical energy (pulsing) or continuous wave regime applied to the electrode of the secondary assembly (via the hand unit) may differ from that supplied to the primary assembly. The selection of the electrical energy regime is conventionally performed by the surgeon by manipulating controls on the control unit or on the hand unit
[0018] For coagulation, the duty cycle regime of the applied electrical energy is, e.g., in the range of 12% to 19%. With associated peak to peak voltages in the range of 1300 to 5000 volts, the coagulation effect can be achieved using the electrode of the secondary assembly with conventional settings of the associated pulse generator of “cut”, “coagulation” or “blend.” Since the surface area of this coagulation electrode is large with respect to the applied voltage, the effect is resistive heating of the tissue rather than plasma generation that would ablate (cut) the tissue. For coagulation, generally the electrode is heated to about 100° C. so as to heat fluids in the tissue so the tissue in contact with the active portion of the electrode desiccates or stops bleeding:
[0019] When the secondary assembly is thus mounted to the primary assembly, the apparatus is suitable for coagulation since the primary assembly's electrode blade is now hidden and only serves as a mechanical mounting and electrical connection to the electrode of the coagulation (secondary) assembly. The secondary assembly fits over the distal portion of the primary assembly, e.g., with a snap (friction) fit so the secondary assembly can be readily attached and removed by the surgeon during surgery, without unscrewing or any tool. Thereby the surgeon can quickly switch between cutting and coagulation procedures, with essentially the same apparatus. When the surgeon mounts the coagulation (secondary) assembly to the primary assembly, he also may reset the control unit to supply electrical energy (pulsing or continuous) in the desired modulation regime suitable for tissue coagulation by the coagulation electrode.
[0020] In some embodiments, the two electrodes each carry a non-stick coating on their exposed (non insulated) portions. The coagulation electrode may be a ball, tube, screen, suction coagulator or forceps type electrode. Also the secondary (coagulation) assembly may be provided with a drip chamber near its distal portion or a perforated shaft so as to deliver fluid to the operative field, such as saline, or to provide aspiration. In some embodiments, a conventional channel or other type of passage such as a tube is provided for aspiration of smoke and/or fluid from the wound or fluid delivery. This passage (or passages) may be provided in only the secondary or primary assembly or in both in a fluid communication fashion. In some embodiments, the secondary assembly near its distal portion defines one or more aspiration ports, such as three such ports arranged around the circumference of the assembly and spaced at 120 degrees from one another, all in communication with the aspiration channel.
[0021] In one embodiment, the coagulation assembly's electrode shaft is bendable so that the surgeon can bend it and it remains in the bent position for ease of reaching portions of the operative field. The housing of the secondary assembly defines exterior finger grip ridges (ribs) in one embodiment so as to make it easier for the surgeon to attach and detach it from the primary assembly.
[0022] Therefore the secondary assembly, which in one embodiment is intended for coagulation, attaches to the primary assembly and by making electrical and mechanical contact thereto, conducts the electrical energy originating at the control unit, via the primary assembly electrode, to the tip of the coagulation assembly electrode. The shape of the electrode of the primary assembly is not limited to being a blade, but may take any other typical shape, such as a ball, tube, screen, suction coagulator or forceps. In one embodiment, the mechanical and electrical contact between the two assemblies is maintained at least partly by a spring in the housing of the secondary assembly.
[0023] Further, in other embodiments the functionality of the primary and secondary assemblies is reversed, so the primary electrode is for coagulation and the secondary electrode is for cutting. In other embodiments, the two electrodes have other intended uses in terms of electrosurgical procedures.
[0024] Advantages of the present device include reduced cost in use, since there is no need to supply saline solution to the operative field. This also reduces smoke production, making the surgery easier. Further there is no need for a separate aspiration device, since aspiration is integrated into the device.
BRIEF DESCRIPTION OF THE FIGURES
[0025] FIG. 1 shows an embodiment of the present apparatus as fully assembled, including the coagulation (secondary) assembly and the hand piece and electrode of the primary (main or cutting) assembly.
[0026] FIG. 2 shows the primary assembly separated from the coagulation assembly of FIG. 1 .
[0027] FIG. 3 shows the distal end of the primary assembly, including its cutting electrode.
[0028] FIG. 4 shows an exploded view of the coagulation assembly.
[0029] FIG. 5 shows detail of the coagulation assembly in a cross-sectional view.
[0030] FIG. 6 shows detail of the tip of the coagulation assembly.
[0031] FIG. 7 shows an “X-ray” view of the distal end of the primary assembly and the proximal end of the coagulation assembly.
DETAILED DESCRIPTION
[0032] FIG. 1 shows an electrosurgical apparatus 10 in accordance with the invention, having two main portions or assemblies. Primary assembly 14 is intended for tissue cutting and includes a conventional hand piece 20 to which is conventionally coupled an insulated electrical cable 22 for providing the energizing electrical current or pulses. Also provided is extension 26 from which extends conventionally a tube or tubes for aspiration and/or providing fluid. These tubes are connected through suitable channels to a distal portion of the primary assembly. Also shown in FIG. 1 is the boot or seal 34 between the hand piece 20 and shaft 38 ; boot 34 is typically of electrically insulative material such as silicone, extending from which is the electrode shaft 38 . Assembly 14 is, e.g., the PEAK PlasmaBlade device as described above. Conventional cut/coagulation control buttons are respectively at 21 , 23 .
[0033] The second portion of the apparatus 10 is the secondary (here a coagulation “cap”) assembly 16 which includes housing 42 including exterior finger grip ridges 46 , and from which extends an insulated shaft 44 terminating in electrode tip 48 . Note that dimensions and materials here are largely conventional, as explained hereinafter.
[0034] FIG. 2 also shows the two assemblies 14 and 16 in a slightly different view, but detached (demounted) from one another. Generally the same reference numbers used in different figures here refer to the same or similar structures. In FIG. 2 , extension portion 38 of the primary assembly is not visible since it is retracted.
[0035] In FIG. 2 , since the two assemblies are shown detached, also visible is the base portion 52 of the primary assembly which in one embodiment has its own grip 52 as described and shown further below. Typically grip 52 is, e.g., of a high durometer (hard) polymer material. Blade 50 extends from an insulated portion 51 .
[0036] In one embodiment, shaft 44 of secondary assembly 16 is bendable. While here assembly 16 has a hemispherical or ball electrode 48 , this electrode may have any other shapes, such as tube, screen or forceps. Moreover, the exposed conductive (non-insulated) portion of electrode 48 may carry a non-stick coating, such as carbon with a protein such as a collagen, or a material such as PTFE or other flouro-polymer. This electrode is metal and glass coated, but the glass defines a large number of voids or micro-cracks which in use define hot spots by increasing the local impedance to the energizing electrical current. So these hot spots are intended to cause arcing and heating. A typical impedance is 50 to 2K ohms. While this glass insulation wears away as a result of the arcing, this is not problematic due to the use of this electrode for only one surgical procedure. A typical thickness of this glass layer is 0.003 to 0.007 inches (0.076 to 0.178 mm).
[0037] In one embodiment, the shaft of the coagulation electrode immediately proximal its tip 48 is surrounded by a drip chamber 49 for supplying fluid to the operative field, supplied via a suitable passage defined through secondary assembly 16 and connecting to a similar passage in the primary assembly 14 . This passage and drip chamber provide, for instance, saline solution to the operative field.
[0038] FIG. 3 shows detail of the distal portion of the primary assembly 14 , including similar structures as in FIGS. 1 and 2 . FIG. 3 also shows in greater detail the grip 52 . Arrow indicator 53 is provided so that the operator, such as a surgeon, has a reference indicator that the shaft 38 extends from the boot 34 . Attachment of the secondary assembly 16 onto the primary assembly 14 is not orientation specific in this embodiment.
[0039] FIG. 4 is an “exploded” view of the coagulation assembly 16 . The ball tip 48 of the electrode is the distal portion of a conventional metal (or similar electrically conductive material) shaft 66 which can be bendable. The outer portion 44 of the shaft here is an electrically insulative tubing, such as plastic, which covers most of the length of conductive shaft 66 . This tubing 44 may be perforated to deliver saline or serve as an aspiration channel for smoke. In other embodiments it is not so perforated. Spring 68 surrounds and contacts the proximal end of shaft 66 , as explained hereinafter. Housing 42 includes two mating portions 42 a and 42 b, each for instance of plastic.
[0040] FIG. 5 shows a cross-sectional view of the coagulation assembly 16 . FIG. 6 shows detail of the tip of the coagulation assembly 16 . As shown, a short distance proximal from ball electrode 48 , aspiration port 67 is defined in the shaft 66 and its outer portion 44 , for passage of smoke, blood, etc. into an interior channel defined in shaft 66 , in this embodiment. There are for instance three such ports disposed around shaft 66 , equally spaced apart circumferentially. A typical diameter of the ball electrode is 0.18 inches (4 mm) and the port diameter is typically 0.06 inches (1.5 mm). The outer shaft 44 is electrically and heat insulative, for instance made of plastic, and is typically 0.10 inch (2.5 mm) thick. Some of this insulation extends into the port 67 , to prevent debris build up in the port.
[0041] FIG. 7 shows in a “X-ray” view how primary assembly 14 mates with coagulation assembly 16 . Again, the reference numbers refer to the same structures as in the other figures. The two housing halves 42 a, 42 b of the coagulation assembly fit over and engage the grip 52 of the primary assembly 14 . The mating is intended to be finger tight so the two assemblies can be attached and detached with normal hand strength. Spring 68 of coagulation assembly 16 fits over and engages blade 50 of the primary assembly 14 . Arrow indicator 53 on primary assembly 14 points to an associated indicator mark on the exterior of the coagulation assembly housing 42 , as described above. The mating portions of the two assemblies in this embodiment are both rotatably symmetric, so there is no need to align one to the other rotationally.
[0042] Other portions of the present electrosurgical system which are conventional are not shown here. Notably the control unit provides the electric current or pulses as explained above and is of the type well known in the field and is electrically coupled via cable 22 to the present apparatus. An example of such a control unit is the PULSAR® Generator power supply supplied by PEAK Surgical, Inc.
[0043] Also provided, if needed, is a conventional source of fluid and/or a source of vacuum, for aspiration, as well known in the field. Typically the electrically non-conductive portions of the apparatus are polymer or plastic in terms of the housings, tubing, etc. and of conventional materials. The insulative tubing is typically heat shrink or silicone material. The two halves 42 a, 42 b of housing 42 are glued or otherwise fastened together, although in other embodiments, this housing is a single piece of material. As explained above, the coagulation assembly shaft 66 may be of a bendable material, such as a somewhat flexible or annealed metal rod such as, for instance, stainless steel and has a typical diameter of 0.5 to 2 mm.
[0044] Typically the two electrodes are single use (disposable) so as to be used for only a single surgical operation. In particular the entire coagulation subassembly 16 is typically disposable. In terms of the primary assembly 14 , the entire assembly is also disposable, or at least its distal portions including the electrode and its shaft are disposable and detachable from the hand piece which then may be reusable.
[0045] As described above, the exposed (non-insulated) electrode tips of both the primary assembly and the coagulation assembly in one embodiment carry a non-stick coating. These coatings in one embodiment are conventional polymers or flouro-polymers. In another embodiment they are diamond like carbon which conventionally is one of several forms of an amorphous carbon material formed by deposition.
[0046] In other embodiments, the electrode tip coatings are carbon together with a collagen or other protein. For instance this coating may be carbon graphite with a protein or albumin binder. The thickness of the carbon coating on the metal (or other conductive material) surface of the electrode, as needed to support an electrical discharge, is in the range of 10 μm to 1 mm. Conventional carbon sputtering provides only a thickness of 0.1 μm, which is inadequate. A pyrolitic carbon deposition method is known from Morrison, Jr. U.S. Pat. No. 4,074,710 incorporated herein by reference in its entirety, forming carbon on an electrode by burning carbohydrate-containing materials deposited on the electrode.
[0047] The present coating process is different and first involves providing a mixture of carbon or graphite powder (of any convenient particle size) and a binder. The mixture is 1% to 50% powdered carbon or graphite (by weight or volume), preferably about 30% by volume. The binder is a solution of a protein or similar material such as albumin, gelatin, collagen or other biocompatible material in water or other solvent. For instance, the binder may be a 35% solution by volume of albumin in saline solution.
[0048] The bare electrode is briefly dipped into the mixture. The coated electrode is then air dried for, e.g., one minute to one hour at an ambient temperature of 200° C. to 300° C., or until all the solvent has evaporated. Then the coated electrode is placed in an oven for a few seconds to an hour, at a temperature of 200° C. to 600° C. E.g., this baking step takes 5 minutes at 300° C. (Note that the drying and baking can be combined into one step.)
[0049] The electrode is then cooled in the air and ready for assembly with the associated components of the apparatus.
[0050] This disclosure is illustrative and not limiting. Further modifications will be apparent to those skilled in the art in light of this disclosure, and are intended to fall within the scope of the appended claims.
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An electrosurgical apparatus includes two assemblies, one of which is the primary assembly intended for a first surgical procedure, such as cutting tissue, and a secondary assembly intended for a second type of electrosurgical procedure, such as tissue coagulation. The secondary assembly fits over the electrode tip of the primary assembly and makes electrical contact with the electrode tip of the primary assembly. This allows for single instrument surgery whereby the secondary (coagulation) assembly provides bleeding control after the primary assembly has cut tissue. This combination significantly reduces operating time. The secondary assembly has a snap fit over the primary assembly so that it may be readily attached and detached several times during any surgical procedure, as the surgeon alternates between cutting tissue and coagulating the resulting incisions using the apparatus.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention (Technical Field)
[0002] The present invention is a new stable pharmaceutical composition that is suitable for use as an antihypercholesterolemic or antihyperlipidemia agent, and more particularly, a stable pharmaceutical composition containing as an active substance an HMG-CoA reductase inhibitor.
[0003] 2. Description of Related Art
[0004] Fluvastatin, lovastatin, pravastatin, simvastatin, mevastatin, atorvastatin, and cerivastatin, and derivatives, analogs and pharmaceutically acceptable salts thereof, are known as HMG-CoA reductase inhibitors. They are used as antihypercholesterolemic and antihyperlipidemia agents in humans, and are generally produced by fermentation using microorganisms belonging to any one of the Aspergillus, Monascus, Nocardia, Amycolatopsis, Mucor or Penicillium genus. Some of these inhibitors are obtained by treating the fermentation products using the methods of chemical synthesis (as in the case of simvastatin) or they are the products of total chemical synthesis (as in the cases of fluvastatin, atorvastatin and cerivastatin). Some of these are available as a base (such as lovastatin, simvastatin, mevastatin and cervistatin) while others are available as a salt to improve their aqueous solubility (for example, pravastatin atorvastatin and fluvastatin).
[0005] HMG-CoA reductase inhibitor stability in an acidic environment is one of a number of problems associated with such compounds, particularly when in the form of pharmaceutically acceptable salt thereof. For example, the degradation kinetics of fluvastatin in an aqueous solution at various pH are illustrated in FIG. 1 .
[0006] FIG. 1 illustrates the instability of fluvastatin, and by analogy other HMG-CoA reductase compounds, which is directly related to the acidity of the surrounding environment. This instability is due to the extreme lability of the beta and delta-hydroxy groups on the heptenoic acid chain and the presence of a double bond, such that at neutral to acidic pH, the compounds readily undergo any one of elimination, isomerization or oxidation reactions to form conjugated unsaturated aromatic compounds, as well as threo isomers, corresponding lactones, and other degradation products.
[0007] U.S. Pat. No. 5,356,896 to Kabadi et al. discloses a stabilized pharmaceutical composition for HMG-CoA reductase inhibitors which is achieved by maintaining an alkaline environment at the site of dissolution in order to stabilize the pharmaceutical composition, so that the aqueous dispersion of the pharmaceutical formulation reaches a pH of at least 8, preferably at least 9 and up to about 10. This was achieved by adding a basifying agent, such as magnesium oxide, which imparts a pH above 9 to an aqueous dispersion of the formulation of the active substance.
[0008] However, the local alkaline environment created by the basifying agent at the site of dissolution of the pharmaceutical composition has a negative effect on gastric mucosa. The negative effect is particularly evident for patients with a damaged gastric mucous membrane where the mucosa is not able to create a sufficient acidic environment inside the stomach for normal digestive functioning. This is particularly important in chronic therapies involving HMG-CoA reductase inhibitors.
[0009] Additionally, the Kabadi patent also utilizes an enteric coating for its pharmaceutical preparation using materials that are acidic in nature and require special care to employ, such as a barrier coat with a neutral layer underneath the enteric coating. Furthermore, the enteric coating requires a fluid bed coater, which is expensive, requires highly skilled technology and knowledge and is time consuming to operate.
[0010] As a way of avoiding the negative effect of localized alkaline environments while stabilizing HMG-CoA reductase inhibitors, U.S. Pat. No. 6,680,341 to Kerc disclosed that HMG-CoA reductase inhibitors could be protected from pH-related destabilization by the introduction of a buffering agent to the active ingredient. The buffering agent creates a resistance to a change in the pH level of the local environment at the site of dissolution. This resistance is created by way of ion exchange between the base ions of the buffering agent and the acid ions present at the site of dissolution causing the neutralization of the acid ions rather than permitting the acid ions to destabilize the active ingredient.
[0011] However, the presence of an artificially increased amount of buffering agent in the gastric system disrupts the body's natural regulatory changes in pH. Such disruption negatively affects the absorption of drugs in the body.
[0012] Therefore, in order to achieve suitable dosage forms comprising HMG-CoA reductase inhibitors, it is desirable to adequately protect the active ingredient against pH-related destabilization while avoiding the negative effects of localized alkaline environments at the site of dissolution, the negative effects of an artificially increased amount of buffering agents in the gastric system and avoiding the additional problems presented by the use of an enteric coating.
[0013] Additionally, the heat and light sensitivity, as well as the hygroscopicity of the subject compounds impose particular requirements in the manufacture and storage of pharmaceutical dosage forms, such as specialized moisture protective packaging materials. It is desirable to minimize the problems associated with such manufacture and storage.
SUMMARY OF THE INVENTION
[0014] The present invention is a pharmaceutical composition containing an HMG-CoA reductase inhibitor as an active ingredient, which is protected from destabilization in acidic environments while avoiding the aforementioned negative effects.
[0015] The present invention further provides a process for the preparation of a pharmaceutical composition containing an HMG-CoA reductase inhibitor as an active ingredient which is protected from destabilization in acidic environments while avoiding the aforementioned negative effects.
[0016] The present invention further provides a pharmaceutical composition and a process for its preparation, containing an HMG-CoA reductase inhibitor as an active ingredient which is protected from destabilization in acidic environments while avoiding the additional problems presented by the use of an enteric coating and by the manufacturing and storage requirements.
[0017] According to a preferred embodiment of the present invention, there is provided a pharmaceutical composition containing an HMG-CoA reductase inhibitor as an active ingredient which is stabilized in acidic and other environments. The stabilization of degradation of an HMG-CoA reductase inhibitor is achieved by maintaining a pH above 7.0 for the active ingredient and by protecting the active ingredient against acidic degradation without using any alkaline medium or buffering agents.
[0018] According to another preferred embodiment of the present invention, there is provided the pharmaceutical composition containing an HMG-CoA reductase inhibitor which is protected from premature degradation in the gastric region by utilizing beta-cyclodextrin as an inclusion complexing agent which prevents the dissociation of basic and acidic ions of the molecule of the active ingredient contained within its cavity once the molecule is encapsulated therein.
[0019] According to another preferred embodiment of present invention, there is provided the process for the preparation of a pharmaceutical composition containing an HMG-CoA reductase inhibitor as an active ingredient which is stable in acidic and other environments, overcoming the hygroscopic nature of HMG-CoA reductase inhibitors, thereby providing for the composition in a free flowing powder form aiding in encapsulation and tablet formation without the need for enteric coating or the maintenance of sensitive environmental conditions.
[0020] According to another preferred embodiment of the present invention, there is provided a pharmaceutical composition comprising an HMG-CoA reductase inhibitor, a cyclodextrin, a lubricant and a filler.
[0021] According to another preferred embodiment of the present invention, there is provided a method of preparing pharmaceutical compositions which comprises mixing an HMG-CoA reductase inhibitor compound and a cyclodextrin with water to form a slurry, drying the slurry and mixing the dried slurry with a filler and a lubricant and encapsulating the resulting mixture to form capsules capable of delivering the active ingredient.
[0022] Other features and advantages will be apparent from the specification and claims that describe the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a table indicating the degradation kinetics of fluvastatin in an aqueous solution at various pH levels.
[0024] FIG. 2 is a diagram illustrating the chemical structure of beta-cyclodextrin.
[0025] FIG. 3 is a diagram illustrating the complexation of drugs inside the hydrophobic cavity of beta-cyclodextrin.
[0026] FIG. 4 is a diagram illustrating the equilibrium process describing the interaction between a cyclodextrin and an insoluble drug molecule to form a soluble or insoluble complex.
[0027] FIG. 5 is a graph illustrating the correlation between the percentage of complexed drug and cyclodextrin concentration at various K values.
[0028] FIG. 6 is a table showing the dissolution of sample capsules as compared to a control
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Pharmaceutical compositions containing an HMG-CoA reductase inhibitor that are stable at basic pH levels, that is, pH greater than 7.0, are known. It is also known that higher pH levels yield more stable pharmaceutical compositions containing an HMG-CoA reductase inhibitor and that a pH of at least 8, and more preferably a pH greater than 9, is desired. However, the acidic environment of the stomach rapidly lowers the pH of a pharmaceutical composition containing an HMG-CoA reductase inhibitor to a point below which destabilization occurs.
[0030] In the present invention, pharmaceutical compositions containing an HMG-CoA reductase inhibitor are protected against destabilization in the acidic environment of the stomach by utilizing beta-cyclodextrin as an inclusion complexing agent.
[0031] Complexation is one way to favorably enhance the physicochemical properties of pharmaceutical compounds. It is loosely defined as the reversible association of a substrate and ligand to form a new species. Although the classification of complexes is somewhat arbitrary, the differentiation is usually based on the types of interactions and species involved, e.g., metal complexes, molecular complexes, inclusion complexes, and ion-exchange compounds. Cyclodextrins are classic examples of compounds that form inclusion complexes. These complexes are formed when a “guest” molecule is partially or fully included inside a “host” molecule with no covalent bonding. When inclusion complexes are formed, the physicochemical parameters of the guest molecule are disguised or altered, and improvements in the molecule's solubility, stability, taste, safety and bioavailability are commonly seen.
[0032] Numerous cyclodextrins with different complexing abilities are available. Cyclodextrins are cyclic oligosaccharides containing 6, 7, or 8 glucopyranose units, referred to as alpha, beta or gamma cyclodextrin, respectively. Each glucose unit contains two secondary alcohols at C-2 and C-3, and a primary alcohol at the C-6 position, providing 18-24 sites for chemical modification and derivatization. The chemical structure of beta-cyclodextrin is shown in FIG. 2 .
[0033] The 3-dimensional structure of the parent cyclodextrin provides a cavity, as shown in FIG. 3 , which is hydrophobic relative to an aqueous environment. The sequestration of hydrophobic drugs inside the cavity of the cyclodextrin can improve the drug's solubility and stability in water, the rate and extent of dissolution of the drug:cyclodextrin complex, and the bioavailability of the drug when dissolution and solubility are limiting the delivery. These cyclodextrin properties enable the creation of formulations for insoluble drugs which are typically difficult to formulate and deliver with more traditional excipients.
[0034] Cyclodextrins form inclusion complexes with hydrophobic drugs through an equilibrium process, FIG. 4 , quantitatively described by an association or stability constant (K a:b ), where
K a : b = [ Drug a CD b ] [ Drug ] a [ CD ] b
where a and b represent the molar ratio of the sequestered drug molecule to the cyclodextrin. The magnitude of this associate constant can be used to compare the binding effectiveness of different cyclodextrins. Various complexes with different ratios of drug-to-cyclodextrin molecules can be formed, depending on the type of cyclodextrin used and the size and physicochemical characteristics of the drug molecule. In dilute solutions, or if the drug fits entirely into the cyclodextrin cavity, a 1:1 complex results. However, if the cavity is large enough, two drug molecules may be accommodated, resulting in the formation of a 2:1 complex. Conversely, if the drug is very large, then more than one cyclodextrin molecule might enclose the drug for the formation of 1:2 or higher order complexes. Although each complex has a finite stoichiometry, more than one complex may be formed in a given system. Depending on the method used to determine the association constant, it is possible to obtain a description of the stoichiometry of the complex (a:b).
[0035] Complexation of drugs by cyclodextrins improves their delivery characteristics and does not interfere with their activity because complexation is a rapidly reversible process. In an aqueous solution, drug:cyclodextrin complexes are continually forming and dissociating with lifetimes in the range of milliseconds or less. Although slower dissociation kinetics are seen with stronger binding, the rates are still essentially instantaneous.
[0036] The inclusion complex is resistant to hydrolysis in the acidic environment of the stomach, thus maintaining the active ingredient as a guest within the inclusion complex following oral administration and permitting the active ingredient to pass through the stomach without degradation and destabilization. However, the inclusion complex is not resistant to digestion by enzymes present in the intestinal region, thus causing its breakdown and the release of the active ingredient for absorption. In some cases, the drug is released from the inclusion complex upon dilution with contributions from competitive displacement with endogenous lipophiles binding to plasma and tissue components where drug uptake into tissues is not available to the complex and the beta-cyclodextrin is rapidly eliminated. The effects of dilution are demonstrated in FIG. 5 for complexes with various binding constants. Most drug:cyclodextrin complexes exhibit binding constants in the range of 100-20,000 M 1 and even for the more tightly bound drugs, a 1:100 dilution will reduce the percentage of complexed drug from 100% to 30%. A 1:100 dilution is readily attainable for intravenous products, and upon dilution in the stomach and intestinal contents.
[0037] Dilution is minimal, however, when drugs are administered via other routes such as ophthalmic, transmucosal, and transdermal. Under these conditions, the drug can still be displaced from the cyclodextrin cavity by competing lipophiles, such as triglycerides, cholesterol, bile salts, and other hydrophobic compounds often found in high concentrations at the site of delivery.
[0038] With respect to orally administered dosage forms, in order to protect the active ingredient from degradation in the acidic environment of the stomach, an inclusion complex is formed with beta-cyclodextrin and the active ingredient by creating a slurry with beta-cyclodextrin in water, which forms the cavity structure as seen in FIG. 3 . The active ingredient, which is capable of providing a stable pH greater than 7 and preferably greater than 8, is sequestered inside the cavity upon drying. While sequestered inside the cavity, the active ingredient is protected from degradation in the acidic environment in the stomach due to beta-cyclodextrin's resistance to acidic hydrolization. This allows the composition to pass through the stomach in a stable form to be released in the intestines due to beta-cyclodextrin's affinity to hydrolization by enzymatic processes.
[0039] The active ingredient of the present invention is an HMG-CoA reductase inhibitor, which can be any one of the group of fluvastatin, lovastatin, pravastatin, simvastatin, mevastatin, atorvastatin, cerivastatin, the derivatives, analogs and pharmaceutically acceptable salts thereof. The formulation of the beta-cyclodextrin and the HMG-CoA reductase inhibitor is mixed with relatively neutral pH excipients that act as dilutents or fillers, such as sorbitol or lactose, to make up the weight required to fill a capsule or tablet, and lubricants, such as magnesium stearate or talc, to promote smooth flow of the mixture. Persons skilled in the art will recognize that other dilutents, fillers and lubricants may be suitable.
[0040] The resulting pharmaceutical composition provides an active ingredient that is stable and protected against degradation in the acidic environment of the stomach without creating an alkaline medium or using a buffering agent, thus avoiding the problems created thereby. The resulting pharmaceutical composition also provides an active ingredient that is stable and protected against degradation in the acidic environment of the stomach without the use of enteric coatings, thus avoiding the problems created thereby.
[0041] The pharmaceutical compositions according to the present invention may be prepared as described below.
[0042] A calculated amount of water is transferred into a vessel with a stirrer into which beta cyclodextrin is slowly mixed in. An HMG-CoA reductase inhibitor is added in small lots to avoid the formation of lumps, and the mixture is stirred until at least homogenization. After homogenization, the mixture is dried. The dried mixture is milled and passed through a mesh. The pH of the composition should be more than 7 and preferably greater than 8 for achieving maximum stability. Using a complexation technique with beta-cyclodextrin prevents the degradation of the active ingredient in the gastric media.
[0043] The resulting stabilized composition is then formulated with other excipients, including a filler such as sorbitol, which is freely soluble in water and has a pH between 6.0 and 7.0 in water, and a lubricant, such as magnesium stearate. The final formulation may be prepared in capsule form. The pH of the final composition in water is found to be about 9.4, which provides for stability of the active ingredient inside the dosage form.
[0044] Although the foregoing invention has been described in some detail for purposes of illustration, it will be readily apparent to one skilled in the art that changes and modifications may be made without departing from the scope of the invention described herein.
[0045] The present invention will be further illustrated by means of the following examples. It is to be understood, however, that the invention is not meant to be limited to the details described therein.
EXAMPLE 1
Fluvastatin Capsule 20 mg
[0046] The pharmaceutical composition with the active ingredient of fluvastatin sodium in the form of capsules is prepared as follows. Water and beta-cyclodextrin are mixed to create a slurry. Fluvastatin sodium is added to the slurry and stirred over a period of time. The resulting slurry is then dried and milled. The resulting formulation is mixed with sorbitol and magnesium stearate. The resulting mixture is then put into capsules containing 20 mg of fluvastatin sodium.
1. Fluvastatin sodium equivalent to fluvastatin 21.12 mg = 20 mg 2. Beta cyclodextrin 31.68 mg 3. sorbitol 131.2 mg 4. Magnesium stearate 4.00 mg 5. Purified water q.s 188.00 mg/capsule
EXAMPLE 2
Fluvastatin Capsule 40 mg
[0047] The pharmaceutical composition with the active ingredient of fluvastatin sodium in the form of capsules is prepared as follows. Water and beta-cyclodextrin are mixed to create a slurry. Fluvastatin sodium is added to the slurry and stirred over a period of time. The resulting slurry is then dried and milled. The resulting formulation is mixed with sorbitol and magnesium stearate. The resulting mixture is then put into capsules containing 40 mg of fluvastatin sodium.
1. Fluvastatin sodium equivalent to fluvastatin 42.24 mg = 40 mg 2. Beta cyclodextrin 63.36 mg 3. sorbitol 262.40 mg 4. Magnesium stearate 8.00 mg 5. Purified water q.s 376 mg/capsule
[0048] Sample capsules containing fluvastatin sodium as the active ingredient were prepared according to the above examples and were subject to in vitro dissolution studies. It was found that the comparative in vitro dissolution of the sample capsules with respect to Lescol®, used as a control, was equivalent, as shown in FIG. 6 .
[0049] While the invention has been described and illustrated with reference to certain particular embodiments thereof, those skilled in the art will appreciate that various adaptations, changes, modifications, substitutions, deletions, or additions of procedures and protocols may be made without departing from the invention. It is intended, therefore, that the invention be defined by the scope of the claims that follow and that such claims be interpreted as broadly as is reasonable.
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The present invention relates to pharmaceutical compositions containing an HMG-CoA reductase inhibitor which are protected from destabilization in acidic environments by utilizing an inclusion complexing agent, and further relates to their preparation and to their use in the treatment of hypercholesterolemia and hyperlipidemia.
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TECHNICAL FIELD
[0001] The present invention relates to a gear transmission and particularly, but not exclusively, to a transmission having a plurality of selectable speed ratios provided by respective pairs of gear wheels. Aspects of the invention relate to a gearbox, to a powertrain and to a vehicle.
BACKGROUND
[0002] Gear transmissions are typically used in motor vehicles, and multiple speed ratios allow the engine characteristics to be best matched to the required gradient launch, acceleration, top speed, fuel economy and other well understood factors. Gear pairs are typically in constant mesh, and are engaged and disengaged by synchromesh mechanisms which incorporate dog clutches. Manual selection of the required speed ratio is common, but some gear transmission variants have automated or assisted selection, or have fully automatic speed ratio selection.
[0003] In order to achieve good acceleration and fuel economy, the number of speed ratios have increased in recent years, and for some vehicles as many as eight or more forward speed ratios may be provided. Inevitably, these additional speed ratios tend to increase the size of the transmission, which is problematic for vehicle designers where the available space envelope is restricted. A particular difficulty with in-line transmission (so called North-South alignment) is of ingress into the passenger compartment.
[0004] Another objective of vehicle designers is to design components for a range of vehicles, so a substantially common base component is modified to suit the particular attributes which are required of each vehicle in the range. In one extreme example a common component, such as a vehicle transmission, may be required to serve in both a sports car and a vehicle having off-road capability. The base component may be simple and have features added thereto, or it may be complex and have features deleted.
SUMMARY OF THE INVENTION
[0005] According to an aspect of the present invention there is provided a constant mesh gearbox having a plurality of individually selectable forward speed ratios, and comprising a casing ( 20 ) defining an array of parallel rotational axes ( 31 - 35 ), said axes including an input axis ( 31 ), an output axis ( 35 ) and a plurality of intermediate axes ( 32 - 34 ), and gear pairs for driving between members rotatable on the input axis, the output axis and said intermediate axes, wherein a first shaft ( 12 ) is rotatable on one of said intermediate axes, a second shaft ( 14 ) is rotatable on another of said intermediate axes, said first and second shaft are directly connected by a first gear wheel pair ( 60 , 80 ), a sleeve ( 74 ) is rotatable on said second shaft ( 14 ), and said sleeve and said first shaft are directly connected by a second gear wheel pair ( 75 , 76 ), and
[0006] wherein said sleeve ( 74 ) supports a first gear wheel ( 77 ) for rotation thereon, said first gear wheel ( 77 ) being selectively connectable for rotation with said sleeve, and being in driving engagement with an input shaft ( 11 ) on said input axis ( 31 ).
[0007] In an alternative there may be provided a constant mesh gearbox having a plurality of individually selectable speed ratios, and comprising a casing defining five parallel rotational axes, said axes being respectively an input axis, an output axis and three intermediate axes, and gear pairs for driving between members rotatable on the input axis, the output axis and the intermediate axes.
[0008] The gearbox of the invention may be characterized as being wide and short. A feature of embodiments of the invention is that the input and output axes are not aligned which, in the case of an in-line transmission allows an output axis lower than the crankshaft centre line of the engine; this in turn allows a low floor in the passenger compartment with a comparatively negligible transmission tunnel.
[0009] Embodiments of the invention provide six, seven and eight sequential speed ratios in one direction, and one or two sequential speed ratios in the other direction of rotation. The forward speed ratios are at acceptable steps, in the range 60-75% of the preceding speed ratio, and thus give an appropriate ‘feel’ to the vehicle driver, in use.
[0010] A feature of an embodiment of the inventive transmission is that the six highest speed ratios comprise respective pairs of gear wheels which may be adjusted in diameter to obtain a desired variation in the ratio step from one speed to another.
[0011] In use, one or two speed ratios may be omitted if not required in the vehicle for which the transmission is intended; thus may allow omission of gear wheels and gear selection components if not required for other speed ratios.
[0012] In embodiments of the invention one or two speed ratios may be described as low, and intended for use at low vehicle speeds. By selecting a suitable final drive ratio in a vehicle axle, these low ratios may be suitable for an off-road vehicle.
[0013] An embodiment of the invention provides a transmission in which the higher ratios generally have fewer gear wheels in the gear transmission train than the lower ratios, and thus less risk of gear noise at high vehicle speeds. Thus in an eight forward speed embodiment, the highest six ratios have fewer gear wheels in the transmission train than the lowest two ratios.
[0014] A feature of an embodiment of the invention is a sleeve rotatable on an intermediate shaft.
[0015] In one aspect there is provided a constant mesh gearbox having a plurality of individually selectable forward speed ratios, and comprising a casing defining an array of parallel rotational axes, said axes including an input axis, an output axis and a plurality of intermediate axes, and gear pairs for driving between members rotatable on the input axis, the output axis and said intermediate axes, wherein a first shaft is rotatable on one of said intermediate axes, a second shaft is rotatable on another of said intermediate axes, said first and second shaft are directly connected by a first gear wheel pair, a sleeve is rotatable on said second shaft, and said sleeve and said first shaft are directly connected by a second gear wheel pair.
[0016] The sleeve allows additional gearing options and torque flows within a short transmission.
[0017] Aspects of the gear wheel arrangements are enumerated in the claims appended hereto.
[0018] In an embodiment the sleeve is supported by rolling element bearings adjacent the ends thereof, one of said bearings engaging said casing, and the other of said bearings engaging said second shaft. The other of said bearings is in one embodiment disposed between the second shaft and the second gear wheel, the second gear wheel being journalled on the sleeve.
[0019] According to embodiments of the invention the input axis is not aligned with the output axis, thus permitting a relatively low level output (propeller) shaft for a rear wheel drive vehicle having a conventional north/south engine installation. Such a low level output shaft ensures minimum intrusion into the passenger space of the vehicle. In a front wheel drive vehicle with east/west engine installation, a low level output axis is convenient for drive to the front wheels whilst avoiding excessive angularity of drive shafts.
[0020] A differential gear on the output axis may be provided to give drive to opposite vehicle axles, typically front and rear axles. In one embodiment of the invention drive to one of said axles is on a sixth parallel axis radially outboard of said output axis. Means for driving between the output axis and the sixth axis may include gear wheels or a chain/belt and sprockets. This arrangement provides a low forward drive axis for the front axle of a vehicle, and facilitates passage of the usual propeller shaft past a front mounted engine.
[0021] There may be provided a transmission according to the invention having one or more very low ratios incorporated in a single transmission casing. By very low ratios we mean overall ratios lower than that encountered and vehicle designed solely for highway use, and typically as low as 20:1 and/or with a spread of forward ratios exceeding 15. Such ratios are typically provided by a selectable transfer box of a four wheel drive off-road vehicle.
[0022] Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:—
[0024] FIG. 1 is a schematic elevation of one axial end of a transmission according to an embodiment of the invention;
[0025] FIG. 2 illustrates a variant of the transmission of FIG. 1 from the side and one end;
[0026] FIG. 3 is a developed section through the transmission of FIG. 2 , showing all of the shaft axes in the same plane;
[0027] FIG. 4 is an enlarged view of the upper part of FIG. 3 ;
[0028] FIG. 5 is an enlarged view of the lower part of FIG. 3 ;
[0029] FIG. 6 illustrates an example gear shift pattern for a manual variant of the transmission of FIG. 2 ; and
[0030] FIG. 7 is a schematic illustration of a north/south installation of a transmission according to an embodiment of the invention in a four wheel drive vehicle.
DETAILED DESCRIPTION
[0031] A transmission according to an embodiment of the invention is illustrated in FIGS. 1-2 , and comprises five shafts having parallel axes supported for rotation in a transmission casing (not shown). The shafts are identified as input shaft 11 , low speed layshaft 12 , high speed layshaft 13 , reverse layshaft 14 and primary output shaft 15 . A secondary output shaft 16 may optionally be provided on a sixth parallel axis, in particular where drive to two vehicle axles is required. Although termed ‘primary’ and ‘secondary’, the output shafts 15 , 16 may be alone or in combination, and thus a drive connection from either may be omitted if a single driven axis is sufficient. Thus the transmission in a vehicle may provide front wheel drive, rear wheel drive and all wheel drive, in different configurations.
[0032] By ‘high’ and ‘low’ speed layshafts we mean that the shafts are associated with respective higher and lower speed ratios, not that the shafts necessarily have high and low speeds as such.
[0033] The shafts 11 - 15 support pairs of gear wheels in constant mesh, which may be engaged with and disengaged from respective shafts so as to provide drive through the transmission.
[0034] The number and form of teeth on each gear wheel is selected according to well understood parameters and forms no part of this invention as such. The relative diameter of respective pairs of gear wheels is selected to give appropriate speed ratios, and in particular acceptable steps between adjacent ratios, as will become apparent from the following description. Roller and ball bearings are provided to support the shafts within the transmission casing in accordance with well understood principles, and taking into account the torque to be transmitted, thrust loads, bearing life and other conventional factors.
[0035] As illustrated in FIG. 1 drive between primary and secondary output shafts 15 , 16 is by chain or belt 17 , in order to preserve a desired rotational direction. Arrow 18 represents the direction of input torque, whereas arrows 19 represent that output torque may be in either rotational direction (.e. both forward and reverse in a vehicle).
[0036] A feature of the transmission, which will be readily apparent from FIG. 1 , is that the layshafts 12 , 13 and the reverse shaft 14 can directly drive the primary output shaft 15 .
[0037] The disposition of shafts within the transmission casing is as illustrated in FIGS. 1 and 2 . However for the purposes of further explanation, FIG. 3 shows a developed longitudinal section, with all shafts in a common plane. A casing is represented by dotted line 20 in order to show support for respective shaft bearings.
[0038] The main features of the transmission of FIG. 3 are as follows:
[0039] selectable gear pairs are provided between the shafts in four planes;
[0040] a fifth plane is defined at the left side (as viewed) for gear wheels which couple the layshafts 12 and 14 ; and a sixth plane is defined at the right side (as viewed) for gear wheels which directly drive the output shaft 15 ;
[0041] five pairs of double acting gear selectors 21 - 25 are provided, each consisting of dog clutches which typically incorporate conventional synchromesh couplings;
[0042] an all wheel drive variant is illustrated—thus both output shafts 15 , 16 are included, and the primary output shaft 15 includes a differential gear 26 within the transmission casing (the centre differential of a vehicle);
[0043] the low speed layshaft 12 defines a torque path for the low speed ratios 1-4;
[0044] the high speed lay shaft 13 defines a torque path for the high speed ratios 5-6;
[0045] a somewhat conventional reverse ratio is provided via the reverse shaft 14 , in order to reverse the direction of rotation of the output shaft 15 ;
[0046] two additional very low speed ratios, and one additional reverse ratio are provided, as will become apparent;
[0047] the shafts are arranged on parallel axes 31 - 36 . It should be noted that axes 35 , 36 are not co-axial in practice notwithstanding the depiction of FIG. 3 .
[0048] With reference to FIG. 4 , the input shaft 11 protrudes through the transmission casing at the input side 27 , and comprises a male spline 41 for driving connection with the female spline of a driven plate (not shown) of friction clutch; this arrangement is conventional. Rolling element bearings 42 , 43 support the input shaft for rotation in the casing 20 .
[0049] Provided on the shaft for rotation therewith are five gear wheels 44 - 48 . Gear wheels 44 - 47 are respectively associated with forward speeds 2, 1, 4 and 3. As illustrated gear wheel 44 is solid with shaft 11 , whereas gear wheels 45 - 48 slide onto shaft 11 via splines or key ways and are secured in any suitable manner, for example by circlips or the like. Gear wheels 44 - 48 are connected for rotation with the input shaft at all times.
[0050] The low speed layshaft 12 is also supported in the casing 20 by rolling element bearings 52 , 53 at the ends thereof, and includes the mating gears 54 - 57 for forward speed ratios 2, 1, 4, 3.
[0051] Gear wheels 54 , 55 and 57 are each double gears, and consist of side by side gears of different diameter connected for rotation in common. Thus gear wheel 54 has associated gear wheel 58 ; gear wheel 55 has associate gear wheel 59 ; and gear wheel 57 has associated gear wheel 60 . Each double gear may be integrally manufactured from a single blank, or may be an assembly.
[0052] Each of the gear wheels 54 - 57 is freely rotatable in the low speed layshaft 12 , but connectable for rotation herewith by a respective double acting synchromesh selector 21 , 22 . As is well understood, the synchromesh system provides a speed synchronizer and dog clutch for coupling one gear wheel at a time to the respective shaft by right or left movement (as viewed) from an unconnected central position. The selectors 21 , 22 are positioned respectively between gear wheels 54 and 55 and between gear wheels 56 and 57 . Although close together, gear wheels 48 and 60 are not in mesh.
[0053] The higher speed layshaft 13 is supported in the casing 20 by rolling element bearings 62 , 63 and has independently rotatable gear wheels 64 , 65 engaged respectively with gear wheels 46 and 48 of the input shaft 11 . Gear pairs 46 , 64 and 48 , 65 respectively provide forward speed ratios 6 and 5 , and a synchromesh selector 23 is provided to connect one or other gear pair for rotation with the layshaft 13 on demand.
[0054] Both the low speed layshaft 12 and high speed layshaft 13 include output gear wheels 66 , 67 coupled for respective rotation herewith, and which engage with a final drive gear wheel 69 of the output shaft 15 .
[0055] The reverse layshaft 14 is supported in the casing by rolling element bearings 72 , 73 . The reverse layshaft 14 also includes an output gear wheel 68 fast therewith and engaged for rotation with the final drive gear wheel 69 .
[0056] A rotatable sleeve or muff 74 is provided on the reverse layshaft, and is directly connected by transfer gear wheel pair 75 , 76 to the low speed layshaft 12 , as illustrated. This transfer pair is at the input side 27 , whereas the output gears are at the output side 28 ( FIG. 3 ).
[0057] The muff 74 is coaxial with the axis of the reverse layshaft 14 and supports gear wheels 77 , 78 for rotation thereon. These gear wheels 77 , 78 are respectively in mesh with gear wheels 58 , 59 of the low speed layshaft 12 . A double acting synchromesh selector 24 connects the gear wheels 77 , 78 for rotation with the muff 74 on demand.
[0058] The innermost gear wheel 78 is also connectable via one side of synchromesh selector 25 to the reverse layshaft 14 . Rolling element bearings 79 , 81 are provided for the muff 74 as illustrated.
[0059] The other side of the selector 25 is operable to couple a freely rotatable gear wheel 80 of the reverse layshaft 14 to gear wheel 60 of the low speed layshaft 12 .
[0060] The output shaft axis 35 defines the rotational axis of the final drive gear wheel 69 . In the illustrated embodiment the gear wheel 69 is connected to the casing 91 of a conventional differential gear 90 having oppositely directed outputs represented by arrows 92 , 93 .
[0061] In use, suitable drive shafts engaged within the differential gear provide drive to respective forward and rearward vehicle axles, via respective axle mounted differential gears (not shown). Such an arrangement is conventional.
[0062] In the illustrated embodiment, the forward output 92 is connected to a sprocket 94 which drives another sprocket 95 on the secondary output axis 36 of the secondary output shaft 16 ( FIG. 1 ).
[0063] The sprocket 95 is supported in the casing by rolling element bearings 97 , 98 .
[0064] FIG. 2 also illustrates suitable universal drive joints 101 , 102 for coupling the final drive outputs to propeller shafts 103 , 104 associated respectively with front and rear drive axles of a vehicle.
[0065] In the event that only rear wheel drive is required, the differential 90 may be omitted along with the components associated with the front drive output 93 ; the final drive gear 69 is coupled directly to a suitable output shaft for connection to the universal joint 102 .
[0066] In the event that only front wheel drive is required, the differential 90 may be omitted along with components associated with the rear drive output 92 ; the final drive gear 69 is coupled directly to sprocket 94 in any suitable manner, or may directly drive to the universal joint 101 on the same axis.
[0067] The transmission of FIGS. 1-5 provides the following internal speed ratios. In the following description all selectors 21 - 25 are assumed to be in the mid-position (not driving) unless stated otherwise; in this condition the transmission is in neutral.
[0068] Six sequential forward speed ratios are provided, as follows:—
[0069] 1 st
[0070] Selector 21 moved rightward. Drive via input shaft 11 ; gear pair 45 , 55 ; layshaft 12 ; output gears 67 , 69 .
[0071] 2 nd
[0072] Selector 21 moved leftward. Drive via input shaft 11 ; gear pair 44 , 54 ; layshaft 12 ; output gears 67 , 69 .
[0073] 3 rd
[0074] Selector 22 moved rightward. Drive via input shaft 11 , gear pair 47 , 57 ; layshaft 12 ; output gears 67 , 69 .
[0075] 4 th
[0076] Selector 22 moved leftward. Drive via input shaft 11 ; gear pair 46 , 56 ; layshaft 12 ; output gears 67 , 69 .
[0077] 5 th
[0078] Selector 23 moved rightward. Drive via input shaft 11 ; gear pair 48 , 65 ; layshaft 13 ; output gears 66 , 69 .
[0079] 6 th
[0080] Selector 23 moved leftward. Drive via input shaft 11 ; gear pair 46 , 64 ; layshaft 13 ; output gears 66 , 69 .
[0081] It will be understood that individual ratios may be adjusted by changing the diameter of a respective gear pair, save that 4 th and 6 th use a common drive gear 46 and are thus inter-dependent. The relative position of axes 31 - 33 permits further adjustment or gear wheel diameter, and thus ratio.
[0082] In one embodiment, the following ratios are provided:
[0083] 3 rd 7.13
[0084] 1 st —17.74 2 nd —10.82 4 th —5.08 5 th —3.75 6 th —2.78
[0085] Two extra low ratios are provided as follows:—
[0086] L1 Selector 24 moved rightward. Drive via input shaft 11 ; gear pairs 45 , 55 and 59 , 78 ; muff 74 ; gear pair 75 , 76 ; layshaft 12 ; output gears 67 , 69 .
[0087] L2 Selector 24 moved leftward. Drive via input shaft 11 , gear pairs 44 , 54 ; 58 , 77 ; muff 74 ; gear pair 75 , 76 ; layshaft 12 ; output gears 67 , 69 .
[0088] The extra low ratios may be adjusted by changing the diameter of the respective gear pair 45 , 59 and 44 , 58 , and by altering the relative position of reverse shaft axis 34 . In this embodiment the gear wheels on the low speed layshaft are idlers.
[0089] In one embodiment, the following further sequential low ratios are provided:
[0090] L1—43.83 L2—27.19
[0091] Thus eight sequential forward speed ratios are provided. It should be noted that movement of the selectors 21 - 24 is compatible with a conventional shift pattern of the multiple ‘H’ type—thus movement of a gear lever in one direction corresponds to leftward selector movement (L2, 2 nd , 4 th , 6 th ) whereas movement in the opposite direction corresponds to rightward selector movement (L1, 1 st , 3 rd , 5 th ).
[0092] A generally conventional reverse ratio is provided by shifting selector 25 rightwards. Drive is via input shaft 11 ; gear train 47 , 60 , 80 ; reverse layshaft 14 ; output gears 68 , 69 . The additional gear in the train reverses rotation of the drive.
[0093] A low reverse ratio is provided by shifting selector 25 leftwards. Drive is via input shaft 11 ; gear train 45 , 59 , 78 ; reverse layshaft 14 ; output gears 68 , 69 .
[0094] In one embodiment, the following sequential reverse ratios are provided:
[0095] R1—35.79 R2—17.6
[0096] The ratio of R2 is substantially the same as 1 st , and thus corresponds to the feel of a conventional manual transmission. This ratio may be adjusted by varying the relative size of gear wheels 60 and 80 .
[0097] The ratio of R1 may be varied by selecting appropriate diameters of gear wheels 59 and 78 .
[0098] The reverse ratios require opposite movement of the selector 25 , and are thus compatible with manual shift pattern of the ‘H’ type. In R2 ratio the gear wheel on the low speed layshaft is an idler. A suitable shift pattern is illustrated in FIG. 6 . Reverse may be provided in any suitable plane, and is illustrated to the right of 5-6; it could alternatively be to the left of L1-L2.
[0099] The transmission thus provides eight forward and two reverse ratios with an acceptable spread of forward ratios, with steps in the range 60-75%.
[0100] It will be understood that a feature of this transmission is that the three layshafts 12 - 14 in driving connection with the output shaft 15 at all times. Thus drive via any of the three layshafts results in the other two layshafts being back driven. The ratios selected in the described embodiment ensure that the speed of individual gear wheels remains within acceptable design limits for conventional engine speeds, for example below 7000 rpm.
[0101] Whilst the transmission of this invention can provide eight forward and two reverse speeds, it need not do so. For example if specified for road use only, a single reverse ratio (R2) may be sufficient, whereas for off-road use both R1 and R2 may be provided. R1 may be omitted by deleting gear wheels 59 and 78 , and making the selector 25 single acting.
[0102] In the same way L1, or L1 and L2 may be omitted for a road use only application. L1 is omitted by deleting gear wheels 59 and 78 (assuming R1 is omitted and L2 retained).
[0103] L2 is omitted by deleting gear wheels 58 and 77 . Since L1 is almost certainly not required if L2 is omitted, gear wheels 59 , 78 and 75 , 76 may also be deleted. In this configuration R1 is almost certainly not required, which results in deletion of the muff 74 along with selector 24 .
[0104] It will of course be understood that a different naming of speed ratios might follow from deletion of 5 th and 6 th (as described above) whilst retaining L1 and L2. Thus the sequential range L1, L2, 1, 2, 3, 4 might be termed 1 st to 6 th . In this configuration the high speed layshaft 13 and its associated selector 23 , gear pairs 46 , 64 and 48 , 65 , and output gear 66 could be deleted.
[0105] Likewise a sequential 6 speed transmission could comprise L2, 1, 2, 3, 4, 5 and a seven speed transmission could comprise L1, L2, 1, 2, 3, 4, 5 or L2, 1, 2, 3, 4, 5, 6. Whilst not all of these combinations may at first sight be considered useful, they are all practicable in the event that packaging constraints will not allow fitting of the eight speed transmission casing envisaged. Thus omission of one or more forward and reverse ratios will permit the casing to more closely follow the remaining envelope of gear wheels and permit a casing of lesser overall size.
[0106] A notable feature of the invention is that the output shaft is not aligned with the input shaft (see FIG. 1 ). Thus the relatively high level input axis 31 associated with a conventional internal combustion engine (by virtue of crankshaft swing) is accompanied by relatively low level output axes 35 , 36 , which may be useful in eliminating intrusion into the passenger accommodation whilst giving propeller shafts which operate through a lesser angle. The arrangement also permits one propeller shaft to pass the engine more easily.
[0107] Yet another feature is integration of the centre differential 26 within the transmission casing at the relatively low level output axes 35 , 36 . Integration ensures that tolerance build-up, which necessarily results from a separate differential in a separate casing, is avoided.
[0108] FIG. 7 shows an in-line engine configuration 110 with attached transmission 111 , front and rear propeller shafts 112 , 113 , front and rear axles 114 , 115 , and wheels 116 .
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A constant mesh gearbox has five parallel rotational axes. The input and output axes are not aligned. Some torque paths are via a sleeve rotatable on a shaft on one of said axes. Up to eight forward speeds are disclosed, with two very low ratios suitable for non-highway travel. The transmission is suitable for two and four wheel drive.
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TECHNICAL FIELD
[0001] The present invention relates in general to display systems, and in particular, to field emission displays.
BACKGROUND INFORMATION
[0002] Carbon nanotubes have been demonstrated to achieve good electron field emission. However, in the prior art, the carbon nanotubes are deposited on the cathode in disorganized positions. FIG. 1 illustrates such a cathode 100 with a substrate 101 and an electrode 102 . Illustrated are carbon nanotubes 103 deposited on electrode 102 in such disorganized positions. As a result of the random organization of the carbon nanotube fibers, the efficiency of the electron emission is impacted to be less than possible.
[0003] Therefore, there is a need in the art for a method of aligning such carbon nanotubes to improve the efficiency of the electron emission therefrom.
SUMMARY OF THE INVENTION
[0004] The present invention addresses the foregoing need by providing a method for aligning carbon nanotubes within a host phase. Once the carbon nanotubes are aligned, the host phase is then subjected to a binding process to make the alignment of the carbon nanotubes permanent. Thereafter, the surfaces of the host phase can be polished resulting in substantially vertically aligned carbon nanotubes within a thin film, which can then be used within a cathode structure to produce a field emission device, including a display.
[0005] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
[0007] [0007]FIG. 1 illustrates a prior art cathode using unaligned carbon nanotubes;
[0008] [0008]FIG. 2 illustrates carbon nanotubes aligned within a host phase;
[0009] [0009]FIG. 3 illustrates binding of the host phase;
[0010] [0010]FIG. 4 illustrates a thin film including vertically aligned carbon nanotubes;
[0011] [0011]FIG. 5 illustrates a field emission device using the thin film of FIG. 4;
[0012] [0012]FIG. 6 illustrates a data processing system configured in accordance with the present invention;
[0013] [0013]FIG. 7 illustrates a flow diagram of a process for aligning carbon nanotubes in accordance with the present invention;
[0014] [0014]FIG. 8 illustrates an alternative embodiment for the present invention;
[0015] [0015]FIG. 9 illustrates an etching step within an alternative embodiment of the present invention;
[0016] [0016]FIG. 10 illustrates another etching step within an alternative embodiment of the present invention;
[0017] [0017]FIG. 11 illustrates application of a metal layer on the host phase; and
[0018] [0018]FIG. 12 illustrates an alternative embodiment of the present invention.
DETAILED DESCRIPTION
[0019] In the following description, numerous specific details are set forth such as specific host phases or display structures, etc. to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details. In other instances, well-known circuits have been shown in block diagram form in order not to obscure the present invention in unnecessary detail.
[0020] Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views.
[0021] The present invention exploits the fact that carbon nanotubes are similar to elongated particles (molecules), which can be placed with a host phase of ordered elongated particles. Such ordered elongated particles could be liquid crystals, ordered metal fibers in a liquid under a magnetic or electric field, geometrically anizotropic particles, anizotropic crystals (elongated) possessing a strong dipole moment, etc. By selecting the size of the nanotubes with respect to the host phase, the present invention aligns the carbon nanotube fibers by aligning the particles of the host phase.
[0022] Referring to FIGS. 2 - 4 and 7 , as an example, the host phase 200 could be a liquid crystal having liquid crystal molecules 205 . The liquid crystal can also include an ultraviolet (UV) curable binder that hardens the liquid crystal when exposed to UV light, as is further discussed below. The host phase may alternatively be a solution of elongated crystals in an isotropic liquid medium (oil). Another alternative host phase would be a long chain of polymer molecules aligned with each other through a mechanical means, such as rubbing. Such “rubbing” is a commonly used process within the liquid crystal art. Such a rubbing process is further discussed below. The carbon nanotubes 204 are disposed within the host phase (step 701 ) and initially will likely be unaligned with each other (not shown) similar to as that shown in FIG. 1. This is done within a container (not shown) between electrodes 202 and 203 . Electrode 203 is grounded while electrode 202 is coupled to a power source 201 . Assume for this example that the liquid crystal molecules are long and heavy (≧500 angstroms). If the nanotubes 204 are approximately 50 micrometers in length, a field of 50-60 volts will align the host molecules 205 and eventually the nanotubes 204 (step 702 ).
[0023] As an alternative, a substrate may be deposited at the bottom of the host phase 200 and above the electrode 203 so that the host phase with the nanotubes is already deposited on a substrate instead of performing the mounting step 705 described below.
[0024] Another means for aligning the host phase is to place the host phase in physical contact with an alignment layer, such as illustrated in FIG. 8. On a substrate 801 , the alignment layer 802 , which can consist of long chain polymers in a semi-solid form are deposited, and then rubbed or combed in one direction to align the polymers in a specified direction. Physical contact of the host phase 803 with the alignment layer 802 aligns the molecules in the host phase in the specified direction, this direction being dependent on many parameters. Alignment of the host phase in the specified direction induces alignment of the nanotubes disposed within the host phase.
[0025] As noted previously, the host phase can contain an ultraviolet (UV) curable binder 302 (or other curable monomers, for example by heat, etc.). By shining an ultraviolet light, for example, on the organized aligned phase 301 , the process produces a solid film of aligned carbon nanotubes 204 . This process is referred to as binding the alignment (step 703 ).
[0026] Thereafter, the solid film can be sliced, for example along dashed lines A and B, and/or one or more of the surfaces polished (step 704 ) to obtain a thin film 400 of organized carbon nanotubes to be used as a cold electron source for field emission applications. Once an electric field is produced, the carbon nanotubes 204 will emit from their ends 401 .
[0027] Referring to FIG. 9, step 704 may also alternatively include an etching phase, whereby a portion of the host phase 901 is etched back without etching the nanotubes. This is possible since the nanotubes are made of a carbon or graphic material that is more resistant to etching. As a result, this process will expose portions of the nanotubes 902 . It should be noted that the etching step can be performed in combination with or alternatively to the polishing process.
[0028] An alternative etching process is illustrated in FIG. 10, whereby a more directional etching process is performed, usually through the use of a mask (not shown), to selectively etch wells 1003 within the host phase 1001 around selected carbon nanotubes 1002 . Again, the result is that portions of the nanotubes 1002 are exposed.
[0029] Another alternative embodiment of the present invention is illustrated in FIG. 12 where the nanotubes 1202 are contacted by a conductive layer 1205 on the bottom side. A conductive layer 1204 is deposited on the top side. Wells 1203 are then etched down into the top side conductive layer 1204 and the host phase 1201 such that the top conductive layer 1204 is electrically isolated from the nanotubes 1202 . Thus, the top conducting layer 1204 can be used as a gate control.
[0030] The exposing of the carbon nanotubes above the host phase can result in a better emission of electrons from the carbon nanotubes.
[0031] As an alternative to providing a conductive layer on the bottom of the host phase, a conductive layer 1103 can be deposited on top of the host phase 1101 after an etching process to expose portions of the nanotubes 1102 . Naturally, the conductive layer is used to produce the electric field for emission of electrons from the carbon nanotubes 1102 .
[0032] Alternatively, the host phase in each of the above embodiments can be doped to make the host phase conducting or semiconducting, thus eliminating the need for a conductive layer.
[0033] This is further shown by the field emission device 500 is FIG. 5. An anode 501 is made of a substrate 502 , an electrode 503 and a phosphor 504 . The cathode 505 includes a substrate 506 , an electrode 507 and the thin film 400 discussed above. Upon the application of electric field, the carbon nanotubes will emit electrons. Any number of gate electrodes or extraction grids 508 , 509 may optionally be implemented.
[0034] Such a field emission device 500 can be used in many applications, such as to produce single cathode pixel elements, to produce large billboard-like displays, or even smaller displays such as for computers. The cathodes may be aligned in strips to produce a matrix-addressable display.
[0035] [0035]FIG. 6 illustrates a data processing system 613 configured to use a display device made from the field emission devices described in FIG. 5, which illustrates a typical hardware configuration of workstation 613 in accordance with the subject invention having central processing unit (CPU) 610 , such as a conventional microprocessor, and a number of other units interconnected via system bus 612 . Workstation 613 includes random access memory (RAM) 614 , read only memory (ROM) 616 , and input/output (I/O) adapter 618 for connecting peripheral devices such as disk units 620 and tape drives 640 to bus 612 , user interface adapter 622 for connecting keyboard 624 , mouse 626 , and/or other user interface devices such as a touch screen device (not shown) to bus 612 , communication adapter 634 for connecting workstation 613 to a data processing network, and display adapter 636 for connecting bus 612 to display device 638 . CPU 610 may include other circuitry not shown herein, which will include circuitry commonly found within a microprocessor, e.g., execution unit, bus interface unit, arithmetic logic unit, etc. CPU 610 may also reside on a single integrated circuit.
[0036] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
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Carbon nanotubes are aligned within a host phase of a material that has molecules that will align under a certain influence. When the host molecules become aligned, they cause the carbon nanotube fibers to also become aligned in the same direction. The film of aligned carbon nanotubes is then cured into a permanent phase, which can then be polished to produce a thin film of commonly aligned carbon nanotube fibers for use within a field emission device.
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FIELD
[0001] The present disclosure relates to fixture drain inserts, and more specifically to inserts that contain one of many trap assemblies for fixture drains.
BACKGROUND
[0002] Water conservation is a major concern in many areas and is likely to become even more important in the future as populations increase resulting in more water consumption. Practicing water conversation on a regular basis has many benefits including saving money both in the short term and long term. In the short term, water conservation saves the consumer money by reducing a consumer's monthly water utility bill. In the long term, consumers save money by postponing, or even preventing, the building of new water supply infrastructures, thereby reducing the per unit cost (or slowing the increase in cost) of water.
[0003] The bathroom is one area where water is often needlessly used. In fact, the largest daily user of water in the commercial establishments is the urinal and in homes is the toilets. To conserve water use, low water use urinals and no-water urinals and other fixtures have been devised. These no-water urinals are not flushed with water each time a person uses the urinal and, in fact, they are not equipped for flushing as they are not connected to a water supply. As the no-water urinal is repeatedly used, most urine is collected in a compartment of the urinal while some passes through the drain. An oily sealing liquid that is immiscible with the urine and is lighter than the urine covers the collected urine. This oily sealing liquid floats on the surface of the urine, serving as a barrier that prevents odors from the urinal from escaping to the environment. Typically, such no-water urinals include a removable cartridge having a top with an opening in communication with the compartment holding an initial water charge that mixes with urine flowing into the compartment through the opening. A stand pipe type drain is in communication with the compartment that allows the compartment to be drained continually to a sewer or other waste disposal system as the compartment is filled with urine. Dry traps using mechanical valve or small p-traps are also used to prevent odor from escaping while still allowing urine to pass.
[0004] A disadvantage of these no-water urinals is that the urinals are specially designed to accept these removable cartridges. For an institution to convert from water-based urinals to no-water urinals requires the complete replacement of the existing water-based urinals. This can be an expensive and time-consuming process.
[0005] It is desirable to provide a fixture drain insert which may be used in present water-based urinals to convert the urinals to low-water or no-water based urinals.
[0006] It is desirable to provide a fixture drain insert which may be used with existing traps and fixtures to permit the passage of used fluids and urine while preventing sewer gas from escaping.
BRIEF SUMMARY
[0007] In at least one embodiment, a fixture drain insert assembly is provided that includes a material module support comprising a bottom surface with a securing component; at least one of a trap housing or trap cover comprising an upper surface with a securing component corresponding to the securing component of the material support module, wherein the trap housing or trap cover further includes a plurality of drain apertures, an inner diameter with an external surface, and an interlocking structure on the external surface of the inner diameter; a valve; a gasket; and a cylindrical housing support comprising a cylindrical body with an open top end, the open top end comprising an interlocking structure and an inner lip on the inner surface of the open top end, wherein the interlocking structure corresponds to and mates with the interlocking structure of the trap housing or trap cover.
[0008] In at least another embodiment, a fixture drain insert assembly is provided comprising a material support module comprising a cover and a bottom configured to secure together to house a material selected from the group consisting of a fragrance material, an enzyme and/or bacteria material, a cleaning material, and combinations thereof, and a female securing component on the bottom surface of the bottom; a trap housing comprising a sloped upper surface containing a plurality of drain apertures and a central male securing component corresponding to the female securing component of the material support module, an inner diameter containing a plurality of interlocking L-shaped protuberances on an outer surface of the inner diameter, and a plurality of pin interlocking structures around an outer surface of the housing; a housing support comprising an open end containing an inner lip and a plurality of protuberances on an inner surface of the open end, wherein the plurality of pin protuberances correspond to the plurality of interlocking L-shaped protuberances on the inner diameter of the trap housing, wherein the L-shaped protuberances of the inner diameter and the pin protuberances of the housing support are configured to matingly join as a bayonet mount, and a cylindrical body; a valve secured between the housing support and the trap housing and projecting to the housing support; and a drain mounting component comprising a plurality of L-shaped interlocking structures corresponding to the pin interlocking structures around the outer surface of the housing, wherein the L-shaped protuberances of the drain mount and the pin protuberances of the trap housing are configured to matingly join as a bayonet mount.
[0009] In at least another embodiment, a fixture drain insert assembly is provided comprising a material support module comprising a cover and a bottom configured to secure together to house a material selected from the group consisting of a fragrance material, an enzyme and/or bacteria material, a cleaning material, and combinations thereof, and a female securing component on the bottom surface of the bottom; a trap cover comprising a sloped upper surface containing a plurality of drain apertures and a central male securing component corresponding to the female securing component of the material support module, an inner diameter containing a plurality of interlocking L-shaped protuberances on an outer surface of the inner diameter, and a plurality of legs; a housing support comprising an open end containing an inner lip and a plurality of protuberances on an inner surface of the open end, wherein the plurality of pin protuberances correspond to the plurality of interlocking L-shaped protuberances on the inner diameter of the trap housing, wherein the L-shaped protuberances of the inner diameter and the pin protuberances of the housing support are configured to matingly join as a bayonet mount, and a ridge; a drain cover skirt secured between the housing support component and the trap cover; a valve secured between the housing support and the trap cover and projecting into the housing support; and a gasket secured in the ridge of the housing support component.
[0010] Other embodiments, aspects, features, objectives and advantages of the hygiene product disposal apparatus and method of use will be understood and appreciated upon a full reading of the detailed description and the claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Embodiments of the fixture drain insert assembly are disclosed with reference to the accompanying drawings and are for illustrative purposes only. The fixture drain insert assembly is not limited in its application to the details of construction or the arrangement of the components illustrated in the drawings. The fixture drain insert assembly is capable of other embodiments or of being practiced or carried out in other various ways. In the drawings:
[0012] FIG. 1 illustrates a perspective view of an embodiment of a fixture drain insert assembly inserted in a urinal;
[0013] FIG. 2 illustrates a perspective view of drain mounting component in a urinal for securing the fixture drain insert assembly shown in FIG. 1 ;
[0014] FIG. 3 illustrates an exploded view of the fixture drain insert assembly;
[0015] FIG. 4 illustrates a side perspective view of the fixture drain insert assembly of FIG. 1 ;
[0016] FIG. 5 illustrates a cross-sectional view of the fixture drain insert assembly taken along the line V-V of FIG. 4 ;
[0017] FIG. 6 illustrates a cross-sectional view of the fixture drain insert assembly inserted in a urinal drain taken along the line VI-VI of FIG. 1 ;
[0018] FIG. 7 illustrates a perspective view of another embodiment of a fixture drain insert assembly inserted in a urinal drain;
[0019] FIG. 8 illustrates an exploded view of the fixture drain insert assembly of FIG. 7 ;
[0020] FIG. 9 illustrates the gasket of the fixture drain insert assembly shown in FIG. 8 ;
[0021] FIG. 10 illustrates a perspective view of the fixture drain insert assembly;
[0022] FIG. 11 illustrates a cross-sectional view of the fixture drain insert assembly taken along the line XI-XI of FIG. 10 ;
[0023] FIG. 12 illustrates a cross-sectional view of the fixture drain insert assembly inserted in a urinal drain taken along the line XII-XII of FIG. 7 ;
[0024] FIG. 13 illustrates a perspective view of the fixture drain insert assembly inserted in a floor mounted urinal;
[0025] FIG. 14 illustrates a cross-sectional view of the fixture drain assembly inserted in a floor mounted urinal taken along the line XIV-XIV of FIG. 13 ; and
[0026] FIGS. 15-20 illustrate alternative embodiments of a fixture drain insert assembly in use with various types of traps.
DETAILED DESCRIPTION
[0027] FIG. 1 illustrates a perspective view of an embodiment of a fixture drain insert assembly 300 with material support module 280 inserted in a urinal 350 . While in the exemplary embodiments described herein, fixture drain insert assembly 300 is described in the context of urinal drains, it is to be understood that fixture drain insert assembly 300 may be used with other fixtures, such as sinks.
[0028] FIG. 2 illustrates a perspective view of urinal 350 with drain mounting component 301 . Drain mounting component 301 fits within the urinal drain and contains interlocking members 302 which engage protuberances 241 of trap housing 240 (see FIG. 4 ) in a bayonet mount style. Other forms of securing trap housing 240 to drain mounting component 301 may be used however, such as threaded structures, friction fit components, and other attachment structures and assemblies known in the art.
[0029] FIG. 3 illustrates an exploded view of the fixture drain insert assembly 300 shown in FIG. 1 . Material support modules 280 comprises cover 282 and bottom 284 which secure together to enclose fragrance or enzyme/bacteria material 290 . In the exemplary embodiment shown, material 290 is a solid block containing a fragrance or enzyme/bacteria or other cleaning agent. In further exemplary embodiments, material 290 could be a gel or liquid.
[0030] Bottom 282 of material support module 280 includes securing component 288 (shown in dashed) on its bottom surface. Securing component 288 connects and secures material support module 280 to trap house 240 . Trap housing 240 has a corresponding securing component 248 at the center of sloped upper surface 245 which engages securing component 288 of material support module 280 . In the exemplary embodiment shown, securing component 248 is a threaded male member which threadingly engages securing component 288 , which is a threaded female member. However, in further exemplary embodiments, material support module 280 and trap housing 240 may secure to each other through any means known in the art. Sloped upper surface 245 is sloped downwardly towards drain apertures 249 which permit the passage of liquid through trap housing 240 and the rest of fixture drain insert assembly 300 .
[0031] The inner bottom surface of trap housing 240 includes an interlocking structure 246 (shown in more detail in FIG. 5 ), which, in the exemplary embodiment described, is a plurality of L-shaped protuberances oriented radially around the outer surface of an inner diameter 247 (not shown) of trap housing 240 . Interlocking structure 246 engages corresponding interlocking structure 226 of housing support 220 . As shown in FIG. 3 , corresponding interlocking structure 226 comprises a plurality of pin protuberances radially configured around the inner surface of open top end 224 . When housing support 220 and trap housing 240 are secured together, open top end 224 slides over inner diameter 247 of trap housing 240 when interlocking structures 246 and 226 of offset relative to each other. Once interlocking structures 246 and 226 are past each other, trap housing 240 and housing support 220 are rotated relative to one another to align interlocking structures 246 and 226 such that the pin interlocking structures 226 are secured against the L-shaped protuberances 246 . This style of joining is called a bayonet mount, which is easy to engage and disengage for quick and easy joining/removal of trap housing 240 from housing support 220 .
[0032] In further exemplary embodiments, any structure, mechanism or combination thereof may be used to join trap housing 240 and housing support 220 . For example, trap housing 240 and housing support 220 could be joined by interlocking threaded components, adhesives or sonic welding. However, using a form of interlocking components, such as the bayonet mount or threads, provides a quick and easy way to remove fixture drain insert assembly 300 components for cleaning, replacement or repair. It also makes accessing the trap and valve easy without having to remove the entire fixture drain insert assembly 300 from the fixture.
[0033] As illustrated in FIG. 3 , housing support 220 also includes a smooth cylindrical body 228 for insertion into a fixture drain. In other embodiments, cylindrical body 228 may be threaded or have a different shape to conform or secure to a given drain/trap style.
[0034] Fixture drain insert assembly 300 also includes elastomer trap 230 which has an open top end 234 configured to sit on inner lip 225 of housing support 220 . Open top end 234 of elastomer trap 230 provides a passage for liquid from trap housing 240 into housing support 220 (and therefore a fixture drain) through flaps 232 . While two flaps 232 are shown, other exemplary embodiments may use more flaps 232 . When urinal drain insert assembly 300 is assembled, the joining of housing support 220 and trap housing 240 secures elastomer trap 230 between them.
[0035] FIG. 4 illustrates a side perspective view of the fixture drain insert assembly 300 . Material support module 280 is assembled and secured to trap housing 240 with sloped upper surface 245 extending beyond material support module 280 . Trap housing 240 has cylindrical outer surface 242 with protuberances 241 for securing in a fixture drain.
[0036] FIG. 5 illustrates a cross-sectional view of the fixture drain insert assembly 300 taken along the line V-V of FIG. 4 . Material support module 280 contains fragrance or enzyme/bacteria material 290 and is secured to trap housing 240 at securing components 248 (on trap housing) and 228 (on material support module 280 ). As illustrated, male securing component 248 is securely threaded into female securing component 288 .
[0037] The mating of interlocking structures 246 (on inner diameter 247 of trap housing 240 ) and 226 on housing support 220 is also shown. Interlocking structures 246 and 226 are aligned to engage one another and connected as in a bayonet mount, described above. Elastomer trap 230 with two flaps 232 is secured between trap housing 240 and housing support 220 . Trap housing 240 also contains gasket 243 which helps create a seal around a fixture drain.
[0038] FIG. 6 illustrates a cross-sectional view of the fixture drain insert assembly 300 inserted in a urinal 350 taken along the line VI-VI of FIG. 1 . Material support module 280 projects into the basin of urinal 350 and is visible. Trap housing 240 is secured within the urinal's drain with sloped upper surface 245 concealed in the drain beneath material support module 280 . Housing support 220 projects downward into the urinal trap with elastomer trap 230 secured between housing support 220 and trap housing 240 .
[0039] In the exemplary embodiment shown, as liquid (i.e., water, urine, etc.) flows enters the urinal basin, the liquid passes through drain apertures 249 of trap housing 240 , through elastomer trap 230 and out housing support 220 . Elastomer trap 230 acts as a one-way valve permitting only the passage of liquid downward through its flaps 232 and preventing the backup of liquid or gas through elastomer trap 230 . Trap housing 240 further prevents gases and liquids from escaping back up the urinal drain.
[0040] FIG. 7 illustrates a perspective view of another embodiment of a fixture drain insert assembly 300 ′ with material support module 280 inserted in a urinal 350 . In the exemplary embodiment shown in FIGS. 7-11 , fixture drain insert assembly 300 ′ is designed to retrofit into any existing fixture drain.
[0041] FIG. 8 illustrates an exploded view of the fixture drain insert assembly 300 ′ of FIG. 7 . Material support module 280 comprises cover 282 and bottom 284 which secure together to house material 290 . In place of trap housing 240 , however, fixture drain insert assembly 300 ′ comprises trap cover 250 which secures to support module 280 through the connection of securing components 288 (on support module 280 ) and 258 (on trap cover 250 ). Like trap housing 240 , trap cover 250 includes an inner diameter 257 which contains an interlocking structure 256 which corresponds to interlocking structure 226 of housing support 220 . Trap cover 250 also contains legs 251 which keep trap cover with drain apertures 259 slightly raised over drain cover skirt 255 . Drain cover skirt 225 is a flexible piece of material that does not interact with most liquids exposed in urinals (such as a polymeric-based material, silicone, thermoplastic elastomers, thermoplastic olefinic elastomers, etc.) which conforms to a fixture surface to seal around a drain. Drain cover skirt 225 functions to further ensure no odor escapes the drain and helps ensure that urine/liquids pass through drain apertures 259 and, ultimately, elastomer trap 230 .
[0042] Fixture drain insert assembly 300 ′ also includes elastomer trap 230 which has two flaps 232 and an open top end 234 which provides passage of liquid from trap cover 250 through housing support 220 and is designed to rest on inner lip 225 of housing support 220 . Housing support has interlocking structure 226 which corresponds to interlocking structure 256 of trap cover 250 and cylindrical body 228 . In the exemplary embodiment shown, cylindrical body 228 includes ridge 221 for seating gasket 210 . Inner edge 211 of gasket 210 secures in ridge 221 to connect gasket 210 to housing support 220 . Gasket 210 creates an odor seal for fixture drain insert assembly 300 ′.
[0043] FIG. 9 illustrates a top view of gasket 210 . Gasket 210 includes a plurality of removable concentric rings, allowing gasket 210 to be sized to any existing drain or trap style and still create a seal to prevent odors from escaping. Gasket 210 also includes drain apertures 218 which permit liquid to flow past gasket 210 if it should leak past drain cover skirt 255 . Gasket 210 also serves to help secure fixture drain insert assembly 300 ′ in the drain and prevent movement.
[0044] FIG. 10 illustrates a perspective view of the fixture drain insert assembly 300 ′. Material support module 280 is assembled and secured to trap cover 250 . Legs 251 hold trap cover 250 up from drain cover skirt 255 , with gasket 210 secured to housing support 220 .
[0045] FIG. 11 illustrates a cross-sectional view of the fixture drain insert assembly 300 ′ taken along the line XI-XI of FIG. 10 . Material support module 280 contains material 290 , which may be a block, gel or liquid material containing a fragrance, enzyme/bacteria or other cleaning/deodorizing agent. Material support module 280 is secured to trap cover 250 at securing components 258 and 288 . In the embodiment shown, securing component 288 (on material support module 280 ) is a threaded female component into which securing component 258 (on trap cover 250 ), a threaded male component, is threaded. Other securing structures, however, may be used.
[0046] Trap cover 250 with interlocking structures 256 on inner diameter 257 are joined with corresponding interlocking structures 226 on housing support 220 in a bayonet mount style. Elastomer trap 230 with two flaps 232 is secured between trap cover 250 and housing support 220 , and drain cover skirt 255 is secured around inner diameter 257 of trap cover 250 .
[0047] FIG. 12 illustrates a cross-sectional view of the fixture drain insert assembly 300 ′ inserted in a urinal 350 taken alone the line XII-XII of FIG. 7 . Material support module 280 projects into the basin of urinal 350 and is visible. Trap cover is secured underneath material support module 280 outside of the urinal drain with drain cover skirt 255 creating a liquid seal around the drain. Gasket 210 , secured to housing support 220 , creates a gas tight seal from under the urinal drain. Elastomer trap 230 is secured between housing support 220 and trap cover 250 .
[0048] In the exemplary embodiment shown, as liquid (i.e., water, urine, etc.) flows enters the urinal basin, the liquid passes through drain apertures 259 of trap cover 250 , through elastomer trap 230 and out housing support 220 . Elastomer trap 230 acts as a one-way valve permitting only the passage of liquid downward through its flaps 232 and preventing the backup of liquid or gas through elastomer trap 230 . Gasket 210 and drain cover skirt 255 further prevents gases and liquids from escaping back up the urinal drain. Drain cover skirt 255 also directs liquids to drain apertures 250 of trap cover 250 so that the liquids (i.e., urine, water) are directed through elastomer trap 230 .
[0049] While in the exemplary embodiments above fixture drain insert assembly 300 / 300 ′ have been shown in use with wall-mounted urinals, fixture drain insert assemblies 300 / 300 ′ may be used with other fixtures, including, but not limited to, floor mounted urinals, such as depicted in FIGS. 13-14 . FIGS. 13-14 illustrate fixture drain insert assembly 300 ′ with material support module 280 and drain cover skirt 255 secured in a floor mounted urinal 350 .
[0050] FIGS. 15-20 illustrate alternative embodiments of a fixture drain insert assembly. In FIG. 15 , fixture drain insert assembly 300 ″ is as shown in FIGS. 7-14 , but uses a ball valve 230 ″ instead of elastomer trap 230 . In the exemplary embodiment shown, housing support 220 ″ is threaded; however, it is to be understood that housing support 220 may be any shape or include threads or other securing structures to be configured for insertion into a given drain style. In the embodiment illustrated in FIG. 16 fixture drain insert assembly 300 ′″ uses a bulb valve 230 ′″ instead of elastomer trap 230 . As illustrated in FIG. 17 , different styles of valves (i.e., elastomer trap, ball valve, bulb valve) may be used with different styles of existing traps. In the embodiment shown in FIG. 17 , fixture drain insert assembly 300 ″ with bulb valve 230 ′″ uses trap housing 240 , as shown with FIGS. 1-6 , and is shown in a J-trap design. However, it should be understood that the different fixture drain insert assembly embodiments (i.e., trap housing style and trap cover/drain cover skirt style) may be used with a variety of valves and therefore be configured for use in a variety of drain/trap styles.
[0051] FIGS. 18-20 illustrate an exemplary fixture drain insert assembly 300 ′″″ as used with a two-inch code valve ( 298 a , 298 b ). The embodiment in FIGS. 16-17 uses a trap cover 250 with drain cover skirt 255 , while the embodiment in FIG. 18 uses a trap housing 240 with a bulb valve 230 ′″.
[0052] In the exemplary embodiments described above, the embodiments of the fixture drain insert assembly are described for use with various valve, trap and drain styles. It is understood that assemblies described herein may be used with any valve and trap known in the art, including, but not limited to, elastomer valves comprising at least two flexible flaps, ball valves, bulb valves, two-inch code valves, J-traps, and S-traps.
[0053] It is specifically intended that the hygiene product disposal apparatus and method of use not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.
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A fixture drain insert assembly includes a material module support with a securing component; at least one of a trap housing or trap cover comprising an upper surface with a securing component corresponding to the securing component of the material support module, a plurality of drain apertures, and an interlocking structure on the external surface of an inner diameter; a valve; a gasket; and a housing support comprising a body with an open top end having an interlocking structure and an inner lip on the inner surface of the open top end, wherein the interlocking structure corresponds to and mates with the interlocking structure of the trap housing or trap cover. The fixture drain insert assembly can be retrofit into existing fixtures such as urinals to create efficient and clean low water to no-water use fixtures or be integrated into new fixtures with corresponding mating features to optimize fit.
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REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 10/054,258 filed Jan. 22, 2002 now U.S. Pat. No. 6,497,269, which is a continuation of U.S. patent application Ser. No. 09/828,408, filed Apr. 6, 2001 now U.S. Pat. No. 6,360,807, which is a continuation-in-part of U.S. patent application Ser. No. 09/473,606 filed Dec. 29, 1999 now abandoned, the disclosure of which is hereby incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention is directed to processes for forming styrenic copolymers, and their related end uses. In particular, the present invention is directed to processes for preparing patterns for use in metal castings.
BACKGROUND OF THE INVENTION
Styrenic polymers have a wide variety of applications, including the formation of expanded polystyrene which can be used to make a variety of products. Processes for forming styrenic polymers include emulsion polymerization, suspension polymerization, and the use of particular suspensions or emulsion aids.
Polymer particles are useful in applications such as the formation of expanded resins, for example, expanded polystyrene. Expanded polystyrene and other expanded resins can be prepared from expandable polymeric particles made by contacting the polymeric particles with a volatile compound known as a “blowing agent” or “expanding agent”. Such agents include aliphatic hydrocarbons such as butane, pentanes, hexanes, and halogenated hydrocarbons such as trichloromethane, trichlorofluoromethane, and methyl chloride. The particles in contact with the expanding agent may be expanded by heating, or by exposure to reduced pressure as in a vacuum. The size and size distribution of the expanded particles will depend upon the size and size distribution of the expandable beads.
Expanded and expandable polymeric resins have applications in packaging, consumer products, and in materials processing. Examples of materials processing applications for expanded polymeric resins include so-called “lost foam casting”, also called “evaporative pattern casting”. In lost foam casting, molten metal is poured into a pattern made of expanded polymeric material, i.e. a foam, coated with a refractory material surrounded and supported by unbounded sand. The foam is decomposed by the heat of the molten metal and replaced by the metal.
A need remains for new and/or improved processes for forming styrenic polymers, as well as for related improvements in lost foam casting applications.
SUMMARY OF THE INVENTION
The present invention is related to a process for the preparation of a vinyl aromatic polymer, e.g., a polystyrene suitable for lost foam casting applications. Pre-expanded beads (prepuff) prepared from polystyrene containing an effective amount of a combination of a bromine-attached aliphatic or aromatic flame retardant and optionally dicumyl peroxide can be used in conventional steam molding equipment to produce low density patterns. Aluminum castings made from the polystyrene/combination material show significantly less signs of carbon deposits, although any metal may be benefited by the technology of the present invention. The polystyrene smoothly and controllably decomposes to give a smooth, clean metal casting.
The vinyl aromatic polymer particles suitable for use in the process of this invention may be spherical or irregularly shaped particles of any of the thermoplastic vinyl aromatic polymers usable in the preparation of molded foam articles. Although homopolymers or copolymers of any vinyl aromatic monomer may be employed, styrene and substituted styrene monomers are preferred. Examples of suitable vinyl aromatic monomers include, but are not limited to, styrene, α-methyl styrene, aryl-methyl styrene, aryl-ethyl styrene, aryl-isopropyl styrene, aryl-tert-butyl styrene, vinyl toluene, vinyl xylene, aryl-chlorostyrene, aryl-chloromethylstyrene, vinyl napthalene, divinyl benzene, and the like. Minor amounts (i.e., up to about 50 mole percent) of other ethylenically unsaturated copolymerizable monomers may also be used, including, for example, butadiene, acrylic acid, methacrylic acid, maleic anhydride, methyl methacrylate, acrylonitrile, and the like. The vinyl aromatic polymer may be rubber modified with an elastomer such as polybutadiene or styrene/butadiene block or random copolymers. The vinyl aromatic polymer particles should preferably be from about 0.1 to 2 mm in average diameter. Methods of obtaining suitable particles such as suspension polymerization or pelletization are well known in the art.
The polymers useful in the present invention include polystyrene having a molecular weight of 150,000 to 350,000, preferably from about 170,000 to 320,000. Small spherical beads of polymer having bead diameters between 100 and 600 microns, preferably between 150-500 microns, and most preferably between 250-425 microns are useful for purposes of the present invention.
Thus, the present invention is directed to a process for preparing a pattern for use in making metal castings (e.g., aluminum, brass, bronze, ductile, modular or grey iron, magnesium or steel) which have significantly less residual carbon on the surface which comprises:
(a) adding an amount, effective for the purpose, of a combination of a bromine-attached aliphatic or aromatic flame retardant and optionally dicumyl peroxide to a suspension of vinyl aromatic polymer particles having a molecular weight of about 150,000 to 350,000 and having a bead size between 100 and 600 microns in diameter; and
(b) adding a suitable blowing agent to the beads and heating to impregnate the beads.
By bromine-attached aliphatic or aromatic flame retardant, it is meant an organic bromine compound having more than 40% by weight bromine and not more than 80% by weight bromine. From about 0.20 to 1.2 parts by weight of flame retardant per 100 parts by weight of vinyl aromatic polymer particles is needed to be effective. Optionally, from about 0.01 to 0.20 percent of the dicumyl peroxide material is added to the system in need of treatment. However, it can be envisioned that a range of up to 5.0 wt. % flame retardants may be required in certain instances to reduce the carbon defects to an insignificant amount.
Suitable blowing agents are, e.g., butane, n-pentane, isopentane, cyclopentane, hexanes, cyclohexane, carbon dioxide, fluorinated hydrocarbons and mixtures thereof. The combination of the bromine-attached aliphatic or aromatic flame retardants and optionally dicumyl peroxide may be added to the suspension as well as the blowing agent.
A number of brominated fire retardant materials are effective for purposes of the present invention. The HBCD to be used as the fire-retardant agent in the process of this invention can be any of the hexabrominated derivatives of cyclododecatriene. Any of the isomers of hexabromocyclododecane are suitable for use. Mixtures of different isomers of hexabromocyclododecane can also be employed. The average particle size of the hexabromocyclododecane may be less than about 100 microns, and is preferably less than about 25 microns. HBCD is available commercially from Ameribrom, Inc., Albermarle Corp. (“SAYTEX HBCD”), and Great Lakes Chemical Corp. (“CD-75P”).
The fire-retardant expandable vinyl aromatic polymer beads produced by the process of this invention may be readily shaped into molded foam articles by heating in molds which are not gastight when closed. The beads expand to form prepuff which after aging can be steamed and fused together to form the molded article. Such methods of preparing molded-bead foams are well-known and are described, for example, in Ingram et al, “Polystyrene and Related Thermoplastic Foams” Plastic Foams, Marcel Dekker (1973), Part II, Chapter 10, pp.531-581, Ingram “Expandable Polystyrene Processes” Addition and Condensation Polymerization Process American Chemical Society (1969), Chapter 33, pp. 531-535.
Molded foam articles prepared using the fire-retardant expandable vinyl aromatic beads of this invention are resistant to flame, even when relatively low levels of the flame retardant (e.g., hexabromocyclododecane and others) are present. The hexabromocyclododecane is incorporated with the beads rather than coated on the surface of the beads and thus does not interfere with the fusion of the beads when they are expanded into molded foam articles. The density, tensile strength, heat resistance and other physical and mechanical properties of the foams are unaffected by the presence of the hexabromocyclododecane if the process of this invention is employed.
Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The following examples, therefore, are to be considered as merely illustrative and not limitative of the claims or remainder of the disclosure in any way whatsoever.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An object of the present invention is to completely eliminate any folds in lost foam castings. In the testing of the present invention, a box pattern is molded from EPS (expandable polystyrene) prepuff, conditioned, and coated with a ceramic finish. The coated EPS patterns are glued in clusters to a sprue which is then placed in a flask, and sand is compacted around it. The box pattern is gated to allow the converging metal, Aluminum 319 alloy at 1350° F., to fill the patterns. The placement of the gating in the box pattern is done to maximize fold defects from converging metal fronts in the casting.
The EPS bead, created in a two-step process, has a molecular weight of approximately 240,000, a bead size distribution ranging from 250 to 500 microns, and a pentane blowing agent.
The first step in a two-step process is the polymerization of styrene using benzoyl peroxide as an initiator. The suspension process is carried out in water in a stirred reactor using tricalcium phosphate (TCP) as a suspending agent and sodium dodecyl benzenesulfonate as an anionic surfactant to keep the styrene droplets from coalescing when they form discrete particles of polystyrene beads. A secondary initiator such as t-butyl perbenzoate is used to reduce the unreacted styrene to less than 1000 ppm in a secondary cure cycle.
The second step of the two-step process is to suspend the polystyrene beads in water while carrying out an impregnation using pentane as the blowing agent near or above the softening point of the polystyrene. The impregnated beads are commonly known as EPS.
T24 polystyrene beads, the feedstock used to make T170B, a commercially available expandable polystyrene bead which is used for lost foam production, were impregnated with pentane containing various brominated organic additives, discussed below. The EPS manufactured in this way has the same molecular weight and bead size distribution as the starting material.
Five commonly used flame retardants in the modified grade of EPS are shown in Table 1, below. The flame retardants are incorporated usually in levels less than 1.0 wt %. In some cases, a relatively high temperature peroxide, such as dicumyl peroxide, is added during the impregnation cycle along with the flame retardant. Dicumyl peroxide acts as a synergist and allows the use of less flame retardant while giving the same level of protection during a fire. Other organic peroxides can be used if the decomposition half-life is greater than 2 hours at 100° C., for instance, Vulcup R [α, α′-bis (t-butylperoxy) diisopropylbenzene].
TABLE 1
Product
Chemical Name
Synergist
A
Tetrabromocyclooctane
Dicumyl peroxide
B
Dibromoethyl dibromocyclohexane
Dicumyl peroxide
C
Hexabromocyclododecane
Dicumyl peroxide
D
Tetrabromophenol A bis (allyl ether)
None
E
2,4,6-Tribromophenyl allyl ether
None
While one of the purposes of the flame retardant in EPS is to generate HBr while being heated at elevated temperatures, a more important function is to generate free radicals which reduce the polystyrene molecular weight so that the material quickly can liquefy. This can be verified by running melt index experiments using ASTM D-1238, run under condition G using a weight of 4900 g at 200° C. with and without flame retardants. In the presence of active flame retardants or peroxides, the melt flow of the extrudate will come out like water, while the control will flow like molasses.
The general procedure for making a control was as follows: 235 pounds of water and 235 pounds of T24 polystyrene beads were added to a 50 gallon reactor being stirred at 250 RPM; 474 g of TCP, 29 g of sodium dodecyl benzenesulfonate, and 160 g of Triton® X-102 (alkylaryl polyether alcohol), a nonionic surfactant having an HLB value of 15, were then added. Suitable nonionic surfactants have an HLB value ranging from 12 to 18.
The reactor was heated from room temperature to 225° F. at a rate of 8° F. every 5 minutes. The reactor was purged three times with nitrogen and the pentane was added starting at 125° F. at a rate of 1.5 lb every five minutes. A total of 20 pounds was used. When the temperature reached 225° F., it was kept at this temperature for three hours. The reactor was then cooled to 110° F. and the contents were emptied into a batch out tank containing water and hydrochloric acid (HCl). The contents were acidified to a pH of around 2.0 to remove TCP. The beads were dried by passing them through a dryer and screened to remove any agglomerated beads. Each hundred pounds of dry beads were then treated with 10 grams of silicone oil.
The same procedure was followed when adding brominated organic additives during the impregnation of the polystyrene beads. Thus, for run 3,320 g of dicumyl peroxide was added. For run 4,725 g of HBCD was added.
EPS box patterns were prepared from the EPS beads made in runs 1 to 9. The EPS parts were conditioned and then dipped into a ceramic coating. After drying, the parts were glued in clusters to a sprue and then placed in a flask. Sand was compacted around them. Aluminum 319 alloy was poured into the patterns at 1350° F., and afterward the parts were examined for folds.
Control runs 1 and 2 were poured at different times and resulted in average fold defect values of 26 and 34 mm 2 . Twenty castings were poured for control run 1, while ten castings were poured for control run 2, each casting containing two box patterns. EPS does not depolymerize cleanly back to 100% monomeric styrene, as does methyl methacrylate from polymethyl methacrylate. The amount varies from 70 to 75% depending on the actual conditions used during the depolymerization (around 400° C.). Thus, each time decomposition of the polystyrene occurs, the results will be different in terms of the amount of gases, styrene, and other liquid and solid residues being generated. At higher temperatures used for pouring aluminum, the amount of styrene decreases and the formation of carbon, methane, and hydrogen are prevalent.
Run 3, using 0.30 wt. % dicumyl peroxide as the additive, resulted in a high concentration of folds, 52 mm 2 , nearly twice as many per area as the control. To retard fold formation, the ceramic coating must provide a physical barrier between the metal front and the sand. The coating allows for the removal of gas decomposition products at a controlled rate to escape into the sand. In addition, the coating assists in the removal of styrene and other liquid decomposition products by wicking the liquids into the sand. If there is solid residue from the decomposition of polystyrene, it will be trapped as the metal flows and displaces the polystyrene. If the additive is ineffective, as it is for this run, the additive helps to form “globs” of polystyrene residue which accumulate and lead to folds as the metal front converges.
Runs 4 and 5 used 0.68 wt. % HBCD from two different manufacturers. Although HBCD exists in three isomeric forms, the isomer content is not important in reducing fold defects, as the fold areas were identical (4 mm 2 ). The above additive (HBCD) allows for a complete breakdown of the polystyrene into liquid and gaseous products faster and more consistently than some other additives.
Run 6 shows that using 0.30 wt. % dicumyl peroxide with 0.68 wt. % HBCD resulted in nearly as many folds per area as the control. Run 7 using 0.10 wt. % dicumyl peroxide with 0.68 wt. % HBCD resulted in the disappearance of nearly all folds.
Run 8, which had a reduced HBCD level from 0.68 to 0.40 wt. %, showed an increase in the fold area from 4 to 9 mm 2 , but was still much less than the control.
Run 9 showed that adding product D to HBCD increased the fold area. Thus in this application, product D is not beneficial.
TABLE 2
Aluminum Casting Results-Runs 1 to 9
(Control and Various Additives)
Average
% Flame
Fold Area
Retardant
Run #
Flame Retardant
Synergist
mm 2
Incorp.
1
None
None
26
2
None
None
34
3
None
dicumyl peroxide
52
(0.3 wt. %)
4
HBCD
None
4
(0.68 wt. %)
5
HBCD
None
4
(0.68 wt. %)
6
HBCD
dicumyl peroxide
23
(0.68 wt. %)
(0.3 wt. %)
7
HBCD
dicumyl peroxide
1
95.6
(0.68 wt. %)
(0.1 wt. %)
8
HBCD
None
9
95.1
(0.40 wt. %)
9
HBCD
Product D
10
(0.50 wt. %)
(0.2 wt. %)
TABLE 3
Aluminum Casting Results-Runs 10 to 13 (EPS Flame Retardants)
Flame Retardant
Average
% Flame Retardant
Run %
(0.68 wt. %)
Fold Area mm 2
Incorp.
10
Product D
11
95.3
11
Product A
0
76.9
12
Product B
6
55.0
13
Product E
7
81.3
Runs 10 to 13 were better than the control in reducing the fold area. Run 11 had no folds in any of the 10 castings, and gave the best results of any of the flame retardants tested. Tetrabromocyclooctane is very effective in quickly reducing the molecular weight of polystyrene at elevated temperatures in a consistent manner. The by-products, liquids and gases, pass through the coating efficiently during the metal pour resulting in converging metal fronts having no carbon defects.
TABLE 4
Aluminum Casting Results-Runs 14 to 15 (Other Flame Retardants)
Flame
% Flame
Retardant
Average Fold
Retardant
Run #
(0.68 wt %)
Area mm 2
Chemical Name
Incorp.
14
Product F
28
Decabromodiphenyl
75.0
oxide
15
Product G
55
Octabromodiphenyl
89.8
oxide
Run 14 produced a similar folding area compared to that of the control. Run 15 nearly twice as many folds as the control.
In order to further demonstrate the effectiveness of the present invention, the seven flame retardants shown in the table below were subjected to TGA (thermal gravimetric analysis) under N2 at 10° C. per minute. The shape of the curve was instructive; products A, B, C and E, all decompose sharply by 305° C. Products F and G decompose above 390° C. Product D decomposes incompletely from 200 to 500° with 80% loss at 264° C.
TABLE 5
Average Fold Area
Product
° C.
% Wt. Loss
mm 2
A
294
100
0
B
277
100
6
C
303
100
4
D
264
80
11
E
244
96
7
F
396
100
56
G
422
100
28
EPS beads containing Products A, B, C and E produced casting with the smallest areas of fold defects. Product D gave the least effective results, but was still more effective than the control.
TGA decomposition is a good indicator of whether the flame retardant will decrease fold defects. This could be due to the fact that product D does not decompose quickly over a short temperature range. By not decomposing, it added to the residue being generated during the process and increases the fold area. Globs of material which do not decompose cleanly would be expected to accumulate as the metal front rises to the surface, and remain there after a pour as a carbon defect.
Products F and G, which decompose above 390° C., gave more folds than the other flame retardants. While product G is similar to the control in fold area, use of product F resulted in nearly twice as many folds as the controls.
The above results indicate that these flame retardants are too stable, i.e., by not decomposing at a much lower temperature, they add to the residue being generated during the process. Note that these two flame retardants are not used as flame retardants for EPS, but are used successfully in high impact polystyrene to reduce flammability. It is apparent that only those flame retardants which are commonly used as flame retardants for EPS, other than product D, will significantly reduce fold formation in patterns used in the lost foam process.
While this invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of this invention will be obvious to those skilled in the art. The appended claims in this invention generally should be construed to cover all such obvious forms and modifications which are within the true spirit and scope of the present invention.
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The present invention is directed to processes for forming styrenic polymers, and their related end uses. In particular, the present invention is directed to processes for preparing patterns for use in metal castings.
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RELATED APPLICATION
[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application Nos. 61/151,347 and 61/151,351, filed on Feb. 10, 2009, the entire disclosures of which are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] This invention relates to illumination systems, and in particular to systems involving adjacent lighting panels.
BACKGROUND
[0003] Slim illumination systems are desirable for many illumination applications, and particularly for low-profile back-illuminated displays. A slim illumination system can be assembled by arranging many small lighting elements in an array. Each lighting element may be, for example, a light-guide panel having a light source that injects light into an “in-coupling” region of the panel and an illumination region where light is “out-coupled” from the light-guide element to provide illumination. In general, the light is emitted substantially uniformly across the illumination region.
[0004] In a typical array configuration, light-guide elements are arranged adjacently in longitudinal and lateral directions. Even if the light-guide elements are butted tightly together, gaps will remain between adjacent elements. Indeed, gaps are often provided intentionally to allow the light-guide elements to expand and contract as the ambient temperature varies without damaging the overall array configuration. Unfortunately, the intensity of light at or near a gap will typically differ from that emitted from the illumination regions. Therefore, the gaps may appear as “stitches”—i.e., relatively dark or light linear discontinuities—in the array. These artifacts are visible in both the longitudinal and lateral directions.
SUMMARY OF THE INVENTION
[0005] Illumination devices according to the present invention eliminate or at least reduce the “stitch” effect. As a result, light of substantially uniform intensity is emitted across the entire slim illumination system. This can be achieved by reflecting, through the gaps between adjacent light-guide elements, light directed through the bottom surfaces of the elements. One or more mirrors may be disposed below the light-guide elements, and by adjusting the distance between the bottom surfaces and the mirror(s), the intensity of light reflected through the gap can blend unnoticeably with the light emitted from the illumination surfaces of the light-guide elements. The mirror-to-surface spacing may be adjustable to compensate, for example, for temperature changes, which can cause the light-guide elements to expand or contract and thereby change the gap width.
[0006] In a first aspect, embodiments of the invention relate to an illumination device that comprises a first light-guide element and a second light-guide element. Each light-guide element may include an illumination surface from which light is emitted, and a bottom surface opposite the illumination surface. The first and second light-guide elements are positioned such that there is a gap between the two light-guide elements, i.e., the light-guide elements may not be in contact with each other. One or more mirrors are positioned below the bottom surfaces of the light-guide elements and below the gap between them. The light-guide elements have externally reflective side walls (perpendicular to the illumination and bottom surfaces) that reflect light back into the gap.
[0007] In some embodiments of the illumination device, one or more mirrors are spaced apart from the bottom surfaces of the light-guide elements. One or more mirrors can be specular and one or more mirrors can be diffusive. The illumination device may also include two mirrors positioned such that a portion of one mirror overlaps a portion of the second mirror under the gap.
[0008] In another aspect, the invention relates to a planar illumination device comprising first and second light-guide elements each comprising an illumination surface and an opposed bottom surface, where the first and second light-guide elements are separated by a gap; at least one mirror in opposition to the bottom surfaces of the light-guide elements and underlying the gap; and a position changer for changing a position of the at least one mirror relative to the bottom surfaces of the light guide elements. This facilitates responsiveness to changes in the width of the gap. A position changer may, for example, respond to a change in temperature, e.g., by moving a mirror closer to the bottom surfaces when the temperature increases, and moving a mirror away from the bottom surfaces when the temperature decreases. The position changer can include an expandable element positioned below the mirror. The expandable element may expand when the temperature increases, thereby pushing the mirror towards the bottom surfaces of light-guide elements, and contract when temperature decreases, pulling the away from the bottom surfaces. Alternatively, the position changer may include one or more expandable elements and one or more fulcrums, positioned above the mirror.
[0009] In some embodiments, the first and second light-guide elements may each have a mirrored (i.e., externally reflecting) side wall facing the gap. The reflective side wall can be formed using a partially reflecting mirror, and the reflectivity of the partially reflecting mirror may vary along the length of the side wall.
[0010] One or more mirrors in the illumination device can be positioned at an angle with respect to the bottom surfaces, and the angle may be along a light-guiding direction i.e. an end of the mirror near the in-coupling region may be close to the bottom surfaces and the opposite end of the mirror, near the end wall of the light-guide element opposite to the in-coupling region, may be relatively at a greater distance from the bottom surfaces. Alternatively, the end of the mirror near the in-coupling region may be far from the bottom surfaces and the opposite end near the end wall may be at a relatively shorter distance from the bottom surfaces.
[0011] In some embodiments, the illumination device may include two or more mirrors positioned below the bottom surfaces of light-guide elements. One or more of these mirrors can be positioned substantially in parallel to the bottom surfaces, and one or more of these mirrors may be positioned at an angle with respect to the bottom surfaces. Alternatively, one or more of these mirrors may be positioned substantially in parallel to the bottom surface of the first light-guide element, and one or more mirrors can be positioned at an angle with respect to that bottom surface. The latter configuration can be employed when the bottom surfaces of the two light-guide elements may themselves be at an angle with respect to one another.
[0012] The bottom surfaces of the light-guide elements can have out-coupling features, which can influence the distribution of light from the bottom surface. For example, an out-coupling feature can vary the number of rays transmitted through the bottom surface and may also vary the angle at which such rays are transmitted. The out-coupling features can be bumps and/or grooves.
[0013] In a second aspect, embodiments of the invention relate to an illumination device that comprises a first light-guide element and a second light-guide element. Each light-guide element may include an illumination surface from which light is typically emitted, and a bottom surface opposite to the illumination surface. The first and second light-guide elements are positioned such that there is a gap between the two light-guide elements, i.e., the light-guide elements may not be in contact with each other. The first and second light-guide elements may each have a mirrored side wall facing the gap. The mirrored side wall can be formed using a partially reflecting mirror, and the reflectivity of the partially reflecting mirror may vary along the length of the side wall.
LIST OF FIGURES
[0014] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the present invention are described with reference to the following drawings, in which:
[0015] FIG. 1 is a plan view of light-guide elements arranged in an array to form an illumination area.
[0016] FIGS. 2A and 2B are plan and elevational views, respectively, of a single illumination element.
[0017] FIG. 3A is a sectional elevation of a portion of a light-guide element having convex bumps as bottom-surface out-coupling features.
[0018] FIG. 3B is a sectional elevation of a portion of a light-guide element having concave features as bottom-surface out-coupling features.
[0019] FIG. 4A is a sectional elevation schematically illustrating the behavior of light in connection with the embodiments shown in FIGS. 3A and 3B , using a single underlying mirror.
[0020] FIG. 4B is a sectional elevation schematically illustrating the behavior of light in connection with the embodiments shown in FIGS. 3A and 3B , using a pair of underlying mirrors that overlap beneath the gap between light-guide elements.
[0021] FIGS. 5A and 5B are partial sectional elevations schematically illustrating two temperature-responsive embodiments of the present invention.
[0022] FIG. 6 is a partial sectional elevation schematically illustrating an embodiment involving a tilted or angled mirror.
[0023] FIGS. 7A and 7B are plan and partial sectional elevations, respectively, of an embodiment involving blurring of stitch artifacts.
DETAILED DESCRIPTION
[0024] With reference to FIG. 1 , an illumination surface 100 is formed by arranging a plurality of light-guide elements 110 in an array. In the surface 100 , a plurality of gaps 115 occur between adjacent light guide elements 110 . With changes in temperature, light-guide elements 110 can contract or expand, thereby changing the widths of the gaps 115 (which may be intentionally created to accommodate temperature-induced changes in the sizes of the light-guide elements 110 ). The dimensional response of the light-guide elements 110 to temperature depends on the material of the light-guide element, as well as the mechanical harness used to create the array 100 . For polymer-based light-guide elements, the change along one dimension can be 0.1 mm per 25° C.
[0025] As shown in FIGS. 2A and 2B , an individual light-guide element 210 includes an in-coupling region 212 , which receives light from a source such as a light-emitting diode (LED) (not shown); an illumination region 214 ; and opposite the illumination surface 214 , a bottom surface 216 . The light-guide element 210 also has side walls 218 and an end wall 220 distal to the in-coupling region 212 . Light is generally emitted from the illumination surface 214 . End wall 220 has a reflective coating so that light does not penetrate it; instead, it is retained within the light-guide element 210 .
[0026] An embodiment of the present invention is shown in FIG. 3A . A light-guide element 310 has an illumination surface 314 and an opposed bottom surface 316 (as well as the other features, not illustrated here, that are shown in FIGS. 2A and 2B ). A mirror 325 is positioned below the bottom surface 316 . The bottom surface 316 has a series of bumps 317 as out-coupling features; that is, these features direct light traveling within the body of light-guide 310 out the bottom surface 316 . Without the out-coupling bumps 317 , light would not be emitted through bottom surface 316 .
[0027] A ray of light 330 in the light-guide element 310 incident on a bump 317 may be reflected as ray 332 toward the illumination surface 314 , in which case it may be emitted as ray 334 from the illumination surface 314 . Alternatively, a ray 330 incident on bump 317 may be directed through the bottom surface as ray 336 . Upon exiting the bottom surface 316 , ray 336 may be reflected back into light-guide element 310 (i.e., through bottom surface 316 ) by mirror 325 .
[0028] The light reflected by mirror 325 may be emitted subsequently from a gap between adjacent light-guide elements. In order for the intensity of light emitted from a gap to approximate the intensity of light emitted from the illumination surface 314 , a certain amount of light (i.e., the number of light rays 336 ) must be directed through the bottom surface 316 toward mirror 325 . In the light-guide element 310 , bumps 317 on the bottom surface 316 may direct approximately 90% of light incident upon them through bottom surface 316 .
[0029] An alternative structure is shown in FIG. 3B . In this embodiment, the bottom surface 316 has dents 319 as bottom-surface out-coupling features. Dents 319 may direct approximately 50% of light incident upon them through bottom surface 316 .
[0030] FIG. 4A illustrates the manner in which the embodiments shown in FIGS. 3A and 3B direct light through a gap between light-guide elements to hide stitch artifacts. Two light-guide elements 402 , 404 are positioned adjacent each other. The light-guide element 402 has an illumination surfaces 410 and an opposed bottom surface 412 . Similarly, light-guide element 404 has an illumination surface 414 and an opposed bottom surface 416 . FIG. 4A schematically shows out-coupling features 418 generically (i.e., they can be bumps, grooves or both) on bottom surfaces 412 and 416 . The light-guide elements 402 , 404 are separated by a gap 420 . A mirror 425 is positioned below the bottom surfaces 412 , 416 and gap 420 .
[0031] A ray of light reflected by mirror 425 through light-guide element 402 may be emitted as ray (b). On the other hand, a light ray reflected by mirror 425 through light-guide element 402 may be retained within the element 402 by total internal reflection, i.e., as ray (c). At least some of the rays striking mirror 425 due to out-coupling features 418 will be reflected into the gap 420 and emerge therefrom, as exemplified as ray (a). Because most of the light reflected into gap 420 will emerge as visible light, whereas only a portion of the light reflected into the light-guide elements 402 , 404 is actually emitted through respective surfaces 410 , 414 (the remainder being confined with one of the elements), the “extra” light through gap 420 can serve to hide or at least reduce the stitch artifact.
[0032] Thus, to achieve substantially uniform intensity of light across illumination surfaces 410 , 414 and gap 420 , the quantity of reflected light retained within elements 402 , 404 (ray (c)) versus the quantity of reflected light emitted from elements 402 , 404 (ray (b)), as well as the amount of light entering gap 420 , may be adjusted by varying the distance d between mirror 425 and the bottom element surfaces 416 , 418 . If mirror 425 were placed in contact with bottom surfaces 412 and 416 , relatively little light would be reflected by mirror 425 into gap 420 , causing the gap to appear dark relative to illumination surfaces 410 and 414 . If mirror 425 were situated too far from bottom surfaces 412 , 416 , too much light would be reflected by mirror 425 into gap 420 , causing gap 420 to appear brighter than illumination surfaces 410 , 414 . By optimizing d, the light through gap 420 substantially matches the light emitted through illumination surfaces 410 , 414 .
[0033] As shown in FIG. 4B , two mirrors 427 , 429 may be positioned below the bottom surfaces 412 , 416 , respectively, and overlap beneath gap 420 . Specifically, a portion 443 of mirror 429 is positioned below a portion 441 of mirror 427 . As mirrors 427 and 429 can be thin, the distance of mirror 427 from the bottom surface 412 can be substantially the same as the distance of mirror 429 from the bottom surface 416 . Accordingly, the intensity of light emitted from gap 420 may be substantially the same as the intensity of light emitted from the illumination surfaces 410 and 414 , eliminating or at least reducing the stitch artifact at gap 420 .
[0034] One limitation of these configurations is that they do not compensate for temperature-induced changes in the width of the gap. If the gap width changes, the amount of light emitted from the gap will also change unless the amount of light reflected into the gap is altered. While this may not be noticeable in some applications, it may well be in others. Two embodiments adapted to alter the amount of light reflected through the gap in a temperature-responsive manner are shown in FIGS. 5A and 5B , respectively.
[0035] In an embodiment shown in FIG. 5A , the light-guide elements 502 , 504 have a gap 520 between them. A mirror 525 (e.g., a polished aluminum plate) is positioned below the bottom surfaces 512 , 516 of light-guide elements 502 , 504 and gap 520 . An expansion element 540 , which expands when temperature increases and contracts when temperature decreases, is positioned below and in contact with the underside of mirror 525 . When the temperature increases, causing light-guide elements 502 , 504 to expand, gap 520 narrows. But at the same time, expansion element 540 expands, pushing mirror 525 toward the bottom surfaces 512 , 516 (the degree of mirror displacement depending on the temperature change). As explained above, as the distance between mirror 525 and bottom surfaces 512 , 516 decreases, the amount of reflected light transmitted through gap 520 also decreases. But because gap 520 has become narrower, decreasing the “extra” light emitted through the gap has the effect of preventing overcorrection (and retaining a substantially similar light output across the entire illumination surface).
[0036] Conversely, when the temperature decreases, causing light-guide elements 502 , 504 to contract, gap 520 widens. Contraction of expansion element 540 pulls mirror 525 away from the bottom surfaces 512 , 516 , increasing the amount of reflected light through the now-wider gap 520 to prevent undercorrection. Thus, both in the case of increased and decreased temperature, the amount of light emitted from gap 520 remains substantially the same as that obtained without the change in temperature.
[0037] Another approach to temperature correction is shown in FIG. 5B . A pair of expansion elements 542 , 544 and a pair of fulcrums 546 , 548 are positioned above mirror 525 . As the temperature increases, expansion elements 542 , 544 expand, pushing portions 527 , 528 of mirror 525 away from the bottom surfaces 512 , 516 , respectively. As a result, a portion 529 of mirror 525 is pushed toward the bottom surfaces 512 , 516 , thereby decreasing the amount of light transmitted to gap 520 . Conversely, when the temperature decreases, expansion elements 542 , 544 contract, pulling portions 527 , 528 of mirror 525 toward the bottom surfaces 512 , 516 , respectively, while pushing portion 529 of mirror 525 away from the bottom surfaces 512 , 516 . The effect of these movements is to increase the amount light reflected through gap 520 . It should be noted that only portions of light-guide elements 502 , 504 are shown in the figure; in general, mirror 525 will not extend beyond the boundaries of the light-guide elements.
[0038] In some embodiments, the visibility of a stitch is reduced or eliminated by blurring the light emitted through the gap. With reference to FIG. 6 , a mirror 610 is positioned below the bottom surface 604 of a light-guide element 600 at an angle relative to the bottom surface 604 . Importantly, if the mirror passes beneath the gap, the angle underlies the width of the gap (i.e., the illustrated dimension) but there is no angle along the length of the gap (i.e., the dimension into the page); that is, the distance between the mirror and the plane defined by the bottom surfaces of the light-guide elements varies across, but not along, the gap. The angled position of mirror 610 can be achieved using fasteners or a transparent wedge (both not shown). Moreover, the illustrated embodiment involving one long wedge per light-guide element can be replaced by a “multi-wedge” structure in which multiple wedges, arranged along the width of the light-guide element, so that the light-to-dark variation occurs more than once along the light-guide element.
[0039] As described above, the amount of light transmitted to a gap (not shown) between adjacent light-guide elements increases or decreases as the distance between mirror 610 and the bottom surface 604 increases or decreases, respectively. Consequently, the amount of light reflected back into the light-guide element 600 , and subsequently emitted from the illumination surface 602 of the light-guide element 600 , changes in inverse relation to the distance between mirror 610 and the bottom surface 604 .
[0040] Because mirror 610 is positioned at an angle relative to the bottom surface 604 , its distance from the bottom surface 604 varies along the length of the bottom surface 604 . This causes the amount of light reflected by mirror 610 into the light-guide element 600 , and subsequently emitted through illumination surface 602 , to vary along the length of the illumination surface 602 . As a result, the “extra” light from mirror 610 emitted through the illumination surface 602 is not uniform, but varies gradually from relatively low in region 611 (where the distance between mirror 610 and bottom surface 604 is relatively small) to relatively high in region 613 (where the distance between mirror 610 and bottom surface 604 is relatively large). It should be noted that the in-coupling region of light-guide element 600 is at or beyond (i.e., to the right of) region 611 .
[0041] As the ambient temperature changes, the gap width may change, as explained above. Because the position of mirror 610 is not altered in response to a temperature change in this embodiment, the intensity of light emitted from the gap may also change. But because the intensity of light emitted near the gap varies gradually, the stitch artifact may be less visible.
[0042] Another embodiment in which the visibility of stitch artifacts can be reduced by blurring is shown in FIGS. 7A and 7B . In this embodiment, the light-guide elements 701 , 703 are separated by a gap 720 , and have in-coupling regions 704 , 706 , respectively. A source of light (not shown) injects light into each in-coupling region. A side wall 731 of light-guide element 701 , facing gap 720 , is coated with a partially reflective mirror 741 , and the opposed side wall 733 of light-guide element 703 , facing gap 720 , is also coated with a partially reflective mirror 743 . A partially reflective coating can be formed, for example, by using a mirror coating having varying reflectivity, by introducing openings in the mirror, by varying the sizes of the openings, or by a combination of these techniques.
[0043] As illustrated in FIG. 7B , a light ray 742 transmitted through side wall 731 is reflected by the partially reflective mirror 743 and emitted from gap 720 as ray 744 . By appropriately selecting the reflectivity of partially reflective mirrors 741 , 743 , the number of rays 742 transmitted to gap 720 and the number of rays 744 emitted from gap 720 can be adjusted. Accordingly, light emitted from gap 720 can be made substantially similar in intensity to light emitted from illumination surfaces 705 , 707 of light-guide elements 701 , 703 . Thus, a stitch artifact near gap 720 can be reduced or eliminated. In this embodiment, the reflected light emerging through number of rays 742 transmitted to gap 720 does not change as gap width changes due to a change in temperature. Therefore, a stitch artifact may appear as a line along the length of gap 720 as temperature changes.
[0044] The artifact can be mitigated, however, by blurring the stitch line. To achieve this, the reflectivity of the partially reflective mirrors 741 , 743 is varied along the length of gap 720 . As shown in FIG. 7A , portions 751 , 752 of mirrors 741 , 743 , respectively, have high reflectivity. Accordingly, the intensity of light emitted from gap 720 near the in-coupling regions 704 , 706 is high, causing the gap 720 near the in-coupling regions 704 , 706 to appear relatively bright. Conversely, portions 754 , 755 of mirrors 741 , 743 , respectively, have low reflectivity. Accordingly, the intensity of light emitted from gap 720 near the end of the light-guide elements 701 , 703 opposite the respective in-coupling regions 704 , 706 is low, causing the gap 720 near these ends to appear relatively dark. Because the intensity of light emitted along the length of gap 720 is non-uniform, a stitch artifact does not appear as a line; instead it is blurred, thereby reducing its visibility.
[0045] Although the present invention has been described with reference to specific details, it is not intended that such details should be regarded as limitations upon the scope of the invention, except as and to the extent that they are included in the accompanying claims.
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Illumination surfaces according to the present invention eliminate or at least reduce linear “stitch” artifacts at edges between tiled illumination devices. As a result, light of substantially uniform intensity is emitted across the entire illumination system. This is achieved, in various embodiments, by reflecting, through the gaps between adjacent light-guide elements, light directed through the bottom surfaces of the elements.
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BACKGROUND OF THE INVENTION
[0001] Field of the Invention
[0002] The invention relates to the maintenance of network parameter settings in a device or terminal which accesses services provided by or through a network.
[0003] Description of the Related Art
[0004] In mobile communications systems, a terminal such as a mobile telephone handset is provided with parameter settings which configure the terminal for use in certain operations. For example, a terminal may include settings such as network specific information for different network services. The different network services may include, for example, GPRS access information, SMS (Short Messaging Service) access information, (Multimedia Messaging Service) MMS-settings, WAP settings, user profile information etc. Typically the terminal is configured with network specific information to enable use of such services. If this network specific information is changed, by the user or due to a terminal error, then the services associated with the information may become inaccessible.
[0005] If the terminal is rendered such that the service can no longer be accessed, a user may contact their services provider to obtain any necessary technical support. The technical support then may attempt to correct the problem over the phone by accessing and downloading the correct parameter settings to and from the terminal, or may instruct the user how to reconfigure the network settings of the terminal, or may require that the terminal be brought in for service.
[0006] This procedure for reconfiguring the network settings is disadvantageous. The cost to the operator is significant because of the need to provide trained and experienced staff to provide the technical support. The need to contact the service operator is inconvenient for a user of a device.
[0007] As stated hereinabove, the terminal is configured with network specific information to enable use of such services. In the event that a terminal is roaming, the terminal may become connected in a network to which the specific information for which the terminal is configured may not be useable. The fact that different network providers have different network specific information is one reason why handset manufacturers sell provider-specific variants of phones. As such the phone handset is pre-configured with the desired settings for the network. As a result, when the terminal is used for national or international roaming, certain services may become unavailable due to non-compatibility of a current operator with the phone settings. The user of the terminal may be unable to send MMS or reach their Mailbox or WAP service. The only way around this is to manually reconfigure the terminal settings. However this requires expertise on behalf of the user, and inconvenience.
SUMMARY OF THE INVENTION
[0008] The invention addresses one or more of the above-stated problems, and provides an improved technique for ensuring the correct settings of network parameters in a terminal.
Summary of the Invention
[0009] Statements Equivalent to New Claims to be added when Finalised.
[0010] In a first embodiment there is provided a method of maintaining the settings of a user equipment, comprising: monitoring at least one stored setting in the terminal; responsive to a change in said at least one stored setting notifying a controller; and responsive to said notification selectively resetting said at least one stored setting.
[0011] The selective resetting may be in dependence on whether the change in said at least one stored setting is in error. The monitoring of the user equipment preferably takes place in the user equipment.
[0012] The notification to the controller preferably comprises a transmission to an operator domain for a service associated with the at least one setting. Thus if the setting is associated with an SMS setting, for example, the transmission is to an operator domain associated with such SMS service.
[0013] The notification to the controller may comprise a presence update. As such, the monitoring may be performed by a presence client within the user equipment. The presence update may simply provide an indication of a change in a certain setting, or may identify such change.
[0014] The notification selectively resetting the at least one stored setting may comprise transmitting the at least one stored setting to the user equipment. Such transmission may be made by any means of communication supported by the user equipment, such as over-the-air provisioning, SyncML, or smart messaging. In an embodiment utilising presence services, the transmission may originate from a presence server. In an alternative, the transmission may originate from a device management server.
[0015] The at least one stored setting may comprise one or more of a GPRS access point, an operator portal IP address, or SMS access information, or other variable terminal setting.
[0016] The method is preferably implemented in a mobile communication system, the user equipment being a mobile terminal which accesses services provided by or through a network, such as presence services.
[0017] Embodiments further provide user equipment having at least one setting associated with services, including: a storage means for storing said at least one setting; and a monitoring means for monitoring said at least one setting, and adapted, responsive to a change in said at least one setting, to transmit a notification of such change.
[0018] The services are preferably network services, preferably mobile network services. The settings are preferably variable settings. The settings are preferably user accessible variable settings.
[0019] The user equipment is preferably further adapted to receive a notification to set the at least one setting. Such notification preferably sets the at least one setting to its original setting before the detected change.
[0020] The monitoring means is preferably part of a presence client of the user equipment. The notification of the change is preferably a presence update.
[0021] Embodiments still further provide a communication system comprising a network for providing at least one service to at least one user equipment, the network being adapted to receive a notification from a user equipment of a change in a setting of such user equipment, and responsive thereto transmit a replacement setting to said user equipment.
[0022] The replacement setting preferably corresponds to the original setting in the user equipment.
[0023] The network preferably includes a presence server, said notification comprising a presence update. The presence server is preferably provided in an operator domain of the network.
[0024] The replacement setting may be transmitted by a device management server associated with said network.
[0025] The communication system is preferably a third generation mobile communication system, which system preferably supports presence services.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] For a better understanding of the present invention, reference will now be made by way of example to the accompanying drawings in which:
[0027] FIG. 1 illustrates an example implementation adapted in accordance with one embodiment of the present invention;
[0028] FIG. 2 illustrates the preferred method steps performed in the embodiment of FIG. 1 ;
[0029] FIG. 3 illustrates an example implementation in accordance with another embodiment of the present invention; and
[0030] FIG. 4 illustrates the preferred method steps performed in the embodiment of FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] The present invention is described herein with reference to a particular example, and particularly with reference to a mobile telecommunications system. It will be appreciated by one skilled in the art that the invention is not limited in its applicability to the described embodiments.
[0032] In one embodiment of the present invention, the maintenance of network parameter settings in a terminal is provided for using a presence service architecture. Whilst the presence service architecture provides an especially advantageous basis for the implementation of the present invention, the invention is not limited to a presence services architecture environment.
[0033] The provision of presence services in mobile telecommunications systems is expected to be an important characteristic of third generation (3G) mobile communication systems. Presence services, and presence service architectures, are currently subject to standardisation procedures, and there is not yet a clearly accepted field of terminology. It should therefore be understood that for the purpose of the following description the functionality described is more important than the terminology used, and the invention should not be considered to be limited by any particular terminology used.
[0034] In general, presence is a dynamic (variable) profile of a user, visible to others and used to represent the user, share information, and control services. Presence information may contain, but is not limited to: person (i.e. user) and terminal availability; communication preferences; terminal capabilities; current activity; and location. Presence, therefore, relates to both user and terminal status.
[0035] The invention proposes, in an embodiment, the use of the terminal status aspect of presence services to maintain the terminal settings necessary for accessing network services.
[0036] Referring to FIG. 1 , there is illustrated, generally: a terminal 100 including a memory 104 for storing terminal parameter settings, and a presence client 102 ; a presence server 126 in an operator domain 124 ; a presence server applications interface API 130 ; and a device management server 134 .
[0037] As is known in the art, the terminal 100 stores different network specific settings as the terminal parameter settings in memory 104 . These settings may include, for example, GPRS access point information in storage location 106 , an operator portal IP (Internet protocol) address in storage location 108 , and SMS (short messaging services) access information in storage location 110 . Other or different network specific settings may be stored, e.g. MMS-settings, WAP settings, or user profile information. The network specific information is required to be correctly stored in order to access the associated network service. For example, the SMS access information may define the SMS messaging service centre number, without which the SMS service cannot be supported.
[0038] As currently occurs in the art, the user of a terminal may, by mistake, change one of the parameter settings, such as an IP address for a service, in the memory 104 . Usage of that service may therefore be rendered impossible.
[0039] In accordance with the preferred embodiment of the present invention, the presence client 102 operating in the terminal 100 is adapted to monitor at least some of the parameter settings in the memory 104 , or monitor at least some of the key terminal settings associated with various services. A terminal setting may be a parameter stored within the terminal that is given a certain value, and as such the terms ‘parameter setting’ and ‘terminal setting’ are interchangeable in the present description.
[0040] As such, the presence client 102 is provided with a monitor block 118 , which receives on signal lines 112 , 114 , 116 key terminal settings from the memory locations 106 , 108 , 110 . Thus the monitor block provides the means for monitoring the key terminal settings associated with the provision of certain network services. For example, the SMS access information in storage location 110 may include various further detail associated with the SMS service, but only the SMS call centre number may be provided on line 116 .
[0041] With further reference to FIG. 2 , the presence client 102 is adapted such that the monitor block monitors the parameter settings in a step 200 , and identifies any changes in any such settings. Responsive to detection of a change in step 202 , in a step 204 the presence client 102 is further adapted to notify the presence server associated therewith.
[0042] As illustrated in FIG. 1 , the presence client 102 is adapted such that the monitor block 118 sends a presence update 120 to the presence server 126 in the operator domain 124 . The presence update is sent using any mechanism that still has correct network settings. Thus if the presence update is to notify that the SMS setting parameters have been modified, such presence update may be sent to the presence server via a GPRS communication.
[0043] The communication of a presence update from the presence client to the presence server is well-known to one skilled in the art, and as such a detailed explanation of the presence update mechanism is not given herein.
[0044] The presence update therefore notifies the network operator that a terminal has an incorrect network parameter setting, and that the appropriate correct setting should be resent.
[0045] Various implementations may be provided. The communication from the user equipment may simply indicate that a particular setting has changed. It may indicate the value it has changed to. It may indicate that the setting has an error in it.
[0046] In some circumstances, the change in the setting may be intentionally made by the user. It may therefore be necessary to provide the setting value to the presence server in order to check the setting value.
[0047] Responsive to the presence update, the presence server 126 sends a request for the network parameter setting to be resent to the device management server 134 in a step 206 . The presence server 126 is interconnected to the device management server 134 via the presence server applications interface API 130 which is a web service interface, as is known in the art. Thus the request from the presence server on line 128 goes to the presence server applications interface API 130 , which in turn sends a request on line 132 to the device management server 134 . The interconnection of the presence server to the device management server is well known to one skilled in the art, and is not described in any further detail hereinafter.
[0048] Finally, in a step 208 the device management server 134 resends the appropriate network parameter setting to the terminal, as represented by signal line 136 in FIG. 1 . The parameter is thus automatically reset. The parameter is resent via, for example, over-the-air provisioning, SyncML, smart messaging etc. Various techniques for configuring such parameters in the terminal based on messages from the device management server are known in the art, and therefore are not described in detail herein.
[0049] In alternative arrangements, the presence server 126 may directly reply to the presence client with the correct settings for the parameters in the terminal.
[0050] Alternatively, the presence server may interface with another network element or element external to the network in order to return the correct settings to the terminal.
[0051] The invention thus advantageously provides an automated technique for maintaining the correct parameter settings in a terminal for accessing network services. Operator costs, such as operational cost, services maintenance, call service, helpdesk) are minimised by the automated mechanism.
[0052] The use of presence services clearly provides a particularly advantageous architecture for implementing the present invention, and as presence services are likely to be widely implemented, it is envisaged that an enhanced presence client will provide the most likely application scenario for the present invention.
[0053] However, in general the present invention relates to an automated technique for ensuring correct parameters are maintained in a terminal, and this may be provided by means other than by presence services.
[0054] It should be noted that in certain circumstances the change of a stored setting or parameter by a user may be intentional. In such case there may be no requirement to update the setting.
[0055] In the foregoing, an embodiment has been described in which it is desired to maintain the terminal parameter settings. This is on the assumption that the settings remain valid. It is mentioned above that the user may deliberately alter the settings. An example scenario where the user may deliberately alter the settings is to allow operation in a different operator domain which supports different terminal settings. In a further embodiment of the invention, described below, there is described an automated technique for updating the terminal settings in a handset or terminal as the handset roams into a different operator domain.
[0056] In one arrangement of this embodiment, the presence client 102 of the terminal 100 may be adapted to detect a change of operator domain, e.g. in dependence on a change in location. Alternatively the presence client may monitor the terminal's network connection in order to detect a change in operator domain.
[0057] Responsive to a change in operator domain, the monitor block 118 may be adapted to transmit a presence update to the presence server 126 in the operator domain. Responsive thereto, the presence server 126 may send a request to the device management server 134 to transmit the current terminal settings to the terminal, or reply directly thereto. In this way the presence client may ensure the terminal parameter settings of the terminal are updated whenever the operator domain changes.
[0058] This technique may be provided without the use of presence services. For example responsive to the detection of the terminal being connected in a new operator domain, the terminal may be adapted to transmit a request for a new set of terminal parameter settings to the network.
[0059] An example implementation in accordance with this embodiment is described with reference to FIGS. 3 and 4 .
[0060] Referring to FIG. 3 , to the left-hand side of the dash line 330 there is illustrated the functional elements required in the terminal or handset for the purpose of implementing the example embodiment of the invention. To the right-hand side of the dash line 330 there is illustrated the network environment. The terminal or handset roams, and may connect into any local operator network in its environment. In FIG. 3 , three operator networks are shown: operator network A 324 a, operator network B 324 b and operator network C 324 c. The terminal or handset will be connected into one of these operator networks at any time.
[0061] In the example of FIG. 3 , the terminal is provided with a memory which allows for a plurality of terminal parameter settings to be stored. The memory is generally designated by reference numeral 302 , being a memory for storing a plurality of sets of parameter settings. In the example shown, the memory 302 includes a first set of parameter settings 104 a and a second set of parameter settings 104 b. As with FIG. 1 , each of the set of parameter settings includes the different network specific settings required for the terminal connected to a particular operator network. The settings 104 a are associated with an operator network being identified as “operator A”, and the settings 104 b are associated with an operator network being identified as “operator B”. As in FIG. 1 , each of the sets of terminal parameter settings include various values 106 - 110 , appropriately designated as a or b. As also with FIG. 1 , each of the sets of parameter settings are output on signal lines 112 - 116 , with appropriate designations a or b. In the example embodiment of FIG. 3 , the signals on lines 112 - 116 are input to a select block 318 , and then one set of the signals is provided on an output signal line 112 A- 112 C to the monitor block 118 , which generates a signal on line 320 as in FIG. 1 . Thus it can be seen that select block 318 merely operates, as described further hereinbelow, to present the appropriate set of terminal parameter settings to the monitor block 118 . Only one set of terminal parameter settings is provided for use at any one time.
[0062] Although FIG. 3 illustrates that the memory 302 may be provided with two sets of terminal parameter settings, there may be provided further parameter settings. Alternatively, one set of parameter settings may be a fixed set of parameter settings associated with the terminal's home network, and the other set of parameter settings may be available for temporary storage of the current parameter settings of a visited network.
[0063] The terminal is further provided with a parameter control block 306 , which receives on lines 304 a and 304 b the identities of the network operators associated with the respective sets of terminal parameter settings in the memory 302 . The parameter control block 306 also receives on line 310 the identity of the current network from a current network block 308 . The parameter control block 306 provides an output signal 314 to control the select block 318 , and an output signal 312 . As described hereinbelow, the output signal 312 is a request for parameter settings to the operator network. The terminal receives parameter settings from the operator network as designated by a communication input line 316 which forms an input to the memory 302 . Generally, reference numeral 322 represents the interface between the mobile terminal and the current operator network with which a connection is established, via a radio access network (not shown).
[0064] Each of the operator networks 324 a - 324 c are connected, as discussed further hereinbelow, to a setting server 328 via a respective connection 326 a - 326 c.
[0065] The operation of this embodiment of the invention is now described further with reference to the flowchart of FIG. 4 .
[0066] In a step 400 , the terminal monitors the current operator network identity. The current network identity is stored in the block 308 and provided on line 310 to the parameter control block 306 . Thus the parameter control block 306 , for the purposes of this example, monitors the current network identity.
[0067] If in step 402 the parameter control block 306 identifies a change in the network operator, then there is a requirement to update the terminal parameter settings for the new operator network.
[0068] In a step 404 , the parameter control block 306 determines whether the operator parameters for the new operator network are already available in the terminal. In this respect the parameter control block 306 compares the network identity on line 310 to the operator network identities on lines 304 a and 304 b. If a match is determined, then the parameter control block 306 sets the control signal 314 to control the select block 318 to output the terminal parameter settings for the appropriate network operator. Thus in a step 406 there is made a switch to the appropriate operator parameters for the new operator network.
[0069] It should be noted that different operator networks may well share the same settings, such that one set of terminal parameter settings may be used for multiple operator networks. In such case the operator identity associated with terminal set 104 a or 104 b will include identities of all associated operator networks.
[0070] If the parameter control block 306 determines that the memory 302 does not store a set of terminal parameter settings for the current network setting, then in a step 408 the parameter control block 306 transmits a signal on line 312 in order to request the appropriate set of terminal parameter settings from the operator network. In practice, the signal on line 312 may be a control signal which is interpreted by other functional means within the terminal for transmission to the operator network.
[0071] In a preferred embodiment, there may be provided a single settings server 328 which stores the terminal parameter settings for all operator networks. As such the operator network within which the terminal is currently connected, may forward a request for terminal parameter settings to such settings server, and return a reply from the setting server to the terminal. Alternatively the operator network itself may provide the necessary terminal parameter settings.
[0072] In the present example, it is assumed the terminal has moved to a new operator network, being operator network C 324 c. The radio access network associated with the operator network C receives the request for the new terminal parameter settings, and sends the request on line 326 c to the setting server 328 . The appropriate terminal parameter settings are retrieved and returned, to the operator network C, and forwarded through the radio access network to the terminal. The settings are received on line 316 , and stored in the memory 302 . Step 410 refers to the step of receiving the new operator parameters.
[0073] The operator parameters may be stored in an existing set of terminal parameter settings, i.e. they may overwrite a current set, or may be stored in an available vacant memory space.
[0074] In embodiments, the memory 302 may be provided with sufficient space for only one set of parameter settings, and only one set of parameter settings may be stored at a time. As such, the current set of terminal parameter settings are overwritten by any new set. This will require an update transaction, including an access to the operator network, whenever a mobile terminal enters into a new operator domain. In a preferred embodiment where the memory 302 allows for storage of multiple terminal parameter settings, a network access is not always required, as certain terminal parameter settings are always available in the terminal handset, such as the terminal parameter settings associated with the terminal's home network.
[0075] The request on line 312 for a new set of terminal parameter settings may be processed in any number of ways by the operator network. As discussed in the embodiment of FIG. 1 , the parameter control block 306 may be associated with presence services, and a presence server in the operator domain may provide the terminal parameter settings. Alternatively a device management server in the operator network domain may provide the parameters. The provision of the parameters is an implementation issue.
[0076] In an embodiment, the request on line 312 to access and obtain a revised set of terminal parameter settings may be optional, and via the user interface of the terminal the user may be given the option as to whether the terminal settings should be updated. Such an optional feature may be particularly useful when the memory 302 is able only to store one set of terminal parameter settings. As this will require the overwriting of the default terminal settings for the home network, the user may not always wish to replace the settings. Furthermore as the updating of the settings requires a network access, there may be call charges or data downloading charges associated with the update. If the user will be charged for accessing and retrieving the updated terminal parameter settings, then the option for the user to choose not to update such settings must be provided.
[0077] The embodiment described with reference to FIGS. 3 and 4 may also be used when a mobile terminal is first switched on. For example, if the phone has been switched off, and is now in a different operator network from when it was previously switched on, then the above-identified approach may be used in order to seek and obtain the appropriate terminal parameter settings for the operator network within which the terminal is currently connected.
[0078] As such, this embodiment advantageously provides the user with the ability to automatically access mailbox-accounts, WAP-bookmarks, GPRS and MMS-settings, regardless of the user's location.
[0079] In a preferred embodiment, the request for an update of terminal parameter settings, responsive to the signal on line 312 for the parameter control block 306 , is an SMS message to the setting server 328 . Any embodiments, which implement the present invention, may use SMS messaging in order to seek an update of the terminal parameter settings.
[0080] The scope of the present invention is thus limited by the appended claims, and is not limited to any specific aspect of preferred embodiments described herein.
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There is disclosed a method, and a corresponding apparatus, for maintaining the settings of a user equipment, comprising: monitoring at least one stored setting in the terminal; responsive to a change in said at least one stored setting notifying a controller; and responsive to said notification selectively resetting said at least one stored setting.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method of generating flake particles and to release systems and coated intermediates used in such methods, as well as collections of such flake particles. The invention particularly relates to the production of flake particles of a controlled shape and size for use, for example, in the paints, inks, cosmetics and anti-counterfeiting industries, where such particles may require specific optical, electrical, magnetic or rheological properties.
BACKGROUND OF THE INVENTION
[0002] A variety of prior art methods exist for the manufacture of inorganic flakes ranging from casting methods using water or jets to break up a molten metal stream, atomising methods that atomize and spray molten metal, to mechanical methods such as grinding up of released deposited films. For example, in recent years disc shaped, inorganic, micron scale, flake pigments for commercial ink and paint systems have been made by depositing (e.g. sputtering) a thin inorganic film upon a flexible web substrate that has been treated with a release agent, stripping the inorganic film from the substrate, filtering the released flake so generated and reducing the flake size to the required micron scale, usually by grinding and agitation.
[0003] Applicant's earlier International patent application WO 02/072683 describes a release film system for manufacturing inorganic flake particles which uses an intermediate layer mineral release layer such as vermiculite to assist with release of a deposited film of inorganic flake material from a web substrate. The film can be released in the form of random flakes which are collected and processed to the desired size for use in ink pigments or paint coatings applications. U.S. Pat. No. 5,135,812 is similarly directed to the production of optically variable flakes for use in paints and inks, and teaches the sizing of flakes by methods such as ultrasonic agitation or, for very fine particles, also by using air grinding.
[0004] WO 2006/116641 describes a process for making embossed fine particulate thin metallic flakes where the release surface is embossed with a fine diffraction grating pattern, and then metallised with a metal film which on release by stripping yields flakes on which the diffraction grating pattern with a groove depth of 125-140 nm is replicated. The resulting flakes have an average particle size of about 75 microns after metal stripping which size is maintained by omitting any high energy mixing or particle sizing steps.
[0005] All of the above prior art methods, however, rely upon break up of a deposited film to form flakes of an uncontrolled size and shape, with downstream processing steps used to achieve finer size control.
[0006] EP1741757 describes how opaque flakes with a selected shape are made by coating a flake material on a substrate, embossing frames onto the material or the underlying substrate as lines of weakness, such that when the film is removed the flakes tend to break along the frame lines so that they are substantially uniform in size. It is suggested that only a small portion (e.g. 10%) of the substrate should be so embossed such that a percentage of covert sized flakes are generated. This method still relies on fracture of a film to generate particles and references a loss of yield when processing the embossed portion of the substrate.
SUMMARY OF THE INVENTION
[0007] The present invention provides a method of directly depositing discrete flake particles of a controlled size and shape comprising providing a textured substrate comprising an array of discrete, steep-sided exposed plateaus of a selected size and shape, and depositing a film forming material over the entire array such that it forms discrete, releasable flake particles of a corresponding size and shape on the plateaus.
[0008] The present method allows flake of a controlled size and geometry to be generated directly in large amounts on the plateaus. Preferably, the method includes subsequently releasing and collecting the flakes, whereby the flakes still have the same corresponding size and shape and have not been broken up. The method is readily scalable so as to permit high volume production, for example, by reel to reel processing. The flake may be formed from any suitable film-forming material and may, for example, be inorganic, organic and/or metallic in nature and may be single layered or multi-layered.
[0009] For the flakes to be releasable, the textured substrate should have inherent releasing ability with respect to the type of flake material being deposited, such that the latter is releasable therefrom.
[0010] By “corresponding size and shape” we mean the same or a related, closely similar size and shape.
[0011] While deposition is conducted over the entire array (i.e. non-directionally and without the use of templates), the textured substrate is inherently designed so as to cause discrete flake particle generation. In addition to the controlled geometry, there is the advantage that flakes formed directly as discrete flakes tend to be surprisingly flat. By contrast, flakes formed from continuous films by releasing and sizing operations tend to exhibit curling due to tension effects unless the film deposition is very carefully controlled.
[0012] In a further aspect, there is provided a method of producing shaped flake particles comprising the steps of: —
[0000] a) providing a release system comprising a textured substrate comprising a plurality of discrete, steep-sided plateaus of a selected size and shape, and coated with a film of release agent;
b) producing a coated intermediate by depositing a film of material on the substrate such that it forms discrete flake particles on the plateaus;
c) releasing the discrete flake particles from the coated intermediate.
[0013] Rather than coating the entire substrate as a continuous film, as in the prior art, the release agent film will usually be discontinuous over the substrate, i.e. not continuous, being broken up at the plateau edges and corners.
[0014] The term “plateau” is used herein to refer to a substantially level stretch of substrate of the same height and suitable for forming a deposition area for a flake particle; the area may be a raised/higher area or a sunken/lower area (i.e. valley) with respect to the substrate immediately surrounding it. The plateaus are delimited by steep sides around substantially their entire perimeters such that they are discrete elements i.e. substantially unconnected, and hence, individually distinct. While the plateaus are substantially level that does not exclude the use of raised or lowered motifs or indicia (e.g. diffraction gratings) on the plateaus, which may be desirable for example on flakes used for covert security applications. The array will usually be a regular, ordered pattern and will be designed to maximise yield of flake particles usually through the use of close-packed and/or tessellating plateaus.
[0015] Use of the present release system thus enables the textured substrate directly to define the desired shape, size and even percentage yield of subsequently deposited and released flake particles, without the need for any downstream sizing/filtering processes. Thus, the substrate can be engineered to generate a desired final size distribution in the flake particles upon their initial release. Moreover, because the flake particles can be formed on the discrete plateaus as individual flakes the flakes do not need to have any fracture edges, which can be an important advantage for certain reactive inorganic or metallic materials (e.g. aluminium), as well as improving the reliability of the final shape.
[0016] The use of the textured substrate also enables the production route to be simple; for example, both the release agent and material can be deposited indiscriminately (non-directionally) over the entire active area of the substrate since the steep plateau walls cause their subsequent segregation and confinement on the plateaus.
[0017] The surface of the textured substrate is conveniently formed from an embossed photopolymer.
[0018] In a preferred arrangement, the steep sided plateaus are each coated with a discrete cap of release agent film on top of which cap is deposited a discrete flake of material of a related size and shape (e.g. varying within about 10%). Edge beading of the release agent around its periphery due to surface tension effects is desirable, since the overhang appears to encourage isolation of the subsequently deposited material film as a discrete flake. Other overhanging structures could also be used to encourage discrete flake generation, with or without release agent. For example, an embossed structure could be passed through a hot nip to cause a slight flattening of the tops of raised plateaus, or if a textured structure is produced by a non-embossed method, such as an etching method, then chemical etching could be used to produce rounded overhanging capped plateaus.
[0019] The plateaus are usually delimited by steep side walls having a depth of at least 2 microns. A textured surface with steep walls of at least this depth (as opposed, for example, to the fine detail of a diffraction grating with a typical groove depth of ˜0.1 micron) ensures the coating of the release agent is confined to discrete, designated flat areas (the plateaus), the discontinuous nature of the release film giving rise to correspondingly discrete patches of flake material. More preferably, the plateau depth will be at least 4, ideally at least 5 microns. Preferably, the plateaus will have minimum side dimensions of at least 2 microns, ideally at least 4 or 5 microns to assist flake releasability. Minimum side dimensions of at least 10 microns, however, are usually preferred.
[0020] In certain specific applications where very thin inorganic films of less than 1 micron are being deposited (e.g. optical films of 50-100 nm i.e. up to 0.1 micron), and a thin release agent film is also used, the plateau depth may be at least 1 micron.
[0021] For embossed structures, the side length of any plateaus should preferably be of the same order or greater than the depth/height of the trenches/cliffs between the plateaus; preferably the ratio of the trench/cliff depth to minimum plateau side length is usually at least 1:1, preferably at least 1:1.5 or 1:2. Thus, if an embossed substrate is used, any sunken areas (indentations) in the embossed structures should preferably not be deeper than they are wide, and should be straight sided or flare outwardly towards their opening to permit removal of the embossing shim.
[0022] The relief angle should be such that uniform (i.e. non-directional) application of the release agent does not lead to permanent coating of the steep-sided walls with dried release agent or flake material, which might lead to a continuous film of flake material and prevent the subsequent release of discrete flake particles. A relief angle of between 0° and ±40° to the substrate normal (vertical), preferably up to ±25°, will be used depending on the technique for fabricating the texturing. While other texturing techniques may employ negative angles (concave trenches), embossed structures can only use+angles (to allow shim removal) and will preferably be in the range 0-25°, more preferably, 5-20°.
[0023] Flake generating plateaus may form at least 25% of the active area. The present method enables high shape yield efficiency of target particle shapes and is readily scalable for high volume production using continuous substrates with widths for example of the order of 0.3 m-2 m widths.
[0024] By “active area”, it is intended hereinafter to refer to that part of the substrate where it is intended to carry out deposition and subsequent flake generation. For example, in a continuous substrate used for reel to reel processing there may be front and end sections, intermediate “rest” sections, as well as side sections, that may not be used specifically for shaped flake generation. The active areas and inactive areas may be textured and untextured, respectively, but there may be circumstances where an area is still textured but is inactive, for example, due to apparatus incompatibility issues.
[0025] In the method conveniently at least half of the active area of the substrate comprises raised plateaus suitable for flake production, preferably with a minimum side dimension of at least 5 microns.
[0026] Preferably, the substrate is arranged such that flakes are only generated from raised plateaus, since these usually provide the most effective release surfaces; these raised plateaus may form a significant part of the active area, preferably at least 50% or 60%, or even 70% thereof, and may be the only intended shaped flake generation areas. The raised plateaus may be arranged in a close packed array and ideally should not be interconnected, although some bridges at vertices may be unavoidable.
[0027] Alternatively, the active area of the substrate may comprise raised and sunken plateaus in a close-packed array, each preferably having a minimum side dimension of at least 3 microns. In a preferred arrangement, about half the active area comprises raised plateaus and the other half comprises sunken plateaus, preferably abutting and alternating with one another so that there are no other “grid-lines” dissecting the substrate, and preferably with equal sized raised and sunken plateaus.
[0028] However, in some instances, the active area may be arranged with the surface area consisting of all raised (or all sunken) plateaus divided up by a much narrower, interconnecting network of flat, sunken (or raised) areas that may also generate useful fine particles. Such an interconnecting network may be required to surround complex and/or irregular plateau shapes (e.g. logo-shaped plateaus).
[0029] Advantageously, immediately after release the flake particles are of a corresponding size and shape in two dimensions to the selected size and shape of the plateaus and typically will be subsequently collected still in that form in a formulation. However, in a less preferred embodiment, flakes may be released and broken up into random or selected smaller sizes in one dimension, while retaining the width of the plateaus in the second dimension. For example, plateaus intended for flake generation may be in the form of elongate ribs i.e. having one side length that extends continuously across the length or width of the substrate (especially an elongate web substrate) or active area thereof. In that case, the ribs may be provided, at regular repeat intervals along their length, with protruding notches forming “waists”, or with dissecting bar lines of raised or lowered micron (e.g. 0.1-2 micron depth) relief, that represent lines of weakness that will facilitate the subsequent fracture of the elongated flake particles at the desired respective repeat intervals either upon stripping or during subsequent sizing operations. The present method has been shown to be capable of replicating such notches or relief features.
[0030] The active area may be textured with raised and/or sunken plateaus of the same geometry where a substantially mono-modal distribution is required. Where multi-modal distributions are required, the active area may be textured in the form of significant selected proportions of different geometric types of shaped flake generating plateaus, i.e. each type being of a different specific size and shape, so as to give rise to corresponding selected proportions of flakes of the different geometries.
[0031] In the release system the textured substrate may have one of the following configurations: —
[0000] i) the active area of the substrate is formed predominantly of raised plateaus segregated by an interconnecting grid network of lower trenches;
[0032] The present invention has the flexibility that it allows a huge variety of different shaped flakes to be generated and this particular arrangement with the interconnecting network can be used to surround any complex, irregular or non-tessellating plateau shapes. Preferably plateau dimensions are at least 5 microns, or even 7 microns and preferably at least 10 microns, to assist release.
[0033] To achieve high theoretical “shape yield” efficiencies, the plateaus should be close packed with narrow trenches, thereby maximising the yield of useful flake particles.
[0000] ii) the active area of the substrate is formed predominantly of an alternating chequerboard of raised plateaus and sunken plateaus.
[0034] This design provides release from the top and bottom of the substrate and hence has the potential to generate high yield efficiencies. It can even be used for small lateral particle dimensions of less than 10 or even 5 microns, although very small dimensions may mean release is only effective from raised plateaus leading to a yield efficiency of 50%. The plateaus comprise any suitable tessellating shapes (i.e. ones that fit together without leaving gaps), which may, for example, be regular or irregular, and may be straight-edged shapes such as squares, rectangles, hexagons, triangles, or diamonds, or curved tessellating shapes such as teardrops. The raised and sunken plateaus are usually all of the same size and shape, for example, where the walls are near vertical, but may be of a slightly differing size and shape, for example, with less steep walls, although the regularity of the chequerboard and preferably the segregation of the raised plateaus should be maintained.
[0035] Where textured substrates are produced using embossing shims, resulting in a loss of lateral definition, a “handedness” can be created for small dimensions leading to tiny interconnections or small gaps between neighbouring raised plateaus (which abut at their corners); the latter are preferred, since they still allow effective release of discrete particles from the raised plateaus.
[0000] iii) the substrate is formed predominantly of alternating raised plateaus and sunken plateaus in the form of continuous ribs and continuous trenches, respectively.
[0036] This design yields released discrete flakes of the selected rib width and may be preferred where high aspect particles are required. The design provides high yield efficiency in that release occurs equally from both ribs and trenches. The ribs may have pre-defined, selectively spaced, lines of weakness such as notches that encourage the flake particles to fracture into selected flake lengths after release, or the ribs may fracture randomly into flake of variable lengths, optionally with the subsequent use of ultrasonic agitation or similar methods to achieve the desired size. The ribs and trenches will usually be of equal size and shape and parallel; they may extend across the whole width (or length) of the substrate or over a large fraction thereof.
[0037] The substrate may include fine 3D relief features such as ID motifs or indicia provided upon the shape generating plateaus, for example, where covert flakes are required for security or anti-counterfeiting applications.
[0038] The choice of substrate will depend on which technique is selected to create the 3-D texturing. Ideally, a continuous web suitable for use in reel to reel processing may be used that can withstand the downstream deposition and release stages needed to generate the flake. Where an embossed substrate is used, a PET substrate is suitable as long as processing temperatures are not excessive. Other polymer substrates might include polyester, polypropylene, polyethylene, polyethylene naphthanate, polyether sulphone, polybutene, olefin copolymers, polyamide, polyimides, polycarbonate and polyacrylonitrile. The substrate may have an overlay of a relief forming polymer, preferably, an embossable photopolymer. WO 96/35971 describes a method of preparing such a micro relief element with the three-dimensional structures described therein having repetitive patterns protruding above the substrate. Other methods of creating textured substrates could use other web materials such as metal foil substrates, these being suitable for example for producing flakes of material which need to be deposited at high temperatures.
[0039] The release agent is preferably selected so as to cause release of the flake particles when the substrate is immersed in an aqueous medium, optionally with flexing and/or agitation. A release agent that disperses/dissolves in water and hence can be applied as a water-based solution and that is also stripped using water as the stripping solvent is highly preferred for environmental reasons. While release agents that can be applied as water-based solutions are preferred, additional steps or pretreatments may be needed to encourage them to “wet” the embossed substrate, which will usually be polymeric, properly due to surface tension effects. Release agents that can be applied and stripped using organic solvents may also be used, often without needing such wetting pretreatments. An example of one suitable such organic-solvent compatible release agent would be PMMA.
[0040] In a preferred embodiment, the release agent is a clay mineral. Phyllosilicates or sheet silicates form parallel sheets of silicate tetrahedra and an important group within the phyllosilicates is the clay mineral group. By the term “clay mineral” we intend to cover both natural and artificial clay minerals. The clay mineral group (also known as layer minerals) includes natural clay minerals such as kaolinite, illite, smectite, montmorillonite, hectorite, vermiculite, talc and pyrophyllite, and synthetic clay minerals, for example, synthetic smectites such as Laponite®. In this invention the use of (2:1) phyllosilicates with an octahedral sheet sandwiched between two tetrahedral sheets is preferred, especially the “swelling clays”. Such clay minerals contain large percentages of water trapped between the silicate sheets and can readily absorb or lose water leading to significant expansion or contraction as the water fills the spaces between the stacked silicate layers. Hence, once the textured substrate is exposed to water and this comes into contact with a release agent layer of clay mineral, rapid swelling and delaminating of the release agent layer permits ready release of the flake particles. The release (in normal water or preferably, deionised water) is rapid and efficient and indeed, so comprehensive that there is the possibility of re-using the textured substrate after minimal cleaning. Since the clay minerals can be applied as a water-based solution using roll-to-roll methods such as bead coating, the application of the release coating can form part of a reel-to-reel process.
[0041] Clay minerals are also fine grained (normally considered to be less than 2 microns in size), and the fine grains or platelets are desirable for maintaining the fidelity of embossed features and minimising disruption to the overcoated layer. Clay minerals with platelet sizes of less than 100 nm are especially preferred. Laponite® tends to form disc shaped crystals of ˜1 nm by 25 nm, and this is smaller than for example a bentonite platelet (˜300 nm).
[0042] Other water-soluble, film-forming materials known in the art that could be used include polymers such as, for example, vinyl acetate type resins, polyvinyl alcohol (PVA), polyethylene oxide, polyacrylamide, or polyvinylpyrrolidone. Another suitable “water soluble” type release agent is Borax (also known as sodium borate, sodium tetraborate, or disodium tetraborate). The film-forming material needs to exhibit suitable adherence to the selected embossed substrate, as well as suitable releasing ability, and also exhibit good coverage as a film without retraction.
[0043] The flake forming material may be any suitable film forming, preferably vacuum or vapour depositable, material; the material may be inorganic, organic or metallic and may especially be ones used in the production of thin film pigment flake. The invention is especially suitable for producing flat shaped flakes, particularly ones with specialised optical properties (e.g. highly coloured and/or reflective) and/or specialised magnetic properties and/or specialised electrical (or electro-optic) properties e.g. flakes for thermochromic coatings.
[0044] The material will usually be metallic or inorganic. It may be a metal or a metal containing material or an inorganic compound, the latter usually being a metal containing compound, and by way of example the material may be an alloy, an intermetallic, dielectric, semiconductor or a glass. An organic material such as PTFE could also be deposited (e.g. sputtered). The flake may be made from a single layer or from multilayers of any of the above materials, for example with outer upper and lower protective coating layers, for example, inorganic barrier layers such as SiO 2 or Si 3 N 4 , or organic layers such as PTFE.
[0045] Typical metals include aluminium, chromium, magnesium, copper, vanadium, nickel, zinc, tin, silver, gold, titanium, silicon, bismuth or indium. Bright metals such as, for example, silver, aluminium, copper, indium and nickel are typically used to produce pigment flakes with high levels of brightness and colour intensity for use in coatings and printing inks. The metallic material may also be an alloy (for example, of the afore-mentioned metals, e.g. an aluminium alloy, Ag—Au alloy, etc), which may be magnetic (hard or soft) or non-magnetic, an intermetallic or any other suitable metal-containing compound. Soft magnetic alloys may be used, for example, for generating anti-counterfeiting pigments and suitable commercially available alloys include CoFeSiMoB, CoZrNb and Permalloy (Fe 0.2 Ni 0.8 ). Deposited materials may also be dielectrics or semi-conductors and typical examples of inorganic compounds may include oxides (e.g. VO 2 ), nitrides, fluorides and carbides.
[0046] On the coated intermediate, the discrete flakes comprise a single deposited layer or sequentially deposited multilayers of film forming materials, the multilayers being selected from the same or different materials. The use of selected upper and lower layers can provide some three-dimensional control with, for example, protective or passivating layers employed to form an outer coating.
[0047] The present invention is especially suitable for providing flake particles having a thickness of 0.01 microns-10 microns and a diameter (average side length) of 3 microns to 300 microns, up to a preferred maximum of 1 mm. For paint applications, flake particles will normally be of the order of 1 to 60 microns.
[0048] In a preferred method, step a) includes a step of manufacturing the initial textured substrate comprising a plurality of discrete, steep-sided plateaus of a selected size and shape. This may be by reel to reel processing and may involve embossing the substrate, for example, embossing a UV curable embossable photopolymer superstrate supported on a substrate. Step a) may also include a step of applying a release agent solution and drying the same to form the coated release agent layer.
[0049] The substrate of step a) may already have been subjected to a wetting treatment to improve its subsequent wetting by the release agent or step a) may actively include such a wetting treatment step; these steps are usually necessary where water-soluble release agents are to be used. Alternatively, or, additionally, step a) may include applying a release agent solution that includes a wetting agent in order to improve wetting of the substrate by the release agent. As a result the release agent film “wets” the substrate surface on the plateaus as a continuous film. This may be achieved by a corona discharge treatment (also known as plasma discharge) of the embossed substrate prior to the application of the release agent, and/or by use of a wetting agent such as a surfactant in the release agent coating solution. Other techniques for achieving wetting of the substrate by the release agent will be known to the skilled person. The wetting treatment should result in a complete, continuous cap of release agent on the plateaus preferably with edge beads forming around the perimeter of the caps of release agent film; these edge beads are believed to be important and form both on raised plateaus and sunken plateaus, while the vertical or near vertical side walls remain uncoated with release agent. The formation of the edge bead appears to create a shadowing effect which leads to the flake particles being generated as separate individual islands. This discontinuity may also facilitate release of shaped particles, particularly in the case of a water soluble/water-swellable release agent such as a clay mineral.
[0050] The deposition of the metallic or inorganic film can be carried out by methods that cover the entire active area of the substrate (rather than requiring localised deposition methods such as electrodeposition). Deposition does not need to be restricted to the plateau areas using, for example, shielding or templates because their relief causes discrete flake generation thereon. The film can be deposited by any suitable methods, and preferably those based on vacuum or vapour deposition, and these may include chemical vapour deposition (CVD) methods or physical vapour deposition methods (PVD) such as sputtering, thermal evaporation, ebeam evaporation, spraying or similar methods.
[0051] In thermal evaporation the coating metal is joule heated, under high vacuum, in a crucible to beyond its melting point after which it evaporates and will coat a substrate placed above the crucible. In sputtering a target material is, under partial vacuum, subjected to bombardment from heavy ions (usually Ar) in an ionised gas. The target is eroded and the liberated material then coats a substrate placed close to the target.
[0052] The material is deposited as a thin film of one or more material layers, which may have a total depth in the range of 0.05 to 10 microns, more usually less than 3 microns.
[0053] Step c) may comprise stripping the particles by flexing the substrate, preferably around one or more rollers, or planar-faced bars, and may also include agitation and/or filtration. Preferably, the substrate is immersed in tap water or deionised water, flexed, and exposed to an ultrasonic bath. Release of discrete flakes of the desired size is usually surprisingly good, such that downstream processing is unnecessary. If required, however, agitation may assist in breaking down any undesired bridges and/or reducing particle sizes, while simple filtration may remove undesired smaller or larger or irregular particles, for example, undesired sprues or large connected irregular particles.
[0054] For high volume production, the method may be conducted using an elongate flexible web substrate in a reel to reel process.
[0055] The process may be conducted batch-wise or continuously. The processing may incorporate re-use of the substrate after a cleaning step fully to remove any remaining release agent coating and/or deposited inorganic material.
[0056] In a further aspect, the present invention provides the use of a textured substrate or release system as specified above to generate flake particles of a controlled shape and size.
[0057] There is further provided, in another aspect, a novel coated intermediate comprising a textured three-dimensional substrate having an array of discrete, steep-sided plateaus of a selected size and shape and coated with a discontinuous film of release agent, on top of which is deposited a discontinuous film of material in the form of releasable flake particles. The steep sided plateaus are preferably each coated with a discrete cap of release agent film on top of which cap is deposited a discrete flake of material of a related size and shape.
[0058] Additionally, the present invention provides a novel release system for use in the above method comprising a textured substrate comprising a plurality of discrete, steep-sided plateaus of a selected size and shape, and coated with a discontinuous film of release agent that forms a discrete cap of release agent film on each plateau of a corresponding size and shape to that plateau.
[0059] In a further aspect, there is provided a novel collection of flake particles, preferably in a liquid formulation that is water or organic solvent based, said particles being obtainable or obtained according to the methods described above, wherein most of the particles fall into one category of a particular size and shape, or several such distinct categories, the particles in any one category being substantially identical under microscopic examination.
[0060] The flake particles may be single layered or multilayered, and any such layers may be of the same or different composition. The flake particles are characterised in that under microscopic examination it will immediately be evident that they clearly fall into identical size and shape categories e.g. clearly a unimodal/bimodal/trimodal etc distribution and are formed by the present templating method. The particles are also preferably characterised by edges that have not been fractured, for example, by grinding or agitation. The size/shape distribution will follow that of the respective relief features of the active deposition areas of the substrate.
[0061] Variation of side lengths within a category will be very small, with occasional bridging or interconnecting of plateaus across commonly shared side edges or vertices. Each category will be readily identifiable as such, since the technique is robust in replicating the respective plateau configurations and percentage distributions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0062] The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: —
[0063] FIG. 1 is a schematic flow diagram for a process for manufacturing thin film shaped flake particles according to the present invention;
[0064] FIG. 2 is a schematic cross-section through an embossed substrate overcoated with release agent and an inorganic (or metallic) thin film;
[0065] FIG. 3 is a flow diagram illustrating the main steps of a process for manufacturing shaped flake particles according to the invention;
[0066] FIG. 4 is a schematic flow diagram illustrating the steps conducted with respect to a substrate for a preferred process of manufacturing shaped flake particles;
[0067] FIGS. 5 a , 5 b and 5 c are respective schematic diagrams of three alternative grid/rib/chequerboard textured substrate designs;
[0068] FIG. 6 is a schematic diagram showing three alternative sets of dimensions for the grid substrate design of FIG. 5 a;
[0069] FIG. 7 a is a schematic diagram of a specific grid ( FIG. 5 a ) embossed substrate design with 5 μm×50 μm plateaus (5 μm wide×5 μm deep trenches), FIG. 7 b is an SEM micrograph of the corresponding embossed photopolymer substrate, and FIG. 7 c is an SEM micrograph of the same after coating with a release agent layer;
[0070] FIGS. 8 a , 8 b are SEM micrographs of a 50 μm×100 μm plateaus (5 μm wide×5 μm deep trenches) embossed photopolymer substrate of the FIG. 5 a grid design, and FIGS. 8 c , 8 d are SEM micrographs of the same after coating with a release agent layer;
[0071] FIGS. 9 a and 9 b are optical micrographs of 5 μm×50 μm and 50 μm×100 μm shaped flakes released from the substrates of FIGS. 7 and 8 , respectively;
[0072] FIG. 10 a is a schematic diagram of a continuous rib, 5 μm width/repeat, embossed substrate design, and FIG. 10 b is an optical micrograph of a corresponding substrate;
[0073] FIG. 11 a is a schematic diagram of a continuous chequerboard, 10 μm×50 μm plateaus, embossed substrate design, and FIG. 11 b is an optical micrograph of a corresponding substrate;
[0074] FIG. 12 a is a schematic diagram of a continuous chequerboard, 5 μm×50 μm plateaus, embossed substrate design, and FIG. 12 b contains two optical micrographs of the released shaped flakes;
[0075] FIG. 13 is two SEM micrographs of a Permalloy and release agent (with surfactant additive) coated 5 μm×50 μm chequerboard substrate;
[0076] FIG. 14 is two SEM micrographs of a Permalloy and release agent (without surfactant additive) coated corona treated 5 μm×50 μm chequerboard substrate;
[0077] FIGS. 15 a and 15 b are, respectively, optical micrographs of released Permalloy particles from a surfactant treated substrate and a corona treated substrate;
[0078] FIG. 16 is two SEM micrographs of a ˜3 μm×50 μm chequerboard embossed web;
[0079] FIG. 17 is two SEM micrographs of an Atalante® CoFeSiMoB film and release agent (with surfactant) coated substrate;
[0080] FIG. 18 is an optical micrograph of the released Atalante® CoFeSiMoB film particles;
[0081] FIG. 19 is two SEM micrographs of an Atalante® CoZrNb film and release agent (with surfactant) coated substrate;
[0082] FIG. 20 is two optical micrographs of the released Atalante® CoZrNb film particles;
[0083] FIGS. 21 a and 21 b are respectively, SEM micrographs of Borax coated embossed substrates with wetting treatments of (a) surfactant and (b) corona;
[0084] FIGS. 22 a and 22 b are, respectively, SEM micrographs of Polyacrylamide coated embossed substrates with wetting treatments of (a) surfactant and (b) corona;
[0085] FIG. 23 is an SEM micrograph of a PMMA (LG156) coated embossed substrate;
[0086] FIGS. 24 a and 24 b are, respectively SEM micrographs of Borax released shaped particles of (a) thermally evaporated Al and (b) ˜1 μm thick sputtered permalloy:
[0087] FIGS. 25 a and 25 b are, respectively, SEM micrographs of Polyacrylamide released shaped particles of (a) thermally evaporated Al and (b) ˜1 μm thick sputtered permalloy;
[0088] FIGS. 26 a and 26 b are, respectively, SEM micrographs of PMMA released shaped particles of (a) thermally evaporated Al and (b) 1 μm thick sputtered permalloy; and,
[0089] FIG. 27 is a schematic diagram of apparatus for stripping the inorganic shaped flake particles.
DETAILED DESCRIPTION OF THE INVENTION
[0090] Referring to FIG. 1 , this illustrates the main steps in a process for manufacturing shaped flakes according to the invention, namely: —
providing a release system with a textured substrate; depositing a film of material to produce a coated intermediate; releasing the discrete flake particles.
[0094] By way of example, FIG. 4 shows a schematic flow diagram illustrating the steps of a preferred process for manufacturing shaped flake particles such as, for example, micron scale, metallic or inorganic flake pigment that could be used in formulations in the cosmetics or security industries. The process allows flake of controlled size and geometry to be produced directly and rapidly, and is readily scalable for high volume production.
[0095] The process requires a textured three-dimensional substrate with steep-sided plateaus, which could be a single material, but will usually be a textured (e.g. embossed) superstrate layer bonded to a substrate web. The ability to manufacture flake pigment of a specific, pre-determined geometry and size is dependent on the ability to engineer a correctly patterned surface on the substrate. One way of achieving this is to use the technique of micro-embossing where a master shim is used to impart a defined pattern into a photopolymer which is then “frozen” by exposure to ultraviolet radiation; preferably, the photopolymer will be bonded to a UV transparent, polymeric web substrate. The micro-embossing technique can be a reel-to-reel process and therefore inherently suited for the fabrication of very large areas of textured substrate. The preparation of such embossed structures is described for example in WO 96/35971 in the name of Epigem, which relates to the production of micron scale relief structures for generating optical structures, MIM devices, etc. Other ways of generating embossed structures would include the hot embossing of a meltable substrate (e.g. thermoplastic), as opposed to using a secondary photopolymer layer. Other non-embossing techniques for forming textured substrates will also be known to the skilled person, for example, laser micromachining, chemical etching or other suitable surface micromachining techniques.
[0096] An example of such a textured substrate is shown in FIG. 8 b where the photopolymer has been embossed to create 50 μm×100 μm plateaus features separated by 5 μm wide×5 μm deep trenches.
[0097] Depending on the nature of the textured/embossed layer and the release agent, it may then be desirable to conduct a wetting treatment upon the embossed layer, for example, a corona discharge treatment and/or employ a wetting agent in the release agent solution.
[0098] To ensure that the deposited film can be easily removed from the substrate, a coating of a release agent is next applied (unless exceptionally, the textured structure has inherent release properties). Such a release agent may comprise a dispersion of the synthetic clay mineral Laponite in water. This dispersion is applied to the substrate and then dried which results in a thin coating of Laponite predominantly on raised and lowered plateaus.
[0099] In the next step, the film, usually a metallic or inorganic film, is laid down or deposited by any suitable process, and preferably by a vacuum deposition process e.g. sputtering. Sputtering is a form of PVD in which the desired film condenses from a vapour created by bombarding a target of the desired composition by excited atoms of an inert gas.
[0100] FIG. 8 d shows the same embossed 50 μm×100 μm plateaus substrate with an overcoat of the Laponite release agent. It can be clearly seen that an edge bead, or overhang, has formed at the edge of each plateau, most likely due to surface tension effects. Additionally the release agent is largely absent from the sidewalls of the plateaus structures and again it is postulated that surface tension effects force the aqueous release agent solution to separate out and coat either the top of the plateaus or the base of the trenches. This is depicted schematically in FIG. 2 , which also shows the subsequent overcoating of the film. It is believed that that overcoating of film may be interrupted by the edge bead which assists in defining the particle (and sprue) shape and also allows the release solvent access to the release agent.
[0101] After overcoating with the metallic or inorganic film, the coated substrate is then immersed in a suitable solvent, water in this case, which dissolves the release agent layer and with the aid of ultrasonic agitation releases the overcoating of film from the substrate. Where necessary, filtration to remove undesired residues or unwanted for example smaller sprue particles may be conducted.
[0102] FIG. 3 shows a preferred industrial process for manufacturing shaped flake particles, which may include the initial step of fabricating the embossed substrate in-house and also includes a recycling step of cleaning and re-using the substrate, where especially good release by the release agent is exhibited.
[0103] Typically, a preferred industrial process will have the following steps: —
[0000] 1. Treatment of the temporary, flexible (e.g. polymeric) web substrate to create a textured surface in polymer by embossing—for example by microembossing a photopolymer thereon.
2. Treatment of the embossed surface to improve its wettability for overcoating with a release agent solution—for example either a corona treatment or alternatively by addition of a suitable surfactant to the release agent solution.
3. Treatment of the temporary, flexible (e.g. polymeric) web substrate with a suitable release agent.
4. Reel-to-reel deposition of a thin film (or films) onto the treated web using vacuum technology based on Physical Vapour Deposition (PVD—commonly referred to as sputtering), thermal or ebeam evaporation, chemical vapour deposition or other suitable method.
5. Reel-to-reel stripping of the flakes by dissolving the release agent in a suitable solvent, with the aid of ultrasonic agitation if necessary.
6. Filtration to separate the released flake pigment from the release agent residues and web substrate.
7. Flake sizing check using laser diffraction and/or image analysis to verify optimum particle size/size distribution achieved.
[0104] Referring to steps 5 to 7 above, stripping may be carried out by any suitable known technique, batchwise or in a continuous fashion, and with a preferred method being passing the web substrate through a solvent bath using a wind-up roller. In a preferred method, the substrate carrier is passed around a small radius rod, while immersed in a water bath, with ultrasonic agitation. A suitable apparatus is shown in FIG. 27 . After stripping, the flakes will usually be correctly separated and of the desired shape and size. However, in certain instances, downstream processing may still be desirable and the flakes may be subjected to separation, filtering and flake sizing processes as would be known to the person skilled in the art. For example, initially filtration may be carried out to separate the released flake from the release agent residues and web substrate. Flake separating operations may include various solvent filtering and drying stages, and may also involve gravity sedimentation, since the flakes will settle in most solvents. Flake sizing operations may include filtering, and agitation and grinding steps, as known in the art. Flake sizing may be checked using laser diffraction and/or image analysis techniques to verify the optimum particle size/size distribution has been achieved.
Description of Preferred Textured Substrates
[0105] FIGS. 5 a , 5 b and 5 c are respective schematic diagrams of three alternative grid/rib/chequerboard textured substrate designs that are especially preferred and that will be discussed in turn.
[0106] Referring first to FIG. 5 a , which shows the grid design, the active area of the substrate is formed predominantly of a repeat pattern of raised plateaus of equal size and shape segregated by an interconnecting grid network of lower, narrower trenches.
[0107] This design gives higher “shape yield” efficiencies for the larger plateau sizes (relative to the trenches) and good release. The trenches should be as narrow as possible to maximise the yield of useful flake particles. However, even narrow trenches are likely to be coated with a release film, and hence, narrow flake particles, giving rise to a released sprue network of flake particles. Such a sprue network may, however, yield useful high aspect particles and these, if interconnected, may also be broken up by ultrasonic agitation to produce particles of useful dimensions.
Example 1
Grid Design Substrate
[0108] As shown pictorially in FIG. 6 , three different substrates using the grid substrate design of FIG. 5 a were selected for testing, namely: —substrates with plateau sizes of 5 μm×50 μm, 50 μm×100 μm and 10 μm×50 μm, respectively. The wall angle of the plateaus was designed to be ˜18° from the substrate normal. A trench depth of 5 μm and a trench width of 5 μm was chosen for all designs, which gave nominal shape generation efficiencies of 46%, 87% and 61%, as summarised in Table 1.
[0000]
TABLE 1
Particle size (μm × μm)
5 × 50
50 × 100
10 × 50
Particle area (pm 2 )
250
5000
500
Shape yield (%)
46
87
61
[0109] Flat bed embossed substrates were prepared from master embossing shims using an embossable photopolymer resin on a PET substrate. FIG. 7 a , for example, shows the grid embossed substrate design with 5 μm×50 μm plateaus (5 μm wide×5 μm deep trenches). Initially, only the 5 μm×50 μm and 50 μm×100 μm embossed substrates were produced and examined by SEM; the results are shown in FIG. 7 b and in FIGS. 8 a/b , respectively. The SEM's illustrate the excellent definition obtained by the process. On both structures, but particularly noticeably on the 5 μm×50 μm structures, there is some rounding of the corners of the plateaus—an effect resulting from the particular photolithographic technique used to fabricate the master embossing shims.
[0110] The surface of the cured embossing resin was then plasma treated in order to improve the wettability for coating with the release agent solution. A suitable water based, release agent formulation for coating onto the embossed substrates was chosen comprising an aqueous solution of the synthetic clay Laponite, optionally also with the surfactant Synperonic 91/6. This was applied and dried to form a coating of about 0.5 microns thickness
[0111] Referring to FIGS. 7 c and 8 c/d , respectively, these are SEM's of the subsequent release agent coated 5 μm×50 μm and 50 μm×100 μm embossed substrates. They illustrate the “edge bead” type overhang of the release agent coating at the edge of the plateaus and also at the edge of the trenches which is thought to be important in aiding release. The formation of this overhang is thought to be due to surface tension separating out the release agent solution as it dries and forcing it to ‘snap’ onto the plateaus and into the trenches leaving the side walls with little or no coating and also creating a re-entrant structure which may create a break in the subsequently sputtered metal film.
[0112] The flake particles were then generated directly, in situ, on the substrates by sputtering a metallic film of Permalloy film (Ni 0.8 Fe 0.2 ) to a 1 μM thickness. Subsequent to coating with the 1 μm film of Permalloy, the coated substrates were subjected to a standard stripping regime whereby they were bent round a tight radius, and then immersed in tap water with ultrasonic agitation.
[0113] FIGS. 9 a and 9 b are optical micrographs of the 5 μm×50 μm and 50 μm×100 μm shaped flakes released from the substrates of FIGS. 7 and 8 , respectively. The target flakes exhibit a monomodal size distribution. The largest flake size 50 μm×100 μm particles released very well and exhibited excellent shape definition and a monomodal size distribution as shown in the SEM of FIG. 9 b . In addition to the design shape released from the plateaus areas on the substrate, there was also a proportion of sprue material released—strips around 5 μm wide that result from release of interstitial released flakes from the bottom of the embossed trenches. These were sufficiently different in size to the design flakes that they could be straightforwardly filtered out, if not required.
[0114] The 5 μm×50 μm fibres also released well but slightly less readily, with a slightly smaller fraction of the fibres coming off the substrate and a slight tendency to release as small blocks of say four or five still joined particles. This may be due to the high perimeter/area ratio (almost 4× greater than for the 50 μm×100 μm flake) resulting in the fibre having less weight to enable it to pull free or might merely have been due to the fact that the process was at an early stage of development. In addition, during the fabrication of the embossed substrates a degree of stiction was found to occur on the 5 μm×50 μm samples, probably due to a combination of the emboss depth (5 μm) and the low plateau area to emboss area ratio.
[0115] Accordingly, the intermediate size 10 μm×50 μm substrate was produced and flake particles also generated therefrom. Release trials using embossed substrates with this intermediate plateau size, but the same emboss depth as used previously, were successful in providing good yield of the target particle size, and an increase in shape generation efficiency from 46% to 61%, as well as significantly reduced stiction between the shim and photopolymer.
[0116] The grid design was therefore found to be effective in generating thin film flake of a precisely controlled size and shape. While interstitial material from the base of the trenches has also been released, since this is very different in size/shape to the target flakes it can be straightforwardly filtered off and either retained, if a useful size/shape, or discarded. Certainly it may be possible to engineer the embossed substrate to give usefully shaped & sized flakes which are released from both the top and bottom of the embossed relief.
Example 2
Rib/Chequerboard Textured Substrate Designs
[0117] The necessary presence of the trenches in the grid design decrease the shape yield efficiency for smaller flake sizes, and hence, an alternative design was devised that was capable of higher efficiency for smaller flake sizes.
[0118] Two alternative embossed substrate designs were devised. These trial designs are termed continuous rib and chequerboard patterns and are illustrated schematically in FIGS. 5 b and 5 c , respectively. The continuous rib design makes the plateaus continuous in the long dimension and rely on subsequent processing to break the released strips of material into fibres of around the required size. Alternatively, notches or transverse, raised or indented cross-bars may be incorporated at regular intervals along the ribs during micro-embossing to provide lines of weakness. In addition the trenches (lowered plateaus) are similarly sized to the raised plateaus and, assuming that sprue material is released, would contribute equally useful material—thereby potentially increasing the particle generation efficiency from the substrate.
[0119] In the second design comprising the chequerboard, the sprue framework is again dispensed with, and the design aims to generate equal sized particles of the required final geometry directly using raised and sunken plateaus of equal dimension alternating in two orthogonal directions in the plane of the substrate. It was hoped that this would encourage the release of particles of the required shape and size from both the top and bottom of the substrate.
[0120] Embossed substrates, of the two designs, were manufactured with a target emboss depth of 5 μm, into a 10 μm thick overcoat of uv curable resin coated onto a flexible 36 μm thick PET substrate. FIG. 10 a is a schematic diagram of a continuous rib, 5 μm width/depth/repeat, embossed substrate design, and FIG. 10 b is an optical micrograph of the corresponding embossed substrate where the ribs were about 12 cm long. Similarly, FIG. 11 a is a schematic diagram of a chequerboard, 10 μm×50 μm plateaus, embossed substrate design, and FIG. 11 b is an optical micrograph of the corresponding embossed substrate. The emboss quality was excellent with both designs having an emboss depth close to the design value of 5 μm.
[0121] FIG. 12 a is a schematic diagram of a further, continuous chequerboard, embossed substrate design with smaller, 5 μm×50 μm plateaus. A corresponding substrate of this design was similarly manufactured. This led to the following variants being available for particle release studies: —
5 μm trench, 5 μm plateau continuous rib 10 μm×50 μm chequerboard 5 μm×50 μm chequerboard—motif raised * (small gaps between plateaus) *While all designs are symmetrical at the photomask stage, assymetries tend to be introduced into the chequerboard pattern due to imperfections in the photolithography process—principally the rounding of sharp corners—resulting in either minute connections or gaps between plateaus depending on the sex of the embossing shim.
[0125] The test substrates were coated with a release agent formulation using a Meyer bar (or K-bar) to give a ˜12 μm wet coat thickness and a corresponding dry coat thickness of ˜0.5 μm. The formulation comprised Laponite, and a polymeric surfactant in order to aid the wetting of the solution onto the substrate. A 1 μm thickness of Permalloy (Ni 0.8 Fe 0.2 ) was then sputter coated onto the substrates.
[0126] Small scale stripping of the coated substrates was carried out using a bench top ultrasonic bath. First the coated substrate was bent through a tight radius rod to aid release, before being placed in a beaker of tap water which was then placed in the ultrasonic bath. The water serves to re-hydrate the laponite coating, which reverts from a solid dry film to a suspension, while the ultrasonic agitation is intended to encourage the shedding of the shaped particles. The results of the release study are summarised in Table 2 below.
[0000]
TABLE 2
Summary of release study results for different substrate designs
Sample
Number
Format
Observations
EP154/8/11
5 μm
Excellent release of Permalloy film
Flake 1
continuous rib
from both plateaus and trenches on the
substrate as variable length 5 μm width
flakes. Some curling up of flakes.
EP154/8/12
10 μm × 50 μm
Excellent release of Permalloy film
Flake 2
chequerboard
from both plateaus and trenches on the
(small
substrate.
connections)
EP154/18/2 -
5 μm × 50 μm
Efficient release of Permalloy film,
motif raised
chequerboard
but releases more readily from raised
(small gaps)
than lowered plateaus
Released particles exhibit excellent mono-
modal size distribution - see FIG. 12b.
[0127] The results of the release study were very encouraging. The 5 μm×50 μm chequerboard designs (motif raised) exhibited an excellent mono-modal size distribution, as shown in the two optical micrographs of FIG. 12 b.
[0128] It will be noted that the continuous rib flakes exhibited some curling along their length. These were generated perpendicular to the web and some were of considerable length. This was consistent with other observations where untextured substrate at the sides of the web generated randomly shaped flakes which also exhibited curling due to stress effects in the (stretched) continuous film. It would appear that discrete flakes of a limited length (not more than 100 microns) also have the advantage that their discrete nature allows the material to “relax”, which means they are surprisingly flat upon release.
Example 3
[0129] In this Example, methods of improving the wetting of the substrate were investigated.
[0000] (i) Corona discharge treatment: —A release agent coating formulation comprising: 2900 gm Deionised water, 89.4 gm Laponite RD and 100 gm of a surfactant Synperonic 91/6 (20%) was sprayed using a spray gun onto an embossed substrate comprising a sheet of 125 micron Melinex ST 505, half of which was corona treated and half left as made. This coating gave perfect wetting to the corona treated half of the embossed pattern, but on the non-corona treated half of the embossed structure, many retraction spots were observed indicating poor wetting.
(ii) Corona discharge/surfactant treatment: —A small scale study was carried out to investigate the efficacy of corona discharge treatment for improving the wettability of the embossed substrate to the release agent solution. Foaming of the release agent solution during application, thought to be due to the surfactant additive used to aid wetting, has been previously found to limit the throughput speed of the web—which would increase production costs. An alternative way of achieving this wetting is to corona discharge the embossed web which alters the surface chemistry to hydrophilic.
[0130] Flat embossed substrates with the 5 μm×50 μm chequerboard pattern were used for this study, the underlying substrate being 125 μm PET. Corona discharge treatment was carried out prior to coating with one of two release agent formulations, one with a surfactant, and one without any surfactant. The corona discharge settings varied from 5 m/min, 15 m/min to the fastest setting 25 m/min, which gave a minimal treatment.
[0131] The release agent coatings were applied to the substrates using 6 μm, 12 μm, 24 μm and 36 μm Meyer bars with the bar hand drawn in a direction parallel to the long axis of the embossed pattern. Coated sheets were dried on a flat glass sheet in an oven at 120° C. Details of the coated substrates, and brief qualitative notes on the quality of coating achieved, are given in Table 3.
[0000]
TABLE 3
Test embossed substrates, shaded rows indicate samples
overcoated with 1 μm of Permalloy for stripping trials.
Ragent
Drying time
Corona
Sample
Coating
at 120° C.
setting
number
Surfactant
(wet, μm)
(min)
(m/min)
Notes
EP154/39/1
✓
6
2
none
Poor coverage so conducted a second pass
EP154/39/2
✓
6
2
none
Slower Meyer bar speed, better coverage
EP154/39/3
✓
12
2
none
Good coverage
EP154/39/4*
✓
12
2
none
Good coverage - used as control sample
EP154/39/5
✓
24
2
none
Poor coverage, requires flooded Meyer bar
EP154/39/6
✓
24
3
none
Suspect coverage
EP154/39/7
✓
36
3
none
Poor coverage - coating too thick to control
EP154/39/8
✓
12
2
none
Poor coverage
EP154/39/9
✓
12
2
none
Poor coverage
EP154/39/10
✓
12
2
none
Poor coverage
EP154/39/11*
✓
12
2
5
Good coverage
EP154/39/12
x
12
2
5
Good coverage
EP154/39/13*
x
12
2
5
Good coverage
EP154/39/14
x
12
2
15
Good coverage
EP154/39/15
✓
12
2
15
Good coverage
EP154/39/16*
x
12
2
15
Good coverage
EP154/39/17
✓
12
2
None
Poor coverage
EP154/39/18
✓
12
2
25
Good coverage
EP154/39/19*
✓
12
2
25
Good coverage
EP154/39/20
x
12
2
25
Very poor coverage
[0132] It can be seen that use of corona discharge treatment (on all but the fastest setting of 25 m/min c.f. EP154/39/20) results in excellent wetting of the surfactant-free release agent onto the embossed substrate. Corona discharge treatment of the substrate is therefore a valid alternative to the inclusion of surfactant in the release agent solution, with equally effective particle release observed.
[0133] The shaded areas* in Table 3 denote samples with good wetting by the release agent coating and these were subsequently overcoated with ˜1 μm of Permalloy.
[0134] SEM micrographs of Permalloy overcoated substrates are shown in FIG. 13 (EP154/39/4—release agent with surfactant only) and FIG. 14 (EP154/39/19—corona treated, release agent with surfactant). In both cases there is a clear separation between the plateaus, caused by loss of definition in the photolithography process, and (on the plateaus) a well defined overhang of the release agent and metal coating due to the edge bead formed when the release agent is dried. The Permalloy film is therefore delineated into individual metal flakes.
[0135] Particle release studies were carried out using the method of immersion of the coated substrates in water, after being passed around a small rod with ultrasonic agitation. The results are briefly summarised in Table 4:
[0000] TABLE 4 Summary of release trials on test substrates Release agent Corona Sample Surfac- coating setting number tant (wet, μm) (m/min) Notes EP154/39/4 ✓ 12 none Released quickly. Released particles very well sized. EP154/39/11 ✓ 12 5 Lost during deposition. EP154/39/13 x 12 5 Released quickly. Released particles very well sized. EP154/39/16 x 12 15 Released quickly. Released particles very well sized. EP154/39/19 ✓ 12 25 Released quickly. Released particles very well sized.
Single flake particles released well from the plateaus. FIGS. 15 a and 15 b are, respectively, optical micrographs of the released Permalloy particles from sample EP154/39/4 (surfactant treated) and sample EP154/39/13 (corona treated) clearly showing the monomodal distribution.
Example 4
[0136] In this example, other thin film materials were trialled. Flake particles were generated from two commercially available, soft magnetic alloy films, Atalante® CoFeSiMoB and Atalante® CoZrNb film.
[0137] The roll substrate was a 36 μm thick non-heat-stabilised PET film coated with a 10 μm coating of embossed uv-curable acrylic resin embossed to a 5 μm depth. Wettability was improved using a corona discharge treatment on the substrate, or by incorporating a surfactant in the release agent solution. In a separate run, a 12 μm wet coat of the laponite-based release agent solution was applied with a bead coater, which gave a 0.5 μm dried coating of release agent.
[0138] This trial was to be conducted on an industrial scale (e.g. using 100 m sections of web substrate) and substrate of a new embossed design was manufactured. For large area substrate production large embossing shims were needed to fabricate the embossing roller. This in turn led to a change in the embossing procedure which resulted in narrower width for the raised plateaus of ˜2.5-3 μm and wall angles of ˜15°. This may be seen in the FIG. 16 SEM micrographs of the ˜3 μm×50 μm chequerboard embossed web substrate. There was also a tendency for the formation of finger structure artefacts, as may be seen in those Figures.
[0000] (i) The Atalante® CoFeSiMoB film was coated in its standard thickness of 1 micron on the above substrate. The release agent included a surfactant for wetting and no other wetting treatment was used. FIG. 17 shows two SEM micrographs of the substrate coated with Atalante® CoFeSiMoB film. It can be seen that a well defined overhang has been achieved around the raised plateaus; the reduced particle width is also evident. Other thicknesses of film were also laid down (0.8, 0.9, 1.1, 1.2 microns) and the respective sections subjected to standard stripping. The results are summarised in Table 5 below. Optical microscope examination of the stripped product was used to assess the proportion of single particle release and block release.
[0000] TABLE 5 Summary of trial stripping results for Atalante ® CoFeSiMoB film Atalante CoFeSiMoB thickness Notes −20%, 0.8 μm Good single particle release and minimal block release. −10%, 0.9 μm Good single particle release and minimal block release. 0%, 1 μm Good single particle release and minimal block release. +10%, 1.1 μm Good single particle release and minimal block release. +20%, 1.2 μm Good single particle release but a high proportion of block release of sprue material from the trenches.
Generally, there was good single particle release and minimal block release. The thinnest film appeared to release more slowly, while the extra thickness of the 1.2 micron film appeared to engender the sprue with greater mechanical strength making it more likely to release and, having done so, not break up (with the agitation power of the bath used).
[0139] FIG. 18 is an optical micrograph of the released Atalante® CoFeSiMoB film particles illustrating the replication of the micron scale ‘finger’ features from the embossed substrate.
[0000] (ii) The Atalante® CoZrNb film was coated by a similar process on one substrate that had been corona discharge treated and another that had not, but that had included a surfactant in the release agent solution.
[0000] TABLE 6 Summary of trial stripping results for Atalante ® CoZrNb CZN thickness Notes Roll 1 (corona discharge treatment, no surfactant in release agent solution) +33%, 1 μm Optical microscope examination of the stripped product shows good proportion of single particles. Roll 3 (no corona discharge treatment, surfactant in release agent solution) +33%, 1 μm Optical microscope examination of the stripped product shows good single particle release and minimal block release.
The film was deposited to a thickness of 1 micron, which is 33% above its standard thickness and this allowed a good proportion of single particles to be released. FIG. 19 shows two SEM micrographs of the Atalante® CoZrNb and release agent (with surfactant) coated substrate. The detailed picture shows the definition of the deposited film into individual particles, on the plateau tops, via the overhang created by the edge beading of the dried release agent. As observed for the other Atalante® film, the substrate ‘finger’ structures have been replicated on the elongate particles, demonstrating that the particle formation technique is capable of replicating micron-scale features. Finally, referring to FIG. 20 , this shows two optical micrographs of the released Atalante® CoZrNb film particles, again illustrating the replication of the micron scale ‘finger’ features from the embossed substrate, as well as the mono-modal distribution.
Example 5
[0140] In this example, alternative release agents to Laponite RD were trialled, including water soluble and organic solvent based release agents. Alternative flake materials to magnetic alloys were also trialled, and an alternative technique used for depositing the flake material.
[0141] The substrate used was a flat bed (as opposed to roll-to-roll) embossed substrate of the grid design having a surface delineated into 5 μm wide×5 μm deep trenches and 50 μm×100 μm plateaus with a ˜17° trench side wall angle. This structure was embossed into a UV-cured acrylic resin coated onto 36 μm thick PET, as previously described and depicted in FIGS. 8 a and 8 b of Example 1.
[0142] Alternative release agents were trialled to see if they could be successfully applied to a textured substrate, and would enable the subsequent release of shaped particles.
[0143] They were initially assessed for their miscibility in either water or organic solvent (MEK), as appropriate, and their ability to form a thin film upon application to a polymer substrate. Table 7 gives a summary of the results for LG156 PMMA (MEK soluble), Sodium Tetraborate (“Borax”, water soluble), PVA (adhesive, water soluble) and polyacrylamide (water soluble), which all proved suitable: —
[0000]
TABLE 7
Summary of assessment of various release agent materials
Film
Solubility
Solubility
Wetting
forming
Material
in water
In MEK
treatment
ability
LG156 PMMA
Yes
No
Yes
Sodium
Yes
corona
Streaky
tetraborate
film
PVA
Yes
corona
Yes
Polyacrylamide
Yes
surfactant
Yes
[0144] Diakon™ LG156 PMMA (Poly (methyl methacrylate)), in particular, exhibited good solubility in MEK and good film forming ability and did not require a wetting treatment.
[0145] Release agent coated textured substrates were then fabricated using Laponite RD and selected materials from Table 7 as release agents.
[0146] The release agents were made up into either water or MEK solutions, applied as a ˜12 μm thick wet coat using a Meyer (or K) bar and subsequently dried in an oven at 90° C. for a few minutes to give a dry coat of ˜0.5-0.6 μm thickness. To aid the wetting of the release agent coating onto the embossed substrates, some substrates were either corona treated (using an atmospheric pressure corona discharge) or a surfactant was added to the release agent solution.
[0147] The following release agent coated substrates were prepared and are summarised in Table 8.
[0000]
TABLE 8
Summary of coated substrates
Sample ID
Release agent material
Wetting treatment
EP157/30/1
Laponite RD
surfactant
EP157/30/2
EP157/30/3
Laponite RD
corona
EP157/30/4
EP157/30/5
Borax
surfactant
EP157/30/6
corona
EP157/30/7
Polyacrylamide
surfactant
EP157/30/8
corona
EP157/30/9
PMMA (LG156)
none
[0148] The (dry) release agent coated substrates were subject to detailed SEM examination, with FIGS. 21 to 23 showing images of certain samples. To summarise: —
The Laponite RD coated substrates exhibited good apparent coverage of the plateau tops and (trench) bottoms, for both surfactant and corona variants, and also the development of the overhang feature thought to be important in the release process. FIGS. 21 a and b respectively show SEM images of Borax coated embossed substrates with wetting treatments of (a) surfactant and (b) corona. The surfactant variant of the Borax coated substrate exhibited undesirable retraction of the release agent coating from the plateau edge whilst the corona variant looks to have coated both the plateaus well, with possible evidence of an overhang feature. The level of coating in the trenches appears to be variable with no or minimal side-wall coating at the embossed feature corners and steadily increasing (though not completely to the plateau tops) side wall coating away from the corners. FIGS. 22 a and b respectively show SEM images of Polyacrylamide coated embossed substrates with wetting treatments of (a) surfactant and (b) corona. The polyacrylamide coated samples exhibit good coverage of the plateau tops, with apparent overhang, for both variants. Partial retraction of the release agent coating from the trench floors, at the intersections, is observed for the surfactant variant, with the degree of side wall coating appearing to increase away from the intersections. For the corona variant no release agent retraction was observed. FIG. 23 shows SEM images of PMMA (LG156) coated embossed substrate. The PMMA coated sample appears to have coated very well with excellent apparent coverage of the plateau's, with apparent overhang, and trench floors. From the SEM pictures it is not clear to what extent, if any, the side walls have been coated.
[0153] After release agent coating, the substrates were then overcoated with a metal layer via physical vapour deposition techniques, namely either thermal evaporation or sputtering. In the machine configurations used, the thermal evaporation process is essentially a room temperature process while the sputtering process is somewhat above room temperature—the latter possibly having affected the performance of some of the release agent materials.
[0154] The substrates were coated with thermally evaporated aluminium, with sputtered permalloy (Ni 0.8 Fe 0.2 ), and with a sputtered non-magnetic AgAu alloy (Ag 0.85 Au 0.15 ), the first being a pigment industry standard material/method.
[0155] To assess the efficacy of the potential release agent materials, the overcoated samples were then subjected to stripping. For this a ˜1″×1″ piece was cut out, passed around a narrow rod and then placed in ultrasonically agitated (Ultrawave U50 ultrasonic bath) release solution—either water or MEK (Methyl Ethyl Ketone, or butanone), depending on the material. If stripping was successful, then released particles were collected in a Pasteur pipette and deposited on filter paper for detailed examination using an optical microscope.
[0156] Results of the release trials are summarised in Tables 9 to 12 with optical micrographs of a selection of the released particles shown in FIGS. 24 to 26 , as identified in the right hand column.
[0000]
TABLE 9
Summary of release studies using Laponite RD
Shaped
Release Agent +
Stripping
particles
Sample ID
wetting treatment
Overcoat
medium
generated
Comments
EP157/30/1
Laponite RD +
Evaporated
water
✓
Release of shaped
Quadrant B
surfactant
Al
particles but tend to
~240 nm
be damaged - film
too thin for area?
EP157/30/1
Sputtered
water
✓
Efficient and quick
Quadrant C
Permalloy
release of shaped
~1 μm
particles & sprues.
EP157/30/1
Sputtered
water
✓
Quick and efficient
Quadrant A
AgAu
release of shaped
~1 μm
particles & sprues,
small proportion of
breakages.
EP157/30/3
Laponite RD +
Evaporated
water
✓
Efficient and quick
Quadrant B
corona
Al
release of shaped
~550 nm
particles & sprues.
EP157/30/3
Sputtered
water
✓
Slow and inefficient
Quadrant A
AgAu
release, but nicely
~1 μm
shaped intact
particles.
[0000]
TABLE 10
Summary of release studies using Borax
Shaped
Release Agent +
Stripping
particles
Sample ID
wetting treatment
Overcoat
medium
generated
Comments
EP157/30/6
Borax +
Evaporated
water
✓
Efficient and
Octant B2
corona
Al
quick release of
~550 nm
shaped particles
& sprues.
FIG. 24a
EP157/30/6
Sputtered
water
✓
Efficient and
Quadrant C
Permalloy
quick release of
~1 μm
shaped particles
& sprues; high
proportion of
broken particles.
FIG. 24b
EP157/30/6
Sputtered
water
✓
Efficient and
Quadrant A
AgAu
quick release of
~1 μm
shaped particles
& sprues.
[0000]
TABLE 11
Summary of release studies using Polyacrylamide
Shaped
Release Agent +
Stripping
particles
Sample ID
wetting treatment
Overcoat
medium
generated
Comments
EP157/30/7
Polyacrylamide +
Evaporated
water
✓
Reasonable release
Quadrant B
surfactant
Al
of shaped particles
~240 nm
but tendency for
breakage; released
sprues intact &
regular.
Evaporated
water
✓
Reasonable release
Al
of shaped particles
~240 nm
but tendency for
breakage; released
sprues intact &
regular.
Evaporated
water
✓
Reasonable release
Al (2 coats)
of shaped particles,
~500 nm
reduced breakage c.f.
240 nm; released
sprues intact &
regular.
FIG. 25a
EP157/30/7
Sputtered
water
✓
Reasonable release
Quadrant C
Permalloy
of shaped particles
~1 μm
and sprues.
FIG. 25b
EP157/30/7
Sputtered
water
x
No significant release,
Quadrant A
AgAu
probably due to heat
~1 μm
damage during
deposition.
EP157/30/8
Polyacrylamide +
Evaporated
water
✓
Good efficient release
Quadrant B
corona
Al (1 coat)
of shaped particles
~500 nm
and some sprue
material.
EP157/30/8
Sputtered
water
✓
Slow to release but
Quadrant A
AgAu
excellent release of
~1 μm
intact, and very bright
particles.
[0000]
TABLE 12
Summary of release studies using PMMA
Shaped
Release Agent +
Stripping
particles
Sample ID
wetting treatment
Overcoat
medium
generated
Comments
EP157/30/9
LG156 PMMA
Evaporated
MEK
✓
Very quick and
Octant B2
Al (1 coat)
efficient release of
~507 nm
shaped particles
and sprues.
FIG. 26a
EP157/30/9
Sputtered
MEK
✓
Very quick and
Quadrant C
Permalloy
efficient release of
~1 μm
shaped particles
and sprues. High
proportion of
broken particles.
FIG. 26b
EP157/30/9
Sputtered
MEK
✓
Very quick and
Quadrant A
AgAu
efficient release of
~1 μm
shaped particles
with good flatness
and surface
morphology.
Notes:
Sprues denote material release from the interstitial trenches.
[0157] The results were encouraging and showed that, even in this basic trial (where the stripping process had not been refined for any particular release agent system/flake material combination), the release agent systems selected were capable of providing flake particles of a selected size and shape.
[0158] This short study showed that a variety of water/organic solvent compatible materials may be used as release agents which enable the release of metallic flakes of controlled size and shape from an embossed substrate. These alternative materials are borax (sodium tetraborate, water soluble), polyacrylamide (water soluble) and PMMA (organic solvent soluble). The choice of most appropriate wetting treatment appears to depend on the particular release agent/embossed substrate system. Metallic flakes of both thermally evaporated aluminium (a pigment industry standard material/method) and sputtered alloys (magnetic and non-magnetic) were realised using the alternative release agent materials. In addition shaped particles of all 3 different flake materials were generated using the Laponite RD release agent with both the surfactant and corona discharge wetting treatments.
[0159] It will be appreciated that the embodiments described above illustrate the invention but are not to be regarded as restricting the invention. Other modifications or variations of the process or textured substrate will be apparent to the skilled person but will still be in accordance with the present invention. In particular, although the use of a clay mineral release layer or a PMMA release layer is highly preferred, other suitable release agents may also be used, particularly where, for example, the release is otherwise assisted, for example, by use of an adhesive transfer layer that removes the particles mechanically. Depending on the type of material being deposited as a thin film, a textured substrate with a coating of release agent or an inbuilt release layer, or indeed, a textured substrate with inherent releasability may be used.
[0160] Other particle shapes and sizes may also be selected in accordance with the present invention to those described above; particularly where the flakes are intended for applications other than pigments or paints.
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The invention enables thin film particles of a controlled shape and size to be generated directly upon release of a thin film coating from a textured Substrate upon which they are grown directly. The substrate comprises an array of discrete, steep sided plateaus of a selected size and shape, from which discrete particles of a corresponding shape and size are releasable usually by means of an intermediate release layer coating on the plateaus. The process is readily scalable for high volume production and permits monomodal or multimodal particle size distributions. Such particles may be used as specialised pigments in the security, anti-counterfeiting, defence and cosmetics industries.
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FIELD OF THE INVENTION
[0001] This invention relates generally to the distribution of entertainment media to a viewer on-demand.
BACKGROUND OF THE INVENTION
[0002] Cable and satellite television service providers often offer specific television programs to viewers on a pay-per-view basis. The service provider fixes a price for a particular program based upon previous demand for similar programs and the cost of the program (either copyright fees or production costs) and then offers the program to viewers. If the price is too high, too few viewers will request the program, if the cost is too low, the total revenue generated will be less than optimal.
SUMMARY OF THE INVENTION
[0003] Accordingly, certain embodiments of the current invention provide a method by which a cable or satellite television service provider may obtain information as to the likely revenues that will be generated by a specific program offering prior to actually offering the program.
[0004] According to an embodiment of the present invention, an information network, such as an interactive set-top box, is provided to a subscriber. Through interaction with the set-top box, a subscriber may indicate his or her interest in a specific program offering and the price he or she would be willing to pay for it. This information is communicated to the service provider over a communications link, such as the Internet.
[0005] With this embodiment of the present invention, the service provider collects information regarding the acceptable pricing for the program. In the preferred embodiment, this information is gathered through the subscriber's navigation and interaction with web pages served by the service provider to the subscriber.
[0006] The service provider may poll subscribers, asking a subscriber to bid on a particular program and to commit to purchasing that program if it is subsequently made available at a price equal to or less than the bid.
[0007] The service provider may operate a web site, in which an inventory of programs, such as movies or forthcoming events, is categorized and listed (with descriptions, reviews etc.). The web site may be arranged so that a subscriber can register his or her level of interest in a particular program and the price he or she would be willing to pay. The subscriber may also request other programs not listed.
[0008] The service provider determines which programs to offer based upon the level of interest, the cost of the program, available bandwidth for delivery and other factors.
[0009] Accordingly, the service provider may optimize the efficiency of program delivery, which results in a combination of higher profits for the operator and lower prices for the subscriber.
[0010] The above summaries are intended to illustrate exemplary embodiments of the invention, which will be best understood in conjunction with the detailed description to follow, and are not intended to limit the scope of the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The novel features believed characteristic of the invention are set forth in the claims. The invention itself, however, as well as the preferred mode of use, and further objects 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 drawing(s), wherein:
[0012] [0012]FIG. 1 shows an exemplary plot of the relationship between the price of a program and the number of subscribers who will purchase the program. It also shows the resulting relationship between the revenue generated and the price.
[0013] [0013]FIG. 2 is a block diagram of an exemplary interactive television (TV) system, in accordance with the present invention.
[0014] [0014]FIG. 3 shows a system configuration for an exemplary digital set-top box, in accordance with an embodiment of the present invention.
[0015] [0015]FIG. 4 illustrates an exemplary method for program price establishment, in accordance with the present invention.
DESCRIPTION OF THE INVENTION
[0016] While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail one or more specific embodiments, with the understanding that the present disclosure is to be considered as exemplary of the principles of the invention and not intended to limit the invention to the specific embodiments shown and described. In the description below, like reference numerals are used to describe the same, similar or corresponding parts in the several Views of the drawings.
[0017] [0017]FIG. 1 shows an exemplary plot of the relationship between the price of a program and the number of subscribers who will purchase the program. It also shows the resulting relationship between the revenue generated and the price. The upper plot in FIG. 1 depicts an exemplary relationship between the price charged to the subscriber for a particular program and the number of subscribers who will purchase the program at that price or at a lower price. When the price is low, less than $2, for example, a high number of subscribers (90,000 in this example) will purchase the program. As the price increases, fewer and fewer subscribers will purchase the program. Above $10, no subscribers will purchase the program. The revenue generated by the program is determined by the number of subscribers purchasing the program multiplied by the price charged for the program. The relationship between the revenue generated and the price charged is depicted in the lower plot of FIG. 1. In this example, the maximum revenue generated will be $315,000 and will occur when the program is offered at a price of $4.60.
[0018] This knowledge enables the service provider to compare this particular program with other programs and determine which program will provide the highest net return.
[0019] If the program contains advertising, it is likely that the revenue received from advertisers is related to the number of subscribers purchasing the program. This revenue, and the cost of the program, may also be considered when determining the net income resulting from delivery of the program.
[0020] Referring now to FIG. 2, a block diagram for an exemplary interactive cable or satellite television (TV) system 100 is shown. The system 100 includes, at a head end of the service provider 10 , a media server 12 for providing, on demand, movies and other programming obtained from a media database 14 . The media server 12 might also provide additional content such as broadcast sporting events, interviews with the actors, games, advertisements, available merchandise, associated Web pages, interactive games and other related content. The system 100 also includes an information server 16 and a program listing database 18 . The program listing database 18 may contain a list of scheduled broadcast programs, programs available on-demand and programs that could be made available on demand if there was sufficient interest from subscribers. The system 100 also includes a subscriber information database 19 , in which is stored the reported subscriber interest in currently offered and on-demand programs that may be offered in the future. The subscriber information database 19 is linked or related to the program listing database 18 . In one embodiment, the information in the subscriber information database 19 is gathered through the subscriber's navigation and interaction with web pages served by the service provider to the subscriber. These web pages may be served from the information server 16 , or from ISP Host 38 . The subscriber may access the web pages at any time, or may be prompted, by the service provider, to respond to a questionnaire. For each program, the information may include the subscriber's interest level (low, medium, high for example), the price a subscriber might pay, the likelihood of purchase on a particular day or at a particular time. The system 100 also includes a processing unit 21 , which is configured to use the information in the subscriber information database 19 to calculate a preferred offer price for programs offered to the subscriber for purchase. The processing unit 21 may use additional information such as program costs, likely advertising revenue and promotional value, to determine the preferred offer price. The processing unit 21 may also be configured to determine which programs are offered to the subscriber for purchase.
[0021] Set-top box 22 can generally provide for bidirectional communication over a transmission medium 20 in the case of a cable STB 22 . In other embodiments, bidirectional communication can be effected using asymmetrical communication techniques possibly using dual communication media—one for the uplink and one for the downlink. In any event, the STB 22 can have its own Universal Resource Locator (URL) or IP address or other unique identifier assigned thereto to provide for addressability by the head end and users of the Internet.
[0022] The media server 12 and information server 16 are operatively coupled by transmission medium 20 to a set-top box (STB) 22 . The transmission medium 20 may include, for example, a conventional coaxial cable network, a fiber optic cable network, telephone system, twisted pair, a satellite communication system, a radio frequency (RF) system, a microwave system, other wireless systems, a combination of wired and wireless systems or any of a variety of known electronic transmission mediums. In the case of a cable television network, transmission medium 20 is commonly realized at the subscriber's premises as a coaxial cable that is connected to a suitable cable connector at the rear panel of the STB 22 . In the case of a Direct Satellite System (DSS), the STB 22 is often referred to as an Integrated Receiver Decoder (IRD). In the case of a DSS system, the transmission medium is a satellite transmission at an appropriate microwave band. Such transmissions are typically received by a satellite dish antenna with an integral Low Noise Block (LNB) that serves as a down-converter to convert the signal to a lower frequency for processing by the STB 22 .
[0023] The exemplary system 100 further includes a TV 24 , such as a digital television, having a display 26 for displaying programming, web pages, etc. The STB 22 may be coupled to the TV 24 and various other audio/visual devices 27 (such as audio systems, Personal Video Recorders (PVRs), Video Tape Recorders (VTRs), Video Cassette Recorders (VCRs) and the like), storage devices (e.g., hard disc drives) and Internet Appliances 28 (such as email devices, home appliances, storage devices, network devices, and other Internet Enabled Appliances) by an appropriate interface 30 , which can be any suitable analog or digital interface. In one embodiment, interface 30 conforms to an interface standard such as the Institute of Electrical and Electronics Engineers (IEEE) 1394 standard, but could also be wholly or partially supported by a DVI interface (Digital Visual Interface—Digital Display Working Group, www.ddwg.org) or other suitable interface.
[0024] The STB 22 may include a central processing unit (CPU) such as a microprocessor and memory such as Random Access Memory (RAM), Read Only Memory (ROM), flash memory, mass storage such as a hard disc drive, floppy disc drive, optical disc drive or may accommodate other electronic storage media, etc. Such memory and storage media is suitable for storing data as well as instructions for programmed processes for execution on the CPU, as will be discussed later. Information and programs stored on the electronic storage media or memory may also be transported over any suitable transmission medium such as that illustrated as 20 . STB 22 may include circuitry suitable for audio decoding and processing, the decoding of video data compressed in accordance with a compression standard such as the Motion Pictures Experts Group (MPEG) standard and other processing to form a controller or central hub. Alternatively, components of the STB 22 may be incorporated into the TV 24 itself, thus eliminating the STB 22 . Further, a computer having a tuner device and modem may be equivalently substituted for the TV 24 and STB 22 .
[0025] By way of example, the STB 22 may be coupled to devices such as a personal computer, video cassette recorder, camcorder, digital camera, personal digital assistant and other audio/visual or Internet related devices. In addition, a data transport architecture may be utilized to enable interoperability among devices on a network regardless of the manufacturer of the device if the manufacturers agree to adhere to an industry standard. The STB 22 runs an operating system suitable for a home network system.
[0026] The STB 22 includes an infrared (IR) receiver 34 for receiving IR signals from an input device such as remote control 36 . Alternatively, it is noted that many other control communication methods may be utilized besides IR, such as wired or wireless radio frequency, etc. In addition, it can be readily appreciated that the input device 36 may be any device suitable for controlling the STB 22 such as a remote control, personal digital assistant, laptop computer, keyboard or computer mouse. In addition, an input device in the form of a control panel located on the TV 24 or the STB 22 can be provided.
[0027] The STB 22 may also be coupled to an independent service provider (ISP) host 38 by a suitable connection including dial-up connections, DSL (Digital Subscriber Line) or the same transmission medium 20 described above (e.g., using a cable modem) to, thus, provide access to services and content from the ISP and the Internet. The ISP host 38 provides various content to the user that is obtained from a content database 52 . STB 22 may also be used as an Internet access device to obtain information and content from remote servers such as remote server 48 via the Internet 44 using host 38 operating as an Internet portal, for example. In certain satellite STB environments, the data can be downloaded at very high speed from a satellite link, with asymmetrical upload speed from the set-top box provided via a dial-up or DSL connection.
[0028] While the arrangement illustrated in FIG. 2 shows a plurality of servers and databases depicted as independent devices, any one or more of the servers can operate as server software residing on a single computer. Moreover, although not explicitly illustrated, the servers may operate in a coordinated manner under centralized or distributed control to provide multiple services as a Multiple Service Operator (MSO) in a known manner. Additionally, the services provided by the servers shown in FIG. 2 may actually reside in other locations, but from the perspective of the user of STB 22 , the service provider 10 serves as a portal to the services shown. Those skilled in the art will appreciate that the illustration of FIG. 2 represents a simplified depiction of a cable system configuration shown simply as service provider 10 . The actual configuration of the service provider's equipment is more likely to follow a configuration defined by the CableLabs OpenCable™ specification. The simplified illustration shown is intended to simplify the discussion of the service provider 10 's operation without unnecessarily burdening the discussion with architectural details that will be evident to those skilled in the art. Many of those details can be found in the publicly available CableLabs OpenCable™ specification or in the text “OpenCable Architecture (Fundamentals)” by Michael Adams, Cisco Press, November 1999.
[0029] Referring now to FIG. 3, a typical system configuration for a digital set-top box 22 is illustrated. In this exemplary set-top box, the transmission medium 20 , such as a coaxial cable, is coupled by a suitable interface through a diplexer 102 to a tuner 104 . Tuner 104 may, for example, include a broadcast in-band tuner for receiving content, an out-of-band (OOB) tuner for receiving data transmissions. A return path through diplexer 102 provides an OOB return path for outbound data (destined for example for the head end). A separate tuner (not shown) may be provided to receive conventional RF broadcast television channels. Modulated information formatted, for example, as MPEG-2 information is then demodulated at a demodulator 106 . The demodulated information at the output of demodulator 106 is provided to a demultiplexer and descrambler circuit 110 where the information is separated into discrete channels of programming. The programming is divided into packets, each packet bearing an identifier called a Packet ID (PID) that identifies the packet as containing a particular type of data (e.g., audio, video, data). The demodulator and descrambler circuit 110 also descrambles scrambles information in accordance with a decryption algorithm to prevent unauthorized access to programming content, for example.
[0030] Audio packets from the demultiplexer 110 (those identified with an audio PID) are decrypted and forwarded to an audio decoder 114 where they may be converted to analog audio to drive a speaker system (e.g., stereo or home theater multiple channel audio systems) or other audio system 116 (e.g., stereo or home theater multiple channel amplifier and speaker systems) or may simply provide decoded audio out at 118 . Video packets from the demultiplexer 110 (those identified with a video PID) are decrypted and forwarded to a video decoder 122 . In a similar manner, data packets from the demultiplexer 110 (those identified with a data PID) are decrypted and forwarded to a data decoder 126 .
[0031] Decoded data packets from data decoder 126 are sent to the set-top box's computer system via the system bus 130 . A central processing unit (CPU) 132 can thus access the decoded data from data decoder 126 via the system bus 130 . Video data decoded by video decoder 122 is passed to a graphics processor 136 , which is a computer optimized to processes graphics information rapidly. Graphics processor 136 is particularly useful in processing graphics intensive data associated with Internet browsing, gaming and multimedia applications. It should be noted, however, that the function of graphics processor 136 may be unnecessary in some set-top box designs having lower capabilities, and the function of the graphics processor 136 may be handled by the CPU 132 in some applications where the decoded video is passed directly from the demultiplexer 110 to a video encoder. Graphics processor 136 is also coupled to the system bus 130 and operates under the control of CPU 132 .
[0032] Many set-top boxes such as STB 22 may incorporate a smart card reader 140 for communicating with a so called “smart card,” often serving as a Conditional Access Module (CAM). The CAM typically includes a central processor unit (CPU) of its own along with associated RAM and ROM memory. Smart card reader 140 is used to couple the system bus of STB 22 to the smart card serving as a CAM (not shown). Such smart card based CAMs are conventionally utilized for authentication of the user and authentication of transactions carried out by the user as well as authorization of services and storage of authorized cryptography keys. For example, the CAM can be used to provide the key for decoding incoming cryptographic data for content that the CAM determines the user is authorized to receive.
[0033] STB 22 can operate in a bidirectional communication mode so that data and other information can be transmitted not only from the system's head end to the end user, or from a service provider to the end user of the STB 22 , but also, from the end user upstream using an out-of-band channel. In one embodiment, such data passes through the system bus 130 to a modulator 144 through the diplexer 102 and out through the transmission medium 20 . This capability is used to provide a mechanism for the STB 22 and/or its user to send information to the head end (e.g., service requests or changes, registration information, etc.) as well as to provide fast outbound communication with the Internet or other services provided at the head end to the end user.
[0034] Set-top box 22 may include any of a plurality of I/O (Input/Output) interfaces represented by I/O interfaces 146 that permit interconnection of I/O devices to the set-top box 22 . By way of example, and not limitation, a serial RS- 232 port 150 can be provided to enable interconnection to any suitable serial device supported by the STB 22 's internal software. Similarly, communication with appropriately compatible devices can be provided via an Ethernet port 152 , a USB (Universal Serial Bus) port 154 , an IEEE 1394 (so-called firewire™ or i-LINK™) or IEEE 1394 port 156 , S-video port 158 or infrared port 160 . Such interfaces can be utilized to interconnect the STB 22 with any of a variety of accessory devices such as storage devices, audio/visual devices 26 , gaming devices (not shown), Internet Appliances 28 , etc.
[0035] I/O interfaces 146 can include a modem (be it dial-up, cable, DSL or other technology modem) having a modem port 162 to facilitate high speed or alternative access to the Internet or other data communication functions. In one preferred embodiment, modem port 162 is that of a DOCSIS (Data Over Cable System Interface Specification) cable modem to facilitate high-speed network access over a cable system, and port 162 is appropriately coupled to the transmission medium 20 embodied as a coaxial cable. Thus, the STB 22 can carry out bidirectional communication via the DOCSIS cable modem with the STB 22 being identified by a unique IP address. The DOCSIS specification is publicly available. Of course it is envisioned that the modem can be built into the set-top box.
[0036] A PS/ 2 or other keyboard/mouse/joystick interface such as 164 can be provided to permit ease of data entry to the STB 22 . Such inputs provide the user with the ability to easily enter data and/or navigate using pointing devices. Pointing devices such as a mouse or joystick may be used in gaming applications.
[0037] Of course, STB 22 also may incorporate basic video outputs 166 that can be used for direct connection to a television set such as 24 instead of (or in addition to) an IEEE 1394 connection such as that illustrated as 30 . In one embodiment, Video output 166 can provide composite video formatted as NTSC (National Television System Committee) video. The infrared port 160 can be embodied as an infrared receiver 34 as illustrated in FIG. 2, to receive commands from an infrared remote control 36 , infrared keyboard or other infrared control device. Although not explicitly shown, front panel controls may be used in some embodiments to directly control the operation of the STB 22 through a front panel control interface as one of interfaces 146 . Selected interfaces such as those described above and others can be provided in STB 22 in various combinations as required or desired.
[0038] STB 22 will more commonly, as time goes on, include a disc drive interface 170 and disc drive mass storage 172 for user storage of content and data as well as providing storage of programs operating on CPU 132 . STB 22 may also include floppy disc drives, CD ROM drives, CD RAW drives, DVD drives, etc. CPU 132 , in order to operate as a computer, is coupled through the system bus 130 (or through a multiple bus architecture) to memory 176 . Memory 178 may include a combination any suitable memory technology including Random Access Memory (RAM), Read Only Memory (ROM), Flash memory, Electrically Erasable Programmable Read Only Memory (EEPROM), etc.
[0039] While the above exemplary system including STB 22 is illustrative of the basic components of a digital set-top box suitable for use with the present invention, the architecture shown should not be considered limiting since many variations of the hardware configuration are possible without departing from the present invention. The present invention could, for example, also be implemented in more advanced architectures such as that disclosed in U.S. patent application Ser. No. 09/473,625, filed Dec. 29, 1999, Docket No. SONY-50N3508 entitled “Improved Internet Set-Top Box Having and In-Band Tuner and Cable Modem” to Jun Maruo and Atsushi Kagami. This application describes a set-top box using a multiple bus architecture with a high level of encryption between components for added security, and a separate video path. This application is hereby incorporated by reference as though disclosed fully herein.
[0040] In general, during operation of the STB 22 , an appropriate operating system 180 such as, for example, Sony Corporation's Aperios™ real time operating system is loaded into, or is permanently stored in, active memory along with the appropriate drivers for communication with the various interfaces. In other embodiments, other operating systems such as Microsoft Corporation's Windows CE™ could be used without departing from the present invention. Along with the operating system and associated drivers, the STB 22 usually operates using browser software 182 in active memory or browser software may permanently reside in ROM, EEPROM or Flash memory, for example. The browser software 182 may operate as the mechanism for viewing not only web pages on the Internet, and can serve as the mechanism for viewing an Electronic Program Guide (EPG) formatted as an HTML document. The browser 182 can be used to view and fill out HTML questionnaires regarding the subscriber's interest in programs that may be offered on-demand in the future. This information is collected by the service provider and stored in the subscriber information database, described above.
[0041] STB software architectures vary depending upon the operating system. However, in general, all such architectures generally include, at the lowest layer, various hardware interface layers. Next is an operating system layer as previously described. The software architectures of modern STB have generally evolved to include a next layer referred to as “middleware.” Such middleware permits applications to run on multiple platforms with little regard for the actual operating system in place. Middleware standards are still evolving at this writing, but are commonly based upon Javascript and HTML (hypertext Markup Language) virtual machines. At the top layer is the application layer where user applications and the like reside, e.g., browsing, email, EPG, Video On Demand (VOD), rich multimedia applications, pay per view, etc. The current invention can be utilized with any suitable set-top box software and hardware architecture.
[0042] In one embodiment, the service provider calculates the value of movie as follows. FIG. 4 shows an exemplary mode of operation 200 of the present invention. Subscriber information 204 is collected from subscribers and stored in the subscriber information database 208 . The expected number of purchasers, N, is calculated at block 210 as a function of the price p ( 202 ) charged to the subscribers. The expected number of purchasers is depicted as 212 . The direct revenue generated, R d (depicted as 216 ), is obtained by multiplying the product of the price charged 202 and the number of purchasers 212 at multiplier 214 . The resultant Direct Revenue Generated 216 is
R d =p×N ( p )
[0043] The optimal direct price p max ( 219 ), which maximizes the direct revenue, is calculated at calculation block 218 . The advertising revenue, R a ( 229 ) is calculated at calculation block 228 and is a function of the number of purchasers, N ( 212 ), since generally advertisers will pay more to advertise in during programs with a larger audience. The function dependence of R a upon the number of purchasers may be determined from historical data or by polling potential advertisers. The program also has a promotional value, R p ( 225 ), which is calculated at calculation block 224 . For example, if a recent popular movie is offered at a price perceived to be low, advertisement of the offer may attract more subscribers. The promotion value, R p , can be considered as a function of the difference 222 between the offered price p ( 202 ) and the optimal direct price p max ( 219 ). The difference 222 is calculated at subtractor 220 . The functional dependence of R a may be determined with reference to historical data. The value, V(p) ( 234 ), of the movie to the service provider may then be calculated as the sum of signals 216 , 225 and 229 less the cost of the program 206 . This gives
V ( p ) = R d + R a + R p - C = p × N ( p ) + R a ( N ( p ) ) + R p ( p max - p ) - C ,
[0044] where C is the cost of the movie. This is calculated using summers 226 and 230 and subtractor 232 . Since the function N(p) is known from information in the subscriber information database, the preferred offer price 238 for the movie may be determined by maximizing the value V(p) ( 234 ) with respect to the price p ( 202 ) at calculation block 236 . This calculation may be performed for each movie in turn, thereby providing the service provider with a method for deciding which movie(s) to broadcast.
[0045] The above discussion is simplified, of course, and other factors, such as the time and date of the broadcast, may need to be considered also. Also, the interaction between movies may need to be considered. This is the case, for example, when multiple movies are broadcast simultaneously, or when subscribers have a limited budget for purchasing movies.
[0046] Those skilled in the art will recognize that the present invention has been described in terms of exemplary embodiments based upon use of a programmed processor. However, the invention should not be so limited, since the present invention could be implemented using hardware component equivalents such as special purpose hardware and/or dedicated processors which are equivalents to the invention as described and claimed. Similarly, general purpose computers, microprocessor based computers, micro-controllers, optical computers, analog computers, dedicated processors and/or dedicated hard wired logic may be used to construct alternative equivalent embodiments of the present invention.
[0047] Those skilled in the art will appreciate that the program steps used to implement the embodiments described above can be implemented using disc storage as well as other forms of storage including Read Only Memory (ROM) devices, Random Access Memory (RAM) devices; optical storage elements, magnetic storage elements, magneto-optical storage elements, flash memory, core memory and/or other equivalent storage technologies without departing from the present invention. Such alternative storage devices should be considered equivalents.
[0048] The present invention is preferably implemented using a programmed processor executing programming instructions that are broadly described above in flow chart form and can be stored in any suitable electronic storage medium. However, those skilled in the art will appreciate that the processes described above can be implemented in any number of variations and in many suitable programming languages without departing from the present invention. For example, the order of certain operations carried out can often be varied, and additional operations can be added without departing from the invention. Error trapping can be added and/or enhanced and variations can be made in user interface and information presentation without departing from the present invention. Such variations are contemplated and considered equivalent.
[0049] While the invention has been described in conjunction with specific embodiments, it is evident that many alternatives, modifications, permutations and variations will become apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended that the present invention embrace all such alternatives, modifications and variations as fall within the scope of the appended claims.
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An information network, such as an interactive set-top box, is provided to a subscriber. Through interaction with the set-top box, a subscriber may indicate his or her interest in a specific television or video program to be offered by a service provider and the price he or she would be willing to pay for it. This information is communicated to the service provider over a communications link, such as the Internet. The service provider uses the information to determine the offer price of the television or video program.
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BACKGROUND OF THE INVENTION
A shower head functions to let out water through a plurality of small holes on a human body in bathing. Bathing is an indispensable daily routine not only for cleaning a human body but for healing fatigue to recover bodily fittness. Though there are not a few bathing appliances such as sauna, massage bathtubs, they are too costly for common people.
SUMMARY OF THE INVENTION
This invention has aimed to have the following features.
1. It has functions to supply water and soap solution, to give rise to bubbles, to clean, scrub or massage a human body with extra units adapted to be additionally attached on the shower head.
2. It has an extra electric heating case, which provides hot vapor or heated air, stores soap solution and a motor therein to rotate a wire rope.
3. It comprises an electric time circuit for supplying water and an electric time circuit for turning on and off a heater.
The multi-function shower head in the present invention comprises a shower head body and a grip combined together, a bubble unit, a sponge unit, a massage unit and a scrubbing unit to be additionally attached on the shower head body, and an electric heat case.
The shower head body comprises an outlet disc at the top, an upper gate disc at the middle and a lower gate disc at the bottom assembled together. The outlet disc has many water holes arranged along three concentric circles, and the upper and the lower gate disc respectively have three concentric ring grooves corresponding to one another and a long groove formed radially for a cylindrical gate to fit in. The cylindrical gate has three water holes perforated in its wall in unlinear position. The water holes in the outlet disc and the three concentric ring grooves in the upper and the lower gate disc form three water passages and communicate with one of the three holes in the cylindrical gate by turning said gate.
The grip has its top combined with the shower head body, provided with three tubular passages, one for water to run through, another for soap solution to run through, and another for a wire rope to go through. The wire rope has its top end connected with a shaft of a swinging iron block in the upper section of the grip and its bottom end connected with a shaft of a motor such that the wire rope can be rotated by the motor and thus rotates the swinging iron block. The shaft of said iron block is also connected with a pair of gears to rotate a cylindrical shaft which is set passing through the center of the shower head body and a square shaft of any extra unit for bubbling, massaging, etc. can be additionally combined with by inserting said shaft in a square hole in said cylindrical shaft.
The extra electric heating case comprises three chambers one for storing soap solution, another for heating water and another for mounting the motor to rotate the wire rope and a blower.
The soap solution is to be controlled in sending out in one tubular passage in the grip and then to the shower head body by a push button switch installed in the grip.
An electric time circuit is provided to control a water supply supplying water in a heating chamber in the electric heat case for a preset period of time.
In addition, an electric time circuit is provided for turning on and off the heater to heat the water in the heating chamber for a pre-set period of time to produce hot vapor to be sent to the shower head body.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the multi-function shower head in the present invention.
FIG. 2 is a cross-sectional view of the push button switch in the present invention.
FIG. 3 is an cross-sectional view of the multi-function shower head in the present invention.
FIG. 4 is a side view of the multi-function shower head in the present invention.
FIGS. 5a and 5b show an elevational view of the wire rope and its accessory, respectively, in the present invention.
FIG. 6 is a front view of the bubble unit in the present invention.
FIG. 7 is a cross-sectional view of the bubble unit in the present invention.
FIG. 8 is a front view of the sponge unit in the present invention.
FIG. 9 is a cross-sectional view of the sponge unit in the present invention.
FIG. 10 is a front view of the massage unit in the present invention.
FIG. 11 is a cross-sectional view of the massage unit in the present invention.
FIG. 12 is a front view of the scrubbing unit in the present invention.
FIG. 13 is a cross-sectional view of the scrubbing unit in the present invention.
FIG. 14 is an exploded perspective view of the multi-function shower head in the present invention.
FIG. 15 is a cross-sectional view of the water hose for the multi-function shower head in the present invention.
FIG. 16 is a perspective view of the multi-function shower head connected with the electric heat case in the present invention.
FIG. 17 is a cross-sectional view of the electric head case in the present invention.
FIG. 18 is a cross-sectional view of the one-way valve for the connecting tube in the present invention.
FIG. 19 is the diagram of the electric circuit for controlling water supply to the shower head in the present invention.
FIG. 20 is the diagram of the electric circuit for controlling the heater in the present invention.
FIG. 21 is a perspective view of the shelf in the present invention.
FIG. 22 is a perspective view of the multi-function shower head practically installed in a bathroom.
DETAILED DESCRIPTION OF THE INVENTION
The multi-function shower head 1 in the present invention, as shown in FIGS. 1, 3, 4 and 16, comprises a shower head body 4 and a grip 11 combined together, an extra bubble unit A, an extra sponge unit B, an extra massage unit C, an extra scrubbing unit D and an extra electric heat case 6 as the main components.
The grip 11, as best shown in FIG. 3, has three hollow tubular passages 21, 22 and 23 in its interior. A wire rope 31 is disposed in the passage 21, having its upper end fixed firmly at a shaft 321 of a swinging iron block 32 and its lower end connected with a shaft of a motor M, as shown in FIG. 5. The wire rope 31 can be rotated by the motor M, transmitting rotation to the shaft 321, which in turn rotates a gear 322 and accordingly a gear 323 engaging with the gear 322. As the gear 323 is fixed on a cylindrical shaft 33, on which the extra bubble unit A, or the extra massage unit B, etc. as shown in FIGS. 6-13 can be additionally assembled respectively so as to be rotated by the shaft 33.
The extra bubble unit A, as best shown in FIGS. 6 and 7, comprises filter nets A1 and A2 and a fan blade A3 and a square shaft A31 fitting in a square central hole 331 of the shaft 33 so as to be rotated by the motor M. Thus, when the bubble unit A assembled with the shower head 1 is put and rotated in the water in a bathtub, it can give rise to bubbles by striking the water mixed with soap solution or the like.
The extra sponge unit B as shown in FIGS. 8 and 9 comprises a sponge B1 and a square shaft B11 fitting in the hole 331 of the shaft 33 so that the sponge B1 can be rotated and scrub clean a human body with soap solution added on.
The extra massage unit C shown in FIGS. 10 and 11 comprises a massage semi-circular member C1 and a square shaft to fit in the hole 331 of the shaft 33 so as to be vibrated by the unbalanced movement of the swinging iron block 32 rotated by the wire rope 31.
The scrubbing unit D as shown in FIGS. 12 and 13 comprises a sponge or rubber D1 having a rough surface so as to scrub and clean a human body with water coming from passages D2, which are axially formed therethrough, when the scrubbing unit D is assembled with the shower head. Those four kinds of units can be selectably used in bathing.
The electric heat case 6 as shown in FIG. 17 comprises a storing chamber 61 for keeping soap solution therein. The storing chamber 61 has an outlet 612 and to communicate the tubular passage 22 to supply soap solution to the shower head body 4 by operating the push button switch 24. The push button switch 24 as shown in FIG. 2, comprises two valve openings 241, 242, two balls 2421, and two springs 2411 and 2412 urging said balls in the tubular passage 22, and a push button 243 set sidewise in the wall of the grip 11 and a spring 2431 under the button 243 to push a push block 2432. When the push button 243 is pressed to move the spring 2431 and the push block 2432 in order, the push block 2432 can move the balls 2421, 2422 to leave the valve openings 241 and 242 so that the soap solution can enter the upper section of the tubular passage 22 through the valve opening 241. On the contrary, if the button 243 is released to recover its original position, the valve openings 241 and 242 are automatically blocked by the balls 2412 and 2422 urged by the springs 2411 and 2422.
A shower head body 4 as shown in FIG. 14 is firmly mounted at the upper end of the grip 11, having a cylindrical gate 41, a lower gate disc 42, an upper gate disc 43, an outlet disc 44, and two anti-leak gaskets 45 and 46 combined together. The cylindrical gate 41 is fitted in a long groove 424 in the lower gate disc 42 and the upper gate disc 43, having three inlet holes 411, 412 and 413 formed irregularly not on a straight line. The lower gate disc 42 is provided with three concentric ring grooves 421, 422 and 423 and the upper gate disc 43 with three concentric ring grooves 431, 432 and 433. The outlet disc 44 is provided with a plurality of holes 441, 442 and 443 located along three concentric circles to correspond to the two groups of three concentric ring grooves 421, 422, 423, 431, 432, and 433, forming three--one of the outer, another of the middle and another of the inner--water passages 451, 452 and 453, as best shown in FIG. 3. After the outlet disc 44, the upper gate disc 43 and the lower gate disc 42 are orderly assembled together with screws, the water coming from the tubular passage 23 can be selected to flow through one of the three inlet holes 411, 412, and 413 in the gate 41, one of three round holes 4211, 4221, and 4231 in the three ring grooves 421, 422 and 423 and then finally through one of the holes 441, 442 and 443 in the outlet disc 44 as sprayed water in one of the three concentric circles a, b and c as shown in FIG. 4. In addition, for preventing the shower head body 4 from leaking, the anti-leak gaskets 45 and 46 are respectively pinched between the lower and the upper gate disc and the grip 11.
The shower head 1 can also be connected with a water hose 5 as shown in FIG. 16. The water hose 5, as best shown in FIG. 15, has three water passages 51, 52 and 53 which are respectively led to the hollow tubular passages 21, 22, 23 in the shower head 1. The electric heat case 6 is divided into three chambers. One of said chambers, as shown in FIGS. 16 and 17, is for installing the motor M therein, another is a storing chamber 61 for soap solution and another a heating chamber 62. The storing chamber 61 has a lid 611 for filling in soap solution and an outlet tube 612 connected to communicate the hollow tubular passage 22 the shower head 1 through the water passage 52 in the hose 5. The heating chamber 62 has an electric heater 621 fixed therein for heating and vaporizing the water therein, and the hot vapor produced therein is to be mixed; with air blown therein through a connecting tube 64 by a blower 63 connected with the motor M. Then the vapor mixed with air is to run out of a hole 623 in an upper horizontal wall 622 in an air chamber 65, from which the vapor mixed with air runs out through an outlet tube 651 to a place it is used as sauna vapor. The connecting tube 64 is provided with a one-way valve 641 at its end as shown in FIG. 18 to prevent the vapor from running back in the blower. In addition, a safety valve 66 is mounted at the upper wall of the air chamber 65 to let out an excessively high pressure vapor through a ball 661 therein to prevent explosion caused by too high pressure of the vapor therein. A filling tube 624 is provided at the side wall to fill water in the heating chamber 62.
A water inlet pipe 680 is provided to supply water to the shower head 1 from a suitable water source (not shown). The inlet end of the water inlet pipe 680 is divided into a first branch 681 connected to the electric heat case 6 to feed water into the heating chamber 62 and a second branch 683 by-passing the electric heat case 6 to communicate the water passage 53 in the hose 5. A water control valve assembly 68 is assembled in the inlet end of the pipe 680 with a valve 682 to control the water flow in the pipe 680 either into the first branch 681 or the second branch 683.
The wire rope 31 and the blower 63 are respectively connected with both ends of the shaft of the motor M in such a way that the motor rotates only the wire rope 31 when it rotates clockwise and rotates only the blower 63 when it rotates counterclockwise. This function of two different rotations of the motor M is attained by two needle bearings of one way rotation fixed at each end of the shaft.
A time switch 671 shown in FIG. 16 is provided at the lower section of the electric heat case 6 and marked as S in the diagram of a water supply control electric circuit illustrated in FIG. 19, functioning as an operator of an electro-magnetic valve Re installed at a side wall of the electric heat case 6. When the switch 671 is turned on, a plus signal is sent out of IC1 to actuate the electro-magnetic valve Re, which is then energized to begin to supply water to the shower head. In addition, the supplying time is also counted by IC1, and when the preset time ends, a minus signal is sent out of IC3 to IC5 to turn off the electromagnetic valve Re. Then the water is to be stopped. The time switch S can be freely used to supply water to the shower head for an adjustable preset period of time, saving manual operation of supplying water.
A time switch 672 is also provided at a lower side wall of the electric heat case 6 near the switch 671, for controlling the operation time of a heater tube 621 in the heating chamber 62. Thus, the water in said chamber 62 can be heated up for a preset period of time so as to be vaporized. The switch 672 is represented as S in the diagram of an electric circuit shown in FIG. 20. When the switch S is turned on, a plus signal is sent out of IC3 to IC1 to actuate a relay to energize the heater tube 621 and IC2 to start to count the heating time. When the preset time for heatoff the relay to cut off the heater tube 621.
Lastly, the shower head 1 and the electric heat case 6 are disposed near above a bathtub 7 as shown in FIG. 22. Then, the shower head 1 can be used as a faucet, to save the cost of a faucet. A shelf 8 as shown in FIG. 21 can be installed to put on attachable units such as the bubble unit, the sponge unit, etc. for convenient use.
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A multi-function shower head comprising a shower head body mounted at the upper end of a grip and several units for making bubbles, message, scrubbing, etc. passible to be selectably and additionally attached on the shower head body. The shower head body is provided with three water passages to be selectably connected with a tubular water passage in the grip for water to run out of many small holes in the outer surface of the shower head body. The grip also has a tubular passage for soap solution and a tubular passage for a wire rope to fit in and rotated by a motor so as to rotate a cylindrical shaft used for combining any of the several extra units for different purposes of bathing.
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BACKGROUND OF THE INVENTION
The present invention relates to storage structures such as parking structures, and more particularly, to apparatuses for turning stored articles, such as motor vehicles.
A typical parking structure (e.g., Japanese Unexamined Patent Publication No. 8-60887) includes an entry station, storing compartments, elevator shaft, and elevator. The entry station is where the cars enter and exit the parking structure and is located on the ground level. The storing compartments are used to store the cars and are located on floors above the ground level or floors underground. The elevator shaft connects the entry station and the storing compartments. The elevator travels through the elevator shaft to carry the cars between the entry station and the storing compartments.
The elevator includes a comb-like lifting platform to carry cars through the elevator shaft. The platform is lifted or lowered in the elevator shaft while carrying cars. A turntable having a comb-like carrying portion is arranged on a movable center tray provided in the entry station. In the entry station, the turntable is rotated to shift its carrying portion between a first position, at which cars are transferred between the carrying portion and the platform, and a loading position, at which cars may enter and exit the parking structure. The turntable also functions as an apparatus for turning cars so that they may always be driven in a forward direction when entering and exiting the parking structure.
However, to stabilize rotation of the turntable, especially when carrying a car, a main rail must be provided on the movable center tray to support the turntable during rotation especially when carrying a car. A pair of auxiliary rails must also be provided on opposite sides of the turntable. Furthermore, when lowering the platform of the elevator below ground level, the center tray, the turntable, and the auxiliary rails must be moved away from the center portion of the entry station.
Therefore, in the prior art, the movable center tray is separate from the pair of auxiliary rails. When lowering the platform, the movable center tray, the turntable, and one of the auxiliary rails are moved to one side of the entry station. This structure reduces the space required to permit the lowering of the platform. However, a large space must be provided in the entry station to accommodate the turntable.
SUMMARY OF THE INVENTION
Accordingly, it is an objective of the present invention to save space in the entry station by arranging the turning apparatus outside the entry station. To achieve the above objective, the present invention provides a storage structure having an entry chamber for receiving articles, a storage area for storing the articles, a lift passage for connecting the entry chamber and the storage area, and a lift for conveying the articles through the lift passage between the entry chamber and the storage area. The storage structure includes a turning chamber provided separately from the entry chamber and connected to the lift passage for changing the orientation of an article. A turntable device is supported in the turning chamber to receive an article from the lift within the lift passage and to transfer an article to the lift. The turntable device includes a rotatable carrying surface and two auxiliary supports. One auxiliary support is located on each of two opposite sides of the turntable device for supporting the carrying surface when the carrying surface rotates. The carrying surface is movable between a position within the lift passage and a position outside of the lift passage.
Other aspects and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, illustrating by way of example the principals of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIG. 1 is a schematic cross-sectional view showing a parking structure according to a first embodiment of the present invention;
FIG. 2 is a schematic cross-sectional view taken along line 2--2 in FIG. 1;
FIG. 3 is a schematic cross-sectional view taken along line 3--3 in FIG. 2 showing the movable center tray, the turntable, the side trays, the auxiliary rails, and the movable storage trays at a predetermined position;
FIG. 4 is a schematic cross-sectional view showing the turntable moved into the turning section from the position shown in FIG. 3;
FIGS. 5(a) and (b) are diagrammatic views showing the movable center tray, the turntable, the side tray, the auxiliary rails, and the movable storage trays located at predetermined positions;
FIG. 6 is a partial perspective view showing the movable center tray, the turntable, the side tray, the auxiliary rails, and the movable storage trays;
FIG. 7 is a view corresponding to FIG. 2 showing a second embodiment of a parking structure according to the present invention;
FIG. 8 is a schematic cross-sectional view taken along line 8--8 in FIG. 7 showing the movable center tray, the turntable, the side tray, the auxiliary rails, and the movable storage trays at a predetermined position;
FIG. 9 is a schematic cross-sectional view showing the turntable moved into the turning section from the position shown in FIG. 8;
FIGS. 10(a) and (b) are diagrammatic views showing the movable center tray, the turntable, the side tray, the auxiliary rails, and the movable storage trays located at predetermined positions; and
FIG. 11 is a partial perspective view showing the movable center tray, the turntable, the side tray, the auxiliary rails, and the movable storage trays of FIG. 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of a parking structure serving as a storage structure according to the present invention will now be described with reference to FIGS. 1 to 6.
An underground parking structure having first, second, third, fourth, and fifth storage blocks 1, 4, 5, 6, 7 is shown in FIG. 1. The first storage block 1 includes an entry station 2 located on the ground level, or the uppermost level, and an underground storage area 3 (refer to FIG. 2). The second, third, fourth, and fifth storage blocks 4, 5, 6, 7 are arranged in a row with the first storage block 1.
A turning area 8 (also serving as a car storing section) is defined at basement level one of the first storage block 1. Car storing sections 9, 10, 11 are defined at basement levels two, three, and four, respectively. A transferring section 12 is defined at basement level five (the lowermost level) of the first, second, third, fourth, and fifth storage blocks 1, 4, 5, 6, 7. Four guide rails 13, 14, 15, 16 having a predetermined distance between one another extend vertically between the entry station 2 and the transferring section 12 (refer to FIGS. 3 and 4).
The space between the guide rails 13, 14, 15, 16 extending through the entry station 2, the turning area 8, the storing sections 9, 10, 11, and the transferring section 12 define a lift passage, or an elevator shaft 17. Storing compartments 18 are provided on each side of the elevator shaft 17 in the turning area 8 and the storing sections 9, 10, 11. The entry station 2 is connected with each storing compartment 18 through the elevator shaft 17.
The second, third, fourth, and fifth 4, 5, 6, 7 storage blocks differ from the first storage block 1, which is shown in FIG. 2, in that the turning area 8 is not provided at basement level one. The structure of basement levels one to four of the second, third, fourth, and fifth storage blocks 4, 5, 6, 7 are substantially the same as the structure of basement levels two to four of the first storage block 1. Thus, the storage blocks 4, 5, 6, 7 are each provided with storing sections 19, elevator shafts 17, and lifts, or elevators 20.
Structure of the Elevators 20
A winch 21 is provided above each elevator shaft 17. The winch 21 is connected to four chains 22, 23, 24, 25 that extend through the guide rails 13, 14, 15, 16, respectively. In addition to the guide rails 13, 14, 15, 16 and the associated chains 22, 23, 24, 25, each elevator 20 includes a pair of lifting platforms 26, 27.
Each lifting platform 26, 27 includes a drive portion 28 and a carrying portion 29. The drive portion 28 of the left platform 26 (as viewed in FIG. 3) includes a support arm 30 connected to the pair of guide rails 13, 14. The drive portion 28 of the right platform 27 (as viewed in FIG. 3) includes a support arm 30 connected to the guide rails 15, 16. The ends of the support arms 30 are supported by the associated guide rails 13, 14, 15, 16 to enable the arms 30 to move vertically. The lower ends of the chains 22, 23, 24, 25 are connected to the associated ends of the support arms 30. Accordingly, the support arms 30 are moved in cooperation with each other by the winch 21. Each carrying portion 29 is defined by comb-like forks 31 that are secured to the support arms 30. The drive portions 28 are lifted and lowered in cooperation with each other through the elevator shaft 17 together with the associated carrying portions 29 when the winch 21 lifts and lowers the chains 22, 23, 24, 25.
The drive source (not shown) of the elevator 20 provided for each storage blocks 4, 5, 6, 7 may be arranged in a corresponding traveling passage 44 at basement level five. In this case, pulleys are provided in the ceiling of basement level one to connect the drive source to the elevator 20 with chains.
Structure of the Entry Station 2
A pair of rails 32 provided with a plurality of rollers 33 extend along the ceiling of the left storing compartment 18 (as viewed in FIG. 2) in the turning area 8 and the floor of the entry station 2. The rails 32 extend horizontally and parallel to each other with a predetermined distance therebetween. A movable tray 34 is movably supported along the rails 32 to carry cars that enter and exit the entry station 2. The rollers 33 move the movable tray 34 into the entry station 2 and out of the entry station 2.
In the same manner as the lifting platforms 26, 27, comb-like carrying portions defined by forks 35 are provided at the left and right sides of the movable tray 34. When the lifting platforms 26, 27 of the elevator 20 are lifted or lowered with the movable tray 34 located in the entry station 2, the forks 31 of the carrying portions 29 of the lifting platforms 26, 27 may be arranged between or moved through the forks 35 of the movable tray 34. Accordingly, storing articles, or cars 65, may be transferred between the forks 35 of the movable tray 34 and the lifting platforms 26, 27 in the entry station 2.
Structure of the Car Storing Sections 9, 10, 11
A pair of upper rails 37 and a pair of lower rails 38, each provided with a plurality of rollers 36, extend along the floor of the storing compartments 18 and into the elevator shaft 17 at basement levels two, three, and four. Each pair of upper rails 37 and lower rails 38 extend horizontally, and the rails of each pair extend parallel to each other with a predetermined distance in between.
Movable trays 39, 40 are movably supported along the upper rails 37 to carry cars between the storing compartments 18 and the elevator shaft 17. Similar movable trays 41, 42 are also movably supported along the lower rails 38. The rotation of the rotors 36 moves the associated trays 39, 40, 41, 42 between the elevator shaft 17 and the storing compartments 18. The plurality of rollers 36 include drive rollers and driven rollers.
Comb-like carrying portions defined by forks 43 are provided at the left and right sides of each movable tray 39, 40, 41, 42. The structure of the forks 43 is identical to the forks 31 of the lifting platforms 26, 27. When the lifting platforms 26, 27 are lifted or lowered with the movable trays 39, 40, 41, 42 located in the elevator shaft 17, the forks 31 of the platforms 26, 27 may be arranged between or moved through the forks 43. Accordingly, cars 65 may be transferred between the forks 43 of the movable trays 39, 40, 41, 42 and the lifting platforms 26, 27 in the elevator shaft 17.
Structure of the Transferring Section 12
A traveling passage 44 is provided at basement level five of each storage block 1, 4, 5, 6, 7 extending through the middle of the transferring section 12. Rails 45 extend continuously along the floor of the traveling passage 44. A carriage 46 is supported on the rails 45.
Carrying portions defined by forks 47 are provided at the left and right sides of the carriage 46. The forks 47 are identical to the forks 31 at the carrying portions 29 of the lifting platforms 26, 27. When the lifting platforms 26, 27 of one of the elevators 20 are lifted or lowered with the carriage 46 located at the associated traveling passage 44, the forks 31 of the platforms 26, 27 may be arranged between or moved through the forks 47 of the carriage 46. Accordingly, cars 65 may be transferred between the forks 47 of the carriage 46 and the lifting platforms 26, 27 in the elevator shafts 17.
Structure of the Turning Area 8
A pair of upper rails 49 provided with a plurality of rollers 48 extend along the floor of the storing compartments 18 and into the elevator shaft 17 at basement level one. A pair of lower rails 50 provided with a plurality of rollers 48 extend along the floor of the left storing compartment 18 (as viewed in FIG. 2) and the into the elevator shaft 17. Each pair of upper rails 49 and lower rails 50 extend horizontally, and the rails of each pair extend parallel to each other with a predetermined distance in between.
A movable center tray 51 and a pair of side trays 52, 53 are supported on the lower rails 50. Movable trays 54, 55 are supported on the upper rails 49. The rotation of the rollers 48 moves the movable center tray 51 between a first position in the elevator shaft 17 (refer to FIG. 3) and a second position in the associated storing compartment 18 (refer to FIG. 4). A turntable 56 is supported on the center tray 51. The turntable 56 is rotatable about a shaft 57. Wheels (not shown) are provided under the turntable and supported on the center tray 51 by an arc-like main rail (not shown).
The turntable 56 has circular ends and carrying portions 59 defined on each side by forks 60. The forks 60 are identical to the forks 31 of the lifting platforms 26, 27. Rotation of the turntable 56 arranges the row of forks 60 on each side of the turntable 56 parallel to the support arms 30, as shown in FIG. 3. When the lifting platforms 26, 27 are lifted or lowered with the center tray 51 located in the elevator shaft 17 at the first position P (refer to FIG. 3), the forks 31 of the platforms 26, 27 may be arranged between or moved through the forks 60 of the turntable 56. Accordingly, cars 65 may be transferred in the elevator shaft 17 between the forks 60 of the turntable 56 and the forks 31 of the lifting platforms 26, 27.
The pair of side trays 52, 53 are provided on each side of the movable center tray 51 and are separated from the center tray 51. The left side tray 52 (as viewed in FIG. 3) is supported on the lower rails 52 and movable in directions D. The right side tray 53 is fixed at a position adjacent to the elevator shaft 17 in the associated storing compartment 18. Arc-like auxiliary rails 61, 62 are provided on the side trays 52, 53 to support the wheels (not shown) of the turntable 56 during rotation of the turntable 56.
The pair of movable trays 54, 55, shown in FIG. 3, are supported on the upper rails 49 and are movable in directions D. Accordingly, the rotation of the rollers 48 moves the movable trays 54, 55 between a position Q (refer to FIG. 4) in the elevator shaft 17 and a position in the associated storing compartments 18 (refer to FIG. 3).
Carrying portions 63 defined by forks 64 are provided on each side of the movable trays 54, 55. The forks 64 are identical to the forks 31 of the lifting platforms 26, 27. When the lifting platforms 26, 27 are lifted or lowered with the movable trays 54, 55 located in the elevator shaft 17 (refer to FIG. 4), the forks 31 of the platforms 26, 27 may be arranged between or moved through the forks 64 of the movable trays 54, 55. Accordingly, cars 65 may be transferred in the elevator shaft 17 between the forks 64 of the movable trays 54, 55 and the forks 31 of the lifting platforms 26, 27.
As shown in FIG. 5(a), moving plane E, in which the turntable 56 on the center tray 51 moves, is lower than moving plane F, in which the movable trays 54, 55 move. Accordingly, the movable trays 54, 55 do not collide against the turntable 56 no matter where the turntable 56 is located.
The center tray 51, the side tray 52, and the auxiliary rail 61 are located at positions lower than the moving plane F of the movable trays 54, 55. The fixed side tray 53 and the auxiliary rail 62 are also located at positions lower than the moving plane F of the movable trays 54, 55. Accordingly, the movable trays 54, 55 do not collide against the side trays 52, 53 and the auxiliary rails 61, 62. Furthermore, as shown in FIG. 5(b), the wheels (not shown) of the turntable 56 roll along the same plane G on the main rail (not shown) of the center tray 51 and the auxiliary rails 61, 62.
Parking in the Underground Parking Structure
The following steps 1 and 2 are carried out to store a car 65 in the storing compartments 18 of the turning area 8 at basement level 1 of the first storage block 1.
Step 1: Transferring a car 65 from the entry station 2
As shown in FIG. 2, the movable tray 34 is first moved into the entry station 2. The elevator 20 holds the lifting platforms 26, 27 at a position lower than the movable tray 34. A car 65 is moved forward into the entry station 2 and onto the forks 35 of the movable tray 34. The car 65 is then transferred to the lifting platforms 26, 27 from the movable tray 34 by lifting the platforms 26, 27. The movable tray 34 then moves leftward out of the entry station 2. Afterwards, the car 65 held on the lifting platforms 26, 27 is lowered to the turning area 8.
Step 2: Transferring the car 65 in the turning area 8
One of the movable trays 54, 55 (e.g., the left tray 54 as viewed in FIG. 2) is moved into the elevator shaft 17. The car 65 carried on the lifting platforms 26, 27 is lowered to a position above the movable tray 54. In this state, the movable center tray 51, the turntable 56, the movable side tray 52, and the auxiliary rail 61 are moved to positions outside of the elevator shaft 17. As the lifting platforms 26, 27 are lowered, the car 65 is transferred onto the movable tray 54. The movable tray 54 then carries the car 65 leftward out of the elevator shaft 17 and into the associated storing compartment 18 at basement level one. The right movable tray 55 shown in FIG. 2 is operated in the same manner as the left movable tray 54.
The following steps 1 and 2 are carried out to store a car 65 into the storing sections 9, 10, 11 (basement levels two, three, and four).
Step 1: Transferring a car 65 from the entry station 2
A car 65 is transferred from the entry section 2 in the same manner as when moving the car 65 into the turning area 8. The lifting platforms 26, 27 carrying the car 65 are lowered past the turning area 8 and to the designated storing section 9, 10, 11. In this state, the movable center tray 51, the turntable 56, the left side tray 52, and the auxiliary rail 61 are moved to positions outside the elevator shaft 17 at the turning area 8.
Step 2: Transferring the car 65 in the storing sections 9, 10, 11
Among the movable trays 39, 40, 41, 42, the movable tray 39 at basement level two, for example, is moved into the elevator shaft 17. The lifting platforms 26, 27 holding the car 65 are moved to a position above the movable tray 39. The lifting platforms 26, 27 are further lowered to transfer the car 65 onto the movable tray 39. The movable tray 39 carrying the car 65 is moved leftward out of the elevator shaft 17 and into the storing compartment 18. The car 65 is transferred in the same manner when employing the other movable trays 40, 41, 42. However, if a car 65, which has already been stored in one of the storing sections 9, 10, 11, obstructs the storing of the new car 65, the obstructing car 65 is temporarily moved to another level and then returned to its original position after the new car 65 is stored in the designated storing compartment 18.
To store the car 65 in one of the other storage blocks 4, 5, 6, 7 instead of the first storage block 1, the car 65 held on the lifting platforms 26, 27 is first lowered to basement level five in the first storage block 1 and transferred onto the forks 47 of the carriage 46 in the traveling passage 44 of the transferring section 12. The carriage 46 carries the car 65 through the transferring sections 12 (basement level five) of the other storage blocks 4, 5, 6, 7. When the carriage 46 reaches the designated storage blocks 4, 5, 6, 7, the car 65 is transferred to the lifting platforms 26, 27 of the associated elevator 20. The car 65 is then lifted and stored in the designated storing compartment 18.
The following steps 1 to 3 are performed when retrieving a car 65 from the storing compartment 18 of the turning area 8 located at basement level one of the first storage block 1.
Step 1: Rotating a car 65 in the turning area 8
Among the movable trays 54, 55, for example, the left movable tray 54 carrying a car 65 is moved into the elevator shaft 17. In this state, the movable center tray 51, the turntable 56, the left side tray 52 and the auxiliary rail 61 are moved to positions outside the elevator shaft 17. The lifting platforms 26, 27 of the elevator 20 are located at a position lower than the movable tray 54. When the lifting platforms 26, 27 are lifted, the car 65 is transferred to the lifting platforms 26, 27 from the movable tray 54. Afterwards, the movable tray 54 is moved out of the elevator shaft 17.
The movable center tray 51, the turntable 56, the side tray 52, and the auxiliary rail 61 are then moved into the elevator shaft 17. This arranges the movable auxiliary rail 61 and the fixed auxiliary rail 62 on each side of the turntable 56. When the lifting platforms 26, 27 carrying the car 65 are lowered, the car 65 is transferred onto the turntable 56.
The turntable 56 carrying the car 65 is rotated 180 degrees along the main rail (not shown) of the movable center tray 51 and the auxiliary rails 61, 62 of the associated side trays 52, 53. This turns the car 65 by 180 degrees from the position of the car 65 when it entered the parking structure.
Step 2: Transferring the car 65 from the turning area 8
The lifting platforms 26, 27 of the elevator 20 are held at a position lower than the turntable 56, which is carrying the car 65. The lifting platforms 26, 27 are then lifted to receive the car 65 from the turntable 56. The lifting platforms 26, 27 carrying the car 65 are then lifted to the entry station 2. The right movable tray 55 is employed in the same manner as the left movable tray 54.
Step 3: Transferring the car 65 to the entry station 2
The movable tray 34 is moved out of the entry station 2 before the lifting platforms 26, 27 carrying the car 65 are lifted into the entry station 2. When the car 65 is lifted into the entry station 2, the lifting platforms 26, 27 are located above the movable tray 34. The movable tray 34 then moves into the entry station 2 and the lifting platforms 26, 27 are lowered to transfer the car 65 onto the movable tray 34. The car 65 is then driven forward on the movable tray 34 and out of the entry station 2.
The following steps 1 to 3 are performed when retrieving a car 65 from the storing sections 9, 10, 11 of the associated basement levels two to four of the first storage block 1.
Step 1: Transferring a car 65 from the storing sections 9, 10, 11
The movable tray 39 in the storing section 9, like the other similar trays 40, 41, 42 in the storing section 10, 11, is moved into the elevator shaft 17 with a car 65 held thereon. The lifting platforms 26, 27 of the elevator 20 are previously arranged at a position lower than the movable tray 39. The lifting platforms 26, 27 are then lifted to receive the car 65 from the movable tray 65.
Step 2: Turning the car 65 in the turning area 8
The lifting platforms 26, 27 carrying the car 65 are lifted into the turning area 8 while the movable center tray 51, the turntable 56, the side tray 52 and the auxiliary rail 61 are located outside the elevator shaft 17. Afterwards, the car 65 is rotated by 180 degrees from its position when entering the parking structure. The turning of the car 65 is carried out in the same manner as when retrieving the car 65 from the storing compartments 18 of the turning area 8, which was described earlier.
Step 3: The transferring of the car 65 from the turning area 8 and from the entry station 1 are carried out in the same manner as when retrieving the car 65 from the storing compartments 18 of the turning area 8.
To retrieve a car 65 from the second, third, fourth and fifth storage blocks 4, 5, 6, 7, the car 65 is first transferred onto the lifting platforms 26, 27 of the associated storage block 4, 5, 6, 7. The lifting platforms 26, 27 are then lowered into the traveling passage 44 at the transferring section 12 (basement level five) to transfer the car 65 onto the forks 47 of the carriage 46. At basement level five, the carriage 46 moves the car 65 past the storage blocks 4-7 and to the traveling passage 44 in the transferring section 12 of the first storage block 1. The car 65 is then transferred onto the lifting platforms 26, 27 of the first storage block 1 from the carriage 46. Afterwards, the car 65 is transferred to the turning area 8 and rotated by 180 degrees with respect to the position of the car 65 when it entered the parking structure. The turning of the car 65 is carried out in the same manner as when retrieving the car 65 from the storing compartments 18 of the turning area 8. The rotated car 65 is then moved out of the parking structure from the entry station 2.
The first embodiment has the following features.
The turning area 8 including the elevator shaft 17 is provided at a location other than the entry station 2. In the turning area 8, the turntable 56 is rotatably coupled to the movable center tray 51. The rotation of the turntable 56 arranges the turntable 56 to position P. Cars 65 are transferred between the carrying portion 59 of the turntable 56 and the lifting platforms 26, 27 of the elevator 20 in the elevator shaft 17. The turntable 56, functioning as a turning apparatus for cars 65, is arranged outside the entry station 2. Thus, space for accommodating the turntable 56 when it is moved out of the elevator shaft 17 need not be provided in the entry station 2. This saves space necessary for the entry station 2, which is exposed above the ground.
In the turning area 8, the movable center tray 51 may be moved into and out of the elevator shaft 17. This allows the lifting platforms 26, 27, which carry the car 65, to move through the elevator shaft 17. Accordingly, a car 65 may be carried smoothly between the entry station 2 and the storing compartments 18.
The auxiliary rails 61, 62 that support the turntable 56 during rotation of the turntable 56 are provided on the side trays 52, 53, respectively, and on each side of the movable center tray 51. This enables stable rotation of the turntable 56 when carrying the car 65.
The turning area 8, the elevator shaft 17 , and the storing compartments 18 are provided at a location separate from the location of the entry station 2. The movable trays 54, 55 are provided in the turning area 8 and are movable in the same moving directions D as the movable center tray 51. This enables the movable trays 54, 55 to be moved between the elevator shaft 17 and the storage compartments 18. The carrying portions 63 of the movable trays 54, 55 may be moved to position Q at which a car 65 is transferred between movable trays 54, 55 and the lifting platforms 26, 27 of the elevator 20 in the elevator shaft 17. The structure of the turning area 8 enables the cars 65 to be stored therein. This improves the storing efficiency of the parking structure.
The side trays 52, 53 and the auxiliary rails 61, 62 move relatively to the movable center tray 51 and the turntable 56 in a plane lower than the movable trays 54, 55. Thus, as shown in FIG. 5(a), the movable tables 54, 55 may be moved between the elevator shaft 17 and the associated storing compartments 18 without colliding against the turntable 56. Accordingly, the cars 65 may be moved smoothly on the movable tables 54, 55.
When retaining cars 65 from the parking structure, the movable center tray 51, the turntable 56, the side tray 52, and the auxiliary rail 61 are moved to a position shown in FIG. 5(b). At this position, the turntable 56, which carries a car 65, is rotated supported by the movable center tray 51 and the auxiliary rails 61, 62 of the associated side trays 52, 53. This enables the car 65 to be smoothly turned around in the turning area 8.
As described above, the movable trays 54, 55 are moved between the elevator shaft 17 and the associated storage compartments 18 without colliding against the turntable 56 regardless of where the turntable 56 is located. In other words, the turntable 56 need not be moved to avoid collision with the movable trays 54, 55 when moving the movable trays 54, 55. Thus, among the two side trays 52, 53 arranged on each side of the movable center tray 51, the position of the side tray 53 may be fixed. Accordingly, a driving mechanism for the side tray 53 need not be provided.
Among the two side trays 52, 53 arranged on each side of the movable center tray 51, the left side tray 52 is movable in the same moving directions D as the movable center tray 51. This enables smooth movement of the movable center tray 51.
The turning area 8 is provided adjacent to the entry station 2. Thus, car storing sections are not provided between the turning area 8 and the entry station 2. This allows the cars 65 to be carried into the turning area 8 and then transferred to the entry station 2 as soon as the car 65 is turned around. Accordingly, the car 65 may be turned around efficiently when retrieving the car 65 from the parking structure.
A second embodiment of a parking structure according to the present invention will now be described with reference to FIG. 1 and FIGS. 7 to 11. FIGS. 1, 2, 3, 4, 5(a), 5(b), and 6 illustrating the first embodiment correspond to FIGS. 1, 7, 8, 9, 10(a), 10(b), and 11 illustrating the second embodiment.
The features of the second embodiment that differ from that of the first embodiment will now be described. The distance L between the upper rails 49 and the lower rails 50 of the first embodiment, as shown in FIGS. 5(a), 5(b), and 6 is greater than the distance L between the upper rails 49 and the lower rails 50 of the second embodiment, as shown in FIGS. 10(a), 10(b), and 11. Thus, in the first embodiment, this enables the turntable 56 in addition to the movable center tray 51, the side trays 52, 53, and the auxiliary rails 61, 62 to be arranged at a position lower than the moving plane F of the movable trays 54, 55. In comparison, the moving plane E of the turntable 56 in the second embodiment coincides with the moving plane F of the movable trays 54, 55.
In the second embodiment, the pair of side trays 52, 53 supporting associated auxiliary rails 61, 62 are movable in the same moving directions D as the movable center tray 51. In the first embodiment, only the left side tray 52 is movable. The position of the right side tray 53 is fixed.
As shown in FIGS. 10(a) and 10(b), to avoid collision between the movable trays 54, 55 and the turntable 56 when moving the movable trays 54, 55 between the elevator shaft 17 and the associated storing compartments 18, the movable center tray 51 and the turntable 56 are moved together with the movable trays 54, 55. The side trays 52, 53 and the auxiliary rails 61, 62 are also moved to allow movement of the movable center tray 51.
Although only two embodiments of the present invention have been described so far, it should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the invention may be embodied in the following forms.
The turning area 8 need not be provided with the storing compartments 18 and may be used exclusively to accommodate the turntable 5 when the turntable is moved out of the elevator shaft 17.
The side trays 52, 53 may be formed integrally with the movable center tray 51 at each side of the center tray 51. This structure moves the movable center tray 51 together with the side trays 52, 53.
A plurality of turning areas 8 may be provided. For example, in addition to the turning area 8 at basement level one in the first storage block 1, a similar turning section may be provided in any one of the storing sections 9, 10, 11 below basement level one.
The storage blocks need not be constructed underground but may be constructed above the ground.
The storing articles are not limited to cars 65. For example, the storing articles may be boxes or crates.
Platforms having forks are used to transfer the cars 65. However, pallets and prongs used to hold the pallets may be employed in the elevator 20. In this case, the pallet and the car 65 carried thereon correspond to the storing article. The car 65 is lifted and lowered by the prongs of the elevator 20 that hold the pallet. The storing article is transferred between the prongs of the elevator 20 and the turntable 56 or the movable tables 54, 55.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.
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A storage structure has an entry chamber for receiving articles, a storage area for storing the articles, a lift passage for connecting the entry chamber and the storage area, and a lift for conveying the articles through the lift passage between the entry chamber and the storage area. The storage structure includes a turning chamber provided separately from the entry chamber and connected to the lift passage for changing the orientation of an article. A turntable device is supported in the turning chamber to receive an article from the lift within the lift passage and to transfer an article to the lift. The turntable device includes a rotatable carrying surface and two auxiliary supports. One auxiliary support is located on each of two opposite sides of the turntable device for supporting the carrying surface when the carrying surface rotates. The carrying surface is movable between a position within the lift passage and a position outside of the lift passage.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 10/079,261 filed Feb. 21, 2002, now abandoned.
This application claims the priority of German Application No. 101 10 824.9 filed Mar. 7, 2001, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates to a device incorporated in a fiber processing machine such as a card, a cleaner, an opener or the like for cleaning, for example, cotton or chemical fibers. The fiber processing machine includes a rapidly rotating roll shrouded by a cover (composed of cover elements) provided with at least one air passage opening. The air passage opening is, at its downstream end as viewed in the direction of roll rotation, bordered by an air guiding element whose distance from the roll is variable.
In a known device the distance of the air guiding element from the roll is variable as a function of the removed quantities of waste such as trash, dust, fragments and the like.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved device of the above-outlined type.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the fiber processing machine includes a roll having a direction of rotation and a clothing for carrying thereon fiber material; a cover at least partially circumferentially shrouding the roll; an air passage opening provided in the cover; an air guiding element bordering the air passage opening; a support for movably holding the air guiding element for varying a distance between the roll and the air guiding element; a pressure sensor for measuring a static pressure between the cover and the roll; and an arrangement for setting a position of the air guiding element as a function of the pressure measured by the pressure sensor.
As a result of the measures according to the invention, an optimization of the working elements at the roll is feasible. In particular, an optimization at the separating elements, for example, separating knives is achieved with the aid of the air quantities and/or air stream, such as a pneumatic or a vacuum stream. It is a further advantage of the invention that in a simple manner additional air removal quantities and devices required therefor may be dispensed with because the air quantities exciting through air passage openings from regions where higher than atmospheric pressure (overpressure) prevails, may be introduced or drawn in through air passage openings provided in the vacuum zone.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevational view of a carding machine incorporating the invention.
FIG. 2 is a fragmentary schematic side elevational view of a carding cylinder and a doffer, showing an embodiment of an adjustable air intake opening.
FIG. 2 a is an enlarged detail of FIG. 2 .
FIG. 3 is a view similar to FIG. 2 a showing, in addition, a block diagram of a regulating device having a pressure sensor, a regulator and a setting member.
FIG. 4 is a schematic side elevational view of licker-ins of a carding machine, provided with pressure sensors, air passage openings and air guiding elements.
FIG. 5 is an enlarged detail of FIG. 4 .
FIG. 6 is a schematic side elevational view of a cleaner incorporating the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a carding machine CM which may be, for example, a high-performance DK 903 model, manufactured by Trützschler GmbH & Co. KG, Mönchengladbach, Germany. The carding machine CM has a feed roller 1 , a feed table 2 cooperating therewith, licker-ins 3 a , 3 b , 3 c , a main carding cylinder 4 rotating in the direction 4 b about the cylinder axis M, a doffer 5 , a stripping roll 6 , crushing rolls 7 , 8 , a web guiding element 9 , a web trumpet 10 , calender rolls 11 , 12 , a traveling flats assembly 13 having flat bars 14 , a coiler can 15 and a sliver coiler 16 .
Underneath the cylinder 4 , between the doffer 5 and the licker-in 3 c , a cylinder cover 17 is disposed which has two waste outlet openings 18 a and 18 b leading into respective suction chambers 19 a and 19 b . The waste outlet openings 18 a and 18 b are preceded—as viewed in the direction of rotation 4 b of the cylinder 4 —by an air inlet opening 21 a and an air outlet opening 21 b , respectively.
Turning to FIGS. 2 and 2 a , the cover 17 is composed of a plurality of cover elements 17 I , 17 II , 17 III . The waste outlet opening 18 a is preceded by the air inlet opening 21 a and a further air inlet opening 21 c . While a non-regulated air stream B enters from the atmosphere through the air inlet opening 21 a , an air stream C which enters through the air inlet opening 21 c is regulated. For this purpose an air guiding element 22 (air guiding vane) is provided which has a cylindrical bearing head 23 held in the cover part 17 II for rotation in the direction of the arrows E, F. The other end of the air guiding element 22 is oriented in the rotary direction 4 b of the cylinder 4 . By virtue of this arrangement the flow passage of the air inlet opening 21 c may be gradually widened or narrowed.
The air inlet opening 21 c is preceded by a pressure measuring element 24 with which the static air pressure underneath the cylinder cover 17 (that is, in the clearance b between the cover 17 and the cylinder clothing 4 a ) is measured. For this purpose a through bore is provided in the cover 17 . The pressure values are used for setting the distance a of the air guiding vane 22 from the points of the cylinder clothing 4 a . The setting of the position of the air guiding vane 22 may be effected manually in a manner not shown. Also, the position of the air guiding vane 22 may be, as shown in FIG. 3, automatically set as a function of the measured values of the pressure sensor 24 . For this purpose the pressure sensor 24 is associated with a transducer 25 which converts the pressure values into electric signals. The transducer 25 is connected to a regulator 26 (such as a microcomputer), having a desired value setter 27 . The regulator 26 is connected via a setting device, for example, a stepping motor, 28 with the air guiding element 22 . In the regulator 26 actual pressure values are compared with nominal pressure values and, in case of a deviation, signals representing such a deviation are applied to the motor 28 .
During operation, through the air inlet openings 21 a and 21 c , respective air streams B and C are drawn from the atmosphere by means of the vacuum prevailing in the gap between the cylinder cover 17 and the surface of the cylinder 4 . The air streams B and C impinge on the short fibers carried by the cylinder clothing 4 a and loosen the hold of the clothing 4 a on such short fibers. Thereafter, the short fibers are drawn through the waste outlet opening 18 a into the suction chamber 19 a and are removed via a conduit 36 which is coupled to a non-illustrated vacuum source. By means of the inflowing air streams B and C which exert a pressure on the short fibers and the vacuum stream D which exerts a pulling force on the short fibers, the removal force on the short fibers is greater than the retaining force of the cylinder clothing 4 a . In this manner, the short fibers are removed from the cylinder clothing to a greater extent than the long fibers still present on the cylinder clothing.
Turning to FIG. 4, the three licker-ins 3 a , 3 b and 3 c of a carding machine have a cover generally designated at 29 . The cover 29 is interrupted by air passage openings, by material transfer locations between two cooperating rolls, by air guiding elements 22 a - 22 g , separating knives 31 a , 31 b and stationary carding elements 30 a , 30 b . At various locations of the cover 29 pressure sensors 24 a - 24 g are provided. The pressure sensors 24 a - 24 g are connected to the regulating device 26 of FIG. 3 .
As shown in FIG. 5, the licker-in 3 a has a clothing formed of needles 3 I and rotating in the direction 3 1 , the licker-in 3 b has a relatively coarse sawtooth clothing 3 II and rotates in the direction 32 and the licker-in 3 c has a relatively fine sawtooth clothing 3 III and rotates in the direction 33 . The rapidly rotating licker-ins 3 a , 3 b and 3 c have an increasing circumferential velocity in the direction of material feed, that is, from the left to the right as viewed in FIG. 5 . At an air passage opening 121 provided in the cover 29 downstream of the stationary carding element 30 b as viewed in the direction of rotation of the roll 3 b , a vacuum prevails between the cover 29 and the roll clothing 3 II . At an air passage opening 21 II provided in the cover 29 upstream of the stationary carding element 30 b as viewed in the direction of rotation of the roll 3 b , an overpressure prevails between the cover 29 and the roll clothing 3 II . The pressure sensor 24 c provides for a measurement of the vacuum whereas the pressure sensor 24 d provides for a measurement of the overpressure. Between the air guiding element 22 d and the clothing 3 II a vacuum prevails whereas between the air guiding element 22 c and the clothing 3 II an overpressure is present. By virtue of the vacuum, air enters through the air passage opening 21 1 from the outside into the intermediate space between the cover 29 and the clothing 3 II whereas by virtue of the overpressure, air escapes outward through the air passage opening 21 II which is drawn away through the suction hood 19 a . In this manner the degree of separation of foreign particles such as trash and the like may be varied at the separating knives 31 a , 31 b.
Turning to FIG. 6, in a cleaning assembly which is disposed in a closed housing 37 and which may be a CVT 4 model manufactured by Trützschler GmbH & Co. KG, Monchengladbach, Germany, the fiber material to be cleaned, such as cotton, is supplied, as indicated by the arrow K, to the feed rollers 1 a , 1 b as fiber tufts. The feed rollers 1 a , 1 b clamp the fiber material and advance it to a pin roll 32 having a circumferential velocity of 10-21 m/sec. The pin roll 32 is followed by a sawtooth roll 33 which has a circumferential velocity of approximately 15-25 m/sec. The roll 33 is followed by additional sawtooth rolls 34 and 35 . The rolls 32 - 35 have a diameter of approximately 150-300 mm.
The roll 32 cooperates with a stationary carding element 30 I , a settable air guiding element 22 I , an air outlet opening 21 I , a separating knife 31 I and pressure sensors 24 a and 24 b.
The roll 33 cooperates with a stationary carding element 30 II , a settable air guiding element 22 III , an air outlet opening 21 III , a separating knife 31 III and a pressure sensor 24 d.
The roll 34 cooperates with a stationary carding element 30 IV , a settable air guiding element 22 IV , an air outlet opening 21 IV , a separating knife 31 IV and pressure sensors 24 e and 24 f.
The roll 35 cooperates with a stationary carding element 30 IV a settable air guiding element 22 IV an air outlet opening 21 IV , a separating knife 31 IV and a pressure sensor 24 h.
Respective suction hoods 19 I - 19 IV are associated with separating knives 31 I - 3 IV The working direction of the cleaner is designated at G. The pressure sensors 24 a - 24 h and the settable air guiding elements 22 I - 22 IV are connected to an electronic control and regulating device, for example, a microcomputer, as shown in FIG. 3 .
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A fiber processing machine includes a roll having a direction of rotation and a clothing for carrying thereon fiber material; a cover partially circumferentially shrouding the roll; an air passage opening provided in the cover; an air guiding element bordering the air passage opening; a support for movably holding the air guiding element for varying a distance between the roll and the air guiding element; a pressure sensor for measuring a static pressure between the cover and the roll; and an arrangement for setting a position of the air guiding element as a function of the pressure measured by the pressure sensor.
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PRIORITY CLAIM
This application claims priority to U.S. Provisional Patent Application Ser. No. 61/476,380 entitled: “ROBUST, RAPID, SECURE SAMPLE MANIPULATION BEFORE DURING AND AFTER IONIZATION FOR A SPECTROSCOPY SYSTEM”, inventor: Brian D. Musselman, and filed Apr. 18, 2011. This application is herein expressly incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention permits desorption ionization of powders, plant materials, and loose substances by securing the position of these materials which are otherwise easily displaced during sample handling and analysis.
BACKGROUND OF THE INVENTION
Ambient pressure desorption ionization sources, such as direct analysis in real time (DART®) and desorption electrospray ionization, enable detection of chemicals present as or embedded in a solid object or condensed on surfaces. Examples of sources include: using a flowing heated gas containing metastable atoms or molecules in DART, using a flowing gas containing ions and metastable atoms or molecules in Flowing Atmospheric Pressure Afterglow (FAPA), and using a flowing high pressure mixture of gas and solvent droplets in desorption electrospray ionization (DESI).
A common occurrence in Homeland Security associated ‘security alerts’ is the report describing the presence of a “white powder”. Identification of such materials requires a determination of composition. Enabling direct determination of composition without the requirement for dissolving the material facilitates reduced sample handling and thus affords greater protection to the humans undertaking the analysis as well as reduced time for analysis.
SUMMARY OF THE INVENTION
In various embodiments of the present invention, metal powders are used to disperse and retain samples for analysis. In an embodiment of the invention, a device for ionizing a sample comprises a sampler device for maintaining or constraining the position of the sample relative to the flowing gases and liquids exiting an ionization source. The device further includes a chamber or open region where the sample can be positioned and an entrance into a spectroscopy system where analysis occurs.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention is described with respect to specific embodiments thereof. Additional features can be appreciated from the Figures in which:
FIG. 1 shows a schematic diagram of a prior art sample device;
FIG. 2 shows a schematic diagram of a magnetically enabled sampling device according to an embodiment of the invention;
FIG. 3 shows a schematic diagram of the mixing chamber for sample preparation according to an embodiment of the invention;
FIG. 4 shows a schematic diagram of sample loading using a magnetically enabled sampling device as shown in the mixing chamber for sample preparation as shown in FIGS. 2 and 3 according to an embodiment of the invention;
FIG. 5 shows a schematic diagram of the photograph shown in FIG. 6 where sample loading using a magnetically enabled sampling device locates sample on three sites on a surface for analysis according to an embodiment of the invention;
FIG. 6 shows a photograph of sample loading which is using a magnetically enabled sampling device to locate a sample on three sites on a surface for analysis according to an embodiment of the invention;
FIG. 7 shows a schematic diagram of an off axis system of analysis enabled with a spectroscopy system as shown in the photograph of FIG. 11 according to an embodiment of the invention;
FIG. 8 shows a schematic diagram of the sampling device used to position a sample in a spectroscopy system according to an embodiment of the invention;
FIG. 9 shows a schematic diagram of the sampling device used to position multiple samples in a spectroscopy system according to an embodiment of the invention;
FIG. 10 shows a line drawing of an off axis system of analysis enabled with a spectroscopy system as shown in FIG. 11 ; and
FIG. 11 shows a photograph of the off axis system of analysis device enabled with a spectroscopy system according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The development of efficient desorption ionization sources for use with spectroscopy systems has enabled rapid analysis of samples without requiring laborious sample preparation. These desorption ionization sources require that the sample be positioned in a small region at the exit of the source to permit interaction of the ionizing gases with the sample for analysis.
Atmospheric pressure desorption ionization sources such as direct analysis real time (DART®) and desorption electrospray ionization function well for the ionization of solids and samples adsorbed onto surfaces because they can be fixed in position and not displaced by the action of the flowing gases and solvents. Once formed the ions can, for example, be introduced into a mass spectrometer for mass analysis. However, in the case of chemicals present in powder form, the direct desorption ionization analysis can become problematic due to displacement of the powder by the action of the flowing gases and liquids utilized in the experiment. Without retention of the sample in the desorption ionization region, analysis of these compounds is either compromised and/or results in contamination of the spectroscopy system as the desorbed chemicals contaminate surfaces and entrances to the spectroscopy system.
Thus, for loose powders the utility of the desorption ionization technology is reduced since powders and other light weight or loose samples often cannot be anchored without altering their chemical state (e.g., making into a solution). In an embodiment of the present invention, a simple method to retain powder type samples for surface desorption ionization at atmospheric pressure with increased certainty, involves the co-mixing and thereby the dispersal of a heavy weight powder with the sample powder prior to analysis in order to secure the powder in position. In an embodiment of the present invention, the heavy weight powder can be a metal powder. In an embodiment of the invention, the sample with the metal powder dispersed and therefore coating the sample can be maintained in its position by the weight of the metal powder. In an alternative embodiment of the present invention, the sample with the metal powder dispersed and thereby coating the sample can be maintained in its position by a magnetic field used to fix the metal in position for analysis. In an embodiment of the present invention, a device provides the means for positioning of a sample powder in a desorption ionization region.
In various embodiments of the invention, the metal powder or granules can be selected from the group consisting of metals and non-metals. In various embodiments of the invention, the powder or granules can be selected from the group consisting of magnetic and non-magnetic metals. In various embodiments of the invention, the powder or granules can be one or both a paramagnetic and a ferromagnetic material.
Paramagnetism is a form of magnetism which occurs only in the presence of an externally applied magnetic field. Ferromagnetism is the mechanism by which certain materials form permanent magnets or are attracted to magnets. Classical electro-magnetism indicates that two nearby magnetic dipoles will tend to align in opposite directions, so their magnetic fields will oppose one another and cancel out. However, in ferromagnetic materials the dipoles tend to align in the same direction. The Pauli Exclusion Principle teaches that two electrons with the same spin cannot also have the same ‘position’. Under certain conditions, the Pauli Exclusion Principle can be satisfied if the position of the outer orbitals of the aligned electrons is sufficiently distant. In these ferromagnetic materials, the electrons having parallel spins result in the distribution of electric charge in space being further apart and therefore the energy of these systems is at a minimum. The unpaired electrons align in parallel to an external magnetic field in paramagnetic materials. Only atoms with partially filled shells can have a net magnetic moment, so ferromagnetism and paramagnetism only occur in materials with partially filled outer electron shells. Non-magnetic metals typically have filled outer electron shells (e.g., Beryllium, Cadmium, Calcium, Magnesium, Mercury, and Zinc) or form covalently bound molecules fulfilling this condition (e.g., Aluminum, Barium, Copper, Gold, Lead, Lithium, Platinum, Potassium, Radium, Rhodium, Strontium, Silver, Tin, Titanium and Tungsten). As the temperature of ferromagnetic materials increase, the entropy of the system reduces the ferromagnetic alignment of the dipoles. When the temperature rises above the Curie temperature, the system can no longer maintain spontaneous magnetization, although the material still responds paramagnetically to an external field (see Table I for list of ferromagnetic and ferrimagnetic materials and their Curie temperature).
TABLE I
List of ferromagnetic and ferrimagnetic materials and their
Curie temperature
Material
Curie temperature (° K)
Co
1388
Fe
1043
FeOFe 2 O 3
858
NiOFe 2 O 3
858
CuOFe 2 O 3
728
MgOFe 2 O 3
713
MnBi
630
Ni
627
MnSb
587
MnOFe 2 O 3
573
Y 3 Fe 5 O 12
560
CrO 2
386
MnAs
318
Gd
292
Dy
88
EuO
69
In various embodiments of the invention, the powder or granules can be selected from the group consisting of one or more iron containing substances including Fe, FeO, FeOFe 2 O 3 , Fe 2 O 3 , MnOFe 2 O 3 , MgOFe 2 O 3 , Y 3 Fe 5 O 12 and Fe 3 O 4 . In various embodiments of the invention, the powder or granules can be selected from the group consisting of one or more copper containing substances including Cu, CuO, CuoFe 2 O 3 and Cu 2 O. In various embodiments of the invention, the powder or granules can be selected from the group consisting of one or more aluminum containing substances including Al and Al 2 O 3 . In various embodiments of the invention, the powder or granules can be selected from the group consisting of one or more nickel containing substances including Ni, NiO, Ni 2 O 3 , Ni(OH) 2 and NiOFe 2 O 3 . In various embodiments of the invention, the powder or granules can be selected from the group consisting of one or more cobalt containing substances including Co, NaCoO 2 and Co 3 O 4 . In various embodiments of the invention, the powder or granules can be selected from the group consisting of one or more lanthanide metals. In various embodiments of the invention, the powder or granules can be selected from the group consisting of one or more ferromagnetic and/or ferrimagnetic materials of Table I. In various embodiments of the invention, the powder or granules can be selected from the group consisting of physical mixing of two or more of Fe, FeO, FeOFe 2 O 3 , Fe 2 O 3 , Fe 3 O 4 , Cu, CuO, and Cu 2 O, Al and Al 2 O 3 . In various embodiments of the invention, the powder or granules can be selected from a physical combination of two or more metals or alloys that can either be magnetic or non-magnetic.
When a security alert reports the presence of a “white powder” or other unknown substance, there is an immediate and real need for determining the composition of the powder and specifically whether the powder is anthrax or any other dangerous biological or chemical agent. The first step in analysis of these ‘unknowns’ often involves isolation of the material in specialized containers for transfer to protect the analyst and his or her environment from contamination. In order to determine the chemical composition or organism present in the powder, the analyst often creates a soluble solution by dissolving the powder in water or an appropriate solvent. The use of expensive and often elaborate testing equipment is needed when using such a soluble solution and since not all powders are soluble valuable time is lost as the analyst labors to create that solution. Ultimately, the sample represents no security threat but the time used in determination of its composition is lengthened by each step of manipulation.
The challenge to rapid chemical analysis is designing a process that uses a minimum of sample manipulation in order to complete chemical analysis in mere seconds. The ability to complete rapid analysis of the sample can be facilitated if real time ionization can be used as a screening method. Thus, the development of a more practical device for positioning samples with minimal human intervention can be an important requirement for deploying real time monitoring, beyond the confines of the laboratory. Utilizing metal powders with ionization techniques to sample and retain the ‘unknown’ powder and subsequently permit its positioning for analysis can provide a means to facilitate the rapid determination of composition which is necessary to either dismiss or elevate the threat level.
A vacuum of atmospheric pressure is 1 atmosphere=760 torr. Generally, ‘approximately’ in this pressure range encompasses a range of pressures from below 10 1 atmosphere=7.6×10 3 torr to 10 −1 atmosphere=7.6×10 1 torr. A vacuum of below 10 −3 torr would constitute a high vacuum. Generally, ‘approximately’ in this pressure range encompasses a range of pressures from below 5×10 −3 torr to 5×10 −6 torr. A vacuum of below 10 −6 torr would constitute a very high vacuum. Generally, ‘approximately’ in this pressure range encompasses a range of pressures from below 5×10 −6 torr to 5×10 −9 torr. In the following, the phrase ‘high vacuum’ encompasses high vacuum and very high vacuum. The sampler/chamber system can be at atmospheric pressure.
Movement of Samples into and Through the Ionization Region for Analysis
In atmospheric pressure desorption ionization experiments solid objects placed in close proximity to the exit of the source interact with the gas exiting that source. The solid object is often positioned manually or by using devices such as tweezers. In an embodiment of the present invention, a sample in powder form can be immersed into or deposited into a container for co-mixing with metal powder. After mixing to disperse the powder in with the metal, a small fraction of the sample can be removed from the tube along with the metal, enabling its analysis as it is placed in the desorption ionization region. For rapid qualitative determination of samples, the quantity of sample retained on the metal is not critical; therefore, the acquisition of even a small quantity of material can enable a successful analysis. In an alternative embodiment of the present invention, automation of the sampling technology for desorption ionization involves fabrication of a partially glass and partially metal rod sampler tip to which a small magnet can be fixed to cause the magnetized metal coated with “unknown” powder to be retained in its position for analysis. In another embodiment of the invention, by using a microscope slide-sized flat surface (i.e. a flat surface the size of a microscope slide) to which one or more magnets have been fixed on the underside, the metal coated with powder can be deposited on the surface for analysis. In a variety of embodiments of the invention, electro-magnetic fields can be used to automate the movement of the sample from container to container or from container to sample surface for analysis. In an embodiment of the invention, a non-magnetic metal coated with powder can be deposited onto a surface for analysis where the weight of the metal can be sufficient to cause the sample to maintain position in the presence of the flowing gas stream used for desorption ionization.
In an embodiment of the present invention, the mixing of a metal powder with an ‘unknown’ powder or ‘unknown’ sample present in crystalline form facilitates mechanical control of the positioning of the sample with magnetic or electro-magnetic fields. A ‘sampler device’ can be fabricated such that the sample can be inserted into an enclosed chamber attached to a desorption ionization region. Using the ‘sampler device’ the sample can be reliably transferred from the enclosed chamber into the desorption ionization region by mechanical or electro-mechanical means. In an embodiment of the invention a method is described for depositing the ‘unknown’ or material of interest onto a sampler and dropping the sampler into the chamber and subsequently manipulating the sampler into position using robotics without requiring human intervention to physically touch or contact the sample. Once the sample is placed in the desorption ionization region, chemical analysis can take place.
A mechanical device is operated by a mechanism. An electro-mechanical device or system is a mechanical device or system that is actuated or controlled by electricity. An electro-magnetic device is operated, actuated or controlled by magnetism produced by electricity. An electro-mechanical force is a force formed by electro-magnetic induction.
Sampler Device
FIG. 1 shows prior art of a desorption ionization source coupled to a mass spectrometer. In FIG. 1 , the ‘sampler device’ 116 is a 1.4 mm outside diameter, 0.5 mm inside diameter by 6 mm long glass tube with one end sealed. The sampler device has a coating of material on its exterior surface at the closed end. The coating was generated by dissolving the sample in a solvent and then applying a solution to the sampler device 116 . The device 116 is positioned between the ionization source 101 which is directing a flow of gas or liquid at the device 116 . Materials desorbed from the surface are ionized and those products enter the spectrometer through an atmospheric pressure inlet 121 . In various embodiments of the invention, as shown in FIG. 2 , one or more small magnets or pieces of either paramagnetic or ferromagnetic susceptible metal 234 are secured to a metal rod 216 having similar dimensions to the glass rod of FIG. 1 . The device 216 can be positioned between the ionization source 201 which is directing a flow of gas or liquid at the device 216 . Materials desorbed from the surface can be ionized and those products can enter the spectrometer through an atmospheric pressure inlet 221 . A sample of magnetic susceptible metal powder or granules co-mixed with sample powder can then be applied to the closed-end of the tube of the sampler. Preparation of the sample for analysis is depicted in FIG. 3 where a powder sample 341 represented on a common laboratory spatula 356 is added to a container 318 containing an excess of metal 307 . As shown in FIG. 4 after mixing of the sample with the metal powder in the container, the metal sampler device 416 to which one or more small magnets or pieces of magnetic susceptible metal 434 have been secured can be inserted into the volume of the container 418 containing an excess of metal powder coated with the sample 407 to permit collection of a portion of the metal powder coated with sample 447 . In an embodiment of the invention shown in FIG. 5 the sampler device 516 is a small magnetically susceptible piece of metal such as an iron nail to which a small magnet 534 has been positioned approximately one (1) inch above the closed end of the nail 516 , referred to as a ‘magnetized nail’ 516 . The magnetized nail 516 can be used as a sample transfer device to move sample from the container 418 shown in FIG. 4 to a surface for sampling. In FIG. 5 sample positioning of sample (mixed with metal powder 547 ) for analysis is facilitated by using a surface 553 under which a small magnet 537 or series of magnets can be placed in order to retain the magnetically susceptible metal powder coated with sample in position for analysis. A photograph of the device described in FIG. 5 is shown in FIG. 6 . Implementation of the device of FIG. 5 with a direct analysis in real time ionization source is shown schematically in FIG. 7 . FIG. 7 shows the surface 753 with magnet 737 positioned to locate sample positioned between the ionization source 701 which is directing a flow of gas or liquid at the sample. Materials desorbed from the surface are ionized and those products enter the spectrometer through an atmospheric pressure inlet 721 . A line drawing of the device of FIG. 7 with a direct analysis in real time ionization source is shown in FIG. 10 . A photograph of the device described in FIG. 7 is shown in FIG. 11 . In an embodiment of the invention shown in FIG. 8 , the end of the metal powder coated sample device 816 (utilizing a magnet 834 to hold the sample) can be positioned inside a sampling chamber 836 to allow sampling in a closed volume to protect the analyst from harmful chemicals and toxins. The end of the sampling device 816 can be positioned between the ionization source 801 , which can be directing a flow of gas or liquid at the device 816 . Materials desorbed from the surface can be ionized and those products enter the spectrometer through an atmospheric pressure inlet 821 . In an embodiment of the invention shown in FIG. 9 , the sampler device 953 can be inserted through port 924 and positioned inside a sampling chamber 936 to allow sampling in a closed volume to protect the analyst from harmful chemicals and toxins. The sampler device 953 can be positioned between the ionization source 901 which can be directing a flow of gas or liquid at the sampler device 953 . Materials desorbed from the surface can be ionized and those products can enter the spectrometer through an atmospheric pressure inlet 921 . Orientation of the sampler device 953 can be manipulated without concern for loss of sample since the action of the magnetic field derived from the small magnets 937 retains the sample on the surface. Once analysis is complete the sampler device 953 can exit the chamber 936 through port 939 . The sample can be manipulated in the closed environment to permit analysis.
Electro-Mechanical Chamber
In an embodiment of the present invention, the ‘electro-mechanical chamber’ can be a cylinder having an opening through which the sampler can be inserted. The open ‘electro-mechanical chamber’ can be of sufficient dimension to permit insertion of a variety of objects. In an embodiment of the present invention, the open ‘electro-mechanical chamber’ can accept 1×10 −4 m diameter tubes. In an alternative embodiment of the present invention, the open ‘electro-mechanical chamber’ can accept 1×10 −3 m diameter tubes. In another embodiment of the present invention, the open ‘electro-mechanical chamber’ can accept 1×10 −2 m diameter tubes. In another alternative embodiment of the present invention, the open ‘electro-mechanical chamber’ can accept 1×10 −1 m diameter tubes. In various embodiment of the present invention, the open ‘electro-mechanical chamber’ can accept a non-cylindrical sampler device.
In an embodiment of the invention shown in FIG. 7 a sampler with the configuration shown in FIG. 5 can be depicted as a plate 753 with the ionization gun 701 directing species at the sample which forms ions that enter the spectrometer through aperture 721 . As shown in FIG. 10 the sampler with the configuration shown in FIG. 5 is depicted as a rectangular plate 1053 with the sample mixed with metal powder 1057 has been deposited, with the ionization gun 1001 directing species at the sample which forms ions that enter the spectrometer through aperture 1021 . The location of the sample mixed with metal powder 1057 in front of the ionization gun 1001 can be changed using a location locking device 1024 . The rectangular plate 1053 enters the proximal end of the ‘electro-mechanical chamber. FIG. 9 illustrates a series of events starting with capture of the ‘sampler device’ 953 in a fixed position such that the sample itself does not touch any surface of the ‘electro-mechanical chamber’. The sample may be pushed through an entrance 924 and exit 939 of the chamber to permit rapid, safe detection of powder with the spectroscopy system 921 . In an embodiment of the invention, a series of magnets to which a magnetically susceptible metal coated powder of interest can be positioned along a conveyor belt serves to transfer the powder coated metal to the desorption ionization region by using an electro-magnetic field. The interaction of the sample coated magnet with the electro-magnet element serves to hold the sampler in an intermediate position prior to analysis. A sampling zone 901 , where the analysis occurs, can be at the distal end of the ‘electro-mechanical chamber’ of the desorption ionization source. At the proximal end of the ‘electro-mechanical chamber a lid capable of closing and forming an airtight seal once the sampler had been placed inside the ‘electro-mechanical chamber’ in a fixed position. The function of the lid can be to maintain enough pressure to keep gases from escaping through the proximal end of the cylindrical ‘electro-mechanical chamber’. Closure of the lid can also initiate the sampling sequence by depressing a switch or completing an electrical or optical contact, and thus connecting an initiation event marker of electrical, digital or mechanical design.
In an embodiment of the invention with the ‘electro-mechanical chamber’ containing the ‘sampler device’ closed and sealed, the composition of the chemical environment surrounding the sample can be controlled. In an embodiment of the invention, the sealed ‘electro-mechanical chamber’ can be used to support one or more functions selected from the group consisting of atmospheric pressure chemical ionization; negative ion chemical ionization; prevention of oxidation or reduction of the sample; or exposure of the sample to one or more other ionization sources. With the sampler under the influence of the electro-magnetic field, the sample can be positioned for desorption ionization. In the case where the sample is a large object with one or more distinct surfaces, the electro-magnetic field can be used to move the entire object in order to affect desorption of different areas of the sample by use of the electro-magnetic fields. In the case where the sample requires different ionization conditions using the same ionization source, the electro-magnetic field can be used to move the entire object in order to affect desorption of the same area of the sample with similar DART guns operated at different conditions by use of the electro-magnetic fields.
In an embodiment of the invention, after the analysis is complete and to facilitate analysis of the next sample, the electro-magnetic field can be used to expel the ‘sampler device’ out from the ionization region from the ‘electro-mechanical chamber’. Once the analysis is complete, the electro-magnetic field can either be turned off and a spring mechanism used to release the sampler device, or the electro-magnetic field can be reversed. In an embodiment of the invention, the opening of an exit port door located at the distal end of the ‘electro-mechanical chamber’ can deactivate the electro-magnetic field elements and release the sampler device allowing the sample to fall under the effect of gravity through the exit port located at the distal end of the ‘electro-mechanical chamber’.
In another embodiment of the invention, a series of electro-magnetic devices including rings, plates, balls, or other shapes designed to capture specific objects can be used to transport the sample into the ideal position for desorption ionization. Once the analysis is complete, the series of electro-magnetic rings can be used to eject the ‘sampler device’ back into the ‘electro-mechanical chamber’. In another embodiment of the invention, concerted action of the electro-magnetic fields results in a high throughput apparatus for rapid sampling by desorption ionization at atmospheric pressure.
The sampler device can have a segment of metal comprised of a band of metal or a strip of metal positioned remote from the desorption ionization region. In this manner, the magnetic fields would not deflect or defocus ions that must be transferred to the spectroscopy system for analysis. In an embodiment of the invention the metal or magnets can be enclosed in the body of the sampler at a position remote from the desorption ionization region. The ‘sampling device’ objects can be made of glass, ceramic, plastic, wood, fabric or other suitable material shaped into tubes, rod, plates, or other objects customized for sampling. The metal pin, crimping cap, shank, brad, staple, wire or band can be inserted into or bonded to the sampling device in order to secure that sample to the sampling object.
The ‘sampler device’ and the ‘electro-mechanical chamber’ system can be automatically operated at increased sample turnaround speed without requiring an analyst or other human intervention. A significant utility of the sampler/chamber system embodied in the invention lies in unattended operation which thereby increases sampling speed.
In an embodiment of the invention a device for ionizing an analyte comprises a chamber with at least three ports, where a first port allows the analyte to enter the chamber and the chamber is adapted to mix the analyte with a material using a magnetic field source where the magnetic field source is adapted to constrain the analyte mixed with the material within the chamber. The device further comprises an atmospheric pressure ionization source adapted to be directed at the analyte mixed with the material to form analyte ions which exit out of a second port. The magnetic field source is further adapted to remove the analyte mixed with the material from the chamber through a third port to dispose of the analyte.
In an embodiment of the invention a method of ionizing a sample comprises mixing the sample with a ferromagnetic material with a lower ionization efficiency relative to the sample and constraining the sample mixed with the material using a magnetic field and generating one or more analyte ions of the sample and then using the magnetic field to dispose of the sample.
In an embodiment of the invention a kit for handling a sample for atmospheric pressure ionization comprises a vial adapted to be opened and resealed containing a material, where opening the vial and locating the sample in the vial and resealing the vial mixes the sample and the material. The kit further comprises a probe including a proximal end, a distal end, a coil situated at the distal end and a switch, where the switch is adapted to apply or discontinue an electro-magnetic field through the coil to position the material mixed with the sample onto the probe, where the probe is adapted to enter the vial and thereby position the material mixed with the sample onto the probe for removal from the vial. The kit further comprises an analysis plate with one or both a fixed magnet and an electro-magnet adapted to move the material mixed with the sample from the probe onto the analysis plate while constraining the material mixed with the sample to one or more regions on the plate for atmospheric pressure ionization.
Example embodiments of the methods, systems, and components of the present invention have been described herein. As noted elsewhere, these example embodiments have been described for illustrative purposes only, and are not limiting. Other embodiments are possible and are covered by the invention. Such embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. For example, it is envisaged that, irrespective of the actual shape depicted in the various Figures and embodiments described above, the outer diameter exit of the inlet tube can be tapered or non-tapered and the outer diameter entrance of the outlet tube can be tapered or non-tapered.
Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
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This invention provides for the efficient positioning of a sample to be analyzed by using either magnetic or electro-mechanical fields to retain the sample in the ionization region. In an embodiment of the present invention, the sample is contacted with a sampler device, which is inserted into a chamber and accurately positioned using electro-mechanical devices. In an embodiment of the invention, the influence of an electro-mechanical field on the sampler device enables the sample to be positioned in the ionization region to be contacted by particles that result in ionization of the sample whereby rendering the resulting ions available for analysis.
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FIELD OF THE INVENTION
The present invention relates to a method for producing polyether-polyol having a narrow molecular weight distribution by controlling a molecular weight distribution of polyether-polyol having tetrahydrofuran units which is produced through polymerization of tetrahydrofuran or copolymerization of tetrahydrofuran with any other cyclic ether. The polyether-polyol having tetrahydrofuran units exhibits good elasticity properties, low-temperature properties and hydrolysis resistance in polyurethane elastic fibers, polyurethane elastomers, polyether-polyester elastomers and polyurethane-containing elastic paints, and it is an extremely useful substance in the field of chemical industry.
BACKGROUND OF THE INVENTION
Generally, an ordinary polyether-polyol produced by cationic polymerization such as polymerization of tetrahydrofuran or copolymerization of tetrahydrofuran with any other cyclic ether has a broad molecular weight distribution. However, it is known that, when a polyether-polyol having a narrow molecular weight distribution is used for the production of polyurethane elastic fibers, polyether-ester elastomers and the like, the products may have well-balanced physical properties as compared with those from the polymer having a broad molecular weight distribution, and the products may accurately exhibit their properties in accordance with the object thereof and, in addition, there can be produced good elastomers having improved heat resistance, especially excellent dynamic physical properties such as elongation recovery and repetitive compression resistance. On the contrary, for example, polytetramethylene ether glycol obtained through polymerization of tetrahydrofuran by the use of a typical catalyst, fluorosulfonic acid, chlorosulfonic acid or acetic anhydride-perchloric acid has a broad molecular weight distribution, since the polymerization mode for it is cationic polymerization. In addition, its molecular weight distribution does not follow the rule of Gauss distribution but is biased toward the high-molecular fraction. The broad molecular weight distribution of the polymer is a long-pending question in the art. In particular, with the recent tendency toward precision industries, the request for polyether-polyol with a narrow molecular weight distribution is increasing (e.g., see JP-B 57-47687, the term “JP-B” used herein means an “examined Japanese Patent Publication”).
It has heretofore been well known that a polydisperse polymer produced through an ordinary polymerization may be fractionated into a monodisperse polymer through an ordinary liquid-liquid fractionation in a combination of an oleophilic or non-polar solvent and a hydrophilic or polar solvent. The fractionation of polyoxypropylene glycol, polyoxyethylene glycol and polytetramethylene ether glycol in cyclohexane-toluene/water-methanol with varying the ratio of water-methanol therein gives polymers of almost monodispersion (e.g., see Makromol. Chem., 41, 61 (1960) and J. Appl. Poly. Sci., 9, 467 (1965)). Also, a method of fractionating tetrahydrofuran polymer or tetrahydrofuran-alkylene oxide copolymer in cycloalkane/water-methanol is disclosed (e.g., Japanese Patent 3,352,702).
However, even though polyoxytetramethylene glycol having a narrow molecular weight could be obtained in these methods in which some organic solvents are used in combination thereof, there are still problems in that much energy is needed for solvent recovery and solvent separation may be often difficult. Still another but more serious problem is that the residual fraction that remains after the fractional extraction of the intended product having a narrow molecular weight distribution must be subjected to post treatment. Anyhow, these methods have the industrial disadvantages as above.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method for producing polyether-polyol having a narrow molecular weight distribution by controlling the molecular weight distribution of polyether-polyol. More precisely, it provides a method for producing polyether-polyol having a narrow molecular weight distribution by controlling the molecular weight distribution of a polyether-polyol containing tetrahydrofuran units which is produced through polymerization of tetrahydrofuran or copolymerization of tetrahydrofuran with any other cyclic ether, in particular to a industrially advantageous method for producing polyether-polyol having a narrow molecular weight distribution by narrowing the molecular weight distribution of the polymer.
As a result of extensive investigation, the present inventors have found an industrially advantageous a method for producing polyether-polyol having a narrow molecular weight distribution by controlling the molecular weight distribution of a polyether-polyol containing tetrahydrofuran units which is produced through polymerization of tetrahydrofuran or copolymerization of tetrahydrofuran with any other cyclic ether, especially a method for producing polyether-polyol having a narrow molecular weight distribution by narrowing the molecular weight distribution of the polymer. The present, invention has been completed based on this finding.
That is, the present invention provides a method for producing a polyether-polyol having a narrow molecular weight distribution, which comprises carrying out selective fractional extraction of the low-molecular weight component from a polyether-polyol (A) having an average molecular weight of from 500 to 4500 represented by formula (1):
HO—[(CH 2 ) 4 O] n —[(CR 1 R 2 ) p O] q —H (1)
wherein R 1 and R 2 , which may be the same or different, each represents a hydrogen atom or a linear or branched alkyl group having from 1 to 5 carbon atoms; n indicates a positive integer; p indicates an integer of from 1 to 8; and q indicates 0 or a positive integer, by suitably determining the amount of the aqueous sulfuric acid solution to the overall organic layer and the sulfuric acid concentration in accordance with the molecular weight and molecular weight distribution of the desired polyether-polyol by the use of an aqueous solution (C) containing from 15 to 70 wt % sulfuric acid at a room temperature to 100° C.
Further, the present invention relates to the following embodiments:
The above-mentioned method for producing a polyether-polyol having a narrow molecular weight distribution, wherein the selective fractional extraction is carried out in the presence of a fractional extraction solvent (B) which dissolves the polyether-polyol (A).
The above-mentioned method for producing a polyether-polyol having a narrow molecular weight distribution, wherein the fractional extraction solvent (B) is tetrahydrofuran or alkyl-substituted tetrahydrofuran or a mixture thereof.
The above-mentioned method for producing a polyether-polyol having a narrow molecular weight distribution, wherein the amount of the fractional extraction solvent (B) is 0.2 to 4.0 wt % based on the polyether-polyol (A).
The above-mentioned method for producing a polyether-polyol having a narrow molecular weight distribution, wherein the sulfuric acid concentration of the sulfuric acid-containing aqueous solution is from 20 to 60 wt %.
The above-mentioned method for producing a polyether-polyol having a narrow molecular weight distribution, wherein the fractional extraction temperature is from a room temperature to a boiling point of the fractional extraction solvent (B).
The above-mentioned method for producing a polyether-polyol having a narrow molecular weight distribution, wherein the fractional extraction temperature is a boiling point of the fractional extraction solvent (B).
The above-mentioned method for producing a polyether-polyol having a narrow molecular weight distribution, wherein the fractional extraction treatment is carried out by the use of the unreacted monomer of tetrahydrofuran or alkyl-substituted tetrahydrofuran still remaining in the reaction mixture after polymerization or copolymerization, directly for the fractional extraction solvent.
The above-mentioned method for producing a polyether-polyol having a narrow molecular weight distribution, wherein sulfuric acid that is formed from a sulfuric acid-based catalyst of, a cationic polymerization catalyst, through degradation thereof with water added for polymerization termination is directly used for the sulfuric acid-containing aqueous solution for the fractional extraction treatment.
The above-mentioned method for producing polyether-polyol having a narrow molecular weight distribution, the sulfuric acid-based catalyst of a cationic polymerization catalyst is one or more selected from fluorosulfonic acid, chlorosulfonic acid and fuming sulfuric acid.
The above-mentioned method for producing a polyether-polyol having a narrow molecular weight distribution, wherein the fractional extraction treatment is carried out in a reaction tank used for the synthesis of the polyester-polyol (A) or a separatory tank used for the recovery of the aqueous sulfuric acid solution after the reaction.
The above-mentioned method for producing polyether-polyol having a narrow molecular weight distribution, which further adding water and/or an alkali substance to an aqueous sulfuric acid solution (D) containing a low-molecular weight component of the polyether-polyol obtained after the selective fractional extraction of the low-molecular weight component by the use of an aqueous solution (C) containing sulfuric acid to thereby reduce the sulfuric acid concentration of the aqueous sulfuric acid solution (D) containing a low-molecular weight component, carrying out selective fractional extraction of the low-molecular weight component in the aqueous sulfuric acid solution (D) at a room temperature to 100° C. to recover a polyether-polyol, wherein the amount of the water and/or alkali substance added to an aqueous sulfuric acid solution (D) is suitably determined in accordance with the molecular weight and molecular weight distribution of the intended polyether-polyol to be fractionally extracted.
The above-mentioned method for producing a polyether-polyol having a narrow molecular weight distribution, wherein the recovery treatment is carried out in the presence of a fractional extraction solvent (B) which dissolves the polyether-polyol.
The above-mentioned method for producing a polyether-polyol having a narrow molecular weight distribution, wherein the fractional extraction solvent (B) is tetrahydrofuran or alkyl-substituted tetrahydrofuran or a mixture thereof.
The above-mentioned method for producing a polyether-polyol having a narrow molecular weight distribution, which includes a step of heating and distilling the sulfuric acid-containing aqueous layer after the fractional extraction treatment to thereby make the low-molecular weight fraction existing in the sulfuric acid-containing aqueous layer depolymerized into monomer by an acid, and evaporating and recovering the resulting monomer along with the unreacted monomer dissolved in the sulfuric acid-containing aqueous layer.
The low-molecular weight fraction dissolved in the sulfuric acid-containing aqueous layer can be obtained as a low-molecular weight polyether-polyol by adding further water and/or alkali substance to the sulfuric acid-containing aqueous layer and repeatedly carrying out the fractional extraction operation, followed by recovering and purifying it.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows GPC curves of each polytetramethylene ether glycol obtained in Examples 1 to 3 by means of GPC analysis, in which the vertical axis indicates the relative concentration of the polymer. The full line is the molecular weight distribution curve of the starting polytetramethylene ether glycol used in the Examples, i.e., the polymer before molecular weight distribution control, and the dotted lines are the molecular weight distribution curves of polytetramethylene ether glycol obtained in Examples 1 to 3.
DETAILED DESCRIPTION OF THE INVENTION
The polyether-polyol to be processed according to the method of the invention may be a pure or crude product, having an industrially useful average molecular weight of from 500 to 4500. The fractionation solvent is a solvent for solving the polyether-polyol, preferably tetrahydrofuran, alkyl-substituted tetrahydrofuran or their mixture. The amount of the fractionation solvent used in the present invention is preferably from about 0.2 to 4.0 in terms of the ratio by weight to the polyether-polyol, but as mentioned hereinabove, the unreacted monomer may be used directly for the solvent.
The tetrahydrofuran or alkyl-substituted tetrahydrofuran used as a solvent in the method of the present invention is a monomer for the intended polyether-polyol product in the present invention, and therefore the unreacted monomer after the polymerization to give the polymer may be used directly for the fractionation solvent, and after the intended fractionation operation, it may be recovered and purified, and then may be used again for the monomer. On the other hand, the sulfuric acid-containing aqueous layer used for the extraction contains the extracted low-molecular fraction and the unreacted monomer, and when this is heated and distilled, then the polyether-polyol dissolved therein may be depolymerized by the acid and the resulting monomer may be recovered along with the dissolved monomer. The recovered monomer may be purified and may be used again. The remaining, sulfuric acid-containing aqueous layer may be used again as the next fractionation solvent.
The sulfuric acid concentration of the sulfuric acid-containing aqueous solution used for the fractional extraction in the method of the present invention is from 15 to 70 wt %, but preferably from 20 to 60 wt %. If the sulfuric acid concentration is 15 wt % or less, the extraction ratio of the low-molecular fraction is low; but if it is 70 wt % or more, then polyether-polyol, tetrahydrofuran or alkyl-substituted tetrahydrofuran and aqueous sulfuric acid solution mutually dissolve and the fractional extraction is difficult. Within the sulfuric acid concentration of from 15 to 70 wt %, the higher sulfuric acid concentration increases the low-molecular fraction extraction ratio. Accordingly, the intended polyether-polyol having a narrow molecular weight distribution can be obtained, and when the sulfuric acid concentration is varied within the defined range, then the polyether-polyol having a desired molecular weight distribution in accordance with the object thereof can be obtained in any desired manner.
The amount of the aqueous sulfuric acid solution to the overall organic layer may be suitably determined in accordance with the sulfuric acid concentration and the molecular weight and molecular weight distribution of the intended polyether-polyol to be fractionally extracted. Regarding the aqueous sulfuric acid solution, when the method of the present invention is applied to polyether-polyol or its product obtained by the use of a cationic polymerization catalyst not containing sulfuric acid, then a separately prepared, aqueous sulfuric acid solution is used and circulated, but when it is applied to polyether-polyol obtained by the use of a typical sulfuric acid-based cationic polymerization catalyst such as fluorosulfonic acid, chlorosulfonic acid or fuming sulfuric acid, or other sulfuric acid-based catalyst that consists essentially of any of these, then sulfuric acid that is derived from the catalyst through degradation thereof with water added after polymerization termination may be used directly as it is. Accordingly, the fractional extraction operation may be carried out in a reaction tank of the polyether-polyol or a separatory tank for the recovery of the aqueous sulfuric acid solution after the reaction.
The fractional extraction in the method of the present invention is effected by stirring the system at a predetermined temperature until the overall organic layer and the aqueous sulfuric acid layer can entirely reach the fractionation equilibrium, and then statically leaving it for liquid-liquid separation. The temperature may be from a room temperature to 100° C., preferably from a room temperature to around the boiling point of a fractional extraction solvent such as tetrahydrofuran, alkyl-substituted tetrahydrofuran or their mixture, more preferably around the boiling point thereof for shortening the time for static liquid-liquid separation.
The molecular weight distribution is defined as a ratio of “weight-average molecular weight” to “number-average molecular weight”, but it is known that the approximate value of the molecular weight distribution of the polyether-polyol may be obtained from the measured data of the bulk viscosity and the number-average molecular weight of the polymer (see JP-B-57-47687, the text of which is incorporated herein by reference). That is, the bulk viscosity can be measured according to a known method, and the number-average molecular weight can be obtained from the hydroxyl value (mg KOH/g) of the polymer measured in a known method. The approximate molecular weight distribution can be obtained from a ratio of “viscosity-average molecular weight” to “number-average molecular weight”. The viscosity-average molecular weight (Mvis) is calculated according to the following equation that relates to the bulk viscosity (poise) measured at 40° C.
M vis=anti-log(0.493 log-viscosity+3.0646).
This shows that the polymer having a larger ratio of viscosity-average molecular weight (Mvis) to number-average molecular weight (Mn) has a broader molecular weight distribution.
The present invention will now be illustrated in greater detail with reference to the Examples in view of the Comparative Examples, but the present invention should not be construed as being limited thereto. All of the “parts” and “percent” are given by weight unless otherwise indicated.
Reference Example
Ordinary commercial polytetramethylene ether glycol (PTMG) were analyzed to determine their bulk viscosity and number-average molecular weight, and the molecular weight distribution of the polymer was calculated from the measured data. The results are shown in Table 1 below. The calculated value of molecular weight distribution of the polymer was almost near to 2.0, the molecular weight distribution value of polytetramethylene ether glycol theoretically estimated from cationic polymerization of tetrahydrofuran. This confirms that the molecular weight distribution of the polymer analyzed is broad.
TABLE 1
Hydroxyl
Number-
Molecular
Value
Average
Viscosity
Weight
PTMG
(mg
Molecular
at 40° C.
Distribution
Manufacturer
KOH/g)
Weight (Mn)
(poise)
(Mvis/Mn)
(a)
117.9
952
2.89
2.06
55.0
2040
14.46
2.05
(b)
109.5
1025
3.17
2.00
55.7
2014
12.42
1.99
Examples 1 to 3
100 parts of a sample, polytetramethylene ether glycol obtained in a known method with a fluorosulfonic acid catalyst [hydroxyl value=119.4 mgKOH/g; number-average molecular weight=940; bulk viscosity=2.82 poises (40° C.); molecular weight distribution (Mvis/Mn)=2.06], 100 parts of tetrahydrofuran and 100 parts of aqueous 30% sulfuric acid solution were put into a 500-cc four-neck flask (equipped with a thermometer and a stirrer) with each mouth being stopped with a separating cock, and stirred and mixed at 70° C. for 30 minutes, and then statically separated into two layers. The lower layer, aqueous sulfuric acid layer was removed through liquid-liquid separation. The upper organic layer was neutralized with calcium hydroxide and tetrahydrofuran was evaporated away. 100 parts of toluene was added thereto and subjected to azeotropic dehydration. This was filtered with a filtration aid, and toluene was evaporated away under reduced pressure from the filtrate to obtain the intended polytetramethylene ether glycol.
Next, the concentration of the aqueous sulfuric acid solution was changed to 40% (Example 2) and to 50% (Example 3), and the sample was processed in the same manner as above to obtain the fractionated polytetramethylene ether glycol. The yield, the hydroxyl value, the number-average molecular weight and the molecular weight distribution of each sample are shown in Table 2 below. The GPC (gel permeation chromatography) curve (columns, TSK G-2500H, XG-4000H; tetrahydrofuran solvent, 40° C.) of the polytetramethylene ether glycol obtained in each Example is shown in FIG. 1 .
Example 4
125 parts of a sample, polytetramethylene ether glycol obtained in a known method with an acetic anhydride-perchloric acid (HClO 4 ) catalyst [hydroxyl value=66.0 mg KOH/g; number-average molecular weight=1700; bulk viscosity=10.57 poises (40° C.); molecular weight distribution (Mvis/Mn)=2.13], 100 parts of tetrahydrofuran and 125 parts of aqueous 30% sulfuric acid solution were stirred and mixed at 70° C. for 30 minutes and subjected to extraction operation. This was then processed in the same manner as in Example 1. The results of the product obtained herein are given in Table 2 below.
TABLE 2
PTMG
Sulfuric Acid
Molecular
Concentration
Average
40° C. Bulk
Weight
Production of
for Fractional
Yield
OH Value
molecular
Viscosity
Distribution
Example
Sample PTMG
Extraction
(%)
(mg KOH/g)
weight
(poise)
(Mvis/Mn)
Sample
Fluorosulfonic
—
100
119.4
940
2.82
2.06
Example 1
Acid Process
30
95.7
108.2
1037
2.90
1.89
Example 2
40
82.5
97.0
1157
3.23
1.79
Example 3
50
69.9
84.4
1329
3.70
1.66
Sample
Acetic
—
100
66.0
1700
10.57
2.13
Example 4
Anhydride-
30
93.6
55.0
2040
10.58
1.82
Perchloric Acid
Process
Examples 5 to 7 and Comparative Example 1
400 parts of tetrahydrofuran was put into a one-liter four-neck flask (equipped with a thermometer and a stirrer), and 4.0 parts of antimony pentachloride (SbCl 5 ) was added thereto with cooling at 0° C. Then, 80 parts of 30% fuming sulfuric acid was added thereto over a period of 2 hours, and the monomer was thus polymerized at 0° C. for further 4 hours. The polymerization liquid was divided into four portions, and 122 parts [Comparative Example], 46 parts, 41 parts or 27 parts of water was separately added to each portion to thereby control the sulfuric acid concentration therein. With that, this was mixed and stirred at 60° C. for 60 minutes, and then statically left for fractional extraction.
Next, this was processed in the same manner as in Example 1, and the properties of the thus-obtained polytetramethylene ether glycol are shown in Table 3 below as Comparative Example 1 and Examples 5, 6 and 7.
Examples 8 and 9 and Comparative Example 2
The same apparatus as in Examples 5 to 7 was used. 50 parts of fluorosulfonic acid was added to 500 parts of tetrahydrofuran kept at 30° C., over a period of 1 hour, and then polymerized for further 10 hours. The polymerization liquid was divided into three portions, and 117 parts [Comparative Example], 40 parts or 27 parts of water was separately added to each portion to thereby decompose fluorosulfonic acid therein, and the concentration of the resulting sulfuric acid was thereby controlled. With that, each portion was subjected to fractional extraction at 80° C. for 90 minutes, and then this was processed in the same manner as in Example 1. The properties of the thus-obtained polytetramethylene glycol ether are shown in Table 3 below as Comparative Example 2 and Examples 8 and 9.
Example 10 and Comparative Example 3
300 parts of tetrahydrofuran and 100 parts of 3-methyltetrahydrofuran were put into the same apparatus as in Examples 5 to 7, and 4.0 parts of antimony pentachloride was added thereto with cooling at 0° C. Then, 50 parts of 30% fuming sulfuric acid was added thereto over a period of 2 hours, and the monomers were thus polymerized at 0° C. for further 4 hours. The polymerization liquid was divided into two portions, and 164 parts [Comparative Example] or 26.7 parts of water was separately added to each portion to thereby control the sulfuric acid concentration therein. With that, this was mixed and stirred at 60° C. for 60 minutes, and then statically left for fractional extraction. Next, this was processed in the same manner as in Example 1, and the properties of the thus-obtained copolyether glycol are shown in Table 3 below as Comparative Example 3 and Example 10.
TABLE 3
PTMG
Sulfuric Acid
Molecular
Concentration for
Average
40° C. Bulk
Weight
Fractional
Yield
OH Value
molecular
Viscosity
Distribution
Extraction
(%)
(mg KOH/g)
weight
(poise)
(Mvis/Mn)
1) tetrahydrofuran/fuming sulfuric acid/SbCl 5
Comparative Example 1
14
68
78.5
940
2.82
2.06
Example 5
30
64
71.5
1037
2.90
1.89
Example 6
40
62
70.4
1157
3.23
1.79
Example 7
50
58
68.0
1329
3.70
1.66
2) tetrahydrofuran/fluorosulfonic acid
Comparative Example 2
14
64
115.0
984
3.01
2.03
Example 8
30
58
109.1
1029
2.77
1.86
Example 9
40
51
94.8
1183
3.24
1.75
3) tetrahydrofuran 3-methyltetrahydrofuran/fuming sulfuric acid/SbCl 5
Comparative Example 3
14
60
36.1
3100
41.5
2.35
Example 10
50
54
26.9
4160
51.7
1.95
Example 11
The aqueous sulfuric acid layer separated by the same extraction operation as in Example 4 was neutralized with calcium hydroxide and tetrahydrofuran was evaporated away. 100 parts of toluene was added thereto and subjected to azeotropic dehydration. This was filtered with a filtration aid, and toluene was evaporated away under reduced pressure from the filtrate to obtain the intended polytetramethylene glycol [hydroxyl value=6.2 mg KOH/g; number-average molecular weight=505; yield=6.2%]. The yield is a value in comparison with the polytetramethylene ether glycol charged at the beginning in Example 4. As shown in this Example, the low-molecular weight fraction dissolved in the sulfuric acid-containing aqueous layer separated by the fractional operation can be obtained as a low-molecular weight polyether-polyol by adding further water and/or alkali substance to the sulfuric acid-containing aqueous layer and repeatedly carrying out the fractional extraction operation, followed by recovering and purifying it.
According to the method of the present invention for the molecular weight distribution control of polyether-polyol, it is possible to industrially advantageously control the molecular weight distribution of polyether-polyol containing tetrahydrofuran units which is produced through polymerization of tetrahydrofuran or copolymerization of tetrahydrofuran with any other cyclic ether.
While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
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A method for producing a polyether-polyol having a narrow molecular weight distribution, which comprises carrying out selective fractional extraction of the low-molecular weight component from a polyether-polyol (A) having an average molecular weight of from 500 to 4500 represented by formula (1):
HO—[(CH 2 ) 4 O] n —[(CR 1 R 2 ) p O] q —H (1)
wherein R 1 and R 2 , which may be the same or different, each represents a hydrogen atom or a linear or branched alkyl group having from 1 to 5 carbon atoms; n indicates a positive integer; p indicates an integer of from 1 to 8; and q indicates 0 or a positive integer, by the use of an aqueous solution (C) containing from 15 to 70 wt % sulfuric acid at a room temperature to 100° C., to thereby suitably determine the amount of the aqueous sulfuric acid solution to the overall organic layer and the sulfuric acid concentration in accordance with the molecular weight and molecular weight distribution of the intended polyether-polyol to be fractionally extracted.
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This application claims the benefit, under 35 U.S.C. § 365 of International Application PCT/EP02/00099, filed Jan. 8, 2002, which was published in accordance with PCT Article 21(2) on Jul. 18, 2002 in German and which claims the benefit of German patent application No. 10101500.3, filed Jan. 12, 2001 and German patent application No. 10115702.9 filed Mar. 29, 2001.
BACKGROUND OF THE INVENTION
The present invention relates to an optical compensation element for influencing wavefronts, as claimed in the precharacterizing clause of claim 1 .
A compensation element such as this is known from JP 10-221703.
SUMMARY OF THE INVENTION
One object of the invention is to propose a compensation element which is better than this.
For this purpose, the invention provides that each main electrode, or a majority of the main electrodes, be connected to a transverse electrode at one, and only at one, point. This has the advantage that up to 50% of the contact electrodes can be saved. In contrast to the main compensation element, there is no need in this case to match the electrical voltages on both sides of the main electrodes precisely to one another. This results in greater design freedom, since a connection need be provided on only one side of the main electrodes. Furthermore, the number of drive electrodes that are required is reduced.
If the transverse electrode and drive electrode are composed of the same material, with the cross section of the transverse electrode being smaller than that of the main electrode, then this has the advantage of a large voltage drop along the transverse electrode, so that a large potential change can be achieved in a short distance. The voltage drop on the transverse electrode is in this case greater than on the drive electrode, and the transverse electrode does not need to have a high resistivity. A further advantage is that a small voltage drop occurs on the main electrode, thus allowing faster potential changes to be achieved and a potential which is as uniform as possible to be achieved over the entire main electrode, even when using smaller resistances.
The main electrodes are advantageously arranged in an essentially rotationally symmetrical manner and have a constant voltage with the same mathematical sign for a constant radius. This has the advantage that, when a large number of switching materials are used, for example ferroelectric liquid crystals, the same switching response, that is to say the same optical change, is obtained over the ring which corresponds to a specific radius. If a nematic material is used as the switching material, the applied voltages may also have different mathematical signs since this has no influence on the optical effect that can be achieved with these materials. However, in the case of other switching materials, different mathematical signs would result in a different reaction. Depending on the desired phase correction profile, geometries other than rotationally symmetrical geometries may also advantageously be used.
The invention provides that the main electrodes are in the form of virtually closed rings with different radii, and are connected to the transverse electrode on their sides opposite the opening of the ring. This has the advantage that as large a proportion as possible of the available area is covered by the desired main electrode shape, and only a small portion of the surface is occupied by the transverse electrode, that is to say for supplying potential, if the transverse electrode is passed through the opening in the respective rings. A circular area is advantageously covered with as high a filling factor as possible and with the main electrodes arranged closely adjacent to one another, but not touching one another. The transverse electrode advantageously has a broader cross section in the area of the openings in the rings. This has the advantage that a greater voltage drop occurs on the transverse electrode in the area of the connection to the respective rings. This results in a wider usable potential range with a lower operating voltage. The potential which is tapped off from the transverse electrodes is held via the rings of the respective main electrode. This results in a potential profile which rises or falls in a rotationally symmetrical manner from the outside inward. The shape of the potential profile is governed by the choice of the tapping points on the transverse electrode.
According to one development of the invention, a correction electrode is arranged between the main electrodes. In this case, the correction electrode can be driven by means of a further drive electrode. The provision of one or more such correction electrodes has the advantage not only that it makes it possible to achieve a continuously rising or falling potential profile, but any desired potential profile.
The invention provides for both surfaces of the compensation element to have structured electrodes. This has the advantage that different optical effects are achieved or compensated for by different structuring of the electrodes. Not only rotationally symmetrical arrangements, but also surface distributions other than these are provided in this case. In this way, it is possible to compensate for tilt, focus, defocus and/or astigmatism, with potential profiles being provided in which a cylindrical lens, a wedge, a spherical lens and/or a nonspherical lens are combined in a single compensation element.
Different voltages are advantageously applied to the transverse electrode. The invention provides for the transverse electrode to have a variable cross section. This has the advantage that any desired nonlinear voltage drop is achieved, and hence a potential profile with a nonlinear rise. Any desired phase form of the compensation element can thus be achieved by modulation of the transverse electrode in this way.
Supply electrodes are advantageously arranged between the main electrode and the transverse electrode, with their contact points with the transverse electrode being arranged such that they are not equidistant. This represents an advantageous further variant for optimizing the potential profile.
According to the invention, different voltages are applied to the drive electrodes. This has the advantage that different voltages are applied to the main electrodes depending on the desired phase profile, with different phase profiles being achieved by varying the potential profiles in this way in conjunction with the phase shift/voltage characteristic of the material that is used. Different potential profiles can thus be achieved for the same voltage difference on the drive electrodes
It is likewise advantageous to apply different voltages to electrode structures which are arranged on opposite sides of a material with a variable refractive index. Even if, in the simplest case, a first of these electrode structures is flat, this allows the zero point of the potential which is applied to the other electrode structure of the transverse electrode to be shifted along the transverse electrode by varying the voltage which is applied to the first electrode structure. This allows different phase profiles to be achieved without any need to change the voltage which is applied to the other electrode structure.
An appliance according to the invention for reading and/or writing to optical recording media has a compensation element according to the invention. This has the advantage that it is possible to compensate for wavefront disturbances that occur, for example due to tilt or to a different layer thickness, particularly in the case of optical recording media with a high storage density. Wavefront disturbances such as these have a particularly critical influence on the accuracy of reading and writing to such optical recording media. These wavefront disturbances are optimally compensated for in an appliance according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages of the invention are also contained in the following description of exemplary embodiments. It is self-evident that the invention is not restricted to the described examples, but also includes modified forms with which those skilled in the art will be familiar.
In this case:
FIG. 1 shows a cross section through a compensation element;
FIG. 2 shows an electrode structure for spherical aberration;
FIG. 3 shows an electrode structure for coma aberration;
FIG. 4 shows a phase shift/voltage characteristic;
FIG. 5 shows an electrode structure with a correction electrode;
FIG. 6 shows a view of a detail from FIG. 5 ;
FIG. 7 shows the voltage drop across the transverse electrode according to a first variant relating to FIG. 5 ;
FIG. 8 shows the voltage drop across the transverse electrode according to a second variant relating to FIG. 5 ;
FIG. 9 shows an electrode structure with a modified transverse electrode;
FIG. 10 shows a view of a detail from FIG. 9 ;
FIG. 11 shows an electrode structure with a variable tap;
FIG. 12 shows a view of a detail from FIG. 11 ;
FIG. 13 shows the voltage drop for a transverse electrode with a constant cross section;
FIG. 14 shows the voltage drop for a transverse electrode with a variable cross section;
FIG. 15 shows the voltage drop for a transverse electrode with supply electrodes.
DETAILED DESCRIPTION
A compensation element according to the invention uses, by way of example, liquid crystals which modulate the phase of an incident light beam as a function of a local electrical field, as the material with a variable refractive index. In particular, liquid crystal elements with particularly efficient electrode structures are described in the following text. In this case, internal voltage drops are produced, which are available to the electrodes that modulate the wavefronts. This step allows a large number of electrodes to be operated with a low level of drive complexity. The large number of electrodes allows a high-resolution representation of the phase profile, and hence good correction of the wavefront. In particular, the elements are constructed such that they will also compensate for wavefront faults which vary with time. The method of operation will be described first of all with reference to two elements for correction of coma and spherical aberration.
The liquid crystal elements described here are used for correcting wavefront faults such as coma, spherical aberrations, etc. in optical systems. In this case, they are distinguished by an electrode structure which is as simple as possible, but which nevertheless is rich in tricks and restricts the drive that is required to a minimum. The drive is provided by only drive voltage, preferably an AC voltage at 1 kHz and at an amplitude, which can be regulated, of about 2–10 V. The internal voltage drops which are produced in the electrode structure make it possible to produce continuous wavefront deformations. In the exemplary embodiments, the electrode structure comprises only one transparent, conductive layer of indium tin oxide, also referred to as ITO, with a homogeneous surface resistance, and which can thus be produced very easily. Other transparent conductive materials such as polymers, etc., may, however, also advantageously be used for this purpose.
The elements which are described in the following text are used to compensate for coma or spherical aberrations, in particular in an appliance for reading or writing to optical recording media, for example a DVD pick-up head. Particularly in the case of future generations of such appliances, which will use shorter wavelength light sources, active compensation will be required. The trend for DVDs is to use objective lenses with a numerical aperture of NA=0.85, with a protective layer thickness of 0.1 mm. The spherical aberrations which occur when switching between different layers, for example from layer I to layer II, of a multilayer optical recording medium must be compensated for. If the substrates are relatively thick, the tolerances for disk tilting can be widened considerably by active tilt compensation.
The compensation element which is shown in the form of a cross section in FIG. 1 and is in the form of a liquid crystal compensation element 1 uses the local change in the refractive index in a thin liquid crystal layer 2 to modulate the wavefront.
The local refractive index distribution is produced by a suitable electrode structure 3 , and can be varied by the applied voltage. Meshing techniques, that is to say voltage drops which are produced on the electrode structure 3 , can be used to drastically reduce the number of electrodes that need to be driven. FIG. 1 shows a cross section through an element such as this. The electrode structures 3 , 3 ′ are composed of transparent conductive material, in this case indium tin oxide ITO, and are applied to glass substrates 4 , 4 ′ by means of photolithography. A layer of polyimide 5 is used for standard orientation of the liquid crystals 2 , and is rubbed in the preferred direction after being spun by spin coating. The cell is filled with liquid crystals 2 in a vacuum, and is finally sealed.
Spacers 6 prevent contact between the two electrode sides, and govern the cell thickness. The electrode structure 3 ′ is in this case shown as a ground electrode without any special structure.
An electrode structure for spherical aberrations is described in FIG. 2 . The electrode design that is shown in FIG. 2 allows compensation for wavefronts similar to a conical or spherical form. Only two drive electrodes 31 are required in this case. Two or more Pi phase modulations can thus be achieved depending on the cell thickness of the liquid crystal layer and on the material that is used.
A thin transverse electrode 32 is fed with the aid of two broad drive electrodes 31 . Since they are narrow, they have a far greater resistance for the same surface resistance. The voltage which is dropped on the drive electrodes 31 is thus virtually entirely dropped across the transverse electrode 32 . The respectively desired potential is picked up by means of the main electrodes 33 at different positions along the transverse electrode 32 . The main electrodes 33 are thus at the respectively associated potential. The number of phase stages and phase profiles, such as linear, logarithmic profiles, etc., can be achieved by the number and the position of the tapping points.
In this exemplary embodiment, the main electrodes 33 are in the form of circular rings, which are connected in the left-hand part to the transverse electrode 32 while, to the right of the center, they each have an opening 34 through which the transverse electrode 34 is passed to the right-hand drive electrode 31 .
An electrode structure for correcting coma aberrations is described in FIG. 3 . The illustrated electrode design makes it possible to compensate for wavefronts similar to coma. Only two drive electrodes 31 are likewise required in this case.
The difference from the spherical correction element shown in FIG. 2 is in the nature of the voltage tap. The transverse electrode 32 which is responsible for the voltage drop is now located outside the modulating area. Supply electrodes 35 tap off the desired potential from the transverse electrode 32 , and pass it to the main electrodes 36 .
The shape of the main electrodes 36 is in this case dependent on the desired phase modulation and on the potential distribution required for this purpose. The number of main electrodes 36 is dependent on the desired phase quantization. The potential on each individual main electrode 36 is optimized by means of a suitable potential tap at the tapping points 37 of the transverse electrode 32 over a specific operating range in the liquid crystal curve, see also FIG. 4 in this context, in order to allow correction that is as efficient as possible.
The choice of the operating voltage range and the choice of the tapping points 37 offer two degrees of freedom, which are required for continuous modulation.
The characteristic for the liquid crystal drive technique as illustrated in FIG. 4 , and which is also referred to as a liquid crystal calibration curve, shows the local phase shift in degrees [°] for a compensation element with the local potential predetermined by the electrode structure, plotted in volts [V]. This phase shift/voltage characteristic shows the phase shift that occurs when a potential difference is applied to the electrode structures 3 , 3 ′. A phase profile that is as suitable as possible is produced by suitable choice of the drive range in conjunction with the choice of the tapping points 37 on the transverse electrode 32 .
By way of example, a potential between 3.5 volts on the innermost ring and 5.2 volts on the outermost ring of the main electrodes 33 is recommended, in order to form profile whose curvature is as spherical as possible, for spherical correction. The profile can be optimized toward an ideal spherical shape by suitable choice of the tapping points 37 along the transverse electrode 32 . If a differently curved profile is desired, then the range between about 2 volts and 2.7 volts may be used, and a fairly linear range occurs, for example, between 2.7 volts and 3.3 volts, and, for example, above 6 volts.
The following should be noted with regard to the switching response and the switching times: the switching time of nematic liquid crystals depends essentially on the cell thickness and on the material that is used. The maximum achievable phase shift is in this case directly proportional to the cell thickness. Switching times of less than 10 ms can be achieved with nematic materials for correction of a wavefront with a peak to valley value of less than half lambda, that is to say less than half the wavelength of the light being used. For two or more lambda, it is only possible to achieve switching times of several hundred milliseconds.
Different liquid crystal mixtures exist, as well as other materials such as crystals, polymers, polymer liquid crystal combinations, which can be used as phase-shifting materials in elements such as these. Nematic liquid crystals are a highly suitable material for switching processes which are not too fast and are in the range from a few tens of milliseconds up to seconds, owing to their high birefringence with good transmission characteristics, low drive voltages, good polarization characteristics and low costs. Different materials must generally be used to reduce the switching times. However, these have other disadvantageous effects. In the case of crystals, these are, for example, the small change in the refractive index and the high drive voltages or, in the case of ferroelectric liquid crystals, the low birefringence with characteristics that change the polarization. If the idea according to the invention is used for faster materials such as these, then the disadvantages that have been mentioned become a secondary factor in comparison with the advantages which are achieved according to the invention.
The internal voltage drop which is made use of by the invention as described above also makes it possible to produce more complex electrodes and the phase profiles associated with them, for example a combined coma spherical element or 2D coma correction element. Liquid crystal compensation elements for the correction of aberrations have until now been produced only with direct supply lines to individual surface electrodes. In this case, the individual main electrodes are driven directly. Elements such as these have very large sudden phase changes, whose magnitude is governed by the number of control electrodes. In the case of a wavefront correction of 1* , the wavefront is corrected only in steps of /5, assuming five drive electrodes. The elements according to the invention require only a single drive voltage and, furthermore, allow much finer phase quantization. By way of example, this is /50 for fifty main electrodes.
The concept according to the invention of the voltage tap for compensation elements 1 as well as the concept of the supply electrodes 35 for main electrodes of any desired shape are particularly advantageous, as are the electrode design and the element for compensation for spherical aberrations and coma. Elements with different, opposite electrode structures are also provided according to the invention. In this case, according to the invention, electrode structures 3 , 3 ′ are arranged on the opposite glass substrates 4 , 4 ′. Coma and spherical aberrations are thus compensated for, for example, in one element. Elements according to the invention with relatively complex main electrodes allow any desired aberrations, switchable arrays such as checker gratings, wedge arrays, etc., asymmetric spherical correction, any desired radially symmetrical corrections or special functions that are locally integrated in the element. The scope of the invention likewise includes elements with internal electrodes that use the potential drop more than once. Not only solutions with two or more transverse electrodes 32 and one voltage supply but also solutions with two or more transverse electrodes 32 and two or more voltage suppliers are provided in this case. Multilayer electrode structures according to the invention can be produced, for example, with isolation layers and voltage conduits.
Further exemplary embodiments are described in the following text. These illustrate variants with particularly efficient electrode profiles for correcting the wavefront. All the extensions to the electrode structure which are illustrated in the following figures are used to produce rotationally symmetrical phase profiles which now have virtually any desired form. The examples mentioned above mainly describe spherical profiles, but also include the nonspherical profiles that are described in more detail here. The graphs provide a schematic illustration of the voltage profile dropped across the transverse electrode. The phase shift which results in the liquid crystal layer is achieved with the aid of the phase shift/voltage characteristics shown in FIG. 4 . Wavefronts corrected in different ways can thus be produced depending on the voltage range that is chosen.
FIG. 5 shows an electrode structure according to the invention with correction electrodes, drive electrodes 31 , a transverse electrode 32 and main electrodes 33 corresponding to those described in conjunction with FIG. 2 . The opening 34 is kept somewhat broader and allows correction electrodes 38 , 39 which are connected to at least one of the main electrodes 33 to be passed through.
This is illustrated in detail in FIG. 6 . This shows the transverse electrode 32 and the main electrodes 33 , which are illustrated only partially or at most incompletely, as well as the correction electrodes 38 , 39 . Like the transverse electrode 32 , these are passed through the opening 34 and are connected at contact points 30 to in each case one of the transverse electrodes 33 . Since this main electrode 33 is also connected to the transverse electrode 32 in the left-hand area of the electrode structure 3 , which is not shown here, this also changes the potential profile on the transverse electrode 32 . This extended spherical electrode profile makes it possible to achieve improved phase matching or production of higher-order rotationally symmetrical profiles. The correction electrodes 38 , 39 are used to vary the spherical profile.
FIG. 7 shows the voltage drop U, plotted along the vertical axis, against the radius R plotted on the horizontal axis. The mirror-image axis 7 for the voltage profile is shown by the radius R=0, that is to say at the center of the annular main electrodes 22 . K 1 , K 2 denote the points at which the correction electrodes act. As can be seen, the potential profile between the maximum radius Rmax and the points K 1 , K 2 at which the correction electrodes act is virtually linear, while there is a kink at the points K 1 , K 2 .
FIG. 8 shows a different profile of the voltage drop corresponding to FIG. 5 , with the voltages on the correction electrodes 38 , 39 being chosen such that the gradient between the points K 1 and K 2 is opposite to that in the rest of the profile.
FIG. 9 shows an electrode structure with a modified transverse electrode 32 . As described in conjunction with FIG. 1 , the transverse electrode 32 in the left-hand area is connected to the main electrodes 33 , while an opening 34 is provided in the right-hand area. The transverse electrode 32 is provided with thickened regions 8 in the left-hand area. Its resistance is thus changed locally, that is to say the voltages that are tapped off vary with respect to one another despite the distance between the tapping points being the same. Once again, this allows the wavefront to be ideally matched to the desired characteristics.
FIG. 10 shows the modified transverse electrode 32 illustrated schematically and enlarged. The thickened regions 8 in this case not only exist in constant broadened regions of the cross section, which are uniform and extend over a certain range, but are also produced in irregular broadened regions, as illustrated further to the right.
FIG. 11 shows the electrode structure from FIG. 2 with a variable tap on the transverse electrode 32 . The tapping points 37 at which the main electrodes 33 are connected to the transverse electrode 32 are no longer arranged at equal intervals, in contrast to FIG. 2 , but are separated by different distances from one another. Supply electrodes 35 are provided for the connection between the transverse electrode 32 and the main electrodes 33 .
A detail of this is shown in FIG. 12 .
FIG. 13 shows the voltage drop for a transverse electrode with a constant cross section. The graph in this case corresponds to those in FIGS. 7 and 8 . This shows the linear profile over the radius with the gradient angle α. In this case, α cannot exceed the maximum value of αmax=45°.
FIG. 14 shows a voltage drop corresponding to that in FIG. 13 , but for a transverse electrode with a variable cross section. The voltage rise α varies in a corresponding way to the variation in the cross section although, in this case as well, it cannot exceed an upper value αmax.
FIG. 15 shows a voltage drop corresponding to that in the previous figures, but using supply electrodes 35 . The spreading and compression of the distances between the tapping points 37 which are possible in this case make it possible to achieve a gradient α which is greater than the αmax in the previous diagrams. This is also due, inter alia, to the small cross section of the supply electrodes 35 , which allow closer staggering.
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The invention relates to an optical compensation element comprising a first transparent surface on which a transparent electrode is arranged; a second transparent surface on which a plurality of transparent main electrodes are arranged, several of which being respectively connected to control electrodes via a transverse electrode; and a material having a refractive index which changes according to the voltage applied, said material being arranged between the first and second transparent surfaces. The aim of the invention is to improve said compensation element. To this end, each main electrode is connected to a transverse electrode at a precise location.
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BACKGROUND AND HISTORY OF THE INVENTION
The present invention relates to an adjustable wall penetration framing member of the type that can be positioned in an existing door opening or any external or internal wall penetration of conventional construction and of the type that can be adjusted to accommodate irregularities in the rough opening.
It is frequently desired to improve old building units and to replace the doors provided in the old buildings with up-to-date and modern replacement doors. There is usually some difficulty associated with this replacement since the door frequently must be cut to special sizes and shapes. This is particularly true of the threshold of either an old or a new doorway which must be positioned on warped or distorted floor boards. Accordingly, it is an object of this invention to provide a complete adjustable door frame member, especially an adjustable threshold, which may be inserted into an old or a new doorway or other external or internal wall penetration which, for one reason or another, may be out of square, warped or irregular. The adjustable member must not only have the ability to accommodate the irregularities of the opening but also, in the case of an outside door, must be impervious to the elements such as wind and rain.
SUMMARY OF THE INVENTION
An adjustable wall penetration framing member is provided which is not only easily adjustable to accommodate wall penetration irregularities but which also prevents the infiltration of wind or rain through the adjustable member. The member consists of a first trough or channel which is fastened on the inside of the wall penetration with its open side facing the penetration cavity. Over this open trough is slid a second open trough with its open side facing away from the cavity. Between the first and second open troughs is positioned a weatherseal material which preferably is a resilent deformable water impervious skinned foam. A plurality of spaced screws in threaded engagement with the first open trough holds the second open trough in a position relative to the first open trough. A bracket and nut fixed on the screw engage the underside of the second open trough to assist in the positioning thereof. Each of the plurality of screws is accessible through the second trough thereby permitting easy adjustment of the relative positions of the two troughs. The apparatus of the invention is particularly suitable for an adjustable door threshold although it may be adapted for use as any portion of the complete door frame or for use as any portion of any part of the frame for framing a wall penetration.
BRIEF DESCRIPTION OF THE DRAWING
The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawing in which FIG. 1 illustrates a cross-sectional view of the adjustable complete door frame member.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the invention has been illustrated in the embodiment of an adjustable threshold 10. The threshold consists of an aluminum sill band 16 which engages an aluminum basic sill 14 which rests on a wooden substrate 12. The aluminum basic sill 14 in part consists of an upwardly facing open trough or channel 30 which has relatively spaced sidewalls 26. Fitting over the channel 30 in sliding relationship is a high rise threshold 20. High rise threshold 20 may consist of any suitable material such a polyvinyl chloride or extruded aluminum. The high rise threshold 20 includes relatively spaced sidewalls 24 on each side thereof and also relatively spaced ribs 28 which extend along at least a portion of the length of the elongated trough 20. In its assembled configuration the high rise threshold 20 has an outer side which lies adjacent to the bottom of the closed door 42 and an inner side which faces the base 30. The high rise threshold 20 with the relatively spaced sidewalls 24 is adapted to slidingly fit over the channel 30 and the relatively spaced sidewalls 26 of the channel 30. The ribs 28 on the inside of the high rise threshold 20 define three compartments on the interior of the trough 20. The middle compartment contains adjusting means which permit the relative adjustment of the high rise threshold 20 with respect to the base member 30. The outermost two compartments defined by the ribs 28 are filled with a weatherseal means 22 which contacts both the high rise threshold 20 and at least a portion of the open channel base member 30. By this weatherseal means 22, water and air penetration from the outside of the doorframe to the interior of the structure is prevented or at least substantially reduced. In a preferred embodiment the weatherseal means is a resilient, deformable water impervious material such as skinned foam. Also in a preferred embodiment of the invention as illustrated in FIG. 1, the threshold is built with a slight outward and downward pitch so that rain water drains away from the door unit. Accordingly, the high rise section of the threshold is at the highest position of the threshold and water does not have a tendency to accumulate therein. To further assure that water is not trapped in a pool in the channel section 30, weep holes 18 are drilled in the exterior sidewall 26 of base 30 to facilitate the drainage of the adjustable threshold section.
Continuing the description of the adjustable high rise section of the threshold 10, the adjustable portion 20 of the high rise threshold is fastened to the base member 30 by means of screw 32. Screw 32 penetrates through the trough 20 and is accessible therethrough for adjustment. Screw 32 engages the exterior surface of the trough 20 to hold the trough 20 down. Screw 32 also engages channel 30 in threaded engagement by means of threaded opening 34 so that by turning the screw 32 in a clockwise direction the threshold is lowered and by turning the screw 32 in a counterclockwise direction the threshold is raised. In order to accommodate the adjustable motion of the screw 32 a hole 36 is drilled in the substrate 12. In addition to the head of the screw 32 which holds down the adjustable threshold member 20 the adjustable means includes bracket 38 carried by screw 32 and held in position by a lock-nut 40. The bracket 38 engages an inner portion of the adjustable member 20 (the ribs 28 as shown in the illustration) and is held in its axial position by the lock-nut 40. The lock-nut 40 locks to the threaded screw in a fixed position so that by turning the screw 32 the nut 40 is also caused to turn relative to the bracket 38. By this means adjustable threshold member 20 is held between the head of the screw 32 and the bracket 38 so that when the screw is raised or lowered the adjustable threshold member 20 is also raised or lowered. It should be recognized that in the above discussion of the adjustable threshold of the instant invention the member is elongated and has a plurality of adjusting means located at spaced positions along the length of the elongated members.
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An adjustable wall penetration framing member which is adjustable at any point by raising or lowering an adjustment screw and which prevents the infiltration of water and air into the interior of a building through the adjustable member.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 10/053,022, filed Nov. 2, 2001, U.S. Pat. No. 6,527,343 issued Mar. 4, 2003, which is a continuation of application Ser. No. 09/447,173, filed Nov. 22, 1999, U.S. Pat. No. 6,312,054, issued Nov. 6, 2001, which is a continuation-in-part of application Ser. No. 09/178,818 filed Oct. 26, 1998, U.S. Pat. No. 6,086,150 issued Jul. 11, 2000.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
BACKGROUND OF THE INVENTION
This invention relates generally to swimming pool accessories, and in particular to a buoyant lounge chair for supporting a person in a seated position while the chair is floating in water.
Swimming pools offer personal recreation and relaxation in a variety of settings, for example in private homes, apartment complexes, motels, resorts and country clubs. Various flotation devices including buoyant chairs, rafts, water wings, floating cushions, body floats and air mattresses are used by swimmers as an aid for floating and relaxing on the surface of the water, while remaining seated upright, reclining or lounging, either partially or completely submerged. These items of pool furniture include flotation cushions made of a buoyant material such as open cell foam, closed cell foam, cork, kapok, fiberglass or balsa wood, which are sealed within a protective outer covering.
A popular item of pool furniture is the buoyant lounge chair that permits a swimmer to relax on the surface of the water in a seated, semi-reclining orientation. In some lounge chair designs, the angle of recline is fixed and determined by the form of the rigid frame on which buoyancy cushions are attached, for example as shown in U.S. Pat. No. 6,086,150, which is incorporated herein by reference. In other lounge chair designs, the chair back is pivotably coupled to the frame on which buoyancy cushions are attached, for example as shown in U.S. Pat. No. 6,312,054, which is incorporated herein by reference. Those buoyant lounge chairs, manufactured and sold by Texas Recreation Corporation of Wichita Falls, Tex. have met with considerable commercial success. The present invention was stimulated by the need for a buoyant lounge chair having pivotal chair back that can be set in an upright, semi-reclining sitting position, in which the pool chair functions essentially as a buoyant chair, to a fully folded, minimum profile configuration for storage purposes, and to facilitate handling and shipment. For convenience and comfort, the back rest should be easily set in the standard angle of recline provided by conventional fixed-back lounge chairs.
According to another conventional buoyant lounge chair arrangement, as shown in U.S. Pat. No. 4,662,852, the back rest frame is pivotally connected to the seat frame and is inclined against a rear cross bar, and the seat frame is braced by releasable engagement of a slotted bracket with a forward cross bar. The angle of recline is adjusted by extending and retracting the slotted bracket relative to the forward cross bar. This movement translates into angle of recline adjustment as the two sections pivot about a common hinge axis.
An important consideration in the design and construction of buoyant lounge chairs, including those including a foldable back, is the maintenance of a water-tight seal about the cushion material and around the welded metal frame. The interlocking components of the foldable seat back coupling apparatus should also be protected.
The external surface of the lounge chair is susceptible to attack by mildew, fungus, surface hardening, cracking and shrinking that are caused by long-term exposure to water, pool chemicals and solar radiation. Consequently, lounge chairs as well as other buoyant flotation devices are desirably protected by a durable, non-reactive coating of plastic material, such as vinyl. The protective coating must be soft, pliable and able to withstand rough handling and high shear forces along the joinder lines between the chair arms, the chair seat, and along the flex lines between the chair back and chair seat. The protective coating is applied by various processes, including dipping and spraying, preferably as set forth in our U.S. Pat. No. 6,086,150, incorporated herein by reference.
Another limitation imposed by the construction of conventional lounge chairs is that the buoyant arm support sections are subject to tearing or deformation, and are also subject to collapse and separation from the chair frame at the interface between the arm support sections and the chair seat.
Special care should be taken in the construction of buoyant lounge chairs to provide sufficient buoyancy material to maintain a stable upright orientation while the occupant is in a semi-reclining or sitting orientation. The buoyant lounge chair can overturn in response to shifting of its center of buoyancy as the occupant turns or moves about.
SUMMARY OF THE INVENTION
The buoyant lounge chair of the present invention provides stable support for a swimmer in an upright, semi-reclining or sitting position while the chair is floating in a swimming pool. Interconnected rigid frame members collectively form an open chair frame. In the preferred embodiment, the frame members include a seat frame, left and right side arm frames attached to the seat frame, and a movable back frame. The back frame is pivotally coupled to the seat frame on opposite sides by dual axle shafts. A manually operable clutch is mounted on each axle shaft for releasably connecting the seat frame to the back frame. Each clutch is manually releasable to permit pivotal movement of the back frame relative to the seat frame, and is manually engagable to fix the angle of recline of the back frame relative to the seat frame, for example for use in the upright sitting position.
Buoyant cushions are attached to the frame members, thereby forming a chair seat, a chair back, left and right chair arms and a bolster block. The buoyant cushions forming the chair seat, the chair arms, the chair back and the bolster block each include layers of buoyant cushion material secured and sealed together by an adhesive deposit in overlapping relation, with each chair frame member being enclosed and sealed between a pair of buoyant layers. Each axle shaft and clutch are also enclosed between a pair of the buoyant layers. Each clutch includes a manual actuator that extends laterally through a passage formed in a pair of buoyant arm cushions, and projects externally of each chair arm at a side location in which it can be conveniently manipulated for engaging and releasing the clutch while the operator is seated or reclining on the lounge chair.
Each buoyant arm support section is reinforced by an upright arm support riser that is laterally offset from the seat frame and by a horizontal arm rest segment that is vertically offset from the seat frame. The left and right buoyant chair arms are stabilized and reinforced against collapse and separation from the chair frame by the upright arm support risers and the horizontal arm rest segments that are sandwiched between the buoyant arm support cushions.
In the preferred embodiment, the left and right arm support cushions project aft of the pivotal union between the chair seat the chair back. According to this arrangement, the aft projecting portions of the arm support cushions overlap the laterally opposite end portions of the bolster block. The arm support cushions are reinforced against deflection and separation from the chair frame by an aft extension bar attached to the arm rest frame. The extension bar is laterally offset from the seat frame and from the back frame, and projects aft of the pivotal clutch union. The buoyant arm support cushions are further reinforced and stabilized against vertical deflection by the clutch actuator which extends laterally through the buoyant arm cushions.
According to another aspect of the invention, the upright floating stability of the lounge chair is improved by extension portions of the buoyant arm cushions that project aft of the chair seat, substantially overlapping the opposite end portions of the bolster block. The upright floating stability of the lounge chair is also improved by a seat frame assembly including left and right seat frame segments each including an angled connecting portion attached to a central seat frame segment. The angled connecting portions slope downwardly relative to the seat frame segments, whereby the buoyant cushions in combination with the seat frame segments form a leg support section that slopes downwardly relative to the chair seat and buoyant arm cushions.
The floating stability of the lounge chair is further improved by buoyant arm rest cushions which are mounted on top of the left arm and right arm support cushions. The arm rest cushions extend aft of the seat frame/back frame pivotal clutch union, substantially in flush alignment with the bolster block when the seat back is set in the upright lounging position.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying drawing is incorporated into and forms a part of the specification to illustrate the preferred embodiments of the present invention. Various advantages and features of the invention will be understood from the following detailed description taken in connection with the appended claims and with reference to the attached drawing figures in which:
FIG. 1 is perspective view of a buoyant lounge chair constructed according to the preferred embodiment of the present invention;
FIG. 2 is a perspective view thereof showing interconnected rigid frame members including a pivotally coupled back frame collectively forming an open chair frame;
FIG. 3 is a perspective view showing first and second layers of buoyant cushion material secured together in overlapping relation, with the seat frame and back frame of the chair being sandwiched between the buoyant layers, the top layer forming a continuous body support surface that transitions through the pivotal union between the seat frame and the back frame;
FIG. 4 is a perspective view of a portion of the seat frame, showing a threaded coupling nut welded onto a central seat frame segment;
FIG. 5 is a perspective view similar to FIG. 3, showing the assembly of buoyant arm support cushions onto the left and right arm frames;
FIG. 6 is a rear perspective view of the buoyant lounge chair showing a bolster frame sandwiched between a pair of buoyant cushions;
FIG. 7 is a rear elevational view of the buoyant lounge chair shown in FIG. 1;
FIG. 8 is a perspective view of the open chair frame of FIG. 2 with the pivotal back frame in the extended, fully reclining (body float) position;
FIG. 9 is a perspective view of the open chair frame of FIG. 2, showing the back frame in the folded, minimum profile (storage/shipping) position;
FIG. 10 is a perspective view of the fully assembled buoyant lounge chair of FIG. 1 with the back unfolded to the fully reclining (body float) position;
FIG. 11 is a perspective view of the buoyant lounge chair of FIG. 1 with the back folded forward in the minimum profile (storage/shipping) position;
FIG. 12 is a perspective view of the buoyant lounge chair shown in FIG. 1, partially broken away, showing details of the pivotal coupling and clutch assembly which connect the foldable back frame to the seat frame;
FIG. 13 is a sectional view, partially broken away, taken along the line 13 — 13 of FIG. 1 showing abutting cushion layers that are adhesively sealed together around a portion of the back frame;
FIG. 14 is a perspective view, partially broken away, of the pivotal coupling and clutch assembly shown in FIG. 12;
FIG. 15 is a perspective view, partially broken away, of an alternative embodiment of the pivotal coupling and clutch assembly;
FIG. 16 is an exploded, perspective view of the pivotal coupling and clutch assembly of the present invention;
FIG. 17 is an exploded, perspective view similar to FIG. 16, illustrating an alternative embodiment of the pivotal coupling and clutch assembly;
FIG. 18 is a perspective view, partially broken away, of the inside coupling clutch member shown in FIG. 17;
FIG. 19 is a sectional view of the pivotal coupling and clutch assembly shown in FIG. 17, with the clutch assembly in the engaged operative position;
FIG. 20 is a perspective view of the tubular steel coupling sleeve shown in FIG. 19;
FIG. 21 is a left side elevational view thereof;
FIG. 22 is a right side elevational view thereof; and,
FIG. 23 is a perspective view of an alternative embodiment of the buoyant lounge chair of FIG. 1 which includes an extended leg support section.
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the invention will now be described with reference to various examples of how the invention can best be made and used. Like reference numerals are used throughout the description and several views of the drawing to indicate like or corresponding parts.
Referring now to FIG. 1 -FIG. 7, there is illustrated an exemplary embodiment of a light-weight buoyant lounge chair 10 for selectively supporting a person in seated, semi-reclining and fully reclining lounge positions while the chair is floating in water. The lounge chair 10 includes an adjustable chair back 12 , chair arms 14 , 16 , a chair seat 18 and arm rest cushions 20 , 22 which provide full body support in the seated, upright, semi-reclining, reclining and fully reclining lounge positions.
The operative upright floating position refers to the flotation orientation of the lounge chair 10 with the chair back 12 and chair arms 14 , 16 generally upright while the chair seat 18 is generally horizontal and at least partially submerged as indicated in FIG. 1 . When the lounge chair is floating in water, the occupant is supported in a comfortable lounging orientation, with his arms being supported by the left arm rest cushion 20 , the right arm rest cushion 22 and his head is supported by a head support cushion 24 . The occupant's legs are supported by a leg support section 26 which projects forwardly from the chair seat 18 .
Buoyancy sufficient to support an adult occupant having a body weight up to 250 lbs. is provided by multiple pairs of overlapping buoyant cushions that are attached to an open chair frame 28 shown in FIG. 2 . The open chair frame 28 is a skeleton frame formed by interconnected rigid frame members, preferably {fraction (5/16)} inch diameter steel rod segments that are welded together. The rigid steel rod segments form a seat frame 30 , a back frame 32 that is pivotally coupled to the seat frame along a pivotal axis A and is adjustable through an incline angle α, which ranges from about 10° in the folded configuration (FIG. 11) to about 180° in the fully extended, body float configuration (FIG. 10 ). A left arm frame 34 and a right arm frame 36 are attached to the seat frame but are separated from the back frame to permit free movement of the back frame during adjustment of the recline angle α. A bolster frame 38 is welded onto the back frame 32 , projecting aft of the chair frame and extending laterally substantially from the left side to the right side of the chair frame 28 .
Buoyant cushions formed by overlapping layers of buoyant cushion material are attached to the individual steel rod frame segments, thereby forming the buoyant chair back 12 , the left chair arm 14 , the right chair arm 16 , the chair seat 18 and a bolster block 40 . Each buoyant cushion is formed by a pair of overlapping layers of buoyant material, preferably slabs of closed cell polyurethane foam F having a density in the range of 1-6 lbs./cu.ft. Each closed cell foam layer is in the form of a rectangular slab, having a typical thickness in the range of 1-2 inches, and is cut to form a lounge chair having an assembled height of 27 inches, a length of 30 inches and a width of 30 inches.
Referring again to FIG. 2, FIG. 3, FIG. 5, FIG. 6 and FIG. 13, overlapping pairs of buoyant cushions are attached and secured onto the chair frame members by an adhesive bonding agent, for example a deposit 42 of a fast setting contact cement, with the frame members being enclosed and sealed between the layers, thereby providing structural reinforcement for the soft, buoyant cushions. For this purpose, the chair seat 18 is formed by a pair of overlapping cushion layers 18 A, 18 B; the left chair arm is formed by a pair of overlapping arm support cushions 14 A, 14 B, with the left arm frame 34 being enclosed and sealed between the overlapping layers 14 A, 14 B.
Likewise, the right arm 16 is formed by a pair of overlapping cushion layers 16 A, 16 B that are adhesively bonded together with the right arm frame 36 being enclosed and sealed between the overlapping layers. The chair back 12 is also formed by overlapping cushion layers 12 A, 12 B which are adhesively bonded together, with the back frame 32 being enclosed and sealed between the overlapping cushion layers. The bolster block 40 is also formed by overlapping buoyant cushion layers 40 A, 40 B that are adhesively bonded together with the bolster frame 38 being enclosed and sealed between the overlapping cushion layers.
Referring again to FIG. 1 and FIG. 5, the left and right chair arms 14 , 16 are stabilized further by adhesive attachment to the left and right side edge portions of the chair seat 18 . The chair arms overlap the laterally opposite sides of the chair back 12 , but are not attached to it. The left and right arm support cushions are further stabilized by adhesive attachment to the left arm rest cushion 20 and right arm rest cushion 22 which bridge across the overlapping cushion layers 14 A, 14 B and 16 A, 16 B, respectively. As shown in FIG. 5 and FIG. 7, aft projecting end portions 14 C, 14 D and 16 C, 16 D of the left arm support 14 and right arm support 16 overlap the opposite ends of the bolster block 40 , which further improves the buoyancy and floating stability of the lounge chair.
The buoyant arm support sections 14 , 16 are reinforced by the side arm frames 34 , 36 . The side arm frame 34 includes an upright arm support riser segment 34 B that is laterally offset from the seat frame by an angled linking segment 34 C. The side arm frame also includes a horizontal arm rest segment 34 A that is vertically offset from the seat frame.
The right side arm frame is identically reinforced by a horizontal arm rest segment 36 A, an upright arm support riser 36 B and an angled linking segment 36 C attached to the seat frame 30 B. The left and right arm support cushions are thus stabilized and supported against collapse and separation from the chair frame by the rigid support provided by the left and right arm segments that are enclosed and sealed between the buoyant arm support cushions, as indicated in FIG. 13 .
The aft projecting arm support cushions 14 C, 14 D and 16 C, 16 D are reinforced against deflection and separation from the chair frame by extension bars 34 E, 36 E, respectively. The extension bars 34 E, 36 E are welded onto the side arm frames 34 , 36 , respectively. The extension bars are laterally offset from the seat frame 30 , and project aft of the pivotal union between the back frame 32 and the seat frame 30 . The upright floating stability of the lounge chair is improved by the aft extending portions of the buoyant arm cushions which project aft of the pivotal union, whereby the aft projecting portions substantially overlap the laterally opposite end portions of the bolster block 40 .
The upright floating stability of the lounge chair 10 is further improved by the seat frame assembly 30 which includes left and right seat frame segments 30 A, 30 B and a central seat frame segment 30 C. The central seat frame segment 30 C is connected on opposite ends to the seat frame side segments by angled connecting segments 30 D, 30 E. The seat frame segments are enclosed and sealed between the buoyant chair seat cushions 18 A, 18 B. The floating stability of the lounge chair is improved by the leg support section 26 that slopes downwardly from the chair seat 18 , as shown in FIG. 1 . The downward slope is provided by the angled seat frame segments 30 D, 30 E, as shown in FIG. 2 .
The floating stability of the lounge chair is also improved by attaching the bolster block 40 onto the back frame 32 so that its moment arm spacing relative to the pivotal axis A remains constant as the chair back is adjusted throughout its angle of incline range. Referring to FIG. 2, FIG. 5 and FIG. 6, the bolster frame 38 includes left and right bolster frame segments 38 A, 38 B that project downwardly from the back frame 32 , and are sandwiched between the lower and upper buoyant bolster cushions 40 A, 40 B. The bolster frame segments 38 A, 38 B maintain the bolster block 40 in a transverse orientation relative to the chair back 32 as the incline angle α is adjusted from one position to another. Preferably, the bolster frame segments 38 A, 38 B slope transversely so that the bolster block 40 is inclined by about 20° relative to the horizontal arm support segments 34 A, 36 A when the lounge chair back is in the upright floating position.
Referring now to FIG. 1 and FIG. 13, the overlapping buoyant cushions are bonded and sealed together by a thin layer of adhesive 42 . Additionally, the surface portions of the buoyant cushions bordering the lines of abutting engagement between the chair seat and the left and right chair arms, and between the chair back and the bolster block are further bonded together and sealed by a layer of flexible caulking material 44 . Preferably, the caulking material is a high grade, 15-25 year acrylic material that provides good adhesion to the surface of the closed cell foam, and can withstand high shear forces arising along the interface surfaces. After the caulking material 44 has been applied and cured, a layer of solvent-based vinyl coating material 46 is applied to the exposed external surfaces of the lounge chair. Preferably, the protective vinyl coating 46 is applied over the external surfaces of the lounge chair 10 while it is suspended on a threaded weldment 48 from a hanger strap as described and claimed in our co-pending application Ser. No. 09/178,818 filed Oct. 26, 1998.
Referring again to FIG. 1, FIG. 3 and FIG. 12, the buoyant cushions forming the chair seat 18 and the chair back 12 are preferably formed by first and second layers of buoyant cushion material 18 A, 18 B that are bonded together in overlapping relation by an adhesive deposit 42 . According to this arrangement, the layers of buoyant cushion material forming the chair seat 18 and the chair back 12 are integrally formed together, with the seat frame 30 and the back frame 32 being captured and sandwiched between the overlapping layers. The top buoyant layer 18 A forms a continuous body support surface that transitions smoothly through the incline angle α. The incline angle α can be varied through a range of from approximately 10° when the seat back is folded forward in the minimum profile position as shown in FIG. 11, to approximately 90° when the seat back 12 is in the upright position as shown in FIG. 1, and through approximately 180° when the seat back 12 is in the fully extended (body float) position as shown in FIG. 10 .
Referring again to FIG. 6, FIG. 7 and FIG. 11, a flexible tie-off grommet 50 is attached to the bolster frame 38 . The tie-off grommet 50 is enclosed and sealed between the lower and upper buoyant bolster layers 40 A, 40 B. An externally projecting portion of the tie-off grommet includes an eyelet for attachment to a tether line whereby the lounge chair 10 can be secured to a fixed structure such as a pool ladder so that the lounge chair will not be blown away during high winds. Also, the tie-off grommet can be used to hang the lounge chair from an overhead hook for inside sheltered storage, preferably with the lounge chair folded into its minimum profile configuration as shown in FIG. 11 .
According to an important feature of the present invention, the back frame 32 is pivotally coupled to the seat frame 30 by a pair of clutch assemblies 60 , 80 as shown in FIG. 2, FIG. 8 and FIG. 16 . The construction of the clutch assembly 80 is identical to the clutch assembly 80 . Referring in particular to FIG. 14 and FIG. 16, the clutch assembly 60 includes a fixed clutch member 62 attached to the seat frame 30 A and a rotatable clutch member 64 attached to the back frame 32 A. The fixed clutch member 62 and the rotatable clutch member 64 include complementary male and female end portions 62 A, 62 B and 64 A, 64 B that are adapted for mating engagement with each other when the clutch members are in the engaged position as shown in FIG. 14 . Preferably, the male and female end portions consist of V-shaped ribs 62 A, 64 A and V-shaped pockets 62 B, 64 B that alternate with each other, wherein the V-shaped ribs on each clutch member are dimensioned and conformed for nesting engagement within the V-shaped pockets on the other clutch member.
Each clutch member is intersected by a coupling aperture 62 C, 64 C, respectively, which are in concentric alignment with each other when the clutch members are engaged as shown in FIG. 14 . The fixed clutch member 62 and the rotatable clutch member 64 are mounted on a threaded axle shaft 66 which extends through the coupling apertures 62 C, 64 C. The rotatable clutch member is mounted for rotation on and axial movement along the axle shaft 66 from an engaged position, as shown in FIG. 14, in which the fixed clutch member and the movable clutch member are in contact with each other, to a disengaged position, as shown in FIG. 17, in which the fixed clutch member 62 and the rotatable clutch member 64 are separated from each other.
The angular position of the rotatable clutch member 64 relative to the fixed clutch member 62 is maintained by a manually operable actuator 68 and a compression tube 70 . Referring to FIG. 14, FIG. 17 and FIG. 18, the axle shaft 66 extends through the coupling apertures 62 C, 64 C of the fixed clutch member and rotatable clutch member, and also through the compression tube 70 . The threaded end 66 T of the axle shaft is engaged by a complementary threaded retainer 68 R coaxially embedded, preferably by molding, within the actuator knob 68 . As the actuator knob 68 is turned clockwise or counterclockwise, the actuator knob travels axially along the threaded end portion 66 T against or away from the compression tube 70 . The fixed clutch member 62 and the rotatable clutch member 64 are forced together in compressive engagement as the actuator knob 68 is rotated clockwise against the compression tube, and the clutch members 62 , 64 are permitted to pull apart as the actuator knob 68 is rotated counterclockwise and travels away from the compression tube. Rotation of the axle shaft 66 is prevented by engagement of a hex head portion 66 H within a complementary hex pocket 64 H formed in the rotatable clutch member 64 , as shown in FIG. 18 . Preferably, the axle shaft 66 includes a smooth, cylindrical bearing surface 66 S which is in registration with the coupling aperture 64 C. This permits the rotatable clutch member 64 to ride on a smooth bearing surface during rotation of the back frame.
The length of the compression tube 70 and the length of the threaded portion 66 T of the axle shaft 66 are selected appropriately so that the compression tube 70 extends through the side arm cushions 14 A, 14 B, with the threaded end portion 66 T and the actuator knob 68 projecting externally of the side arm frame cushion 14 B, as shown in FIG. 1 and FIG. 5 . The actuator knob 68 is conveniently located so that the operator can manually release and set each clutch to permit pivotal movement of the back frame 32 relative to the seat frame 30 , and to adjust and fix the angle of recline according to personal preference.
Referring to FIG. 1, FIG. 5 and FIG. 12, it will be appreciated that each clutch assembly 60 , 80 is covered by the overlapping buoyant cushions that form the chair seat and the chair back. Preferably, the clutch members are constructed of a high strength, moldable plastic material such as polyvinyl chloride (PVC) or nylon which does not corrode when exposed to water. The frame rod segments, which are made of steel, should be sealed and protected from exposure to water to prevent rust. For this purpose, the seat frame segments 30 A, 30 B and the back frame segments 32 A, 32 B are adhesively sealed between the overlapping buoyant cushions 12 A, 12 B as shown in FIG. 13 .
The water-tight seal is intensified and reinforced around the steel rod frame segments at the union with the clutch members by a first surface augmentation collar 72 and a second surface augmentation collar 74 . The augmentation collars 72 , 74 are formed as integrally molded parts of the clutch members 62 , 64 , and present enlarged side surfaces 72 S, 74 S, respectively, for adhesively bonding and forming a water-tight seal with the overlapping buoyant seat cushions 18 A, 18 B and overlapping buoyant back cushions 12 A, 12 B, as shown in FIG. 12 and FIG. 13 .
Referring now to FIG. 13, FIG. 15, FIG. 16, FIG. 17 and FIG. 19, the union between each clutch member and the frame segment is reinforced by a tubular steel coupling sleeve 76 which is molded into and embedded within the fixed clutch member 62 , and a tubular steel coupling sleeve 78 which is molded into and embedded within the body of the rotatable clutch member 64 . According to this arrangement, the tubular coupling sleeves 76 , 78 are preassembled and molded within the clutch members, and the surface augmentation collars 72 , 74 are integrally molded around the tubular body portions 76 C, 78 C which project externally of the clutch members, as shown in FIG. 19 .
During assembly, the steel rod seat frame segment 30 A is inserted into the bore 76 B of the tubular steel coupling sleeve 76 , and is then welded to the tubular steel coupling sleeve. Likewise, the steel rod seat frame segment 32 A is inserted into the bore 78 B tubular steel coupling sleeve 78 and then is also welded to the tubular coupling sleeve. This arrangement facilitates assembly of the buoyant lounge chair, and provides a more reliable water-tight seal around the chair frame segments that are subject to corrosion. The weldment bead W between the chair frame segments and the tubular coupling sleeves, together with the embedded end portions 76 A, 78 A assure a permanent bond between the chair frame and each clutch member, and prevents separation of the back frame from the seat frame.
Referring now to FIG. 19, FIG. 20, FIG. 21 and FIG. 22, one end portion 76 A of the tubular steel coupling sleeve 76 is flattened or crimped with a swage tool, as shown in FIG. 20, which causes the end portion to be radially enlarged and flare radially outwardly from the tubular sleeve body portion 76 C. The radially enlarged end portion 76 A is totally embedded and molded within the clutch body 62 , thereby preventing twisting movement or axial movement of any kind of the tubular steel coupling sleeve with respect to the clutch body 62 , thus firmly locking it into place. After the steel rod seat frame segment 30 A is inserted into the cylindrical bore 76 B of the steel coupling sleeve 76 , as shown in FIG. 19, the two pieces are welded together by a weld bead W. The back frame segment 32 A is secured in a welded union W with a tubular steel coupling sleeve 78 which is identically formed with a radially enlarged, flared end portion 78 A. The result is a high strength union which can withstand rough handling without separation and is protected against corrosion.
Referring now to FIG. 23, an alternative lounge chair embodiment 100 includes an extended buoyant cushion portion 26 E that projects forward of and in cantilevered relation to the central seat frame segment 30 C. The extended length of the leg support section provides complete support for the swimmer's entire body, including his legs and feet, when the seat back 12 is set in the fully extended, body float position as shown in FIG. 10 . The lounge chair 100 shown in FIG. 12 is identical in construction with the lounge chair 10 shown in FIG. 1, except for the additional leg support length.
Although the invention has been described with reference to certain exemplary arrangements, it is to be understood that the forms of the invention shown and described are to be treated as preferred embodiments. Various changes, substitutions and modifications can be realized without departing from the spirit and scope of the invention as defined by the appended claims.
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A buoyant pool chair supports a swimmer in an upright, semi-reclining or sitting position while the chair is floating in a swimming pool. Interconnected rigid frame members collectively form an open chair frame including a seat frame, left and right arm frames attached to the seat frame, and a back frame pivotally coupled to the seat frame. The back frame can be manually rotated to a folded, minimum profile position in which the chair back overlaps the chair seat, for example for shipping and storage, and rotatable to an upright, fixed position to accommodate lounging in a semi-reclining or sitting position. Stop apparatus on the chair frame is engagable with one of the seat frame and the back frame for fixing the back frame in the upright position, and releasable therefrom to permit closing rotational movement of the back frame to the folded position.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a wafer cassette, and more particularly to a wafer cassette carrying wafers.
[0003] 2. Description of the Related Art
[0004] During a semiconductor manufacturing process, transportation of wafers is accomplished by a wafer cassette. Namely, multiple wafers are supported in the wafer cassette and transported thereby to predetermined process machines or destinations for subsequent processing.
[0005] Referring to FIG. 1A and FIG. 1B , a conventional wafer cassette 1 is composed of PP or PEEK and comprises two opposite support bars 11 and a plurality of separation plates 12 . The separation plates 12 are respectively connected to the support bars 11 and parallel to and separated from one another. When the wafer cassette 1 carries a plurality of wafers (not shown), the wafers are respectively separated by the separation plates 12 and supported by the support bars 11 .
[0006] As shown in FIG. 1B , as the support bars 11 provide a strip-like construction, linear contact exists between the wafers and the support bars 11 . Specifically, when a wafer W is vertically placed into the wafer cassette 1 from the top thereof and pulled downward by gravity, as shown in FIG. 2 , linear impact (shown by area A) is generated between the wafer W and the support bars 11 with the strip-like construction. Here, as the hardness of the wafer W exceeds that of the support bars 11 composed of PP or PEEK and a large contact stress (such as 16.943 kgw/mm 2 obtained from an experimental result) is generated due to a small contact area between the wafer W and the support bars 11 with the strip-like construction, the support bars 11 are easily damaged by impact and wear, causing cassette particles. The cassette particles from the support bars 11 then fall onto the surfaces of the wafers or process machines during transportation of the wafer cassette 1 and wafers, thus causing damage to the wafers during subsequent processing. For example, if the cassette particles fall onto the top surface of a wafer, partial circuits cannot be laid on dies of the wafer by obstruction of the cassette particles when the dies are subjected to an exposure process, thereby causing die deficiency at the related pattern exposure areas. In another aspect, if cassette particles fall onto the bottom surface of a wafer, exposure areas protrude from the wafer due to the cassette particles when the bottom surface of the wafer is attached to a flat wafer chuck, causing local defocus of the exposure areas, and further causing die deficiency at the related pattern areas.
[0007] Moreover, as the large contact stress generated between the wafer W and the support bars 11 with the strip-like construction can be further transmitted to the center or other portions of the wafer W, metal conducting wires on dies of the wafer W are easily broken by the presence of the large contact stress, causing deficiency of the dies.
[0008] Hence, there is a need for a wafer cassette utilizing a special composite curved holding portion to support wafers. A contact stress between the composite curved holding portion and the wafers is effectively reduced, significantly reducing the amount of cassette particles produced, and further enhancing overall process yield of the wafers.
BRIEF SUMMARY OF THE INVENTION
[0009] A detailed description is given in the following embodiments with reference to the accompanying drawings.
[0010] An exemplary embodiment of the invention provides a wafer cassette comprising at least one support bar and a plurality of separation plates. The support bar comprises a composite curved holding portion. The separation plates are connected to the composite curved holding portion and are parallel to and separated from each other.
[0011] The composite curved holding portion comprises a first curved surface, a second curved surface, and a third curved surface. The second curved surface connects the first curved surface to the third curved surface.
[0012] The direction of curvature of the second curved surface is opposite to that of the first curved surface. The direction of curvature of the third curved surface is the same as that of the first curved surface.
[0013] The first, second, and third curved surfaces comprise a plurality of round surfaces, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
[0015] FIG. 1A is a schematic perspective view of a conventional wafer cassette;
[0016] FIG. 1B is a schematic top view of FIG. 1A ;
[0017] FIG. 2 is a schematic partial cross section and side view of the conventional wafer cassette carrying a wafer;
[0018] FIG. 3A is a schematic perspective view of a wafer cassette of an embodiment of the invention;
[0019] FIG. 3B is a schematic top view of FIG. 3A ;
[0020] FIG. 4 is a schematic partial cross section and side view of a wafer cassette of an embodiment of the invention; and
[0021] FIG. 5 is a schematic partial cross section and side view of a wafer cassette, of an embodiment of the invention, carrying a wafer.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
[0023] Referring to FIG. 3A and FIG. 3B , a wafer cassette 100 may be composed of PP or PEEK and comprises two opposite support bars 110 and a plurality of separation plates 120 .
[0024] As shown in FIG. 3B , each support bar 110 comprises a composite curved holding portion 111 . Specifically, as shown in FIG. 4 , each composite curved holding portion 111 comprises a first curved surface 111 a, a second curved surface 111 b, and a third curved surface 111 c. The second curved surface 111 b connects the first curved surface 111 a to the third curved surface 111 c. More specifically, the direction of curvature of the second curved surface 111 b is opposite to that of the first curved surface 111 a, and the direction of curvature of the third curved surface 111 c is the same as that of the first curved surface 111 a. In this embodiment, the profiles of the first curved surface 111 a, second curved surface 111 b, and third curved surface 111 c are designed by means of the finite element method, and the first curved surface 111 a, second curved surface 111 b, and third curved surface 111 c thus comprise a plurality of round surfaces, respectively.
[0025] As shown in FIG. 3B , the separation plates 120 are respectively connected to the composite curved holding portions 111 of the support bars 110 and are parallel to and separated from each other. When the wafer cassette 100 carries a plurality of wafers (not shown), the wafers are respectively separated by the separation plates 120 and supported by the composite curved holding portions 111 of the support bars 110 .
[0026] Accordingly, as the composite curved holding portions 111 of the support bars 110 are designed by a special manner, surface contact exists between the wafers and the composite curved holding portions 111 . Specifically, when a wafer W is vertically placed into the wafer cassette 100 from the top thereof, as shown in FIG. 5 , large-area contact (shown by area B) is generated between the wafer W and the composite curved holding portions 111 . More specifically, by the special design of the first curved surface 111 a, second curved surface 111 b, and third curved surface 111 c, a fixed large contact area (such as an optimal contact area of 13 mm×0.75 mm obtained from experimental results) can be maintained between the wafer W and the composite curved holding portions 111 , such that the wafer W is always subjected to minimal stress when contacting the composite curved holding portions 111 . Accordingly, as a reduced contact stress (such as 13.617 kgw/mm 2 obtained from an experimental result) is generated due to an increased contact area between the wafer W and the composite curved holding portions 111 , cassette particles are not easily generated by wear of the composite curved holding portions 111 even though the hardness of the wafer W exceeds that of the composite curved holding portions 111 composed of PP or PEEK. Thus, during transportation of the wafer cassette 100 and wafers, the amount of the cassette particles from the composite curved holding portions 111 is significantly reduced, effectively preventing deficiency of the wafers during subsequent processing.
[0027] Moreover, because reduced contact stress is generated between the wafer W and the composite curved holding portions 111 due to the optimal contact area, the reduced contact stress is not easily transmitted to the center or other portions of the wafer W, thereby preventing breakage of metal conducting wires on dies of the wafer W by the presence of the stress, and further enhancing yield of the dies of the wafer W.
[0028] In conclusion, as the disclosed wafer cassette effectively provides a reduced contact stress between the composite curved holding portions (or support bars) and the wafers, the amount of the cassette particles is significantly reduced, thus enhancing overall process yield of the wafers.
[0029] While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
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A wafer cassette. At least one support bar includes a composite curved holding portion. Multiple separation plates are connected to the composite curved holding portion and are parallel to and separated from each other.
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FIELD OF THE INVENTION
The invention relates to an apparatus and a method for determining an approximate value for the stroke volume and the cardiac output of a person's heart. The apparatus and method employ a measured electrical impedance, or admittance, of a part of a person's body, namely, the thorax. This part of a person's body is chosen because its electrical impedance, or admittance, changes with time as a consequence of the periodic beating of the heart. Accordingly, the measured electrical admittance or impedance can provide information about the performance of the heart as a pump.
RELATED PRIOR ART
In 1966, Kubicek et al. were the first to design a clinically applicable device, capable of determining the stroke volume (SV) by non-invasive, electrical means. The Kubicek method is disclosed in the article by Kubicek et al., Development and Evaluation of an Impedance Cardiac Output System, Aerospace Medicine 1966, pp 1208-1212, and in U.S. Pat. No. 3,340,867 which are both incorporated herein by reference. (see also U.S. Pat. No. 5,178,154 to Ackmann et al, U.S. Pat. No. 5,316,004 to Chesney et al, U.S. Pat. No. 4,953,556 to Evans, U.S. Pat. No. 5,685,316 to Schookin et al, U.S. Pat. No. 5,505,209 to Reining, U.S. Pat. No. 5,529,072 to Sramek, U.S. Pat. No. 5,503,157 to Sramek, U.S. Pat. No. 5,469,859 to Tsoglin et al, U.S. Pat. No. 5,423,326 to Wang et al, and U.S. Pat. No. 5,309,917 to Wang et al.)
When a tetrapolar array of circumferential band electrodes is placed at the base of the neck and about the circumference of the lower chest, at the level of the xiphoid process, and a constant magnitude alternating current (AC) is injected through the upper cervical and lower thoracic band electrodes, a voltage, proportional to the thoracic electrical impedance (or reciprocally proportional to the admittance), is measured between the inner cervical and thoracic band electrodes. The portion of the cardiac synchronous impedance change, ΔZ(t), temporally concordant with stroke volume, was ascribed solely and uniquely to volume (plethysmographic) changes of the aorta during expansion and contraction over the heart cycle.
In the article by Woltjer H. H. et al. (The technique of impedance cardiography. Eur Heart J 1977; 18: 1396-1403), the Kubicek model is explained as follows. The aorta is considered a cylinder of length L, equal to the distance between the voltage sensing electrodes. The thorax, exclusive of the aorta, is considered a cylinder of length L, equal to aortic length, and of cross-sectional area (CSA), equal to the cross-sectional area of the thorax measured at the xiphoid level. The blood-filled aorta is assumed to have a constant specific electrical resistance equal to that of stationary blood, ρ. The thoracic encompassing cylinder is assumed to be homogeneously perfused with blood of specific resistance ρ. The aorta and the thoracic encompassing cylinder are assumed to be analogous to parallel electrical conductors.
It was accepted by Kubicek that, according to Nyboer (J. Electrical impedance plethysmography. A physical and physiologic approach to peripheral vascular study. Circulation 1950; 2: 811-821), the portion of ΔZ(t), temporally concordant with SV, represented simultaneous inflow and outflow of blood over the systolic portion of the heart cycle. Thus, determining the area underneath the systolic portion of ΔZ(t) was assumed not to represent net volume inflow across the aortic segment under electrical interrogation. Thus, an extrapolation procedure was proposed, utilizing the maximum forward systolic slope of ΔZ(t). In order to compensate for aortic outflow, the maximum forward slope, analogous to peak flow, was stipulated to be constant throughout the systolic ejection interval. The maximum forward systolic upslope represents the peak, or maximum rate of change of impedance, i.e. ( Z ( t ) t ) MAX .
Instead of measuring the slope directly, as proposed by Nyboer, Kubicek electronically differentiated ΔZ(t) into dZ(t)/dt. Thus, the peak systolic magnitude of dZ(t)/dt is ( Z ( t ) t ) MAX .
In order to derive stroke volume (SV), Kubicek multiplied the peak rate of change of impedance by systolic flow time of the left ventricle, T LVE .
According to Kubicek SV = V eff · ( Z ( t ) t ) MAX Z 0 · T LVE = ρ L 2 Z 0 · ( Z ( t ) t ) MAX Z 0 · T LVE ,
wherein Z 0 is the quasi-static portion of the measured impedance Z, and wherein ( Z ( t ) t ) MAX
is the peak value of the (inverted) first time-derivative of ΔZ(t), which corresponds to the maximum forward systolic upslope of ΔZ(t). Note that in this context, by peak magnitude, the maximum absolute amplitude is stipulated. In fact, during systole, the impedance decreases such that the sign of ΔZ(t) is negative. Hence, correctly stated, ( Z ( t ) t ) MAX
is the minimum of the time-derivative of ΔZ(t), i.e. ( Z ( t ) t ) MIN .
Furthermore, in the above formula, T LVE is the left ventricular ejection time, i.e. the time between opening and closure of the aortic valve, also referred to as systolic flow time. The volume V EFF = ρ · L 2 Z 0
is the volume of electrically participating thoracic tissue (VEPT), wherein ρ is the specific resistance of stationary blood, which Kubicek assumed to be 150 Ωcm, and L is the distance between the voltage-sensing electrodes which are applied to the neck and thorax.
By virtue of rigid theoretical constraints, the Kubicek method, and its derivatives, consider volume changes in the aorta, i.e. plethysmographic changes, to be the sole contributor to ( Z ( t ) t ) MAX .
Consequently, ΔZ(t) is assumed to represent the time-variable volumetric expansion and recoil of the aorta. Thus, its time-derivative, dZ(t)/dt, represents an ohmic equivalent of the rate of change of aortic volume. This would also imply that ( Z ( t ) t ) MAX ,
measured in [Ω/s], is directly proportional to peak flow [mL/s] and peak velocity [cm/s].
It is widely believed that the assumptions made in the Kubicek model are generally valid, i.e. that the increased aortic volume during mechanical systole leads to the decrease in the thoracic impedance. Since Kubicek assumed a directly proportional, i.e. linear, relationship between SV and ( Z ( t ) t ) MAX
times T LVE , it is usually believed that ( Z ( t ) t ) MAX
is analogous and proportional to peak flow, or peak rate of change of aortic volume. Therefore, subsequent improvements focused only on a better definition and modeling of V EFF .
For example, Sramek developed a formula according to which V EFF = L 3 4.25
(see U.S. Pat. No. 4,450,527 which is incorporated herein by reference).
In a later iteration, Sramek approximated L as 17% of the person's height h. Thus, Sramek proposed the equation SV = ( 0.17 h ) 3 4.25 · ( Z ( t ) t ) MAX Z 0 · T LVE
Bernstein (Bernstein D. P., A new stroke volume equation for thoracic electrical bioimpedance. Crit Care Med 1986; 14: 904-909) introduced a factor δ accounting for the person's weight deviation from ideal (as determined from the Metropolitan Life Insurance tables), corrected for blood volume, normalized to deviation from ideal body weight. Otherwise, Sramek's model remained unchanged, and Bernstein proposed the formula SV = δ · ( 0.17 h ) 3 4.25 · ( Z ( t ) t ) MAX Z 0 · T LVE
Despite these various efforts for improving the determination of the stroke volume, the stroke volume could not be correctly predicted across a wide range of subjects in health and disease.
In particular, in the following cases, the Sramek-Bernstein equation generally results in an overestimation of the true predicted stroke volume: children and healthy young adults; underweight individuals; tall, thin adults.
According to Spiering et al (Comparison of impedance cardiography and dye dilution methods for measuring cardiac output. Heart 1998; 79: 437-441), the use of the Sramek-Bernstein equation generally results in an underestimation of the true predicted stroke volume in the following cases: elderly adults, obese individuals; individuals with sepsis, acute lung injury or pulmonary edema; and during exercise.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide apparatus and method that determines the stroke volume accurately for individuals of all ages in health and disease states.
The invention considers the absolute peak rate of change of impedance, ( Z ( t ) t ) MIN ,
to be the ohmic equivalent of peak aortic blood acceleration [mL/s 2 ], or peak rate of change of aortic blood velocity. As a consequence, ΔZ(t), in earliest systole, is related to hemorheologic (blood flow) changes, not plethysmographic (volume) changes. Thus, the new apparatus can be described as an ‘electrical velocimeter’, or the method incorporated as ‘electrical velocimetry’.
Consequently, the measured value of ( Z ( t ) t ) MIN
cannot be implemented directly into SV calculation. Theoretically, ( Z ( t ) t ) MIN
must be integrated in order to obtain an ohmic equivalent for blood velocity. In summary, the invention mandates that the part of the previous art related to ( Z ( t ) t ) MIN Z 0
be changed.
Hence, the apparatus and method according to the invention employ no underlying modeling or theoretical assumptions of the Kubicek, or any other subsequent, plethysmographic approaches.
According to theory derived from basic science (and published as Sakamoto K, Kanai K. Electrical characteristics of flowing blood. IEEE Trans Biomed Eng 1979; 26: 686-695; Visser K R. Electrical properties of flowing blood and impedance cardiography. Ann Biomed Eng 1989; 17: 463-473; Lamberts R et al. Impedance cardiography. Assen, The Netherlands: Van Gorcum 1984; 84-85; and Matsuda Y et al. Assessment of left ventricular performance in man with impedance cardiography. Jap Circ J 1978; 42: 945-954 ), the change of blood resistivity, and the rate of change of blood resistivity, can be normalized for corrected flow time, FTC, FT C = T LVE T RR m ,
where T LVE equals the left-ventricular ejection time (known also as systolic flow time), divided by a root of T RR , where T RR equals the value for the RR interval (cycle time) in seconds.
With V EFF defined as the effective volume of electrical participating thoracic tissue ([V EFF ]=ml), the stroke volume SV, according to the invention, is calculated according to the formula SV = V EFF · C 1 ( ( Z ( t ) t ) MIN Z 0 ) n · ( 1 T RR ) m · T LVE
with 0.15<n<0.8 and 0≦m≦1.5, and wherein C 1 is a constant which is necessary if n+m≠1 in order to adjust the units of the measured values in the formula such that the stroke volume is obtained in milliliters. C 1 need not have a numerical value different from 1.
A preferred case is that n=1−m. Then, C 1 =1.
The most preferred case is n=m=0.5. Then, FT C = T LVE T RR .
Other objects, features and advantages of the invention will become apparent from the following description of a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram depicting the apparatus, which uses on a subject's left and right side of the thorax, each, a tetrapolar surface electrode array, an alternating current (AC) source and a voltmeter.
FIG. 2 is a schematic diagram depicting the apparatus of FIG. 1, but limiting the measurement to the left side of the subject's thorax only.
FIG. 3 is a schematic diagram depicting the apparatus of FIG. 2, using a tetrapolar surface electrode array across the subject's thorax.
FIG. 4 is a schematic diagram depicting the apparatus of FIG. 1, but utilizing a common AC source for left and right side of the subject's thorax.
FIG. 5 is a schematic diagram illustrating the application of an esophageal catheter/probe for determining SV by measurement of esophageal electrical bioimpedance (or bioadmittance).
FIG. 6 is a diagram showing the variation of thoracic impedance with a ventilation cycle and with each heart beat.
FIG. 7 is a diagram showing the variation of thoracic impedance with each heart beat when ventilation is suppressed.
FIG. 8 is a diagram showing curves representing a surface electrocardiogram, the time-varying portion of the cardiogenic thoracic electrical impedance, ΔZ(t), and the time-derivative of this varying portion of the impedance, dZ(t)/dt.
FIG. 9 is a block diagram of the apparatus of the present invention with details of the different components of the apparatus;
FIG. 10 is the block diagram of FIG. 9 in which the Digital Signal Processor is shown in less detail whereas the Microprocessor is shown in more detail.
DETAILED DESCRIPTION OF THE INVENTION
Principally, an alternating electrical field is applied to a thoracic volume forcing an alternating current (AC) to flow in parallel to the direction of aortic blood flow, i.e. vertically between neck and lower thorax. The current of known magnitude causes, in the direction of the electrical field, a voltage drop, which is proportional to the product of thoracic impedance and current applied.
FIG. 1 schematically shows an apparatus according to the present invention, and its electrical interface with a subject 10 . For the measurement of transthoracic electrical bioimpedance (or bioadmittance), a tetrapolar surface electrode array (with electrodes 12 , 14 for AC application, and electrodes 16 , 18 for voltage sensing) is applied to the subject's left side, and another tetrapolar electrode array (with electrodes 20 , 22 for AC application, and electrodes 24 , 26 for voltage sensing) to the subject's right side.
The left sided electrode array includes two current electrodes 12 , 14 , which are connected to an AC Source L 28 , and two voltage sensing electrodes 16 , 18 , which are connected to Voltmeter L 30 . One voltage sensing electrode ( 16 ) is placed at the base of the neck, the other one ( 18 ) the lower thorax, at the level of the xiphoid process. The current electrodes ( 12 , 14 ) are placed respectively, in the vertical direction, above and below the voltage sensing electrodes ( 16 , 18 ).
The right sided electrode array includes two current electrodes 20 , 22 , which are connected to an AC Source R 32 , and two voltage sensing electrodes 24 , 26 , which are connected to Voltmeter R 34 . One voltage sensing electrode ( 24 ) is placed at the base of the neck, the other one ( 26 ) the lower thorax, at the level of the xiphoid process. The current electrodes ( 20 , 22 ) are placed respectively, in the vertical direction, above and below the voltage sensing electrodes ( 24 , 26 ).
AC Source L 28 and AC Source R 32 are voltage-controlled current sources (VCCS). Each VCCS provides an alternating current (AC), which is measured via Analog/Digital Converters 42 , 44 . Alternatively, the magnitude of the alternating current can be held constant, and the Analog/Digital Converters 42 , 44 can be omitted. A Digital/Analog Converter (DAC) 36 provides an output that controls the AC Source L 28 and AC Source R 32 . The Digital/Analog Converter (DAC) 36 itself is controlled by a Signal Synthesizer 38 . The Signal Synthesizer 38 is implemented via a lookup-table in the memory of a Digital Signal Processor 40 as part of a Processing Unit 80 (indicated by dashed lines). Alternatively, a Direct Digital Synthesizer (DDS, not shown) can provide the functions of DAC 36 and Signal Synthesizer 38 . The Processing Unit 80 recognizes AC magnitude and phase of each VCCS.
The voltages measured by the Voltmeters L 30 and R 34 do not only contain a signal caused by the AC applied, but also a signal component from which an electrocardiogram (ECG) can be derived. The application of filters separates the AC related and ECG related signal components. The AC related signal component is proportional to the product of current applied and the impedance (which is unknown). In the case that the currents applied are of constant magnitude, the voltage V L 46 obtained by voltmeter L 30 , and digitized by the analog/digital converter 48 , is directly proportional to the unknown impedance of the left hemi-thorax, Z L (t) (or reciprocally proportional to the unknown admittance, Y R (t)). With the AC magnitude held constant, the voltage V R 50 obtained by voltmeter R 34 , and digitized by the analog/digital converter 52 , is directly proportional to the unknown impedance of the right hemi-thorax, Z R (t) (or reciprocally proportional to the unknown admittance, Y R (t)). The Processing Unit 80 determines Z(t) by averaging Z L (t) and Z R (t), or Y(t) by averaging Y L (t) and Y R (t). Alternatively, the voltage V L 46 sensed between electrodes 16 and 18 (left side) and the voltage V R 50 sensed between the electrodes 24 and 26 (right side) can be summed, or averaged, prior to the voltmeters, requiring then only one analog/digital converter.
A demodulation of the AC related signal component is required in order to extract the impedance related information from the AC carrier signal. Demodulation of the voltages obtained from the thorax is described, for example, by Osypka and Schafer (Impedance cardiography: Advancements in system design. Proceedings of the X. International Conference on Electrical Bio-Impedance (ICEBI). Barcelona, Spain, Apr. 5-9, 1998), utilizing phase-sensitive detectors. With respect to FIG. 1, demodulation is an integral part of the voltmeters 30 , 34 . Alternatively, demodulation is performed by utilizing digital correlation technique, which is accomplished, for example, by the Digital Signal Processor 40 (Osypka et al. Determination of electrical impedances of tissue at a frequency range of 5 Hz to 20 KHz by digital correlation technique. Proceedings of the V. Mediterranean Conference on Medical and Biological Engineering (MEDICON). Patras, Greece, Aug. 29-Sep. 1, 1989).
Voltmeter L 30 also obtains the electrocardiogram (ECG) vector V BC , measured between the left-sided sensing electrodes 16 and 18 , which is digitized by an analog/digital converter 56 and fed to the Processing Unit 80 . Voltmeter R obtains the ECG vector V FG , measured between the right-sided sensing electrodes 24 and 26 , which is digitized by an analog/digital converter 60 and fed to the Processor Unit 80 .
It is understood that more ECG vectors can be obtained by paired combination of sensing electrodes between the left hemi-thorax ( 16 , 18 ) and the right hemi-thorax ( 24 , 26 ). The measurement of additional ECG vectors requires additional voltmeters and analog/digital converters (ADC) connected to the Processing Unit.
The Processing Unit automatically, or the operator manually, determines the most appropriate ECG vector, or superimposes several ECG vectors to achieve a resulting mean, or reference ECG 62 . Alternatively, the outputs of several voltmeters are fed into a separate multiplexer. The output of this multiplexer is controlled by the operator, or, automatically, by the Digital Signal Processor. Alternatively, the ECG obtained from an external ECG monitor can be used as the reference ECG 62 .
The Processing Unit 80 separates the quasi-constant base impedance, Z 0 , from the time-varying, cardiogenic change, ΔZ(t), or, if the admittance approach is used, the quasi-constant base admittance, Y 0 , from the time-varying, cardiogenic change, ΔY(t). Details of the subsequent processing applied are described below with respect to FIGS. 9 and 10.
The Processing Unit 80 in FIG. 1 is divided into a Digital Signal Processor 40 and a Microprocessor 66 . Here, the microprocessor 66 establishes the interface between the Digital Signal processor 40 and an operator. The functions described as being part of the Digital Signal Processor are not limited to the implementation in the Digital Signal Processor exclusively but may be implemented in the Microprocessor, or vice versa. Alternatively, the Processing Unit may consist of either a Digital Signal Processor or a Microprocessor.
The subject's weight, and other data, is entered via a keyboard 68 . Alternatively, data is entered via a touch-screen 70 , or via a digital interface 72 .
The stroke volume (SV) is calculated by the Processor Unit 80 according to the preferred formula SV = V EFF · ( Z ( t ) t ) MIN Z 0 · FT C ( 1 )
wherein FT C = T LVE T RR ,
and wherein the parameters used for this calculation are those which have been input via the keyboard 68 , the touch-screen 70 , the digital interface 72 or those which have been determined in the Processing Unit 80 as set out below with respect to FIGS. 6-10. The calculated stroke volume, in conjunction with related cardiovascular parameters, is then displayed on a numerical or graphical screen 70 . Alternatively, or in addition, it is transmitted via the data interface 72 .
The employment of a separate AC source for each tetrapolar electrode array allows measurement of the skin-electrode impedance, and, thus, monitoring of the skin-electrode contacts of the current electrodes related to this electrode array. The apparatus according to FIG. 1 has the capability to monitor skin-electrode contacts of the left and right hemithorax individually. Qualitatively, a comparator circuit (not shown) can determine whether or not the AC source is overloaded because, for example, of an infinite load (break of connection, loose electrode). Quantitatively, a voltmeter can be connected, or temporally switched, to the outputs of the AC source. The voltmeter measures the voltage across the skin-electrode interfaces and the thorax. The impedance recognized by the AC source is determined as the ratio of the voltage measured and the known AC current applied.
FIG. 2 schematically shows an alternative embodiment of the apparatus according to the present invention. This embodiment is identical with the apparatus as described with respect to FIG. 1, but with the exception that only a single AC source 28 , a single Voltmeter 30 and a single tetrapolar surface electrode array are employed. AC Source L 28 is connected to the current electrodes 12 and 14 , and Voltmeter L 30 , connected to the sensing electrodes 16 and 18 . By employing a single electrode array alone (in FIG. 2 the left-sided electrode array), the surface ECG vector V BC 54 is available.
FIG. 3 schematically shows a further embodiment of the apparatus according to the present invention. This embodiment is identical with the apparatus described with respect to FIG. 2, but with the exception that the tetrapolar electrode array is applied across the thorax. AC Source L 30 is connected to the current electrodes 20 and 14 , and Voltmeter L 30 , connected to the sensing electrodes 24 and 18 . By employment of the cross-thoracic electrode array alone, the surface ECG vector V FC 54 is available.
FIG. 4 schematically shows an alternative embodiment of the apparatus according to the present invention. This embodiment is identical with the apparatus described with respect to FIG. 1, but with the exception that only one AC source, AC Source L 28 , is employed, and interfaced, in parallel, to the current electrodes 12 , 14 of the left sided and to the current electrodes right sided electrode array, 20 , 22 . The capability of the apparatus as shown in FIG. 4 to monitor skin-electrode contact for the current electrodes for left and right sides individually, is compromised, with respect to FIG. 1 .
Though the above description was related to the measurement of the impedance (or admittance) of the patient's thorax utilizing surface electrodes, the apparatus and method according to the invention are not restricted to this application. In particular, it is also possible to insert electrodes located on a catheter/probe into the esophagus of a patient. FIG. 5 schematically shows a further embodiment of the apparatus according to the present invention. This apparatus is identical to the apparatus as described with respect to FIG. 2, but utilizing a tetrapolar electrode array located on an esophageal catheter/probe. AC Source L 28 is connected to the current electrodes, and Voltmeter L 30 is connected to the sensing electrodes. The esophageal ECG vector V ES and the esophageal impedance signal V E are obtained from the voltage sensing electrodes. The impedance (or admittance) changes as a result of the pulsatile vessel flow can be measured.
If the apparatus shown in FIG. 5 is used, principally, the stroke volume can be calculated according to formula (1) given above, wherein coefficients and exponents, and the given implementation of mZ {overscore (T)} as described below have to be adapted. The use of electrodes inserted into the esophagus is, for example, disclosed in U.S. Pat. No. 4,836,214, which is incorporated herein by reference.
In the following, it is described how the various parameters used in formula (1) above are obtained.
FIG. 6 illustrates the variation of thoracic impedance with a ventilation cycle and with each heart beat. The electrocardiogram (ECG) on top is a reference for the impedance changes related to the cardiac cycle. The major part of thoracic impedance, the base impedance, Z 0 , is obtained as the moving average of measured thoracic impedance over a period of, for example, 5 seconds. In a normal healthy subject, Z 0 is approximately 30Ω, and does not change from beat to beat. Superimposed on Z 0 are changes in impedance (ΔZ) corresponding to both respiration (ΔZ RESP ) and pulsatile blood flow (ΔZ CARD ). The total thoracic impedance at any time thus equals:
Z ( t )= Z 0 +ΔZ ( t )= Z 0 +ΔZ RESP ( t )+Δ Z CARDIAC ( t ).
In FIG. 6, the respiration cycle begins with maximal inspiration, where air in the lungs causes an increase in thoracic impedance, compared to the base impedance, Z 0 . During expiration, the ratio of air to liquid in the thorax decreases, as does the thoracic impedance.
If respiration is suppressed, or the corresponding effect on the impedance (or admittance) signal is filtered out, only the cardiac-induced pulsatile impedance component, ΔZ CARDIAC , remains (FIG. 7 ). For simplicity, in the following, ΔZ is referred to the cardiac-induced impedance change, that is, the impedance change due to ventricular ejection, ΔZ CARDIAC .
FIG. 8 contains parallel tracings of a scalar surface electrocardiogram (ECG) 100 , the thoracic cardiogenic impedance pulse, ΔZ(t) 102 , and the rate of change of thoracic impedance, dZ(t)/dt 104 .
The sequential, nearly synchronous, electrical depolarization of the atrial and ventricular heart muscle chambers can be electrically sensed and displayed, and the electrical waveform is characterized, by accepted convention, as the ‘PQRST’ complex within the ECG tracing. The ‘PQRST’ complex includes the P-wave, corresponding to the atrial depolarization wave, the Q-wave (labeled ‘Q’), corresponding to depolarization of the inter-ventricular septum, the R-wave (labeled ‘R’), corresponding to ventricular chamber muscle depolarization, and the T-wave, which represents the repolarization of the ventricular myocardial cells.
The R wave is determined, for example, by continuously obtaining the ECG signal amplitude and, by processing its first time-derivative, its slope. In the event that the absolute slope of the ECG signal exceeds a certain threshold, the ECG Processor 62 establishes a time window, within which the detected absolute peak of the ECG signal represents the temporal occurrence of the R wave.
The time interval between two consecutive R waves is defined as the R-R interval (T RR , FIG. 8 ). In the apparatus according to the preferred embodiment, the R-R interval represents the cardiac cycle period. However, alternatively, other intervals such as, for example, the Q-Q interval can be used to determine the cardiac cycle period within the scope of the invention.
The R wave peak magnitude of each ‘PQRST’ complex serves as the temporal reference for the processing of ΔZ(t) and dZ(t)/dt. The point Q precedes the peak R wave by approximately 50 ms and is referred to as the onset of electromechanical systole. The time interval between point Q and the opening of aortic valve (point labeled ‘B’) is known as the pre-ejection period, T PE . The time interval between point B and the closure of the aortic valve (point labeled ‘X’) is defined as left-ventricular ejection time, T LVE . The point labeled ‘C’ indicates the maximal rate of decrease of impedance, i.e. a minimum of dZ(t)/dt. The nadir of dZ(t)/dt at this point in time is further referred to as ( Z ( t ) t ) MIN .
The point labeled ‘Y’ represents the temporal occurrence of pulmonic valve closure. The point labeled ‘O’ occurs in diastole and is known to correspond to the early phase of rapid ventricular filling.
The value of T LVE can be automatically determined by a computer analysis in which predetermined criteria are used. The criterion for the determination of point B is the steep decrease of dZ(t)/dt afterwards, whereas point X is the first peak of dZ(t)/dt following ( Z ( t ) t ) MIN .
The determination of these two points of interest is, hence, easy to perform by someone skilled in the computer art. The latter automatic method is illustrated in FIG. 9 by the means for determining T LVE 218 as part of the Processing Unit ( 80 ) and, more specifically, of the Signal Processor ( 40 ). Alternatively, the value of T LVE can be determined manually by the operator and then, via the keyboard 68 , entered into computation.
The block diagram of FIG. 9 illustrates the acquisition of the ECG and the thoracic impedance Z(t), with emphasis, in particular, on the Digital Signal Processor (DSP) 40 as part of the Processing Unit 80 (indicated by dashed lines). The human subject 10 is shown schematically. The voltage controlled AC source 200 applies an alternating current I AC to the subject's thorax. The voltage controlling the current source is generated externally to the Processing Unit, or by a synthesizer 202 integrated into the Processing Unit (indicated by dashed line from 202 to 200 ). In the preferred embodiment, the AC source provides a current of constant magnitude, independent of load within reasonable limits. Then the AC magnitude must be made known to the Processing Unit 80 . In the event that the magnitude of the AC source is not constant, it must be measured and recognized by the Processing Unit, as indicated by the dashed arrow from 200 to 210 .
Because of I AC applied to the thorax, a voltmeter 204 can measure the voltage U AC . This voltage contains the signal proportional the applied AC and the (unknown) thoracic impedance carrier signal, modulated on a carrier frequency, and the ECG signal obtained between the sensing electrodes. Within the voltmeter 204 , filters are utilized to separate the ECG signal from the applied AC related signal.
The ECG signal is the input to an ECG unit 62 , which determines the ECG signal used for temporal reference for the impedance processing. Alternatively, or in addition, the ECG can be recorded and processed by a source 206 separate and external to the apparatus described herein (indicated by dashed arrows from 10 via 206 to 62 ). An apparatus 208 determines the RR interval, T RR , from the reference ECG 100 (see also FIG. 6) provided by the ECG processing unit 62 . Alternatively, T RR can be determined as the time interval between two consecutive occurrences of ( Z ( t ) t ) MIN ,
which approximates T RR (indicated in FIG. 8 and, by a dashed line at 230 , in FIG. 9 ). In an alternative embodiment of the invention, the units 62 and 208 are not part of the processing unit 80 but are external devices.
The voltmeter 204 eliminates, by demodulation, the AC carrier frequency from the portion of U AC corresponding to the applied AC. The apparatus 210 determines the impedance Z(t) by calculating the ratio of voltage obtained and alternating current I AC applied: Z ( t ) = U ( t ) I ( t ) .
A low-pass filter (LPF) 212 is applied to Z(t) in order to obtain the base impedance, Z 0 . A high-pass filter (HPF) 214 is applied to Z(t) in order to obtain the thoracic cardiogenic impedance pulse, ΔZ(t) 102 (see also FIG. 6 ). The purpose of the high-pass filter is also to eliminate impedance changes due to pulmonary ventilation (respiration). A differentiator 216 determines the first time-derivative, or slope of ΔZ(t), that is, dZ(t)/dt. It is also referred to as the rate of change of thoracic impedance 104 (see also FIG. 6 ).
With reference to FIG. 6 : The dZ(t)/dt signal 104 exhibits characteristic landmarks, as described. The left-ventricular ejection time T LVE is determined from the dZ(t)/dt signal. Applying basic curve mathematical discussion, one skilled in the art can identify the temporal occurrence of aortic valve opening, point B (see arrow), as the “notch” just before the steep down-slope of dZ(t)/dt (after the R wave, but prior the point C). Aortic valve closure, labeled as point X and pointed to with an arrow, corresponds to a dZ(t)/dt peak after point C. The digital signal processor (DSP) 40 obtains these points B, C and X, automatically from a processing unit 218 (FIG. 7 ). This unit determines T LVE as the time interval between point B and point X.
Turning back to FIG. 9, a peak detector 220 is applied to the dZ(t)/dt signal 104 in order to obtain the peak rate of change of impedance during systole, see point C in FIG. 7, and its occurrence in time. The ECG provided by unit 62 is utilized as a temporal reference. The output of the peak detector, relevant for the SV determination, is the absolute peak rate of change of impedance, ( Z ( t ) t ) MIN .
The left-ventricular ejection time, T LVE , the RR interval, T RR , the base impedance, Z 0 , and the absolute peak rate of change of impedance, ( Z ( t ) t ) MIN ,
are furthermore transferred to the microprocessor (μP) 66 . The μP 66 determines from the parameters, measured and processed by the DSP 40 , and other parameters entered, for example, via the keyboard 68 (specifically: weight) the stroke volume (SV). The display 70 connected with the μP 66 illustrates the SV and the values of other related cardiodynamic parameters. Alternatively, a touch screen can be implemented instead of a display, enabling the operator to enter weight and other demographic data via the screen. The μP 66 can receive data obtained by other, external devices, for example, T RR and/or T LVE , through a data interface 72 , or send data to other, external devices, such as patient monitors.
The block diagram of FIG. 10 illustrates the acquisition of the ECG and the thoracic impedance Z(t), with emphasis, in particular, on the microprocessor (μP) 66 . The μP 66 receives the value for Z 0 from the DSP 40 . A unit 300 calculates the reciprocal of Z 0 , which is then multiplied 302 with the value of ( Z ( t ) t ) MIN
received from the DSP. This product is applied to unit 304 , which determines the square root. The result equals ( Z ( t ) t ) MIN Z 0 ,
which is an integral input for the SV calculation.
The μP utilizes the value for Z 0 to determine the index of transthoracic specific impedance 308 , further referred to as mZ {overscore (T)} . This index reflects the presence or absence of abnormal lung water, and is within the scope of the invention. mZ {overscore (T)} relates to the magnitude or degree of abnormal shunting or bypassing of applied AC around the V EFF , via additional abnormal conductive pathways. The critical level of base impedance is defined as Z C , where Z C is greater than 15Ω and less than 25Ω, i.e. 15Ω<Zc<25Ω. In the preferred embodiment, Z C =20Ω (Critchley L A H et al. The effect of lung injury and excessive lung fluid on impedance cardiac output measurements in the critically ill. Intensive Care Med 2000; 26: 679-685; Critchley L A H et al. Lung fluid and impedance cardiography. Anesthesia 1998; 53: 369-372; Shoemaker W C et al. Multicenter study of noninvasive systems as alternatives to invasive monitoring of acutely ill emergency patients. Chest 1998; 114: 1643-1652; Shoemaker W C et al. Multicenter trial of a new thoracic electrical bioimpedance device for cardiac output estimation. Crit Care Med 1994; 22: 1907-1912).
In the normal cardiopulmonary state, indicated by Z 0 ≧Z C , mZ {overscore (T)} equals 1. In the abnormal cardiopulmonary state, i.e. in the presence of excess thoracic liquids (Z 0 <Z C ), mZ {overscore (T)} is less than 1 and greater than 0, i.e. 0<mZ {overscore (T)} <1, and is calculated accordingly: mZ T _ = Z C 2 - Z C Z 0 + C 2 2 Z C 2 + Z 0 2 - 3 Z C Z 0 + C 2 .
C 2 is a constant and, in the preferred embodiment, taken to 0. In a simplified version of the invention, mZ {overscore (T)} is taken to be 1 for all values of Z 0 .
A unit 310 calculates the reciprocal value of mZ {overscore (T)} , or a power of it. The output of 310 is multiplied in unit 312 with the output of a unit 314 that calculates the mass-based volumetric equivalent of thoracic blood volume in the stable, normal cardiopulmonary state. Unit 314 requires the input of the weight of the subject 10 under investigation (indicated by the dashed line at 316 ). In the preferred embodiment, weight is entered via the keyboard 68 or the touch screen 70 . Alternatively, the value for weight is entered elsewhere and received via a data interface 72 (indicated by dashed line at 318 ) . The output of the multiplier 312 is V EFF , with V EFF = C 3 · W X mZ T _ N ,
where C 3 is taken to be 13, but can alternatively have any other value in a range of 0,01-15. In the case of the embodiments shown in FIGS. 1-4, C 3 is preferably comprised in the range of 11-15. In the case of the embodiment shown in FIG. 5, C 3 is preferably comprised in the range of 0.01-2.00. In the preferred embodiment, the exponent for weight, X, is taken to be 1.025. with its limits otherwise being 0.9-1.1, which are extrapolated from data presented in the article by Holt et al. with the title “Ventricular volumes and body weight in mammals”, Am.J.Physiol. 1968; 215:704-715. In the preferred embodiment, the exponent for mZ {overscore (T)} , N, is taken to be 1.5, with its limits otherwise being 1.0-2.0.
V EFF is, according to the model used here, the mass-based volumetric equivalent of the thoracic blood volume in the stable, normal state. V EFF also represents the total thoracic liquids in unstable cardiopulmonary disease states. These conditions are characterized by the abnormal presence of excess thoracic liquids. In the articles by Critchley et al. (Lung fluid and impedance cardiography. Anesthesia 1998; 53: 369-372; The effect of lung injury and excessive lung fluid on impedance cardiac output measurements in the critically ill. Intensive Care Med 2000; 26: 679-685) and Shoemaker et al. (Multicenter trial of a new thoracic electrical bioimpedance device for cardiac output estimation. Crit Care Med 1994; 22: 1907-1912; Multicenter study of noninvasive systems as alternatives to invasive monitoring of acutely ill emergency patients. Chest 1998; 114: 1643-1652) the impact of excess thoracic liquids related to SV determination by means of electrical bioimpedance have been observed.
The volume V EFF , determined as V EFF = C 3 · W X mZ T _ N ,
is an integral part of the preferred embodiment and the new SV equation proposed within. With proper scaling, other volumes such as, for example, the ones defined by Sramek and Bernstein, based on weight deviation from ideal weight and height, can be used instead. Employment of other volumes is at the expense of accuracy over a wide spectrum of subjects, because of their body habita and disease states.
The DSP 40 provides the measured values for the left-ventricular ejection time, T LVE , and the RR interval, T RR . Alternatively, T LVE can be manually entered via the keyboard 68 (indicated by dashed line at 320 ), or measured, or entered elsewhere and transmitted via a data interface 72 (indicated by dashed line at 322 ).
Alternatively, T RR can be manually entered via a keyboard 68 (indicated by dashed line at 324 ), or measured, or entered elsewhere and transmitted via a data interface 72 (indicated by dashed line at 326 ). Unit 328 determines the reciprocal value of T RR , which equals the human circulatory system frequency: f 0 = 1 T RR .
The circulatory frequency, f 0 , or its reciprocal, T RR , can be averaged for a plurality of periods. For example, these values can be averaged over the previous ten cardiac cycles (“moving average”).
Alternatively, the circulatory frequency, f 0 , can be entered manually by the operator trough the keyboard 68 , or transmitted via a data interface 72 .
The value for heart rate (HR, in beats per minute) is calculated by multiplying 334 the circulatory system f 0 with 60 .
Alternatively, the heart rate, HR, can be entered manually by the operator trough the keyboard 68 , or transmitted via a data interface 72 .
Unit 330 determines the square root. The output of unit 330 is the Bazett transformation (Bazett M C. An analysis of the time relations of electrocardiograms. Heart 1920, 7: 353-364), which, when multiplied in unit 332 with T LVE , normalizes T LVE for system mechanical frequency. This normalized T LVE , also known as corrected flow time, FT C , FT C = T LVE T RR ,
is an integral part of the preferred embodiment and the new SV equation proposed therewith. Other embodiments may use T LVE instead of FT C for the SV calculation, at the expense of accuracy at higher heart rates.
A multiplier 336 calculates the product of V EFF , ( Z ( t ) t ) MIN Z 0
and FT C , which equals the SV approximated by the apparatus ([SV]=mL): SV = V EFF · ( Z ( t ) t ) MIN Z 0 · FT C = V EFF · ( Z ( t ) t ) MIN Z 0 · T LVE T RR
The value of SV is displayed on a numerical or graphical screen 70 . Alternatively, or in addition, it can also be transmitted to a data interface 72 .
Cardiac output [L/min] is then calculated from SV [mL] as CO = SV T RR · 60 1000 .
The measured values can be averaged over a plurality of periods. For example, these values can be averaged over the previous ten cardiac cycles (“moving average”).
Although FIGS. 1-5 and 7 - 8 indicate that the majority of the functional units are implemented into a Processing unit, namely a signal processor and a microprocessor, part or all of the functions can be arranged as individual circuitries.
Furthermore, the approximation of SV according to this invention is not limited to the impedance method, but can be performed using the admittance approach. With Y ( t ) = 1 Z ( t ) ,
T 0 = 1 Z 0
and ( Y ( t ) t ) MAX ≅ 1 Z 0 2 · ( Z ( t ) t ) MIN ,
the SV is approximated according to SV = V EFF · ( Y ( t ) t ) MAX Y 0 · FT C .
With respect to the admittance approach, V EFF is determined by
V EFF =C 3 ·W X ·mY {overscore (T)} N ,
where C 3 is taken to be 13, but can alternatively have any other value in a range of 0.01-15. In the preferred embodiment, the exponent for weight, X, is taken to be 1.025, with its limits otherwise being 0.9-1.1. In the preferred embodiment, the exponent for mY {overscore (T)} , N, is taken to be 1.5, with its limits otherwise being 1.0-2.0.
The value for Y 0 is utilized to determine the index of transthoracic specific admittance, or conductivity, further referred to as mY {overscore (T)} . This index reflects the presence or absence of abnormal lung water, and is within the scope of the invention. mY {overscore (T)} relates to the magnitude or degree of abnormal shunting or bypassing of applied AC around the V EFF , via additional abnormal conductive pathways. The critical level of base admittance is defined as Y C , where Y C is greater than 0.04 Ω −1 (corresponding to 25Ω) and less than 0.0667 Ω −1 (corresponding to 15Ω), i.e. 0.04 Ω −1 <Y C <0.0667 Ω −1 . In the preferred embodiment, Y C =0.05 Ω −1 (corresponding to 20Ω).
In the normal cardiopulmonary state, indicated by Y 0 ≦Y C , mY {overscore (T)} equals 1. In the abnormal cardiopulmonary state, i.e. in the presence of excess thoracic liquids (Y 0 >Y C ), mY {overscore (T)} is greater than 1, i.e. mY {overscore (T)} >1, and is calculated accordingly: m Y T _ = 2 Y 0 2 + Y C 2 - 3 Y C Y 0 + C 2 Y 0 2 - Y C Y 0 + C 2 .
C 2 is a constant and, in the preferred embodiment, taken to 0. In a simplified version of the invention, mY {overscore (T)} is taken to be 1 for all values of Y 0 .
It is noted that, when electrical admittance is determined, instead of electrical impedance, the processing performed by the DSP 40 is similar. In this case, the DSP obtains the base admittance, Y 0 , after applying a low-pass filter to Y(t), which is the ratio of I AC 200 to U AC 204 : Y ( t ) = I ( t ) U ( t ) .
The application of a high-pass filter to ΔY(t) and a differentiator reveals the rate of change of cardiogenic admittance, dY(t)/dt. In fact, the dY(t)/dt signal appears, in approximation, as an inverted dZ(t)/dt waveform. In the case of the admittance approach, the peak detector determines the peak rate of change of admittance, ( Y ( t ) t ) MAX .
Other modifications and variations will become apparent to those skilled in the art in view of the above descriptions. The present invention is hence not limited to the preferred embodiment described above, but is only limited by the following claims.
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The invention relates to an apparatus and a method for determining an approximate value for the stroke volume and the cardiac output of a person's heart. The apparatus and method employ a measured electrical impedance, or admittance, of a part of a person's body, namely, the thorax. This part of a person's body is chosen because its electrical impedance, or admittance, changes with time as a consequence of the periodic beating of the heart. Accordingly, the measured electrical admittance or impedance can provide information about the performance of the heart as a pump.
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This application is a continuation of application Ser. No. 07/857,681, filed Mar. 25, 1992, now abandoned which is a continuation of Ser. No. 07/466,579, filed Jan. 17, 1990, now abandoned.
BACKGROUND TO THE INVENTION
This invention relates to fluid-pressure operated boosters for vehicle braking systems.
Known boosters for vehicle braking systems include a movable wall which applies a force to an output member, and the force exerted by the movable wall is augmented by fluid-pressure applied to the wall under the control of a mechanical valve operated by a pedal to energize the booster.
When the booster is pneumatically operated, chambers an opposite sides of the wall are normally subjected to equal fluid pressures, for example vacuum, through the open valve. Operation of the pedal first closes the valve to isolate the chambers from each other, and then operates the valve to admit fluid at a different pressure, suitably atmospheric air into one of the chambers, whereby to energize the booster by subjecting the movable wall to a differential pressure which augments the brake-applying force from the pedal.
When the booster is hydraulically-operated operation of the valve, suitably a spool valve, by the pedal causes hydraulic fluid under pressure, suitably from an hydraulic accumulator, to be admitted into a boost chamber, whereby to act on a boost piston, which comprises the movable wall, and energize the booster by pressurising the boost chamber.
It is known from EP-A-0 267 018 to control the operation of such known boosters independently of the pedal by the use of solenoid-operated valve means which are responsive to signals sensed by wheel speed sensors. This enables the brakes to be applied independently of the pedal to achieve traction control of a vehicle by applying the brake on a spinning wheel.
SUMMARY OF THE INVENTION
According to our invention, energization of a booster is controlled solely by operation of solenoid-operated valve means responsive to signals from an electronic controller.
The construction of the booster is therefore modified in comparison with known boosters by the omission of the conventional mechanical valve adapted to be operated by the pedal for normal operation of the booster.
The electronic controller receives signals from wheel speed sensors sensing the behaviour of the wheels and signals generated by operation of electrical means responsive to operation of the pedal, suitably an electrical switch, or a load cell.
Thus normal operation of the booster is initiated by pedal operation of the electrical means with the controller operating the solenoid-operated valve means to achieve conventional operation of the booster.
Should, for example, a wheel speed sensor emit a signal indicative of a `wheel-spin` condition then, in a normal inoperative position of the pedal, the controller operates the solenoid-operated valve means independently of the pedal to apply the brake on the spinning wheel.
The booster may be incorporated in an hydraulic braking system in which the pressure of fluid supplied to a wheel brake from a master cylinder operated by the booster is adapted to be modulated by a modulator in response to a signal from the electronic controller which, in turn, is initiated by a signal from the wheel speed sensor for the wheel operated by that brake. In such a system, should difficulty arise in controlling the solenoid-operated valve means sufficiently precisely for a smooth operation of the brake to be achieved for normal brake operation, then a given pressure generated by the master cylinder can be modified by the modulator in response to signals from the controller to achieve an appropriate brake-applying pressure.
In such a system the controller looks at pulses indicative of the approach of a critical rate of booster output and above which normal smooth operation of the brake is difficult to achieve, and the controller then actuates the modulator to control smoothly the subsequent rate of pressure increase applied to the brake.
In this mode of operation the master cylinder acts as a hydraulic accumulator having a range of progressively increasing stepped output pressures, and the modulator is adapted to determine the actual pressure which is applied to the brake by modifying the output from the accumulator, at least up to the maximum of a given step.
The booster can also be controlled in response to a wheel anti-lock signal to reduce the level of applied pressure, and to conserve the power source, particularly when vacuum is the medium.
In addition the booster can be operated to apply the brakes when the vehicle is on a collision course and the driver does not take the necessary action. In such a situation the controller receives a radar signal from a radar transmitter on the vehicle.
The booster may be adapted to modify its boost ratio to provide substantially the same vehicle deceleration for a given predetermined pedal effort irrespective of the vehicle's laden condition.
Finally the booster can be operated to apply the brakes in order to hold the vehicle on a hill or incline with the clutch pedal depressed. The controller automatically operates the solenoid-operated valve means to apply the brakes.
Preferably the solenoid-operated valve means comprises first and second independently operable solenoid-operated valves which can be operated by the controller in any desired sequence in accordance with at least one parameter obtaining at any given time, for example a pedal-generated electrical signal, a wheel spin signal, a wheel anti-lock signal, a remote radar signal, or a signal from a `hill-holder`.
BRIEF DESCRIPTION OF THE DRAWINGS
Some embodiments of our invention are illustrated in the accompanying drawings in which:
FIG. 1 is a layout of a hydraulic braking system for a vehicle including a vacuum-suspended booster;
FIG. 2 is a layout similar to FIG. 1 but including a hydraulic booster;
FIG. 3 is a layout of another hydraulic braking system in which a vacuum-suspended booster is remote from a pedal-operated hydraulic master cylinder;
FIG. 4 is a layout similar to FIG. 1 but showing a modified booster;
FIG. 5 is a layout similar to FIG. 2 but showing a modified booster;
FIG. 6 is a graph showing modulator control of booster output for a given critical rate; and
FIG. 7 is a graph similar to FIG. 6 but with different booster output characteristics and a different critical rate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the hydraulic braking system illustrated in FIG. 1 of the accompanying drawings a tandem hydraulic master cylinder 1 is adapted to be operated by a vacuum-suspended booster 2 in order to apply brakes 3,4 on front wheels 5,6 of a vehicle and brakes 7,8 on rear wheels 9,10 of the vehicle. Specifically the front wheel brake 3 and the diagonally opposite rear wheel brake 8 are applied from a primary pressure space of the master cylinder 1 through an anti-lock modulator assembly 10, and the front wheel brake 4 and the brake 7 on the diagonally opposite rear wheel are applied from the secondary pressure space through the modulator assembly 10. The modulator assembly comprises a separate modulator 3',4',7' and 8' for each respective brake 3,4,7 and 8.
The speed of each wheel is sensed by a respective speed sensor 11,12,13 and 14 from which signals are sent to an electronic controller in the form of a control modulator 15.
An hydraulic brake re-application pump associated with the modulator assembly 10 is driven by an electric motor 16 in response to an electric current emitted by the control module 15.
The vacuum-suspended booster 2 comprises a hollow housing 20 which is integral at its forward end with the master cylinder 1. The housing 20 has opposed end walls 21 and 22 at opposite ends of a cylindrical body wall 23. A piston 24 of stepped outline has a portion 25 of larger diameter and a portion 27 of smaller diameter. The portion 25 is connected at its outer edge to the body wall 23 by means of a rolling diaphragm 26 with which it defines a movable wall, and the portion 27 defines a hollow extension which extends rearwardly and projects outwardly through an opening 28 in the end wall 22. The extension 27 has a sliding sealing engagement in a seal 29 housed in a radial groove 30 in a wall defining the opening 28.
A constant pressure chamber 31 in the housing 20 between the piston 24 and the end wall 21 is normally subjected to a source of vacuum, suitable the inlet manifold of the vehicle, through a connection 49 passing through the wall 21. A servo or energizing pressure chamber 32 in the housing 20 between the piston 24 and the end wall 22 can be connected to the chamber 31, and can be isolated from the chamber 31 and/or connected to atmosphere through solenoid-operated valve means 33.
As illustrated the solenoid-operated valve means 33 comprises a first solenoid-operated inlet valve (A), and a second solenoid-operated isolating valve (B). The valve (A) has a valve head 34 for engagement with a seating 35 to close an inlet passage 36 from atmosphere, and the valve (B) has a valve head 37 which is normally spaced from a seating 38. In this open position the chambers 31 and 32 are in open communication through an external pipe 40 and a passage 41 which leads to the chambers 31 from the seating 38. The two valves (A) and (B) are in permanent communication through a passage 39.
Operation of the booster is initiated by a pedal which acts on a piston 42 working in a bore 43 in the extension 22 through a force input member in the form of a rod 44 to advance the piston 42 against the load in a spring 45. This movement is transmitted through a lever 46 to a dual electric switch 47 which sends signals to the control module 15, and through a reducing mechanism in the form of a block 48 of resilient material 8 to an output member in the form of a rod 50 which, in turn, acts on a primary piston 51 of the master cylinder 1. The reaction block 48 is housed in a recess 52 in the piston 25 with the piston 42 acting substantially on a central portion of the block 48.
In an inoperative position of the system the valve (A) is closed, the valve (B) is open, no signals are sensed for transmission to the control module 15, and the piston 24 is held in a retracted position by the force in a compression return spring 54, with both chambers 31 and 32 being subjected to equal negative pressures through the external connection 40.
When the brake pedal is actuated, the input rod 44 and the lever 46 move to operate the dual switch 47 which sends signals to the control module 15 to close the valve (B) and isolate the chamber 31 from the servo chamber 32, and to open the valve (A) to admit atmosphere into the servo chamber 32. In consequence, the piston 24 moves to actuate the master cylinder 12 through the output rod 50, and hydraulic pressure is applied to the brakes 3,4,7 and 8. The input and output forces are sensed and compared with an electronic comparator, the reducing mechanism 48, and the switch 47. Thus, when this pressure, acting over the master cylinder area, produces a force on the output rod 50 which is in a correct proportion to the input force, the valve (A) closes. For example, if the booster is to have a nominal boost ratio of 4:1, the output force will be four times the input force before the valve (A) closes.
Should the driver's input force be reduced, the control module 15 ensures the closure of the valve (A) before the valve (B) is opened to reduce the servo assistance pressure until the output rod force is in the correct proportion to the reduced input force. When this ratio is correct, the valve (B) closes again.
The booster 2, therefore, normally behaves in a similar manner to a conventional mechanically-operated booster but with the valves operated by solenoids from signals from an electronic control module.
The advantage of the construction of the booster 2 is that the valves (A) and (B) can be operated independently of the pedal in response to signals from the electronic control module 15.
TRACTION CONTROL
In the event of a driven wheel, say the wheel 5, spinning, which prevents traction from being applied to the other driven, non-spinning, wheel 6 of that pair, such a condition is sensed by the sensor 11 and is recognised by the control module 15. In response to such a signal, the control module 15 is operative to close the valve (B) and open the valve (A) so that the piston 24 applies a force to the master cylinder 1 which enables the brake 3 to be applied. At the same time, the anti-lock modulators 7' and 8' isolate the non-driven wheels 9 and 10 from the master cylinder, and the modulator 4' either isolates the brake 4 from the master cylinder 1, or controls the pressure level in the brake 4 in the event of the wheel 6 tending to spin after the wheel 5 has been corrected.
AUTOMATIC CONTROL
When the driven vehicle is equipped with radar to sense the proximity of another vehicle which may cause a collision, the booster 2 can be used progressively to apply the brake pressure automatically to retard the vehicle at the correct level commensurate with the comparative speeds of the two vehicles and the distance between them.
In such a case, the control module 15, in response to signals from the radar (R), closes the valve (B) and cycles the valve (A) until the vehicle deceleration is sufficient to prevent an accident. If the offending vehicle moves away, the valve (A) is closed and the valve (B) is cycled, or opened, to reduce, or release, the brake pressure. Of course, if the driver applies the brakes in the normal way, the automatic system will not be evoked.
HOLDING ON A HILL
When the vehicle comes to a halt upon an upward sloping hill and the clutch is depressed, the control module 15, in response to signals from the hill holder (H), will automatically apply the brakes by closing the valve (B) and opening the valve (A). The driver can now take his right foot off the brake pedal and move it to the accelerator in readiness to pull away. To move off, the driver presses upon the accelerator and eases in the clutch to engage engine drive. In doing so, the control module 15 releases the brakes by closing the valve (A) and opening the valve (B).
If sufficient braking force can be provided from one set of axle brakes, i.e. front or rear, the anti-lock modulator 10 will isolate that one set of brakes.
AUTOMATIC LIMITING OF SERVO ASSISTANCE
When the brakes are applied on a slippery surface, the level of brake pressure is automatically controlled by the modulator assembly 10 in response to signals from the control module 15, irrespective of how hard the driver is pressing upon the brake pedal. For example, if the driver, with assistance of the booster 2, generates a pressure of 100 bar within the master cylinder 1 but the brake pressure is controlled to 20 bar by the anti-lock modulator assembly 10, then the driver and the booster 2 are generating far too much pressure for the road surface conditions and the servo chamber 32 is fully pressurised with atmosphere. Furthermore the pump and motor 16 may be under undue strain. This occurs particularly in systems in which a pump is adapted to pump fluid back to a master cylinder 1.
To overcome this adverse situation, the control module 15 will put the booster into a `hold` position which both valves (A) and (B) are closed whenever all four wheels are being controlled by the anti-lock modulator assembly 10. Thus for the example above and assuming a 4:1 servo boost ratio, the master cylinder pressure will be ##EQU1## even though the driver is pressing with sufficient force on the brake pedal to generate 100 bar under normal conditions. This means that not only is the pressure opposing the pump reduced from 100 to 40 bar but also the servo chamber 32 is not fully pressurised. Vacuum energy is therefore conserved.
If the vehicle passes onto a surface of higher friction, the valve (A) opens to increase the servo boost and the applied pressure. Should the vehicle pass from high to low friction, no correction is made to the boost pressure because the energy to provide servo assistance has already been spent.
The servo assistance limiting feature will also give benefits during the re-application of pressure in an anti-lock mode. When pressure is re-admitted to the brakes 3,4,7, and 8 from the master cylinder 1, it is much easier to control a 40 bar input pressure for a 20 bar brake pressure than from a 100 bar pressure source. For higher skid pressures on better surfaces, a 60 bar average brake pressure will produce a master cylinder pressure of 70 bar, with servo assistance limited, instead of the 100 bar which can be applied conventionally.
The magnitude of servo assistance may also be limited as soon as the vehicle deceleration calculated from information supplied by wheel speed sensors 3,4,7 and 8 reaches a maximum. This will prevent over-pressurisation of the braking system of the vehicle. For the case of a laden vehicle, or for brake linings with low friction values, the level of assistance will increase proportionally. Means (L) to sense the laden condition of the vehicle sends signals to the control module 15, the control module 15 determining the level of level servo assistance required.
The operational functions of the booster 2 are illustrated in the following Truth Table I:
TABLE I______________________________________VALVE A B______________________________________NORMAL X OHOLD X XINCREASE O XDECREASE X OTRACTION O X______________________________________ O = Valve Open X = Valve Closed
In the braking system illustrated in the layout of FIG. 2 the vacuum-suspended booster 2 is replaced by an hydraulic booster 60.
As illustrated the booster 60 comprises a differential piston 61 having portions 62 and 63 of greater and smaller areas which work in corresponding portions of a stepped bore 64 in a housing 65 which is integral with the master cylinder 1. The portion of the bore which is of greater area is adjacent to the master cylinder 1.
A boost chamber 66 is defined in the bore 64 between a shoulder 67 on the piston 61 at the step in diameter, and a shoulder 68 at the step in diameter in the bore 64.
The free end of the piston portion 63 which projects from the housing 65 has a radial flange 69 which forms a mounting for an electric switch 70 from which signals are sent to the control module 15.
The solenoid-operated inlet valve (A) controls the admission into the boost chamber 66 of hydraulic fluid under pressure from an hydraulic accumulator (not shown), and the solenoid-operated valve (B) controls communication between the boost chamber 66 and a tank (not shown) for fluid.
Operation of the booster 60 is initiated by a pedal which acts on a piston 71 working in a bore 72 in the piston portion 63 through an input rod 73 to advance the piston 71 in the bore 72 against the load in a return spring 75. This causes a contact plate 74 at the outer end of the piston 71 to operate the switch 70. This movement of the piston 71 is also transmitted through a reducing mechanism in the form of a block 76 of resilient material to an output rod 77 which actuates the master cylinder 1.
In an inoperative position of the system the valve (A) is closed and the valve (B) is open so that the boost chamber 66 is unpressurised. The plate 74 is spaced from the switch 70 so that no signals are transmitted to the control module 15.
When the brake pedal is actuated, the input rod 73 moves to operate the switch 70. This sends signals to the control module 15 to close the valve (B) in order to isolate the boost chamber 66 from the tank and open the valve (A) to admit fluid under pressure into the boost chamber 66 from the accumulator. The boost piston 61 is then advanced in the bore 64 to operate the master cylinder 1 and apply the brakes on front and rear wheels of the vehicle in a similar manner to that of FIG. 1.
As in the construction of FIG. 1, the booster 60 responds to the actuation of a switch 70 which is operated by movement of the input rod 73, and uses a reaction block 76 to provide the driver with feedback at the pedal of the output force.
Since the construction and operation of the system of FIG. 2 is otherwise the same as that of FIG. 1 it will not be described further herein. Of course it is to be understood that the booster 60 is operable in response to signals from the control module 15 to perform all the functions described above with reference to FIG. 1, and as illustrated in the truth table I, as dictated by signals received by the control module 15 from wheel speed sensors, indicative of a wheel spin or an anti-lock condition, to achieve automatic control by radar, or to act as a hill holder.
In the layout illustrated in FIG. 3 of the accompanying drawings, a vacuum-suspended booster 80, similar in construction to the booster 2 of FIG. 1 is operated in conjunction with an hydraulic booster 81, similar in construction to the booster 60 of FIG. 2. The two boosters 80 and 81 constitute a single assembly.
As illustrated the solenoid-operated valves (A) and (B) are omitted from the booster 81, and the boost chamber 66 is connection with the booster 80 through an external connection.
The input rod 44, the piston 42, the lever 46, the switch 47, the reaction block 48, and the output rod 50 are replaced by a single output member 83 which is coupled to the piston 24 and extends through a seal 84 in the end wail 21 of the housing 20.
An auxiliary master cylinder 85 comprises a is housing 86 which is integral with the wall 21 and provided with a longitudinally extending bore 87. A piston 88 working in the bore 87 is adapted to be advanced in the bore 87 to pressurise fluid in a pressure space 89 in advance of the piston 88 and after initial movement of the piston 88 has caused the closure of a normally-open recuperation valve 90, whereby to isolate the space 89 from a reservoir for fluid through a reservoir connection 91. The pressure space 89 is connected to the boost chamber 66 through the external connection 82.
As before, the valves (A) and (B) are operated by the control module 15 to control operation of the booster 80 which, in turn, acts to pressurise the boost chamber 66 of the hydraulic booster 81.
In an inoperative position of the system the valve (A) is closed, the valve (B) is open, and the pistons 24 and 88 are in retracted positions with the recuperation valve 90 open.
When the brake pedal is actuated, the input rod 73 moves to operate the switch 70 which sends signals to the control module 15 to close the valve (B) and open the valve (A). The booster 80 then operates as described above with reference to FIG. 1 but with the piston 88 being advanced in the bore 87, initially to cause the recuperation valise 90 to close and thereafter to pressurise fluid in the pressure space 89, which fluid is transmitted through the connection 82, in turn to pressurise the boost chamber 66. The piston 62 acts to operate the master cylinder 1 in response to pressurisation of the boost chamber 66.
When the applied force and the servo forces balance the output force applied to the master cylinder 1, the valves (A) and (B) close to hold the pressure at that level.
The construction and operation of the system illustrated in the layout of FIG. 3 is otherwise the same as that of FIGS. 1 and 2, and corresponding references have been applied to corresponding parts.
The two boosters 80 and 81 are operable in conjunction with each other in response to signals from the control module 15 to perform all the functions described above with reference to FIGS. 1 and 2 and as illustrated in Truth Table I.
Since the two boosters 80 and 81 are remote from each other, the layout of FIG. 3 is particularly suited to vehicles where difficulty would otherwise be experienced in installing a booster/master cylinder assembly at a bulkhead.
In the braking system illustrated in the layout of FIG. 4 the booster is similar in construction to the booster 20 of FIG. 1. In this construction, however, the lever 46 and the dual valve 47 are omitted and the input piston 42 and the output rod 50 are each fitted with a respective load cell 95 and 96. The control module 15 is adapted to perform the task of comparing the two signals from the load cells 95 and 96 to determine the boost ratio.
This construction has a main advantage that we are able to modify the boost ratio to suit the various inputs. For example, an input signal of 200N may give a vehicle deceleration of 0.5 g for both `driver only` and `fully laden` conditions by changing to a higher boost ratio in the laden case.
The construction, operation and the functions of the system of FIG. 4 are otherwise the same as these of FIG. 1 and corresponding reference numerals have been applied to corresponding parts.
When a solenoid-operated valve (A) or (B) switches between an open position and a closed position, large quantities of fluid pressure pass through the respective valve at any one time with the result that the booster may be "over-energized". Should this occur there may be a tendency for the booster to overshoot and then "hunt" whilst trying to correct itself.
In the constructions described above, and particularly in the system illustrated in FIG. 4 of the drawings which embodies the load cells 95 and 96, the input load and the output load are measured when the output reaches substantially 75% of the input multiplied by the boost ratio. The solenoid of the inlet valve (A) is pulsed to reduce the rate of pressure rise within that cycle. This is arranged to occur for every switching, both for brake application and for brake release.
In the braking system illustrated in FIG. 5 of the accompanying drawings the booster is similar to the booster 60 of FIG. 2 except that the piston 71 works in a blind bore 100 in the piston 61. The block 76 is omitted so that the output rod 77 co-operates with a face 101 at the inner end of a blind bore 102 co-axial with the bore 100. The radial flange 69, the switch 70, and the contact plate 74 are omitted.
In a similar manner to that of the booster of FIG. 4 the input piston 71 is provided with an input load cell 110, and the output rod 77 is provided with an output load cell 111. Again the signals from the two load cells 110 and 111 are compared by the control module to determine the boost ratio.
The construction and operation of the system of FIG. 5 is otherwise the same as that of FIG. 2 and corresponding reference numerals have been applied to corresponding parts.
In the braking systems described above difficulty may arise in controlling the first inlet valve (A) with sufficient precision for a smooth braking operation to be achieved for normal braking. For example, when considering the booster 2 of FIG. 4 of which the operation is controlled by the load cells 95 and 96, under varying high rates of pressure demand the response time may not be sufficiently rapid to control this rate of pressure increase accurately without the generation of noticeably large stepped increases in the output force from the booster. This, in turn, would cause an equivalent pattern of output pressure from the master cylinder with the result that the pressure applied to the brakes would increase in steps and an unacceptable jerky brake pressure application would result.
To avoid this situation, which occurs when the rate of demand reaches a critical level at which the booster performance is unacceptable as described above, the booster 2 is actuated to produce the large stepped increases expected at a high rate of demand, and the modulators 3',4', 7' and 8' are operated to achieve a smooth pressure increase at the respective brakes. When the operation of each modulator is controlled by a solenoid-operated valve, the solenoid-operated valves are pulsed by the control module 15 to achieve the desired pressure control.
The modulator pulse rate may be controlled in any convenient manner.
In one example illustrated in FIG. 6, in which pressure (P) is plotted against time (t), when a given, relatively high, rate of pressure demand is sensed by the control module 15 from signals emitted by the load cells 95 and 96, the booster 2 is actuated by the valves (A) and (B), and is then held by the control module 15 in an appropriate mode so that the master cylinder 1 produces a maximum pressure output for a given step. In such a mode the assembly constituted by the booster 2 and the master cylinder 1 acts as an accumulator, and the solenoid-operated valves of the modulators 3', 4', 7' and 8' are pulsed by the control module 15 at a predetermined rate so as to produce a known pressure increase in the brakes above the critical rate at which the booster performance is unacceptable. This pulse rate is pre-calculated and determined by experimentation.
In another example, illustrated in FIG. 7, when the booster performance is unacceptable at a relatively low demand pressure and the modulators 2', 3' 7' and 8' are required to intervene and control the application of the brakes over a relatively wide range of demand pressures then, above the critical rate at which the booster performance is unacceptable, the pulse rate of the solenoid-operated valves of the modulators 2',3', 7' and 8' is varied in direct proportion to the rate of increasing demand as sensed by either the input load cell 95 or, alternatively, by a potentimeter or displacement transducer (not shown), conveniently attached to the brake pedal. In another arrangement the control module 15 itself senses that the critical rate is being approached with reference to the signals received from the wheel sensors 11, 12, 13, 14 when utilised in the traction control mode or the automatic control mode for collision avoidance.
The control module 15 is therefore adapted to control operation of the master cylinder 1 in steps above the critical rate so that the master cylinder 1 acts as an hydraulic accumulator of which the output pressure to the brakes is modulated by the respective modulator 2',3', 7' and 8' to smooth out the steps which otherwise, would have been applied to the brakes.
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Energization of a fluid-pressure operated booster is controlled solely by operation of a solenoid-operated valve device, suitably first and second solenoid-operated valves, responsive to signals from an electronic controller. The construction of the booster is therefore modified in comparison with known boosters by the omission of the conventional mechanical valve adapted to be operated by the pedal for normal operation of the booster.
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BACKGROUND OF THE INVENTION
The present invention relates to an image forming method and a printer, copier, facsimile apparatus or similar image forming apparatus using the same. More particularly, the present invention relates to an image forming apparatus of the type developing a latent image formed on a photoconductive drum or similar image carrier with toner or similar developer stored in a developing unit and transferring the resulting toner image to a paper sheet or similar recording medium.
An image forming apparatus of the type described is operable with a magnetic or nonmagnetic single ingredient type developer for developing a latent image electrostatically formed on an image carrier. A developing system using this type of developer includes a developer carrier contacting the image carrier while carrying the developer thereon in the form of a thin layer. The developer carrier is implemented as an elastic developing roller. With such a developing system, it is possible to obviate the scattering of the developer and thereby enhance the reproducibility of dots by, e.g., increasing a contact pressure between the image carrier and the developer carrier and a linear velocity ratio of the developer carrier to the image carrier.
However, the above developing system is susceptible to the fine oscillation of the image carrier and developer carrier. For example, when the contact pressure is increased, a drive source for setting the contact pressure must bear a heavy load. This is likely to bring about defective images ascribable to banding caused by irregular rotation.
To prevent the load on the drive source from increasing, the contact pressure of the developer carrier acting on the image carrier may be reduced, as proposed in the past. This conventional scheme, however, has a problem that the contact pressure is lower at the axially intermediate portion of the developer carrier than at the axially opposite end portions, causing the intermediate portion of an image to be lost. In light of this, Japanese Patent Laid-Open Publication No. 10-20857, for example, teaches a developer carrier having an intermediate portion greater in diameter than opposite and portions.
The developer carrier is generally formed of rubber. However, it is difficult to achieve dimensional accuracy with rubber, as distinguished from metal. This is particularly true when rubber has low hardness. In this condition, should the contact pressure between the image carrier and the developer carrier be lowered to reduce the load on the drive source, contact between them would easily become non-uniform and render irregularities conspicuous in an image. It is therefore necessary to strictly control the dimensional accuracy of the developer carrier. The dimensional accuracy involves various parameters, e.g., a tolerance in outside diameter, oscillation and cylindricality. However, despite the control over such parameters, it is sometimes difficult to reduce irregular images due to conditions in which the developer carrier is mounted. In addition, strict control over the dimensional accuracy increases cost.
The developer layer, or toner layer, deposited on the developer carrier contacts the surface of the image carrier. In this condition, an electrostatic force exerted by a latent image formed on the image carrier attracts toner existing in the toner layer and causes it to deposit on the latent image. In practice, however, a non-electrostatic force derived from e.g., the contact condition between the toner layer and the image carrier often causes the toner to deposit on the image carrier, particularly the background thereof where the electrostatic force of the latent image does not act on the toner. This contaminates the background to a noticeable degree.
Japanese Patent Laid-Open Publication No. 8-254933, for example, discloses an arrangement for obviating the background contamination of the image carrier. The arrangement is such that toner density outside the image area of the image carrier is sensed to determine the degree of background contamination. A device for applying a lubricant is held in contact with the image carrier. The amount of the lubricant to be applied to the image carrier is controlled in terms of a contact pressure in accordance with the degree of background contamination, thereby enhancing a cleaning effect.
Japanese Patent Publication No. 7-117788, for example, proposes a developing device operable with a nonmagnetic single ingredient type developer. In the developing device taught in this document, the amount of developer to deposit on the developer carrier is selected to be 0.6 mg/cm 2 to 1.2 mg/cm 2 . In addition, the ratio of the moving speed V 1 of the developer carrier to the moving speed V 2 of the image carrier is confined in the range of 0.6≦V 1 /V 2 ≦0.9. Those specific conditions are used to mechanically remove developer particles adhering to each other with a weak force without increasing the drive force.
The above lubricant scheme and linear speed ratio scheme, however, have a drawback that because the image carrier and developer carrier contact each other via the toner layer, the toner is apt to deposit on the image carrier due not only to the electrostatic force but also to the non-electrostatic force. This aggravates the background contamination of the image carrier.
To solve the above problem, it is a common practice to increase the contact pressure and linear velocity ratio at the time when image forming process conditions are set. The contact pressure, however, causes the previously stated banding to occur when increased. Also, the linear speed ratio of the developer carrier to the image carrier is apt to cause the toner to concentrate at the trailing edge of an image when increased.
On the other hand, the toner deposits on the developer carrier in a plurality of layers each having a particular amount of charge. Part of the toner existing in upper layers and short of charge are scattered onto the image carrier, contaminating the background of the image carrier. Further, as the toner coheres due to aging, an adhering force acting between toner particles increases and makes it difficult for them to migrate toward the image carrier when a halftone image, for example, is to be formed. This prevents a halftone image from being faithfully reproduced. Moreover, a defective image ascribable to banding becomes more conspicuous as the toner layer becomes thicker. Specifically, although a regulating member causes the toner to form a thin layer, any change in the contact pressure of the regulating member ascribable to irregular rotation makes the toner layer thickness irregular. Consequently, among toner particles existing on the developer carrier, the particles in upper layers not firmly deposited despite the electrostatic and non-electrostatic forces are susceptible to a change in thickness, causing the thickness of the toner layer to vary.
Japanese Patent Laid-Open Publication No. 9-197713, for example, teaches a method for obviating the fall of image density and tonality, paying attention to the fact that the cohesion of toner, among others, effects the reproducibility of a halftone image, as stated above. The method consists in specifying the variation of a degree of cohesion, an angle of repose and a loose apparent specific gravity due to aging as well as the configuration of toner particles. Also, Japanese Patent Laid-Open Publication No. 9-73229 proposes to specify the bulk density of the thin toner layer and the amount of toner to deposit on the image carrier for preventing an image from being blurred.
However, the above Laid-Open Publication No. 9-197713 contemplates to prevent image density from falling and therefore assumes a condition wherein the maximum amount of toner to deposits. The above Laid-Open Publication No. 9-73229 contemplates to increase image density by preventing the toner from depositing on a non-image area and, for this purpose, makes the thickness of the thin toner layer uniform. None of such schemes is therefore directed toward a halftone image. More specifically, the image carrier and developer carrier sandwich the toner at a nip for development and cause it to easily cohere. Cohesion increases the packing density of the toner and therefore the adhering force acting between the toner particles, degrading the reproducibility of a halftone image.
Technologies relating to the present invention are also disclosed in, e.g., Japanese Patent Laid-Open Publication Nos. 4-372981, 6-258933, 6-295130, 8-305075, 9-179389, 10-69162, 11-84878 and 11-149174 as wall as in Japanese Patent No. 2,715,337.
SUMMARY OF THE INVENTION
It is therefore a first object of the present invention to provide an image forming apparatus capable of reducing irregular images without increasing cost by including a developer carrier contacting an image carrier and provided with dimensional accuracy based on new criteria.
It is another object of the present invention to provide an image forming apparatus of the type including a developer carrier for electrostatically retaining a developer thereon and a regulating member for causing the developer to form a thin layer, and capable of protecting the image carrier from background contamination and insuring faithful reproduction of a halftone image.
In accordance with the present invention, in an image forming method for electrostatically forming a latent image on the uniformly charged surface of an image carrier by optical writing, causing a developer carrier on which a single ingredient type developer is deposited to contact the image carrier to thereby develop it while controlling a contact pressure, transferring the developed image to a recording medium, and fixing the developed image on the recording medium, the developer carrier is implemented as a cylindrical member. Assume that any two points on ridgelines are connected by a line in any section passing through the axis of the developer carrier, that the maximum distance between ridgelines present between the above line and the two points is T in the normal direction, and that the displacement of the developer carrier to occur when a contact pressure is applied to the developer carrier located at one side between the two points and contacting facing one of the ridgelines with no load is L. Then, there holds a relation:
T<L
Also, in accordance with the present invention, in an image forming apparatus for electrostatically forming a latent image on the surface of an image carrier having a coefficient of friction μ lying in a range of 0.1≦μ≦0.4 and uniformly charged beforehand by optical writing, causing a developer carrier on which a single ingredient type developer is deposited to contact the image carrier to thereby develop the latent image while controlling a contact pressure, transferring the developed image to a recording medium, and fixing the developed image on the recording medium, the volume mean particle size Tr (cm) of the developer, the amount M (mg/cm 2 ) of the developer to deposit on the developer carrier and the bulk density ρ (mg/cm 3 ) of the developer have a following relation when the developer is pressed by a pressure of 100 gf/cm 2 :
0.5 ρRt≦M≦ 1.2 ρRt
The developer should preferably have a loose apparent density of 0.35 or above. Also, the developer should probably have its configuration determined by sphericality and have sphericality of 90% or above with respect to true sphericality. Further, a plurality of particles should stay in the vicinity of the developer carrier.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken with the accompanying drawings in which:
FIG. 1 is a view showing essential part of a first embodiment of an image forming apparatus in accordance with the present invention;
FIG. 2A is a view showing a specific condition wherein a developing roller contacts a photoconductive drum with a load of 0 g/mm;
FIG. 2B is a view showing another specific condition wherein the developing roller is pressed against the photoconductive drum by a pressure F;
FIG. 3 is a view for describing a specific parameter relating to the illustrative embodiment;
FIG. 4 is a view showing a specific contact condition between an image carrier and a developer carrier achievable with the illustrative embodiment;
FIG. 5 is a view showing another specific contact condition between the image carrier and the developer carrier achievable with the illustrative embodiment;
FIG. 6 is a view showing part of the illustrative embodiment including the developer carrier;
FIG. 7 is a graph showing the characteristic of the developer carrier included in the illustrative embodiment;
FIG. 8 is a view showing essential part of a second embodiment of the present invention;
FIG. 9 is a view showing a specific experimental arrangement for determining a coefficient of friction on the surface of an image carrier included in the second embodiment;
FIG. 10 is a view showing toner particles forming layers between the image carrier and the developer carrier in a conventional configuration;
FIG. 11 is a view similar to FIG. 10, showing toner particles forming a substantially single layer in the illustrative embodiment;
FIG. 12 is a view showing essential part of the first and second embodiments;
FIG. 13 is a table representative of a relation between the contact pressure between the image carrier and the developer carrier and the background contamination and defective images;
FIG. 14 is a table showing a relation between the loose apparent density of toner and the reproducibility of a halftone image;
FIG. 15 is a view showing a relation between a cohering force to act between developer particles and a force causing them to migrate to a latent image;
FIG. 16 is a table showing a relation between the sphericality of toner particles and the reproducibility of a halftone image; and
FIG. 17 is a view showing a relation between the image carrier and regulating means included in the arrangement of FIG. 12 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described hereinafter. It is to be noted that because particular reference numerals are used in each embodiment, identical reference numerals do not always designate identical structural elements.
First Embodiment
Referring to FIG. 1 of the drawings, an image forming apparatus embodying the present invention is shown. The illustrative embodiment is directed mainly to the first object of the present invention stated earlier. As shown, the image forming apparatus includes a photoconductive element or image carrier implemented as a drum 1 and formed of an organic or inorganic photoconductor. A drive source, not shown, causes the drum 1 to rotate in a direction indicated by an arrow in FIG. 1. A charger 2 , an optical writing device (represented by an optical path) 3 , a developing unit 4 , an image transfer device 5 and a cleaning device 6 are sequentially arranged around the drum 1 in the direction of rotation of the drum 1 for implementing an image forming process. The charger 2 uniformly charges the surface of the drum 1 being rotated. The optical writing device 3 exposes the charged surface of the drum 1 imagewise to thereby form a latent image on the drum 1 .
The developing unit 4 develops the above latent image with a developer at a position P 1 to thereby produce a corresponding toner image. A paper sheet or similar recording medium S is fed from a paper feeder (represented by a registration roller pair 7 ) to a position P 2 where the drum 1 and image transfer device 5 face each other. The image transfer device 5 transfers the toner image from the drum 1 to the paper sheet S. After the image transfer, the cleaning device 6 scrapes off the developer left on the drum 1 . Subsequently, a discharger, not shown, discharges the surface of the drum 1 to thereby prepare it for the next image forming cycle. After a fixing device, not shown, has fixed the toner image on the paper sheet S, the paper sheet S is driven out of the apparatus to a tray not shown.
In the illustrative embodiment, the developer is implemented as a single ingredient type developer, i.e., toner. Toner provided in the form of particles consists of a mixture of polyester, polyol, styrene-acryl or similar resin, a charge control agent (CCA) and a coloring agent, and silica, titanium oxide or similar substance applied to the particles. The particles have a mean particle size of 3 μm to 12 μm, 7.5 μm in the illustrative embodiment. With such a mean particle size, it is possible to meet the demand for high resolution and to further reduce the particle size for even higher resolution.
The developing device 4 includes a developing roller or developer carrier 4 A for executing so-called contact development. The developing roller 4 A is held in contact with the drum 1 . A casing 4 B also included in the developing device 4 accommodates the developing roller 4 A, a feed roller 4 C facing the developing roller 4 A, an agitator 4 D adjoining the feed roller 4 C, and a metering blade or regulating member 4 E contacting the developing roller 4 A.
The developing roller is formed of rubber and provided with an outside diameter of 10 mm to 30 mm. For the rubber, use may be made of silicone rubber, butadiene rubber, nitrile-butadiene rubber (NBR), hydrine rubber or EPDM. The surface of the developing roller 4 A may be covered with a silicone- or Teflon-based coating material in order to stabilize quality against aging, if desired. A silicone-based coating material allows the toner to be efficiently charged while the Teflon-based material has a high parting ability. In addition, the coating layer on the developing roller 4 A may contain carbon black or similar conductive substance. The coating layer should preferably be 4 μm to 50 μm thick; thickness above this range is apt to cause the coating layer to crack. In the illustrative embodiment, the developing roller 4 A has lower hardness than the drum 1 . Alternatively, use may be made of a hard developing roller and a photoconductive element implemented as a soft belt.
The feed roller 4 C is formed of foam polyurethane or similar flexible material having a cell size of 50 μm to 500 μm, so that the toner can be easily held on the surface of the roller 4 C. The surface of the feed roller 4 C has relatively low hardness ranging from 10° to 30°, as measured by JIS (Japanese Industrial Standards) A scale, so as to evenly contact the developing roller 4 A. The surface of the feed roller 4 C bites into the developing roller 4 A by 0.5 mm to 1.5 mm. The feed roller 4 C is rotatable in the same direction as the developing roller 4 A such that the surface of the former moves in the opposite direction to the surface of the latter contacting it. The linear velocity ratio of the feed roller 4 C to the developing roller 4 A is selected to be between 0.5 and 1.5, 0.9 in the illustrative embodiment.
In the illustrative embodiment, the particular range of bite mentioned above implements torque ranging from 1.5 kg·fcm to 2.5 kg·fcm necessary for a unit effective width of 240 mm available with the developing unit 4 . This unit effective width corresponds to the width of a paper sheet of size A4 fed in a profile position, as distinguished from a landscape position. However, a broader range of bite may be selected because the amount of bite depends on the characteristics of a motor, gear head and so forth included in a driveline assigned to the developing unit 4 as well as on the charge and feed characteristics of the toner.
Charge is frictionally induced on the toner existing on or in the surface of the feed roller 4 C when brought to a nip between the feed roller 4 C and the developing roller 4 A. In the illustrative embodiment, negative charge is induced on the toner due to the characteristic of the toner. The toner charged to negative polarity is held on the surface of the developing roller 4 A due to a conveying effect derived from the surface roughness of the roller 4 A. The toner transferred from the feed roller 4 C to the developing roller 4 A is not uniform in thickness, but deposited to excessive thickness (1 mg/cm 2 to 3 mg/cm 2 ). The metering blade 4 E regulates such a toner layer to uniform thickness.
The developing roller 4 A rotates in a direction indicated by an arrow in FIG. 1 . The metering blade 4 E is affixed to the casing 4 B at one end thereof. The other end of the blade 4 E extends to the downstream side in the direction of rotation of the developing roller 4 A. In this condition, the blade 4 E contacts the circumference of the developing roller 4 A at its intermediate portion between the opposite ends in a so-called counter position. The blade 4 E is formed of metal, e.g., SUS 304 and 0.1 mm to 0.15 mm thick. The length of the blade 4 E between the position where the blade 4 E contacts the developing roller 4 A and the free end is selected to be 0.1 mm to 2.0 mm.
Alternatively, the metering blade 4 E may be formed of 1 mm to 2 mm thick resin having relatively high hardness, e.g., polyurethane rubber or similar rubber, silicone resin or fluorocarbon resin that inverts the charging characteristic (e.g. ETFE, PTFE or PVdF). Even materials other than metals can be lowered in resistance if, e.g., carbon black is mixed therewith. Such a metering blade 4 E can form an electric field between it and the developing roller 4 A with a bias applied from a bias power source.
The length of the metering blade 4 E between the contact point and the free end should preferably be 8 mm to 15 mm. Lengths greater than 15 mm would make the developing device 4 bulky. Lengths small or than 8 mm would cause the blade 4 E to oscillate on contacting the developing roller 4 A and would thereby cause irregularities to appear in an image in the horizontal direction or otherwise make an image defective.
The metering blade 4 E contacts the developing roller 4 A with a pressure ranging from 1 gf/cm to 25 gf/cm. In this condition, the blade 4 E crapes off non-charged toner particles deposited on the developing roller 4 A and regulates the toner layer to uniform thickness. Pressure higher than 25 gf/cm would reduce the amount of toner to deposit on the developing roller 4 A and increase the amount of toner charge excessively and would thereby lower image density due to short development. Pressure lower than 1 gf/cm would prevent the toner from forming a uniform thin layer and cause it to move away from the blade 4 E in the form of lumps, thereby degrading image quality to a critical degree.
In the illustrative embodiment, the developing roller 4 A is implemented by SUS having hardness of 40° (JIS A scale) and thickness of 0.1 mm. The contact pressure is selected to be 6 gf/cm. This allows the metering blade 4 E to scrape off excess toner deposited on the developing roller 4 A and form a thin toner layer having uniform thickness. The toner with an amount of charge of −5 μC/g to −30 μC/g is transferred from the developing roller 4 A to a latent image formed on the drum 1 .
The drum 1 and developing roller 4 A contact each other with the intermediary of the toner layer formed on the developing roller 4 A. A drive source, not shown, causes the developing roller 4 A to rotate. A relation between the drum 1 and the developing roller 4 A will be described specifically with reference to FIGS. 2A and 2B. FIG. 2A shows a specific condition wherein the developing roller 4 A contacts the drum 1 with a load of 0 g/mm. FIG. 2B shows another specific condition wherein the developing roller 4 A is pressed against the drum 1 by a pressure F. As shown, assume that the developing roller 4 A moves by a distance L when pressed against the drum 1 . Also, assume that any two points on ridgelines are connected by a line in any section passing through the axis of the developer carrier, and that the maximum distance between ridgelines present between the above line and two points is T in the normal direction. More specifically, the maximum distance T refers to the distance in the radial direction between the drum 1 and the developing roller 4 A as to the relative position. Then, a relation of T<L holds between the drum 1 and the developing roller 4 A.
More specifically, when the distance T is greater than the displacement L, a gap appears between the drum 1 and the developing roller A and brings about irregular density and local omission of an image. To avoid such a gap, it is necessary to provide the developing roller 4 A with a dimension capable of reducing the distance T and to cause the roller 4 A to bite into the drum 1 to such a degree that the gap disappears.
However, if the above gap is caused to disappear, a pressure used for such a purpose makes the contact pressure non-uniform in the axial direction and results in irregular images and the need for extra drive torque. For example, assuming that the displacement L is 0.05 mm, the developing roller 4 A may be provided with a tolerance of +0.05 in outside diameter in order to set up an adequate contact condition. FIG. 3 shows the resulting contour of the developing roller 4 A. As FIG. 3 indicates, even when the desired displacement L is guaranteed, a gap appears and makes images irregular. In this manner, the conventional configuration cannot implement a uniform image with the outside diameter of the developing roller 4 A and therefore must define the oscillation and cylindricality of the same as well.
In the illustrative embodiment, the maximum distance T in the radial direction is selected to be smaller than the displacement L, as stated above. The maximum distance T is therefore less than 0.05 mm and does not produce any gap. Specifically, as shown in FIGS. 4 and 5, the circumference of the developing roller 4 A contacts the drum 1 in parallel to the drum 1 , i.e., without any gap. That is, a gap does not appear between the developing roller 4 A and the drum 1 even if oscillation or cylindricality differs from a preselected value.
Particularly, as shown in FIG. 6, a support section supporting the developing roller 4 A includes a plurality of elastic members 50 . The elastic members 50 cause the circumference of the developing roller 4 A to extend in parallel to that of the drum 1 at a plurality of axial positions including opposite ends. More specifically, a bearing portion supporting the shaft of the developing roller 4 A is supported in such a manner as to be movable in the direction perpendicular to the circumference of the drum 1 . Therefore, the axially opposite ends of the bearing portion are movable in the above direction independently of each other. In this condition, when the developing roller 4 A is moved toward the drum 1 by the displacement L, the roller 4 A is automatically positioned such that the circumference thereof is parallel to the circumference of the drum 1 . The developing roller 4 A can therefore evenly contact the drum 1 in the axial direction without any strict control over oscillation or cylindricality. The elastic members 50 are formed of rubber or a spring material.
As stated above, the illustrative embodiment insures uniform contact of the developing roller 4 A and drum 1 simply by setting a particular relation between the distance between the circumference of the drum 1 and that of the developing roller 1 and the displacement of the roller 4 A relative to the drum 1 . This makes it needless to strictly control the outside diameter, oscillation or cylindricality of the developing roller 4 A.
How the developing roller 4 A contacts the drum 1 is dependent also on the hardness of the surface of the roller 4 A, as will be described hereinafter. If the contact pressure of the developing roller 4 A acting on the drum 1 is short, the roller 4 A fails to scrape off the toner left on the drum 1 after image transfer with expected efficiency. If the contact pressure is excessive, it increases the drive torque and brings about the omission of dots in a halftone image. In light of this, the illustrative embodiment presses the developing roller 4 A against the drum 1 with a pressure of 2 g/mm to 8 g/mm
More specifically, FIG. 7 shows are relation between the surface hardness of the developing roller 4 A and the amount of bite of the roller 4 A into the drum 1 whose diameter is 50 mm. As shown, when the distance T of 0.05 mm should be set up between the circumference of the drum 1 and that of the developing roller 4 A, the above contact pressure is achievable if the surface hardness of 40°. From the machining standpoint, it is difficult to reduce the distance T to less than 0.05 mm when it comes to an elastic member having low hardness. For this reason, the hardness of 40° achievable with the contact pressure of 7 g/mm when the amount of bite is 0.05 mm is selected as an upper limit. This is successful to prevent machining cost from increasing when gap accuracy lower than the above accuracy is selected.
In the above configuration, the developing roller 4 A is provided with hardness implementing a contact pressure corresponding to an amount of bite that corresponds to the displacement of the roller 4 A. As a result, machining cost is successfully prevented from increasing when a gap relating to the amount of bite is to be set.
On the other hand, so long as the developing roller 4 A has high hardness, it can be ground after molding in order to set up the distance T. However, the developing roller 4 A with low hardness cannot be easily ground and has, in many cases, dimensions determined by vulcanization molding. However, the outside diameter of the developing roller 4 A is apt to increase at its opposite end portions during molding due to a cooling rate and other conditions, resulting in the configuration shown in FIG. 3 .
To solve the above problem, in the illustrative embodiment, the opposite end portions of the developing roller 4 A are chamfered. This allows the outside diameter of the intermediate portion of the roller 4 A, i.e., the distance T between the roller 4 A and the drum 1 to be easily set. Further, seal members for preventing the toner from flying about are often pressed against the opposite end portions of the roller 4 A. In this respect, chamfering prevents the surface layer of the roller 4 A from sequentially coming off from the end portions due to friction. In the worst case, the surface layer would come off to the image forming area of the roller 4 A.
As stated above, the illustrative embodiment achieves various unprecedented advantages, as enumerated below.
(1) The maximum distance T is selected to be smaller than the displacement L, as stated earlier. Therefore, only if a displacement greater than the maximum distance is selected, the developer carrier can uniformly contact the image carrier by canceling the maximum distance. It follows that when the contact pressure is low, contact is guaranteed without resorting to strict control over the tolerance of the outside diameter, oscillation or cylindricality of the developer carrier. Specifically, even when the developer carrier is formed of rubber or similar elastic material that is lower in hardness than metal and difficult to grind, desirable contact is achievable without increasing machining cost and obviates irregular images.
(2) The developer carrier has a surface provided with a particular hardness. Therefore, even when the contact pressure of the developer carrier to act on the image carrier is low, uniform contact is achievable and obviates irregular images.
(3) When the developer carrier is formed of an elastic body higher in hardness than metal, axially opposite end portions of the developer carrier are chamfered in order to easily set up the relation stated in the above item (1). This is successful to easily obviate defective images without increasing machining cost.
(4) Even when the contact of the developer carrier with the image carrier is not uniform due to errors in the section on which the developer carrier is mounted, the circumference of the developer carrier can be parallel to the circumference of the image carrier. In addition, in the above mounting condition, the relation stated in the item (1) allows the developer carrier to uniformly contact the image carrier. Particularly, when other members contact the end portions of the developer carrier, they are prevented from peeling the surface layer of the developer carrier. This prevents the surface characteristic of the developer carrier and therefore the developer feed condition from varying.
Second Embodiment
FIG. 8 shows an alternative embodiment of the present invention that is directed toward the second object stated earlier. As shown, an image forming apparatus includes a photoconductive drum or image carrier 1 and a developing unit or developer feeding means 2 . Again, the developing unit 2 stores a single ingredient type developer or toner. The drum is formed of an organic or inorganic photoconductor and provided with a diameter of 50 mm and a coefficient of friction μ lying in the range of 0.1≦μ≦0.4, as measured on its surface.
FIG. 9 shows an Euler's belt type arrangement used to determine the above range of coefficient of friction μ. As shown, a paper sheet of size A4 (Type 6200 available from Ricoh Co., Ltd.) was cut in a size of 297×30 mm and had its intermediate portion passed over the drum 1 over an angle of 90° (π/2 rad.). A weight W having a preselected weight of 0.98 N (100 g) was attached to one end of the paper sheet S. A digital push-pull gauge DS was affixed to the other end of the paper sheet S. While the weight W was prevented from swinging, the paper sheet S was pulled at a preselected speed. When the paper sheet S started moving, the value of the gauge DS was read. Assuming that the measured value of the gauge DS is F(N), then the coefficient of friction μ is produced by:
μ=ln( F/ 0.98)/(π/2)
Among coefficients of friction μ determined with the above arrangement and procedure, coefficients lying in the following range were determined to prevent the toner from depositing on the drum 1 when the toner was rubbed into the drum 1 by a pressure exerted by the toner layer, and therefore to obviate background contamination.
While the coefficient of friction μ ranged from 0.4 to 0.6 when a lubricant or similar agent was not applied to the surface of the drum 1 , it tended to increase due to aging. By contrast, the drum 1 applied with a lubricant was found to have a coefficient of friction μ ranging from 0.1 to 0.4. Therefore, if the drum 1 is provided with a coefficient of friction between 0.1 and 0.4, the toner can be prevented from being rubbed into the drum 1 , particularly the background, due to friction.
When the toner has a volume mean particle size of 4 μm to 10 μm, the above range of coefficients of friction can be maintained if a substance capable of lowering the coefficient of friction of the drum 1 , i.e., a so-called lubricant is applied to the drum 1 . For this purpose, a lubricant may be directly applied to the drum 1 every time the image forming cycle is repeated a preselected number of times, or applying means loaded with a lubricant may contact the drum 1 either constantly or every time the copying cycle is repeated a preselected number of times. This kind of scheme is taught in. e.g., Japanese Patent Laid-Open Publication No. 4-372981 mentioned earlier.
The drum 1 is charged to a preselected surface potential by conventional charging means and then scanned by conventional optical writing means. As a result, a latent image is electrostatically formed on the drum 1 in accordance with image data.
As shown in FIG. 8, the developing device 2 includes a casing 2 A accommodating a developing roller 2 B facing the drum 1 , a feed roller 2 C facing the developing roller 2 B, a metering blade or regulating member 2 D for regulating the thickness of the toner deposited on the developing roller 2 B, and an agitator 2 E.
The toner provided in the form of particles consists of a mixture of polyester, polyol, styrene-acryl or similar resin, a charge control agent (CCA) and a coloring agent, and silica, titanium oxide or similar substance applied to the particles. The particles have a mean particle size of 3 μm to 12 μm. 7.5 μm in the illustrative embodiment. With such a mean particle size, it is possible to meet the demand for high resolution (1,200 dpi (dots per inch)) and to further reduce the particle size for even higher resolution.
The developing roller 2 B is formed of rubber and provided with an outside diameter of 10 mm to 30 mm. For the rubber, use may be made of silicone rubber, butadiene rubber, nitrile-butadiene rubber (NBR), hydrine rubber or EPDM. The surface of the developing roller 2 B may be covered with a silicone- or Teflon-based coating material in order to stabilize quality against aging, if desired. A silicone-based coating material allows the toner to be efficiently charged while the Teflon-based material has a high parting ability. In addition, the coating layer on the developing roller 2 B may contain carbon black or similar conductive substance. The coating layer should preferably be 5 μm to 50 μm thick; thickness above this range is apt to cause the coating layer to crack. In the illustrative embodiment, the developing roller 2 B has lower hardness than the drum 1 . Alternatively, use may be made of a hard developing roller and a photoconductive element implemented as a soft belt.
The feed roller 2 C is formed of foam polyurethane or similar flexible material having a cell size of 50 μm to 500 μm, so that the toner can be easily held on the surface of the roller 2 C. The surface of the feed roller 2 C has relatively low hardness ranging from 10° to 30° (JIS A scale) so as to evenly contact the developing roller 4 A. The surface of the feed roller 2 C bites into the developing roller 2 B by 0.5 mm to 1.5 mm. The feed roller 2 C is rotatable in the same direction as the developing roller 2 B such that the surface of the former moves in the opposite direction to the surface of the latter contacting it. The linear velocity ratio of the feed roller 2 C to the developing roller 2 B is selected to be between 0.5 and 1.5, 0.9 in the illustrative embodiment. When the feed roller 2 C is rotated in the opposite direction to the developing roller 2 B (in the same direction at the contact position), the linear velocity ratio should preferably be 0.8 to 1.5.
In the illustrative embodiment, the particular range of bite mentioned above implements torque ranging from 1.5 kg·fcm to 2.5 kg·fcm necessary for a unit effective width of 240 mm available with the developing unit 2 . This unit effective width corresponds to the width of a paper sheet of size A4 fed in a profile position, as distinguished from a landscape position. However, a broader range of bite may be selected because the amount of bite depends on the characteristics of a motor, gear head and so forth included in a driveline assigned to the developing unit 2 as well as on the charge and feed characteristics of the toner.
Charge is frictionally induced on the toner existing on or in the surface of the feed roller 2 C when brought to a nip between the feed roller 4 C and the developing roller 2 B. In the illustrative embodiment, negative charge is induced on the toner due to the characteristic of the toner. The toner charged to negative polarity is held on the surface of the developing roller 2 B due to a conveying effect derived from the surface roughness of the roller 2 B. The toner transferred from the feed roller 2 C to the developing roller 2 B is not uniform in thickness, but deposited to excessive thickness (1 mg/cm 2 to 3 mg/cm 2 ). The metering blade 2 D regulates such a toner layer to uniform thickness. If desired, the feed roller 2 C may be rotated in the opposite direction to the developing roller 2 B (in the same direction at the contact position).
The developing roller 2 B rotates in a direction indicated by an arrow in FIG. 8 . The metering blade 2 D is affixed to the casing 2 A at one end thereof. The other end of the blade 2 D extends to the downstream side in the direction of rotation of the developing roller 2 B. In this condition, the blade 2 D contacts the circumference of the developing roller 2 B at its intermediate portion between the opposite ends in a so-called counter position. The blade 2 D is formed of metal, e.g., SUS 304 and 0.1 mm to 0.15 mm thick.
It is to be noted that the metering blade 2 D may contact the developing roller 2 B in the opposite relation (trailing position) or at its free end.
If desired, the metering blade 2 D may be formed of 1 mm to 2 mm thick resin having relatively high hardness, e.g., polyurethane rubber or similar rubber, silicone resin or fluorocarbon resin that inverts the charging characteristic (e.g. ETFE, PTFE or PVdF). Even materials other than metals can be lowered in resistance if, e.g., carbon black is mixed therewith. Such a metering blade 2 D can form an electric field between it and the developing roller 28 with a bias applied from a bias power source.
The length of the metering blade 2 D between the contact point and the free end should preferably be 8 mm to 15 mm. Lengths greater than 15 mm would make the developing device 2 bulky. Lengths smaller than 8 mm would cause the blade 2 D to oscillate on contacting the developing roller 2 B and would thereby cause irregularities to appear on an image in the horizontal direction or otherwise make an image defective.
The metering blade 2 D contacts the developing roller 2 B with a pressure ranging from 1 gf/cm to 25 gf/cm. In this condition, the blade 2 D scrapes off non-charged toner particles deposited on the developing roller 2 B and regulates the toner layer to uniform thickness. Pressure higher than 25 gf/cm would reduce the amount of toner to deposit on the developing roller 2 B and increase the amount of toner charge excessively and would thereby lower image density due to short development. Pressure lower than 1 gf/cm would prevent the toner from forming a uniform thin layer and cause it to move away from the blade 2 D in the form of lumps, thereby degrading image quality to a critical degree.
In the illustrative embodiment, the developing roller 2 B is implemented by SUS having hardness of 40° (JIS A scale) and thickness of 0.1 mm. The contact pressure is selected to be 6 gf/cm. This allows the metering blade 2 D to scrape off excess toner deposited on the developing roller 2 B and form a thin toner layer having uniform thickness. The toner with an amount of charge of −5 μC/g to −30 μC/g is transferred from the developing roller 2 D to a latent image formed on the drum 1 .
The behavior of the toner in the developing region will be described hereinafter. FIGS. 10 and 11 respectively show the deposition of toner to occur in a conventional structure and in the illustrative embodiment. As shown in FIG. 10, in the conventional structure, tone particles deposit in a plurality of layers while the amount of charge sequentially decreases from the bottom layer toward the top layer. Specifically, there holds a relation of a>b>c where a, b and c are representative of consecutive layers. For example, when the toner is charged to −17 μC/g to −20 μC/g, the bottom layer and top layer respectively have an amount of charge of −20 μC/g to −25 μC/g and an amount of charge of −12 μC/g to −17 μC/g. This is because toner particles not sufficiently charged move away from the metering blade 2 D due to a short regulating force.
Assume that the drum 1 has the coefficient of friction of 0.4 or below, as stated earlier. Then, an adhering force between the drum 1 and the toner particles tends to decrease. As a result, toner particles in upper layers that are short of charge, compared to toner particles in lower layers, are apt to fly about on the drum 1 and contaminate the background of the drum 1 . Further, assume that the degree of cohesion of toner particles and therefore the adhering force acting between the particles increases, as stated earlier. Then, when a halftone image, for example, is developed by using part of the toner deposited on the developing roller 2 B, some toner particles are not transferred to the drum 1 , preventing a halftone image from being faithfully reproduced.
Another problem with toner particles deposited in multiple layers is that banding occurs in an image due to the irregular rotation of the developing roller 2 B. Specifically, when the coefficient of friction of the drum 1 is less than 0.1, any irregularity in the rotation of the developing roller 2 B reduces the adhering force to a noticeable degree and prevents some toner particles from being transferred to the drum 1 .
Banding also occurs when the contact pressure of the metering blade 2 D is not uniform due to the irregular rotation of the developing roller 2 B. Specifically, in FIG. 10, toner particles in the layers other than the layer a are short of charge and do not contact the developing roller 21 B. Therefore, the adhering force between such toner particles and the developing roller 2 B is extremely weak and causes the metering blade 2 D to easily scrape off the toner particles, varying the thickness of the entire toner. Consequently, the amount of development is not constant and brings about banding.
In light of the above, as shown in FIG. 11, the illustrative embodiment forms a substantially single toner layer by causing the toner to deposit on the developing roller 2 B in an amount M (mg/cm 2 ) lying in the following range:
0.5 ρRt≦M≦ 2 ρRt
where Rt denotes the volume mean particle size (cm) of the toner, and ρ denotes a bulk density (mg/cm 3 ).
The above relation is achievable by increasing the contact pressure of the metering blade 2 D and reducing the length of the part of the blade 2 D extending from the developing roller 2 B. The single toner layer has a uniform amount of charge and therefore does not bring about background contamination ascribable to short charge. For example, assume that the toner has volume mean particle size (cm) of 7.5 (μm), and specific gravity of 1.2. Then, when the toner is pressed by 100 gf/cm 2 , the bulk density is 0.6. The lower limit of the amount M is therefore 1.2 aRt=0.27 mg/cm 2 ; amounts M below the lower limit would fail to implement a sufficient amount of development. The upper limit of the amount M is 1.2aRt=0.65 mg/cm 2 ; amounts M above the upper limit would cause an excessive amount of toner to deposit in multiple layers, as stated earlier.
With the above particular relation, the illustrative embodiment prevents the adhering force between toner particles ascribable to cohesion from increasing due to aging. Further, the distance between the drum 1 and the developing roller 2 B (labeled h 2 in FIG. 11) is far shorter than in the condition shown in FIG. 10, allowing toner particles to easily and faithfully migrate toward a latent image formed on the drum 1 .
As for banding, the metering blade 2 D does not scrape off the upper toner layers even though its pressure may vary. More specifically, because the toner firmly deposits on the developing roller 2 B on the basis of a mirror image force and van der Waals' forces, the toner is scraped off little despite the variation of the contact pressure and therefore changes its thickness little. This successfully reduces banding. To set the desired amount of development on the drum 1 , the linear velocity ratio of the developing roller 2 B to the drum 1 should preferably be 1.5 to 2.0.
In the illustrative embodiment, the nip between the drum 1 and the developing roller 2 B has a width W lying in the range of 0.3≦W≦3.0. Nip widths greater than 3.0 lower the uniformity of the toner and make a solid image irregular because a scavenging effect that causes the developing roller 2 B to scrape off the toner from the drum 1 increases. This depends on the hardness and contact condition of the developing roller 2 B.
To implement desired image density and to avoid background contamination, the linear speed ratio Vd/Vp of the developing roller 2 B to the drum 1 must be 1.0 or above. However, an excessively great linear speed ratio causes the toner to deposit only on the trailing edge portion of a solid image, rendering the solid image defective. This stems from the fact that even after the trailing edge of a latent image has been developed, toner deposited on part of the developing roller 2 B newly facing the drum 1 due to the rotation of the roller 2 B deposits on the trailing edge within the developing region. It follows that as the nip width decreases, it reduces the period of time over which the trailing edge moves over the developing region and therefore excessive toner, thereby rendering the above occurrence inconspicuous. Nip widths less than 0.3 mm would practically cancel the scavenging effect and would cause the background of the drum 1 to be contaminated.
The illustrative embodiment obviates the above defective images and the background contamination of the drum 1 by defining a particular nip width.
Further, the illustrative embodiment confines a contact surface pressure P (gf/cm 2 ) between the drum 1 and the developing roller 2 B in the range of 1.0≦P≦5.0. Contact surface pressures above 5.0 gf/mm 2 increase the previously discussed scavenging effect and degrade the uniformity of a solid image. In addition, such pressures would increase the drive torque of the developing roller 2 B and make the rotation of the roller 2 B irregular, resulting in banding. Contact surface pressures below 1.0 gf/cm 2 would cancel the scavenging effect and would prevent the bite of the developing roller 2 B into the drum 1 from absorbing the dimensional error of the roller 2 B. The illustrative embodiment therefore obviates banding and therefore an irregular image.
(1) When the developer is pressured by 100 gf/cm 2 , the relation of 0.5 ρRt≦M≦1.2 ρRt holds between the volume mean particle size Rt (cm) of the developer, the amount M of the developer to deposit on the developer carrier, and the bulk density ρ (gf/cm 3 ). The developer deposits on the developer carrier in a substantially single layer and therefore has a uniform amount of charge. This surely obviates short charge that would cause the developer to fly about and contaminate the background of the image carrier. Adhesion of toner particles ascribable to cohesion does not occur despite aging. Further, the distance between the image carrier and the developer carrier is short enough to allow the developer to easily and faithfully migrate from the developer carrier toward a latent image formed on the image carrier, realizing a uniform solid image and a uniform halftone image. Moreover, the regulating means contacts the developer carrier via the developer and contacts the developer at its end or intermediate portion. This prevents the contact pressure of the regulating means from varying and thereby accurately determine the thickness of the single developer layer. Consequently, there can be surely obviated irregularities in the horizontal direction and banding.
(2) The nip width W between the image carrier and the developer carrier lies in the range of 0.3≦W≦3.0 (mm). This nip width W allows the developer carrier to scrape off the developer from the image carrier with an adequate scavenging effect, thereby insuring a uniform solid image and obviating the local concentration of the developer at the trailing edge of a solid image.
(3) The contact surface pressure P (gf/cm 2 ) between the image carrier and the developer carrier lies in the range of 1.0≦P≦5.0. This pressure P prevents the scavenging effect from increasing and making a solid image irregular and obviates banding ascribable to the irregular rotation of the developer carrier caused by an increase in the drive torque of the developer carrier. Further, the above pressure P prevents the scavenging effect from being cancelled and obviates irregular images by absorbing the dimensional error of the developer carrier with the bite of the developer carrier into the image carrier.
Third Embodiment
Referring to FIG. 12, a third embodiment of the present invention will be described. This embodiment is also directed toward the second object stated earlier. In FIG. 12, structural elements identical with the structural elements shown in FIG. 8 are designated by identical reference numerals. The surface of the drum 1 has a coefficient of friction μ lying in the range of 0.1≦μ≦0.4, as in the second embodiment.
The toner provided in the form of particles consists of a mixture of polyester, polyol, styrene-acryl or similar resin, a charge control agent (CCA) and a coloring agent, and silica, titanium oxide or similar substance applied to the particles. The coloring agent may be carbon black. Phtalocyanine Blue or quinacridone by way of example.
The particles have a mean particle size of 3 μmm to 12 μm, 7.5 μm in the illustrative embodiment. With such a mean particle size, it is possible to meet the demand for high resolution (1,200 dpi (dots per inch)) and to further reduce the particle size for even higher resolution. Further, the above kind of additive is applied to the surfaces of the toner particles consisting of polyester, polyol, styrene-acryl or similar resin, CCA, coloring agent and, if necessary, wax. The additive has a particle size ranging from 0.1 μm to 1.5 μm.
The developing roller 2 B is formed of rubber and has a preselected surface roughness. The rubber contains ferrite or similar magnetic material and magnetized and has its surface covered with a coating material, as in the previous embodiments.
One end of the metering blade 2 D is affixed to the casing 2 A. Assume a direction tangential to the position where the blade 2 D faces the developing roller 2 B. Then, the other end of the blade 2 D extends to the downstream side with respect to the direction of rotation of the developing roller 2 B with an inclination of 10° to 45° relative to the above tangential direction. The portion of the blade 2 D closer to the base end than to the free end contacts the developing roller 2 B. The blade 2 D is formed of SUS304 or similar metal and provided with a thickness of 0.1 mm to 0.15 mm. The length of the blade 2 D between the opposite ends is 10 mm to 15 mm. The blade 2 D contacts the developing roller 2 B with a pressure of 5 gf/cm to 50 gf/cm.
In the illustrative embodiment, assuming that the developing roller 2 B has hardness of 30° (JIS A scale), then the metering blade 2 D is formed of 0.1 mm thick SUS and provided with a contact pressure of 20 gf/cm. In this condition, the target amount of toner to deposit on the developing roller 2 B is 0.4 mg/cm 2 to 0.8 mg/cm 2 . In this case, the amount of charge to depot on the toner is between −8 μC/g and −30 μC/g. The developing roller 2 B contacts a latent image formed on the drum 1 via the toner layer to thereby develop the latent image.
By so limiting the length of the metering blade 2 D, it is possible to prevent the apparatus from being bulky or prevent the blade from easily oscillating due to an excessive length. The oscillation of the blade 2 D would prevent the toner layer on the developing roller 2 B from being uniform in thickness. Irregular deposition of toner would, in turn, render irregular image density conspicuous in the resulting image. Further, by limiting the contact pressure, it is possible to prevent the amount of charge to deposit on the toner from increasing due to the short deposition of the toner on the developing roller 2 B. The short deposition is apt to occur when the contact pressure is above the upper limit. This is successful to obviate the short transfer of the toner to the drum 1 and therefore short image density. In addition, the toner is prevented from being conveyed past the metering blade 2 D in the form of lumps and rendering the resulting image defective. This is apt to occur when the contact pressure is below the lower limit.
Coil springs, leaf springs or similar pressing means press the developing roller 2 B against the drum 1 via the toner layer. In the illustrative embodiment, when the developing roller 2 B has hardness (HS) of 30° (JIS A scale), the contact pressure is selected to be 2 gf/mm to 6 gf/mm. To guarantee the uniform density of a solid image, as many pressing means as possible should preferably be arranged in the axial direction of the developing roller 2 B for reducing irregular contact between the roller 2 B and the drum 1 .
The above contact pressure has influence on the uniform development of a solid image and the prevention of background contamination and is set on the basis of the following results of experiments. FIG. 13 is a table showing a relation between hardness and contact pressure and the occurrence of defective images (non-uniform solid image and background contamination) determined by experiments. As shown, the developing ability was too low to implement a sufficient amount of development when the contact pressure was below the lower limit of the above range (see the range indicated by oblique lines extending rightward downward). When the contact pressure was above the upper limit, the scavenging force of the developing roller 2 B was increased while the toner layer was compressed and caused to cohere. Consequently, the toner transferred to the drum 1 was scraped off or left on the developing roller 2 in the cohered condition, resulting in defective images including solid images with irregular density. When the contact pressure lies in the above range for the above hardness of the developing roller 2 B, uniform images with high density are achievable.
The fluidity of the toner is a parameter having influence on the deposition of the toner on the drum 1 . A loose apparent specific gravity is an index for this parameter. In the illustrative embodiment, the loose apparent specific gravity is selected to be 0.35 g/cm 2 or above. FIG. 14 lists the results of experiments conducted with different values of loose apparent specific gravity for determining the reproducibility of a halftone image. As shown, toner A and toner B respectively had loose apparent densities of 0.3 and 0.42. The developing roller 2 B was pressed against the drum 1 by a contact pressure of 6 gf/mm and rotated at a linear velocity ratio of 1.2 to the drum 1 so as to form a halftone image. For the experiments, use was made of Powder Tester Type PT-N available from HOSOKAWA MICRON CORP. In FIG. 4, a circle and a cross indicate high reproducibility and low reproducibility, respectively. While loose apparent density indicates the degree of fluidity when a packing ratio is measured, it increases with an increase in fluidity.
FIG. 15 demonstrates how a halftone image becomes non-uniform. Generally, development is effected by forces acting between toner and a latent image. Assume that a non-electrostatic adhering force F t,p acting between the toner and a photoconductive drum and a Coulomb force F q,a acting on the toner are the forces to act on the toner. The toner migrates toward a latent image and develops it when the sum of the above forces is greater than the sum of an adhering force F t,t acting between toner particles and a non-electrostatic adhering force F t,r acting between the toner and a developing roller:
F
t,p
+F
q,a
>F
t,t
+F
t,r
On the other hand, assume that the contact pressure increases the cohering force between toner particles when the metering blade 2 D regulates the toner layer or when a latent image on the drum 1 is developed. Then, the above adhering force F t,t between toner particles locally increases and prevents part of the toner from migrating, resulting in the local omission of an image.
Forces shown in FIG. 15 and including the above forces are listed below:
Forces Perpendicular to Circumference of Developing Roller 2 B
F t,p : non-electrostatic adhering force acting between toner and drum
F q,a : Coulomb force acting on toner
F t,t : adhering force acting between toner
F t,r : non-electrostatic adhering force acting between toner and developing roller 2 B
Forces Perpendicular to Developing Direction
Fμ t,p : frictional force acting between toner and drum 1 (μ t,p denoting coefficient of friction)
Fμ t,t : frictional force between toner (μ t,t denoting coefficient of friction)
Fμ t,r : frictional force acting between toner and developing roller 2 B (μ t,r denoting coefficient of friction)
In FIG. 15, when the adhering force F t,t between the toner particles increases, the cohering force between the particles increases and obstructs the migration of the particles to the drum 1 .
In light of the above, the illustrative embodiment uses additives for regulating the cohering force of toner ascribable to the adhering force acting between toner particles. Specifically, the current toner contains 0.2 wt % of silica and 0.3 wt % of titanium oxide. For toner B shown in FIG. 14, the illustrative embodiment selects 0.5 wt % of silica and 1 wt % of titanium oxide that are greater in ratio than the additives of toner A. With these additives, it is possible to lower the cohering force acting between toner particles and therefore to prevent toner particles from forming lumps. The toner can therefore contact the drum 1 in a loosened condition, insuring uniform development and uniform transfer characteristic.
Further, the following experiments were conducted to determine a relation between the sphericality of toner particles and the reproducibility of a halftone image. FIG. 16 shows the results of experiments. Specifically, how the reproducibility of a halftone image is effected by the sphericality of toner particles was determined on the assumption that the sphericality of true sphere was 1. As shown in FIG. 16, toner C and toner D respectively had sphericality of 0.88 and sphericality of 0.96. The developing roller 2 B was pressed against the drum 1 by a contact pressure of 6 gf/mm and rotated at a linear velocity ratio of 1:2 to the drum 1 for forming a halftone image. 0.6 wt % of silica was used as an additive. As FIG. 16 indicates, for a given amount of additive, the higher sphericality increases a covering ratio corresponding the amount of deposition of an additive that varies in accordance with the surface area of a toner particle, which in turn varies in accordance with sphericality. As a result, the adhering force between toner particles increases little despite the contact pressure when the metering blade 2 D forms a thin layer or during development of a latent image. This promotes uniform development and thereby enhances the reproducibility of a halftone image. To produce spherical toner particles, there may be used polymerization or a method that heats pulverized toner particles for restoring the surfaces of the particles to the original state.
As stated above, by controlling the amounts of additives and the configuration of toner particles, it is possible to reduce the cohering force to act between the toner particles and therefore to insure a uniform, dense image even when a latent image has low contrast.
FIG. 17 shows a relation between the developing roller 2 B and the metering blade 2 D shown in FIG. 12 . As shown, the developing roller 2 B is implemented as a magnetic roller having an outside diameter of 16 mm and including an elastic layer and a surface layer one of which contains a magnetic material. The developing roller 2 B has sixty magnetic poles. The casing 2 A stores a mixture of toner and magnetic particles P each having a size of 100 μmm to 300 μmm. The magnetic particles P should preferably be covered with, e.g., silicone resin. The free end of the metering blade 2 D is spaced from the circumference of the developing roller 2 B by a distance or height l. The size of each magnetic particle P is greater than the height l. Therefore, when the magnetic particles P contact the toner particles not regulated by the metering blade 2 D, the magnetic particles P can scrape off a small amount of toner particles. In addition, the particles P existing between the toner particles can loosen the toner particles to thereby obviate cohesion.
Why the magnetic particles P are mixed with the toner particles will be described more specifically. Factors that increase the adhering force to act between the toner particles are the fluidity of toner (loose apparent density), the contact pressure between the metering blade 2 D and the developing roller 2 B, and the contact pressure between the drum 1 and the developing roller 2 B, as stated earlier. The toner is fed to the developing roller 2 B by way of the feed roller 2 C in order to feed a sufficient amount of toner even to a low contrast image while insuring the development of a solid image. At this instant, the amount of toner to deposit on the developing roller 2 B sometimes exceeds 1 mg/cm 2 . As a result, the contact pressure between the metering blade 2 D and the developing roller 2 B and therefore the adhering force acting between the toner particles increases. In this respect, the magnetic toner particles P contacting part of the toner particles not regulated are successful to crape off part of such toner particles while loosening the toner particles. It follows that when the above contact pressure is constant, the adhering force between the toner particles can be reduced in accordance with the decrease in the degree of cohesion.
Because the developing roller 2 B is magnetic, the magnetic particles P are conveyed by the roller 2 B to the inlet between the metering blade 2 D and the developing roller 2 B. At this instant, the magnetic particles P and toner particles are agitated together and charged by friction. Consequently, the toner particles deposit on the magnetic particles P and scraped off thereby.
Part of the toner particles and magnetic particles P is prevented from advancing toward the position where the developing roller 2 B and metering blade 2 D face each other by the blade 2 D. This part of particles drops onto the feed roller 2 C or into the casing 2 A because the size of the magnetic particles P is greater than the height of the above inlet. Moreover, the particles obstructed by the metering blade 2 D are not passed through the position where the blade 2 D contacts the developing roller 2 B, because of the sufficient contact pressure (2.0 gf/mm). At this position, the particles P scraped off by the metering blade 2 D drop, due to gravity, to the position where the developing roller 2 B and feed roller 2 C contact each other, so that the surface layer of the drum 1 is protected from damage.
In summary, the illustrative embodiment has the following various unprecedented advantages (1) through (3).
(1) The developer has a loose apparent density selected to be 0.35 or above in order to reduce the cohering force acting between the particles of the developer. The developer can therefore deposit on the image carrier in a loosened condition and therefore insures a uniform halftone image and a uniform image transfer characteristic.
(2) Sphericality is used to define the configuration of each developer particle and selected to be 90% or above with respect to true sphericality. Therefore, for a given amount of additive, higher sphericality increases a covering ratio corresponding the amount of deposition of an additive that varies in accordance with the surface area of a toner particle, which in turn varies in accordance with sphericality. As a result, the adhering force between the toner particles increases little. This promotes uniform development and thereby enhances the reproducibility of a halftone image.
(3) The developer contains a plurality of particles, particularly magnetic particles having a size greater than the distance between the regulating member and the image carrier. The magnetic particles reduce the adhering force to act between the toner particles and thereby prevent the developer from forming lumps. This is also successful to promote uniform development and to enhance the reproducibility of a halftone image.
Various modifications will become possible for those skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof.
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An image forming apparatus of the type which develops a latent image on an image carrier with toner stored in a developing unit and transferring the resulting toner image to a recording medium. The developing unit includes a developer carrier which contacts the image carrier at least at two spaced apart points with a gap being formed between the at least two points of contact. A moving mechanism will move opposite ends of the developer carrier independent distances relative to one another so as to eliminate the gap and establish full contact between the image carrier surface and developer carrier surface.
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This application is a division of application Ser. No. 08/194,712, filed Feb. 10, 1994, now abandoned.
FIELD OF THE INVENTION
This invention relates to a beta-fructofuranosidase enzyme food supplement composition, which alleviates gastrointestinal distress caused by ingested food containing the oligosaccharides raffinose, stachyose and verbascose. In one embodiment, the enzyme food supplement composition of this invention comprises a beta-fructofuranosidase enzyme, a cellulase enzyme and a hemicellulase enzyme. More particularly, the beta-fructofuranosidase enzyme food supplement composition of this invention comprises a beta-fructofuranosidase enzyme, a cellulase enzyme, a hemicellulase enzyme, a lipase enzyme and an acid protease enzyme.
This invention also relates to a method of alleviating gastrointestinal distress in the gastrointestinal system of a human being, which distress is caused by ingested food containing the oligosaccharides raffinose, stachyose and verbascose. In one embodiment, the method of this invention comprises the step of ingesting a beta-fructofuranosidase enzyme food supplement composition comprising a beta-fructofuranosidase enzyme, a cellulase enzyme and a hemicellulase enzyme, to convert the oligosaccharides raffinose, stachyose and verbascose contained in ingested food to reducing sugars. The beta-fructofuranosidase enzyme converts these oligosaccharides, which cause gastrointestinal distress, to reducing sugars which are easily digested by the endogenous enzymes in the gastrointestinal system. More particularly, the method of alleviating gastrointestinal distress of this invention comprises the step of ingesting a beta-fructofuranosidase enzyme food supplement composition comprising a beta-fructofuranosidase enzyme, a cellulase enzyme, a hemicellulase enzyme, a lipase enzyme and an acid protease enzyme, to convert the oligosaccharides raffinose, stachyose and verbascose contained in ingested food to reducing sugars.
BACKGROUND OF THE INVENTION
The subject beta-fructofuranosidase enzyme food supplement composition was invented to meet the needs of the numerous people who needlessly suffer from gastrointestinal discomfort and flatulence because of the difficulty they have in digesting the oligosaccharides raffinose, stachyose and verbascose, which are known as alpha-galactosyl oligosaccharides, and are present in various foods such as legumes, bran, cruciferous vegetables, onions, garlic and some fruits. Because these oligosaccharides are not digestible by enzymes endogenous to a human's gastrointestinal system, they pass intact to the large intestine, where they are consumed by putrefactive bacteria such as Clostridia and E. coli and evolve as the metabolic by-product gases carbon dioxide and hydrogen as well as noxious methane. Even though the percentage of the oligosaccharides raffinose, stachyose and verbascose in these types of foods may seem small (for example, approximately only two percent are found in a prime offender, refried beans), waste gases can still be produced in sufficient volumes to cause gastrointestinal cramping and discomfort, as well as flatulence, that often accompany the intake of ingested foods containing these oligosaccharides. The beta-fructofuranosidase enzyme of the present invention is able to convert these offending oligosaccharides into the simpler, digestible sugars, such as fructose, which are known as reducing sugars, thereby alleviating gastrointestinal distress.
Prior to the present invention, to alleviate the gastrointestinal problems caused by ingesting foods containing these offending oligosaccharides people had the choice of either avoiding these foods entirely or using a food additive or an enzyme food supplement composition which contained the enzyme alpha-galactosidase as the only active ingredient.
A liquid product sold under the trademark BEANO by AkPharma has been described as an enzyme or food additive that reduces or eliminates the intestinal gas produced when foods such as beans, broccoli, bran and other vegetables and grains that are a staple in healthy low-fat, high-fiber diets, are eaten. That liquid food additive BEANO product contains the enzyme alpha-galactosidase obtained from Aspergillus niger. The alpha-galactosidase enzyme contained in the BEANO product works in a different manner than the beta-fructofuranosidase enzyme contained in the enzyme food supplement composition of the present invention. The beta-fructofuranosidase enzyme reduces the oligosaccharides of raffinose, stachyose and verboscose by converting the fructofuranose portion of the molecule to fructose. The alpha-galactosidase enzyme reacts with the galactopyranose portion of the raffinose, stachyose and verbascose molecules, but leaves the glucopyranose frustofuranose portion of those molecules intact.
The additional enzymes contained in the compositions of the present invention--the cellulase, hemicellulase, lipase and acid protease enzymes--are believed to contribute to the further alleviation of gastrointestinal distress by enhancing the conversion of oligosaccharides to reducing sugars in the following manner.
The cellulase and hemicellulase enzymes of the enzyme food supplement compositions of this invention degrade the cellulosic and hemicellulosic constituents contained in the plant cell walls of the ingested food. This degradation leads to the release of oligosaccharides contained in the plant cells, thereby making these oligosaccharides available for conversion to reducing sugars by the beta-fructofuranosidase enzyme of the present invention. Without the presence of the cellulase and hemicellulase enzymes in the enzyme food supplement composition of the present invention, the plant cell walls contained in ingested food would not be degraded by the digestive enzymes endogenous to the gastrointestinal tract of a human being. The cellulase enzyme is important because it degrades the primary plant cell wall, which if passed to the colon as intact plant cells can be attacked by putrefactive bacteria such a C. perfringens, which ferment the contents of the plant cell, causing gastric distress. The hemicellulase enzyme is important because it breaks the structure of xylans and related compounds, which are usually associated with cellulose and lignin in leguminous foods. This enzymatic activity helps to free the cellulose for hydrolysis by cellulase. Therefore, the presence of the cellulase and hemicellulase enzymes of the enzyme food supplement compositions of this invention degrade cellulosic and hemicellulosic constituents contained in the ingested food, to attain an enhanced quantity of reducing sugars through oligosaccharide conversion, thereby further alleviating gastrointestinal distress.
The optional lipase enzyme is important because many recipes containing legumes, such as refried beans, also contain large amounts of fat, and the lipase enzyme aids in the digestion of fats or lipids. The maldigestion of such fats or lipids can cause or aggravate heartburn, hiatus hernia and esophageal reflux. Ingested lipids can also coat ingested food particles and limit their ability to interact with the other enzymes, in particular the beta-fructofuranosidase enzyme of the present invention. This coating effect is diminished by enzymatic hydrolysis of the fats or lipids contained in ingested foods.
The optional acid protease enzyme of the present invention is important for several reasons. The acid protease enzyme degrades proteinaceous trypsin inhibitor and alpha-amylase inhibitor, which interfere with normal digestion, in addition to aiding in general protein digestion. In addition, the acid protease enzyme of the present invention helps to break down lipoproteins and glycoproteins contained in foods like legumes.
Because foods containing the troublesome oligosaccharides raffinose, stachyose and verbascose also contain lipids and lipoproteins which tend to coat the ingested food and thereby hinder the beta-fructofuranosidase enzyme from contacting these oligosaccharides and thereby converting them to reducing sugars, an additional advantage of the present invention is the presence of a lipase enzyme to hydrolyze the ingested lipids coating ingested food and the presence of an acid protease enzyme to deconjugate the ingested lipoproteins coating ingested food, to attain an enhanced quantity of reducing sugars through oligosaccharide conversion.
The enzyme food supplement compositions of this invention are of value to any one who has suffered gastrointestinal distress caused by ingesting foods containing the oligosaccharides raffinose, stachyose and verbascose.
To the best of applicant's knowledge, the presently claimed beta-fructofuranosidase enzyme food supplement compositions are the first such compositions that seek to alleviate the problem of gastrointestinal distress by utilizing the unique combination of a beta-fructofuranosidase enzyme, a cellulase enzyme and a hemicellulase enzyme, and optionally a lipase enzyme and an acid protease enzyme.
The major advantage of the present invention is that the unique combination of enzymes is able to convert, effectively in the gastrointestinal system of a human being, undigestible oligosaccharides to digestible reducing sugars, thereby alleviating gastrointestinal distress which is normally associated with the ingestion of foods containing such oligosaccharides.
These and additional objects and advantages of the present invention are shown from the description below.
SUMMARY OF THE INVENTION
This invention relates to a beta-fructofuranosidase enzyme food supplement composition, which alleviates gastrointestinal distress caused by ingested food containing oligosaccharides, said composition comprising a beta-fructofuranosidase enzyme, a cellulase enzyme and a hemicellulase enzyme.
This invention further relates to a beta-fructofuranosidase enzyme food supplement composition, which alleviates gastrointestinal distress caused by ingested food containing oligosaccharides, said composition comprising a beta-fructofuranosidase enzyme, a cellulase enzyme, a hemicellulase enzyme, a lipase enzyme and an acid protease enzyme.
This invention still further relates to the above-mentioned beta-fructofuranosidase enzyme food supplement compositions wherein the beta-fructofuranosidase enzyme is obtained from Saccharomyces cerevisiae, the cellulase enzyme is obtained from a member selected from the group consisting of Aspergillus niger and Trichoderma viride (reesei), the hemicellulase enzyme is obtained from Aspergillus niger, the lipase enzyme is obtained from Aspergillus niger, and the acid protease enzyme is obtained from Aspergillus niger var. macrosporus. In a method of use embodiment, the present invention relates to a method of alleviating gastrointestinal distress in the gastrointestinal system of a human being, which distress is caused by ingested food containing oligosaccharides, said method comprising the step of ingesting a beta-fructofuranosidase enzyme food supplement composition comprising a beta-fructofuranosidase enzyme, a cellulase enzyme and a hemicellulase enzyme, to convert oligosaccharides contained in the ingested food to reducing sugars. The beta-fructofuranosidase enzyme of the enzyme food supplement composition converts the oligosaccharides to reducing sugars. The cellulase and hemicellulase enzymes of the enzyme food supplement composition degrade cellulosic and hemicellulosic constituents contained in the ingested food, to attain an enhanced quantity of reducing sugars through oligosaccharide conversion.
In another method of use embodiment, the present invention further relates to a method of alleviating gastrointestinal distress in the gastrointestinal system of a human being, which distress is caused by ingested food containing oligosaccharides, said method comprising the step of ingesting an enzyme food supplement composition comprising a beta-fructofuranosidase enzyme, a cellulase enzyme, a hemicellulase enzyme, a lipase enzyme and an acid protease enzyme, to convert oligosaccharides contained in the ingested food to reducing sugars. The beta-fructofuranosidase enzyme of the enzyme food supplement composition converts the oligosaccharides to reducing sugars. The cellulase and hemicellulase enzymes of the enzyme food supplement composition degrade cellulosic and hemicellulosic constituents contained in the ingested food, the lipase enzyme of the enzyme food supplement composition hydrolyzes ingested lipids coating the ingested food, and the acid protease enzyme of the enzyme food supplement composition deconjugates ingested lipoproteins coating the ingested food, to attain an enhanced quantity of reducing sugars through oligosaccharide conversion.
DETAILED DESCRIPTION OF THE INVENTION
The beta-fructofuranosidase enzyme food supplement composition in accordance with this invention includes a beta-fructofuranosidase enzyme, a cellulase enzyme and a hemicellulase enzyme.
A beta-fructofuranosidase enzyme is defined as an invertase enzyme which catalyses the hydrolysis of sucrose into fructose and glucose and is characterized by its ability to hydrolyze raffinose. Since sucrose is both a beta-fructofuranoside and an alpha-glucoside, it is important to note that the beta-fructofuranosidase enzyme attacks the sucrose molecule from the fructose, not the glucose, end of the molecule. Beta-fructofuranosidase enzymes are generally obtained from yeast, and a particularly preferred beta-fructofuranosidase enzyme is obtained from Saccharomyces cerevisiae. Although the beta-fructofuranosidase enzyme can be obtained by culturing the Saccharomyces Cerevisiae organism, then extracting and purifying the enzyme by known and conventional techniques, the applicant has found it more efficient to purchase the enzyme from any one of the following sources: Bio-Cat, Inc., Industrial Drive, Louisa, Va. 23093; Amano International Enzyme Company, Inc., 250 East Zion Crossroads, Troy, Va. 22974. The invention is not, however, to be limited by the source of the beta-fructofuranosidase enzyme.
A cellulase enzyme is defined as an enzyme which is capable of degrading cellulase. The cellulase enzymes that can be utilized include those obtained from Aspergillus niger or Trichoderma reesei. Trichoderma reesei is also referred to as Trichoderma viride. Although the use of a cellulase enzyme from a fungal source is preferred, the invention is not, however, to be limited by the source of the cellulase enzyme. A hemicellulase enzyme is defined as an enzyme which is capable of hydrolyzing specific types of hexosans and pentosans, including more or less complex mannans, galactans and xylans. A hemicellulase enzyme that can be utilized includes the hemicellulase enzyme obtained from Aspergillus niger. Notwithstanding that the use of a hemicellulase enzyme from a fungal source is preferred, the invention is not, however, to be limited by the source of the hemicellulase enzyme. Although both the cellulase and hemicellulase enzymes can be obtained by culturing an organism, then extracting and purifying the enzyme by known and conventional techniques, the applicant has found it more efficient to purchase the cellulase and hemicellulase fungal enzymes from any one of the following sources: Bio-Cat, Inc., Industrial Drive, Louisa, Va. 23093; Amano International Enzyme Company, Inc., 250 East Zion Crossroads, Troy, Va, 22974.
The beta-fructofuranosidase enzyme, cellulase enzyme and hemicellulase enzyme may be used, in accordance with the subject invention, in the following concentrations: for the beta-fructofuranosidase enzyme, a concentration of at least 25,500 Sumner units per gram of the composition; for the cellulase enzyme, a concentration of at least 12,000 FPU (Filter paper units) per gram of the composition; and for the hemicellulase enzyme, a concentration of at least 250 HCU (Hemicellulase units) per gram of composition. The amount of enzyme is not critical. However, for reasons of economics, an excessive quantity of enzyme should be avoided, and for reasons of utility, at least the minimum amount to produce satisfactory results should be used.
In another embodiment of this invention, the beta-fructofuranosidase enzyme food supplement composition includes a beta-fructofuranosidase enzyme, a cellulase enzyme, a hemicellulase enzyme, a lipase enzyme and an acid protease enzyme.
The beta-fructofuranosidase enzyme, cellulase enzyme and hemicellulase enzyme of this embodiment are as defined above. The lipase enzyme is defined as an enzyme which is capable of hydrolyzing lipids. The lipase enzyme that is preferred is obtained from Aspergillus niger. Although the use of a lipase enzyme from the fungal source Aspergillus niger is preferred, the invention is not, however, to be limited by the source of the lipase enzyme. Although the lipase enzyme can be obtained by culturing the Aspergillus niger organism, then extracting and purifying the enzyme by known and conventional techniques, the applicant has found it more efficient to purchase the lipase enzyme from any one of the following sources: Bio-Cat, Inc., Industrial Drive, Louisa, Va. 23093; Amano International Enzyme Company, Inc., 250 East Zion Crossroads, Troy, Va. 22974.
An acid protease enzyme is defined as an enzyme, which is capable of breaking down proteins and their degradation products, polypeptides and peptides, by hydrolysis, and is active in a pH environment ranging from a pH of 2 to a pH of 8, with the optimum pH being around 6. The acid protease enzymes that can be utilized include those obtained from Rhizopus niveus and Aspergillus niger var. macrosporus. Although the enzyme can be obtained by culturing the above-mentioned organisms, then extracting and purifying the enzyme by known and conventional techniques, the applicant has found it more efficient to purchase the acid protease enzyme from any one of the following sources: Bio-Cat, Inc., Industrial Drive, Louisa, Va. 23093; Amano International Enzyme Company, Inc., 250 East Zion Crossroads, Troy, Va. 22974. The invention is not, however, to be limited by the source of the lipase enzyme.
The beta-fructofuranosidase enzyme, cellulase enzyme, hemicellulase enzyme, lipase enzyme and acid protease enzyme may be used, in accordance with this embodiment of the subject invention, in the following concentrations: for the beta-fructofuranosidase enzyme, a concentration of at least 25,500 Sumner units per gram of the composition; for the cellulase enzyme, a concentration of at least 12,000 FPU (Filter paper units) per gram of the composition; for the hemicellulase enzyme, a concentration of at least 250 HCU (Hemicellulase units) per gram of composition; for the lipase enzyme, a concentration of at least 750 FIP units per gram of composition; and for the acid protease enzyme, a concentration of at least 500 Acid protease units per gram of composition. The amount of enzyme is not critical. However, for reasons of economics, an excessive quantity of enzyme should be avoided, and for reasons of utility, at least the minimum amount to produce satisfactory results should be used.
Another ingredient which is commonly added, although not essential, to the enzyme food supplement compositions of the present invention is a carrier material. Suitable carrier materials include potato starch, maltodextrins, modified starches, direct compression tablet excipients such as dicalcium phosphate, calcium sulfate and sucrose. A particularly preferred carrier ingredient is the 10 DE Maltrin M100 maltodextrin from Grain Processing Corporation. Carriers can be added in concentrations ranging from 50 to 95 weight percent of the total composition.
Various other additives which are conventionally added to enzyme food supplement compositions, such as preservatives and the like, may be utilized.
The beta-fructofuranosidase enzyme food supplement composition of the present invention was designed for use as a tablet, capsule or powder food supplement, to be taken with foods containing oligosaccharides.
One method of ingredient incorporation for the beta-fructofuranosidase enzyme food supplement compositions, in accordance with this invention, and as used to formulate the examples is as follows:
EXAMPLES
In one embodiment, a typical beta-fructofuranosidase enzyme food supplement composition of the present invention comprises the following ingredients: (1) 5.0 weight percent of beta-fructofuranosidase (ex Saccharomyces cerevisiae) containing approximately 85,000 Sumner units per gram of beta-fructofuranosidase obtained from Bio-Cat, Inc.; (2) 5.0 weight percent of cellulase (ex Trichoderma viride (reesei)) containing approximately 24,000 FPU per gram of cellulase enzyme obtained from Bio-Cat, Inc.; and (3) 5.0 weight percent of hemicellulase (ex Aspergillus niger) containing approximately 500 HCU per gram of hemicellulase enzyme, also obtained from Bio-Cat, Inc. The remainder of the composition consists of 85.0 weight percent of potato starch. The weight percents are weight percentages of the total composition. The 85,000 Sumner units per gram for the beta-fructofuranosidase enzyme, the 24,000 FPU per gram for the cellulase enzyme, and the 500 HCU per gram for the hemicellulase enzyme are standard units of enzyme activity per gram of individual enzyme, as explained in more detail below.
In another embodiment, a typical beta-fructofuranosidase enzyme food supplement composition of the present invention comprises the following ingredients: (1) 60.0 weight percent of beta-fructofuranosidase (ex Saccharomyces cerevisiae) containing approximately 85,000 Sumner units per gram of beta-fructofuranosidase enzyme obtained from Bio-Cat, Inc.; (2) 10.0 weight percent of cellulase (ex Trichoderma viride (reesei)) containing approximately 240,000 FPU per gram of cellulase enzyme obtained from Bio-Cat, Inc.; (3) 10.0 weight percent of hemicellulase (ex Aspergillus niger) containing approximately 5,000 HCU per gram of hemicellulase enzyme, also obtained from Bio-Cat, Inc.; (4) 15.0 weight percent of lipase (ex Aspergillus niger) containing approximately 100,000 FIP units per gram of lipase, also obtained from Bio-Cat, Inc.; and (5) 5.0 weight percent of acid protease (ex Aspergillus niger var. macrosporus) containing approximately 20,000 Acid protease units per gram of acid protease enzyme, also obtained from Bio-Cat, Inc. The weight percents are weight percentages of the total composition. The 85,000 Sumner units per gram for the beta-fructofuranosidase, the 240,000 FPU per gram for the cellulase enzyme, the 5,000 HCU per gram for the hemicellulase enzyme, the 100,000 FIP units per gram for the lipase enzyme, and the 20,000 Acid protease units per gram for the acid protease enzyme are standard units of enzyme activity per gram of individual enzyme as explained below. The total enzyme activity per gram of this particular embodiment of the invention described in the above example is as follows: beta-fructofuranosidase invertase enzyme: 51,000 Sumner u/gram; cellulase enzyme: 24,000 FPU/gram; hemicellulase enzyme: 500 HCU/gram; lipase enzyme: 15,000 FIP u/gram; and acid protease enzyme: 1,000 u/gram.
A Sumner unit is defined as that quantity of enzyme required, under standard conditions, which forms 1 mg of invert sugar from 325 mg of sucrose in 5 minutes at 25° C. An invertase enzyme breaks down sucrose with the formation of invert sugar. The formation of invert sugar under standard conditions is determined with dinitrosalicylic acid-phenol reagent. A FPU unit (Filter Paper Unit) is defined as that quantity of enzyme required, under the conditions of the assay stated in Ghose, T. K., Measurement of Cellulase Activity, IUFAC Commission on Biotechnology (1984). The cellulase in the sample hydrolyzes the substrate which is filter paper, and the reducing sugars thus released are assayed spectrophotometrically using dinitrosalicylic acid. An HCU unit (Hemicellulase Unit) is that activity that will produce a relative fluidity change of 1 over a period of five minutes in a defined locust bean gum substrate under the conditions specified in the assay stated in the above-referenced texts, section Hemicellulase Activity, pp. 490-491. The assay is based on the enzymatic hydrolysis of the interior glucosidic bonds of a defined locust bean gum substrate at pH 4.5 and 40° C. The corresponding reduction in substrate viscosity is determined with a calibrated viscometer. One FIP unit of enzyme activity is the amount contained in a standard preparation which liberates one microequivalent of fatty acid per minute under the conditions of the assay. Pharmaceutical Enzymes, Microbial Lipases, § 8, pp. 210-213. The specific activity is expressed in international FIP units per mg of enzyme preparation. One unit of Acid protease activity is defined as the quantity of the enzyme to produce amino acids equivalent to 100 units of tyrosine in 1 ml of filtrate per 60 minutes at 37° C.
In order to make a beta-fructofuranosidase enzyme food supplement composition in accordance with this invention, the purified enzymes, which were purchased from Bio-Cat, Inc., were dry-blended until a uniform mixture was obtained.
The present enzyme food supplement composition is ingested in the same manner as any food product and preferably taken immediately after or during ingestion of the food containing the oligosaccharides raffinose, stachyose and verbascose.
The beta-fructofuranosidase enzyme food supplement compositions of the present invention may be illustrated by way of the above examples which is presented for illustration and not intended to be limiting to the scope of the invention. The invention is not to be limited except as set forth in the following claims.
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This invention relates to a beta-fructofuranosidase enzyme food supplement composition, which alleviates gastrointestinal distress caused by ingested food containing oligosaccharides, comprising a beta-fructofuranosidase enzyme, a cellulase enzyme and a hemicellulase enzyme. More particularly, the enzyme food supplement composition of this invention comprises a beta-fructofuranosidase enzyme, a cellulase enzyme, a hemicellulase enzyme, a lipase enzyme and an acid protease enzyme. This invention also relates to a method of alleviating gastrointestinal distress in the gastrointestinal system of a human being, which distress is caused by ingested food containing oligosaccharides, the method comprising the step of ingesting a beta-fructofuranosidase enzyme food supplement composition comprising a beta-fructofuranosidase enzyme, a cellulase enzyme and a hemicellulase enzyme, to convert oligosaccharides contained in the ingested food to reducing sugars. More particularly, the method of alleviating gastrointestinal distress of this invention comprises the step of ingesting an enzyme food supplement composition comprising a beta-fructofuranosidase enzyme, a cellulase enzyme, a hemicellulase enzyme, a lipase enzyme and an acid protease enzyme, to convert oligosaccharides contained in the ingested food to reducing sugars.
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FIELD OF THE INVENTION
The invention relates to a keyboard device for an electronic musical instrument such as an electronic piano or an electronic organ.
BACKGROUND OF THE INVENTION
A conventional keyboard device for an electronic musical instrument is shown in FIG. 9. That keyboard device comprises a key b supported at its rear end for swinging movement about a shaft a mounted on a keyboard chassis, a hammer c disposed for swinging movement about a shaft a' so that it may be operated in association with key b during depression of the key, and a resilient member d resiliently engaged with key b at one end and with hammer c at the other end thereof and arranged to urge key b and hammer c respectively against the corresponding shafts.
The resilient member d of the keyboard device biases key b and hammer c in a swinging direction opposite to a direction of swinging movement occurring during depression of the key, i.e., in a returning direction.
The conventional keyboard device of FIG. 9 is disadvantageous in that the load characteristic, particularly the initial load on the key b, may be influenced by a dispersion in characteristic of the resilient member d, and in that it is difficult to provide a desired performance.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is to overcome the above-discussed problem with the prior art.
To achieve that object, the present invention provides a keyboard device for an electronic musical instrument comprising a key swingably supported with its rear end engaging a shaft mounted on a keyboard chassis, a hammer swingably disposed in engagement with a shaft mounted on the keyboard chassis so that it may be operated in association with the key during depression of the key, and a resilient member resiliently engaged at its opposite ends respectively with the key and the hammer to urge the key and the hammer against the shafts respectively, wherein the engaged positions of the resilient member on the key and the hammer are so set as to reduce the load exerted on the key by the resilient member to nearly zero by causing the resilient member to act on the hammer and the key to swing the hammer always in a returning direction and to swing the key always in the same swinging direction as during depression of the key, whereby the key is made to return by the swinging movement in the returning direction of the hammer by its own weight.
As a result of the structure of the keyboard device according to the present invention, even if there is a dispersion in characteristic of the resilient member for returning the key, the load characteristic, particularly the initial load on the key, cannot be influenced by such dispersion, and a desired characteristic can be easily provided.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiment of the present invention will now be described with reference to the accompanying drawings, wherein:
FIGS. 1 to 4 are diagrams which illustrate the principle of the present invention;
FIGS. 5 and 6 are graphical depictions of the equations for the load acting on the leading end of the key, with the weights of the key and hammer considered and not considered, respectively;
FIG. 7 is a side view, partly in section, of one embodiment of the present invention;
FIG. 8 is an exploded perspective view of an essential portion of the embodiment of FIG. 7;
FIG. 9 illustrates a principle of the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, a key 1 is swingably supported on a shaft 3, and a hammer 2 is swingably supported on a shaft 4. A resilient member 5, such as a leaf spring, is mounted between key 1 and hammer 2 to urge them against shafts 3 and 4, respectively. The resilient member 5 exerts a force on hammer 2 and key 1 to swing hammer 2 always in a returning direction and to swing key 1 always in the same swinging direction as that produced by depression of the key.
In FIG. 1, A denotes a center of gravity of key 1; B denotes a fulcrum of key 1; C denotes a center of gravity of hammer 2; D denotes a fulcrum of hammer 2; E denotes a point of loading on key 1; G1 and G2 denote points of engagement of resilient member 5 with hammer 2 and key 1, respectively; and H denotes a contact point of key 1 with hammer 2. As shown in FIG. 2, if the weight W K of key 1 is applied to the center of gravity A and the weight W L of hammer 2 is applied to the center of gravity C, and if an angle between a line L 4 connecting the center of gravity A of key 1 and the fulcrum B and a horizontal line is denoted by θ 4 , and an angle between a line L 5 connecting the center of gravity C of hammer 2 and the fulcrum D and the horizontal line is denoted by θ 5 , a force component W KT perpendicular to line L 4 of weight W K and a force component W LT perpendicular to line L 5 of weight W L are given by the following equations:
W.sub.KT =W.sub.K cos θ.sub.4 (1)
W.sub.LT =W.sub.L cos θ.sub.5 (2)
In FIG. 3, if an angle between a line L 1 connecting the contact point H and the fulcrum B and the horizontal line is denoted by θ 1 ; an angle between a line L 2 connecting the contact point H and the fulcrum D and the horizontal line is denoted by θ 2 ; an angle between a contact surface of key 1 with hammer 2 and the horizontal line is denoted by θ 3 ; a force of hammer 2 vertically acting on the contact surface of key 1 and hammer 2 is denoted by F M ; a component of force F M perpendicular to line L 2 is denoted by F L ; and a component of force F M perpendicular to line L 1 is denoted by F K , the following relations are established. ##EQU1##
Accordingly, the following relation is established: ##EQU2##
In FIG. 4, if a line connecting the points of engagement G 1 and G 2 is denoted by L 9 ; a line connecting the point of engagement G 1 and the fulcrum D is denoted by L 7 ; a line connecting the point of engagement G 2 and the fulcrum B is denoted by L 6 ; a force of resilient member 5 is denoted by F; a component of force F perpendicular to line L 7 is denoted by F TL ; a component of force F perpendicular to line L 6 is denoted by F TK ; an angle formed by line L 6 and the horizontal line is denoted by θ 6 ; an angle formed by line L 7 and the horizontal line is denoted by θ 7 ; and an angle formed by line L 9 and the horizontal line is denoted by θ 8 , the following equations are established:
F.sub.TK =F·cos(θ.sub.8 -θ.sub.6 -π/2)(6)
F.sub.TL =F·cos{π/2-(θ.sub.8 -θ.sub.7)}(7)
The equations for the balance of forces on the system of key 1 and hammer 2 derived from the above equations are as follows:
F.sub.f ·l.sub.8 +W.sub.KT ·l.sub.4 +F.sub.TK ·l.sub.6 =F.sub.K ·l.sub.1 (8)
F.sub.L ·l.sub.2 =F.sub.TL ·l.sub.7 +W.sub.LT ·l.sub.5 (9)
wherein l 8 , l 4 , l 6 , l 1 , l 2 , l 7 and l 5 are lengths of the line L 8 , L 4 , L 6 , L 1 , L 2 , L 7 and L 5 respectively, and F f is a load acting on the leading end of key 1. From equations (8) and (9), the following equation is established: ##EQU3## In addition, if the weights of key 1 and hammer 2 are ignored, the following equation is established: ##EQU4## If actual numerical values are introduced into equations (10) and (11), the values F f and F f ' are as shown in FIGS. 5 and 6, respectively.
When the weights of key 1 and hammer 2 are ignored, the load F f ' exerted on key 1 by resilient member 5 is always negative, as shown in FIG. 6, and can be lowered to almost zero by proper selection of the positions of engagement of resilient member 5 with key 1 and hammer 2. Thus, if this is done, only a small dispersion in resilient force of resilient member 5 is produced during initial loading on key 1 and hence, the load on key 1 may be determined by the weights of key 1 and hammer 2.
Referring to FIGS. 7 and 8, key 1 comprises a a wood key member 1a and a synthetic resin key member 1b coupled to the lower surface of wood key member 1a with its leading end aligned with a leading end of wood key member 1a. The lower surface of wood key member 1a is provided with a hole 8 into which a lateral-deflection blocking pin 7 (which will be described hereinafter) is fitted, and recesses 9 for coupling wood key member 1a and synthetic resin key member 1b. Synthetic resin key member 1b has the same width as wood key member 1a and a length greater than that of wood key member 1a, and its portion overlapping wood key member 1a is formed into an inverted U-shaped section by a top wall 10u and opposing sidewalls 11. Synthetic resin key member 1b has, at its leading end, a stopper 12 engaging a stopper 6a mounted on a keyboard chassis 6 and is provided at the top wall 10u with hole 13 into which lateral-deflection blocking pin 7 is fitted. Key member 1b is also provided at its upper surface with projections 14 for engagement with recesses 9 of key member 1a and at its lower surface, for example, with a pair of switch depressing projections 15. A portion of key member 1b projecting from a rear end of key member 1a is formed into a U-shaped section by opposing sidewalls 11 and a bottom wall 10d connecting the sidewalls, and includes, at its rear end, an end wall 16 connected to end edges of the opposing sidewalls 11 and an end edge of bottom wall 10d. A groove 17 is provided in an outer surface of end wall 16, and a recess 18 is provided at a lower end of that outer surface. Recess 18 is an engagement portion which engages shaft 3, which is mounted on keyboard chassis 6 to swingably support key 1. Thus, key 1 is swingably supported at its rear end on keyboard chassis 6 by the fitting of recess 18 of end wall 16 over the shaft 3.
Hammer 2 is intended to provide, even in an electronic musical instrument, the same key touch feeling as in a piano and is swingable due to a recess 19 provided at a lower portion in the vicinity of its front end being fitted over a shaft 4 mounted on keyboard chassis 6. A resilient member 5 is mounted in a bent manner to extend between an engaging recess 20 on an upper surface of hammer 2 in the vicinity of the front end thereof and an engaging recess 21 of key 1, so that key 1 and hammer 2 are urged against shafts 3 and 4 respectively by a resilient force of resilient member 5. The engaged positions of resilient member 5 to key 1 and hammer 2 are set so that resilient member 5 acts on hammer 2 and key 1 to always swing hammer 2 in a returning direction and to always swing key 1 in the swinging direction produced by depression of the key, so that a load exerted on key 1 by resilient member 5 may be approximately zero. Thus, key 1 is adapted to be urged upwardly and returned to an original position upon swinging movement of hammer 2 by its own weight in the returning direction. In addition, hammer 2 is adapted to be urged and swung by a lower surface 22 of top wall 10u, i.e., a contact surface 22 of key 1 with hammer 2 during depression of the key.
In FIGS. 7 and 8, reference numeral 23 denotes a deformable guide pin covered with a cover made of a flexible material, e.g., a plastic cover 24. Guide pin 23 has its base portion attached to keyboard chassis 6 and its leading end loosely fitted in groove 17 provided on the outer surface of end wall 16, so that changing of the direction of guide pin 23 causes key 1 to swing laterally, whereby the lateral inclination of key 1 is corrected. The lateral-deflection blocking pin 7 is formed to rise from an end face of keyboard chassis 6 and has a plastic cover 7a fitted over its outer periphery. Pin 7 is fitted in holes 8 and 13 in key 1. Reference numeral 25 denotes a key switch attached to keyboard chassis 6.
The foregoing description of the preferred embodiment of the invention is given for the purpose of illustration only. Structural modifications within the scope and spirit of the claimed invention will be obvious to one of ordinary skill in the art.
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A keyboard device has a key, a support for the key, the key being rotatably mounted on the key support, a hammer, a support for the hammer, the hammer being rotatably mounted on the hammer support, a resilient member for urging the key to swing in a direction which is the same as the direction of swinging of the key when the key is depressed and for urging the hammer to swing in a direction which is opposite to the direction of swinging of the hammer when the key is depressed. The resilient member has a first end coupled to the key and a second end coupled to the hammer.
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PRIORITY UNDER 35 U.S.C. 119(e) & 37 C.F.R. 1.78
This nonprovisional application claims priority based upon the following prior U.S. provisional patent application entitled: Cool Breeze presents “The Drinking Game, A**hole”, Application No. 60/809,321 filed May 30, 2006, in the name of David L. Breese, which is hereby incorporated by reference for all purposes.
FIELD OF THE INVENTION
The present invention relates to a game, more specifically but not by way of limitation, a game that utilizes a deck of playing cards, a rank establishing deck of cards, a hat and a game board to facilitate competition between a plurality of players.
BACKGROUND
The indulgence and participation in games has existed for centuries. Individuals have engaged in a variety of games over the centuries to stimulate competition, camaraderie and enjoyment. Many styles and types of games exist. One popular game that has remained popular is cards. A standard deck of cards consists of fifty two cards that are divided into four suits. Players utilize these cards to facilitate the playing of numerous different types of card games. While many methods of playing games utilize a deck of cards, there still exists a need for alternative card games to continue to provide entertainment for individuals engaging in card games.
Accordingly, there remains a need for a card game that provides an alternative to the existing methods of card games that currently exist.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a card game and a method of playing thereof wherein a plurality of players compete to win the right to determine the actions of another player utilizing at least one physical deck of cards.
A further object of the present invention is to provide a card game and a method of playing thereof wherein at the termination of the first round of the game one player will remain in possession of at least one playing card.
Another object of the present invention is to provide a card game and a method of playing thereof wherein the last player being in possession of playing cards at the termination of the first round will be required to wear a hat.
An additional object of the present invention is to provide a card game and a method of playing thereof that will further incorporate a game board.
It is a another object of the present invention to provide a card game that further incorporates a second round of play wherein all players not wearing the hat from the first round utilize the deck of cards to control the actions of the player wearing the hat.
To the accomplishment of the above and related objects the present invention may be embodied in the form illustrated in the accompanying drawings. Attention is called to the fact that the drawings are illustrative only. Variations are contemplated as being a part of the present invention, limited only by the scope of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be had by reference to the following Detailed Description and appended claims when taken in conjunction with the accompanying Drawings wherein:
FIG. 1 illustrates an exemplary embodiment of the decks of cards to be utilized in playing the present invention;
FIG. 2 illustrates an exemplary embodiment of a hat that is utilized during the play of the present invention; and
FIG. 3 illustrates an embodiment of a game board that is utilized during the play of the present invention.
DETAILED DESCRIPTION
Referring now to the drawing submitted herewith wherein the various elements depicted therein are not necessarily drawn to scale and in particular FIGS. 1-3 , there is illustrated a preferred embodiment of a card game 100 constructed according to the principles of the present invention.
The card game 100 comprises a first deck of cards 110 . The first deck of cards 110 include a traditional set of cards that have four suits, clubs, spades, diamonds and hearts with numerical values of two through ten and face cards consisting of ace, jack, queen, king. The first deck of cards 110 are completely dealt to the players engaged in the card game 100 . Although no particular amount of players are required, good results have been achieved utilizing approximately three to ten players to play the card game 100 . Subsequent to the dealing of the cards 115 contained within the first deck of cards 110 , the players engage in the first round of play. Each player's objective is to discard all of their cards prior to their opponents. This can be accomplished by engaging in numerous varieties of card value games. Although good results have been achieved utilizing a traditional set of 4 suited cards, it is contemplated to be within the scope of this invention that virtually any type of cards establishing a type of rank, value or order could be utilized.
More specifically but not by way of limitation, the players can display one card 115 at a time and the player displaying the card 115 with the lowest value, numeric or other, would lose the hand subsequently required to maintain possession of all of the card 115 displayed in that hand while the other player have won the right to discard the cards 115 displayed by them during the hand. In this example, an ace card would have higher value than a king which would have a higher value than a queen which would have a higher value than a jack. Cards 115 of higher numeric value win over cards 115 having a lower numeric value. At least one round of play would exist until only one player remains with cards 115 from the first deck of cards 110 in their possession.
Those skilled in the art will recognize that numerous techniques of establishing a method of playing in the first round utilizing the first deck of cards 110 could be established. More specifically but not by way of limitation, the first round could include traditional card games such as but not limited to blackjack, five card draw, war, or seven card stud. Additionally, prior to the commencement of the first round of play the players could decide on a wild card that would have a predetermined value. It is also further contemplated within the scope of the present invention that one deck of cards 115 could be provided to facilitate the playing of the card game 100 .
Subsequent to the first round of play a single player remains in possession of at least one of the cards 115 from the first deck of cards 110 . The player remaining in possession of at least one card 115 from the first round of play is subsequently required to be identified by wearing a hat 200 . While no particular type of hat 200 is required, it is desired within the scope of the present invention that the hat 200 have at least a portion 210 that resembles the human buttocks. The player who is wearing the hat 200 must continue to wear the hat 200 during the second round of play. During the second round of play the player identified by wearing the hat 200 is submissive to the other player's requests. More specifically but not by way of limitation, during the second round of play the players not wearing the hat 200 utilize the second deck of cards 120 to determine which of the players not wearing the hat 200 will require the player wearing the hat 200 to be submissive to the their request ensuing to winning a hand of play during the second round of play of the card game 100 .
The second deck of cards 120 are the rank establishing cards, and are utilized to establish an initial ranking before the first round of play by having each player chose a card from the deck 120 . It is contemplated that each of the cards in deck 120 have either a value or picture such that an established rank from high to low can be established for each of the players prior to the first hand.
It is further contemplated within the scope of the present invention that a board 300 could be utilized to facilitate the playing of the card game 100 . More specifically but not by way of limitation, the board 300 could be utilized to determine the term of the game utilizing the spaces 310 to identify a start and a finish. Additionally, the spaces 310 could have instructions printed thereon for the player wearing the hat 200 to follow during the second round of play.
An example of a preferred embodiment of the present invention will now be described. The object of the game is for each round, each player to get rid of all of their cards, with the rank of each individual determined by the order in which they get rid of their cards. Each player will then move a predetermined number of spaces on the game board base upon their rank. The winner of the game is the first person to move around the board from the start to the finish. The game is played with a standard deck of playing cards, while a rank establishing deck of cards is utilized before the first round to establish each players initial ranking.
The rankings will depend upon the number of players.
For three players, there is the following starting with the highest rank: 1. President; 2. Beer Bitch; and 3. Asshole
For 4 players, there is the following starding with the higest rank: 1. President; 2. Vice President; 3. Beer Bitch; and 4. Asshole.
For 5 players, there is the following starting with the highest rank: 1. President; 2. Vice President; 3. Cabinet Member; 4. Beer Bitch; and 5. Asshole. If there are more than 5 players, the number of Cabinet Members is increased accordingly. If more than 1 Cabinet Members are utilized, each Cabinet Member's Rank is determined by their order of getting rid of their cards.
Although good results have been achieved utilizing a number of players between 3 and 10 (inclusive), it is contemplated to be within the scope of this invention that more than 10 players could play, however a second deck of playing cards may be needed.
The number of spaces each rank is required to move is as follows: President—4 spaces; Vice President—3 spaces; each Cabinet Member—2 spaces; Beer Bitch—1 space; and the Asshole—0 spaces.
The rank of the cards are from highest to lowest, Ace, King, Queen, Jack, 10, 9, 8, 7, 6, 5, 4, 3, with the 2 being a power card, whereby the hand is over, and all the cards are cleared. Good results have also been achieved utilizing the Jokers, and/or the three's as wild cards.
To start the first round, the initial rank of each player will be determined by each player selecting one of the plurality of cards from the rank establishing deck of cards, with each rank represented by a single card. Accordingly, the rank of each player determines the seating order. The President with choose their seat, with the next rank seated to the President's left, with each decreasing rank being seated in a clockwise order there from, such that the lowest rank player, i.e. the Asshole, is sitting the to right of the President.
Additionally, each player, in highest to lowest rank order, gets to choose their particular game piece.
When dealing the cards, the lowest rank player is always the dealer. The dealer will deal to themselves first, and continue dealing in a clockwise manner. Although it is contemplated that the number of cards used can vary, when playing with 3 or 4 players, good results have been achieved by dealing out 9 cards to each player. When playing with 5 or more players, good results have been achieved by dealing out all the cards. When dealing out all the cards, the dealer always takes the last card, regardless of which player would normally be given the card in the normal course of dealing the cards. The dealer is immune from receiving any orders from other players during the dealing process.
In this embodiment, the roles of each of the ranks of players are as follows: The President, can make any other player drink at any time and can make any other player get a beer or other beverage for them. The only exception for the President is when the lowest rank player is dealing, the dealer is immune from request for performance. The President is immune from request for performance from all other players. The President has the option to alter certain rules before each hand dealt. Before the start of each hand, the President can also take the two best cards from the lowest ranked player, and give the lowest rank player any two of the President's cards. The President also starts the first hand of each new round.
The Vice President (VP) can make any other player drink at any time, with the exception of President at all times, and the dealer during dealing. At the start of each hand the VP make take 1 card from the Beer Bitch, and give any card in return. It is further the responsibility of the VP to ensure that the game is progressing in a continuous and smooth manner.
Each of the Cabinet Members can make any lower ranked player, including lower ranked Cabinet Members, drink at any time, with the exception of the dealer during dealing.
The Beer Bitch, can only make the lowest rank player, i.e. the Asshole, drink, but has the responsibility to serve all other players their beers when needed.
The lowest ranked player, i.e. the Asshole, is in charge of dealing the cards each hand, and retrieving all cards played in each hand. The Asshole cannot make any other player drink, and must perform per any players request, with the exception of when dealing the card.
To play the game, as described above, before each round, the President can pick and choose certain rules to be in effect for that particular round. These rules are described herein below. Once the card are dealt, the Asshole must give their two best cards to the President in exchange for two cards from the President. The Beer Bitch must also give their single best card to the VP in exchange for a single card from the VP. If during play, either the Beer Bitch or the Asshole are caught by other having not given their highest card(s) accordingly, they are automatically the Asshole for the next round of play.
Before each hand starts, a toast should made by player to the President. If no toast is offered, the President can hand out a “punishment” of their liking.
For the start of the first hand of the round, the President will play the first card of the hand. Once the first card is played, the order of play is the descending rank of the remaining players. For example, the VP will play the second card. Each player's turn have the option to play a higher card that the previous card, or a matching card. If a higher card is played, the play continues on to the next player. If the card matches the previous card, the next player is skipped, and that player must drink. If the current player does not have a higher card than the most recent played card, that player does not get to play a card, i.e. that player passes, however that player must drink. A hand ends when any player throws a “2” card, or when all players pass. The last person to play a card starts the next hand. During the hands, the rank order for the next round is established by the order the players get ride of all their cards. Once a player gets rid of all of their cards, they are finished for the round. The Asshole for the next round, is the last player to have cards remaining. When the round ends, the rankings for the next round have been established, and each player moves their piece around the board the number of spaces corresponding to their new rank.
The game is finished when the first player successfully traverses the game board from start to finish.
An example of rules that are selectable by the President before each round include but are not limited to: doubles on singles—where any two cards of the same value, i.e. a pair, beats any single card played; 3's and/or Jokers are wild—can be used as any card, except a 2 card, and when played the value of the wild card must be given by the player; Card Giveaway—when a player's hand contains only 2s and wild cards, on the next turn of that player, they my give all remaining cards away at once, and go out; Jumping Socials—occur when three of the same card are played consecutively, any player (in or out of turn) my play the fourth card of that, whereby all players must drink i.e. a social drink, and the hand finishes, whereby all cards are cleared and a new hand started; The 69 Rule—a player holding a 6 and a 9 card can play both cards at the same time, having the result of completing the hand, with the 6 and 9 combination being playable on anything; and Last Card Rule—whenever a player is down to their last card, they must call out “Last Card” prior to the next player playing their card, else, if another player identifies that “Last Card” has not been called out, the player with one card is either give another card, or made Asshole for the next round.
It is further contemplated that the present invention not be limited to a drinking gamer, rather could also be played as a “strip” game, whereby players are required to strip off articles of clothing rather that drink. Good results have been achieved playing a strip version as follows:
Before playing strip asshole you must first choose the clothing stakes for each round of play. As not everyone is willing to get totally naked, a vote can be taken to determine how much removal of clothing is required to end of the game. The totally nude version consists of every player only having 3 articles of clothing to remove therefore the ladies must remove their bras and panties together as last article to make it fair for the guys considering most men do not wear such clothing. The President will choose the version or rules of the game after drawing the “who da asshole” cards. The President may choose from the versions listed below
The version of the game may be played in 5 different ways, with the playing of the actual game similar to the drinking version.
1. At the end of each round the asshole is the only player to remove one article of clothing. 2. At the end pf each round the asshole and the beer bitch are the only two players to remove one article of clothing. 3. At the end of each round the asshole removes two articles of clothing and the beer bitch removes one. 4. At the end of each round every player except the President and the vice president lose one article of clothing. 5. At the end of each round every player but the President loses one article of clothing and the Asshole loses two.
In the preceding detailed description, reference has been made to the accompanying drawing that form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments, and certain variants thereof, have been described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that other suitable embodiments may be utilized and that logical changes may be made without departing from the spirit or scope of the invention. The description may omit certain information known to those skilled in the art. The preceding detailed description is, therefore, not intended to be limited to the specific forms set forth herein, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents, as can be reasonably included within the spirit and scope of the appended claims.
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A card game that includes a first deck and a second deck of standard playing cards, a hat and a game board to facilitate playing of the card game. The first deck includes a complete set of fifty two standard playing cards and are utilized to facilitate a first round of play comprising of a plurality hand. The second deck is a rank establishing deck and is utilized to establish each players rank prior to the initial round of play. A hat is worn by a player subsequent to the first round of play functioning to identify the loser of the first round. A game board is further included to control the term of the game.
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FIELD OF THE INVENTION
This invention relates to a deburring apparatus which enhances the accuracy, versatility and the availability of deburring operations for deburring the inside edges of drilled holes cut in tubes or machined parts.
BACKGROUND OF THE INVENTION
In many manufacturing operations, metal articles are cut or machined in a manner which leaves a burr. Removal of these burrs, referred to as deburring, has become an important step in the overall manufacturing process. A manufactured article will not be considered good quality, and in most cases not even of acceptable quality, unless it is free of burrs. This is particularly true as quality standards increase. Thus, for many machined articles it is essential to achieve uniform and accurate deburring.
For some parts, deburring may be performed manually at a grinding station, using a grinding wheel. However, this method is not suitable for parts which are machined in such a way that there is no easy access to the burr. For instance, a tube which has one or more holes cut therein and oriented perpendicular to the tube axis will almost always have a burr along the inside edge, adjacent the holes.
To remove burrs of this type, it is necessary to extend some type of cutting tool into the end of the tube, with the distance of extension depending upon the distance of the hole from the end of the tube. The greater this distance, the more difficult the deburring operation. Also, if the tube has a relatively small inner diameter, this deburring operation becomes even more difficult.
While it is known to utilize machines of various type to perform operations such as cutting, champferring, grinding, machining, etc. at the ends of tubes, generally machines of this type are relatively complex, expensive and particularly suited to only one type of machining operation. Thus, such machines are not readily suited for the seemingly simple operation of removing burrs located inside of a tube, especially when such burrs must be removed from tubes of varying sizes and shapes, and with differently shaped holes.
Applicant developed a deburring piece which, in conjunction with a standard drill press, has proved suitable for deburring the inner edge of a hole accessible only via the inside surface of a tube. This deburring piece mounts to the vertical chuck of the drill press and has a midsection which extends horizontally in cantilever fashion from the axis of the drill. A vertically oriented countersink located at the outer end of the midsection is rotatably driven about a vertical axis via operation of the drill press. The rotation of the drill is coupled to the countersink via gears housed in the midsection. By manually extending a tube around the midsection in the proper orientation, with the tube oriented horizontal, the rotating countersink may be used to remove any burrs located along the inside surface of the tube, particularly burrs surrounding the inner edges of holes.
This manner of deburring tubes requires the use of the drill press, thus occupying a relatively cumbersome and awkward piece of machinery with an operation for which it has not been specifically designed. Also, to change over from deburring to drilling operations, and vice versa, additional manufacturing time is lost. As a result, when using a drill press for deburring, the seemingly simple operation of deburring has a disproportionately high cost.
With respect to the actual deburring step, because of the cantilevered orientation of the midsection with respect to the vertical drill, the midsection may sag downwardly to some degree at its outer end, particularly if the midsection is relatively long and extends a substantial distance into the tube. This sag adversely affects the gear drive, which may result in inconsistent or poor quality burr removal from the inside of the tube. Thus, to some degree, the distance of the hole to be deburred from the end of the tube dictates the overall consistency of burr removal.
Finally, in the past, internal deburring has generally not been regarded as a manufacturing operation which merits separate machinery, or a separate dedicated work station. Rather, deburring has been regarded as an ancillary operation.
SUMMARY OF THE INVENTION
It is an object of this invention to reduce the costs associated with deburring the inside surface of a tube.
It is another object of the invention to enhance uniformity in burr removal from the inside surfaces of tubes, particularly along the inner edges of holes cut in the tubes, regardless of the distance of the holes from the end of the tubes.
It is still another object of the invention to enhance overall versatility in removing burrs from the inside surfaces of tubes, at minimal cost.
This invention achieves the above-stated objects by utilizing a stand-alone deburring apparatus with a horizontally oriented countersink to remove burrs from the inside of a tube held in vertical orientation, and while supported on a horizontal support surface of a collar surrounding the body. Because this deburring apparatus is designed to be used as a stand-alone device, used only for deburring, there is no need to tie up a drill press for deburring operations. No time is lost changing over between drilling and deburring, and vice versa. This results in a cost savings, compared to performing deburring operations with a drill press.
Because the countersink is oriented horizontally so as to rotate about a horizontal axis, and mounted to a vertically oriented body which houses a gear drive, the tube may be oriented vertically in axial alignment with the body during burr removal. With the collar being vertically adjustable with respect to the countersink, the apparatus can be readily adapted to accommodate deburring of holes located various distances from the end of the tube. Because the body is oriented vertically and not susceptible to sagging, this invention also promotes consistency in the removal of burrs located inside of tubes.
According to a first preferred embodiment of the invention, a stand-alone deburring apparatus includes a base plate, a motor, a horizontal shaft rotatably driven by the motor and a body mounted vertically adjacent an end of the shaft. The body is recessed in a block mounted to the base plate. The body houses a plurality of intermeshed, toothed gears, with a lowermost of the gears coacting with the shaft to be rotatably driven thereby, and to also drive the rest of the gears. An uppermost of the gears coacts with an inner portion of a horizontally oriented countersink mounted adjacent the top of the body, thereby to rotate the countersink about its longitudinal, horizontal axis upon rotation of the shaft. The countersink also includes an outer portion machined for deburring during right-handed rotation.
A collar surrounds the body and is vertically adjustable with respect to the countersink, as by threaded engagement with the body. The collar has a top support surface for supporting a tube in vertical orientation, in axial alignment with the body during deburring.
According to a second preferred embodiment of the invention, a collar section surrounds the body and is supported at a selectable distance above the block via at least two posts.
A control panel for controlling operation of the motor may be mounted to a second plate hingedly connected to the base plate. This facilitates operation of the apparatus in a convenient manner. Also, a light housing adapted to receive a light may be mounted to the motor or the plate, via a flexible conduit, thereby to direct light in a manner desired to facilitate viewing by the operator during burr removal.
By using interchangeable bodies of varying dimension and/or varying diameters for the countersink, this stand-alone deburring apparatus may be used to deburr tubes having substantial variation in inner diameter, hole diameter and hold distance to the end of the tube.
These and other features of the invention will be more readily understood in view of the following detailed description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a stand-alone deburring apparatus constructed in accordance with a first preferred embodiment of the invention.
FIG. 2 is a side view of a stand-alone deburring apparatus constructed in accordance with the invention, with some variation from the apparatus shown in FIG. 1.
FIG. 3 is a longitudinal cross sectional view of the plate, the body, the collar and the countersink of the stand-alone deburring apparatus shown in FIGS. 1 and 2, during deburring of the inside surface of a tube.
FIG. 4 is a cross sectional view taken along lines 4--4 of FIG. 3.
FIG. 5 is a perspective view of a portion of a stand-alone deburring apparatus constructed in accordance with a second preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view of a stand-alone deburring apparatus 10 constructed in accordance with a first preferred embodiment of the invention. The apparatus 10 includes a base plate 12 which is of suitable dimension and sturdiness to support the other components of the apparatus 10. If desired, the base plate 12 may be permanently or temporarily mounted to the surface of a table, or supplied with supports or legs.
The base plate 12 supports a motor 14. Preferably, the motor 14 is a variable speed d.c. motor. The motor 14 is held to the base plate 12 on opposite sides by braces 16, which are secured by bolts 18. Electrical controls for operating the motor 14 are preferably mounted to a freestanding control panel 20, which is spatially removed from the motor 14, but connected thereto via electrical conductors (not shown) extended through a flexible conduit 22. As shown in FIG. 1, the control panel 20 includes on/off and speed controls for selective operation of the motor 14. Electrical power for driving the motor 14 is supplied via a conventional electrical line (not shown) connectable into an electrical outlet (not shown) supplying 110 volts a.c. If desired, a light housing 24 may be used to support a light (not shown) therein, thereby to facilitate viewing of burring operations, with the light housing 24 operatively connected to the motor 14 via a flexible conduit 26 through which electrical conductors (not shown) extend.
The motor 14, or more particularly the motor housing has an end wall 26 which converges to a hub shape 30. A shaft 32 of the motor 14 extends through the hub, as best shown in FIG. 2. A block 34 mounts to the base plate, preferably by bolts 36. A body 38 also mounts to the base plate 12. The body 38 is actually an elongated member mounted to the base plate 12 in vertical orientation, and partially recessed within the block 34. Structurally, the body 38 and its attendant structural components are practically identical to the deburring piece formerly used by applicant in conjunction with a drill press, as described in the background section of this application.
A collar 40 surrounds the body 38, and the collar 40 is preferably vertically movable with respect to the body 38 via intermeshed internal threads (not shown) sized to cooperate with external threads 42 of the body 38. According to this construction, it is preferable to use an O-ring (not shown) between the body 38 and the collar 40 to prevent metal filings from wedging between the body 38 and the collar 40 and destroying the threads. A countersink 44 mounts adjacent an upper end of the body 38, and the countersink 44 is oriented horizontally and adapted to rotate about its horizontal axis.
FIG. 2 shows a variation of the stand-alone deburring apparatus 10 shown in FIG. 1. Primarily, FIG. 2 shows a second plate 46 hingedly connected to the base plate 12. According to this variation, the control panel 20 mounts to the second plate 46, and because second plate 46 is hingable, the control panel 20 may be located at a desired angle with respect to the base plate 12 to facilitate manipulation of the controls.
FIG. 2 also shows in greater detail the orientation of the shaft 32 with respect to the collar 40, the body 38 and the countersink 44. More specifically, collar 40 is located between the shaft 32 and the countersink 44.
FIG. 3 shows these structural components in even greater detail. More particularly, FIG. 3 shows the block 34 secured to base plate 12 via a bolt 48 extending vertically through a bottom of the block 34 and threadably secured to a bottom end of the body 38. The shaft 32 extends through an opening 49 in the body 38 so as to coact with a lowermost gear 50 of a plurality of gears housed within the body 38. The lowermost gear 50 is rotatably driven about a horizontal axis via rotation of the shaft 32. This in turn drives all of the other gears, including an uppermost gear 52 which coacts with the countersink 44 to rotate the countersink 44 about its longitudinal, horizontal axis. The body 38 also houses an odd number of intermediate gears 54 located between the lowermost gear 50 and the uppermost gear 52.
Preferably, there is an odd number of intermediate gears 54, thereby to provide an odd number of gears in total, counting the lowermost gear 50 and the uppermost gear 52. This assures that the countersink 44 is always rotatably driven in a right-handed manner, the direction for which it has been machined for cutting purposes. Preferably, all of the gears are toothed gears and mounted in intermeshed relationship. The teeth of at least one of the gears are adapted to shear upon application of a force equal to or greater than a predetermined magnitude. This shearing decouples the shaft 32 from the countersink 44, a result which is preferable to stalling or possibly damaging the motor 14 via a sudden stopping of the shaft 32, as may occur if the countersink 44 is placed in engagement with an immovable surface.
FIG. 3 also shows in greater detail the separate components of the body 38. More particularly, body 38 includes a lower portion or yoke 56, an upper end of which extends vertically inside an upper portion, or shell 58. The outer surfaces of the yoke portion 56 and the shell portion 58 define the opening 49 through which the shaft 32 extends. Also, the gears 50, 52 and 54 are held in place via machined axles 59 which are received within horizontal openings 60 in the yoke 56, and the shell portion 58 confines the axles 59 within these horizontal openings 60.
At an upper end of the body 38, an end piece 61 is secured thereto via a bolt 62. FIG. 3 also shows the bottom end of a tube 64 located in a position such that the countersink 44 engages the inside edge of a perpendicular hole 66 machined through the tube 64. Reference numeral 68 indicates the vertical distance between the bottom of the hole 66 and an upper support surface 70 of the collar 40. Preferably, prior to deburring, the collar 40 is rotatably moved to a position with respect to the countersink 44 such that the countersink 44 is vertically centered within the hole 66. This maximizes the effectiveness of deburring along the inside surface of the tube 64, around the inner edge of the hole 66. If this centering dimension 68 changes for a different tube 64, collar 40 is vertically adjusted, as necessary.
FIG. 4 shows in greater detail the mounting of countersink 44 to body 38, and particularly the uppermost gear 52. More particularly, the countersink 44 includes an inner portion 72 received within an inside diameter of the uppermost gear 52 in an interference fit, so that rotation of the uppermost gear 52 also rotatably drives the countersink 44, and in the same direction. The countersink 44 also includes a machined outer portion 74, which as mentioned above, is machined to deburr most effectively during right-handed rotation.
FIG. 5 shows the relevant portions of a stand-alone deburring apparatus 10 constructed in accordance with a second preferred embodiment of the invention. In this embodiment, the structural components for locating the support surface 70 with respect to the countersink 44 are somewhat different, but the principles are the same. The block 34 is again mounted to base plate 12. A collar section 78 surrounds the body 38, and the collar section 78 includes a top 80 and a bottom 82. Two posts 84 are embedded or received within recesses (not shown) formed in the block 34, on opposite sides of the body 38. The collar section 78 includes openings sized to receive the posts 84.
A knurled knob 86 connects to a threaded member 88 which is threadably received in horizontal orientation into the bottom 82 of the collar section 78. By positioning the collar section 78 at a desired vertical position with respect to the countersink 44, and then tightening knob 86 until an innermost end thereof resides in frictional engagement with the posts 84 (on both sides of block 76), the support surface 70 may be set at the desired vertical position.
Once the collar section 78 is set in its desired vertical position, deburring operations are the same as described above for the apparatus 10 shown in the other drawings.
With a variable speed motor 14 having a 0.5 horsepower, this stand-alone deburring apparatus 10 can be used to produce clean and precision deburring in seconds for holes 66 having a diameter ranging from 1/16" to 3/4". Using a motor 14 with greater horsepower will allow a further increase in the diameter of holes 66 to be deburred. The apparatus 10 may also be used to deburr tubes 64 having an inner diameter ranging from 3/8" to 12". Finally, the body 38 is sized in vertical dimension to accommodate distances 68 ranging from zero to 18" or even higher, if necessary. To further accommodate deburring operations beyond the dimensions recited herein, the body 38 and its attendant structural components may be sized as desired, and a bottom end of these other bodies 38 constructed so as to be interchangeable to fit within the block 34.
In operation, a human operator first selects a body 38 and a corresponding countersink 44 which are suitably sized for the inner diameter of the tube 64 to be deburred, with the body 38 being of sufficient length to accommodate the distance 68 between the end of the tube 64 and the hole 66 around the edges of which the burrs are located. This step will not be necessary in many cases.
The collar 40 or collar section 78 is located in a desired vertical position with respect to the countersink 44. The tube 64 is then manually supported on the support surface 70, and the motor 14 is actuated to rotatably drive the shaft 32, the lowermost gear 50, the uppermost gear 52 and the countersink 44. The tube 64 is manipulated by the operator to effectively deburr the inner edges of one or more holes 66 located adjacent an end of the tube 64. With that accomplished, the other end of the tube 64 may be deburred in like fashion, or if the holes are located at only one end of the tubes, another tube may be deburred.
In this manner, this stand-alone deburring apparatus 10 provides consistent, high quality burr removal from the inside edges of holes 66 spaced from the ends of tubes 64. Moreover, because this apparatus 10 is designed to perform deburring as a separate, stand-alone operation, it eliminates the need to occupy a drill press, thus reducing the overall cost of deburring operations.
Moreover, because the body is oriented vertically and the countersink rotates about a horizontal axis, the apparatus 10 provides a continuous and consistent drive force for the countersink 44, regardless of the distance 68. Stated another way, the apparatus 10 is not susceptible to the sag which adversely affected the drive mechanism of the prior deburring piece used in conjunction with a drill press.
While two preferred embodiments of the invention are illustrated and described in considerable detail, it is not the intention of applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will be readily apparent to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's general inventive concept.
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A stand-alone deburring apparatus greatly facilitates accurate deburring of difficult-to-access burrs located inside tubes, and does so in a manner which eliminates the need to tie up another more cumbersome and costly piece of machinery, such as a drill press. The apparatus includes a base plate, a motor with a horizontal shaft mounted to the base plate and a deburring body mounted vertically, adjacent the end of the shaft. The shaft coacts with toothed gears inside the body to rotatably drive the gears and a horizontally-oriented countersink coupled thereto. An adjustable collar provides a support surface or platform for supporting a tube to be deburred in alignment with the axis of the vertical body. With the vertically-oriented body, the horizontally-oriented countersink and the adjustable collar, the inside of a tube may be easily deburred while held in vertical orientation. This invention enhances the accuracy, the versatility and the availability of deburring operations for deburring the insides of tubes, for a relatively wide range of tube diameters and burr locations.
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BACKGROUND OF THE INVENTION
The present invention is a process for the preparation of tricyclo-[3.3.1.1 3 ,7 ]dec-2-yl- [R-(R*,R*)]-3-(1H-indol-3-ylmethyl)-3-methyl-4,9-dioxo-7,11-diphenyl-10-oxa-2,5,8-triazaundecanate of the formula: ##STR1##
This compound is a key compound in the preparation of a new class of highly selective and orally effective gastrin and CCK-B antagonists (see D. C. Horwell et al, J. Med. Chem., 1991;34:404-14. The compounds, their preparation, methods of using them, and compositions containing them are found in U.S. Ser. No. 07/629,809, filed Dec. 12, 1990 hereby incorporated by reference. The final products are useful as pharmaceutical agents in the treatment of anxiety, appetite disorders, excess gastric acid secretion, gastrointestinal ulcers, psychoses reaction caused by drug or alcohol withdrawal, cocaine, benzodiazepine, or nicotine withdrawal to potentiate the effects of morphine, pain, and depression for cognition.
It is an object of the present invention to provide an economical process, which can be carried out on a technical scale, for the preparation of this compound with a high degree of purity.
DETAILED DESCRIPTION
In Scheme 1 below, the carbodiimide method uses 1-hydroxybenztriazole hydrate as catalyst, starting from an optically-active, mono-protected diamine of Formula (II), with the also optically-active R-α-methyltryptophane derivative of Formula (III). The mono-protected diamine (II) is prepared starting from R-(-)-α-phenylglycinol via N-[(benzyloxy)carbonyl]-(R)-β-amino-2-phenylethanol (IV) and N-[(benzyloxy)carbonyl]-0-(toluene-4-sulphonyl)-(R)-β-amino-2-phenylethanol (V).The last-mentioned tosyl compound (V) is reacted with sodium azide in dimethylformamide to give N-[(benzyloxy)-carbonyl]-(R)-β-amino-1-azido-2-phenylethane (VI) which is subsequently hydrogenated to give the mono-protected diamine N B -[(benzyloxy)carbonyl]-(R)-β-amino-2-phenylethylamine (II). ##STR2##
The process of the instant invention is preferred over the known process (see D. C. Horwell et al, J. Med. Chem., 1991;34:404-14), as the reaction of the tosyl compound of Formula (V) with sodium azide, a crude azide results which, besides the desired compound of Formula (II), also contains up to 5% of benzylazide which cannot be removed at this stage because of the potential instability of azides. Consequently, in the subsequent hydrogenation of the azide mixture, a crude amine mixture results which, besides the desired amine of Formula (II), also contains, inter alia, benzylamine. This benzylamine cannot be separated off without great effort and, in the subsequent coupling with the R-β-methyltryptophane derivative of Formula (III), reacts analogously to the amine (II). The resulting impurity of Formula (VII) can only be separated by a laborious column chromatographic purification, which must often be carried out several times. Since the N-β-[(benzyloxy)-carbonyl]-(R)-β-amino-2-phenylethylamine of Formula (II) is obtained as an oily crude mixture, the precise amount of the desired product can only be ascertained with difficulty. The subsequent coupling reaction uses it in an approximately 45% excess. The reaction mixture obtained must be purified by an extremely laborious and time-consuming column chromatographic separation in order to obtain an end product (I) which is sufficiently pure for further reactions. Furthermore, N-β-[(benzyloxy)-carbonyl]-(R)-β-amino-2-phenylethylamine (II) proves to be storage-unstable since this amine absorbs carbon dioxide from the air and is thereby partly converted into a carbonate which is insoluble in the solvents used for the coupling.
Surprisingly, we have now found that the amine (II) forms a stable, sparingly soluble, nonhygroscopic stoichiometric salt (VIII) with carbonic acid when the crude azide, without any further purification, is hydrogenated in ethyl acetate in the presence of a catalyst, for example, Raney nickel. A small amount of alcohol is added to the clearly filtered solution and subsequently gaseous carbon dioxide is passed in or solid carbon dioxide is added. See Scheme 2 below. ##STR3##
The carbonate (VIII) thereby precipitating out selectively and almost quantitatively with an absolute purity of >98%, benzylamine remaining behind in the mother liquor as impurity.
Furthermore, we have, surprisingly, found that the carbonate salt of the amine (VIII) can be directly reacted in stoichiometric amount, i.e., without liberation of the amine (II), with the R-α-methyltryptophane derivative (III) to give the title Compound (I) in Scheme 3 below. ##STR4##
In the above process, the title Compound (I) is obtained in almost quantitative yield and, without column chromatographic purification, with a purity of about 98% and can be used directly for the further synthesis of various active materials.
The following Examples are given for the purpose of illustrating the present invention.
EXAMPLE 1
N.sup.β -[(Benzyloxy)-carbonyl]-(R)-β-amino-2-phenylethaneamine carbonate
22.7 g N-[(Benzyloxy)-carbonyl]-(R)-β-amino-1-azido-2-phenylethane were dissolved in 300 mL ethyl acetate and hydrogenated for 15-hours at 25° C. and at a pressure of 80 ats in the presence of 7.3 g Raney nickel (B 113 W, Degussa). The hydrogenation solution was filtered clear and subsequently mixed with 90 mL ethanol. Gaseous carbon dioxide was passed into this solution, causing a white product to precipitate out. The filter cake was washed with a little ethyl acetate/ethanol (10:3 v/v). The product was dried at 40° C. in a circulating air cabinet. The yield of N.sup.β -[(benzyloxy)-carbonyl]-(R)-β-amino-2-phenylethylamine carbonate was 18.5 g (79.5% of theory); mp 136.3° C.; [α] D =-34.1° C. (c=1/methanol).
EXAMPLE 2
Tricyclo-[3.3.1.1 3 ,7 ]dec-2-yl-[R-(R*,R*)]-3-(1H-indol-3-ylmethyl)-3-methyl-4,9-dioxo-7,11-diphenyl-10-oxa-2,5,8-triazaundecanate
4.08 g N-[(2-Adamantyloxy)-carbonyl]-α-ethyl-R-tryptophane were dissolved in 25 mL ethyl acetate and mixed at 20° C. with 1.53 g 1-hydroxy-1H-benztriazole hydrate and 2.06 g dicyclohexylcarbodiimide. After stirring for 2 hours at 20° C., precipitated dicylohexylurea (2.12 g=94.6% of theory) was filtered off. 3.01 g N- B -[(benzyloxy)-carbonyl]-(R)-β-amino-2 -phenylethylamine carbonate was added, while stirring, to the clear filtrate over the course of about 15 minutes, the carbonate going into solution with the formation of carbon dioxide. The reaction mixture was stirred for 16 hours. After filtering clear, 25 mL ethyl acetate were added thereto. The solution was washed 3 times with 150 mL 5% citric acid solution, 2 times with 150 mL 5% sodium hydrogen carbonate solution, and subsequently with 25 mL water. If an emulsion is formed, it can be broken by the addition of sodium chloride. The organic phase was dried over anhydrous sodium sulphate and filtered. After evaporation on a rotary evaporator, a foamy product remained behind (6.05 g=93% of theory; HPLC: 98.89 relative %) .
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The present invention provides a process for the preparation of tricyclo- [3.3.1.1 3 ,7 ]dec-2-yl-[R-(R*,R*)]-3-(1H-indol-3-ylmethyl)-3-methyl-4,9-dioxo-7,11-diphenyl-10-oxa-2,5,8-triazaundecanate, an important compound in the preparation of a new class of cholecystokinin inhibitors, wherein N-[(benzyloxy)carbonyl]-(R)-β-amino-1-azido-2-phenylethane is hydrogenated, and subsequently, by means of carbon dioxide, the resulting N.sup.β -[(benzyloxy)-carbonyl]-(R)-β-amino-2-phenylethylamine carbonate is precipitated out. This is coupled by the carbodiimide process with N-[(2-adamantyloxy)-carbonyl]-α-methyl-R-tryptophane.
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BACKGROUND OF INVENTION
This invention relates to improved sawmill methods and apparatus, and more particularly relates to improved methods and apparatus for cross-cutting the ends from sawlog slices to produce lumber, railroad ties and the like, cut to a predetermined length. More specifically, this invention further relates to a self-contained trimmer section for a fully automated sawmill.
It is well known that trees are grown and harvested to produce sawlogs, and it is also well known that these sawlogs are carried to sawmills where they are sliced into boards, timbers, railroad ties, and other forms of wood stock. In Applicants' U.S. Pat. No. 3,943,808, which issued Mar. 16, 1976, there is described and depicted a complete sawmill incorporating certain novel concepts including, but not limited to, a modular-type construction wherein each section of the mill is constructed so as to be structurally and functionally independent of the other sections, but wherein such sections can be quickly and easily joined together to produce a functionally integrated sawmill. As will hereinafter be explained in detail, a sawmill of this type is not only cheaper and easier to erect, it can also be disassembled and then re-erected at a different location. In addition, however, the operation of these sections can be easily integrated whereby automation of such a sawmill can be achieved.
Referring more particularly to the modular sawmill described in the aforementioned U.S. Pat. No. 3,943,808, it may be seen that a unique feature is a platform which is constructed of a plurality of scheduled piers, longerons and other prefabricated pieces to provide a unitary supporting structure having three functional levels. Thus, the modular sawmill may, after the platform has been erected, be assembled merely by depositing and by thereafter connecting the various sections together by means of appropriate electrical cables and pneumatic conduits, whereby the various sections are transformed into an integrated operating assembly as hereinbefore stated.
As also previously stated, since the various component sections of the mill are structurally independent of each other, they can be prefabricated and only thereafter carried to the millsite. Accordingly, most of the time required to erect such a sawmill will be spent in building the platform, since only a minimal period is required to position the modules or sections onto the platform and to thereafter cable them together into a functional unit.
As is more fully set forth in the aforementioned U.S. Pat. No. 3,943,808, the trimmer section of a sawmill conventionally performs its function intermediate of the originally slicing function and the disposition of the fully cut pieces to a location where they are held for loading onto trucks and the like. In an automated sawmill, therefore, the trimmer section performs an intermediate function which must be fully coordinated with functions performed both prior and subsequent thereto.
In accordance with the principles set forth for achieving the advantages of the modular concept, a trimmer section is hereinafter provided which automatically receives timbers and other partially cut pieces carried thereto, arranges and conducts such pieces to a location immediately preceding the trimming saws, selects and conducts each such piece individually to the trimming saws, cuts such pieces to a predetermined length or lengths, and thereafter discharges such trimmed pieces to other handling equipment which then transports them to one of a preselected holding locations.
In further consistency with the principles of a modular sawmill, the trimmer section incorporating the concepts of the present invention is structurally independent of the other sections of the sawmill, and is also adapted to be installed on the aforementioned platform for compatability with such other sections. On the other hand, and in further consistency with the aforementioned principles of the modular-type sawmill, the trimmer section embodying the present invention may either be operated independently of the other sections of the sawmill, or it may be functionally integrated with such components to produce a sawmill which is automated to a high degree.
PREFERRED EMBODIMENT
In a preferred embodiment of the present invention, a trimmer deck assembly is provided which is adapted to be disposed on a platform of a modular-type sawmill at a right angle to a roller bed assembly leading from the slicing saw. A pair of drag-off arms are disposed at the receiving end of the trimmer deck, for extension across the first roller bed section, and are further responsive to actuation of a stop assembly in such roller bed section. Accordingly, whenever a sawlog slice travels longitudinally down the roller bed section to impact against the stop assembly, the two drag-off arms are then energized by the stop assembly to laterally shift the slice from the roller bed section onto and across the chains of the trimmer deck.
Each time a sawlog slice is shifted onto the receiving end of the trimmer deck, it tends to abut and shift one or more prior slices laterally along the chains a distance corresponding to the width of the last received slice. Accordingly, one of such slices will eventually be shifted onto a pad-type actuating switch which, when depressed by the weight of such slice, actuates a motor to travel the chains to carry all slices then on the deck towards its opposite end. Eventually, therefore, the trimmer deck becomes a repository for a plurality of sawlog slices each extending laterally across the deck and resting on the movable chains running along its edges.
The slices will usually be rectangular in cross section, rather than square, and for reasons which will hereinafter be apparent, it is desirable that the slices not stand on end on the trimmer deck. Accordingly, a pendulum-actuated switch is disposed over the trimmer deck, at a height whereby it will only be actuated by a slice which is then standing on end. When this happens, however, a flipper mechanism is energized which, striking upward from below the trimmer deck, flips the incorrectly positioned slice over onto its side.
A rotator mechanism, which is located at the discharge end of the trimmer deck, is composed of a pair of notched, semi-circular members mounted on the ends of a rotatable shaft. Thus, the chains of the trimmer deck may be traveled to carry the first received sawlog slice to the opposite end of the deck and into the notches in the two moon members. When such members are thereafter rotated, the sawlog slice inserted therein will then be lifted arcuately over and onto a second pair of arms constructed substantially the same as the aforementioned drag-off arms which, in turn, are actuated to shift the slice forward and onto a third pair of such arms.
It is the purpose of such third pair of drag-off arms to move the slice or timber into position to be cut to a predetermined length by a pair of spaced-apart circular saw blades. The timber must be secured against movement during this step in the operation, however, and thus the timber is preferably drawn by such third pair of drag-off arms laterally into wedging engagement with a pair of uplifted stop members which, when the trimming step has been performed, are operable to shift the trimmed slice or timber onto a second roller bed section leading to whichever storage or collection point has been preselected to receive the timber.
As will hereinafter be explained in detail, the various actuating mechanisms for performing these various steps may be selectively and independently operated as desired, or they may be interconnected and interrelated to function according to a predetermined sequence. It will be readily apparent to those having experience with material handling operations, however, that a large elongate body is such that it may not easily be conducted mechanically from one place to another, especially if it must be transferred both laterally and longitudinally during its course of travel. This is especially true in the case of sawmill operations, since the boards, timbers and other pieces cut from a sawlog are not only relatively massive, but they also will have a variety of different sizes and lengths. Thus, whenever a heavy timber or the like becomes mispositioned along its course of travel, there is an immediately likelihood that succeeding timbers will drive it further awry to create a jam in the operations unless it can be immediately restored to a proper position.
Another problem with operations of this type is that the timbers must not only be shifted both laterally and longitudinally, provision must also be made to shift these pieces rotatably a about their longitudinal axis. As may be seen in the aforementioned U.S. Pat. No. 3,943,808 whenever a piece is sliced off of the sawlog, it tends to fall laterally onto its flat side and onto the first mentioned roller bed assembly or other conveyor section which, in turn, then carries it longitudinally to the receiving end of the trimmer deck assembly. As also hereinbefore stated, the rotator assembly at the discharge end of the trimmer deck, however, picks up and stands each piece on its edge since this is the preferred position for cutting its ends with the two trimming saws. It will be apparent, therefore, that each piece be transferred onto the trimmer deck while lying on its broader side, else the rotator will misposition the piece when it is moved to the trimming saws.
To provide against such a contingency, there is preferably provided a shifting or "flipping" mechanism which automatically examines each piece received onto the trimmer deck and, whenever a piece is found to be standing on its narrower side, rotates or "flips" it over before permitting it to proceed to the rotator. In its preferred form, the flipper will include a serrate or tooth-like member which, upon actuation, rises vertically to catch and lift the lower leading edge of the timber and thereby flip it backward and onto its flat side. The "examining" function may be performed by any convenient device, such as by a beam of light which, when broken by an abnormally tall piece, closes a circuit to the flipper. As will hereinafter be described in detail, however, a particularly suitable examining device is a lever which is danglingly suspended above the trimmer deck and above properly positioned timbers thereon. Whenever an improperly positioned piece strikes and moves this lever, however, it is deflected to close a switch to actuate the flipper.
SUMMARY OF THE INVENTION
In its broader concept, the present invention may be stated to be an improved trimmer section which, in conjunction with the other sections of the sawmill of which it is a part, not only performs its expected function of cutting a board or timber to a preselected length, but which also controls the overall operating sequence of the entire sawmill by selecting the timber to be trimmed and by then routing the trimmed pieces to appropriate receiving points. More particularly, the automated operating sequence may logically be said to begin at the point when a timber has been locked into the trimmer saw section in preparation for trimming. The sawmill operator then initiates the sequence by selecting a particular one of a plurality of different receiving points or locations. When this is done (by actuating the appropriate control), the trimmer saw section will then cut the ends of the timber to provide it with the proper length, and will thereafter transfer the trimmed piece laterally onto a conveyor which, upon receiving the piece, then carries it to and places it on the timber deck designated as the selected receiving location. Coincident with the transfer of the trimmed piece to the conveyor, however, the trimmer saw section also selects and positions the next succeeding untrimmed timber with respect to the trimmer section. This, in turn, allows the trimmer deck to present the next succeeding one of a supply of untrimmed timbers to the trimmer saw section, and also to replenish such supply by taking a replacement piece from the conveyor section extending betwen the main saw section and the trimmer deck assembly. This, in turn, permits this conveyor to conduct another piece to the trimmer deck assembly.
As will hereinafter be explained in detail, the overall trimmer section may be said to have two alternative modes of operation, i.e., the "manual" mode wherein its various operating components may be selectively actuated by the sawmill operator, and the "automatic" mode wherein the components are actuated according to a predetermined sequence as previously described. More particularly, however, the trimmer deck assembly actually has only one "automatic" mode of operation, except that its rotator portion may be selectively controlled and actuated by the operator. Alternatively, it is the trimmer saw assembly which actually has two distinctly different modes of operation. Even then, however, the trimmer saws are manually controlled by the operator in both modes, and the operator must always manually select the storage deck which is to be the destination for each timber moving through the trimmer section.
These and other features and advantages of the present invention will become apparent from the following detailed description, wherein reference is made to the figures in the accompanying drawings.
IN THE DRAWINGS
FIG. 1 is a simplified pictorial representation of an overhead view of one embodiment of the present invention, wherein there may be seen a novel trimmer deck assembly arranged and adapted to receive timbers and the like from a roller bed assembly, and a trimmer saw assembly arranged and adapted to receive such timbers from the deck assembly and, after cutting them to a preselected length, transfer them to a second roller bed assembly.
FIG. 2 is a simplified pictorial view of a portion of the deck assembly depicted in FIG. 1.
FIG. 3 is a simplified pictorial view of another portion of the deck assembly depicted in FIG. 2.
FIG. 4 is a different and more detailed pictorial view of the trimmer saw assembly and portions of the deck assembly depicted in FIG. 1.
FIG. 5 is a simplified view, partly functional and partly pictorial, of different portions of the trimmer saw assembly depicted in FIG. 1.
FIG. 6 is another different view of the functions and mechanisms depicted in FIG. 5.
FIG. 7 is a further simplified pictorial view of a portion of the apparatus depicted in FIGS. 5 and 6.
FIG. 8 is a simplified pictorial view of the details of another portion of the apparatus depicted in FIG. 1.
FIGS. 9 A-C present a simplified schematic diagram of one form of pneumatic circuitry for operating the apparatus depicted in FIGS. 1-8.
FIGS. 10 A-F present a simplified schematic diagram of one form of electro-mechanical circuitry for operating the systems and mechanisms depicted in FIGS. 1-9.
FIGS. 11 A-B present a schematic diagram of the details of selected circuitry depicted more generally in FIG. 10B.
DETAILED DESCRIPTION
Referring now to FIG. 1, there may be seen an overhead view of a first conveyor assembly which extends from a point beside the slicing saw (not depicted) to the receiving end of a trimmer deck assembly as will hereinafter be described. The conveyor assembly may be any suitable device for longitudinally carrying a timber 5 and the like, such as a roller bed assembly 2 composed of a pair of rails 3 having a plurality of revolving rollers 4 mounted therebetween and rotatably driven by a suitable motor (not depicted). As may further be seen, a stop assembly 6 is preferably mounted at a suitable location in the roller bed assembly 2, and a pair of drag-off arm assemblies 8 and 9 are disposed across the roller bed assembly 2 and onto the trimmer deck assembly at its receiving end.
The stop assembly 6 and two drag-off assemblies 8 and 9 are preferably constructed and operated as is more particularly described in the aforementioned U.S. Pat. No. 3,943,808, although other conventional apparatus may be substituted therefor. Accordingly, the stop assembly 6 has an upwardly extending plate 7 which, when impacted by the timber 5, not only arrests the timber 5 across the drag-off arms 8 and 9, closes a switch 108 (see FIG. 10C) to actuate the two drag-off arms 8 and 9 to cause their teeth 10 and 11 to move along the slots 12 and 13 to carry the timber 5 laterally onto the two chains 18 extending along the sides of the deck, and also onto a spring-loaded pad-type switch 14 which, in turn, actuates the deck motor 21.
As may be further seen, the deck motor 21 is connected through an endless belt 23 to a reduction gear 22 which, in turn, is coupled through a sprocket chain 24 to drive shaft 25 which moves the pair of endless chains 18 which ride on the rails 19. Accordingly, the chains 18 will carry the timber away from the roller bed assembly 2 until it clears the switch 14, whereupon the motor 21 will stop until another timber is deposited onto the switch 14 by the two drag-off arms 8 and 9, and whereupon the sequence is repeated.
Referring again to FIG. 1, it will be seen that the trimmer deck illustrated therein extends from the roller bed assembly 2 to the receiving end of a trimmer saw section having its discharge end located adjacent a second roller bed assembly 61 or other suitable conveyor section. Accordingly, the discharge end of the trimmer deck is suitably provided with an unloading mechanism which is preferably a rotator assembly 27 composed of a pair of semi-circular members 29 mounted on a rotatable shaft 28. As will hereafter be explained in detail, whenever a timber is properly moved by the chains 18 into engagement with the two semi-circular members 29, it will depress and actuate a rotator check switch 26 which conditions the rotator assembly 27 for actuation, and which also de-energizes the trimmer deck motor 21.
The rotator assembly 27 may be selectively actuated by the operator. When the system is programmed for automatic operation, however, the rotator assembly 27 will be actuated when the drag-off arms 49 and 50, transfer a trimmed timber or tie onto second roller bed assembly 61. Accordingly, the shaft 28 rotates as hereinbefore stated to deposit the timber carried by the members 29 onto the slotted ends of a pair of loader arms 30 and 31, which may be constructed the same as the drag-off arms 8-9, but preferably having their two tooth members 32-33 reversed so as to push each newly received timber onto and across the slotted ends of the two unloader arms 49 and 50. As will hereinafter be explained, the loader arms 30-31 are actuated by a switch 243 (see FIG. 7) which, in turn, is controlled by the rotator assembly 27.
When the loader arms 30-31 have shifted their tooth members 32-33 to their extended positions in the slots 34-35, the unloader arms 49-50 (which may be constructed the same as the drag-off assemblies 8-9) will be energized to cause their respective tooth members 51-52 to travel along their slots 53-54 for the purpose of carrying the timber laterally into abutting engagement with a pair of upwardly thrustable stop members 55-56. Thereafter, its ends may be severed by the two trimming saws 38-39, which are each revolvably mounted on the ends of a pair of shafts 37 and 37A driven, in turn by two saw motors 42 and 46.
It will frequently happen that a timber will be deposited onto the unloader arms 49-50 so as to extend too far towards one or the other of the two saw blades 38-39. If the timber does not extend to saw 38, the operator will selectively relax the unloader arms 49-50, and actuate the "jog right" mechanism 57 which, in turn, is an upwardly extending claw-like member revolving is a sleeve 59 to engage the lower surface of the timber and shift it toward the saw 38. If the timber does not reach the other saw 39, the "jog left" mechanism 58 may be oppositely revolved in a similar sleeve 60 to shift the timber in the opposite direction.
As may be seen in FIG. 5, the two trimmer saw blades 38-39 are normally positioned below the timber to be trimmed. Referring again to FIG. 1, therefore, it will be seen that the saw blade 38 and shaft 37 is mounted on a pair of arms 40-41 having their opposite ends pivotally and slidably connected along a portion of a long pivot shaft 36. Similarly, the saw blade 39 and shaft 37A is mounted on a second pair of arms 44-45 which, in turn, are also pivotally and slidably amounted on another portion of the long pivot shaft 36. As will hereinafter be explained in detail, means is provided for swinging arms 40-41 and 44-45 upward to bring the saw blades into engagement with the ends of the timber to be trimmed, and to thereafter lower the blades 38-39 after trimming has been accomplished. In addition, suitable means is included for sliding the arms 40-41 and 44-45 along the long pivot shaft 36, whereby the spacing between the saw blades 38-39 may be changed as desired. In addition, either arms 40-41 or arms 44-45 may be separately raised and lowered whereby only one end of the timber may be cut if desired.
The two saw blades 38-39 are selectively raised and lowered by the operator, and they may be raised separately or in combination as may be desired. More particularly, the operator may actuate switch 138 (see FIG. 10B) to elevate the left trimmer saw 39, or switch 139 to elevate the right trimmer saw 38, or switch 140 to elevate both trimmer saws 38-39 simultaneously. Note that switches 138-140 are interconnected in momentary-type circuits, and that they are also spring-loaded open whereby they are merely depressed momentarily to cause the two saws to rise. Thus, when the left saw 39 rises to actuate the left saw up limit switch 142, this will cause the left saw 39 to reverse itself automatically and return to its original position. Similarly, the right saw 38 will continue to rise until it actuates the right saw up limit switch 144 (see also switch 275 and whisker 278 in FIG. 5), whereupon the right saw 38 will return to its original lowered position. If either of switches 138-140 are held closed by the operator, however, then the saws 38-39 will override switches 142 and 144 and continue to rise until their respective actuating cylinders (see cylinder 280 in FIG. 6) reach their limits. At this point, the saws 38-39 can only be retracted by means of switches 141 and 143.
After the saw blades 38-39 have been returned to their original positions below the timber, this will acuate switches 152-153 (see also switch 276 in FIG. 5) which, in turn, conditions the two unloader arms 49-50 to be relaxed, and which also conditions the two stop assemblies 55-56 to be lowered below the timber. When this occurs during the automatic mode, the unloader arms 49-50 will be actuated by switch 271 (see FIG. 6), whereby their two tooth members 51-52 will travel in the slots 53-54 to carry the trimmed timber off of the trimmer saw assembly and onto the second roller assembly 61. If the timber is improperly positioned thereon, the No. 3 flipper assembly 68, which is constructed the same as the No. 1 and 2 flipper assemblies 17 and 75, may be manually actuated by the operator to reposition or re-align the finished timber on the roller bed 61.
As hereinbefore stated, the purpose of the roller bed assembly 61 is to carry the trimmed timber to an appropriate holding location. If the timber is to be transferred onto the No. 1 timber holding deck, this may be effected by merely actuating the two drag-off arms 65-66, whereupon the timber will immediately be shifted onto the arm 67 of a suitable stacker apparatus of the type more particularly described in the aforementioned U.S. Pat. No. 3,943,808. If the timber is scheduled to be moved to the No. 2 timber deck 69, however, then the rollers 63 will be actuated to automatically carry the timber along the roller bed assembly 61 until it impacts against the plate 74 of the stop assembly 73 associated with the No. 2 timber deck 69. This, in turn, actuates the drag-off arms 70-71 to transfer the timber onto the arms 72 of the stacker apparatus associated therewith.
Referring now to FIGS. 2-3, there may be seen a simplified pictorial representation of the structural details of the receiving end of the trimmer deck assembly depicted in FIG. 1. As hereinbefore stated, the various sections of the sawmill are preferably formed to be disposed on a suitable platform which, as indicated in FIGS. 2-3, may be composed of a plurality of vertical piers 76 each having an inverted saddle member 77 mounted on the upper end for supporting a longeron 78 which, in turn, serves to support each of the sections of the sawmill at a preselected location therein. Accordingly, the trimmer deck assembly may be seen to be preferably composed of a plurality of leg members 79 vertically interconnected between a pair of spaced-apart side rails 19 and a pair of long saddle members 80 which, in turn, are adapted to engage the upper surfaces of the longerons 78. In addition, cross members 82 and angle brackets 81 may be included for providing strength to the assembly.
As hereinbefore stated, the two drag-off assemblies 8 and 9 extend from the receiving end of the trimmer deck assembly to and across the transversely adjacent roller bed assembly 2. The operating and structural details of these two components of the system have been fully described and illustrated in the aforementioned U.S. Pat. No. 3,943,808, and therefore an equally detailed description will not now be repeated herein. It should be noted, however, that each such component includes a pneumatically actuated cylinder (not depicted) assembly with a tooth-like member 10-11 pivotally mounted on the free-traveling end of each piston rod (not depicted) therein. Each of the two tooth-like members 10-11 normally project up through one of the slots 12-13 on the opposite side of the roller bed assembly 2 and the timber 5A carried thereon. When the timber 5A impacts against the plate 7 of the stop assembly 6, as hereinbefore explained, the plate 7 actuates a switch 108 (not depicted in FIGS. 1-3) to energize the cylinders (not depicted) in the two drag-off assemblies 8-9. When this occurs, the two tooth members 10-11 will be drawn through the two slots 12-13 to drag the timber 5A off of the roller bed assembly 2 and onto the trimmer deck switch assembly 14. Upon reaching their travel limits, however, a switch (not depicted) located in each drag-off assembly 8-9 is actuated to cause the two cylinders (not depicted) therein to return the two tooth members 10-11 to their original positions.
It should be noted that the two tooth members 10-11 are preferably arranged and adapted to resist arcuate movement in one direction, but to yield to movement in the other direction. Accordingly, the two members 10-11 remain erect only when carrying the timber 5A from the roller bed assembly 2 to the trimmer deck assembly. If the tooth members 10-11 encounter another body upon returning to their original position, they will fold down and ride under it rather than pushing it off of the roller bed assembly 2 in the opposite direction.
As also explained, it is desirable for all timbers to lie on their broader sides when being loaded onto the trimmer deck assembly, as indicated by timber 5A in FIG. 2. If a timber is inadvertently loaded thereon while standing on its narrower edge, however, as illustrated by timber 5B in FIG. 2, means is provided to re-position it.
Referring again to FIGS. 2-3, it will be noted that a side bracket 15 is provided for the purpose of dangling above the trimmer deck assembly means for examining the position of each timber 5A-B carried thereon. More particularly, this examining means may be seen to include a pendulum lever 88, which is adjustably mounted on a plate 89 which, in turn, is pivotally fixed to the end of the side bracket 15. In addition, a knob 90 or other protuberance is provided on the back side of the plate 89 to deflect the whisker 87 of a switch 16, which is also carried by the side bracket 15, whenever the lever 88 hangs in its normal position above the trimmer deck assembly.
As hereinbefore stated, whenever the drag-off arms 8-9 are actuated to remove a timber 5 from the roller bed assembly 2, they will move the timber 5 far enough to actuate the trimmer deck switch assembly 14 which, in turn, may be seen to be composed of a switch 84 having a whisker 85 deflected when the spring-loaded pad assembly 86 is depressed by the weight of the timber 5. This, in turn, actuates the trimmer deck motor 21 to cause the chains 18 to carry the timber 5 further along the trimmer deck assembly until it clears and releases the pad assembly 86, whereupon the motor 21 stops.
It should be noted that each time the pad assembly 86 is depressed by a newly received timber, the chains 18 will not only carry that timber along until it is moved past the pad assembly 86, but they will also carry all preceding timbers along the deck assembly and away from the pad assembly 86. Thus, each timber thereon will be spaced from its adjacent timbers a distance determined by the length of the pad assembly 86, and this provides unimpeded rotation of each timber upon actuation of the No. 1 flipper 17 as will hereinafter be explained.
Movement of the chains 18 will, of course, carry each timber under the dangling pendulum lever 88. The lever 88 is preferably suspended from plate 89 above the trimmer deck assembly a distance such that a timber positioned as shown by timber 5A will not disturb it. When the timber is positioned as shown by timber 5B, however, it will deflect the lever 88 to release the whisker 87 of the switch 16, and this will actuate the No. 1 flipper assembly 17 to overturn the upright timber 5B.
Referring again to FIGS. 2-3, it will be noted that the No. 1 flipper 17 is composed of an engager member having a plurality of rollers 94 located along one edge and on both sides, and further having a jagged or serrate upper end. The rollers are disposed within a vertical channel member 83, whereby the engager member 93 is vertically movable both up and down, but that it is normally disposed below the upper surface of the trimmer deck assembly as indicated in FIGS. 2-3. The switch 16 is a normally-closed device, but it is usually held open by the weight of the lever 88. When the lever 88 is deflected, however, the switch 16 will close to actuate a pneumatic cylinder 91 which, in turn, extends its piston rod 92. The lower end of the engager member 93 is coupled to the free-traveling end of the piston rod 92 by a clevis 95 or the like, and thus extension of the piston rod 92 will drive the upper end of the engager member 93 against the lower leading edge of the upright timber 5B to flip it over and backwards.
Referring now to FIG. 3, it will be noted that when the piston rod 92 becomes fully or substantially fully extended, the whisker 97 will be deflected by one of the rollers 94 or other suitable portion of the engager member 93, to actuate the switch 96. This, in turn, causes the cylinder 91 to retract the piston rod 92 to return the engager member 93 to its original position.
Referring now to FIGS. 5-6, there may be seen a simplified pictorial representation of the discharge end of the trimmer deck assembly. As hereinbefore explained, the endless chains 18 which carry the timbers 5 to the trimming saws 38-39, are moved by a pair of sprocket wheels fixedly mounted at opposite ends of a drive shaft 25 and interconnected with the trimmer deck motor 21 by a sprocket chain 24 and the like. In addition, however, there may be seen a pair of generally semi-circular members 29, which are slidably mounted at the ends of the drive shaft 25 and fixedly interconnected by another shaft 28 to constitute the basic components of the rotator assembly 27 hereinbefore mentioned. More particularly, the two semi-circular members 29 are each provided with a rectangular notch or cut-out portion of a size and shape to receive and accommodate a timber 5C, when it is carried therein by the traveling chain 18, and when they are in their receiving position as depicted in FIG. 6. Thus, when the two semi-circular members 29 are rotated about the drive shaft 25, as will hereinafter be explained, they will arcuately swing over the timber 5C to deposit it across the loader arm assemblies 30-31 as previously stated, whereupon the timber 5C will be in its erect position as indicated in FIG. 5.
As illustrated in FIGS. 5-6, rotation of the two semi-circular members 29 may be effected by the pneumatic cylinder 255 which is anchored between a pair of braces 252 angularly extending to the drive shaft 25, and which has the free traveling end of it piston shaft 256 coupled through a clevis 258 and lever arm 257 to the shaft 28. Actuation of the cylinder 255 may be selectively effected by the operator, as hereinbefore explained, or it may be sequentially effected by the return of the unloader arm assemblies 49-50. On the other hand, the cylinder 255 will not actuate until a timber 5C has depressed the leaf-type actuator 294, to actuate the switch 293, by moving fully into the notches of the semi-circular members 29.
Referring again to FIGS. 4-6, there may also be seen a pictorial representation of certain basic features of the trimmer saw assembly which, in turn, constitutes the other major component of the overall trimmer section of the sawmill. In particular, there may be seen the two loader arms 30-31 which are formed substantially as the two drag-off arms 8-9 hereinbefore described, and which therefore have a pair of tooth-like engaging members 32-33 which extend upwardly therefrom in the slots 34-35, and which are slidably extendable through such slots 34-35 to shove the erect timber 5C forward onto a similar pair of unloader arms 49-50. The loader arms 30-31 are actuated when one of the two semi-circular members 29 reaches full rotation to deflect the whisker 244 of switch 243, as indicated in FIG. 7, but the unloader arms 49-50 are actuated to pick up and shift the timber 5D into abutting engagement with the two upright stop members 265 when the loader arms 30-31 reach their full extension. Thereafter, one or both of the two rotating trimmer saw blades 38-39 may be raised to sever the ends of the timber 5D while it is fixed in this position.
Referring now to FIG. 4, there may be seen another but more detailed pictorial view of the trimmer saw assembly, and more particularly depicting how the right trimmer saw blade 38 is fixed to a circular boss 38A which, in turn, is rotatably mounted between the ends of a pair of arms 40-41 which carry the right trimmer motor 42 on a suitable base plate 259. The left trimmer saw blade 39, in turn, is similarly fixed to a boss 39A which, in turn, is also rotatably mounted between the ends of another pair of arms 44-45 which carry the left trimmer motor 46 on a suitable base plate 260.
Referring again to FIG. 4, it will be noted that the two trimmer saw blades 38-39 are not only independently movable in a vertical direction, but also in a horizontal direction. More particularly, it may be seen that an assembly of two pairs of short and long stroke cylinder assemblies 289-290 are provided for shifting the arms 40-41 and 44-45 along the long pivot shaft 36 according to a plurality of preselected locations each spaced, for example, 6 inches apart. In other words, each of the two short stroke cylinders 289 will have a 6 inch stroke, and each of the two long stroke cylinders 290 will have a 12 inch stroke. Thus, if all cylinders 289-290 are fully retracted, both saw blades 38-39 will be spaced closest together and both will be in "Position No. 1."
If the separation between the trimmer blades 38-39 is to be increased by only 6 inches, this can be effected by actuating only the left short stroke cylinder 289 to shift the left trimmer saw blade 39 to Position No. 2. If the left trimmer saw blade 39 is to be moved to Position No. 3, which is 6 inches from Position No. 2, then the left long stroke cylinder 290 is actuated while the left short stroke cylinder 289 is restored to its original state. If the left trimmer saw blade 39 is to be shifted to Position No. 4, however, then the left short stroke cylinder 289 is again actuated.
It is desirable that the two trimmer saw blades 38-39 be located only at their respective Positions No. 1-4 as hereinbefore explained, and thus a positioning plate or bar 283 is mounted between each of the two pairs of arms 40-41 and 44-45 and is provided with pre-arranged slots or notches 284-287 which, in turn, each accommodate a fixedly and vertically positioned blade 288. Accordingly, if the left trimmer blade 39 is properly located at either Position No. 1-4, its positioning bar 283 will be located so that the proper one of its notches 284-287 will be aligned with its positioning blade 288. If none of the notches 284-287 are exactly aligned with the positioning blade 288, however, the positioning bar 283 will engage the positioning blade 288 to prevent the left trimmer saw blade 39 from being raised.
It will be apparent that it is desirable to provide for adjustment of the saw carriages, however, with respect to the cylinders 289-290. Thus, a suitable adjustment means 291 is preferably included on base plates 259-260, whereby the position of the two arms 40-41 and base plate 258 may be shifted along the long pivot shaft 36, and whereby the position of arms 44-45 and plate 260 may be similarly adjusted. In addition, suitable means may be included for selectively adjusting the position of the short and long stroke pistons 289-290 in increments of one-half inches, relative to the long pivot shaft 36. In this respect, however, it should also be noted that this requires compensating adjustment of the positioning blades 288.
As hereinbefore stated, each of the two trimmer saw blades 38-39 may be raised and lowered independently of the other, and thus each is provided with its own elevating means. Referring now to FIGS. 5-6, it may be seen that the right trimmer saw blade 38 may be moved by means of a fixedly anchored cylinder 280 having the free traveling end of its piston rod 281 slidably and rotatably coupled to its drive shaft 273 by a clevis 282 or the like, and that the saw blade 38 is raised by extension of the piston rod 281. It should further be noted that when the piston rod 281 is fully retracted, the drive shaft 273 (or other suitable part of the assembly) will deflect the whisker 279 to actuate the "right saw down" switch 276, and that the piston rod 281 will become extended only far enough to deflect the whisker 278 of the "right saw up" switch 275. The purpose of the two switches 275-276 is to limit vertical travel of the right trimmer saw blade 38, and thus they are preferably adjustably spaced apart by means of a slotted bracket 277 or the like, as shown in FIG. 5.
The left trimmer saw blade 39 is similarly moved and controlled. However, its limit switches are not depicted in FIGS. 5-6, and only the left saw up switch 275A is shown in FIG. 4.
Referring again to FIG. 4, there may be seen a simplified representation of the No. 2 flipper assembly 75 which, however, is selectively operable by the operator and which is constructed the same as the No. 1 flipper assembly 17 as depicted in FIGS. 1-3. In addition, there may be seen a more detailed representation of both the "jog left" and "jog right" assemblies 57-58, wherein the two bar members are rotatably moved in the sleeves 59-60 by cylinders 261-262.
Referring more particularly to FIG. 6, there may be seen a more detailed illustration of apparatus exemplary of the tie stops 55-56 depicted briefly in FIG. 1 and in FIG. 4, and more particularly relating to the right tie stop assembly 55. In particular, this assembly may be seen to include a stopping member 265 having a plurality of rollers 267 mounted along one edge and on both sides, and which ride in a suitable channel member 268 whereby the stopping member 265 may be raised and lowered to stop or pass the timber 5D then being engaged by the unloader arms 49-50. The right stopping member 265 is further interconnected to the free traveling end of the piston rod 270 of a cylinder assembly 269, and a switch 271 is arranged so that it may be actuated whenever the piston rod 270 is retracted and its whisker 272 is deflected by a roller 267 or other suitable part of the right stopping member 265.
Each of the two tie stop assemblies 55-56 will preferably be raised and lowered together, notwithstanding each is provided with a separate actuating cylinder. Thus, the arrangement depicted in FIG. 8, wherein the left tie stop assembly 56 is lowered independently of the right tie stop assembly 55, is merely to illustrate the relationship of the various components in these two different modes.
Referring now to FIGS. 6 and 8, however, it will be seen that the "jog left" and "jog right" assemblies 57-58, which are more generally illustrated in FIGS. 1 and 4, are operable independently of each other. More particularly, FIG. 8 shows the jog left assembly 58 in its actuated condition for shifting the timber 5D a limited distance toward the left trimmer saw blade 39 (not depicted in FIG. 8), whereby the cylinder 262 has been actuated to rotate the claw-like member in sleeve 60 to pick up and carry over the timber 5D. If it is desired to shift the timber 5D in the opposite direction to the right trimmer saw blade 38, then the "jog left" cylinder 262 will be retracted and the "jog right" cylinder 261 will be actuated to rotate the claw of the job right assembly 57 in the opposite direction.
Referring now to FIGS. 9A-C, there may be seen a simplified functional illustration of the major actuating means for operating the components depicted in FIGS. 1-8 according to the concept of the present invention. In particular, such a system may conveniently include a suitable source 198 of pneumatic pressure which, in turn, is connected to a high pressure line 201. As will be apparent, the system preferably uses both high and low pneumatic pressure, and thus a section of the high pressure line 201 will preferably connect with a suitable pressure regulator 200 which, in turn, is connected through a suitable reservoir 199 to a low pressure line 202.
The operation of the system depicted in FIGS. 9A-C is better understood if considered in sections. More particularly, cylinders 203-204 are the driving means in the drag-off arms 8-9 which travel the tooth members 10-11 depicted in FIG. 1, and thus they are normally extended. Whenever a timber 5 on the first roller bed 2 impacts against the plate 7 of the stop assembly 6, however, switch 108 in FIG. 10C will close to energize both solenoids 161, 163 of the left and right drag-off control valves 160, 162, whereby pressure will be connected from line 201 through ports B-C in both components to retract cylinders 203-204, and whereby ports A-C are connected to provide a return connection. As will also be explained, whenever cylinders 203-204 become fully retracted, however, switches 106-107 will be actuated to de-activate valves 160, 162 and restore them to their original position, whereby the cylinders 203-204 will re-extend.
Cylinder 205 in FIG. 9A corresponds to the cylinder 91 in FIGS. 2-3 which actuates the No. 1 flipper assembly 17, and thus cylinder 205 is normally held in a retracted position by pressure from the reservoir 199 and low pressure line 202. When switch 114 is closed, the No. 1 flipper control valve 164 will reposition to connect ports B and C, and high pressure from line 201 will override the pressure in line 202 to extend cylinder 205. As will hereinafter be explained, switch 114 is preferably momentary in character, but when the No. 1 flipper return switch 115 is closed, the valve 164 will return to its previous position wherein port B is connected to plugged port D, and wherein the return line of cylinder 205 is connected through ports A-C to atmosphere. Accordingly, low pressure in line 202 will again retract cylinder 205.
Cylinder 206 corresponds to the rotator actuating cylinder 255 in FIG. 6, and is similarly normally held retracted by low pressure from line 202. When the two normally open contacts of the rotator check switch 109 are closed (see switch 243 in FIG. 7), however, and when the rotator start switch 117 is also closed, the rotator control valve 166 will reposition to extend cylinder 206, the same as with cylinder 205.
Cylinders 207-208 are the actuating mechanisms for the loader arms 30-31 depicted in FIG. 1, and are operated by the left and right loader arm control valves 168, 170, the same as with cylinders 203-204. Similarly, cylinders 209-210, which actuate the left and right unloader arms 49-50, are operated in the same manner by the left and right unloader control valves 194, 196, except that cylinders 209-210 are normally extended.
Cylinders 211-212 correspond to the two cylinders actuating the tie stop assemblies 55-56 in FIG. 8. As hereinbefore stated, the two tie stop assemblies 55-56 are intended to operate together, and thus both cylinders 211-212 are operated by a single tie stop control valve 184. Note in particular, however, that cylinders 211-212 are normally held extended by pressure from line 201, and that low pressure from line 202 will only retract the cylinders 211-212 when the valve is repositioned to couple port B with C, and port D with A.
Cylinders 213-214 correspond to the cylinders represented by cylinder 280 in FIG. 6, and are connected with valves 180, 182 to operate the same as cylinders 205-206. Cylinders 215-218 correspond to the two pair of short and long stroke cylinders 289-290 depicted in FIG. 4. More particularly, the left short stroke cylinder 215 is extended when valve 172 is positioned to couple ports B and C, and is retracted when the valve 172 is repositioned to couple ports B and D. The left long stroke cylinder 216, in turn, is similarly extended when valve 174 is positioned to couple ports B and C, and is retracted when port B is reconnected with port D in valve 174. Cylinders 217-218 are similarly operated by valves 176,178.
Cylinders 219-220, which correspond to cylinders 261-262 in FIG. 8, are independently operated by the left and right jogger control valves 186, 188, and are extended when ports B and C are connected. Cylinder 221 actuates the No. 2 flipper 75 in FIG. 4, and is actuated by valve 190 the same as valve 164 actuates cylinder 205. Cylinder 222 actuates the No. 3 flipper 68 in FIG. 1, and is controlled by valve 192 in the same manner.
The drag-off arms 65-66 and 70-71 are more correctly an operating part of a different portion of the sawmill, and are therefore not a part of the trimmer section per se. However, it should be noted that their operating cylinders (not depicted) and also the actuating cylinder (not depicted) in the stop assemblies 6 and 73, may be energized by pressure from line 201.
Referring now to FIGS. 10A-F, there may be seen a simplified schematic representation of circuitry suitable for operating the subject sawmill while in either the "automatic" mode, or while in the so-called "manual" mode. Inasmuch as the system is more characteristically described with respect to the "automatic" mode, the following description will be made on that assumption.
Referring again to FIG. 10A, the system may be seen to be actuated by high voltage power supply 100 which, in turn, is connected through a high voltage master switch 101 to the input side of a low voltage master switch 102 which, in turn, actuates a suitable low voltage power supply 103 having its output connected to a low voltage main conductor 103A. All components of the system are preferably driven by low voltage from the low voltage main 103, with the exception of the trimmer saw motors 42, 46, which are connected directly to the output side of the high voltage master switch 101. When a timber 5 impacts against the plate 7 in FIG. 1, this functions to close a limit switch 108 (which is located in the stop assembly 6) to connect low voltage power to the coil of the drag-off relay 224, whereupon power is then connected through the drag-off limit switches 106-107 (in the drag-off assemblies 8-9), and through the manual drag-off return switch 105, to provide a latching circuit for the relay 224. When the relay 224 is actuated, as hereinbefore described, power will now be connected from the low voltage main 103A through the solenoids 161, 163 through a complete circuit to ground or reference as represented by the circuit 245 in FIGS. 10A-F. Solenoids 161, 163 are the actuating units for the left and right drag-off valves 160, 162, and thus, the timber 5 will now be laterally transferred from the roller bed 3 to the deck assembly. Note that the deck actuator switch 110 will now be closed when the timber 5 depresses the pad-type switch 14 to actuate the deck motor 21. Thus, the deck motor 21 will now move the timber 5 along the trimmer deck assembly until the timber 5 clears the pad 14 to re-open the deck actuater switch 110.
As hereinbefore stated, this action will be repeated when the roller bed 3 delivers the next succeeding timber to the plate 7 of the stop assembly 6. It will be noted in this regard, that the deck motor 21 may also be selectively actuated by the operator, by closing switch 112, and that the drag-off assemblies 8-9 may be similarly actuated at anytime by the operator by means of switch 104. In this regard, it should also be noted that, in FIGS. 10A-F, those switches which are operated by the system are depicted in single dashed lines, whereas those switches which are in the control booth with the operator and which are utilized by the operator to selectively control individual component portions of the system are depicted in FIGS. 10A-F by double dashed lines.
It should be noted that the drag-off limit switches 106-107 are re-opened whenever the drag-off arms 8-9 are moved to their extreme extension, and that this breaks the latching circuit for the drag-off relay 224, whereby power is now disconnected from the solenoids 161,163. This may also be accomplished, however, by means of manual drag-off return switch 105, which is interconnected between the drag-off limit switches 106-107 and the drag-off relay 224.
When the deck actuator switch 110 (switch 84 in FIG. 2) is closed, voltage power will now be connected through circuit 112A, the normally closed contacts of the No. 1 flipper relay 225, and the normally closed contacts of the rotator relay 226, to energize the trimmer deck motor 111 (motor 21 in FIG. 1). After the chains 18, of the trimmer deck assembly, carry the timber 5 off of the switch 110, the switch 110 will re-open to break the circuit and de-energize the motor 11, as hereinbefore explained.
If the timber 5 is in a relatively erect position, as illustrated by timber 5B depicted in FIG. 2, this will permit the check switch 113 (switch 16 in FIG. 2) to close, whereby power will be connected from the circuit 103 through the No. 1 flipper return switches 115-116, to close the No. 1 flipper relay 225. Note that power also bypasses the check switch 113 to provide a latched circuit for the No. 1 flipper relay 225 after the check switch 113 is re-opened.
Low voltage power is now coupled from the circuit 103A to the solenoid 115 of the No. 1 flipper control valve 164, which thereupon actuates the No. 1 flipper 17 as hereinbefore described. Note that whenever the relay 225 is energized, this breaks the circuit to the trimmer deck motor 111. Note also that actuation of the No. 1 flipper 17 will open the No. 1 flipper return switch 116 (see switch 96 in FIG. 3) to break the latching circuit to the No. 1 flipper relay 225. Note further that the manual switch 114 may also be used to actuate the No. 1 flipper, and that it may be returned by means of the manual return switch 115.
It should be noted that actuation of the rotator check switch 109 will not condition the rotator 27, because power for the solenoid 167, which actuates the rotator valve 166, arrives by way of the left and right unloader end switches 157-158.
Accordingly, at the beginning of any operating sequence, whether automatic or manual, the operator must employ the rotator start switch 117 to connect power from circuits 103A, 117A and 109A to energize the rotator relay 226, whenever the first timber in the sequence moves to close the normally open contacts of the rotator check switch 109. This will then provide a latching circuit through the rotator return switch 118, circuit 103A, the rotator relay 226, circuit 119A the loader limit switches 119-120, circuit 233J and the first pair of contacts of the rotator relay 226, to connect power to the rotator check switch 109. Thereafter, actuation of the rotator check switch 109, by subsequently arriving timbers, will condition the rotator 27 as hereinbefore explained. Accordingly, whenever the rotator check switch 109 is closed, power will now be applied to the solenoid 167 of the rotator valve 166, by way of the saw-up safety relay 237. Note also that power is now disconnected from the trimmer deck motor 111, as hereinbefore explained.
When the loader turn-on limit switch 151 (switch 243 in FIG. 7) is closed, power is connected through the manual control relay 223, and circuit 233E, to actuate the loader relay 227. Power will also be coupled from circuit 103A through the saw-up safety relay 237, to the solenoids 169,171 of the left and right loader valves 168,170. A latching circuit will now be provided through circuit 233J, the loader limit switches 119,120, circuit 119A, the relay 226, the rotator return switch 118, and the low voltage main circuit 103A. When both loader limit switches 119, 120 are opened, the loader relay 227 will be de-energized and power from circuit 103A will then be coupled through the manual control relay 223, the loader limit switches 120,119, and through circuit 146A, to the coil of the unloader relay 239. A latching circuit for relay 239 will now be provided through circuit 103A, the unloader return switch 147, the tie stop relay 238, circuit 233L the unloader return limit switches 148,149, the primary selection relay 240, and through circuit 146A, to the coil of relay 239. Power may now be coupled from circuit 103A to the solenoids 195, 197 of the left and right unloader valves 194,196.
At this point in the operation, the initial stage of the automatic sequence is complete since the timber 5D is now gripped between the tooth members 51-52 and the two tie stops 55,56, as shown in FIG. 4-5, and since the trimmer saws are manually actuated as previously explained. Accordingly, if the unloader return switch 147 is now opened, this will break the holding circuit for relay 239 to de-energize the solenoids 195, 197, and this will relax and restore the unloaders 49,50, to disengage the timber 5D, to permit use of the No. 2 flipper 75, if desired, and to also permit use of the joggers 57,58.
Power may now be connected from Circuit 103A, through the last contacts of relay 239, circuit 239H, to the No. 2 flipper switch 125, and to the jog left and right switches 123-124. When switch 125 is closed, power will be coupled through relay 237 to the solenoid 191 of the No. 2 flipper valve 190. Similarly, when switches 123-124 are closed, power will be applied to solenoids 187, 189, respectively, to actuate the jog left and right valves 186-188. After the timber 5D has been repositioned as desired, however, the unloader start switch 146 may be closed to cause the timber 5D to be re-engaged between the tooth members 51-52 and the two tie stops 55-56, whereby the timber 5D may now be trimmed as previously explained.
When both unloader end switches 157-158 are closed, power will be connected from circuit 103A to the coil of the unloader safety relay 242. Now, if the left saw-up switch 138 is closed, power will now be coupled from circuits 103A, 139A, and 242D, to energize the left saw-up relay 234, whereupon power will then be coupled from circuit 103A to the solenoid 181 of the left saw lift valve 180. Note that power is also coupled through the relay 234 to circuit 234A, the left saw-up limit switch 142, the left saw-down control switch 141, and circuit 139A, as a holding circuit for relay 234.
The limit switch 142 is intended to provide for cutting only timbers of less than a predetermined size. If the left saw-up switch 138 is held closed while the limit switch 142 opens, however, the saw will ride past the limit switch 142 until it reaches its maximum elevation as hereinbefore explained. To return the left saw, it is then necessary to open the left saw-down switch 141.
If the both-saws-up switch 140 is closed, this will energize the both-saws-up relay 236, whereby power will be coupled through relay 242 and circuit 242D, to energize and latch the relay 234. Similarly, power is coupled through circuit 242A to energize and latch relay 235, and solenoids 181,183 will now both be actuated. Note that if switch 140 is held closed, this will override both limit switches 142,144 as hereinabove explained, and both switches 141,143 will then be required to restore both saws.
When the selection control circuit 246 is actuated as hereinafter explained, this will couple power from circuit 103A, secondary selection relay 241, circuit 241B, through relay 237, circuit 237P, switch 246 to energize the primary selection relay 240. The latching circuit to the unloader relay 239 has now been broken to release the timber 5D, whereupon the unloader end switches 157-158 will be reclosed to again energize the unloader safety relay 242. Power will now be applied from circuit 103A through relay 240 and circuit 242H to energize the tie stop relay 238. This, in turn, couples power from circuit 103A to the solenoid 185, to energize the tie stops valve 184 to lower the tie stops 55-56.
When the tie stops 55-56 reach their lower position, the left and right stops-down limit switches 154-155 will be closed, whereby power from circuit 103A will be coupled through relay 240 and circuit 237J, through relay 238 and circuit 146A, to re-energize the unloader relay 239. The unloader assemblies 49-50 will now be energized to carry the trimmed timber onto the second roller bed assembly 61, as hereinbefore described, and also to close the unloader return limit switches 148-149. This, in turn, will now couple power from circuit 103A through circuit 148A and relay 240 to actuate the secondary selection relay 241 in the selection control circuit 246, as will also be hereinafter explained.
The circuit actuating the primary selection relay 240 is now broken, the relay 238 is released, and the relay 239 is then released. In addition, power will now be coupled from circuit 103A through circuit 148A and switches 148-149, circuit 233M, and through relay 223 and, if the rotator check switch 109 is closed, through circuit 109A to energize the rotator relay 226. The rotator will again be actuated as hereinbefore explained, and the first stage of the automatic sequence will then be repeated.
The operation of the system will now be described with respect to the circuitry depicted in FIGS. 11A-B. To summarize, the operation of this system, while in the automatic mode, may be simply stated in terms of the following steps. In the first step, a timber is carried by the first roller bed section 3 until it impacts the stop plate 7, thereby closing switch 108. In step two, the drag-off assemblies 8-9 are actuated by switch 108 to transfer the timber from the first roller bed section 3 onto the pad assembly 14, to thereby close switch 84 (switch 110). Closure of switch 84 will actuate the trimmer deck motor 21 to thereby carry the timber forward until it clears the pad assembly 14 and releases the switch 84 (switch 110), whereupon the trimmer deck motor 21 is inactivated. If the timber is in erect position whereby it deflects pendulum 88, switch 16 will cause the cylinder 91 to be energized, whereupon the No. 1 flipper rises to rotate the timber, and, coincidentally, actuates switch 96. Closure of switch 96 de-activates the cylinder 91, to restore the No. 1 flipper to its original retracted position. (When switch 84 actuates cylinder 91, it should be noted that this also inactivates the trimmer deck motor 21.).
The next step of the operation will occur when the trimmer deck motor 21 eventually carries the timber onto the rotator 29, to activate the switch 293. This inactivates the trimmer deck motor 21 and also conditions the rotator 29 to operate if (a) the operator closes the rotator start switch 117, or (b) the unloader assemblies 49-50 extend to their maximum travel to close switches 148-149 while transferring a trimmed tie or timber onto the second roller deck 61. Upon the occurrence of either of these alternatives, the rotator 29 will revolve to transfer the timber off of switch 293 and onto the loader arms 30-31. Note that the trimmer deck motor 21 is also disabled whenever the rotator 29 moves out of its normal position.
When the rotator 29 reaches its full revolution to drop the timber onto the loader assemblies 30-31, this also closes switch 243 to cause the loader assemblies 30-31 to shift the timber onto the unloader assemblies 49-50, and also to activate limit switches 119-120 upon reaching maximum extension. When the loader limit switches 119-120 are actuated, this causes the loader assemblies 30-31 to return to their original position, and further causes the unloader assemblies 49-50 to drag the timber into locking engagement with the two tie stops 55-56. In addition, this will also cause the rotator 29 to be revolved to its normal position to accept the next succeeding timber from the trimmer deck assembly, and also to re-enable the trimmer motor 21 to be actuated as hereinbefore described.
This concludes the first stage of the operation. Note that the second stage of the operation cannot begin unless the trimmer saws 38-39 are in a lowered position to actuate the saw-down switches 276.
The operator may now trim the ends of the ties by means of either switch 138, 139 or 140. In either case, this is done manually. The operator may also, at that time, designate which of the various timber deck assemblies to receive the timber then being trimmed, by selecting and closing the appropriate one of switches 300-303 in the control circuit 246. It should be noted that this may be done either before, or after, the trimmer saw blades 38-39 are returned to their normal position, since nothing can be actuated as long as the saw-down switch 276 (and its counter-part switch) is in a relaxed positon.
It should be noted that, if the operator waits until switch 276 is re-activated, then the selection stage will commence whenever one of the deck selection switches 300-303 is closed. Alternatively, if the operator does not wait to close the selected one of the deck selection switches 300-303, then the selection stage will be commenced upon the two saw blades 38-39 being returned to their normal position, and upon the actuation of switch 276 and its counterpart. On the other hand, the operator need not perform the trimming operation if unnecessary. In such a case, if he closes an appropriate one of the deck selection switches 300-303 before closing one of his saw switches 138-140, and while the switch 276 and its counterpart are both actuated, then the following stage of the automatic mode will be initiated at that point.
The second stage of the automatic mode sequence will commence whenever the operator chooses and closes one of the deck selection switches 300-303 as hereinbefore described with respect to the three alternative sequences. In this case, the unloader assemblies 49-50 will relax their grip upon the timber, and will return to their original positions, whereupon their end switches 157-158 will then be closed to cause the tie stop assemblies 55-56 to retract. In addition, it should be noted that closing the No. 1 deck selection switch 300 will cause the stop assembly (not depicted), which is located in the second roller bed assembly 62 for the purpose of regulating input into the first timber deck assembly 64, to be elevated. On the other hand, if the No. 2 deck selection switch 301 has been closed, nothing more will happen at this time. Alternatively, if the No. 3 deck selection switch 302 has been closed, the stop assembly (not depicted) which regulates input into the third timber deck (not depicted) will be elevated. On the other hand, if the No. 4 deck selection switch 303 has been actuated, this would elevate the stop assembly (not depicted) which is intended to serve the fourth tie deck assembly (also not depicted).
When the various tie stops are lowered, they will engage and actuate switches 154-155, whereupon their appropriate unloader assemblies will then respond to shift the timber onto the second roller deck assembly 61. It should be noted, therefore, that when such unloader assemblies reach full extension, the following sequence will occur. The first stage of the automatic sequence will again be initiated as hereinbefore explained, and the various tie stops in the second roller deck assembly 61 will already be in their original elevated positions. In addition, the unloader assemblies will return to their retracted positions.
In addition to the foregoing, one of the following alternatives will also occur. If the No. 1 deck selection switch 300 has been closed, then the "run left" motor control 313 will be actuated to cause the second roller deck assembly 61 to carry the timber resting thereon until it reaches the tie stop (not depicted) in front of the No. 1 timber deck. Impact with the tie stop will, of course, cause the drag-off arms connecting with such timber deck assembly to carry the timber off of the roller bed 61 and onto the tie stacker associated therewith (not depicted), all as hereinbefore described. If the No. 2 deck selection switch 301 has been closed, however, then the No. 2 drag-off arms 65-66 will be activated only, whereby the timber is removed from the roller deck assembly 61 and shifted onto the tie stacker arms 67 associated therewith. If, on the other hand, the No. 3 deck selection switch 302 has been closed, then the "run right" motor control 314 will be actuated to cause the roller deck assembly 61 to carry the timber into engagement with the No. 3 tie stop assembly 73, which, in turn, activates the No. 3 drag-off arms 70-71. Note that the timber will also be shifted onto the tie stacker arms 72 associated therewith. In the fourth alternative, and if the No. 4 deck selection switch 303 has been activated, then the operation will be the same as when the No. 3 deck selection switch 302 was closed, except that the roller deck assembly 61 will carry the timber until it impacts against the tie stop assembly (not depicted) which is associated with the fourth tie deck assembly (also not depicted).
Whenever the drag-off arms for any of the various timber decks are activated, this will produce a low voltage signal to actuate the selection kill relay 308, whereupon the selection control circuit 246 will return to its original condition, and whereupon any elevated stop assembly in the second roller deck assembly 61 will be retracted. Also, the roller deck assembly 61 will then be inactivated, if it is running at that time. Note, however, that the drag-off arms in these various timber deck assemblies are independent of the selection control circuit 246, however, and that they will follow their own sequences.
It will be noted that the saw blades 38-39 are movable laterally as well as horizontally, in order to provide means whereby the ties may be trimmed to different preselected lengths. The blades are normally in what is known as position 1, which is the position of closest spacing and which is usually eight feet. Each may be moved in six inch increments, and therefore, when the left saw blade 39 is moved to position 2, the spacing between the blades will be eight and one-half feet. Consequently, when the left saw blade 39 is moved to position 3, the spacing will be nine feet, and when the left saw blade 39 is moved to position 4, the spacing between blades will be a total of nine and one-half feet. The right saw blade 38 being still in position 1, of course. Accordingly, it will thus be apparent that when the blades are spaced a maximum distance apart, the spacing will be a total of eleven feet.
Inasmuch as the blades are selectively and individually spaced along the axis, this permits variation of the cutting positions of the two blades with respect to the trimmer, as well as variation of the spacing between the two blades. This feature of the apparatus permits the blades to be positioned so as to accommodate a timber which is somewhat off center along the unloader arms 49-50, and avoids the necessity of using the jogger assemblies in every instance.
Referring again to FIGS. 10A-F, it will be seen that positioning of the two saw blades may be accomplished by means of the following procedure.
The left saw blade is normally positioned at position 1 as represented by normally closed left saw position 1 control switch 129. To move the left saw blade 39 to position 2, the operator will close the left saw position 2 switch 128, thereby connecting power from low voltage main conductor 103A to the solenoid of the left saw position 1 relay 228. This provides a latching circuit for relay 228, by connecting power from the low voltage conductor 103A through the normally closed contacts of the left saw position 3 relay 230 and the normally closed contacts of the left saw position 2 relay 229, to the solenoid of the left saw position 1 relay 228. Power will now be connected to the solenoid 173, of the left inside saw shift valve, thereby moving the saw to the position selected.
If it is desired to move the left saw blade 39 to position 3, this is effected by closing the left saw blade position 3 switch 127, thereby connecting power from the low voltage conductor 103A to the solenoid of the left saw position 2 relay 229, thereby closing this component. A latching circuit is now provided because the left saw position 1 relay 228 has been opened. In particular, left saw position 1 switch 129, which connects power from the low voltage main circuit 103A through the now latched contacts of relay 229 and the normally closed contacts of relay 230, to reach the solenoid of relay 229. Solenoid 173 has been inactivated, but solenoid 175 is now energized to move the saw blade accordingly.
If it is desired to move the left saw blade 39 to the outermost position 4, this may be accomplished by closing left saw position 4 switch 126 to connect power to the solenoid of the left saw shift position 3 relay 230. A latching circuit for relay 23 will now be provided by coupling power from the low voltage main circuit 103A, through the left saw position 1 switch 129, the normally closed contacts of the left saw shift position 1 relay 228, the now closed contacts of the left saw shift position 3 relay 230, the normally closed contacts of the now re-opened left saw shift position relay 229, to the coil of the left saw shift position 3 relay 230. It will now be seen that the left saw blade 39 will be shifted to the maximum outermost position due to activation of both solenoids 173 and 175.
The left saw blade 39 may be returned to its original or No. 1 position, by merely opening the normally closed left saw position 1 switch 129. When this is done, this breaks whatever latching circuit may have been previously established with respect to any one of relays 228-230, whereupon these components will return to their normal position, and whereupon power will be discontinued from either one or both of the solenoids 173 and 175.
As hereinbefore explained, it is not necessary to position the left saw blade 39 according to any particular sequence, and therefore, the foregoing description was intended for illustration purposes only. In actuality, the left saw blade 39 may be positioned to any position, from any position, as may be desired by the operator. In other words, if it is desired to move the left saw blade to position 2, all that is required is that the operator actuate the left saw position 2 switch 128.
The right saw blade 38 may be moved in precisely the same manner, and by means of precisely the same type of components. In other words, the right saw position 1 switch 130 corresponds functionally to the left saw position 1 switch 129, and the right saw position 2 switch 131 corresponds functionally to the left saw position 2 switch 128. Similarly, the right saw position 3 switch 132 corresponds functionally to the left saw position 3 switch 127, and the right saw position 4 switch 133 corresponds functionally to the left saw position 4 switch 126.
The right inside saw shift solenoid 177, which actuates the right inside saw shift valve 176, corresponds functionally to the left inside saw shift solenoid 173. Likewise, the right outside saw shift solenoid 179 which actuates the right outside saw shift valve 178, corresponds functionally to the left outside saw shift solenoid 175. In addition, the right saw shift position 1 relay 231 corresponds functionally to the left saw shift position 1 relay 228, and the right saw shift position 2 relay 232 corresponds to the left saw shift position 2 relay 229. Likewise, the right saw shift position 3 relay 233 corresponds to the left saw shift position 3 relay 230.
Referring again to FIGS. 10A-F, it will be noted that the No. 3 flipper switch 150 may be closed to connect power from the low voltage circuit 103A to the solenoid 193 which, in turn, actuates the No. 3 flipper valve 192. In addition, the trimmer stops valve control switch 145 may be used by the operator to connect power from the low voltage main circuit 103A through the normally closed contacts of the unloader safety relay 242 to the solenoid of the tie stop relay 238. When this component is actuated, this couples power from the low voltage and main circuit 103A to the tie stops valve solenoid 185, to actuate the tie stops valve 184. This, in turn, lowers both tie stops accordingly. The right saw-up control switch 138 corresponds functionally to the left saw-up control switch 139, by permitting the operator to couple the power from the low voltage control circuit 103A through the normally closed contacts of the unloader safety relay 242 to the solenoid of the tie stop relay 238, all as hereinbefore explained. The function of the manual No. 1 flipper control switch 114 is to couple voltage power from the circuit 103A to actuate the No. 1 flipper relay 225.
As hereinbefore stated, the circuitry depicted in FIGS. 10A-F will show that the system is normally within the so-called automatic mode. If it is desired to go to the manual mode, the operator will close the manual control switch 159, thereby connecting power from the low voltage main circuit 103A to the solenoid of the manual control relay 223. It will be noted that, since the automatic control switch 176 is normally closed, this provides a latching circuit to hold the manual control relay 223 in an energized condition, even after the manual control switch 159 has been released by the operator.
When the manual control relay 223 has been energized, as hereinbefore explained, low voltage power will be connected from the low voltage circuit 103A to the input side of the two deck actuator switches 110, 112. As hereinbefore explained, whenever the rotator deck switch 109 is positioned by the presence of a timber, the the trimmer deck is supposed to be inactivated. When the system is in the manual mode, however, the deck actuator control switch 112 may now be closed to energize the trimmer deck notwithstanding. A further effect is that the loader turn-on limit switch 151 will now be disconnected from its source of power, thereby preventing the loaders 30,31 from being inadvertently activated. In addition, power is now disconnected from both the left and right loader limit switches 119, 120, thereby prohibiting the unloaders 59, 60 from being actuated, and also preventing the loaders 30, 31 and the rotator 29, from returning to their original positions.
As hereinbefore stated, it is a feature of this apparatus that the tie is fixedly clamped in position before and during the trimming operation in order that this function may be performed with safety to personnel in the area. Referring again to FIGS. 10A-F, it will be seen that this function is performed by the saw-up safety relay 237 in conjunction with the left and right saw-down limit switches 152-153. These two switches are normally closed, but they are held open by the position of the respective ones of the two saw blades 38-39 being in their lowered positions. When either or both of these two saw blades 38-39 are lifted from their lowered positions, however, this will release one or both of the left and right saw-down switches 152-153, thereby coupling power from the low voltage main circuit 103A to the solenoid of the saw-up safety relay 237, as hereinbefore explained. When the saw-up relay 237 is actuated, this disconnects power from the solenoids 187,189 of the jog left and jog right valves 186,188, and also from the solenoid 191 of the No. 2 flipper valve 190. In addition, power will now be connected to the solenoids 195, 197 of the left and right unloader valves 194, 196, thereby preventing the left and right unloaders 59,60 from being actuated to release their grip upon the timber then being subjected to cutting by the rising timber blades 38-39. In addition to the foregoing, it will be noted that power is also disconnected from the solenoid 67 of the rotator valve 166, and also from the solenoids 169, 167 of the left and right loader valves 168, 170. In addition, it will be noted that the energized position of the saw-up safety relay 237 also prevents the primary selection relay 240 from being energized. The purpose of this feature is to permit the operator to select the appropriate tie deck to receive the timber being trimmed, even before the trimming operation has been completed, as hereinbefore mentioned.
Referring again to FIGS. 10A-F, it should be noted that the trimmer deck assembly may be selectively activated by the deck actuator manual switch 112. Note also that the rotator return switch 118 corresponds to switch 243 in FIG. 7. See also the loader manual return and start switches 121, 122, which are used to selectively activate the loaders 30, 31, and the left and right saw on-off switches 134, 135 which are used to activate the left and right saw motors 136, 137. See also the trimmer stops down switch 145 in FIGS. 10A-F, which corresponds to the switch 271 depicted in FIG. 6.
It will be apparent from the foregoing that many other variations and modifications may be made in the structures and methods described herein without substantially departing from the essential concept of the present invention. Accordingly, it should be clearly understood that the forms of the invention described herein and depicted in the accompanying drawings, are exemplary only and are not intended as limitations in the scope of the present agreement.
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An improved trimmer section is provided for use in a sawmill, together with method and means for automatically selecting timbers and the like to be trimmed, and for automatically routing trimmed timbers to a preselected one of a plurality of different storage and loading points in the sawmill. In particular, the operator is required to select which of several stations is to receive each timber after it has been cut to a designated length. Thereupon, the timber is automatically transferred through several stages of mechanical manipulation to the designated station while, simultaneously therewith, another un-trimmed timber is promptly conducted to the trimming saws. Actuation of the entire operation is effected by merely selecting the station to receive the trimmed timber, since the cycle will repeat as long as there are timbers to be trimmed.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a healthy drink containing mineral components such as sodium, calcium, magnesium, potassium, iron and tannin, and polyphenol components contained in azuki bean, while containing a small amount of energy sources such as sugar, fat and protein, and its production method.
[0003] 2. Description of the Related Art
[0004] Heretofore, azuki bean is known as nutritious bean containing energy sources such as sugar, fat, and protein, and is used as a raw material for production of azuki-bean soup (Shiruko), bean jam, sweet jelly of beans (Yokan) etc.
[0005] On the other hand, recently, by changing life environments and eating habits, increase of the diseases from life habits such as increase of fats, arteriosclerosis, high blood pressure and diabetes, caused by excessive caloric intake, became a social concern. Therefore, as a solution, much attention is paid on the so-called healthy drink which can easily provide vitamins and minerals with a low calorie content.
[0006] As such a healthy drink, drinks made from beans such as soy bean, black soy bean and azuki bean which contain vegetable protein, various vitamins, fats and minerals, providing a well balanced nutrition have been proposed (e.g. see publication of Japanese Patent Laid-Open H11-183738, H2000-189123).
[0007] However, those drinks from beans proposed heretofore are inclined rather to use as an alternative of coffee as table luxuries, and use black soy bean as an indispensable material, while using azuki bean only as a supplemental ingredient for sweet and flavor.
SUMMARY OF THE INVENTION
[0008] The present invention, considering above situation, aims for providing a new healthy drink effectively utilizing azuki bean (small red bean) which is rich in mineral components such as sodium, calcium, magnesium, potassium, iron and tannin, as well as polyphenol components, and its production method.
[0009] The inventors of the present invention, as a result of an intensive study placing focus on azuki bean which is rich in mineral components such as sodium, calcium, magnesium, potassium, iron, tannin and polyphenol components, found that a new healthy drink with a brilliant red color of azuki bean and a plain flavor can be produced by extracting effectively mineral and polyphenol components through heating azuki bean under a certain condition while limiting extraction of sugar, fat and protein, and further removing an astringency from extracted liquid which contains minerals and polyphenols by aging the extract under a suitable condition, thus completing the present invention.
[0010] Namely, the healthy drink made from azuki bean of the present invention is characterized by containing the extracted components of azuki bean, and the extracted components are essentially mineral components such as sodium, calcium, magnesium, potassium, iron, tannin and polyphenol components.
[0011] Function of each of above mentioned components contained in the healthy drink of the present invention are described in the following:
[0012] [Sodium]
[0013] mitigates excitement of muscles and nerves, maintains constant osmotic pressure of extracellular fluid such as plasma, maintains alkaline condition of body, helps secretion of digestive fluid, and prevents lack of appetite, fatigue, and mental unstability.
[0014] [Calcium]
[0015] forms hard texture such as bone and tooth, make blood alkaline affecting on the blood coagulation, and promotes contraction of cardiac muscle.
[0016] [Magnesium]
[0017] enhances stimulus excitement of muscle, while on the other hand sedates the same. Activates some kind of enzyme, helps prevention of cardiopalmus caused by vasodilation.
[0018] [Potassium]
[0019] controls function of heart and muscles, as well as maintains osmotic pressure of intracellular fluid, prevents myasthenia due to decrease of myodynamia and ileus, prevents cystectacy, prevents parareflexia, improves allergic habit of body, helps intracorporeal spodophorous. With sodium, controls intracorporeal water balance and maintains normal heart beat rhythm.
[0020] [Iron]
[0021] carries oxygen via hemoglobin in red corpuscle as well as takes oxygen in blood into cells via myoglobin of liver. Distributed widely in cells of whole body, involved in activation of oxygen and promotes combustion of nutrients. Prevents anemia, fatigue, and hypoplasia of baby.
[0022] [Tannin]
[0023] has anti-oxidation effect, suppresses lipoperoxide, and carcinogenesis.
[0024] In order to make those functions effectively demonstrated, and to provide a suitable flavor and fragrance as a drink at the same time, preferred range of content for each component are as follows; sodium: 0.5-1 mg/100 ml, calcium: 1-2 mg/100 ml, magnesium: 1-2 mg/100 ml, potassium: 10-20 mg/100 ml, iron: 0.01-0.05 mg/100 ml, tannin: 25-35 mg/100 ml. Out of those ranges, the drink becomes too much astringent and the functions of each component may not be demonstrated.
[0025] Particularly preferred contents are as follows; sodium: 0.8 mg/100 ml, calcium: 1.3 mg/100 ml, magnesium: 1.6 mg/100 ml, potassium: 16 mg/100 ml, iron: 0.03 mg/100 ml, tannin: 30.0 mg/100 ml, whereby function of each component are fully demonstrated with a suitable flavor and fragrance of a drink.
[0026] Quality of azuki beans, however, generally depends on its bleeding, growing district, harvest year and storage method. In addition, the bean changes its seed ratio (the ratio of its peel to the rest part) by self-decomposition of starch and protein to maintain its own life. Considering such characteristics peculiar to azuki bean, for production of the healthy drink made from azuki bean of the present invention, the inventors of the present invention intensively studied the method of preventing effluence of a component having relatively long molecular chain which has strong astringency and a bitter taste, and as the result, found that after extraction of minerals and polyphenols from azuki bean, subjecting the extract to heating process provides a mellow flavor by bonding relatively short molecular chains of the components of astringency and bitter taste, and furthermore, by aging for a certain period of time after the heating process, its flavor and fragrance become stabilized and suitable as a drink, thus completing the present invention.
[0027] Namely, as a preferred production method of the healthy drink made from azuki bean, a method is proposed comprising first washing the desired amount of azuki beans, followed by extraction of the beans under a certain heating condition to obtain an extracted liquid containing minerals and polyphenols from azuki bean, and after dilution of the extracted liquid to a certain concentration, the diluted liquid is filled up in a container which is then heated and cooled and left for aging.
[0028] Extraction in the above mentioned method is preferably conducted by boiling down process using 80-100° C. hot water for 20-60 minute. Under this condition, mineral components and polyphenol components in azuki bean are efficiently extracted while the extraction of sugars, fats and proteins are prevented.
[0029] For effectively demonstrating the function of each component and providing flavor and fragrance suited as a drink, it is preferred to adjust dilution of the aforementioned extracted liquid as follows; sodium: 0.5-1 mg/100 ml, calcium: 1-2 mg/100 ml, magnesium: 1-2 mg/100 ml, potassium: 10-20 mg/100 ml, iron: 0.01-0.05 mg/100 ml, tannin: 25-35 mg/100 ml.
[0030] Heating of the closed container in the above mentioned method is preferably conducted at 110-130° C. for a period of 30-40 minutes. This condition develops color in the liquid in the container and remove astringency to provide a flavor suited for drink.
[0031] Aging in the closed container in the above mentioned method is preferably conducted at 15-30° C. for a period of 3-7 days. Under this condition, color of the liquid in the container further deepens and flavor is improved, thus providing taste, fragrance and color suited for drink.
[0032] The production method of the healthy drink made from azuki bean of the present invention is further proposed comprising first washing a desired amount of azuki beans, followed by extraction of the beans using 80-100° C. hot water in a period of 20-60 minutes for extracting mineral components and polyphenol components from azuki bean, and then heating the diluted extract at 120-135° C. in a period of 5-40 minutes to develop color and flavor of the diluted extract, followed by cooling and filling it up in a container sealed hermetically, and aging at 15-30° C. in a period of further 3-7 days for deepening the color of the liquid in the container and stabilizing the flavor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] [0033]FIG. 1 shows a block flow diagram of an example of the production method of the present invention.
[0034] [0034]FIG. 2 shows the result of the sensual tests for color, fragrance, taste and bitter taste of the healthy drink of the present invention.
[0035] [0035]FIG. 3 shows a comparison of the contained components in the healthy drink of the present invention and in a mineral water in the market.
[0036] [0036]FIG. 4 shows a block flow diagram of another example of the production method of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] The present invention related to a healthy drink made from azuki bean and its production method is illustrated in more detail by reference to the following examples.
[0038] Example 1 as shown in FIG. 1 will be described as follows. Although any azuki bean for food use can be used in the present invention, “Hokkai Azuki” was used in this example.
[0039] 30 kg of this azuki beans having good color and shape were selected, washed with water, and thrown into 300 kg of water in a pot-like container where the beans were boiled at 80-100° C. for 20-60 minutes, preferably at 90-100° C. for 30-60 minutes and an extracted liquid containing mineral components and polyphenol components was obtained wherein extraction of sugars, fats and proteins were suppressed.
[0040] After removing unnecessary components such as fibrous tissues, the extract was diluted with water to contain sodium: 0.8 mg/100 ml, calcium: 1.3 mg/100 ml, magnesium: 1.6 mg/100 ml, potassium: 16.3 mg/100 ml, iron 0.03 mg/100 ml, tannin: 30.0 mg/100 ml, sugar: 0.2 g/100 ml, while containing almost no fats and proteins.
[0041] This adjusted liquid was filled up in a sealed container and heated at 110-130° C. for 30-45 minutes, preferably at 125° C. for 35-40 minutes. By this heating, the liquid in the container developed red color of azuki, and astringency was removed so that a flavor of a drink was generated.
[0042] Next, the above container was cooled by water for 15-20 minutes, and then subjected to aging at room temperature (15-30° C.) for 3-7 days. By this aging, the liquid in the container further deepened the red color of azuki bean as well as its flavor and fragrance were stabilized making it suitable as a drink.
[0043] The drink thus obtained contained sodium: 0.8 mg/100 ml, calcium: 1.3 mg/100 ml, magnesium: 1.6 mg/100 ml, potassium: 16.3 mg/ 100 ml, iron: 0.03 mg/100 ml, tannin: 30.0 mg/100 ml, while containing 0.2 g/100 ml of sugars and almost no fats and proteins, providing a new healthy drink containing mineral components and polyphenol components from azuki bean and almost without sugars, fats and proteins with a brilliant red color originated from azuki bean.
[0044] A trial drinking of thus obtained healthy drink by 30 men and women of 20-60 years of age was conducted for evaluation of four items, namely, its color, fragrance, taste and bitter taste, the result of which is shown in FIG. 2. Evaluation method was a numerical marking with respect to each of four items of color, fragrance, taste and bitter taste, giving 1 point for bad, 2 points for more or less bad, 3 points for ordinal, 4 points for more or less good and 5 points for good, and the average points were marked as evaluation point in the table.
[0045] As a result of this evaluation test, irrespective of age and sex, average points of 3 or more was marked for color, fragrance, taste and bitter taste.
[0046] On the other hand, the samples with less and more contents of each components than those as designated in the present invention (potassium: 10-20 mg/100 ml, iron: 0.01-0.05 mg/100 ml, tannin: 25-35 mg/100 ml, sodium: 0.5-1 mg/100 ml, calcium: 1-2 mg/100 ml, magnesium: 1-2 mg/100 ml) were prepared and subjected to the same evaluation test as described above. As the result, inferior evaluation points than those marked in FIG. 2 were obtained.
[0047] [0047]FIG. 3 shows a comparison of the components contained in the healthy drink (Example) of the present invention and those in a mineral water (Comparative Examples 1-3) available in the market. From this comparison it is shown that although the mineral water in the market contains sodium, calcium, magnesium, it contains less or no potassium, iron and tannin, indicating that the effect of the healthy drink of the present invention is not obtained.
[0048] Example 2 shown in FIG. 4 will be explained next in detail. In this example, an extract was obtained from azuki beans in the same manner as described in Example 1, and the extract was diluted to give an adjusted liquid containing sodium: 0.8 mg/100 ml, calcium: 1.3 mg/100 ml, magnesium: 1.6 mg/100 ml, potassium: 16.3 mg/100 ml, iron: 0.03 mg/100 ml, tannin: 30.0 mg/100 ml, sugar: 0.2 g/100 ml, with almost no fats and proteins.
[0049] Then the liquid was heated at 120-135° C. and, after that, kept for 5-40 minutes. By this heating and keeping, the liquid developed red color of azuki bean and astringency was removed, providing a flavor suited as a drink.
[0050] After cooling the liquid, it was filled up in a can as a container for drink and sealed hermetically, followed by aging at 15-30° C. for further 3-7 days. By this aging, red color of azuki bean was deepened, flavor and fragrance were stabilized in the canned liquid, which thus became suitable for drink.
[0051] The drink in the container thus obtained, same as the Example 1, contained efficiently the mineral components and polyphenol components from azuki bean, while sugars, fats and proteins were suppressed as much as possible, providing a new drink with a brilliant red color originated from azuki bean.
[0052] With the healthy drink of this example, evaluation was made also for color, fragrance, taste and bitter taste, in the same manner as described in Example 1, and obtained the same result as in Example 1.
[0053] The preferred embodiments of the present invention related to a healthy drink and its production method are described with examples as above. However, the present invention is not limited to those examples, and variations are possible within the technical concepts.
[0054] Moreover, the healthy drink of the present invention can be used, not only for a drink, but also as a cooking water for making breads, noodles, rice, Japanese cakes, cakes, household cooked dishes and so on.
[0055] Furthermore, using the healthy drink of the present invention as a base component, a healthy drink can be prepared by adding effective components extracted from soy beans and other beans or other minerals, vitamins and polyphenols.
[0056] It is obvious that the production method for the healthy drink of the present invention is not limited to those described above, but also applied to various forms of the product such as diluted drinks if desired by consumer, or processing the extracted liquid to a powder or particles for an instant drink, by employing corresponding production methods, starting from washing, heating, extraction of minerals and polyphenols from azuki bean under a certain conditions and adjusting concentration of the components.
[0057] The healthy drink of the present invention, as described above, is a new drink containing mineral components contained in azuki bean such as sodium, calcium, magnesium, potassium, iron, tannin and polyphenol components, while inclusion of sugars, fats and proteins are suppressed as far as possible, which significantly contributes for promotion of health and for improvement of diet of the today's people by easy ingestion of various minerals and polyphenols while minimizing calorific intake. In addition, it is a new and easy drink as it brings about a mellow flavor originated from sweetness of azuki bean and red color thus having a high commercial value accepted by a wide range of customers regardless of age and sex.
[0058] It has many advantages such as controlling function of heart and muscles, improving allergic habit of body, intracorporeal spodophorous, preventing anemia and fatigue, suppression of carcinogenesis etc., as it contains especially potassium, iron, and tannin.
[0059] The production method related to the present invention enables to obtain the healthy drink having above mentioned effects in a simple way and in a short time, and is suitable especially for mass production of a canned drink.
[0060] Having described specific preferred embodiments of the invention with reference to the accompanying drawings, it will be appreciated that the present invention is not limited to those precise embodiments, and that various changes and modifications can be effected therein by one of ordinary skill in the art without departing from the scope of the invention as defined by the appended claims.
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The object of the present invention is to provide a new healthy drink effectively utilizing azuki bean which is rich in mineral components and polyphenol components, and its production method. Washing a desired amount of azuki beans and extracting them under a certain heating condition to obtain an extracted liquid containing minerals and polyphenols from azuki bean, diluting the extracted liquid for adjusting concentration and filling it up in a closed container, heating and cooling the liquid in the closed container, followed by aging, to obtain a healthy drink containing sodium, calcium, magnesium, potassium, iron, tannin originated from azuki bean.
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[0001] This application is a continuation of U.S. patent application Ser. No. 13/163,392, filed Jun. 17, 2011, which claims the benefit under 35 USC section 119 of U.S. Provisional Application No. 61/356,365, filed on Jun. 18, 2010, each entitled “SERS Reporter Molecules and Methods,” the contents of which are hereby incorporated by reference in their entirety and for all purposes.
BACKGROUND
[0002] Certain spectroscopy techniques feature the enhancement of a spectroscopic signal through electromagnetic interaction at a surface. Representative surface enhanced spectroscopic (SES) techniques include, but are not limited to surface enhanced Raman spectroscopy (SERS) and surface enhanced resonance Raman spectroscopy (SERRS). In SERS or SERRS, a metal or other enhancing surface will couple electromagnetically to incident electromagnetic radiation and create a locally amplified electromagnetic field that leads to 10 2 -to 10 9 -fold or greater increases in the Raman scattering of a SERS active molecule situated on or near the enhancing surface. The output in a SERS experiment is the fingerprint-like Raman spectrum of the SERS active molecule. A SERS active molecule may be alternatively referred to herein as a reporter molecule or reporter.
[0003] SERS and other SES techniques can be implemented with particles such as nanoparticles. For example, gold is a SERS enhancing surface, and gold colloid may be suspended in a mixture to provide for enhanced Raman spectrum detection. SERS may also be performed with more complex SERS-active nanoparticles, for example SERS nanotags, as described in U.S. Pat. No. 6,514,767, No. 6,861,263, No. 7,443,489 and elsewhere.
[0004] Although SERS techniques leverage the enhancement phenomenon described above, it is still important for many diverse implementations that the Raman spectrum or signal be as great or bright as possible. Certain known reporter molecules do not return as strong a signal as may be desired in solution, when used with a colloidal enhancing surface, when incorporated into a more complex tag type particle, on an enhancing substrate or otherwise.
[0005] The present invention is directed toward overcoming one or more of the problems discussed above.
SUMMARY
[0006] One embodiment is a SERS reporter molecule comprising a reporter molecule having a length sufficiently short to fit into a crevice formed by the enhancing surfaces of adjacent enhancement particles; and a conjugated path length which is as large as possible, provided the overall molecule length is maintained sufficiently short to fit into the crevice formed by the enhancing surfaces of adjacent enhancement particles.
[0007] Another embodiment is a SERS tag comprising a core comprising at least two aggregated particles of a SERS enhancing material wherein the contact point between the particles defines a crevice; and a reporter molecule having a length sufficiently short to fit into the crevice and a conjugated path length which is as large as possible, provided the overall reporter molecule length is maintained sufficiently short to fit into the crevice.
[0008] Another embodiment is a method of selecting a SERS reporter molecule to optimize the enhancement of the SERS signal provided by said reporter molecule upon excitation in association with a particulate or colloidal enhancing surface, said method comprising: selecting or fabricating a reporter molecule length to be sufficiently short to fit into a crevice formed by the enhancing surfaces of adjacent enhancement particles; and selecting or fabricating the reporter molecule to have as high a conjugated path length as is possible provided the overall molecule length is maintained sufficiently short to fit into the crevice formed by the enhancing surfaces of adjacent enhancement particles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates SERS enhancement vs. reporter molecule length. (top) Structures of the reporter molecules studied, along with their names and lengths. (bottom) SERS enhancements using 785-nm excitation of various reporter molecules on 90-nm Au colloid that was aggregated in the presence of the reporter.
[0010] FIG. 2 illustrates a simulated 90 nm Au colloid dimer hot spot. (left) Electric near-field enhancement created in the junction of a touching 90 nm Au colloid dimer. (right) Electric near-field enhancement as a function of the distance, d, from the junction.
[0011] FIG. 3 illustrates curve fitting of SERS spectra. Comparison of an experimental SERS spectrum of D1 on 90-nm Au colloid and the curve-fit to this spectrum generated by the algorithm used in analysis.
[0012] FIG. 4 illustrates enhancements of D-set of reporter molecules. (top) Schematic of the reporter molecules studied, along with their names and lengths. SERS enhancement factors of the (middle) 1600 cm −1 and (bottom) 1000 cm −1 peak using 633, 785, and 1064-nm excitation of the various reporter molecules on 90-nm Au colloid that was aggregated in the presence of the reporter. Lines are power law fits to the data points.
[0013] FIG. 5 illustrates absorbance spectra from each series of measurements on (left) D1 and (right) D6. (top) Spectra taken before (red), during (green), and after (blue) SERS measurements show little variability over the course of the measurements. (bottom) Sample-to sample variation demonstrates differences in the aggregation state of each sample. The data are taken from two different instruments, leaving a small gap where spectral data is unavailable. A few of the NIR spectra are missing due to some temporary instrument problems.
[0014] FIG. 6 illustrates enhancements of P-set of reporter molecules. (top) Schematic of the reporter molecules studied, along with their names and lengths. (bottom) SERS enhancement factors of the 1600 cm −1 peak using 633, 785, and 1064-nm excitation of the various reporter molecules on 90-nm Au colloid that was aggregated in the presence of the reporter. Lines are power law fits to the data points.
[0015] FIG. 7 the distance of the molecule from the junction as a function of molecule length for different sizes of colloid. This plot assumes that the Au aggregates are perfect spheres with one point of contact, and that the molecules align themselves perpendicular to the plane separating the two spheres.
[0016] FIG. 8 illustrates maximum SERS enhancement on different sized colloid. (Left) SERS enhancement as a function of molecule length using 633, 785, and 1064-nm excitation on 40, 60, 90, and 120-nm Au colloid. Lines are power-law fits to help guide the eye. (Right) The same data plotted for each colloid size and on a log scale with linear fits to guide the eye.
[0017] FIG. 9 illustrates calculated extinction cross-sections of touching Au colloid dimers immersed in water. (Top) Extinction of a dimer of 90-nm Au nanoparticles with an overlap, D, of 1 nm to simulate the contact area of the two nanoparticles. Two different dimer orientations relative to the polarization of the incoming light are considered. (Bottom) Calculated extinction of dimer particles with different overlaps; a spectrum of the extinction expected from two non-interacting nanospheres is included for comparison.
[0018] FIG. 10 illustrates SERS enhancements of 1600 cm −1 Raman peak. (Left) Enhancement at the center of a molecule oriented parallel to the dimer axis and bound to each nanoparticle surface at either end for dimers of 40, 60, 90, and 120-nm Au nanospheres and using 633, 785, and 1064-nm excitation wavelengths. (Right) Electromagnetic near-field enhancement of a (top) 40 nm dimer with D=1.33 nm, and a (bottom) 120 nm dimer with D=4 nm.
[0019] FIG. 11 illustrates the structure and size of reporters used in one aspect of the study.
[0020] FIG. 12 illustrates the synthesis of a selected reporter molecule.
[0021] FIG. 13 illustrates the Intensity of highest Raman peak for each reporter; 0.1 M solutions in DMF. Values corrected for background.
[0022] FIG. 14 illustrates a comparison of SERS intensity for the highest peak for each reporter.
[0023] FIG. 15 is a SEM images of Klarite substrates.
[0024] FIG. 16 illustrates a comparison of colloid and substrate SERS intensity for the highest peak for each reporter.
[0025] FIG. 17 is a schematic representation of the positioning of different sized reporters around the contact area of aggregated particles.
[0026] FIG. 18 illustrates enhancement factors for selected reporter molecules.
DETAILED DESCRIPTION
[0027] Unless otherwise indicated, all numbers expressing quantities of ingredients, dimensions reaction conditions and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about”.
[0028] In this application and the claims, the use of the singular includes the plural unless specifically stated otherwise. In addition, use of “or” means “and/or” unless stated otherwise. Moreover, the use of the term “including”, as well as other forms, such as “includes” and “included”, is not limiting. Also, terms such as “element” or “component” encompass both elements and components comprising one unit and elements and components that comprise more than one unit unless specifically stated otherwise.
[0029] Known prior art marking or detection methods which utilize SERS typically rely upon a reporter molecule or dye with known SERS-active characteristics. For example, a known SERS-active chemical can be added as a dye to mark fuel and a subsequent SERS spectrum obtained when the SERS-active dye is associated with a SERS-active metal particle or substrate. Only a limited number of SERS active chemicals are known.
[0030] Many of the examples herein are described with respect to SERS. It must be noted however that the methods, compositions and reporters disclosed herein are equally applicable to SERRS, SEHRS, SEF, SEHRRS, SHG, SEIRA, SPASERS, or other surface enhanced or plasmon enhanced SES techniques.
[0031] One aspect of SERS that is often overlooked when carrying out fundamental SERS studies is the role of the Raman-active reporter molecule. There are several requirements placed upon the molecule if it is going to generate a large or bright SERS signal.
The molecule should have an inherently large Raman cross-section. The molecule must reside on or very close to the enhancing surface. Maximum enhancement is obtained for vibrational modes that are oriented parallel to the polarization of the exciting radiation. Maximum enhancements are obtained for molecules which reside in “hot spots” on the SERS surfaces.
[0036] This last detail results in certain types of molecules performing better or worse as practical reporters than would be expected based upon Raman cross-section alone.
[0037] It has been determined that there is a correlation between the size of a reporter molecule and the subsequent SERS enhancement achievable on Au nanospheres aggregated in situ. For example, FIG. 1 shows that as the length of the reporter molecule increases, the calculated enhancement factor decreases. In contrast, when SERS signals from these same molecules are measured on Klarite™ substrates, enhancement was found to be independent of reporter molecule length. The relationship between SERS enhancement and molecule size on aggregated Au colloid has been explained by the ability of the molecule to fit into the regions of enhanced electromagnetic near fields, or “hotspots,” created by the aggregated Au nanospheres; Mcmahon, J. M.; Henry, A. I.; Wustholz, K. L.; Natan, M. J.; Freeman, R. G.; Van Duyne, R. P.; Schatz, G. C. Gold nanoparticle dimer plasmonics: finite element method calculations of the electromagnetic enhancement to surface-enhanced Raman spectroscopy. Analytical and Bioanalytical Chemistry 2009, 394 (7), 1819-1825. The hotspots created by aggregating Au colloid are located in the crevices formed by the aggregated particles, and the enhanced near fields therein rapidly decrease as the distance from the crevice increases (See for example the Simulation of FIG. 2 ).
[0038] Although reporter molecules that are small in size are able to access the hotspots, larger molecules have more difficulty fitting into a crevices. Therefore, the near field intensity experienced by larger molecules is relatively lower, resulting in decreased SERS enhancement factors. In contrast, Klarite Au surfaces give lower overall enhancement, due to a broader variety of surface geometries. The “hotspots” on these surfaces are not as hot, or as geometrically restrictive. These results demonstrate that SERS reporter molecule size is a crucial factor to be considered when optimizing SERS surfaces, particularly as the enhancement factors become larger.
[0039] Although the overall trend of decreasing enhancement with increasing molecule size is clear, upon closer inspection, there are some inconsistencies. For instance, the smallest molecules studied did not have the largest enhancements. In addition, there were a number of molecules studied with approximately the same length that had significantly different enhancements. However, when only molecules with the same terminal functional groups and similar structures are considered, the trend appears to be more consistent.
[0040] The chemical structure of the reporter molecule could influence the resultant SERS enhancement in a number of ways. First, the SERS enhancements in the experiments described below arise from the hotspots formed by Au nanospheres that are aggregated in the presence of the reporter either by the molecule itself or by salt that is added to the solutions. Different chemical structures of the molecules may induce different degrees or kinds of aggregation. For instance some molecules may favor forming small aggregates of only a few particles, while others may favor forming large aggregates of tens of particles. The kinds of aggregates formed are probably determined by the mechanism by which the molecule induces aggregation (e.g. electrostatic interactions, covalent bonding to the colloid surface, etc.). Different functional groups within the molecule may also cause the molecule to orient itself differently in the crevices. The molecular orientation in relation to the gradient of the enhanced electromagnetic near field determines which of the molecule's Raman modes are enhanced, and to what degree. The functional groups will also affect the affinity of the molecule to the colloid surface, thereby affecting the number of molecules contributing to the SERS signal.
[0041] The experiments discussed below were carried out in order to isolate the impact of molecule size on the resultant SERS enhancements for selected SERS system. Two different sets of molecules were carefully chosen so that the molecules within each set contained the same terminal functional groups and no other functional groups which would compete for competition to Au surfaces. The molecules were also similar in structure so that similar Raman modes in each molecule could be compared. SERS measurements were taken using three different excitation wavelengths to rule out the possibility that molecular resonances were affecting the results. To probe the importance of the hotspot accessibility more, the experiments were also performed on Au nanospheres of different sizes. The different radii of curvature in these samples should allow reporter molecules of different sizes to penetrate into the hotspots in varying degrees. The spectra were then analyzed by fitting each SERS spectrum as a sum of Lorentzian functions and a third-order polynomial background. This analysis is an improvement over cruder background subtraction method used for the earlier experiments that was not as accurate for spectra with low signal to noise or high background fluorescence. This study supports the conclusion that the SERS enhancement decreases with increasing molecule size when measured on Au nanospheres aggregated in situ.
EXAMPLES
[0042] The following examples are provided for illustrative purposes only and are not intended to limit the scope of the invention.
Example 1
Procedure
Reporter Molecules
[0043] The reporter molecules used in the described examples are listed in Table 1, along with abbreviations which will be used throughout the rest of this disclosure. Molecules D1, D2, D4, and P1 were purchased from Sigma Aldrich. Molecule D6 was purchased from Exciton. Other molecules were synthesized by applicant.
[0000]
TABLE 1
Reporter molecules and abbreviations
Abbreviation
Molecule
D1
4,4′-dypyridyl
D2
trans-1,2-bis(4-pyridyl)-ethylene
D3
1,2-di(4-pyridyl) acetylene
D4
4-pyridinealdazine
D5
1-(4-[4-pyridyl]phenyl)-2-(4-pyridyl)ethylene
D6
1,4-Bis-(4-pyridyl-2-ethenyl) Benzene
P1
4-phenylpyridine
P2
2-phenyl-1-(4-pyridyl)ethylene
P3
1-(4-biphenyl)-2-(4-pyridyl)ethylene
P4
(4-biphenyl)(4-pyridyl)acetylene
Normal Raman Measurements
[0044] Normal Raman measurements of the reporter molecules were made using solutions of the molecule dissolved in dimethylformamide (DMF). For the majority of the molecules the concentration was 0.1 M. For D1 the spectrum was measured at 1 M due to its low Raman cross-section. Larger molecules were measured at lower concentrations due to low solubility: P3 was measured at 0.025 M, while D6 and P4 were measured at 0.02 M.
SERS and UV-vis-NIR Measurements
[0045] All the reporter molecules used were diluted to 0.1 mM in ethanol for the SERS measurements. SERS spectra of the reporters were acquired on aggregated Au colloid and UV-vis-NIR measurements were taken between SERS measurements to monitor possible changes to the colloid aggregation between SERS measurements at different wavelengths.
[0046] The first set of experiments monitored the SERS from the two different families of molecules. The Au colloid had a diameter of 94.4±5.5 nm (as measured by TEM) and an as-made concentration of 1.17×10 10 particles/mL (0.1 g/L of Au). First, the optimal ratio of colloid to reporter volume was determined by introducing varying aliquots of the reporter solution to 1 mL of the colloid while monitoring the SERS intensity using 785-nm excitation and a 1 s integration time. If the reporter itself did not aggregate the colloid, 14 μL of 1 M NaCl was also introduced to the solution immediately after the reporter addition to induce aggregation. The SERS spectrum was monitored over time, and the maximum intensity observed was recorded. The optimal reporter volume was found to be 7 μL for each of the reporter molecules studied. This reporter to colloid ratio was used throughout the experiments.
[0047] Measurements were made by adding 10 μL of the reporter solution to 1.5 mL of as-made colloid, and vortexing the solution rapidly. If the reporter itself did not induce aggregation in the colloid, 20 μL of 1 M NaCl was added to the colloid solution immediately after the reporter addition. The SERS signal using 785-nm excitation was monitored while the sample was periodically vortexed. Once the SERS intensity reached a plateau, the solution was diluted by a factor of two. The following measurements were then made in order: UV-vis, NIR, SERS using 785-nm excitation, UV-vis, NIR, SERS using 1064-nm excitation, SERS using 633-nm excitation, UV-vis, and finally NIR. The samples were agitated with a pipette between each measurement. UV-vis and NIR measurements were made in 1 cm path length polystyrene cuvettes. The SERS measurements were made with a neat pyridine sample as a reference. A 750 μL aliquot of the colloid/reporter solution was transferred to a glass vial for SERS measurements, and then returned to the original sample and mixed before the next UV-vis and NIR measurement.
[0048] This series of absorbance and SERS measurements was completed between two and eight times for each reporter molecule, by at least two different people to ensure reproducibility. The exceptions are D5 and P4, which were somewhat unstable in solution, so that only two series of measurements made by one person were possible.
[0049] The second set of experiments involved looking for the maximum SERS enhancement factors using different excitation wavelengths and different colloid sizes. The Au colloid studied had diameters of 42.4±2.9, 59.1±3.8, 94.4±5.5, and 119.1±7.0 nm. For brevity, these colloid sizes will hereafter be referred to as 40, 60, 90, and 120 nm. Each of these colloids has an as-made Au concentration of 0.1 g/L. However, since the nanospheres are of different sizes, the particle concentrations will vary. The series of SERS and absorbance measurements were conducted as before, but this time multiple reporter volumes were used for each colloid, and the experiment was only carried out once for each reporter volume and colloid size.
Spectral Analysis
[0050] Both the normal Raman and SERS spectra were analyzed using original procedures written using Igor Pro 6.1 (Wavemetrics, Inc.). The spectra were fit to the sum of a number of Lorentzian functions with various peak heights and a third-order polynomial background (See for example the representative curve fit of FIG. 3 ). The Lorentzian functions were used to fit the observed Raman peaks, and the polynomial background accounted for any background fluorescence that may have been present. The peak locations, amplitudes, and widths were derived from this analysis.
Enhancement Calculation
[0051] To compare the SERS enhancements of different molecules, the analytical enhancement factor as presented by Le Ru, et al. was employed; Le Ru, E. C.; Blackie, E.; Meyer, M.; Etchegoin, P. G. Surface enhanced Raman scattering enhancement factors: a comprehensive study. Journal of Physical Chemistry C 2007, 111 (37), 13794-13803. Specifically, the SERS enhancement factor, EF, of a particular Raman peak is calculated by comparing the peak intensity of the normal Raman signal, I Raman , to that of the SERS signal, I SERS , using the equation
[0000]
EF
=
I
SERS
I
Raman
×
C
Raman
C
SERS
[0000] in which C Raman and C SERS are the reporter molecule concentrations used in the normal Raman and SERS measurements, respectfully. This calculation assumes that all of the reporter molecules used in the preparation of SERS samples are contributing to the SERS signal. Since the Raman spectrum of each molecule is unique, this study focuses on two peaks that are common to all of the molecules used, those near 1600 cm −1 and 1000 cm −1 .
Example 1
Results and Discussion
[0052] Enhancement vs. Molecule Size
[0053] In order to isolate the impact of molecule size on the achievable SERS enhancements, two different sets of molecules were studied. The first set of reporter molecules consists of molecules that have two terminal pyridyl groups, the “D-set”, the smallest of which is 4,4′-dypyridyl (See FIG. 4 ). By isolating this set of molecules with the same terminal groups and similar structures, the relationship between the SERS enhancement and the molecule length can be more clearly observed. In particular, the 1600 cm −1 C═C stretch and 1000 cm −1 symmetric ring breathing modes were monitored. These particular modes were chosen because they are common to all of the molecules in the D-set, clearly distinguishable from the other molecular Raman modes, and strong enough to yield good signal to noise in both normal Raman and SERS spectra. For both Raman modes, the SERS enhancement factor of the molecules in the D-set decreased as the length of the molecule increased; a trend that is consistent with that observed in earlier experiments. There is much less scatter evident in this new set of data, which is probably due to similarities between all of the molecules in this set. The enhancement factor consistently decreases with increasing molecule size within the error of the experiment. This data strongly supports the contention that SERS enhancement can be significantly influenced by the ability of a reporter molecule to access the hotspots created by SERS-active materials.
[0054] The same trend holds true for all of the excitation wavelengths studied—633, 785, and 1064 nm—further supporting the above conclusions. In order to compare data from different wavelengths, however, it is important to ensure that the data at each excitation wavelength comes from essentially the same sample. In other words, the sample should not continue to aggregate during the process of collecting the SERS and UV-vis-NIR measurements (See FIG. 5 ). The absorbance spectra taken at the beginning and the end of a series of measurements are essentially the same ( FIG. 5 , top), indicating that the state of aggregation remained relatively constant over the course of the measurements. Since the state of aggregation is the same for each SERS measurement, the geometry of the hotspots within the sample and, therefore the number of reporter molecules that can access the hotspots, should be the same as well. From sample to sample, there is greater variation evident in the absorbance spectra ( FIG. 5 , bottom), which probably causes some of the measured variation in SERS enhancement factors between samples. However, this variation is minimal, as evidenced by the small error bars in FIG. 4 .
[0055] The consistent decrease in SERS enhancement factor with increasing reporter molecule length indicates that the observed enhancement depends on the ability of the molecule to fit into crevices formed by the aggregated colloid, and not the particular molecular or plasmon resonances that may be active in the system. First of all, the wavelength independence of the trend indicates that it is not influenced by any particular molecular resonance, since such a resonance would dramatically increase the SERS signal at only one of the excitation wavelengths used, not all three studied. Since no such anomalies are observed in the data, it may be concluded that molecular resonances do not impact the results. The observed trend also does not appear to depend on the plasmon resonance of the Au nanoparticles. The three excitation wavelengths used would excite different resonances of the particles. SERS data using the 633-nm laser excitation is primarily influenced by the higher energy plasmon resonance that is associated with either single particles or the transverse mode of particle aggregates (discussed in the Simulations section below). The SERS signals from the 785 and 1064-nm laser excitation, however, are influenced by the lower energy plasmon resonance that is associated with nanoparticle aggregates. Therefore, the decrease in SERS as a function of increasing molecule size does not depend on the plasmonic properties of the nanoparticle aggregates.
[0056] One aspect of the data that may be influenced by the plasmon resonance of the nanoparticle aggregates is the magnitude of the SERS enhancement factors observed. In this experiment, samples were optimized for SERS using 785-nm laser excitation, so it is unsurprising that the highest enhancements observed from these experiments result from using 785-nm excitation. The enhancements using 1064-nm excitation are fairly comparable to those from 785-nm excitation, which may be indicative of the fact that both of these enhancements would result from enhanced near-field associated with nanoparticle aggregates. In contrast, enhancements achieved using 633-nm excitations were significantly lower. As mentioned previously, the optical properties of these aggregates at 633 nm is mostly associated with the plasmon resonance of single particles, or from the transverse plasmon resonance mode of a nanoparticle aggregates. It is possible that these resonances do not create equally high near-field enhancements, or that they are not as efficient at scattering the Raman-shifted photon to the detector, an issue which will be addressed in a following section.
[0057] Another set of molecules was also studied to confirm that this effect was not unique to the D-set. This second set of molecules, the “P-set”, consists of molecules with one terminal pyridyl group and one terminal phenyl group, the smallest of which was 4-phenylpyridine (See FIG. 6 ). As with the D-set, the SERS enhancement factors observed from this set of molecules decreases with increasing molecule size, in a much more consistent manner than observed in the original experiments utilizing a varied mix of molecule compositions. Again, the observed enhancements from all three excitation wavelengths behaved in this manner, and the enhancements using 633-nm excitation were significantly lower than those using 785 and 1064-nm excitation. This set of molecules further supports the theory that SERS enhancements observed on aggregated colloid is strongly dependent on the ability of the molecule to fit into the crevices formed by the colloid.
[0058] One interesting and unexpected feature of this data set is that the enhancement observed from P3 is comparable to that observed from P2 at every excitation wavelength, despite the fact that the P3 is 40% longer. This apparent discrepancy illustrates one aspect of why there was significantly more scatter observed in the original experiments than in these experiments. In the P-set of molecules, the smallest two, P1 and P2, required the addition of salt to induce aggregation in the Au colloid, whereas the two larger molecules, P3 and P4, did not. This difference indicates that there are different mechanisms at work inducing aggregation in these samples. This difference, in turn, affects the types of aggregates and crevices formed, which may change the near-field enhancement produced in the hotspots and the ability of the molecules to access those hot spots. For the P-set, this effect seems to have resulted in a smaller decrease than expected between the molecules where the transition between aggregation mechanisms occurs. Since the molecules are still fairly similar, this effect did not seem to drastically affect the overall trend. In contrast, the varied molecules used in the original experiments probably interacted in very different ways with the Au colloid, resulting in the variability to the observed trend.
[0000] Enhancement Vs. Colloid Size
[0059] To probe this system further, the crevices formed by the aggregated Au colloid were changed in a controlled manner. One way to accomplish this is to use different sizes of colloid. The larger radius of curvature for larger colloid would result in deeper and sharper crevices formed between the particles. As illustrated in FIG. 7 , the larger the colloid, the further away the molecules are situated. Also, the difference in distance from the junction between the smallest molecule (D1) and largest molecule (D6) in this study is greater for the larger colloid than the smaller colloid. So, to investigate the impact of the crevice geometry on the SERS enhancements achieved, four colloid sizes were investigated: 40, 60, 90, and 120 nm colloid. The maximal SERS enhancements achieved using a number of molecules (D1, D2, D3, D4, D5 and D6) in the D-set were obtained.
[0060] As FIG. 8 shows, very little difference was observed in the SERS enhancements arising from aggregates of the 4 different colloid sizes studied. On average, the different colloid sizes resulted in ˜30% variation in the SERS signals observed at each wavelength for each molecule. This variation was, for the most part, not systematic; no colloid size consistently yielded the greatest or the least SERS enhancements using 633 nm excitation. SERS enhancements using 785-nm excitation were always greatest using 90-nm colloid, although the SERS enhancements from the other colloid did not fall into any particular pattern. However, the enhancements observed using 1064-nm excitation did yield a consistent pattern. 60-nm colloid almost always yielded the brightest enhancements using 1064-nm excitation, followed by 90-nm, 40-nm, and then 120-nm colloid. It may be that the data using 1064-nm excitation is more systematic because the excitation and Raman scattered wavelengths are only influenced by the plasmon resonance of the nanoparticle aggregates. In contrast, the single particle plasmon resonance will influence 633 and (to a lesser extent) 785-nm excitation, which may contribute to the observed SERS signals in a variety of ways.
[0061] When different samples were fabricated to maximize the SERS enhancements observed at each of the three wavelengths studied, the greatest enhancements observed on each colloid size consistently came from D1 using 1064-nm excitation. For the other molecules, the enhancements observed using 785 and 1064-nm were comparable, as was observed in the previous experiments. Also, 633-nm excitation again yielded significantly weaker enhancements than the other two wavelengths.
[0062] One interesting feature of the data collected is that for each colloid size, the rate at which the SERS enhancement decreases as a function of colloid size is approximately equal for each excitation wavelength used. The slopes of the linear fits shown in FIG. 8 (right) differ by only ˜6%. This fact may again support the theory that the data is mainly a result of geometric considerations, and not plasmonic ones.
Finite Element Simulations of Electromagnetic Properties
[0063] Electromagetic simulations were performed using COMSOL Multiphysics 3.4 to develop a deeper understanding of electromagnetic near-field enhancements created by the crevices in aggregated Au nanoparticles of different sizes. COMSOL uses the finite element method to calculate the optical properties of a nanoparticle. This tool splits user-defined, finite simulation geometry into many discrete elements, and solves Maxwell's equations in the simulation volume using the dielectric function of the materials within and the boundary conditions applicable to the interfaces between the constituent materials. It is particularly useful for calculating the optical properties of particles of arbitrary shape for which analytical solutions (like Mie Scattering Theory) do not exist.
[0064] In the described experiments, calculations were focused on the optical properties of Au dimers. It has been shown that nanoparticle dimers generally exhibit near-field enhancements orders of magnitude greater than single particles, so it is reasonable to assume that most of the SERS intensity observed arises from nanoparticle aggregates. Although previous experience has shown that samples created by aggregating Au colloid contain a wide distribution in the types and sizes of aggregates formed, Au nanoparticle dimers were studied to reduce computational complexity. Previous electron microscopy data also suggests that the aggregates in the samples consist of nanoparticles which are touching. Since experimentally fabricated colloid is not perfectly spherical, the nanoparticles are in contact over some finite area (i.e. not at a single point). As such, the contact area of each dimer is modeled by a small overlap in the constituent nanospheres—the smaller the overlap, the smaller the contact area. The simulations of FIG. 9 demonstrates that the broad plasmon peak in the near-IR that was evident in UV-vis measurements (see FIG. 5 ) can be attributed to aggregates in the solution, whereas the plasmon resonance centered about 600 nm contains contributions from both single particles and aggregates. The broadness in the aggregate peak could be a result of the variation in the contact area in each aggregate and/or the range in the number of nanoparticles present in each aggregate. The simulations show that the longitudinal plasmon, which is excited when incident light is polarized along the axis of the dimer particle, is very sensitive to the overlap of the two nanoparticles in the dimer, a feature which has been demonstrated previously with core-shell nanoparticles.
[0065] Since the calculated extinction spectra of overlapping dimers are comparable to experimental results, the same simulations were used to understand the near-field enhancements experienced by molecules situated in the crevices. It was assumed that the molecules that are experiencing the greatest near-field enhancement are situated parallel to the dimer axis, and are bound to each nanoparticle in the dimer at either end of the molecules, as depicted in FIG. 7 . Making this assumption, the expected electromagnetic Raman enhancement of the 1600 cm −1 peak at the center of the molecule may be calculated as a function of molecule length for the 4 different sizes of colloid considered ( FIG. 10 ). To compare the results from the different sizes of colloid, the relative geometry was kept constant by setting the overlap in each case to be D=rcolloid/15. This overlap was chosen to approximate the location of the aggregate peak in the experimental UV-vis spectra well. The electromagnetic Raman enhancement was calculated as E 2 laser ×E 2 Raman where E laser and E Raman are the near-field enhancements at the laser and Raman shifted wavelengths, respectively. Small kinks in the calculated trends occur at the boundaries between mesh elements in the simulation.
[0066] Qualitatively, simulations agree with the experimental data: the enhancement drops off as a function of molecule length and the rate at which it decreases is comparable for all colloid sizes and excitation wavelengths. The simulations also show that the rate of the enhancement decrease is roughly the same for all of the colloid sizes, excitation wavelengths, and Raman peaks examined. Although geometric factors contribute to a molecule's ability to fit into the crevice created by aggregated colloid of different sizes, the SERS enhancement also depends on the nature of the near-field enhancement created at the crevice.
[0067] Dimers that consist of larger colloids create near-fields that extend further away from the dimer junction at the wavelengths of interest. Thus, although a large molecule may have difficulty getting very far within the crevice created by a 120 nm Au colloid dimer, the near-field it experiences is still significantly enhanced since that near-field extends farther away from the dimer junction.
[0068] One interesting aspect of the described simulations that is not consistent with experimental results is that the SERS enhancement using 633-nm excitation is calculated to be much greater than that observed with 785 and 1064-nm excitation. In experiments, the enhancement using 633-nm excitation is significantly lower. One possible explanation for these results is that the optical properties of the sample are blocking the SERS scattered light, either through absorption or multiple scattering events that tend to scatter the light away from the detector in the measurement geometry used. More detailed studies of the absorption and angle-dependent scattering of aggregates would be required to develop further understanding of this issue.
Example 1
Conclusion
[0069] The impact of reporter molecule size on SERS enhancements has been studied using aggregated Au colloid. By studying sets of reporter molecules with similar structure and identical terminal functional groups, the experiments with each molecule can be more readily compared, since parameters such as the mechanism of aggregation, reporter orientation, and reporter affinity will be fairly consistent within the set. Experiments with two sets of reporter molecules, three excitation wavelengths, and four Au colloid sizes all demonstrated that the SERS enhancement factor achieved decreased with reporter molecule size. The consistency of the trends with variation in each of these parameters supports the conclusion that the effect is based on the molecule size, not particular plasmon or molecular resonances. Electromagnetic simulations of Au dimers indicate that these results are consistent with the decrease in the electromagnetic near-field created in the crevices between the Au colloids as the distance from the particle junction increases. These results demonstrate that molecule size is a critical parameter to be considered when designing a system to generate the highest possible SERS enhancements.
Example 2
Introduction
[0070] As described above, one way of increasing the strength of a SERS signal from any SERS system is to use reporter molecules with very high SERS activity. Many potential reporter molecules have been screened, and certain conclusions about the structure/activity relationship have been made, including but not limited to:
[0071] a) A reporter molecule with high SERS activity may have at least one aromatic ring conjugated with one or more unsaturated groups. This extended conjugated system increases the Raman cross-section of the molecule.
[0072] b) A reporter molecule with high SERS activity may have a functional group capable of forming a stable bond with the gold surface, in a way that it positions the molecule in an orientation that is perpendicular to the surface. The best and more consistent binding groups are pyridyl, monosubstituted ethynyl, and in a lesser extent, thiol groups. Thiol groups, although capable of forming strong bonds with gold, appear to react very slowly.
[0073] c) In general, the presence of a second binding functional group in the opposite end of the molecule results in larger enhancement.
Solution Raman Spectra
[0074] Experiments were performed as described herein to determine if the Raman cross-sections of a set of molecules correlate with the corresponding extension of the conjugated system of those molecules. FIG. 11 shows the set of molecules chosen for this aspect of the study. The chosen reporter molecules range in size from a single aromatic ring (pyridine) to a molecule that contains three aromatic rings bridged by ethylenic groups and having also an alkynyl and 2 cyano groups, all groups conjugated (molecule F). The molecules were chosen to have pyridyl and/or ethynyl groups to bind to the gold surface, while belonging to the same structural family of compounds. A reporter was included in which one of the rings is forced out of the plane by the presence of two Br substituents in a pyridyl ring (molecule A) to explore the effect of decreased conjugation, and another molecule was included without a metal binding functional group in one of its ends. Pyridine, 4-mercaptopyridine (4-MP) and BPE were purchased from Sigma-Aldrich. Bis-(2-pyrid-4-ylethenyl)benzene (S-BPE) was purchased from Exciton. The rest of the molecules were prepared in house, by Knovenagel condensation between 4-ethynylphenyl acetonitrile and the corresponding aldehyde. Molecule C was synthesized by the condensation of 4-pyridylacetonitrile and 4-ethynylphenylbenzaldehyde (See FIG. 12 ).
[0075] FIG. 11 also shows the corresponding approximate size of each of the molecules, calculated with ArgusLab, a software that utilizes semiempirical methods for geometry optimizations.
[0076] The Raman spectra of this experiment were obtained from 0.1 M solutions of the reporter in DMF, using pure DMF as the reference (all the Raman and SERS readings were carried out using an Ocean Optics QE6500 785 nm spectrometer). The exceptions were pyridine and 4-mercaptopyridine, which due to sensitivity limitations were obtained with a 1 M solution, and S-BPE and molecule F, which because of limited solubility were performed with a 0.02 and 0.01 M solution respectively. All readings were later corrected for concentration. The Raman intensity results are plotted in FIG. 13 .
[0077] It can be seen from the graph of FIG. 13 that the relative Raman intensities follow the expected trend. The Raman signal increases with the size of the conjugated path in the molecule. The main exception is molecule A. The lower Raman intensity of this molecule compared to others of similar size is likely due to the effect that the presence of the two Br groups has on the planarity of the molecule. The intensities of the Raman spectra of the four largest molecules are very high, and large increases take place with small changes in the size of the molecules. This clearly indicates that the Raman cross-sections of the reporters increase with the extension and efficiency of the conjugated system.
Colloid SERS Experiments
[0078] Colloid SERS experiments were carried out as follows: 7 ul of 0.1 mM solution of the reporter molecule (except pyridine, vide infra) is added to a vial containing 1 mL of 90 nm gold colloid (2× concentration) and the vial is immediately shaken (It having been determined as described above that this amount of reporter gives the maximum SERS possible, except for pyridine. In this case, because of the high solubility of pyridine in water, it is likely that only a small fraction of it binds to the gold surface, resulting in the need to add more reporter: 20 ul of a 1 mM solution. Since this amount results in the highest SERS possible, it is estimated that the amount of pyridine molecules attached to the gold is comparable to the other reporters, which is relevant when calculating the enhancement factors). If aggregation takes place, SERS is read continuously with 1 sec integration until the highest SERS is obtained. The spectrum is then saved. If no aggregation takes place, 20 ul of NaCl 1 M is added to induce aggregation followed by SERS reading. Of this group of compounds, pyridine and molecules A, B and D needed the addition of NaCl to induce aggregation. Shorter integration times were needed for compounds C, E and F because the signals for these reporter molecules went out of scale when irradiated for 1 sec. The SERS intensities of the molecules requiring shorter integration times were corrected afterwards accordingly. The graph in FIG. 14 shows the height of the tallest peak of the SERS spectrum for each of the reporters.
[0079] It can be observed in the FIG. 14 graph that SERS intensity increases from pyridine to BPE, and dramatically to molecule C. The SERS intensity is lower for molecule A, which is in line with the result obtained for the solution Raman spectrum. The low SERS of molecule B is of no surprise since it has been previously observed that the lack of a metal binding group in one of the molecular ends usually results in lower SERS activity than expected. Contrary to the solution Raman experiments, the SERS intensities for the largest molecules are much lower than molecule C, and the increase of SERS due to molecular size seems to come to a halt. It is clear that the surface Raman enhancement for larger molecules does not correlate with higher cross-section. To better understand this behavior, SERS experiments using a commercial SERS substrate, Klarite™ were performed.
Substrate SERS Experiments
[0080] Experiments on Klarite substrates were performed to determine the reasons for the low colloid SERS response obtained with the largest reporters. Klarite substrates are nano-engineered gold chips that provide the necessary roughened surface for SERS enhancement.
[0081] SEM images of the substrates were obtained as shown in FIG. 15 . The surface appears to consist of pyramidal features of around 1.5 microns carved into the gold surface. The sides of these features are covered with irregular granules 30-40 nm in size. The rough surface formed by these granules is likely responsible for the SERS enhancement activity. It is important to note that the main difference between these substrates and the gold colloids discussed above is that with the substrates the addition of reporter molecules should not induce any change in the structure of the surfaces, while the addition of reporter to a colloid usually induces aggregation. This induced contact between particles is the responsible for the high SERS enhancements.
[0082] The experiments were run as follows: An adhesive rubber gasket containing a hole of around 2 mm across and 3 mm deep is adhered to the gold substrate. The resulting cavity can hold ˜10 ul of a liquid. 10 ul of a 10 mM solution of the reporter in 1/9 DMF/EtOH is added to the cavity and left there for 1 minute. Then the solution is pipetted off, and the surface is rinsed with 10 ul of EtOH. The ethanol is discarded and the SERS is read on the 785 nm spectrometer. The spectrum is recorded, and the substrate is treated again with 10 mM reporter solution and rinsed as mentioned above. SERS is read again. The process is repeated until no more increase in SERS takes place. It typically takes 3 to 5 applications to get to constant SERS. Pyridine did not show any SERS, while molecule F had to be performed with a 1 mM solution due to solubility limitations. The described method was designed to assure saturation of the surface with the reporter molecule. To assure that no signal is due to the Raman spectrum of solid formed on the surface (non-SERS) a few control experiments were done on the smooth part of the gold chip, resulting in negligible Raman signal.
[0083] The scattering intensity results of the substrate SERS experiments are shown in FIG. 16 .
[0084] Two clear observations may be made from the results illustrated in FIG. 16 . (a) The use of gold colloid results in much higher surface Raman enhancement than the substrate; and (b) the SERS signal in the substrate increases with the size of the molecule. In the case of molecule A the SERS signal is not as strong as observed for similar sized molecules due to the decrease of molecular planarity, and except for the difference between molecules B and C (which have comparable molecular size), the relative SERS intensities of the whole series fall in the expected order. Here again the higher intensity for molecule B than BPE is observed. Reporter F was the highest even when though a lower concentration solution for the experiment was used. It is also evident that the increase of the signal is not proportional to the increase of the solution Raman intensities. It is believed that the molecules stand perpendicular to the surface, and that the increase of the distance from the farthest end of the molecule to the gold surface results in a lower exposure of that side of the molecule to the enhanced electromagnetic field. Based upon the foregoing observation, it may be estimated that even longer conjugated molecules would not result in important increases in SERS activity and that at some point the SERS intensity should reach a plateau.
[0085] The results obtained from the gold substrate experiments suggest that the larger reporters have the potential to give higher SERS response. Thus, there must be other factors affecting the SERS activity of these same molecules when used with gold colloids. As described above, most of the colloid SERS signal is generated in hot spots present in the join area between two particles that have aggregated. It is possible that the reporter molecule positions itself between the particles, acting as a bridge between them. For larger molecules this means that the two particles must stay further from each other. The larger separation of the particles results in lower electromagnetic enhancement, hence producing lower SERS signal.
[0086] A more likely theory is that when two particles aggregate the particles basically become fused, and the reporter molecule positions itself in the tiny crevice formed next to the particle-to-particle contact area. Theoretical calculations show that the electromagnetic field is very strong in this area, but it quickly decreases as the distance to the contact area becomes longer (and the gap between the particles becomes larger). This suggests, as described in detail above and schematically illustrated in FIG. 17 , that smaller molecules will be able to penetrate deeper in this crevice and show larger enhancement, while larger molecules will be forced to stay further outside, where the molecule can maintain a vertical orientation while bridging the two particles. As a result, the high Raman cross-section of a longer molecule will be offset by the lower EM field to which it is exposed due to its placement further out in the crevice. If this is the case, it would be expected that a higher enhancement factor would be observed for smaller molecules like pyridine, and a poorer factor for large molecules such as molecule F.
[0087] It is important to remember that the Klarite substrates also have nano-sized granules that may be in contact with each other. Substrate fabrication methods (probably vapor deposition) may result however in different geometries without the type of crevices that are found in aggregated colloid. Thus, the substrate would be expected to result in similar electromagnetic enhancement for every reporter regardless of its size.
[0088] The enhancement factors for the colloid SERS experiments of all the molecules in the series were calculated, and the results are shown in FIG. 18 . The enhancement factor was calculated by using the following formula:
[0000] E=[S ( C r /C s )]/ R
[0000] in which E is the enhancement factor, S the colloid SERS intensity, R the solution Raman intensity, and C r and C s are the concentrations of the reporter in the Raman and SERS samples respectively. The enhancement factor is the highest for the smallest molecules, pyridine and 4-mercaptopyridine, and except for C, the enhancement factor quickly goes down for larger molecules. These results are in line with the theory described above. The decrease of enhancement with the size of the molecule presents a challenge to the search for bright reporter molecules and suggests that the most efficient way to prepare highly bright tags is by using resonant reporters. This last option is a valid one, but resonant reporters are usually large, more complex molecules that result in too many bands and high backgrounds, something that may not be convenient when a few discrete peaks are what it is desired.
Example 2
Conclusions
[0089] The side by side comparison of data from Raman solution, colloid SERS and substrate SERS reveals that the lower than expected SERS brightness of the larger conjugated molecules may not be related to intrinsic properties of the molecules. Instead, the geometry of the aggregated particles puts constrains to these molecules to access areas of higher EM energy. This clearly sets limitations to the search for brighter reporters because higher Raman cross-sections of longer conjugated systems will be offset by the lower enhancement.
[0090] The lower SERS of molecule A is explained by the deviation of planarity of the pyridine ring. On the other hand, the low colloid SERS and higher substrate SERS of B may be due to the lack of bridging capability between particles, resulting in an unfavorable position and/or orientation of the reporter for efficient enhancement.
General Conclusions
[0091] It may be concluded from the molecular-size/SERS-enhancement studies described above that the shorter the reporter molecule, the higher the SERS enhancement is when the molecule is added to gold colloid. On the contrary, as demonstrated in the Solution Raman spectra experiments, longer molecules, i.e. molecules having a larger conjugated path have a larger Raman cross section and therefore exhibit greater Raman signal intensity in solution. When these two separate effects are combined in a colloid system an offset is seen to occur. In particular, the enhancement of SERS signal of generally greater for smaller reporter molecules as described above, but this is partially offset because small molecules have low Raman cross-section. Thus, SERS intensity as a function of reporter molecule length actually increases with the size of the molecule up to a size of ˜1.2 nm, when the reporter is adsorbed to the surface of nano-scale enhancing colloids. Reporter molecules that are longer have a higher Raman cross-section, but their SERS enhancement decreases considerably, resulting in a lower SERS intensity. Accordingly, reporter molecules with 2 or more metal binding groups that are no more than 1.2 nm apart, but with higher conjugated systems would have much higher SERS brightness. This increased conjugation would arise from an extended conjugated path towards the sides of the molecule. Some examples are illustrated below. The larger molecular surface of this type of reporters may result in an increased tendency to adsorb flat to the metal surface. For this reason, the presence of more binding groups would be favorable for both, a stand up binding position and better binding stability to the metal surface.
[0092] A list of molecules with these characteristics and which should exhibit exceptional SERS brightness includes, but is not limited to, 1,8-diethynyl-4,5-bis(4-pyridylethenyl)anthracene, 1,8,9-triethynyl-10-(4-pyridylethenyl)anthracene, 6,13-bisethynylpentacene, 5,7,12,14-tetraethynylpentacene, 9,10-bisethynylanthracene, 1,4,5,8,9,10-hexaethynylanthracene, 1,8-bisethynylanthracene, 9-ethynyl-10-(4-pyridylethynyl)anthracene, 1,8,9-tris(4-pyridyl)anthracene, 1,8-bis(4-pyridyl)-10-(4-pyridylethynyl)anthracene, 1,8-bis(4-pyridyl)-10-ethynylanthracene, 1,8-bis-(4-pyridyl)-10-(4-pyridylazo)anthracene, and 1,8-diethynyl-10-(4-pyridylazo)anthracene.
[0000]
[0093] Various embodiments of the disclosure could also include permutations of the various elements recited in the claims as if each dependent claim was a multiple dependent claim incorporating the limitations of each of the preceding dependent claims as well as the independent claims. Such permutations are expressly within the scope of this disclosure.
[0094] While the embodiments disclosed herein have been particularly shown and described with reference to a number of examples, it would be understood by those skilled in the art that changes in the form and details may be made to the various embodiments disclosed herein without departing from the spirit and scope of the disclosure and that the various embodiments disclosed herein are not intended to act as limitations on the scope of the claims.
[0095] All references sited herein are incorporated in their entirety by reference for all matters disclosed therein.
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A SERS tag comprising a core comprising at least two aggregated particles of a SERS enhancing material wherein the contact point between the particles defines a crevice; and a reporter molecule having a length sufficiently short to fit into the crevice and a conjugated path length which is as large as possible, provided the overall reporter molecule length is maintained sufficiently short to fit into the crevice.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention concerns systems useful in earth wells. This invention more specifically concerns well injection systems useful for injecting fluids in a formation encountered by an earth well bore.
2. Background Art
Various systems have been used in earth wells to pump fluids down well flow conduits for "injection" into a formation. The fluids, either liquid or gas, are usually required in larger volumes for Enhanced Oil Recovery operations, such as water, steam and CO 2 injection into selected wells in a formation to "flood" the formation or reservoir to ultimately cause recovery of greater quantities of hydrocarbons from the formation than if usual recovery methods were used.
U.S. Pat. No. 4,355,686 to Henry P. Arendt and Thomas J. Heard discloses a method of operating an injection well and apparatus used in the well. This patent teaches injection through a well flow conduit into a formation after a plug is expended from the conduit, but suggests no way of controlling injected flow rates.
SUMMARY
Both injection systems of the present invention will permit large quantity fluid injection into a formation with control of injected flow rates by multiple orifices. The orifices are housed in injection mandrels, which may be retrieved from cooperating landing nipples in the well flow conduit and orifice sizes changed for any required changes in injection rates. The landing nipples are included in well flow conduits and more than one nipple may be used in a conduit. Each landing nipple is installed in the well in sealed communication with a formation by setting packers in the well casing. Fluids to be injected in formations are pumped down the flow conduit, into and through the injection mandrel orifices, through openings for flow in the nipple walls, the tubing-casing annulus, casing perforations and into the formation.
Each injection mandrel includes a lock mandrel, openings for flow through the mandrel walls, an orifice in each opening and an orientor. The lock mandrels used are of the type usually lowered into a well conduit on wireline to land, seal and be releasably locked in a "no-go" landing nipple in the well conduit or caused to "select" a particular landing nipple from a number of identical landing nipples in a well conduit to seal and be releasably locked in. Both landing nipples have openings for flow through the nipple walls and orientors which engage the injection mandrel orientors to orient and align the injection mandrel and nipple flow openings when the injection mandrel is lowered into the nipple.
The no-go landing nipple has an internal profile in which a no-go type lock mandrel may seal and be releasably locked and orienting pins which engage orienting slots between flow openings on the no-go injection mandrel orientor.
The selective landing nipple has an internal profile in which a selective type lock mandrel may seal and be releasably locked and an internal orienting sleeve. This sleeve has openings and slots whose sides are camming surfaces which are engaged by lugs on the selective injection mandrel orientor as it is lowered into the selected nipple. The lugs, orientor and mandrel are rotated by the camming surfaces, aligning the openings for flow in the mandrel and nipple when the selective lock has sealed and landed in the nipple profile.
Each orienting lug in the selective mandrel orientor has a lower "lead-in" and an upper "lead-out" tapered surface on its outer surface. The lugs are slidably mounted for inward and outward movement in holes in the orientor mandrel and are biased outwardly. There is a camming surface in each nipple sleeve slot bottom which contacts the lug lead-in surface and cams the lug inwardly permitting the orientor and injection mandrel to be lowered through a selective landing nipple. Each lug also has side flat surfaces which engage the internal orienting sleeve opening and slot side camming surfaces when the mandrel is lowered into a selective nipple to turn the mandrel and align the orifices with flow openings in the nipple.
It should be apparent to all skilled in well injection and production art, that the injection systems disclosed in this application could also be used as production systems with the mandrel orifices controlling production rate or flow from a well formation upwardly to surface in a well conduit.
An object of this invention is to provide well injection systems through which large quantities of fluid may be injected.
Also an object of this invention is to provide well injection systems having means for controlling the rate of the large quantities injected.
Another object of this invention is to provide injection systems utilizing both no-go and selective locking systems.
Also an object of this invention is to provide an injection mandrel useful with a selective locking system, which may be lowered through a nipple and locked in a lower nipple in the well conduit.
Another object of this invention is to provide injection systems having injection mandrels with orientors which orient and align openings for injection flow when lowered into a landing nipple in the well conduit.
Also an object of this invention is to provide an orientor attachable to a well tool which will orient and align the tool when lowered into a landing nipple in the well conduit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectioned schematic drawing of a well utilizing the injection systems of this invention.
FIGS. 2A and 2B is a partially sectioned drawing of an injection mandrel of this invention locked in a no-go type landing nipple.
FIG. 3 is a cross section drawing of the nipple and mandrel of FIGS. 2A and 2B on line 3--3 of FIG. 2B and viewed as indicated.
FIGS. 4A and 4B is a partially sectioned drawing of an injection mandrel of this invention locked in a selective type landing nipple.
FIG. 5 is a half sectioned drawing of an orientor of this invention.
FIG. 6 is a drawing in section of a landing nipple engageable by the orientor of FIG. 5.
FIG. 7 is an isometric drawing of an orienting lug useful in the orientor of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an earth well 10 having a casing 11, with perforations 11a, in the bored hole which passes through a formation 12. A landing nipple 14 having wall openings 14a and a packer 15 have been made up in a flow conduit 16 and lowered into the well. The packer has been operated to grip and seal to the inside of the casing. Fluids to be injected into the formation are introduced into the flow conduit on the surface and pumped down the conduit, out through nipple openings 14a, through perforations 11a and into formation 12.
The landing nipple in the flow conduit may be a no-go type, 17 shown in FIGS. 2A and 2B or a selective type 18, shown in FIGS. 4A and 4B. An injection mandrel 19 is shown oriented, sealing and locked in nipple 17 in FIGS. 2A and 2B. An injection mandrel 20 is shown oriented, sealing and locked in nipple 18 in FIGS. 4A and 4B.
The no-go landing nipple 17 has an upper section 17a which is internally profiled as a no-go type X® landing nipple (X is a registered trademark of Otis Engineering Corp.) This upper section has an appropriate thread 21 for connection into the flow conduit, internal grooving 22 having a particular profile, a seal bore 23 and a bore 24 smaller than bore 23 providing a no-go shoulder 25 between bores 23 and 24. Threads 26 connect upper nipple section 17a to lower nipple section 17b and resilient seal 27 seals section 17a in 17b. The lower nipple section has a number of pins 17c protruding into overbore 24a to a diameter less than bore 24, a number of slots or wall openings 17d, (see also FIG. 3), a lower bore 28 for seals and an appropriate lower connecting thread 29.
The injection mandrel 19 includes an X® no-go type lock mandrel 30 which has a fishing neck 30a, engageable by X® running tools and pulling tools, keys 30b profiled to engage grooving 22, a seal system 30c sealingly engageable in seal bore 23 and a no-go shoulder 30d, which lands on nipple shoulder 25.
Connected to the lower end of the lock mandrel by thread 31 and sealed with resilient seal 32, is an orifice mandrel 33. As shown best by FIG. 3, the orifice mandrel has wall holes 33a; each of these holes has two counterbores. Groove 33b is in the smaller counterbore and groove 33c is in the larger. A flow restrictor or orifice 34 has been installed in the smaller counterbore in each hole 33a and is sealed to mandrel 33 with resilient seal 35 and retained therein with retaining ring 36 positioned in groove 33c. Orifice mandrel 33 also has aligning slots 33d and camming surfaces 33e connecting the slots. A seal system 37 on the mandrel sealingly engages the mandrel and bore 28 in the landing nipple. A cap 38, housing a closed equalizing valve 39, is connected to the lower end of the mandrel with thread 40 and is sealed to the mandrel with resilient seal 41. The equalizing valve has a slidable valve member 39a and resilient seals 39b. Cap 38 has a number of wall openings through which flow may occur between the interior of the mandrel 42 and the annulus 43 when the equalizing valve is moved downwardly until upper resilient seal 39b is below openings 38a.
The landing nipple 18, shown in FIGS. 4A and 4B, has an upper internal selective type X® profile and an appropriate thread 44 for connection in a flow conduit. Below the grooving 45 is a seal bore 46. This selective landing nipple also has a number of slots or wall flow openings 47 and a seal bore 48. Positioned in lower bore 18a of nipple 18 is an orienting sleeve 49, which is welded to the nipple at 50. This sleeve has a number of aligning slots 49a, camming surfaces 49b between the slots and inward camming surfaces 49c in the lower end of the slots. On the lower end of nipple 18 is an appropriate thread 51 for connecting this nipple in a flow conduit.
A selective type injection mandrel 20 is shown installed in nipple 18 in FIGS. 4A and 4B. This injection mandrel includes an X® selective type lock mandrel 52, which has an internal fishing neck 52a engageable by X® running tools and pulling tools, keys 52b engaging grooving 45 and a seal system 52c, which is sealingly engaged in nipple seal bore 46. Connected to the lower end of lock mandrel 52 is an orifice mandrel 53 which has wall holes 53a. Each of these holes has two counterbores; groove 53b is in the smaller counterbore and groove 53c is in the larger. A flow restrictor or orifice 34 has been installed in the small counterbore in each hole 53a and is sealed to the mandrel 53 with a resilient seal 35 and retained therein with a retaining ring 36 as the orifices 34 are in mandrel 33 shown in FIG. 3.
Returning to FIG. 4B, a seal system 54 seals on the mandrel and sealingly engages nipple bore 48. Connected to the lower end of mandrel 53 by threads 55 is an orienting mandrel 56. This orienting mandrel is closed at its lower end and has a number of upper openings 56a and lower openings 56b. Positioned by the upper openings are springs 57 and mounted for radial movement in the lower openings are orienting lugs 58. Upper and lower resilient seals 59 have been installed in grooves in orifice mandrel 56 to seal a sleeve 60 in the mandrel. The sleeve biases springs 57 and orienting lugs 58 outwardly. The interior of injection mandrel 20 is denoted by numeral 61.
As may be seen in FIG. 7, each orienting lug has a slot 58a into which spring 57 protrudes and ears 58b, which prevent the lugs from being pushed out of openings 56b. Each lug also has a radial outer surface 58c, a chamfered lead-in surface 58d and a chamfered lead-out surface 58e. These lead-in and lead-out surfaces cam the lugs inwardly to permit passage through restrictions and sliding by any square shoulders encountered in the flow conduit while the selective injection mandrel 18 is being lowered or raised from an engageable nipple in the flow conduit. When it is desirable to lower a selective injection mandrel through a selective type landing nipple, slot end camming surface 49c contacts orienting lug lead-in surfaces 58d and cams the lugs inwardly for passage of the injection mandrel downwardly through the nipple 18. Each lug 58 also has flat camming surfaces 58f and 58g.
FIG. 5 is a drawing of an orientor 62 which attaches to any well tool which requires orienting in a well flow conduit. FIG. 6 is a drawing of an orienting nipple 63, which may be engaged by orientor 62 and is connected in the well flow conductor.
The orientor has an appropriate thread 64 for connection to the well tool in the upper end packing mandrel 65. Another seal system 54 seals around the mandrel and is sealingly engageable in seal bore 63a in orienting nipple 63. An orienting mandrel 66 is connected to the packing mandrel by thread 67 and is sealed to it by resilient seal 68. Orienting mandrel 66 is the same as orienting mandrel 56 except mandrel 66 has an open lower end permitting longitudinal flow in passage 69 through orientor 62. Nipple 63 includes an upper thread 70 and a lower thread 71 for connection in a flow conduit.
Mandrel 66 (as mandrel 56) has upper and lower openings 66a and 66b. Positioned in 66a are more springs 57 and mounted for radial movement in openings 66b are orienting lugs 58. Resilient seals 59 seal sleeve 60 in the mandrel and this sleeve biases springs 57 and lugs 58 outwardly.
Landing nipple 63 has an orienting sleeve 49 positioned in nipple bore 63a and welded to the nipple at 50. Sleeve 49 has aligning slots 49a, camming surfaces 49b and inward camming surfaces 49c in the lower slot ends.
To use the no-go injection mandrel and nipple of FIGS. 2A and 2B in the system of FIG. 1, no-go nipple 17 would be used as the nipple 14 in the flow conduit 16 of FIG. 1. Orifices 34, sized to permit desired injection rates, are selected and installed in no-go injection mandrel 19. A particular system may not require equalizing valve 39 and cap 38 on the lower end of the injection mandrel. The lower end may be closed as is orienting mandrel 56 of FIG. 4B or open for flow as is orienting mandrel 66 in FIG. 5. The injection mandrel is attached to a running tool and lowered in conduit 16 and into nipple 17 until aligning slots 33d in the orientor mandrel move down in nipple pins 17c or more probably, camming surfaces 33e contact nipple pins 17c. On further downward movement of injection mandrel 19, camming surfaces 33e sliding on pins 17c rotate the injection mandrel until the slots may move down in the pins, seal system 37 moves into seal bore 28, seal system 30C moves into seal bore 23 and orifices 34 are aligned with nipple wall openings 17d. Downward movement of the injection mandrel stops when lock mandrel no-go 30d contacts nipple shoulder 25. Lock mandrel keys 30b are now opposite grooving 22 and the lock mandrel may be operated to lock the keys and injection mandrel 19 in landing nipple 17.
Fluids to be injected into the formation may now be introduced into the flow conduit at surface and be pumped down into the interior 42 of injection 19 to flow out through orifices 34, nipple wall openings 17d, through perforations 11a and into formation 12. Those skilled in well production art will recognize the injection system just described could as well be utilized as a production system with large production outflow rates controlled by orifices 34.
When it is necessary to retrieve injection mandrel 19 to surface for changing orifice sizes and injected flow rate or for maintenance, a pulling tool engageable with lock mandrel fish neck 30a and carrying a prong which will open equalizing valve 39, is lowered into the mandrel, opening the equalizing valve and engaging the fish neck to permit lock mandrel 30 to be unlocked from nipple 17 and injection mandrel 19 to be raised back to surface.
To use the selective injection mandrel and nipple of FIGS. 4A and 4B in the system of FIG. 1, selective nipple 18 would be used as the nipple 14 in the flow conduit 16 of FIG. 1. Orifices 34, sized to permit desired injection (or production) rates, are selected and installed in selective injection mandrel 20 on surface. This injection mandrel is attached to an appropriate running tool and lowered in conduit 16 and into nipple 18 until orienting lugs 58 more down in sleeve slots 49a or most likely, lug surfaces 58f or 58g will contact sleeve camming surfaces 49b. On further movement down of injection mandrel 20, orienting surfaces 58f or 58g sliding down surfaces 49b rotate the injection mandrel until lugs 58 move down in 49a, seal system 54 moves into seal bore 48, seal system 30c moves into seal bore 46 and orifices 34 are aligned with nipple wall flow openings 47. Downward movement of the injection mandrel stops when selective lock keys 52b land in nipple grooving 45. Lock mandrel 52 is operated to lock the keys in grooving 45 and injection mandrel 20 in selective landing nipple 18. If it desired to not lock the selective injection mandrel in an upper nipple, it may be lowered through the selective nipple and locked in any compatible nipple below as nipple camming surfaces 49c cam lugs 58 inwardly to permit the mandrel to pass through the nipple.
Fluids to be injected into the well formation may now be pumped down the flow conduit into the interior 61 of injection mandrel 20, out through orifices 34 and nipple wall openings 47, through perforations 11a and into formation 12. Again, those skilled in well production art will recognize the selective injection system could just as well be utilized as a production system with production flow rate to surface controlled by orifices 34. Equalizing valve 39 with cap 38 may be attached to the lower end of orifice mandrel 56 or the lower end may be left open as the system requires. Selective injection mandrel 20 may be retrieved to surface using methods previously described for no-go mandrel 19.
To use the orientor 62 of FIG. 5 in the orienting landing nipple 63 of FIG. 6, the nipple should be connected into the flow conduit and lowered into the well. The orientor is connected to the tool requiring orientation and lowered down the flow conduit and into the nipple. Lugs 58 slide down into positioning slots 49a or lug flat surfaces 58f or 58g contact camming surfaces 49b and as orientor 62 is lowered further into nipple 63, the lug flat surfaces sliding down surfaces 49b turn orientor 62 and the well tool to align lugs 58 for lowering into slots 49a. When desired, orientor 62 may be retrieved or lowered through nipple 63. When the orientor is lowered lug surface 58d contacts slot end surface 49c and cams the lugs inwardly.
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Disclosed are selective and no-go systems for injecting fluids in a well and a system for orienting a tool in a landing nipple in a well conduit, which is utilized in the selective set injection system. Each injection system is comprised of a land nipple, an injection mandrel having openings for flow and an orientor. The landing nipples have wall openings for flow and orienting means which are engaged by the mandrel orientor as the mandrel is lowered into the landing nipple, orienting the mandrel and aligning the mandrel flow openings with the nipple flow openings. There are orifices in the flow openings in both mandrels to control injected flow through the mandrel. The system for orienting a tool in a landing nipple has an orientor attachable to a well tool. This orientor and the selective orientor have lugs which engage an orienting sleeve in the nipple and are guided into slots when lowered into the sleeve. The slot bottoms have camming surfaces which cam the lugs inwardly permitting the orientor and selective injection mandrel to be lowered through their nipples.
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BACKGROUND OF THE DISCLOSURE
This invention relates to a gas driven gyroscope with an integrally contained gas source. More particularly it relates to improvements in gas driven gyroscopes which extend the rundown time or maintain higher speeds of the rotor during a specified time.
Gas driven gyroscopes with integrally contained gas sources are known which have a gas driven reaction rotor in one chamber and compressed inert gas in another chamber. Gas is released from one chamber by means such as puncturing a thin wall between the chambers. The gas, when released, flows through the hollow bore of the rotor shaft and outwardly through reaction passages in the rotor to cause it to spin. Changes in the gas pressure may also uncage the gyroscope gimbals after the rotor is spinning.
An example of the foregoing type of gas driven gyroscope is fully detailed in U.S. Pat. No. 3,393,569 issued July 23, 1968 to Lawrence J. Lief and assigned to the present assignee. The Lief patent is incorporated herein by reference and any of the various species of gas driven gyros shown in the Lief patent might employ the improvement of the present invention.
One advantage of a gas driven gyro, as compared to spring driven gyroscopes, is that it has a high ratio of usable energy in relation to its volume and weight. The potential energy in the compressed gas is quickly translated to rotational kinetic energy of the spinning rotor. The "rundown" of the rotor refers to the gradual decrease in rotor speed over time after the gas is expelled through the rotor passages. Various losses affect the rundown. One loss is caused by the reaction rotor acting as a pump rather than as a reaction turbine and acting to suck gas through the end of the shaft and pump it out the rotor exhaust ports thus reducing energy and causng more rapid slowing down of the rotor.
Accordingly, one object of the present invention is to provide an improved gas driven gyroscope with an extended rundown time, or having a higher average speed during a specified rundown time.
Another object of the invention is to provide an improved gas driven gyroscope with reduced losses during rundown.
Another object of the invention is to provide an improved device to shut off gas flow in a gas driven gyroscope with a reaction rotor.
DRAWINGS
The invention, both as to organization and method of practice, together with the objects and advantages thereof, will best be understood by reference to the following description, taken in connection with the accompanying drawings, in which:
FIG. 1 is a cross-sectional elevation view of a gas driven gyroscope,
FIG. 2 is a cross-section, taken along lines II--II of FIG. 1 through the rotor and rotor shaft,
FIG. 3 is an enlarged cross-sectional elevation view of the rotor shutoff valve which is the subject of the present invention,
FIG. 4 is a graph illustrating the improved operation of the invention.
SUMMARY OF THE INVENTION
Briefly stated, the invention is practiced by providing, in a gas driven gyroscope of the type having a gas driven reaction rotor in one chamber and compressed gas in another chamber with caging means including a conduit to conduct the compressed gas into the bore of the reaction rotor shaft, the improvement comprising a pressure responsive valve arranged to admit impelling gas to the rotor passages but to block gas flow through the rotor passages when the caging means conduit is disconnected.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 of drawing, the gyroscope includes a main housing 1 and a compressed gas housing section 2 attached thereto by bolts 3. The main housing defines a chamber 1a enclosing a gas reaction rotor 4 mounted on a hollow shaft 5. The rotor is of high density tungsten alloy and the shaft 5 is mounted in precision high speed bearings 6 supported by the inner gimbal 7. The inner gimbal is rotatably supported in the outer gimbal 8 which, in turn, is supported in bearings 9 in housing 1. The rotor and gimbals are "caged" prior to release of the gas by means of a caging mechanism shown generally at 10. Details of the operation of the caging and uncaging mechanism may be had by reference the aforesaid Lief patent. It should suffice to note that the caging mechanism 10 includes a piston 11 which is initially released and positioned by gas pressure and then caused to hold the caging plug 12 upward against a beveled portion 13 of the rotor shaft. When the gas pressure differential falls to a predetermined value, the caging plug 12 is withdrawn and the rotor and gimbals are uncaged. The caging mechanism also serves as a conduit to conduct compressed gas from an intermediate passage 14 to the interior of hollow rotor shaft 5. However when the caging plug 12 is withdrawn, the conduit is disconnected from one rotor shaft, which now has free access to the interior of housing 1.
The housing section defines a compressed gas chamber 2a which communicates with ports in the caging mechanism via the caging mechanism intermediate connecting passage 14 when a thin disc 15 is punctured in a known manner by an electrically operated pyrotechnic propelled piston 16. The operation of the puncturing mechanism which operates to release compressed inert gas from housing 2 into passage 14 is immaterial to the present invention, but details of several suitable types of mechanisms may be found by reference to the aforesaid Lief patent.
Referring to FIG. 2, the cross-section through the gas passages of rotor 4 indicates that it includes a plurality of circumferentially spaced nozzles 20 and that the shaft 5 also includes a plurality of circumferentially spaced gas admission ports 21 freely communicating with nozzles 20.
In operation, an inert gas, preferably nitrogen, at 3000 pounds per square inch is contained in housing 2 and is communicated via passage 14 and caging mechanism 10 to the interior of shaft 5 and thence to rotor nozzles 20 via ports 21. This causes the rotor 4 to spin at a high speed, preferably 36,000-50,000 R.P.M. depending upon the size of the gas chamber and the particular use to which the gyroscope is put. When the gas pressure within the main housing chamber 1a falls to a predetermined value, the caging mechanism 10 releases the rotor and gimbals, also disconnecting the conduit leading to the compressed gas passage 14.
The foregoing description describes a conventional known structure and is more fully described in the aforesaid Lief patent. In accordance with the present invention, a spring loaded pressure responsive valve device 25 is disposed in rotor shaft 5. The valve device includes a piston 26 which, prior to release of gas, is disposed as indicated in FIG. 1. Reference to the enlarged view of FIG. 3 shows that the valve 25 includes a stem 27 slidably disposed in the bore 28 of the rotor shaft 5.
A spring 29 around the stem normally holds piston 26 in the dotted line position indicated as 26' so that the piston blocks communication between the end of the shaft and the gas ports 21 leading to the rotor nozzles. A threaded nut 30 completes the valve assembly. Release of gas pressure from the compressed gas housing via the caging mechanism into the end of shaft 5 forces the piston 26 to move into the full line position shown in FIG. 3. Diminution of the pressure differential across the piston 26 when the impelling gas is expended allows it to return to the dotted line position 26'. In this position, it blocks the flow of gas through the shaft 5 into the rotor nozzle inlets.
OPERATION
The operation of the invention is as follows. When the gas driven gyroscope is actuated by the ignition mechanism 16 rupturing disc 15 and allowing gas to flow past the caging mechanism into the rotor shaft, piston 26 is displaced to allow the gas to flow through the nozzles and to spin rotor 4. The gyroscope is uncaged in the normal manner. When the pressure falls to a preselected value, piston 26 returns under the action of the spring and blocks the circulation of gas from the interior of shaft 5 into the rotor nozzle inlets. In this manner, the rotor 4 is prevented from pumping quantities of gas during rundown. The wheel can coast without sucking gas or air through the rotor nozzles. This substantially extends the rundown time required to reach a predetermined speed, or alternatively it substantially increases the average speed for a selected rundown time.
Reference to FIG. 4 of the drawing illustrates the improvement realized with a typical application. The graph of FIG. 4 represents time on the horizontal axis versus rotor R.P.M. on the vertical axis. The lower curve "A" shows a decrease of speed over time in a gas driven gyroscope of the type described without the invention and the upper curve "B" shows a rundown characteristic curve with the addition of the applicant's invention in the same gyroscope.
Thus there has been described an improved gas driven gyroscope which substantially improves the rundown characteristic of the gyroscope after release of the impelling gas. This is accomplished by a very simple spring loaded pressure responsive valve mechanism. Other equivalent forms of valves to block the flow of gas to the reaction rotor after the impelling gas has been expended will be apparent and included within the purview of the invention.
While there has been disclosed what is considered herein to be the preferred embodiment of the invention, other modifications will occur to those skilled in the art, and it is desired to include in the appended claims all such modifications as fall within the true spirit and scope of the invention.
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An improvement in gas driven gyroscopes of the type having a gas driven reaction rotor and integrally contained gas source. A spring loaded valve in the bore of the rotor shaft opens to admit the driving gas to the rotor nozzles and then closes to shut off the gas passages during rundown of the rotor so as to extend the rundown time.
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BACKGROUND OF THE INVENTION
Where cloth must be fed in rope form for processing as, for example, in systems such as the one disclosed in U.S. Pat. No. 3,780,544, difficulty is commonly encountered in maintaining adequate traction to avoid slippage at roll or reel members included in the system for feeding purposes.
The present invention provides a reel structure that is specially arranged to eliminate such slippage dependably during feeding, while avoiding any adverse effect on the cloth rope as the feeding takes place.
SUMMARY OF THE INVENTION
According to the present invention, the reel structure provided includes a plurality of spaced vanes that are disposed radially with respect to the reel axis in alternately inclined relation so that their projected profiles cross intermediate the wave length and consequently form a V-like channel through which the cloth rope is fed as the reel is rotated, while the outer edges of the vanes are shaped with a gently undulating configuration in each direction beyond the projected profile crossing to produce in combination with the V-like channel form the previously noted feeding action free of slippage and free of adverse effect on the cloth rope being fed.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a reel structure embodying the present invention;
FIG. 2 is a left end elevation of the FIG. 1 embodiment, slightly reduced in scale;
FIG. 3 is a detail of one of the reel vanes, indicating the projected profile crossing in broken lines; and
FIG. 4 is a tabulation specifying a preferred form of out vane edge configuration.
DETAILED DESCRIPTION OF THE INVENTION
The representative reel structure embodiment of the present invention shown in FIG. 1 comprises a central shaft 10 forming the axis of the reel and having journal portions 12 and 14 for mounting the reel for rotation, with one of these journal portions 14 being sufficiently longer to include a keyway at 14' so as to receive a driving connection thereat through which the reel may be rotated.
On the reel axis shaft 10, spaced circular heads 16 are carried transversely in fixed relation, and between these spaced heads 16 a plurality of alternately inclined vanes 18 and 20 are mounted in spaced planes radiating from the reel axis shaft 10. These vanes 18 and 20 are segment-shaped with the ends thereof truncated at proper angles so that one end thereof may be fixed at the inside face of one of the reel heads 16, while the other vane end extends short of the opposite reel head and is fixed at the reel axis shaft 10. The vanes 18 and 20 should be regularly spaced circularly between the reel heads 16, and at least three vanes should be spaced within 90° of the reel circumference (see FIG. 2).
Due to the alternately inclined arrangement of the vanes 18 and 20 their projected profiles cross intermediate their length, as indicated in FIG. 3, so that as noted earlier they form a V-like channel through which a cloth rope may be trained to travel for feeding as the reel is rotated. In addition, while the inner edges of vanes 18 and 20 are straight, the outwardly directed edges are formed with a gently undulate lengthwise configuration that extends substantially in both directions beyond the point of projected vane profile crossing which has the effect of preventing slippage of a cloth rope being fed by the reel.
FIG. 3 diagrams a vane 18 that has been found to operate with excellent effectiveness in a 131/2 inch diameter reel mounted on a shaft 10 having a diameter of one inch between its heads 16, and FIG. 4 specifies the radii locations for the outer vane edge undulations where the full X dimension is 61/2 inches and the full Y dimension is 61/4 inches, with the vane end attached to the adjacent head 16 being 11/2 inches wide and the other end attached to the shaft 10 being 2-1/16 inches wide.
The function of the undulate outer vane edges is to increase remarkably the tractive hold of the crossing vanes 18 and 20 on a cloth rope trained through the V-like channel they form. If processing conditions are such as to require a greater than normal pulling force on the cloth rope being fed, the effect is simply to cause the rope to move downwardly along the outer vane edges and be gripped more forcefully by the crossing vanes 18 and 20 to supply the greater pulling force required, while whenever the pulling force required lightens the cloth rope tends to climb upwardly along the vane edges due to the centrifugal force resulting from the reel rotation and the natural tendency of the cloth rope to spread as the required pulling force lightens. As a result, the cloth rope being fed by the disclosed reel structure reacts naturally at the outer vane edges to shift for whatever level of tractive gripping is needed to maintain the feeding without slippage, while at the same time avoiding any undue adverse handling of the cloth rope by the vanes 18 and 20.
The present invention has been described in detail above for purposes of illustration only and is not intended to be limited by this description or otherwise to exclude any variation or equivalent arrangement that would be apparent from, or reasonably suggested by, the foregoing disclosure to the skill of the art.
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A reel for feeding cloth in rope form is provided that employs a plurality of spaced vanes radially arranged in alternately inclined relation so that their projected profiles cross intermediate their length and the outer vane edges are formed with a gently undulating configuration beyond such crossing for particularly effective feeding action.
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BACKGROUND
The present invention relates to structures and methods that reduce damage from electrostatic discharge and/or shield against electromagnetic and radio frequency interference.
In electronic manufacturing, a worker may develop electrostatic charge from touching or rubbing surfaces as he works. Electrostatic discharge (ESD) from the worker to an electronic device can damage it. Grounding the machines, the worker, the walls, and the floor as well as controlling humidity will help, but not eliminate ESD damage especially if the device is transported around the factories.
Sensitivity to ESD damage increases as electronic devices such as semiconductors shrink in size. For example, if semiconductors have submicron size conductive channels, even tenths of a volt can cause a surge current that exceeds channel current capacity and fuses the channels.
It would be desirable to have structures and methods to reduce ESD damage especially during transportation and handling of electronic devices and if the structures and methods could be used to shield against electromagnetic interference (EMI) and radio frequency interference (RFI).
SUMMARY OF THE INVENTION
The present invention relates to structures and methods to reduce ESD damage and shield against EMI and RFI. By placing one or more parallel plate capacitors adjacent an electronic device the invention places one or more capacitors in series with the current flowing through the electronic device when there is ESD. The capacitance acts as a capacitive voltage divider to the ESD. After the discharge, the dissipative characteristics of the lossy dielectric of the physical structure cause the transferred electrical energy to be converted to thermal energy. The structure can be also used to reduce EMI/RFI.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates a structure made of a parallel plate dissipative capacitor that reduces ESD damage.
FIG. 1B illustrates a structure made of parallel plate dissipative capacitors in series that reduce ESD damage.
FIG. 1C is an electrical model of the structure of FIG. 1B in a nonconductive state.
FIG. 1D is an electrical model of the structure of FIG. 1B in a conductive state.
FIG. 2A illustrates a BGA package lid made of parallel plate dissipative capacitors in series.
FIG. 2B is an electrical model of the BGA package lid of FIG. 2A in nonconductive state.
FIG. 2C is an electrical model of the BGA package lid of FIG. 2A in conductive state.
FIG. 3A illustrates using a structure as an EMI/RFI shield for a building.
FIG. 3B illustrates using a structure for an antistatic container.
FIG. 3C illustrates using a structure for an antistatic bag.
FIG. 3D illustrates using a structure for an enclosure of a notebook computer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description includes the best mode of carrying out the invention. The detailed description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the claims.
We assign each part, even if structurally identical to another part, a unique reference number wherever that part appears in the drawings. A dashed circle indicates a part of a figure that is enlarged in another figure. The reference number tied to the dashed circle indicates the figure showing the enlarged portion.
FIG. 1A illustrates a structure made of a parallel plate dissipative capacitor that will reduce ESD damage. In an embodiment, a structure 10 is a parallel plate dissipative capacitor C 1 formed by sandwiching a dissipative dielectric layer 14 between a first conductive layer 12 and a second conductive layer 16 .
In the embodiment, the dissipative dielectric layer 14 includes a nonconductive dielectric doped with a voltage dependent resistive material that defines a conductive threshold voltage in the dissipative dielectric layer 14 . Some suitable nonconductive dielectrics include Mylar, polyethylene, polycarbonate, glass fiber laminates, plastic and paper fibers. One suitable voltage dependent resistive material is carbon nanotubes manufactured by Hyperion Catalysis International, Cambridge, Mass. In an embodiment, the carbon nanotubes are preferably 1.5–4.5% by weight of the dissipative dielectric layer 14 . Carbon nanotubes are electrically conductive polymers with a high aspect ratio. Electrical conductivity in the dissipative dielectric layer 14 is achieved through a quantum mechanism rather than through direct particle to particle contact thus exhibiting a nonlinear current voltage relationship (i.e., a non-ohmic relationship). Carbon Nanotubes for Static Dissipation , in Plastic Additives & Compounding, September 2001, volume 3, issue 9 , published by Elsevier, describes the characteristics and properties of carbon nanotubes, which is incorporated herein by reference.
The concentration of the voltage dependent resistive material in the nonconductive dielectric defines the conductive threshold voltage of the parallel plate dissipative capacitor C 1 . An ESD voltage that exceeds the conductive threshold voltage applied across first and second conductive layers 12 and 16 makes the dissipative dielectric layer 14 conductive. The resistance of the dissipative dielectric layer 14 decreases nonlinearly with increase in the ESD voltage. The ESD voltage is dissipated into thermal energy through current conduction in the dissipative dielectric layer 14 until the ESD voltage is depleted or removed and the parallel plate dissipative capacitor C 1 restores its capacitive function.
In other embodiments, low cost materials such as FR 1 , FR 2 and unfired ceramics may be used instead of doping a nonconductive dielectric with a voltage dependent resistive material. Such low cost materials exhibit inherent nonconductive dielectric and voltage dependent resistive characteristics with an associated conductive threshold voltage.
FIG. 1B illustrates a structure made of parallel plate dissipative capacitors in series that will further reduce ESD damage. The capacitors are made as described above in connection with FIG. 1A . In this embodiment, the structure 20 is made of capacitors C 2 , C 3 and C 4 . Conductive layers 22 and 26 sandwich dissipative dielectric layer 24 to form capacitor C 2 . Conductive layers 26 and 30 sandwich dissipative dielectric layer 28 to form capacitor C 3 . Conductive layers 30 and 34 sandwich dissipative dielectric layer 32 to form capacitor C 4 .
The concentration of the voltage dependent resistive material defines the conductive threshold voltage. In an embodiment, the concentration of the carbon nanotubes is preferably 1.5–4.5% of the total weight of each of the dissipative dielectric layers 24 , 28 , and 32 . The capacitance value which is a function of the dielectric properties and concentration of the voltage dependent resistive material defines a suitable thickness (e.g., 1–5 mils) for the dissipative dielectric layers 24 , 28 and 32 . The dissipative dielectric layer should be thin to better transfer the dissipated thermal energy to the adjacent conductors or to a heat sink.
FIG. 1C is an electrical model of the structure 20 of FIG. 1B made of parallel plate dissipative capacitors in series in a nonconductive state. In nonconductive state, the structure 20 has a return path connected to the ground for series capacitors C 2 , C 3 , and C 4 . If applied voltage V 1 is across the capacitors C 2 , C 3 , and C 4 , the total capacitance of the capacitors C 2 , C 3 , and C 4 is expressed by:
1/ Ctotal 1 =1 /C 2 +1 /C 3 +1 /C 4
If capacitors C 2 C 3 and C 4 are identical, the Ctotal 1 value is reduced to ⅓ of, e.g., capacitor C 2 :
Ctotal 1 =⅓ ×C 2 , when C 2 = C 3 = C 4
Each dissipative dielectric layers 24 , 28 and 32 ( FIG. 1B ) is a voltage divider and therefore dissipates ⅓ of the applied voltage V 1 . If there are N capacitors in series that are identical, each capacitor will dissipate 1/N of the applied voltage V 1 . The greater the number of capacitors in series, the smaller the voltage each capacitor has to dissipate. The ability of the dielectric layers to conduct heat to a heat sink as described in FIG. 1B limits the number of dissipative dielectric layers used in the structure 20 .
The conductive threshold voltage Vthsum 1 of the structure 20 is the sum of the conductive threshold voltages Vth 2 , Vth 3 , and Vth 4 of capacitors C 2 , C 3 and C 4 , expressed:
Vthsum 1 = Vth 2 + Vth 3 + Vth 4
If the applied voltage V 1 is equal or less than the sum of the conductive threshold voltage, Vthsum 1 , capacitors C 2 , C 3 , and C 4 remain in a nonconductive state and act as capacitors:
If V 1 <Vthsum 1 , C 2 , C 3 , and C 4 are capacitive.
FIG. 1D is an electrical model of the structure 20 of FIG. 1B made of parallel plate dissipative capacitors in series in the conductive state. If the applied voltage V 1 is greater than the conductive threshold voltage Vthsum 1 , the capacitors C 2 , C 3 , and C 4 act not as capacitors but as a voltage dependent resistor R 1 :
If V 1 >Vthsum 1 , C 2 , C 3 , and C 4 act as a voltage dependent resistor R 1 .
Excess voltage ΔV 1 is the difference between the applied voltage V 1 and the conductive threshold voltage Vthsum 1 , expressed:
V 1 − Vthsum 1 =Δ V 1 excess voltage
Electrical conductivity in dissipative dielectric layers 24 , 28 and 32 is achieved through quantum mechanism at excess voltage ΔV 1 . The voltage dependent resistor R 1 exhibits resistance that is inversely proportional to the excess voltage ΔV 1 . Capacitors C 2 , C 3 , and C 4 can be modeled by a voltage dependent resistor R 1 in series with a small inductor L 1 where the current 11 is proportional to the differential change of the excess voltage ΔV 1 over time, expressed:
I 1 = Ctotal 1 ×dΔV 1 / dT
The current 11 flows through the structure 20 from the conductive layer 22 to the conductive layer 34 or vice versa depending on the voltage polarity across the structure 20 ( FIG. 1B ). The excess voltage ΔV 1 is dissipated into thermal energy in the dissipative dielectric layers 24 , 28 and 32 , and decreases over time following a RC time constant exponential decay relationship until ΔV 1 is depleted.
FIG. 2A illustrates a ball grid array (BGA) package 40 with a lid 41 made of parallel plate dissipative capacitors in series. The lid 41 includes parallel plate dissipative capacitors C 5 and C 6 in series in a range of 100 pF to 1000 pF such as 500 pF. Capacitors C 5 and C 6 have dissipative dielectric layers 44 and 48 sandwiched by conductive layers 42 , 46 and 50 with a total conductive threshold voltage Vthsum 2 . The lid 41 seals the stiffener 52 with an adhesive 51 . The stiffener 52 is the body of the BGA package that is made of conductive structure such as aluminum or copper. Capacitor C 7 has a value of 500 pF and is formed by the dielectric layer of the adhesive 51 sandwiched between the conductive layer 50 and the stiffener 52 . The stiffener 52 is brazed to the interposer 56 , i.e., the BGA substrate, and the BGA package 40 is attached to the printed wired board (PWB) 59 through the melted solder ball 58 in the bottom of the interposer 56 . A semiconductor device 54 is brazed onto the interposer 56 . Capacitor C 8 with a value of less than 300 pF is formed by the top and bottom metallization of the semiconductor device 54 . The value of capacitor C 8 is usually small compared to the capacitors C 5 and C 6 of the lid 41 . Capacitors C 5 and C 6 are in series to the capacitors C 7 and C 8 .
FIG. 2B is an electrical model of the BGA package 40 shown in FIG. 2A in a nonconductive state with an applied voltage V 2 less than or equal to the conductive threshold voltage Vthsum 2 . The total capacitance seen by the device 54 is:
1/ Ctotal 2 =1 /C 5 +1 /C 6 +1 /C 7 +1 /C 8
The series capacitors C 5 to C 8 form a voltage divider circuit where the voltage across each capacitor is inversely proportional to its capacitance.
FIG. 2C is an electrical model of the BGA package 40 shown in FIG. 2A in a conductive state with an applied voltage V 2 greater than the conductive threshold voltage Vthsum 2 . The difference is the excess voltage ΔV 2 as follows:
V 2 − Vthsum 2 =Δ V 2 (excess voltage)
Under this condition, the capacitors C 5 and C 6 are modeled as a voltage dependent resistor R 2 with an illustrative value of 10 k ohm with a series inductance L 2 with a value of 0.3 nH and capacitors C 7 and C 8 are relatively nonconductive. The current 12 is proportional to the differential change of the excess voltage ΔV 2 over time until V 2 is less than or equal to conductive threshold voltage Vthsum 2 :
I 2 =( Ctotal 2 )* dΔV 2 / dT
For example, if the voltage dependent resistor R 2 is about 10 k ohm, capacitor C 7 is about 500 pF and capacitor C 8 is about 300 pF, the RC time constant is less than 2 micro second. The excess voltage ΔV 2 is dissipated into thermal energy and decreases with exponential decay following an RC time constant in the dissipative dielectric layers 44 and 48 . The generated heat is conducted from the lid 41 to the PWB 59 through the stiffener 52 and to the interposer 56 .
FIG. 3A illustrates using the structures of FIG. 1A or FIG. 1B as an EMI/RFI shield. A structure 62 is laminated using known adhesives and/or pressure on each of the windows of a building 60 . The EMI/RFI shield that results improves wireless LAN communication security where microwave and radio frequencies would penetrate the building without the EMI/RFI shield. The radiated energy can be reduced by the dissipative dielectric layer of the structure 62 .
FIGS. 3B–3C illustrate using the structures of FIG. 1A or 1 B as an antistatic container 64 and an antistatic bag 70 for transporting electronic devices. The structures can also form the interior surface 66 and the exterior surfaces 68 , 72 on some rigid or flexible material. The antistatic container 64 and an antistatic bag 70 act as a Faraday cage to shield and dissipate the ESD voltage to prevent ESD damage to the electronic devices inside.
FIG. 3D illustrates using the structure of FIG. 1A or FIG. 1B for an enclosure adjacent or part of the monitor enclosure 76 and the enclosure case 78 of a notebook computer 74 . This allows ESD mitigation to the components in the notebook computer 74 as well EMI/RFI shielding.
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The present invention relates to structures and methods that reduce ESD damage to electronic devices. In an embodiment, the structure is a parallel plate dissipative capacitor formed by sandwiching a dissipative dielectric layer between two conductive layers in series to the electronic device. The dissipative dielectric layer includes a nonconductive dielectric doped with a voltage dependent resistive material that defines a conductive threshold voltage. The structure functions as a voltage dependent resistor in response to an applied voltage such as an ESD surge voltage exceeding the defined conductive threshold voltage and dissipates the applied voltage into thermal energy before it can reach the electronic device and cause damage. The dissipative dielectric layer restores to a dielectric and the structure functions as a capacitor when the excess voltage is depleted that is drops below the defined conductive threshold voltage. In another embodiment, the structure is a parallel plate dissipative capacitors in series that enhances ESD mitigation through a capacitive voltage divider structure. The structures can be used in EMI/RFI shielding applications.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the manufacture of uniform, high quality, glass fiber mat products made by the wet-laid process, and, more particularly, it is concerned with a method of improving the wet-strength of freshly prepared, wet glass fiber mats, so that they can be conveniently handled and transferred, even mutually, in the production line.
2. Description of the Prior Art
High strength, uniform thin sheets or mats of glass fibers are finding increasing application in the building materials industry, as for example, in asphalt roofing shingles and as backing sheets for vinyl flooring. These glass fiber mats are replacing similar sheets made traditionally of asbestos fibers. Glass fiber mats usually are made commercially by a wet-laid process, which is carried out on modified paper or asbestos making machinery, as described, for example, in the book by O. A. Battista, Synthetic Fibers in Papermaking (Wiley) N.Y. 1964. A number of U.S. patents also provide a rather complete description of the wet-laid process, including U.S. Pat. Nos. 2,906,660; 3,012,929; 3,050,427; 3,103,461; 3,228,825; 3,760,458; 3,766,003; 3,838,995 and 3,905,067. The German OLS No. 2454354 (Fr. Demande No. 2,250,719), June, 1975, also is pertinent art in this field.
In general, the known wet-laid process for making glass fiber mats comprises first forming an aqueous suspension of short-length glass fibers under agitation in a mixing tank, then feeding the suspension through a moving screen on which the fibers enmesh themselves into a freshly prepared wet glass fiber mat, while the water is separated therefrom. However, unlike natural fibers, such as cellulose or asbestos, glass fibers do not disperse well in water. Actually, when glass fibers, which come as strands or bundles of parallel fibers, are put into water and stirred, they do not form a well-dispersed system. In fact, upon extended agitation, the fibers agglomerate as large clumps which are very difficult to redisperse.
In an attempt to overcome this inherent problem with glass fibers, it has been the practice in the industry to provide suspending aids for the glass fibers, including surfactants, in order to keep the fibers separated from one another in a relatively dispersed state. Such suspending aids usually are materials which increase the viscosity of the medium so that the fibers can suspend themselves in the medium. Some suspending aids actually are surfactants which function by reducing the surface attraction between the fibers. Unfortunately, however, none of the available suspending aids are entirely satisfactory for large volume manufacture of useful, uniform glass fiber mats.
In our copending patent application, Ser. No. 851,863, filed Nov. 15, 1977, there is described an improved method of preparing chopped glass fiber dispersions in water by admixing the fibers with a small amount of an amine oxide. While the present invention is not limited to this method of forming the initial glass fiber dispersions, it is to be considered a preferred embodiment thereof, and the examples which follow will reflect the advantageous use of amine oxide surfactants to form the initial glass fiber dispersions. However, any other dispersant may be used, including the select quaternary ammonium cationic surfactants described in our copending application, Ser. No. 876,651, filed Feb. 10, 1978 which compounds have the following formula: ##STR1## where R 1 , R 2 , R 3 and R 4 are selected from the group consisting of aliphatic and aromatic hydrocarbon radicals, straight chain or branched, or two or more form a cyclic group, saturated or unsaturated, substituted or unsubstituted, at least two of said radicals containing at least 10 carbon atoms each, being the same or different, the sum of the carbon atoms in R 1 , R 2 , R 3 and R 4 being at least 22 and less than about 48, and X is an anion.
Of course, since the dispersing aid acts to suspend the individual glass fibers away from each other, the wet-strength of the wet mat formed on the screen may be lessened to some degree by the use of good dispersion aids, such as amine oxides.
The poorer wet-strength of such mats, however, does not mean poor strength of the dry mats and/or of the final dry and resin-bonded mat product, but it can create some problems during further processing of the wet mat. In commercial production of glass mats, for example, the wet mat formed on the foraminous belt is transferred to other units, such as the drying and the bonding resin application units of the production line. In each of these units, the wet mat is supported on felts or drums; however, it does remain unsupported at the transfer points from one unit to another. Furthermore, at the front end of the line, the wet mat from the foraminous belt often is manually transferred from one unit to another. If the wet mat as formed is too weak, it cannot be easily transferred manually from one unit to another. Furthermore, poor wet strength leads to occasional breakage of the mat in unsupported transfer areas during production, leading to undesirable interruptions and material waste.
The materials applied to the wet-mat in this invention to improve its wet-strength is to be distinguished from the conventional resin binders which are applied to the dry mat product. The former materials are used herein only to improve the wet strength of the wet mat sufficient to enable it to be transported, even manually, through the production line.
In general, for a wet-laid glass fiber process to be effective, it is necessary that it meet several rigid criteria simultaneously which can provide means for making the desired high quality, uniform finished glass fiber mat product at a rapid rate of production in an economically acceptable process. For example, the process preferably should provide a uniform dispersion of glass fibers in water effectively at low surfactant concentrations, at high glass fiber consistencies, preferably not be accompanied by a substantial increase in the viscosity of the medium, and should be capable of producing wet glass fiber mats at the screen which have a uniform distribution of fibers characterized by a multidirectional array of fibers.
The process also should provide means for improving the wet-strength properties of such freshly prepared wet glass fiber mats, so that it can be conveniently transferred, even manually, to other units in the production line, such as the drying and binding units, without tearing or breaking the wet mat during handling. The means for improvement in wet-strength of such wet mats should be effective for such mats formed from any suspending aid or dispensing surfactant, even with those which provide excellent glass fiber dispersions. The materials used for treating the wet mats to improve its strength preferably should be readily available, at low cost, and be capable of use either by direct spraying in dilute solution onto the wet mats at any convenient point in the production line.
These and other objects and features of the invention will be made apparent from the following more particular description of the invention.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided herein an improved method for making glass fiber mats by the wet-laid process. The current invention is concerned particularly with a method of improving the wet-strength of wet mats made from surfactant-aided glass fiber dispersions, such as described in the aforementioned copending application. The process of improving the wet-strength of these mats, according to this invention, comprises treating the wet mat with a dilute solution of an anionic polyelectrolyte surfactant. A convenient method of carrying out this post-treatment consists of spraying the solutions directly onto the wet mats, whereupon its wet strength is improved dramatically and immediately. The solution may be applied to the wet mat at any convenient point in the production-flow; however, usually it is advisable to apply it upon formation of the wet mat at the screen. Subsequent processing of the treated mat then can be carried out without possibility of tearing or breaking of the mat.
DETAILED DESCRIPTION OF THE INVENTION
Anionic polyelectrolytes suitable for use herein are those which are either soluble in water or can provide a soluble or dispersable salt in water, such as with an alkali metal hydroxide, ammonia or a low molecular weight organic amine. The anionic polyelectrolyte has the structural formula: ##STR2## wherein each R can be the same or different and is selected from the group consisting of hydrogen, lower alkoxy, hydroxy, lower alkylcarbonyloxy, hydroxy lower alkyl, lower alkyl, phenyl, carboxy, lower alkoxycarbonyl, lower alkylcarbonyloxy lower alkyl, amido and carbamyl, with the proviso that only one R can be lower alkyl or phenyl; wherein X, Y and Z can be the same or different and are each selected from the group consisting of hydrogen, lower alkyl, carboxy, lower alkoxycarbonyl, with the proviso that at least one of X, Y and Z be selected from the group consisting of carboxy and lower alkoxycarbonyl, and, when X and Y are each lower alkoxycarbonyl, Z is carboxy or lower alkoxycarbonyl, with the further proviso that only one of X, Y and Z can be lower alkyl; a can be 0 to less than 1 and a+b=1; n is a whole integer which ranges from about 5 to about 10,000.
The equivalent weight of the polyelectrolyte preferably is less than 200, calculated as the acid form. The term "equivalent weight" as used herein is intended to denote the equivalent weight of the substance in grams, which is calculated by dividing its formula weight by its valency. In the present case of the acids, the valency is the number of replaceable hydrogen atoms.
Typical of the polyelectrolytes encompassed by the above structural formula are the homopolymers of acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and their copolymers with one or more copolymerizable monomers such as acrylamide, an acrylonitrile hydrolyzate, lower alkyl esters of unsaturated aliphatic acids as described above, lower alkyl vinyl ethers, ethylene, styrene, and the like. Preferably, the polyelectrolyte is a polyacrylic acid, polymethacrylic acid or copolymers of acrylic and methacrylic acids, and maleic acid with methyl vinyl ethers.
Although polyelectrolytes of a wide range of molecular weight having a degree of polymerization (n) from 5 to 10,000 can be employed in the present invention, the preferred polyelectrolytes exhibit a degree of polymerization (n) ranging from about 50 to about 3,000.
Specific anionic polyelectrolytes useful in the invention thus include polyacrylic acid, polymethacrylic acid, polymaleic acid, polyitaconic acid, copolymaleic acid/acrylic acid, copolymaleic acid/methylvinyl ether, half methyl and ethyl esters of copolymaleic acid/methyl vinyl ether. Others are described in U.S. Pat. No. 3,377,249 and are included herein by reference.
In a typical wet-laid process for making glass fiber mats, a stock suspension of the fibrous material of predetermined fiber consistency is prepared in a mixing tank. The suspension then is pumped into a head box of a papermaking machine where it may be further diluted with water to a lower consistency. The diluted suspension then is distributed over a moving foraminous belt under suction to form a non-woven fiber structure or wet mat on the belt. This wet mat structure then is treated as described herein to improve its wet-strength. The thus-treated wet-mat may be dried, if necessary, then furnished with a resin binder, and, finally, thoroughly dried to give a finished non-woven glass fiber mat product.
The initial glass fiber filaments or strands generally are chopped into bundles of fibers about 1/4" to 3" in length, usually about 1/2" to 2", and preferably about 1" long, and usually about 3 to 20 microns in diameter, and, preferably about 15 microns. In a preferred embodiment of the invention, the glass fibers are added to water containing an amine oxide surfactant, which forms a well-dispersed fiber composition. Suitably, the amine oxide is present at a concentration of about 5-500 ppm of the solution and preferably about 10-25 ppm. Alternatively, the chopped glass fibers may be coated initially by spraying or otherwise applying the amine oxide surfactant thereon, and then dispersing the coated fibers in the aqueous medium. Suitably, the coated fibers contain about 0.01 to 1% by weight of the amine oxide, and, preferably, between 0.025 to 0.25%. Other suspending aids or surfactants known in the art also may be used, however.
The glass fibers may be dispersed in the amine oxide surfactant at relatively high fiber consistencies while still retaining the effective dispersion characteristics of the composition. For example, a fiber consistency of from about 0.001% to about 3.0% may be used, and, preferably, about 0.05% to about 1% is employed, based upon the weight of the fibers in the water. Such compositions furnish excellent dispersions when agitated in conventional mixing equipment. As mentioned, if desired, the highly concentrated fiber dispersion compositions may be diluted at the head box, usually to a consistency of about 0.1% to about 0.3%, and, preferably about 0.2%, which, however, is still a highly concentrated fiber dispersion by conventional standards.
The dispersion compositions are formed without any substantial change in the viscosity of the medium or of generation of unwanted foams during the process. Furthermore, the dispersions preferably are prepared at or near a neutral pH condition, or perhaps under slightly alkaline conditions, again, without affecting the good quality of the dispersions, or of the finished glass mat products produced therefrom.
These dispersion compositions produce wet glass fiber mats which have a high density of fibers therein and which are uniformly distributed throughout the mat in a multidirectional array. The finished mats show excellent tensile strength properties, too. The rate of production of the mats is very rapid, indeed, in this invention. In fact, a rate of mat production of over 500 linear ft./min. using conventional paper-making equipment is readily achievable in this process.
The amine oxide surfactants for forming the initial glass fiber dispersing are tertiary amine oxides having the formula: ##STR3## where R 1 , R 2 and R 3 suitably are hydrocarbon groups containing between 1-30 carbon atoms. The hydrocarbon groups can be aliphatic or aromatic, and, if aliphatic, can be linear, branched or cyclic in nature, and can be the same or different in each radical. The aliphatic hydrocarbon radical can contain ethylenic unsaturation. Preferably the aliphatic groups are selected from among alkyl groups, such as lower alkyl or hydroxyalkyl groups having from 1-4 carbon atoms, and substituted alkyl groups thereof, or long chain alkyl groups, having from 12-30 carbon atoms, such as stearyl, laurel, oleyl, tridecyl, tetradecyl, hexadecyl, dodecyl, octadecyl, nonadecyl, or substituted groups thereof, derived from natural or synthetic sources. The sum of the R 1 , R 2 and R 3 groups is about 14-40 carbon atoms, and most preferably, about 18-24 carbon atoms.
Typical amine oxides include Aromox DMHT from Armak, a dimethyl hydrogenated tallow amine oxide, Ammonyx SO from Onyx, a dimethylstearylamine oxide, Aromox DM16 from Armak, a dimethylhexadecylamine oxide, and Aromox T/12 from Armak, a bis(2-hydroxyethyl) tallow amine oxide, where R T =3% tetradecyl, 27% hexadecyl, 16% octadecyl, 48% octadecenyl and 6% octadecadienyl. R HT =hydrogenated R T (saturated), although others known in the art may be used as well.
The examples which follow will further illustrate the invention, but are not to be considered as being limiting of the principles or practice of the invention.
EXAMPLE 1
Formation Of Wet Glass Fiber Mats By Wet-Laid Process (Laboratory Control Experiment)
To 7 liters of a 50 ppm solution of dimethylhydrogenated tallowamine oxide (Aromox DMHT from Armak) was added 7g of chopped E-glass (11/2" long, 15 microns diameter), with stirring, to form a good fiber dispersion. The dispersion then was carried through a laboratory Williams paper-making apparatus to form a 10"×11" (=110 sq. inches) wet mat. The glass fibers in this wet mat were very evenly distributed throughout; however, it was too weak to be lifted by holding at the two corners. It could be transferred from the frame of the apparatus to another flat support (for drying) only by putting the flat surface on the frame and carefully turning the frame upside down.
EXAMPLES 2-9
(Invention Experiments)
EXAMPLE 2
The procedure of Example 1 was repeated except that the wet mat was sprayed lightly with a 0.5% aqueous solution of Gantrez® S-95 (copolymaleic acid methylvinyl ether) from GAF. The wet mat now showed excellent wet-strength properties, it could be easily lifted up from the frame byholding its two corners and transferred directly to another support for drying. The dried, finished mat had good mat qualities.
EXAMPLE 3
The procedure of Example 2 was repeated using a 0.5% aqueous solution of the partial sodium salt (pH=7) of Gantrez® ES-225 (half methyl ester of copolymaleic acid methyl vinyl ether) from GAF. The wet strength of the mat after spraying with this material was similar in strength to that of Example 2.
EXAMPLE 4
The procedure of Example 2 was repeated using a 0.5% solution of polyacrylic acid (MW 30,000) with similar results in improved wet-strength properties of the wet mat.
EXAMPLE 5
The procedure of Example 2 was repeated using a 0.5% solution of polyitaconic acid (MW 30,000). The wet strength was improved to the same extent as in the previous examples.
EXAMPLE 6
The procedure of Example 2 was repeated using polymethacrylic acid with similar results.
EXAMPLE 7
The procedure of Example 2 was repeated using polymaleic acid with similar results.
EXAMPLE 8
The procedure of Example 2 was repeated using copolymaleic acid/acrylic acid with similar results.
EXAMPLE 9
The procedure of Example 2 was repeated using the half ethyl ester of copolymaleic acid/methyl vinyl ether with similar results.
EXAMPLE 10
(Pilot Production Unit Control Experiment)
In this example, a conventional pilot production unit was employed. Accordingly, a 0.5% fiber glass dispersion was prepared in a mixing tank using a 20 ppm solution of dimethyl hydrogenated tallowamine oxide -- (Aromox DMHT) from Armak. The fiber glass used was chopped E-glass (15 micron diameter and 11/2" long). This dispersion was pumped into the headbox of the pilot machine and simultaneously diluted with fresh 20 ppm solution of dimethyl hydrogenated tallow amine oxide to give a final glass fiber consistency in the headbox of 0.14%. This diluted dispersion then was distributed onto a moving foraminous belt at such a rate that a wet mat of about 2 lbs. glass/100 sq. ft. was obtained. The wet mat so formed was of excellent quality insofar as uniformity of fiber distribution and fiber array was concerned; however, it had relatively poor wet-strength characteristics as formed. As a result, it was difficult to transfer this wet mat from the belt to the surfaces of the drum dryers across an unsupported gap of about 9 inches. The wet mat often broke as it was being manually transferred and even though the continuous wet mat flowed from the belt to the drier, the wet mat often broke at the unsupported junctions whenever the machine was stopped or if extra tension was applied at the unsupported bridging points.
EXAMPLE 11
The procedure of Example 10 was repeated except that the wet mat as it was formed in the foraminous belt was sprayed with a 0.1% solution of Gantrez ® S-95 (copoly maleic acid methyl vinyl ether) from GAF. The thus-treated wet mat had sufficient wet-strength to be easily transferred manually to the drum driers without breakage.
EXAMPLE 12
(Control Experiment - Coated Glass Fibers)
7g of chopped E-glass was added to 700 ml. of a 0.25% solution of Ethomeen ® T-25 (poly (15) ethoxylated tallowamine) from Armak. The mixture was agitated for a few minutes and filtered in a Buchner funnel under suction. The glass fibers, after filtration, retained about 40% of their own weight of the solution. The coated glass fibers then were air dried and suspended in 700 ml of a 0.1% solution of Arquad ® 18 (stearyl trimethyl ammonium chloride) from Armak, and agitated, whereupon a usable suspension of the glass fibers resulted. This suspension then was used to make a 10"×11" (110 sq. inches) wet mat using the paper-making apparatus. This wet mat, howeve, again, was too weak to be lifted up from the frame by holding at its two corners.
EXAMPLE 13
The procedure of Example 12 was repeated except that in addition the wet mat was sprayed with a 0.5% solution of Gantrez ® S-95 (copoly maleic acid methyl vinyl ether) from GAF. The treated mat now was strong enough to be lifted intact by holding its two corners.
EXAMPLE 14
The procedure of Example 13 was repeated except that polyacrylic acid (MW=30,000) was used in place of the above solution. The thus-treated wet mat again was much stronger so that it could be handled manually for further processing.
While the invention has been described with particular reference to certain embodiments thereof, it will be understood that certain changes and modifications may be made which are within the skill of the art. Accordingly, it is intended to be bound by the appended claims only.
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In accordance with the present invention, there is provided herein a method of increasing the strength of wet glass fiber mats prepared by the wet-laid process. The wet-strength of such freshly prepared glass fiber mats are improved in this invention by treating the wet mat with a dilute solution of an anionic polyelectrolyte. As a feature of the invention, the wet-strength of such mats are increased substantially so that they may be conveniently handled and transferred, even manually, for further processing, e.g. for applying binders and drying, into the finished glass fiber mat product.
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BACKGROUND AND SUMMARY OF THE INVENTION
[0001] The present invention relates to a disc brake and, more particularly, to a disc brake caliper slide pin having a tapered design.
[0002] Automotive components are typically exposed to a wide variety of environmental inputs including variations in temperature and load throughout operation of a vehicle. Use of a vehicle over rough surfaces provides a road load vibrational input as well. To assure proper operation of a vehicle component, it is desirable to maintain the structural integrity of the component or assembly for an extended time period.
[0003] Brake assemblies typically include a number of components interconnected to one another via threaded fasteners. To assure proper braking operation, it is desirable that the thread fasteners maintain a desired clamp load during and after exposure to the environmental and operational inputs previously discussed. Some bolted joints have experienced reduced clamp load or “backing-off” for a number of reasons. One reason relates to joint relaxation where a relatively short bolt or shaft is initially loaded to exhibit a relatively small elongation. If the bolt relaxes, the relatively small elongation is no longer present and the joint clamp load decreases. In addition, the clamping force generated by a threaded fastener may be insufficient if the surface area between any two components within the joint is insufficient to maintain the clamp load without yielding. In this case, relatively high contact stresses are generated between clamped components causing a portion of one of the clamped components to yield or flow when clamped. The yielding of the material reduces the fastener elongation and the clamp load is greatly decreased.
[0004] The present invention provides a disc brake having a tapered slide pin designed to maintain a desired location during operation of the brake and the vehicle.
[0005] In particular, the present invention relates to a disc brake operable to apply a clamping force to a rotatable disc. The disc brake includes a support bracket, slide pins coupled to the support bracket, inner and outer brake shoes and a caliper supported by the slide pins. The support bracket is a substantially rectangular frame defining a window. The window is adapted to accept a portion of a disc protruding therethrough. The support bracket includes a pair of spaced apart apertures extending through the frame where each aperture includes a threaded portion and a conical seat extending along an axis aligned to intersect the disc. The slide pins are threadingly engaged with a threaded portion. The slide pins do not extend through the window but protrude outwardly away from the window. Each slide pin has a tapered portion in engagement with one of the conical seats.
[0006] Additionally, the present invention relates to a disc brake having a disc rotatable about a laterally extending axis, a support bracket, slide pins coupled to the support bracket and a caliper slidably supported by the slide pins. The support bracket has first and second spaced apart, substantially parallel legs as well as third and fourth spaced apart, substantially parallel legs. The first and second legs are interconnected at their ends by the third and fourth legs to define a window. The first leg has spaced apart pin apertures where each pin aperture includes a threaded portion and a tapered portion extending along an axis. Each pin aperture is substantially parallel to the disc axis of rotation and radially positioned within the outer diameter of the disc. The slide pins have a threaded end and a tapered portion adjacent the threaded end. Each threaded end engages the threaded portion of one of the pin apertures. The tapered portion of each slide pin is driven into engagement with the tapered portion of each pin aperture by rotation of the slide pin relative to the support bracket. The caliper is slidably supported by the slide pins and includes a piston cavity for moveably supporting the piston. The piston cavity has an axis extending substantially parallel to and radially inward of the slide pin axes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0008] FIG. 1 is an exploded perspective view of an exemplary disc brake constructed in accordance with the teachings of the present invention;
[0009] FIG. 2 is a perspective view of the assembled disc brake without the disc;
[0010] FIG. 3 is a perspective view of the assembled disc brake from another view;
[0011] FIG. 4 is a cross-sectional view taken along line 4 - 4 as shown in FIG. 2 ;
[0012] FIG. 5 is a cross-sectional view taken along line 5 - 5 as shown in FIG. 2 ; and
[0013] FIG. 6 is a schematic depicting the radial locations of the piston bores, the slide pin apertures and the brake support apertures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0015] With reference to FIGS. 1-6 , a disc brake constructed in accordance with the teachings of the present invention is identified at reference numeral 10 . Disc brake 10 is operable to selectively clamp an inboard brake shoe 12 and an outboard brake shoe 14 against a rotatable disc 16 to decelerate a vehicle (not shown). Disc brake 10 includes a support bracket 18 adapted to mount to a steering knuckle or axle component of the vehicle to support disc brake during operation. A first slide pin 20 and a second slide pin 22 are mounted to support bracket 18 in a manner to resist vibratory loosening as will be described in greater detail hereinafter. First slide pin 20 and second slide pin 22 laterally inwardly protrude from support bracket 18 . A caliper 24 is slidably supported on first slide pin 20 and second slide pin 22 . A first piston 26 and a second piston 28 are slidably supported within caliper 24 . First piston 26 and second piston 28 are moveable via hydraulic pressure being selectively supplied to caliper 24 . Inboard brake shoe 12 and outboard brake shoe 14 are positioned on opposite wear surfaces of disc 16 . Caliper 24 at least partially envelops inboard brake shoe 12 and outboard brake shoe 14 such that axial movement of first piston 26 and second piston 28 cause the brake shoes to clamp on disc 16 .
[0016] More particularly, brake support bracket 18 is a one-piece frame-shaped member preferably constructed by a casting or forging process. Support bracket 18 includes a first leg 30 , a second leg 32 , a third leg 34 and a fourth leg 36 . First leg 30 is a substantially linear elongated member positioned substantially parallel to second leg 32 . Second leg 32 is arched in a radial direction in relation to a laterally extending axis 38 about which disc 16 rotates. One end of first leg 30 is interconnected to one end of second leg 32 via third leg 34 . The opposite ends of legs 30 and 32 are interconnected by fourth leg 36 . First leg 30 includes a first detent 40 and a second detent 42 .
[0017] Inboard brake shoe 12 includes a lining block 43 mounted on a backing plate 44 . Backing plate 44 includes integrally formed tabs 46 and 48 protruding from each end. Detents 40 and 42 restrict inboard brake shoe 12 from radial movement but allow lateral movement of the brake shoe. Clips 50 may be inserted within detents 40 and 42 to assist in maintaining the proper position of inboard brake shoe 12 during operation. Second leg 32 includes a similar pair of detents 52 and 54 . Outboard brake shoe 14 includes a lining block 55 mounted to a backing plate 56 . Backing plate 56 includes integrally formed tabs 58 and 60 protruding from each end. Clips 62 cooperate with detents 52 and 54 to restrain tabs 58 and 60 from linear movement while allowing lateral movement parallel to axis 38 .
[0018] First leg 30 includes a pair of brake mounting apertures 64 operable to receive brake fasteners to couple support bracket 18 to a knuckle or other vehicle suspension component. Caliper 24 , inboard brake shoe 12 and outboard brake shoe 14 are supported via this structural interconnection. Support bracket 18 also includes a first slide pin aperture 66 and a second slide pin aperture 68 . Slide pin aperture 66 extends laterally through first leg 30 along a first slide pin axis 69 . Slide pin aperture 66 includes an internally threaded portion 70 and a tapered portion 72 . Slide pin 20 is threadingly engaged with pin aperture 66 and protrudes laterally inboard along axis 69 .
[0019] As best shown in FIG. 4 , slide pin 20 is a substantially cylindrical member having a body portion 74 with a substantially smooth outer cylindrical surface 76 . A groove 78 is formed in body portion 74 and is in receipt of a bushing 80 . Bushing 80 functions to isolate the slide pin 20 from the caliper body to reduce caliper rattle on the slide pins. First slide pin 20 also includes a tapered portion 82 and a threaded portion 84 . Threaded portion 84 is positioned at a first end 86 . A drive recess 88 is positioned at a second opposite end 90 . First slide pin 20 is coupled to support bracket 18 by inserting a drive tool within drive recess 88 and rotating first slide pin 20 relative to support bracket 18 . First slide pin 20 is rotated until tapered portion 82 drivingly engages tapered surface 72 to form a press-type fit. An axially collapsible bellows 92 has a first end 94 coupled to first slide pin 20 . A second end 96 of bellows 92 is secured to a boss 98 formed on caliper 24 .
[0020] Caliper 24 includes a pin bore 100 in receipt of first slide pin 20 . A running-class fit exists between outer cylindrical surface 76 of first slide pin 20 and pin bore 100 to allow caliper 24 to translate laterally relatively to support bracket 18 during operation. Bellows 92 is operable to axially extend and compress to account for the relative movement between caliper 24 and support bracket 18 . A cap 102 engages boss 98 and covers pin bore 100 . Cap 102 is removable to allow access to drive recess 88 should brake service and removal of first slide pin 20 be required.
[0021] Caliper 24 is a generally “C” shaped member having an inboard side portion 104 and an outboard side portion 106 interconnected by a laterally extending bridge portion 108 . First side portion 104 includes boss portion 98 as well as another boss portion 109 substantially similar to boss 98 . Furthermore, first side portion 104 includes a first piston bore 110 and a second piston bore 112 . First piston 26 is slidably positioned within first piston bore 110 to move along a first piston bore axis 113 . A first piston seal 114 sealingly engages first piston 26 and first side portion 104 to protect the piston bore from ingress of contamination. Similarly, second piston 28 is slidably positioned within second piston bore 112 to move along a second piston bore axis 115 . A second piston seal 116 sealingly engages second piston 28 and first portion 104 . First piston 26 and second piston 28 are operable under hydraulic fluid pressure entering a port 118 to apply a force to backing plate 44 of inboard brake shoe 12 .
[0022] Outboard side portion 106 includes a surface 120 in engagement with backing plate 56 of outboard brake shoe 14 . A pair of cut-outs 122 extend through outboard side portion 106 to allow tooling (not shown) sufficient access to form first piston bore 110 and second piston bore 112 . Outboard side portion 106 is laterally positioned between first leg 30 and second leg 32 of support bracket 18 . Because inboard brake shoe 12 , outboard brake shoe 14 and caliper 24 are laterally moveable relative to support bracket 18 and disc 16 , both inboard brake shoe 12 and outboard brake shoe 14 may clamp against disc 16 .
[0023] FIG. 4 depicts the interconnection of support bracket 18 and caliper 24 via second slide pin 22 . Second slide pin 22 is substantially similar to first slide pin 20 except that a bushing is not positioned between second slide pin 22 and caliper 24 . Second slide pin 22 extends along an axis 130 . Axis 130 is substantially parallel to axis 69 and axis 38 . Second slide pin 22 includes a body portion 132 slidably positioned within a bore 134 extending through boss 109 . Second slide pin 22 includes a tapered portion 136 and a threaded portion 138 . A drive recess 140 is formed in an end of second slide pin 22 opposite the end having threaded portion 138 . Slide pin bore 68 of support bracket 18 includes a tapered portion 142 and an internally threaded portion 144 . As previously described in detail with relation to first slide pin 20 , second slide pin 22 is installed by inserting a drive tool within drive recess 140 to threadingly engage threaded portion 138 with internal thread 144 . The second slide pin 22 continues to be rotated until tapered portion 136 of second slide pin 22 drivingly engages tapered portion 132 of pin aperture 68 . The portion of second slide pin 22 between the tapered interface and the threaded portion 138 is placed in tensile loading. Because tapered portion 136 is formed at an angle of 30 degrees relative to axis 130 , tapered portion 136 is wedged into engagement with tapered portion 142 of support bracket 18 . A mechanical interconnection is formed such that a force to remove second slide pin 22 from supply bracket 18 is greater than the force used to drive tapered portion 136 into engagement with tapered portion 142 of slide pin bore 68 . In this manner, second slide pin 22 resists vibratory loosening and/or a degradation in pin elongation during operation of disc brake 10 . An end cap 146 engages boss 109 to seal bore 134 from contamination. Cap 146 may be selectively removed to allow access to drive recess 140 .
[0024] With reference to FIG. 6 , it should be appreciated that first piston bore axis 113 and second piston bore axis 115 are positioned at a first radial distance X from laterally extending axis 38 . First slide pin bore axis 69 and second slide pin bore axis 130 are positioned at a radial distance Y from disc axis of rotation 38 . Distance Y is greater than distance X such that piston bores 110 and 112 are radially inward of slide pin bores 66 and 68 . The centerline of brake mounting apertures 64 are radially positioned from axis 38 a distance Z. In the embodiment shown in FIG. 6 , distance Y is approximately the same as distance Z. Lengths X, Y and Z need not maintain this relationship in other brake embodiments. It should also be noted that each of the piston bore axes, the slide pin bore axes and the centerlines of brake mounting apertures 64 are radially positioned within the circumference of disc 16 . This positioning provides a reduced brake envelope to assist in packaging the brake in a vehicle. Also, the arrangement provides a well balanced caliper for long term use.
[0025] Furthermore, the foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations may be made therein without department from the spirit and scope of the invention as defined in the following claims.
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The present invention relates to a disc brake operable to apply a clamping force to a rotatable disc. The disc brake includes a support bracket, slide pins coupled to the support bracket, inner and outer brake shoes and a caliper supported by the slide pins. The support bracket is a substantially rectangular frame defining a window. The window is adapted to accept a portion of a disc protruding therethrough. The support bracket includes a pair of spaced apart apertures extending through the frame where each aperture includes a threaded portion and a conical seat extending along an axis aligned to intersect the disc. The slide pins are threadingly engaged with a threaded portion. The slide pins do not extend through the window but protrude outwardly away from the window. Each slide pin has a tapered portion in engagement with one of the conical seats.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to pencils and, more specifically, to a process and formulation for a plastic pencil comprising a writing core, interlayer coating, a porous casing, coating and providing lining or striping on said coating.
2. Description of the Prior Art
There are other processes and formulations for producing pencils. While these formulations may be suitable for the purposes for which they where designed, they would not be as suitable for the purposes of the present invention as heretofore described.
It is thus desirable to provide a plastic pencil having a writing core and interlayer core housed within a porous casing having a coating that also provides for lining or striping on said coating.
It is further desirable to provide a plastic pencil having a formulation taken from the group of talcum powder, calcium carbonate, calcium stearate, low density polyethylene, palm oil, epoxy resin, styrene acrylonitrile and titanium dioxide and either graphite for black lead or coloring agent or pigment for colored lead.
SUMMARY OF THE PRESENT INVENTION
The present invention provides a plastic pencil comprising a writing core, a writing core coating, hereinafter referred to as the interlayer coating, a porous casing to enclose said writing core and said interlayer coating, a coating and lining or striping on the coating.
The writing core materials are weighed as per formulation and mixture of graphite (for black lead pencils) or color pigment or coloring agent (for color lead pencils), talcum powder, calcium carbonate, calcium stearate, low density polyethylene, palm oil, epoxy resin, styrene acrylonitrile and titanium dioxide is prepared as a batch. The batch is primarily mixed in a high speed mixer and compounded using co-rotating twin screw extruder and pelletized in form of free flowing pellets forming the writing core raw material.
The interlayer materials are a mixture of atactic polystyrene and Elvaloy®.
The casing materials are weighed as per formulation and a mixture of talcum powder, calcium sulfate, citric acid, calcium stearate, pigment or coloring agent, low density polyethylene, thermoplastic elastomer, Elvaloy®, atactic polystyrene and foaming agent is prepared in form of a batch. This batch is primarily mixed in a High speed mixer and compounded using co-rotating twin screw extruder and pelletized as free flowing pellets forming the raw material for the casing.
The coating and lining or striping materials is a mixture of atactic polystyrene and coloring agent.
The process of manufacturing the plastic pencils: comprises:
Drying the writing core formulation in a humidified air then automatically feeding the dried writing core into a lead extruder by vacuum loader;
Loading an interlayer extruder with the interlayer coating material formulation with both the lead extruder and interlayer extruder connected in a proprietary lead coating co-extrusion die-head;
Drying the casing material formulation in humidified air then automatically feeding the dried casing material into a casing extruder by vacuum loader;
Loading a coating extruder with the coating material formulation; and
Loading a lining extruder with striping or lining material formulation with the casing, coating and lining extruders connected to a proprietary pencil die-head.
The coating, lining, and casing extruders are initially started at a very low screw revolution. The material coming out of the pencil die-head is passed through a vacuum chamber consisting of pencil sizing unit and water cooling tank on the traction puller unit.
The lead and interlayer extruders are also started at a very low screw revolution. The lead along with the interlayer coating material is inserted into the pencil co-extrusion die-head.
The screw speeds of all the extruders are increased gradually until the desired size of the pencil is attained in the pencil sizing unit. The vacuum pump for the vacuum chamber is started and due to this vacuum the outer dimensions of the pencils are consistently maintained throughout the process of manufacturer.
The traction puller unit is fitted with a servo motor driven cutting system with an encoder measuring a predetermined length of pencil then signaling the servo motor, which engages the cutting system fly knife that continuously cuts pencils into a desired length with the cutting length being infinitely variable.
A primary object of the present invention is to provide a plastic pencil having a writing core, interlayer coating, a porous casing, coating and optionally providing lining or striping on said coating.
Another object of the present invention is to provide a plastic pencil having a writing core composition of talcum powder, calcium carbonate, calcium stearate, low density polyethylene, palm oil, epoxy resin, styrene acrylonitrile and titanium dioxide.
Yet another object of the present invention is to provide a writing core wherein said writing core composition further comprises graphite for a black writing core and color pigment or coloring agent for a colored writing core.
Still yet another object of the present invention is to provide a plastic pencil having an interlayer coating composition comprising atactic polystyrene and Elvaloy®.
An additional object of the present invention is to provide a plastic pencil wherein said interlayer core encompasses said writing core.
A further object of the present invention is to provide a plastic pencil having a porous casing composition of talcum powder, calcium sulfate, citric acid, calcium stearate, pigment or coloring agent, low density polyethylene, thermoplastic elastomer, Elvaloy®, atactic polystyrene and foaming agent.
A yet further object of the present invention is to provide a plastic pencil wherein said porous casing encompasses said interlayer coating and said writing core.
A still yet further object of the present invention is to provide a plastic pencil having a coating composition comprising atactic polystyrene and coloring agent.
Another object of the present invention is to provide a plastic pencil wherein said porous casing encompasses said interlayer coating and said writing core.
Yet another object of the present invention is to provide a plastic pencil having a lining or striping composition comprising atactic polystyrene and coloring agent and wherein said lining or striping is applied to said coating.
Additional objects of the present invention will appear as the description proceeds.
The present invention overcomes the shortcomings of the prior art by providing a process and formulation for a plastic pencil having a writing core, an interlayer coating encompassing said writing core, a porous casing encompassing said interlayer coating, a coating covering said porous casing and lining or striping on said coating.
The foregoing and other objects and advantages will appear from the description to follow. In the description reference is made to the accompanying drawing, which forms a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. In the accompanying drawing, like reference characters designate the same or similar parts throughout the several views.
The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawing in which:
FIG. 1 is a chart of the components embodying the plastic pencil of the present invention.
FIG. 2 is a chart depicting the writing core raw materials for the plastic pencil of the present invention.
FIG. 3 is a chart depicting the interlayer materials for the plastic pencil of the present invention.
FIG. 4 is a chart depicting the porous casing raw materials for the plastic pencil of the present invention.
FIG. 5 is a chart depicting the coating, lining and striping raw materials for the plastic pencil of the present invention.
FIG. 6 is a chart of the manufacturing process for the plastic pencil of the present invention.
FIG. 7 is a chart depicting the continuation of the manufacturing process for the plastic pencil of the present invention.
DESCRIPTION OF THE REFERENCED NUMERALS
Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, the Figures illustrate the plastic pencil of the present invention. With regard to the reference numerals used, the following numbering is used throughout the various drawing figures.
10 plastic pencil 12 writing core of plastic pencil 10 14 interlayer coating material of plastic pencil 10 16 porous casing of plastic pencil 10 18 coating material of plastic pencil 10 20 lining or striping material of plastic pencil 10
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following discussion describes in detail one embodiment of the invention (and several variations of that embodiment). This discussion should not be construed, however, as limiting the invention to those particular embodiments, practitioners skilled in the art will recognize numerous other embodiments as well. For definition of the complete scope of the invention, the reader is directed to appended claims.
Referring to FIG. 1 , shown is a chart of the components embodying the plastic pencil of the present invention. Shown are the constituent components formulated in the manufacturer of the plastic pencil 10 of the present invention.
Referring to FIG. 2 , shown is a chart depicting the writing core raw materials for the plastic pencil of the present invention. The present invention provides a writing core 12 consisting of a formulation composition comprising 0.1%-15% by weight of talcum powder, 0.1%-15% by weight of calcium carbonate, 5%-25% by weight of calcium stearate, 0.1%-5% by weight of low density polyethylene, 0.1%-5% by weight of palm oil, 0.1%-15% by weight of epoxy resin, 0.10%-40% by weight of styrene acrylonitrile and 5%-25% by weight of titanium dioxide with 40%-80% by weight of graphite added for black lead and 5%-25% by weight of color pigment or coloring agent for colored lead which are mixed in a high speed mixture. The color core raw materials are further compounded using a co-rotating twin screw extruder where then the mixture is extruded and pelletized into free flowing pellets thereby forming the writing core 12 .
Referring to FIG. 3 , shown is a chart depicting the interlayer coating of writing core raw materials for the plastic pencil of the present invention. The present invention provides an interlayer coating material 14 consisting of a formulation composition comprising 70-99% by weight of atactic polystyrene and 0.1-15% by weight of Elavloy®. The interlayer coating material 14 is placed in a hopper of an interlayer coating extruder. The interlayer coating extruder is connected to a lead extruder die.
Referring to FIG. 4 , shown is a chart depicting the porous casing raw materials for the plastic pencil of the present invention. The present invention provides a porous casing 16 consisting of a formulation composition comprising 10%-30% by weight of talcum powder, 0.1%-5% by weight of calcium sulfate, 0.1%-5% by weight of citric acid, 0.1%-5% by weight of calcium stearate, 0.1%-5% by weight of pigment or coloring agent, 0.1%-15% by weight of low density polyethylene, 0.1%-10% by weight of thermoplastic elastomer, 0.1%-10% by weight of Elavloy®, 25%-75% by weight of atactic polystyrene and 0.1%-2% by weight of foaming agent, which are mixed in a high speed mixer and compounded using a co-rotating twin screw extruder where then the mixture is extruded and pelletized into free flowing pellets thereby forming the porous casing 16 .
Referring to FIG. 5 , shown is a chart depicting the coating, lining and striping raw materials for the plastic pencil of the present invention. The present invention provides a coating material 18 and a lining material or a striping material 20 consisting of a formulation composition comprising 70%-99% by weight of atactic polystyrene and 0.1%-15% by weight of coloring agent. The coating material 18 is placed in a hopper of a coating extruder and the lining material or striping material 20 are placed in the lining or striping extruder hopper. The casing, coating and lining extruders are connected together in a specially designed pencil die head.
Referring to FIG. 6 and FIG. 7 , shown is the manufacturing process comprising the steps of: Drying the writing core 12 formulation in a humidified air then automatically feeding the dried writing core 12 into a lead extruder by a vacuum loader; Loading an interlayer extruder with the interlayer coating material 14 formulation with both the lead extruder and the interlayer extruder connected in a proprietary lead coating co-extrusion die-head; Drying the porous casing 16 material formulation in humidified air then automatically feeding the dried porous casing 16 material into a casing extruder by the vacuum loader. Loading a coating extruder with the coating material 18 formulation and loading a lining extruder with the lining material or striping formulation 20 with the casing, coating and lining extruders connected to a proprietary pencil die-head.
The coating, lining, and casing extruders are initially started at a very low screw revolution. The material coming out of the pencil die-head is passed through a vacuum chamber consisting of pencil sizing unit and water cooling tank (coupled with a chamber tank unit). The water is maintained at −10 degrees Celsius. The lead and interlayer extruders are also started at a very low screw revolution. The lead along with the interlayer coating material 14 is inserted into the pencil co-extrusion die-head.
The screw speeds of all the extruders are increased gradually until the desired size of the pencil is attained in the pencil sizing unit. The vacuum pump for the vacuum chamber is started and due to this vacuum the outer dimensions of the pencils are consistently maintained throughout the process of manufacturer.
The traction puller unit is fitted with a servo motor driven cutting system with an encoder measuring a predetermined length of pencil then signaling the servo motor, which engages the cutting system fly knife that continuously cuts pencils into a desired length with the cutting length being infinitely variable.
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 methods differing from the type described above.
While certain novel features of this invention have been shown and described and are pointed out in the annexed claims, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.
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.
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A plastic pencil comprising a writing core, an interlayer coating material placed about the writing core, a porous casing enclosing the interlayer coating material on the writing core and a covering applied to the exterior surface of the porous casing.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of and an apparatus for detecting the condition of a crack generated in a rotor of a rotary machine during an operation.
2. Description of the Prior Art
In recent years, as there is an increased demand for larger capacities of power plants such as thermoelectric power plants and nuclear power plants, the capacities of major equipments of these plants such as steam turbines, generators and so forth become larger. Therefore, any accident in the steam turbine or the generator may cause a serious problem such as an interruption of an electric power supply over a wide region or district.
In order to obviate such a problem, it becomes quite important that an abnormality occurring in the turbine or the like is detected at an early stage and a repair and that a replacement of parts be made promptly. The abnormality in such rotary machines is attributable to various causes and develops various symptoms among which an abnormal vibration of a motor of the rotary machine occurs most frequently and often causes serious accidents.
The abnormal vibration of the rotor is often caused by generation of a crack therein. Any crack generated in the rotor of a turbine or a generator tends to grow rapidly to cause a breakdown thereof, because such rotary machines are interrupted frequently in order to adjust a power supply in view of a load demand which varies according to seasons and even in a day.
Hitherto, the detection of the crack generated in the rotor has been made by a non-destructive inspection or the like measure at the time of a non-operation of the rotor, e.g. a fabrication of the rotor or a periodic inspection.
Some proposals have been made for detecting a crack in the rotor during the operation of the rotary machine. However, these proposals necessitate specific additional detecting devices which are generally expensive. Therefore, to provide for early detection of a crack in the rotor so as to avoid a serious accident in the rotary machine, it is necessary either to interrupt the operation of the rotary machine frequently to provide for non-destructive inspection of the rotor, or to provide the additional detecting devices for to the rotary machine. However, in the former case the rate of operation of the rotary machine is decreased. In the latter case the cost of the rotary machine is raised.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a method of and an apparatus for detecting the condition of a crack generated in the rotor without any interruption of operation of the rotary machine and without any specific additional detecting equipment.
To this end, according to an aspect of the present invention, there is provided a method for detecting a condition of a crack generated in a rotor of a rotary machine during operation thereof, in which the number of revolutions of the rotor and oscillations on journal end portions of the rotor born by the bearing are continually detected, and wherein the detection of the crack condition is conducted on the basis of a detected signal corresponding to the waveform of each half of at least one cycle of the detected rotor oscillations.
According to another aspect of the present invention, there is provided an apparatus for detecting a condition of a crack generated in the rotor of a rotary machine during the operation thereof, the apparatus comprising: first sensing means for sensing the number of revolutions of the rotor and adapted to output a trigger command; and second sensing means for sensing oscillations of journal end portions of the rotor born by bearings and adapted for outputting a signal corresponding to the detected oscillations; wherein the apparatus further comprises an analog-to-digital converting means adapted to start a digitization of the signal from the second sensing means in response to the trigger command coming from the first sensing means; an arithmetic unit for processing the digitized signal from the analog-to-digital converting means, and a display for displaying the results of the processing.
In general, when a crack is generated in a rotor, an abnormal vibration of the rotor takes place due to a cyclic change of a bending stiffness in one revolution of the rotor.
These and other objects, features and advantages of the invention will become clear from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an embodiment of the present invention applied to a power plant having a steam turbine;
FIG. 2 is a chart showing a waveform of the oscillation of the rotor;
FIG. 3 is a diagrammatical representation of a change of a bending stiffness occurring in one cycle of revolution of the rotor;
FIG. 4 is a flow chart of a process for detecting the crack;
FIG. 5 is a flow chart of a modified process for detecting the crack; and
FIG. 6 is an illustration of an example of judgement or evaluation of the crack condition in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, a power plant to which the present invention is applied has two steam turbines and a generator. The reference numerals 1 and 2 designate rotors of the steam turbines, respectively. The reference numeral 3 designates a rotor of the generator. The rotors 1, 2 and 3 are born at their journal portions by bearings 41 to 46. A reference numeral 5 designates a sensor for sensing the number of revolutions of the rotor 1 of the steam turbine. The sensor 5 is disposed adjacent to the bearing 41 bearing one of the journal portions of the rotor 1. The bearings 41 to 46 are provided with sensors 61 to 66 respectively, adapted for sensing the vibration of the journal portions of the rotors 1, 2 and 3 born by these bearings. The sensor 5 and the sensors 61 to 66 have been used conventionally to inform the operator of the conditions of the power plant.
The signals coming from the sensors 61 to 66 are delivered to a signal processor 6. The signal processor 6 delivers an oscillation signal So to an analog-to-digital converter 7 (A/D converter) in which the oscillation signal So is digitized. More specifically, in the A/D converter 7, the digitization of the oscillation signal So for a one cycle thereof is started by a trigger command Cst coming from the sensor 5, at a sampling number of 512 (=2 9 ) or 1024 (=2 10 ).
A detailed description will be made hereinafter as to the principle of judgement of the crack condition.
I. Relation Between Crack and Vibration
The full-line curve in FIG. 2 shows the oscillation waveform series detected by the sensor when the rotor is rotating at a constant speed while there is no progress in a crack generated in the rotor. However, when there is any progress in the crack, the oscillation waveform series is changed as shown by the broken line in FIG. 2. When there is any progress in the crack, the bending stiffness of a cracked portion of the rotor is changed during one cycle of the rotation of the rotor. This cyclic change of the bending stiffness is shown in FIG. 3 in an exaggerated manner for an easier understanding. In this regard, the bending stiffness or the flexural rigidity is defined as EI, where E is the modulus of elasticity or Young's modulus and I is the moment of inertia of the cross section. When the rotor takes such a position that the crack is directed upwardly, i.e. in the direction opposite to the direction of the gravitational force, as in the range A in which the crack tends to be closed, the bending stiffness of the rotor is substantially equal to that of the rotor EIo in the initial period of use of the rotor, i.e., acts like a rotor without a crack. Namely there is little change of the oscillation waveform. On the contrary, when the crack is directed downwardly, i.e. in the same direction as the gravitational force, as in the range B in which the crack tends to be opened or progressed, the bending stiffness of the rotor is expressed by (EIo-ΔEI) due to the bending stiffness loss (-ΔEI). This change of the bending stiffness causes an increase of static deflection which in turn changes the static equilibrium level. Namely, when the crack tends to be closed, an equilibrium level of the cracked rotor substantially coincides with the equilibrium level of the rotor in the initial period of use, e.g. in the state immediately after the installation thereof when there is no crack. On the other hand, when the crack tends to be opened, the equilibrium level of the rotor significantly differs from that in the initial period of use by a value δ, as will be seen from FIG. 2. In consequence, this difference causes a difference of the oscillation waveform between the rotor having any crack progress and the rotor in the initial period of use, i.e. the rotor having no crack progress. Namely, as will be seen from FIG. 2, the oscillation waveform of the cracked rotor (broken line) substantially coincides with that of the initial period of use of the rotor (full line) in the range in which the crack tends to be closed. The waveforms, however, do not coincide with each other in the range in which the crack tends to be opened.
II. Principle of Judgement
(1) One of the methods for detecting the crack condition is to compare the area of oscillation waveform. According to this method, the digitized oscillation signal Sdi coming from the A/D converter 7 is delivered to an integrator 10 in which areas Af and As (see FIG. 2) of each wave half of one whole cycle is calculated in accordance with the following formulae (1) and (2). ##EQU1## where, N is the sampling number.
If there is no progress in the crack, the first half part and the second half part of the oscillation waveform in a one cycle take substantially equal form as shown by the full-line curve, in the case where the rotor is rotating at a constant speed. Namely, there is a relationship expressed by Af=As. On the contrary, when there is any progress in the crack, the first half part and second half part of the waveform in a given cycle do not coincide with each other. More specifically, the areas Af and As take a relationship expressed by As/Af>1. Assuming here that the change in the waveform corresponds to the variance in the static deflection when a variance of 1 μm occurs at a speed of 3,000 r.p.m., the ratio of area is expressed by As/Af=1.015. Therefore, taking into account the measurement error and any possible influence of external noise, it is quite reasonable to judge that the crack is making a progress when the variance of the static deflection reaches 4 μm, i.e. when the ratio As/Af has come to take a value of about 1.06. Namely, although the ratio As/Af exceeding 1 (As/Af>1) is considered theoretically as an index or symptom of progress of the crack, it is reasonable and practical to judge that there is any progress in the crack when the ratio As/Af takes a value in excess of 1.06 (As/Af>1.06) (see FIG. 6). The process explained hereinbefore will be more fully understood referring to the full line flow shown in FIG. 1 and to the flow chart shown in FIG. 4.
(2) Hereinafter, an explanation will be made as to another principle of judgement. The process of this judgement is shown by broken line in FIG. 1 and in the flow chart shown in FIG. 5.
The digitized in oscillation signal Sd digitized the same manner as explained before in the A/D converter 7 is delivered to a subtractor 8. In advance of the delivery of the signal Sd, the signals detected by the sensors 61 to 66 in the initial period of use of the rotor, e.g. immediately after the installation of the steam turbine, are digitized the same manner as explained before and are memorized in the memory unit 9 as digitized reference signal Srf. The subtractor 8 determines a difference ΔSi between the digitized oscillation signal Sdi detected at a sampling moment t i and the digitized reference signal S rfi memorized beforehand, and the difference ΔSi is delivered to an integrator 10.
ΔS.sub.i =S.sub.di -S.sub.rfi (3)
If a crack is generated in the rotor during operation thereof or if a crack has made any progress from the state in the initial period of use of the rotor, an abnormal signal component is added inevitably to the reference signal S rf to become a state of ΔSi≠0, i.e. Srfi≠Sdi. The relationship between the oscillation waveforms of the signals Srf and Sd is shown in FIG. 2.
The integrator 10 then integrates the difference signal ΔSi for each wave half of a whole cycle of the signal Sd, so that integrated values I.V.f and I.V.s are obtained for the first wave half and for the second wave half, respectively, as follows. ##EQU2## where N is the sampling number.
As will be understood from the aforementioned description, when there is any progress in the crack of the rotor, the integrated value I.V.s takes a certain value although the integrated value I.V.f is almost zero. Namely, a ratio R=I.V.f/I.V.s takes an extremely small value. The value of the ratio R is then compared with a predetermined decision value β, which may be 0.95, for example.
Namely, it is judged that there is a progress in the crack, when the following condition is met.
R=I.V.f/I.V.s≦β
According to this second embodiment, it is possible not only to detect the progress of the crack at an early stage but also to know the degree of progress of the crack. Namely, in this embodiment, it is possible to detect the secular change in the crack condition by using the oscillation waveform detected immediately after the installation of the turbine as the reference waveform which is memorized in the memory unit and compared with the detected oscillation waveform. In addition, by substituting the newly detected oscillation waveform for the memorized reference waveform at each time of the detection, i.e. by using the waveform detected ΔT time before as the reference waveform, it is possible to known the rate or speed of progress of the crack during ΔT. Needless to say, it is necessary to change the predetermined decision value β according to the change of the reference waveform.
In the embodiments described hereinbefore, the judgement as to the progress of the crack is made on the basis of the waveform of one whole cycle. However, this is not exclusive. A judgement can be made with higher reliability if the judgement is made on the basis of the mean values of area Af, As or the integrated values I.V.f, I.V.s calculated at the basis of the waveform detected during several cycles.
(3) As still another embodiment, it is possible to judge whether the crack is making progress by comparing the value ΔSij with a predetermined reference value α.
Namely, it is judged that the crack has made a progress when the following condition is met.
ΔSij>α
This process is shown in FIG. 1 by a chain line.
(4) It is also possible to make the judgement by means of a square sum of the value ΔSij or by means of the peak value of the amplitude.
It is still possible to indicate the reference signal and the detected signal simultaneously on a display to permit the operator to make a judgement as to whether the crack has made any progress.
As will be understood from the aforementioned description, according to the present invention, it is possible to detect the progress of a crack in the rotor without interruption of the rotary machine. In addition, it is not necessary to employ any specific additional detection devices because the progress of the crack can be detected by making use of sensors which have been used ordinarily in such rotary machines. Therefore, the present invention can be applied to any type of rotary machine having various capacities advantageously.
Although the present invention has been described through specific terms, it is to be noted here that the described embodiments are only illustrative and various changes and modifications may be imparted thereto without departing from the scope of the present invention which is limited solely by the appended claims.
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Disclosed is a method for detecting the condition of a crack generated in a rotor of a rotary machine during an operation thereof to check whether the crack is developing or not. The number of revolutions of the rotor and oscillations of journal end portions of the rotor born by the bearings are continually detected. The detection of the crack condition is made on the basis of the detected signal corresponding to the waveform of each half of at least one cycle of the detected rotor oscillation. Disclosed also is an apparatus for carrying out the method.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/528,302, filed Aug. 29, 2011, which application is incorporated herein by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to a method and apparatus for the management of heterogeneous disparately located systems. In particular, the current invention is directed toward a method and apparatus which enables a framework for the command & control, situational awareness, operational management and other capabilities of the aforementioned systems.
[0004] 2. Background of the Invention
[0005] Currently deployed control segment management systems have delivered complex solutions to meet the warfighter requirements. The capabilities provided have been cutting edge, but have been implemented in such a way that stifles the expansion of such systems. The root of this problem is multifaceted, but can be summarized by the following architectural and operational flaws:
Undefined requirements for openness and externality lead to tightly coupled data layers between ground control segment and remote asset segments; effectively producing a long line of proprietary closed stovepipe systems. External interfaces extremely difficult to maintain due to the fluidity of interface definitions (ICD) and specifications between the ground control segment and the systems it is controlling. Often, these legacy systems do not allow for external vendors to bid or support existing legacy systems, leaving the customer with little to no choice but to continue to contract the incumbent. Software targeted to run on specific hardware limits the capabilities and extensibility of the over all system. Adding or modifying capability is impossible to accomplish on existing systems, causing the customer to deploy new capabilities on disparate systems. Integration with legacy interfaces is very expensive due to the inflexibility of the technologies used to develop them, as well as the tightly held grip invoked by the developing contractors with ownership to different segments of the system. Clunky and disparate user interfaces lead to poor and inefficient mission execution. Poorly thought out training infrastructure and cluttered operational views lead to long and expensive training cycles.
[0013] This method of providing multiple dedicated hardware systems and software applications has proven to have expensive long-run costs to develop, deploy, and support. In an effort to mitigate these trends, a roadmap outlines the proposed design for an open and extensible architecture built on the most current open standards.
SUMMARY
[0014] An aspect of the present invention may reside in a method for providing a presentation layer with a customizable user interface. In the method, a first presentation service is registered with a dynamic service registry using a first plugin application programming interface (API). A first visualization of first data from a first data model is presented to a user using the first presentation service registered with the dynamic service registry.
[0015] In more detailed aspects of the invention, a second presentation service may be registered with the dynamic service registry using a second plugin application programming interface (API). A second visualization of second data from a second data model may be presented to the user using the second presentation service registered with the dynamic service registry. The a second infrastructure service may be removed from the dynamic service registry by removing the second plugin application programming interface (API).
[0016] In other more detailed aspects of the invention, a first infrastructure service may be registered with the dynamic service registry using a third plugin application programming interface (API). The first data model may be populated with data from the first infrastructure service. Further, a second infrastructure service may be registered with the dynamic service registry using a fourth plugin application programming interface (API). A second data model may be populated with data from the second infrastructure service. The first data model may include second data, and the user may selectively hide the second data from the presentation of the first visualization.
[0017] Another aspect of the invention may reside in an apparatus for providing a presentation layer with a customizable user interface, comprising: a first registered presentation service that presents a first visualization of first data from a first data model to a user; and a dynamic service registry that registers the first registered presentation service using a first plugin application programming interface (API).
[0018] Another aspect of the invention may reside in an apparatus for providing a presentation layer with a customizable user interface, comprising: means for presenting a first visualization of first data from a first data model to a user; and means for registering the first registered presentation service using a first plugin application programming interface (API).
[0019] Another aspect of the invention may reside in a computer program product, comprising: non-transitory computer-readable storage medium, comprising: code for causing a computer to register a first presentation service with a dynamic service registry using a first plugin application programming interface (API); and code for causing a computer to cause a present a first visualization of first data from a first data model to a user using the first presentation service registered with the dynamic service registry.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 shows an outline of core framework itself consisting of multiple, interconnected open interface frameworks supporting multiple disciplines.
[0021] FIG. 2 shows the infrastructure framework which consists of the applications, messaging and data handling modules.
[0022] FIG. 3 shows the presentation framework.
[0023] FIG. 4 shows the plugin framework.
[0024] FIG. 5 shows the communications framework which consists of the services and packages that are designed to abstract hardware communications away from applications and expose their interfaces via standard SOA methods.
[0025] FIG. 6 shows the training framework which consists of the packages and modules that are designed to enable temporal control, feedback and scripting of system-wide events for training purposes.
DETAILED DESCRIPTION
[0026] In order to effectively address the aforementioned deficiencies inherent to currently deployed ground segment architectures, a comprehensive solution herein leverages open standards in order to create an open and extensible architecture. This architecture consolidates command & control (C2), situational awareness (SA), and operations management (OM) into one simple solution. The solution is implemented as a blend of the service-oriented architecture (SOA) and plugin architecture paradigms in order to allow for maximum extensibility as well as addition or removal of components. Leveraging off of this plugin and open-interface based architecture, targeted, specific applications can be built with little development effort. The user interfaces for this system should leverages off the 4-dimensional geospatial and temporal domains in order to provide the operators with true battle field and airspace awareness.
[0027] The solution for this common ground system architecture (CGSA) should be built on the notion of having the ability to perform command & control (C2), situational awareness (SA), and operations management (OM) for a generically defined remote asset or set of assets.
[0028] In order to effectively achieve the goal of having a common ground segment architecture, the solution needs to be architected in such a way as to effectively separate the core functionalities relating to the application framework away from the generic operational features (C2, SA, OM) relating to the interaction of the remote assets. Once implemented, these two loosely coupled layers will serve as the foundation for the integration of specific UAS systems, their sub-systems, and their related concepts of operation (CONOPS).
[0029] Moreover, the aforementioned core operational features (C2, SA, OM), should have the ability to be extended, augmented or complimented with other business applications in order to meet specific requirements for customer-specific solutions. For this reason, this core architecture should be implemented with open interfaces and API(s) allow the user community to develop custom-tailored solutions that conform to the core infrastructure. Having direct access to the core data modeling, utilities and infrastructure, the applications are limitless and highly extensible.
[0030] Core Framework
[0031] Currently deployed systems are very rigid, not allowing for effective extensibility and configurability. The modification of interfaces to these systems is expensive, especially if there are multiple systems involved in that interface. Adding functionality and/or systems requires modification to legacy systems and interfaces, which causes a ripple effect of impact to all systems involved. Oftentimes corners are cut or features are left out due to the integration cost of a small change.
[0032] Taking on the task of designing a core framework that is flexible, extensible and configurable requires a paradigm shift that involves the blending of two currently accepted architectural frameworks. First we take what is arguably the most flexible framework available today, the Service Oriented Architecture (SOA). SOA allows for the design of components and services to be fluid and ever changing, with little to no impact on external users of the system. In a nutshell, it provides optimum flexibility. Next we take the Plug-In framework that excels at extensibility and configurability by allowing the allocation interchangeable and expandable software units. Blending the flexibility of a SOA system with extensibility and configure-ability of a plugin system we reach our optimal solution with maximum flexibility, extensibility, and configurability.
[0033] FIG. 1 shows the an outline of core 100 framework itself consisting of multiple, interconnected open interface frameworks supporting multiple disciplines. As depicted, the core framework serves as a housing for multiple targeted frameworks each with their own key role in the overall architecture. The frameworks housed within the core framework include: the Infrastructure Framework, the Presentation Framework, the Plugin Framework, the Communications Framework, and the Training Framework.
[0034] Component Breakdown:
[0035] 101 —Presentation framework designed to be completely decoupled from any infrastructure and communication through open interfaces.
[0036] 400 —Training framework designed to be able to record, playback, script and interact with in during training scenarios.
[0037] 300 —Communications framework designed to abstract hardware device I/O from the core framework, exposing their interfaces via open standards (web services, etc).
[0038] 200 —The heart of the inter-communications and applications running withing the system.
[0039] Infrastructure Framework
[0040] The infrastructure framework should sit on top of a widely used and supported open source stack that's fully Java EE 5.0+ compliant. It should allow features to be swapped in and out without impacting the workflow of the system. Leveraging off of open source standards as well as best practices, the infrastructure should be built specifically to be an ever growing and changing set of capabilities without impacting the clients.
[0041] The application server concept allows for a highly scalable and manageable infrastructure core. The application server serves as a host for business processes in a managed environment that is highly scalable and portable. Components can be easily deployed or un-deployed, without impacting the deployment of a system as a whole and all business processes conform to the open standards set by the Java development standards. The application server monitors and controls data access, load balancing, failover, clustering, etc. Legacy systems often have to build these capabilities into each and every application, making maintenance extremely expensive and severely impacting the systems scalability.
[0042] The application can deployed on a single monolithic workstation or can be clustered and deployed on multiple dissimilar platforms to fit the customer requirements. The open source application server enables this capability out of the box, only requiring minor configuration settings for a change in development environment.
[0043] The application server can be complimented with the use of a data translation bus such as an ESB (Enterprise Service Bus), JCA (Java Connection Architecture) or advanced data modeling frameworks such as DDS (Data Distribution Service). The use of an data bus is critical to integrating a system with multiple, dissimilar data feeds. The data bus is designed to be the translation layer between the infrastructure and external interfaces. The advantages of using such a bus is that they contain built-in service units that enable the developer in most cases to not have to write a single line of code to integrate to a new or legacy interface. Using configuration files, connecting to external systems is no longer an expensive, time-consuming effort.
[0044] Data model and data distribution is the heart of the messaging passing through the infrastructure. The architecture supports a wide variety of data distribution techniques, all using the same publish/subscribe paradigm for flexible and configurable data flow. Two commonly used data distribution mechanisms are JMS and DDS, both of which are supported with the infrastructure. JMS is an open standard that allows for the infrastructure to easily integrate into any system who also conforms to this very widely used standard. DDS is a more robust, real-time data distribution mechanism which focuses on a data centric model rather than an event based model like JMS.
[0045] At the core of the infrastructure are the core data models. In order to keep from stove-piping the SOA system, everything must be open and extensible, including, and most importantly, are the data models. Data models are ultimately the contracts that clients will conform to. The infrastructure framework allows core data models to be defined and then extended as the customer sees fit. The core data models allow external interfaces with dissimilar interfaces yet similar types of data to be represented as a single global model. The advantages of these core extensible data models are very valuable. If an external interface changes, the rest of the system does not have to change to interface with this system. The data models change, but the interfaces stay the same. This is a huge cost savings as software systems are constantly evolving and tweaking interfaces. To keep the application compliant with these changes, configuration files need to be changed, but no software.
[0046] Component Breakdown:
[0047] 200 —Infrastructure framework which can consist of any number of application severs, messaging buses, translation services and database services.
[0048] 201 —Tactical core services meant to contain all of the underlying data translations, messaging and core, domain-agnostic services needed to support tactical data flow.
[0049] 202 —Tactical domain services contain all of the domain-specific services that are required as a framework for higher level applications.
[0050] 203 —Tactical application services are the first active level of complete applications built on top of the tactical core and domain services. These applications utilize both the core and domain services to accomplish tactical tasking.
[0051] 204 —Enterprise messaging bus, such as JMS or DDS, that enables inter module as well as external module communication and data model management. Messaging bus can be swapped in/out with any compliant messaging system.
[0052] 206 —Persistence framework designed to abstract the database interactions away from the business processes. Standard frameworks such as Hibernate can be utilized to help further the abstraction.
[0053] 207 —Persistent data, housed within any database (sql, derby, oracle, etc).
[0054] 208 —Data models. Core, common data models for all modules and system types. All external entity and/or asset data is converted into these data models and passed around the system as such so that when an external interface changes, the data models only need to be updated in one place.
[0055] 209 —Core Command and Control framework designed to abstract the standard workflow for sending commands or signals to an external entity as well as receiving responses from those entities.
[0056] 209 - 1 —API that gets registered within the service registry for all services and applications within the system to utilize.
[0057] 210 —3rd party service repository for tactical core services that can be injected into any defined workflow process.
[0058] 211 —The heart of the infrastructure service framework. A dynamic service registry (such as OSGi) that maintains a registry of all existing services as well as dispatches service requests between services.
[0059] 212 - 214 —Example domain services that will run on within the application server container. Examples include Operations management, Payload Management and Logistics management as well as their corresponding API's that are registered within the service registry.
[0060] 215 —Tactical core services APIs that are registered with the service registry as well as exposed via web-service based technologies for all services to access.
[0061] 216 —Tactical domain services APIs that are registered with the service registry as well as exposed via web-service based technologies for all services to access.
[0062] 217 —Tactical application service APIs that are registered with the service registry as well as exposed via web-service based technologies for all services to access.
[0063] 218 - 220 —Example tactical applications and services that will run on within the tactical applications layer. Examples include Tasking management and Collaboration management as well as their corresponding API's that are registered within the service registry.
[0064] 221 —External Entities—External entities that push, pull and receive data from the infrastructure framework. These entities are typical standard interfaces, such as LINK 16 as well as entities that are directly controlled via the infrastructure framework, such as an air vehicle asset.
[0065] 222 - 224 —External entities tapping into the data contents of the infrastructure for further processing or visualizations. Typical example would be a presentation layer visualizing the data contents.
[0066] 225 —Service registry communications. Standard, open communications to register, lookup and directly task services that are registered within the registry.
[0067] 226 —Data model/Data bus communications to subscribe or publish to the data model management services.
[0068] 227 —Inter-Package communication, using open, web-service based protocols as well as service registry protocols.
[0069] Sample Use Case(s):
[0070] Receive incoming data from 209 external entities:
[0071] 1. Data received via a standard link (LINK 16 ).
[0072] 2. Data is translated into the solution data model format 204 .
[0073] 3. Data is passed to the 204 enterprise messaging system to be dispatched the appropriate entity.
[0074] 4. 206 Database services receive incoming 204 data, 206 persist as necessary and 226 alert the system of the new data changes.
[0075] 5. 202 - 203 Subscribed enterprise applications receive data and process accordingly.
[0076] Presentation Framework
[0077] The application presentation framework is built off of multiple, widely used and supported open source presentation technologies: NASA WorldWind Java and Java FX. The presentation framework consists of a layer management component, services layer component, data model management and a plugin management framework.
[0078] Building on top of the open source Java world wind core capabilities, we have implemented a layer management framework to allow for highly customizable user interface. The help reduce clutter and give the user the ability to see only the data he needs, the layer management component allows the user to selectively show/hide any items they chose.
[0079] The presentation layer is completely decoupled from any single infrastructure. The presentation layer connects to external systems via open interfaces (services, JMS, DDS, etc) and populates its local data models accordingly. The services components use open contracts (WSDLs, JMS, XML) to communicate with an infrastructure that allows the presentation layer to quickly integrate into legacy infrastructures or used to augment current presentation systems. This allows the customers to not be tied to a single presentation layer and/or infrastructure, adding or removing presentation components as necessary.
[0080] Similar to the infrastructure, the presentation has a set of core data models that can either be shared with the core infrastructure or independently extended based on customer need. Since the presentation layer can be used without the infrastructure, the core data model concept as described in the infrastructure is applied to the presentation layer as well. The data model layer provides open interfaces to populate and augment the core data models with external data, leaving little to software development needed for integrating with external or third party data feeds.
[0081] 102 —Adapter layer designed to house external communications adapters that abstract away the details about the protocols and messaging formats from the rest of the presentation layer.
[0082] 103 —Module layer which is designed to configure the adapter layer communications and further filter and abstract the data messaging protocols and formats away from the rest of the presentation layer.
[0083] 104 —Proxy layer is a dispatch layer where proxies can be created to filter and distribute data more efficiently.
[0084] 105 —Plugin layer is the visualization layer where components can be added to any visualization service and communicate directly with the proxy layer (or any other layer) to receive its data.
[0085] 106 - 108 —Example adapters that can be created to communicate with ANY external entity.
[0086] 106 - 108 - 1 —APIs for the adapters to register themselves with the service registry for all to see.
[0087] 109 —Core adapter API that all adapters must implement to properly be managed and discovered within the system.
[0088] 110 - 115 —Example Modules designed to configure the adapters and filter the data. These modules come standard with any tactical installation.
[0089] 116 —Container for extensible 3rd party modules to live along side of or replace existing modules.
[0090] 117 —Core module API that all modules must implement to properly be managed and discovered within the system.
[0091] 118 - 123 —Example proxies designed to abstract away the communications details from the presentation layer and filter the data. These proxies can come standard with any tactical installation.
[0092] 124 —Container for extensible 3rd party proxies to live along side of or replace existing proxies.
[0093] 125 —Core proxy API that all proxies must implement to properly be managed and discovered within the system.
[0094] 126 —Core plugins available for all tactical systems.
[0095] 127 —Container for extensible 3rd party plugins to live along side of or replace existing plugins.
[0096] 128 —Core plugin API that all plugins must implement to properly be managed and discovered within the system.
[0097] 129 —Service registry communications to register, look-up as well as task core registered services.
[0098] 130 —Service registry communications to register, look-up as well as task all services and applications within the system.
[0099] 131 —The starting point for the application is a service registration component to allow all components of the application to communicate with each other.
[0100] 132 —The service manager and its api designed to manage and monitor the services and system communications as well as provide services for others to query and listen for service events.
[0101] 133 —Core visualization components.
[0102] 134 —Generic layout management services for all components to use.
[0103] 135 —Plugin manager controls loading and unloading of plugins.
[0104] 136 —Extensible container for 3rd party visualization services.
[0105] 137 —Core GIS Services provided for all components to use.
[0106] 138 —Core Widget services provided for all components to use.
[0107] 140 - 141 —Any External entity that communicates directly with the adapters via any communication protocol.
[0108] 142 - 144 —Open, extensible communications between any entity and the adapter layer.
[0109] Plugin Framework
[0110] The plugin framework is what enables the presentation layer to be truly extensible. Through this framework developers have the ability to add their own data visualizations to the application, by creating new layers to be placed on an visualization surface. The API provided is extremely open and allows for the introduction of any custom graphical element that may be displayed within the application. The API also allows developers to quickly establish connections to external data sources which the plugin can then act on. This enables the customer to develop capabilities on the fly as needed as well as allowing for the application to be quickly extended given customer requirements. Plugins are highly configurable and can be built to enable new 3D modeling capabilities or something as simple as a new status widget. The plugins can also be added/removed dynamically without having to recompile or redeploy the system.
[0111] The plugin paradigm is a perfect complement to a SOA system. Not only is the entire presentation layer replaceable, but the internals of the presentation are also interchangeable. This allows for new technologies to be integrated quickly into the displays without having to rewrite the core infrastructure.
[0112] Plugin Drawing:
[0113] 1: The plugin which will be developed by the client. The only access to the Plugin Framework is via the provided API, which will allow clients to create custom graphics and connect to external services.
[0114] 2. Allows clients to extend the WorldWind layer construct to add their own layers to the globe.
[0115] 3. Allows clients to easily connect to external data sources via a JMS interface.
[0116] All that must provided is the location of the JMS service and the framework will handle retrieving the data.
[0117] 4. If the plugin has settings that should be able to be managed by the user, this module allows clients to specify them. The settings will be automatically displayed as JavaFX widgets on the main application menu.
[0118] 5. If the plugin has any tools that must be made available to the user, this module will allow them to be created and displayed on the main application window as JavaFX widgets.
[0119] 6. Provides an easy mechanism to display 3D data on the globe. Users need not write custom code to put 3D objects on the globe unless some custom mechanism is desired.
[0120] Communication Framework
[0121] The communication framework is designed to allow for quick integration with hardware components (radios, links, etc). The framework exposes all the hardware interfaces as SOA-compatible services to the rest of the infrastructure so that no internal clients need to be aware of the specific hardware implementation of a communication link, for example. Low level hardware drivers and interface changes are abstracted away so a change in communications hardware doesn't result in a ripple effect of changes in all parts of the infrastructure and even presentation layer.
[0122] The communications framework exposes open contracts to the rest of the system so that any SOA-compatible service or system can quickly integrate, control and communicate with the hardware. In a world where the hardware changes just as frequently as the software, the communications framework enables the customer to be flexible in their choice of hardware without having to worry about upgrading or replacing hardware components of the system.
[0123] Component Breakdown:
[0124] 300 —Communications Framework—Built as a SOA compatible set of modules, this framework can be added or removed from any SOA container.
[0125] 301 —Service Layer: The open, web-service based set of services designed to expose the hardware interface to the rest of the applications.
[0126] 302 —Data translation module. Translates hardware messages into SOA compatible messaging formats.
[0127] 303 —Device manager—Container for device specific drivers and proprietary protocols. New devices can be added/remove from this manager with no impact to the rest of the communications framework.
[0128] 304 —Device Modules—Self-contained modules that contain the specific details, messaging patterns and protocols for talking to specific hardware devices.
[0129] 305 —Protocol manager—Designed to abstract common protocols away from each of the devices and the infrastructure so there is a standard pool of protocol software for all devices to use. Example standards would include things like TCP/IP, 1553 , ARINC 249 , etc.
[0130] 306 —External Hardware device. Any localized hardware device that requires specific protocol and/or drive to communicate with the solution core.
[0131] 307 —Hardware specific I/O (TCP/IP, etc).
[0132] 308 —Open standard communication between the service layer and infrastructure framework.
[0133] Sample Use Case(s):
[0134] Communications with a 1553-based hardware device.
[0135] 1. External device connects to the protocol manager, which designates a connection (port, etc) for the device to operate on.
[0136] 2. Protocol manager decides the type of device and instantiates one or many device modules that contain the specific details on the messages for each of the devices.
[0137] 3. Device manager utilizes the data translation services to convert the proprietary hardware-specific messages into the solution core data model formats.
[0138] 4. Service layer transmits the solution core data models to the infrastructure framework for any further processing, if necessary.
[0139] Training Framework
[0140] The training framework is built into all components of the system. The training framework enables logging and playback abilities for all data feeds, scripted simulation mode as well as on the fly training all in one system.
[0141] By recording very fine details of how the system is being used, the operators can playback their missions, see where they could have done things differently or where things were done well.
[0142] The system is integrated with a number of simulation elements that allow the user to view and control assets or other systems just as if they were using the deployed system. The infrastructure doesn't make a distinction between the data feeds (simulated, real) so the transition between training and deployment is seamless.
[0143] Instructors can script scenarios in the framework and watch the play out on the system and monitor the user's interactions. They system can be paused and moved backwards or forwards in time, allowing a user to re-try or skip scenarios.
[0144] Component Breakdown:
[0145] 400 —Training framework—Built as a SOA compatible set of modules, this framework can be added or removed from any SOA container.
[0146] 401 —Temporal control module—Designed to expose and control time based responses, actions and data dissemination to the infrastructure framework.
[0147] 402 —Event Engine—Designed to produce and consume significant events that occur within the system to either store them for later playback or produce them during playback.
[0148] 403 —Looped communications between all engines, controlled via the temporal control module.
[0149] 404 —Service Layer—The open, web-service based set of services designed to expose the training interfaces to the rest of the applications.
[0150] 405 —Simulation Engine—Plug-able simulations that enable simulation and emulation of dynamic external interactions (e.g. air vehicle, satellite, etc).
[0151] 406 —Script Engine—Designed to allow for scripted play of system interactions.
[0152] 407 —Training persistence data—Persistence data required for playback and script execution. Persistence data can be configured to come from any set of databases, such as real-time flight logged data.
[0153] 408 —Open standard communication between the service layer and infrastructure framework.
[0154] Sample Use Case(s):
[0155] Replay of Mission:
[0156] 1. Training framework is set to playback from a flight logged database.
[0157] 2. Temporal control modules start the engine loops, setting for real time playback.
[0158] 3. Script engine retrieves logged data, parses and feeds to the event engine for processing.
[0159] 4. Event engine pushes the messages, via the service layer to the infrastructure for further processing.
[0160] 5. event engine pushes the messages to the simulation engine
[0161] 6. simulation engine determines if the messages require emulation or simulations of external entities, pushes messages to the service layer if necessary, otherwise it closes the loop back with the script engine to read the next set of temporal messages.
[0162] Situational Awareness
[0163] The Situational Awareness (SA) solution is designed to give the user a complete asynchronous, real-time, operational view. The SA solution contains several modular plugin to allow the user to view real-time status of any given asset that the system is connected to. From real-time asset monitoring and tracking to predictive modeling of asset future as well as reviewing of asset history.
[0164] The SA solution is capable of displaying and manipulating status data from multiple dissimilar assets in a single operational view. The system has the capability to show and maintain status in a 4 dimensional set of next generation user interfaces that is highly configurable and extensible. The SA solution provides tools and utilities to manipulate real time and offline data for real-time analysis using the latest in graphing and charting capabilities.
[0165] Based on the SOA infrastructure and plugin based presentation architecture, the SA solution is highly configurable and extensible. As new assets or sets of data are available to view, the SA solution will pick up on these data feeds and display the information for the user. In addition, the user can extend the SA solution by adding their own SA interfaces, 3D models, data sources, etc, with little to no development effort.
[0166] The SA solution is intended to bring together all of the dissimilar systems in one common operational picture.
[0167] Command & Control
[0168] Command and Control (C2) can take on many forms and traditionally requires every system to have their own specific command and control set of interfaces. The C2 solution is designed to break the paradigm of using multiple C2 systems for multiple assets. The C2 Solution is built on top of the SOA framework and in fact is seamlessly weaved into the infrastructure. The C2 solution provides a set of services that enable any and all systems to easily integrate their systems C2 messaging into the C2 solution.
[0169] The C2 solution meshes together common commands that are typically seen across multiple dissimilar systems as well as gives the user the ability to extend from these common command sets and integrate their specific command and control interfaces. This enables the community to essentially integrate any legacy and future systems into the C2 infrastructure.
[0170] Operationally, the C2 solution is meant to be the single command and control interface for all asset types. From airborne assets to unmanned sea assets, the C2 solution not only provides the capability to integrate with each specific systems proprietary command structure, but it also provides a visual interface that is capable of viewing and dispatching command sets via a common set of controls. Combining all of these capabilities not only provides a compact solution for any system, it also reduces maintenance and training costs.
[0171] Operations Management
[0172] The Operations Management (OM) solution is designed to allow for operational planning, re-planning and dynamic tasking of assets. OM is traditionally done with individual systems, using 2D charting and graphic capabilities. The OM solution is built on top of the solution SOA framework and contains a set of services and applications enable the user to perform all the necessary tasks for operations management.
[0173] The OM solution contains services to aide in operational route planning, analysis and report generation. The OM solution also allows the users to update the operational plans in real time, publishing the updated routing or tasking information directly to an asset or set of assets.
[0174] Using innovative 4D user interfaces, operationally the system can be deployed and configured to manage the missions or operations of multiple dissimilar assets. In addition, since the OM solution is built on top of the SOA framework, it has the capability to be extended and augmented with other key services.
[0175] The OM solution will provide a common interface and set of services for all system and asset types, dramatically reducing the systems needed to deploy any particular asset.
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The solution described herein, through it's unique design, provides capability such as command and control, situational awareness, operations management, and other tactical capabilities as building blocks to be added or extended for the buildout of specific strategic or tactical solutions. Traditional approaches for the implementation of strategic or tactical systems have historically been stove-piped and build on closed architectures. The solution is architected using open-standards and open-interfaces in order to simplify the integration into both new and legacy system.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and benefit of Korean Patent Application No. 2003-39959 filed on Jun. 19, 2003 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference.
BACKGROUND
[0002] (a) Field
[0003] The present invention relates to a secondary battery, and more particularly, to a structure of a safety valve in a secondary battery.
[0004] (b) Description of the Related Art
[0005] A secondary battery is a rechargeable battery that can be made into a smaller size or a larger size. Common types of secondary batteries include the nickel-hydrogen battery, the lithium battery and the lithium-ion battery. Depending on the external shapes, they may be classified into cylindrical type batteries and square type batteries.
[0006] Generally, the secondary battery includes a power generating element, that is, an electrode assembly having a positive plate, a negative plate and a separating plate, and a metal container receiving the electrode assembly and electrolyte, and a cap assembly fixed onto the opening of the container to seal the container.
[0007] Depending on the structure of the secondary battery, the cap assembly can be made in various forms, one of which has a cap plate welded onto the opening of the container to seal the container, a terminal pin, and a gasket insulating the cap plate from the terminal pin.
[0008] The terminal pin is welded onto a negative tap that is drawn out from the negative plate so that the terminal pin functions as a negative terminal.
[0009] Furthermore, a positive tap drawn out from the positive plate is electrically connected directly to the bottom of the cap plate or to the inner wall of the container to make the whole outside of the battery except the terminal pin function as a positive terminal.
[0010] Meanwhile, a secondary battery has a safety valve in order to prevent the battery from exploding by reducing the internal pressure when gases are generated in the battery and the internal pressure increases to a level higher than a prescribed level.
[0011] A conventional safety valve is either formed as an integrated structure of the cap plate or the container through mechanical, etching or electroforming process, or formed as a separate structure attached on the cap plate or the container.
[0012] Therefore, conventionally a safety valve must be provided separately to a secondary battery for its safety, and consequently it is necessary to add more process and equipment, which reduces the productivity (increase of complexity of process and manufacturing costs) of a secondary battery.
SUMMARY
[0013] In one embodiment of the present invention, a secondary battery is provided having a safety valve that is formed without a separate additional process. In another embodiment, a method of manufacturing a secondary battery is provided having a safety valve that is formed without a separate additional process.
[0014] In another embodiment, a secondary battery having an electrode assembly includes a positive plate, a negative plate and a separating plate interposed between those two plates, a container receiving the electrode assembly inside thereof, a cap plate fixed to an opening of the container to seal the container, and a safety valve formed on the region where the container and the cap plate are joined.
[0015] In this embodiment, the container and the cap plate are joined by welding, and the safety valve is formed on a sealing part where the container and the cap plate are sealed. The sealing part includes a first sealing part formed with a certain welding strength, and a second sealing part formed with a weaker welding strength than the first sealing part. The second sealing part forms the safety valve.
[0016] The sealing part includes a pair of long edges and a pair of short edges, and the safety valve can be formed on at least one of the long edges, and is formed with a length that is equal to or less than 30% of L, where L is the whole length of the long edge. Also, a length (l) can be formed to be 5 mm and 20 mm, where the length (l) is the length of the safety valve.
[0017] In one embodiment, the sealing part includes a pair of long edges and a pair of short edges, and the safety valve can be formed on at least one of the short edges. In another embodiment, the safety valve can be formed on the corners that are formed between the long edges and the short edges.
[0018] The container may be formed in a square or a cylindrical shape.
[0019] Also, a method of manufacturing a secondary battery according to one embodiment of the present invention includes a method of manufacturing a square secondary battery having a safety valve that is to be exploded to reduce the internal pressure when the internal pressure of the battery reaches a level higher than a predetermined level. A low sealing part functions as the safety valve by forming the low sealing part on a portion of a sealing part with a weaker welding strength than the other portion. The welding strength can be controlled when the sealing part is formed by welding a cap plate onto an opening of a square shaped container.
[0020] Also, a method of manufacturing a secondary battery according to another embodiment of the present invention includes a method of manufacturing a cylindrical secondary battery having a safety valve that is to be exploded to reduce the internal pressure when the internal pressure of the battery reaches a level higher than a predetermined level. A low sealing part functions as the safety valve by forming the low sealing part on a portion of the sealing part with a weaker crimping strength than the other portion. The crimping strength can be controlled when the sealing part is formed by crimping a cap plate onto an opening of a cylinder shaped container.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] [0021]FIG. 1 is a partial exploded perspective view of a secondary battery according to the first embodiment of the present invention.
[0022] [0022]FIG. 2 is a front view of a secondary battery according to the first embodiment of the present invention.
[0023] [0023]FIG. 3 is a partial perspective view illustrating a sealing part of a secondary battery according to the first embodiment of the present invention.
[0024] [0024]FIG. 4 is a partial perspective view illustrating a sealing part according to another embodiment of the present invention.
[0025] [0025]FIG. 5 is a partial perspective view illustrating a searling part according to yet another embodiment of the present invention.
[0026] [0026]FIG. 6 is a partial perspective view illustrating a secondary battery according to still yet another embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0027] Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
[0028] [0028]FIG. 1 is a partial exploded perspective view of a secondary battery according to the first embodiment of the present invention, and FIG. 2 is a side view of the FIG. 1 in an assembled form.
[0029] Referring to the drawings, a secondary battery according to an embodiment of the present invention includes a container 10 with an opening 12 on one side, an electrode assembly 20 that is inserted into the container 10 through the opening 12 , and a cap assembly 30 fixed to the opening 12 of the container 10 to seal the container 10 .
[0030] The electrode assembly 20 is formed with a positive plate 22 , a negative plate 24 and a separating plate 26 . According to an exemplary embodiment of the present invention, as shown in FIG. 1, the electrode assembly 20 in a form of a jelly roll can be used that is formed by stacking and winding the positive plate 22 , the negative plate 24 and the separating plate 26 .
[0031] The negative plate 24 includes a negative collector of a thin metal plate in a strip form, and a thin copper plate can be used as the negative collector. On at least one side of the negative collector is formed a negative coating portion that is coated with a negative metal composite comprised of a negative active material.
[0032] Also, the positive plate 22 includes a positive collector of a thin metal plate in a strip form, e.g., a thin aluminum plate. On at least one side of the positive collector is formed a positive coating portion that is coated with a positive metal composite with a positive active material.
[0033] On the upper part of the electrode assembly 20 are drawn out a positive tap 28 and a negative tap 28 ′ that are electrically connected to the positive plate 22 and the negative plate 24 respectively. A thin nickel plate can be used as a negative tap 28 ′, and a thin aluminum plate can be used as a positive tap 28 , but are not limited thereto. The positive tap 28 and the negative plate 28 ′ can be arranged in an opposite way to that in FIG. 1.
[0034] Meanwhile, the container 10 can be made of a metallic material with a shape of an approximate hexahedron, and so the container, itself, can function as a terminal. According to an embodiment of the present invention the container 10 can be made of aluminum or aluminum alloy that is light and conductive metal. Also, the container 10 has an opening 12 on one side, through which the opening the electrode assembly 20 can be inserted into the container 10 .
[0035] The container 10 can be formed in a square shape the corners of which are angled. Although it is not shown in the drawing, the angled corners can also be formed in a rounded shape.
[0036] The cap assembly 30 is placed on the opening 12 of the container 10 to seal the container 10 , and the cap assembly 30 has a cap plate 32 that is welded directly onto the opening 12 of the container 10 . The container 10 and the cap plate 32 can be made of the same metallic material to make the welding easier.
[0037] The cap assembly 30 has a terminal pin 36 which goes through the cap plate 32 while insulated by the gasket 34 . An insulating plate and a terminal plate (not shown in the drawing) are added on the lower part of the terminal pin 36 to insulate the terminal pin 36 from the cap plate 32 . The negative tap 28 ′ is welded onto the lower part of the terminal pin 36 so that the terminal pin 36 can function as a negative terminal.
[0038] Meanwhile, the positive tap 28 that is drawn out of the positive plate 22 is connected electrically directly to the bottom of the cap plate 32 or to the inside of the container 10 , and thereby, the outside of the whole battery except the terminal pin 36 can function as a positive terminal.
[0039] However, the structure of the positive terminal and negative terminal is not limited only to that explained above, and the structure of the positive terminal, like the structure of the negative terminal, can be formed through a separate terminal pin. Also, other structures can be applied thereto.
[0040] After the electrode assembly 20 is inserted into a container 10 , a protection case 38 made of an insulating material can be placed between the electrode assembly 20 and the cap assembly 30 to fix the electrode assembly 20 more firmly.
[0041] Furthermore, after welding the cap assembly 30 onto the opening 12 of the container 10 , electrolyte is injected through an electrolyte injection hole 40 on the cap plate 32 , and then it is sealed with a plug (not shown in the drawing).
[0042] For the square secondary battery with the above described structure, the cap plate 32 is welded onto a portion of the container 10 around the opening 12 by the seam welding method, and in an embodiment of the present invention, a sealing part (SP), i.e., the welded portion between the cap plate 32 and the container 10 , that comprises a first sealing part of a high sealing part (HSP) with a certain predetermined welding strength, and a second sealing part of a low sealing part (LSP) with a less welding strength than the first sealing part.
[0043] In order to differentiate clearly the high sealing part (HSP) and the low sealing part (LSP) in FIG. 2, the HSP is marked with a solid line and the LSP is marked with a dotted line.
[0044] The low sealing part (LSP) functions as a safety valve (SV) that is to explode to reduce the internal pressure in the container 10 when the internal pressure increases at a level higher than a prescribed level.
[0045] Accordingly, the low sealing part (LSP) of this embodiment of the present invention is formed with such a welding strength that the low sealing part explodes when the gas pressure reaches a level higher than 12 kgf/cm 2 .
[0046] Also, the high sealing part (HSP) is formed with such welding strength that the high sealing part withstands a pressure of around 20 kgf/cm 2 as an ordinary situation.
[0047] Formation of such a sealing part (SP) can be achieved by welding the cap plate 32 onto the opening 12 of the container 10 with a lower welding strength by controlling the welding strength on a certain region (the region of the low sealing part).
[0048] The safety valve (SV) of this embodiment of the present invention, as shown in FIG. 3, can be formed on at least one of the long edges when the sealing part (SP) is formed with a combination of a pair of long edges and a pair of short edges.
[0049] In this case, when the length of a long edge is L, a length (l) of the safety valve is to be less than 30% of L. In detail, the length (l) is to be less than 1 cm, preferably to be formed within the range of 0.1 to 10 mm.
[0050] [0050]FIG. 4 and FIG. 5 are modified examples of the embodiment previously described. FIG. 4 is an example where the safety valve is formed on at least one of the short edges of the sealing part (SP), and FIG. 5 is an example where the safety valve is formed on the corners of the sealing part (SP).
[0051] Up to now, the examples have been explained where the safety valve (SV) is formed with the low sealing part (LSP) by a welding process. However, in another embodiment of a secondary battery in a cylindrical shape that is made by a crimping process to seal the cap plate and the container, the low sealing part can be formed by controlling the crimping strength process.
[0052] [0052]FIG. 6 is a partial perspective view of a secondary battery in a cylindrical shape according to another embodiment of the present invention.
[0053] In the secondary battery in a cylindrical shape, a cap plate 32 ′ and a cap 10 ′ in a cylindrical shape is normally sealed by a crimping process. The secondary battery of the embodiment of the present invention has a low sealing part (LSP) that is crimped with a lower crimping strength on a certain region than the other region of the sealing part where the cap plate 32 ′ and the cap 10 ′ are sealed. The HSP (not shown in the drawing) is a high sealing part that is crimped with a higher crimping strength than the low sealing part (LSP).
[0054] Consequently, when the internal pressure increases at a level higher than a prescribed level, for example 12 kgf/cm 2 , the low sealing part (LSP) functioning as a safety valve explodes, and thereby the internal pressure is reduced to prevent the battery from exploding.
[0055] Also, according to another embodiment of the present invention, by controlling the welding strength or the crimping strength on the low sealing part that functions as a safety valve at a desired level, an effect can be attained to set the operating pressure more easily and more precisely.
[0056] As explained above, because the present invention can form a safety valve without an additional separate step for the sealing process of a cap plate and a container, a simpler manufacturing process and manufacturing cost saving can be realized.
[0057] Although embodiments of the present invention have been described in detail hereinabove in connection with certain exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiment, but, on the contrary is intended to cover various modifications and/or equivalent arrangements included within the spirit and scope of the present invention, as defined in the appended claims.
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An electrode assembly includes a positive plate, a negative plate and a separating plate interposed between those two plates, a container receiving the electrode assembly inside thereof, a cap plate fixed onto an opening of the container to seal the container, and a safety valve formed on the region where the container and the cap plate are joined.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of co-pending U.S. patent application Ser. No. 12/635,143, filed Dec. 10, 2009, which is a continuation-in-part of co-pending U.S. patent application Ser. No. 12/635,025, filed Dec. 10, 2009, which is related to other applications as follows: a continuation-in-part of U.S. patent application Ser. No. 12/469,312, filed May 20, 2009, now U.S. Pat. No. 7,998,002 which is a continuation-in-part of U.S. patent application Ser. No. 12/469,258, also filed May 20, 2009, now U.S. Pat. No. 7,963,863 which is a continuation-in-part of U.S. patent application Ser. No. 11/829,461, filed Jul. 27, 2007, now U.S. Pat. No. 7,537,530, which is a continuation-in-part of U.S. patent application Ser. No. 11/772,903, filed Jul. 3, 2007, now U.S. Pat. No. 7,537,529; further a continuation-in-part of U.S. patent application Ser. No. 12/492,514, filed Jun. 26, 2009, now U.S. Pat. No. 8,025,594; still further a continuation-in-part of U.S. patent application Ser. Nos. 12/558,732 and 12/558,726, filed Sep. 14, 2009, which are continuations of U.S. patent application Ser. No. 12/186,877, filed Aug. 6, 2008, now U.S. Pat. No. 7,803,069 which is a continuation of Ser. No. 11/832,197 now U.S. Pat. No. 7,410,429, filed Aug. 1, 2007, now U.S. Pat. No. 7,410,429 which is a continuation-in-part of Ser. No. 11/829,461 now U.S. Pat. No. 7,537,530, filed Jul. 27, 2007, which is a continuation-in-part of Ser. No. 11/772,903 now U.S. Pat. No. 7,537,529, filed Jul. 3, 2007. The entire disclosure of each of these references is hereby incorporated herein by reference.
FIELD OF THE INVENTION
The present invention generally relates to golf balls and more particularly is directed to golf balls having multi-layered cores comprising a hardness gradient within each core layer as well as from core layer to core layer.
BACKGROUND OF THE INVENTION
Golf balls have conventionally been constructed as either two piece balls or three piece balls. The choice of construction between two and three piece affects the playing characteristics of the golf balls. The differences in playing characteristics resulting from these different types of constructions can be quite significant.
Three piece golf balls, which are also known as wound balls, are typically constructed from a liquid or solid center surrounded by tensioned elastomeric material. Wound balls are generally thought of as performance golf balls and have a good resiliency, spin characteristics and feel when struck by a golf club. However, wound balls are generally difficult to manufacture when compared to solid golf balls.
Two piece balls, which are also known as solid core golf balls, include a single, solid core and a cover surrounding the core. The single solid core is typically constructed of a crosslinked rubber, which is encased by a cover material. For example, the solid core can be made of polybutadiene which is chemically crosslinked with zinc diacrylate or other comparable crosslinking agents. The cover protects the solid core and is typically a tough, cut-proof material such as SURLYN®, which is a trademark for an ionomer resin produced by DuPont. This combination of solid core and cover materials provides a golf ball that is virtually indestructible by golfers. Typical materials used in these two piece golf balls have a flexural modulus of greater than about 40,000 psi. In addition, this combination of solid core and cover produces a golf ball having a high initial velocity, which results in improved distance. Therefore, two piece golf balls are popular with recreational golfers because these balls provide high durability and maximum distance.
The stiffness and rigidity that provide the durability and improved distance, however, also produce a relatively low spin rate in these two piece golf balls. Low spin rates make golf balls difficult to control, especially on shorter shots such as approach shots to greens. Higher spin rates, although allowing a more skilled player to maximize control of the golf ball on the short approach shots, adversely affect driving distance for less skilled players. For example, slicing and hooking the ball are constant obstacles for the lower skill level players. Slicing and hooking result when an unintentional side spin is imparted on the ball as a result of not striking the ball squarely with the face of the golf club. In addition to limiting the distance that the golf ball will travel, unintentional side spin reduces a player's control over the ball. Lowering the spin rate of the golf ball reduces the adverse effects of unintentional side spin. Hence, recreational players typically prefer golf balls that exhibit low spin rate.
Various approaches have been taken to strike a balance between the spin rate and the playing characteristics of golf balls. For example, additional core layers, such as intermediate core and cover layers are added to the solid core golf balls in an attempt to improve the playing characteristics of the ball. These multi-layer solid core balls include multi-layer core constructions, multi-layer cover constructions and combinations thereof. In a golf ball with a multi-layer core, the principal source of resiliency is the multi-layer core. In a golf ball with a multi-layer cover and single-layer core, the principal source of resiliency is the single-layer core.
In addition, varying the materials, density or specific gravity among the multiple layers of the golf ball controls the spin rate. In general, the total weight of a golf ball has to conform to weight limits set by the United States Golf Association (“USGA”). Although the total weight of the golf ball is controlled, the distribution of weight within the ball can vary. Redistributing the weight or mass of the golf ball either toward the center of the ball or toward the outer surface of the ball changes the dynamic characteristics of the ball at impact and in flight. Specifically, if the density is shifted or redistributed toward the center of the ball, the moment of inertia of the golf ball is reduced, and the initial spin rate of the ball as it leaves the golf club increases as a result of the higher resistance from the golf ball's moment of inertia. Conversely, if the density is shifted or redistributed toward the outer surface of the ball, the moment of inertia is increased, and the initial spin rate of the ball as it leaves the golf club would decrease as a result of the higher resistance from the golf ball's moment of inertia.
The redistribution of weight within the golf ball is typically accomplished by adding fillers to one or more of the core or cover layers of the golf ball. Conventional fillers include the high specific gravity fillers, such as metal or metal alloy powders, metal oxide, metal stearates, particulates, and carbonaceous materials and low specific gravity fillers, such as hollow spheres, microspheres and foamed particles. However, the addition of fillers may adversely interfere with the resiliency of the polymers used in golf balls and thereby the coefficient of restitution of the golf balls.
Prior art golf balls have multiple core layers to provide desired playing characteristics. For example, U.S. Pat. No. 5,184,828 claims to provide a golf ball having two core layers configured to provide superior rebound characteristics and carry distance, while maintaining adequate spin rate. More particularly, the patent teaches an inner core and an outer layer and controlling the hardness distribution in the outer layer and in the inner core in such a way that the golf ball has a maximum hardness at the outer site of the inner core. The patent alleges that such a distribution of hardness in the core assembly allows high energy to accumulate at the interface region where the hardness is at a maximum. The patent further claims that the energy of the club face is efficiently delivered to the maximum hardness region and transferred toward the inner core, resulting in a high rebound coefficient. However, since golf balls having hard cores and soft covers provide the most spin, the distribution taught by this patent would result in maximum core hardness at the interface when hit by a driver. Therein the ball has a relatively high driver spin rate and not very good distance. Since the ball in this patent has a softer outer core layer, the ball should have a lower spin rate for shorter shots such as an eight iron, where spin is more desirable. Thus, the ball taught by this patent appears to have many disadvantages.
U.S. Pat. No. 6,786,838 of Sullivan et al. discloses golf balls having at least three core layers (and up to six core layers) wherein the thickness of each core layer is at least twice as thick as an adjacent outer core layer and each core layer having a different hardness. The core layers have either progressively increasing or decreasing hardness from the innermost core layer to the outermost core layer.
However, none of these references discloses a multi-layered core golf ball wherein each core layer has a plurality of hardnesses and a hardness gradient (positive, negative or a combination) within each respective core layer in addition to a hardness gradient as between core layers.
Co-pending related U.S. patent application Ser. Nos. 12/469,258, 12/469,312, 12/492,514 and 12/492,570, incorporated herein by reference, disclose and claim golf balls having single layer cores comprising different regions of varying hardness within the single layer core. The present invention extends this to the multi-layer core golf ball in order to reduce or eliminate the increased manufacturing costs and difficulty which often result when the properties of inner core layers are undesirably altered or deteriorated as outer core layers are cured or otherwise mounted or formed around the inner core layer by applying heat. The inventive plurality of hardnesses and hardness gradient within each layer of the multi-layered golf balls of the present invention therefore provide and optimize all of the benefits of a multi-layer core golf ball meanwhile reducing and minimizing the number of core layers heretofore necessary in order to achieve and optimize those benefits.
SUMMARY OF THE INVENTION
A multi-layered core golf ball wherein each core layer comprises its own hardness gradient (positive, negative or a combination) in addition to an overall hardness gradient from one core layer to the next. The inventive golf balls of the invention may also include at least a cover layer surrounding the multi-layer core.
In a first embodiment, the golf ball comprises a two layer core and a cover disposed about the two layer core. The two layer core comprises an inner core layer and an outer core layer disposed about the inner core layer. The inner core layer comprises a geometric center and a first outer surface. The inner core layer is formed from a substantially homogenous formulation, comprises a diameter of about 30 mm or lower, and has a plurality of hardnesses of from about 50 Shore C to about 90 Shore C. The geometric center comprises a first hardness and the first outer surface comprises a second hardness wherein the first hardness is greater than the second hardness to define a negative hardness gradient of about 20 Shore C or greater. The outer core layer comprises an inner surface and a second outer surface. The outer core layer is formed from a substantially homogenous formulation, comprises a thickness of about 10 mm or lower, and has a plurality of hardnesses of from about 50 Shore C to about 95 Shore C. The inner surface comprises a third hardness and the second outer surface comprises a fourth hardness wherein the fourth hardness is greater than the third hardness to define a positive hardness gradient of about 20 Shore C or greater. The outer core layer further comprises a fifth hardness disposed between the inner surface and the second outer surface in a region extending between about 10% and about 90% of the distance from the inner surface to the second outer surface, wherein the fifth hardness is greater than the first hardness, the third hardness and the fourth hardness. Finally, the fourth hardness is similar to or less than the first hardness.
As used herein, the phrase “plurality of hardnesses” includes the first, second, third, fourth and/or fifth hardnesses within the inner core and outer core layers as well as any additional hardnesses which may further define regions of varying hardness within each core layer as well as between core layers.
The first embodiment may alternatively include the following elements: The third hardness may be similar to the second hardness; the fifth hardness may be disposed between the inner surface and the second outer surface in a region extending radially from about 13 mm to about 20 mm from the geometric center; the diameter of the inner core layer may be about 26 mm or lower; the first hardness may be greater than the second hardness to define a negative hardness gradient of about 20 Shore C or greater; and the fourth hardness may be greater than the third hardness to define a positive hardness gradient of about 25 Shore C or greater.
In a second embodiment, the dual layer core differs from that of the first embodiment at least in that: the plurality of hardnesses of the outer core layer is from about 50 Shore C to about 80 Shore C; the fifth hardness is similar to or less than the first hardness and is greater than the third hardness; the fourth hardness is greater than the third hardness to define a positive hardness gradient of about 15 Shore C or lower or about 10 Shore C or lower; the fourth hardness is less than the first hardness.
In a third embodiment, the dual layer core differs from that of the first embodiment at least in that: the plurality of hardnesses of the outer core layer is from about 40 Shore C to about 75 Shore C; the fourth hardness is similar to or less than the third hardness; and the fifth hardness is less than the third hardness and the fourth hardness.
Alternatively, in the first embodiment, the plurality of hardnesses of the inner core layer and the outer core layer may range from about 55 Shore C to about 85 Shore C and from about 55 Shore C to about 90 Shore C, respectively. In the second embodiment, the plurality of hardnesses of the inner core layer and the outer core layer may each also range from about 55 Shore C to about 85 Shore C. In the third embodiment, the plurality of hardnesses of the inner core layer and the outer core layer may additionally range from about 55 Shore C to about 85 Shore C and from about 50 Shore C to about 85 Shore C, respectively.
In a fourth embodiment, the golf ball comprises a two layer core and a cover disposed about the two layer core. The two layer core comprises an inner core layer and an outer core layer disposed about the inner core layer. The inner core layer comprises a geometric center and a first outer surface. The inner core layer is formed from a substantially homogenous formulation, comprises a diameter of about 30 mm or lower, and has a plurality of hardnesses of from about 30 Shore D to about 68 Shore D. The geometric center comprises a first hardness and the first outer surface comprises a second hardness, wherein the first hardness is greater than the second hardness to define a negative hardness gradient of about 20 Shore D or greater. The outer core layer comprises an inner surface and a second outer surface. The outer core layer is formed from a substantially homogenous formulation, comprises a thickness of about 10 mm or lower, and has a plurality of hardnesses of from about 30 Shore D to about 68 Shore D. The inner surface comprises a third hardness and the second outer surface comprises a fourth hardness, wherein the fourth hardness is greater than the third hardness to define a positive hardness gradient of about 20 Shore D or greater. The outer core layer further comprises a fifth hardness disposed between the inner surface and the second outer surface in a region extending between about 10% and about 90% of the distance from the inner surface to the second outer surface, wherein the fifth hardness is greater than the first hardness, the third hardness and the fourth hardness. Finally, the fourth hardness is similar to or less than the first hardness.
The fourth embodiment may alternatively include the following elements: The third hardness may be similar to the second hardness; the fifth hardness may be disposed between the inner surface and the second outer surface in a region extending radially from about 13 mm to about 20 mm from the geometric center; the diameter of the inner core layer may be about 26 mm or lower; the first hardness may be greater than the second hardness to define a negative hardness gradient of about 25 Shore D or greater; and the fourth hardness may be greater than the third hardness to define a positive hardness gradient of about 25 Shore D or greater.
In a fifth embodiment, the dual layer core differs from that of the fourth embodiment at least in that: The outer core layer has a plurality of hardnesses of from about 30 Shore D to about 55 Shore D; the fourth hardness is greater than the third hardness to define a positive hardness gradient of about 10 Shore D or lower; the fifth hardness is similar to or less than the first hardness; and the fourth hardness is less than the first hardness.
In a sixth embodiment, the dual layer core differs from that of the fourth and fifth embodiments at least in that: the plurality of hardnesses of the outer core layer is from about 25 Shore D to about 45 Shore D; the fourth hardness is similar to or less than the third hardness; and the fifth hardness is less than the third hardness and the fourth hardness.
Alternatively, in the fourth embodiment, the plurality of hardnesses of the inner core layer and the outer core layer may range from about 25 Shore D to about 56 Shore D and from about 25 Shore D to about 60 Shore D, respectively. In the fifth embodiment, the plurality of hardnesses of the inner core layer and the outer core layer may each also range from about 25 Shore D to about 56 Shore D. In the sixth embodiment, the plurality of hardnesses of the inner core layer and the outer core layer may range from about 25 Shore D to about 56 Shore D and from about 20 Shore D to about 56 Shore D, respectively.
In embodiments one through six, the inner core layer may comprise antioxidant in an amount of from about 0.2 phr to about 1.2 phr. Additionally, the inner core layer may comprise peroxide in an amount of from about 0.5 phr to about 1.2 phr. The resulting ratio of antioxidant to initiator of the inner core layer may be from about 0.33 to about 4.8.
In embodiments one and four, the outer core layer may not comprise any antioxidant. However, it is envisioned that the formulation for embodiments one and four may be modified so that the outer core layer does indeed comprise antioxidant.
In embodiments two and five, the outer core layer may comprise antioxidant in an amount of about 1.0 phr or less.
In embodiments three and six, the outer core layer may comprise antioxidant in an amount of from about 0.2 phr to about 1.2 phr.
The inner and outer core may comprise peroxide as disclosed in Table I herein, including either a single peroxide or a combination of peroxides.
In embodiments one and six, the ratio of antioxidant to initiator of the outer core layer is zero where the outer core layer does not comprise any antioxidant. In embodiments two and five, the ratio of antioxidant to initiator of the outer core layer may be about 10.0 or less. In embodiments three and six, the ratio of antioxidant to initiator of the outer core layer may be from about 0.33 to about 4.8.
In each of embodiments one through six, the inner core layer may comprise polybutadiene in an amount of about 100 phr and the outer core layer may comprise polybutadiene in an amount of from about 85 phr to about 100 phr. Furthermore, the inner core layer may comprise zinc diacrylate in an amount of from about 40 phr to about 50 phr and the outer core layer may comprise zinc diacrylate in an amount of from about 30 phr to about 45 phr. Additionally, the inner core layer and the outer core layer may each comprise zinc oxide in an amount of from about 5 phr to about 10 phr. Moreover, the inner core layer and the outer core layer may each comprise zinc pentachlorothiophenol in an amount of about 3 phr or less. Further, the inner core layer and the outer core layer may each comprise regrind in an amount of from about 10 phr to about 30 phr. In addition, the inner core layer and the outer core layer may each comprise trans polyisoprene in an amount of about 15 phr or less. Barium sulfate may be included in each core layer in an amount sufficient to target a desired specific gravity.
In an alternative embodiment, the inner core layer and the outer core layer each comprises peroxide in an amount of from about 0.2 phr to about 3.0 phr and antioxidant in an amount of about 2.5 phr or less.
It is preferred that the golf ball of the present invention comprise two core layers and a cover in order to maximize the benefits achieved from such a golf ball construction—namely reducing or eliminating the increased manufacturing costs and difficulty which often result when the properties of inner core layers are undesirably altered or deteriorated as outer core layers are cured or otherwise mounted or formed around the inner core layer by applying heat. However, it is recognized and envisioned that the inventive golf ball may comprise and extend to any number of core layers, intermediate layers, and/or cover layers having regions of varying hardness within and between each layer.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings which forms a part of the specification and is to be read in conjunction therewith:
FIG. 1 is a cross-sectional view of a golf ball formed according to one embodiment of the present invention.
FIG. 2 is a graph of the Shore C hardness of an inventive multi-layer core as a function of the distance from its center according to illustrative embodiments; and
FIG. 3 is a graph of the Shore D hardness of an inventive multi-layer core as a function of the distance from its center according to illustrative embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As briefly discussed above, each inventive core layer may have a hardness gradient defined by hardness measurements made at the surface of the inner core (or outer core layer) and radially inward toward the center of the inner core, typically at 2-mm increments. As used herein, the terms “negative” and “positive” refer to the result of subtracting the hardness value at the innermost portion of the component being measured from the hardness value at the outer surface of the component being measured. For example, if the outer surface of a core layer has a greater hardness value than its innermost surface, the hardness gradient will be deemed a “positive” gradient. Alternatively, if the inner surface of one layer of a multi-layer core has a greater hardness value than its inner surface, the hardness gradient for that core layer will be deemed a “negative” gradient.
Each region of a core layer (inner core region, or outer core region or intermediate core region) may be made from a composition including at least one thermoset base rubber, such as a polybutadiene rubber, cured with at least one peroxide and at least one reactive co-agent, which can be a metal salt of an unsaturated carboxylic acid, such as acrylic acid or methacrylic acid, a non-metallic coagent, or mixtures thereof. Preferably, a suitable antioxidant is included in the composition. An optional soft and fast agent (and sometimes a cis-to-trans catalyst), such as an organosulfur or metal-containing organosulfur compound, can also be included in the core formulation.
Other ingredients that are known to those skilled in the art may be used, and are understood to include, but not be limited to, density-adjusting fillers, process aides, plasticizers, blowing or foaming agents, sulfur accelerators, and/or non-peroxide radical sources.
The base thermoset rubber, which can be blended with other rubbers and polymers, typically includes a natural or synthetic rubber. A preferred base rubber is 1,4-polybutadiene having a cis structure of at least 40%, preferably greater than 80%, and more preferably greater than 90%.
Examples of desirable polybutadiene rubbers include BUNA® CB22 and BUNA® CB23, TAKTENE® 1203G1, 220, 221, and PETROFLEX® BRNd-40, commercially available from LANXESS Corporation; BR-1220 available from BST Elastomers Co. LTD; UBEPOL® 360L and UBEPOL® 150L and UBEPOL-BR rubbers, commercially available from UBE Industries, Ltd. of Tokyo, Japan; KINEX® 7245 and KINEX® 7265, commercially available from Goodyear of Akron, Ohio; SE BR-1220, commercially available from Dow Chemical Company; Europrene® NEOCIS® BR 40 and BR 60, commercially available from Polimeri Europa; and BR 01, BR 730, BR 735, BR 11, and BR 51, commercially available from Japan Synthetic Rubber Co., Ltd; and KARBOCHEM® ND40, ND45, and ND60, commercially available from Karbochem.
The base rubber may also comprise high or medium Mooney viscosity rubber, or blends thereof. The measurement of Mooney viscosity is defined according to ASTM D-1646.
The Mooney viscosity range is preferably greater than about 30, more preferably in the range from about 35 to about 75 and more preferably in the range from about 40 to about 60. Polybutadiene rubber with higher Mooney viscosity may also be used, so long as the viscosity of the polybutadiene does not reach a level where the high viscosity polybutadiene clogs or otherwise adversely interferes with the manufacturing machinery. It is contemplated that polybutadiene with viscosity less than about 75 Mooney can be used with the present invention.
In one embodiment of the present invention, golf ball cores made with mid- to high-Mooney viscosity polybutadiene material exhibit increased resiliency (and, therefore, distance) without increasing the hardness of the ball.
Commercial sources of suitable mid- to high-Mooney viscosity polybutadiene include Lanxess Buna CB23 (Nd-catalyzed), which has a Mooney viscosity of around 50 and is a highly linear polybutadiene, and Dow SE BR-1220 (Co-catalyzed). If desired, the polybutadiene can also be mixed with other elastomers known in the art, such as other polybutadiene rubbers, natural rubber, styrene butadiene rubber, and/or isoprene rubber in order to further modify the properties of the core. When a mixture of elastomers is used, the amounts of other constituents in the core composition are typically based on 100 parts by weight of the total elastomer mixture.
In one preferred embodiment, the base rubber comprises a transition metal polybutadiene, a rare earth-catalyzed polybutadiene rubber, or blends thereof. If desired, the polybutadiene can also be mixed with other elastomers known in the art such as natural rubber, polyisoprene rubber and/or styrene-butadiene rubber in order to modify the properties of the core. Other suitable base rubbers include thermosetting materials such as, ethylene propylene diene monomer rubber, ethylene propylene rubber, butyl rubber, halobutyl rubber, hydrogenated nitrile butadiene rubber, nitrile rubber, and silicone rubber.
Thermoplastic elastomers (TPE) many also be used to modify the properties of the core layers, or the uncured core layer stock by blending with the base thermoset rubber. These TPEs include natural or synthetic balata, or high trans-polyisoprene, high trans-polybutadiene, or any styrenic block copolymer, such as styrene ethylene butadiene styrene, styrene-isoprene-styrene, etc., a metallocene or other single-site catalyzed polyolefin such as ethylene-octene, or ethylene-butene, or thermoplastic polyurethanes (TPU), including copolymers, e.g. with silicone. Other suitable TPEs for blending with the thermoset rubbers of the present invention include PEBAX®, which is believed to comprise polyether amide copolymers, HYTREL®, which is believed to comprise polyether ester copolymers, thermoplastic urethane, and KRATON®, which is believed to comprise styrenic block copolymers elastomers. Any of the TPEs or TPUs above may also contain functionality suitable for grafting, including maleic acid or maleic anhydride.
Additional polymers may also optionally be incorporated into the base rubber. Examples include, but are not limited to, thermoset elastomers such as core regrind, thermoplastic vulcanizate, copolymeric ionomer, terpolymeric ionomer, polycarbonate, polyamides, copolymeric polyamides, polyesters, polyvinyl alcohols, acrylonitrile-butadiene-styrene copolymers, polyarylate, polyacrylate, polyphenylene ether, impact-modified polyphenylene ether, high impact polystyrene, diallyl phthalate polymer, styrene-acrylonitrile polymer (SAN) (including olefin-modified SAN and acrylonitrile-styrene-acrylonitrile polymer), styrene-maleic anhydride copolymer, styrenic copolymer, functionalized styrenic copolymer, functionalized styrenic terpolymer, styrenic terpolymer, cellulose polymer, liquid crystal polymer, ethylene-vinyl acetate copolymers, polyurea, and polysiloxane or any metallocene-catalyzed polymers of these species.
Suitable polyamides for use as an additional polymeric material in compositions within the scope of the present invention also include resins obtained by: (1) polycondensation of (a) a dicarboxylic acid, such as oxalic acid, adipic acid, sebacic acid, terephthalic acid, isophthalic acid, or 1,4-cyclohexanedicarboxylic acid, with (b) a diamine, such as ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, or decamethylenediamine, 1,4-cyclohexanediamine, or m-xylylenediamine; (2) a ring-opening polymerization of cyclic lactam, such as -caprolactam or Ω-laurolactam; (3) polycondensation of an aminocarboxylic acid, such as 6-aminocaproic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, or 12-aminododecanoic acid; or (4) copolymerization of a cyclic lactam with a dicarboxylic acid and a diamine. Specific examples of suitable polyamides include NYLON 6, NYLON 66, NYLON 610, NYLON 11, NYLON 12, copolymerized NYLON, NYLON MXD6, and NYLON 46.
Suitable peroxide initiating agents include dicumyl peroxide; 2,5-dimethyl-2,5-di(t-butylperoxy)hexane; 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne; 2,5-dimethyl-2,5-di(benzoylperoxy)hexane; 2,2′-bis(t-butylperoxy)-di-iso-propylbenzene; 1,1-bis(t-butylperoxy)-3,3,5-trimethyl cyclohexane; n-butyl 4,4-bis(t-butyl-peroxy)valerate; t-butyl perbenzoate; benzoyl peroxide; n-butyl 4,4′-bis(butylperoxy) valerate; di-t-butyl peroxide; or 2,5-di-(t-butylperoxy)-2,5-dimethyl hexane, lauryl peroxide, t-butyl hydroperoxide, α-α bis(t-butylperoxy) diisopropylbenzene, di(2-t-butyl-peroxyisopropyl)benzene, di-t-amyl peroxide, di-t-butyl peroxide. Commercially-available peroxide initiating agents include DICUPT™ family of dicumyl peroxides (including DICUP™ R, DICUP™ 40C and DICUP™ 40KE) available from Crompton (Geo Specialty Chemicals). Similar initiating agents are available from AkroChem, Lanxess, Flexsys/Harwick and R.T. Vanderbilt. Another commercially-available and preferred initiating agent is TRIGONOXT™ 265-50B from Akzo Nobel, which is a mixture of 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane and di(2-t-butylperoxyisopropyl) benzene. TRIGONOX™ peroxides are generally sold on a carrier compound. Additionally or alternatively, VAROX ANS may be used. Herein, the terms “peroxide initiating agents”, peroxide(s), initiating agent(s) and initiator(s) are used interchangeably.
Suitable reactive co-agents include, but are not limited to, metal salts of diacrylates, dimethacrylates, and monomethacrylates suitable for use in this invention include those wherein the metal is zinc, magnesium, calcium, barium, tin, aluminum, lithium, sodium, potassium, iron, zirconium, and bismuth. Zinc diacrylate (ZDA) is preferred, but the present invention is not limited thereto. ZDA provides golf balls with a high initial velocity. The ZDA can be of various grades of purity. For the purposes of this invention, the lower the quantity of zinc stearate present in the ZDA the higher the ZDA purity. ZDA containing less than about 20% zinc stearate is preferable. More preferable is ZDA containing about 4-8% zinc stearate. Suitable, commercially available zinc diacrylates include those from Sartomer Co. The ZDA amount can be varied to suit the desired compression, spin and feel of the resulting golf ball.
Additional preferred co-agents that may be used alone or in combination with those mentioned above include, but are not limited to, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, and the like. It is understood by those skilled in the art, that in the case where these co-agents may be liquids at room temperature, it may be advantageous to disperse these compounds on a suitable carrier to promote ease of incorporation in the rubber mixture.
Antioxidants are compounds that inhibit or prevent the oxidative breakdown of elastomers, and/or inhibit or prevent reactions that are promoted by oxygen radicals. Some exemplary antioxidants that may be used in the present invention include, but are not limited to, quinoline type antioxidants, amine type antioxidants, and phenolic type antioxidants. A preferred antioxidant is 2,2′-methylene-bis-(4-methyl-6-t-butylphenol) available as VANOX® MBPC from R.T. Vanderbilt. Other polyphenolic antioxidants include VANOX® T, VANOX® L, VANOX® SKT, VANOX® SWP, VANOX® 13 and VANOX® 1290.
Suitable antioxidants include, but are not limited to, alkylene-bis-alkyl substituted cresols, such as 4,4′-methylene-bis(2,5-xylenol); 4,4′-ethylidene-bis-(6-ethyl-m-cresol); 4,4′-butylidene-bis-(6-t-butyl-m-cresol); 4,4′-decylidene-bis-(6-methyl-m-cresol); 4,4′-methylene-bis-(2-amyl-m-cresol); 4,4′-propylidene-bis-(5-hexyl-m-cresol); 3,3′-decylidene-bis-(5-ethyl-p-cresol); 2,2′-butylidene-bis-(3-n-hexyl-p-cresol); 4,4′-(2-butylidene)-bis-(6-t-butyl-m-cresol); 3,3′-4(decylidene)-bis-(5-ethyl-p-cresol); (2,5-dimethyl-4-hydroxyphenyl) (2-hydroxy-3,5-dimethylphenyl) methane; (2-methyl-4-hydroxy-5-ethylphenyl) (2-ethyl-3-hydroxy-5-methylphenyl) methane; (3-methyl-5-hydroxy-6-t-butylphenyl) (2-hydroxy-4-methyl-5-decylphenyl)-n-butyl methane; (2-hydroxy-4-ethyl-5-methylphenyl) (2-decyl-3-hydroxy-4-methylphenyl)butylamylmethane; (3-ethyl-4-methyl-5-hydroxyphenyl)-(2,3-dimethyl-3-hydroxy-phenyl)nonylmethane; (3-methyl-2-hydroxy-6-ethylphenyl)-(2-isopropyl-3-hydroxy-5-methyl-phenyl)cyclohexylmethane; (2-methyl-4-hydroxy-5-methylphenyl)-(2-hydroxy-3-methyl-5-ethylphenyl)dicyclohexyl methane; and the like.
Other suitable antioxidants include, but are not limited to, substituted phenols, such as 2-tert-butyl-4-methoxyphenol; 3-tert-butyl-4-methoxyphenol; 3-tert-octyl-4-methoxyphenol; 2-methyl-4-methoxyphenol; 2-stearyl-4-n-butoxyphenol; 3-t-butyl-4-stearyloxyphenol; 3-lauryl-4-ethoxyphenol; 2,5-di-t-butyl-4-methoxyphenol; 2-methyl-4-methoxyphenol; 2-(1-methycyclohexyl)-4-methoxyphenol;2-t-butyl-4-dodecyloxyphenol; 2-(1-methylbenzyl)-4-methoxyphenol; 2-t-octyl-4-methoxyphenol; methyl gallate; n-propyl gallate; n-butyl gallate; lauryl gallate; myristyl gallate; stearyl gallate; 2,4,5-trihydroxyacetophenone; 2,4,5-trihydroxy-n-butyrophenone; 2,4,5-trihydroxystearophenone; 2,6-ditert-butyl-4-methylphenol; 2,6-ditert-octyl-4-methylphenol; 2,6-ditert-butyl-4-stearylphenol; 2-methyl-4-methyl-6-tert-butylphenol; 2,6-distearyl-4-methylphenol; 2,6-dilauryl-4-methylphenol; 2,6-di(n-octyl)-4-methylphenol; 2,6-di(n-hexadecyl)-4-methylphenol; 2,6-di(1-methylundecyl)-4-methylphenol; 2,6-di(1-methylheptadecyl)-4-methylphenol; 2,6-di(trimethylhexyl)-4-methylphenol; 2,6-di(1,1,3,3-tetramethyloctyl)-4-methylphenol; 2-n-dodecyl-6-tert butyl-4-methylphenol; 2-n-dodecyl-6-(1-methylundecyl)-4-methylphenol; 2-n-dodecyl-6-(1,1,3,3-tetramethyloctyl)-4-methylphenol; 2-n-dodecyl-6-n-octadecyl-4-methylphenol; 2-n-dodecyl-6-n-octyl-4-methylphenol; 2-methyl-6-n-octadecyl-4-methylphenol; 2-n-dodecyl-6-(1-methylheptadecyl)-4-methylphenol; 2,6-di(1-methylbenzyl)-4-methylphenol; 2,6-di(1-methylcyclohexyl)-4-methylphenol; 2,6-(1-methylcyclohexyl)-4-methylphenol; 2-(1-methylbenzyl)-4-methylphenol; and related substituted phenols.
More suitable antioxidants include, but are not limited to, alkylene bisphenols, such as 4,4′-butylidene bis(3-methyl-6-t-butyl phenol); 2,2-butylidene bis(4,6-dimethyl phenol); 2,2′-butylidene bis(4-methyl-6-t-butyl phenol); 2,2′-butylidene bis(4-t-butyl-6-methyl phenol); 2,2′-ethylidene bis(4-methyl-6-t-butylphenol); 2,2′-methylene bis(4,6-dimethyl phenol); 2,2′-methylene bis(4-methyl-6-t-butyl phenol); 2,2′-methylene bis(4-ethyl-6-t-butyl phenol); 4,4′-methylene bis(2,6-di-t-butyl phenol); 4,4′-methylene bis(2-methyl-6-t-butyl phenol); 4,4′-methylene bis(2,6-dimethyl phenol); 2,2′-methylene bis(4-t-butyl-6-phenyl phenol); 2,2′-dihydroxy-3,3′,5,5′-tetramethylstilbene; 2,2′-isopropylidene bis(4-methyl-6-t-butyl phenol); ethylene bis(beta-naphthol); 1,5-dihydroxy naphthalene; 2,2′-ethylene bis(4-methyl-6-propyl phenol); 4,4′-methylene bis(2-propyl-6-t-butyl phenol); 4,4′-ethylene bis(2-methyl-6-propyl phenol); 2,2′-methylene bis(5-methyl-6-t-butyl phenol); and 4,4′-butylidene bis(6-t-butyl-3-methyl phenol).
Suitable antioxidants further include, but are not limited to, alkylene trisphenols, such as 2,6-bis(2′-hydroxy-3′-t-butyl-5′-methyl benzyl)-4-methyl phenol; 2,6-bis(2′-hydroxy-3′-t-ethyl-5′-butyl benzyl)-4-methyl phenol; and 2,6-bis(2′-hydroxy-3′-t-butyl-5′-propyl benzyl)-4-methyl phenol.
The thermoset rubber composition of the present invention may also include an optional soft and fast agent. As used herein, “soft and fast agent” means any compound or a blend thereof that that is capable of making a core 1) be softer (lower compression) at constant COR or 2) have a higher COR at equal compression, or any combination thereof, when compared to a core equivalently prepared without a soft and fast agent.
Suitable soft and fast agents include, but are not limited to, organosulfur or metal-containing organosulfur compounds, an organic sulfur compound, including mono, di, and polysulfides, a thiol, or mercapto compound, an inorganic sulfide compound, a Group VIA compound, or mixtures thereof. The soft and fast agent component may also be a blend of an organosulfur compound and an inorganic sulfide compound.
Suitable soft and fast agents of the present invention include, but are not limited to those having the following general formula:
where R 1 -R 5 can be C 1 -C 8 alkyl groups; halogen groups; thiol groups (—SH), carboxylated groups; sulfonated groups; and hydrogen; in any order; and also pentafluorothiophenol; 2-fluorothiophenol; 3-fluorothiophenol; 4-fluorothiophenol; 2,3-fluorothiophenol; 2,4-fluorothiophenol; 3,4-fluorothiophenol; 3,5-fluorothiophenol 2,3,4-fluorothiophenol; 3,4,5-fluorothiophenol; 2,3,4,5-tetrafluorothiophenol; 2,3,5,6-tetrafluorothiophenol; 4-chlorotetrafluorothiophenol; pentachlorothiophenol; 2-chlorothiophenol; 3-chlorothiophenol; 4-chlorothiophenol; 2,3-chlorothiophenol; 2,4-chlorothiophenol; 3,4-chlorothiophenol; 3,5-chlorothiophenol; 2,3,4-chlorothiophenol; 3,4,5-chlorothiophenol; 2,3,4,5-tetrachlorothiophenol; 2,3,5,6-tetrachlorothiophenol; pentabromothiophenol; 2-bromothiophenol; 3-bromothiophenol; 4-bromothiophenol; 2,3-bromothiophenol; 2,4-bromothiophenol; 3,4-bromothiophenol; 3,5-bromothiophenol; 2,3,4-bromothiophenol; 3,4,5-bromothiophenol; 2,3,4,5-tetrabromothiophenol; 2,3,5,6-tetrabromothiophenol; pentaiodothiophenol; 2-iodothiophenol; 3-iodothiophenol; 4-iodothiophenol; 2,3-iodothiophenol; 2,4-iodothiophenol; 3,4-iodothiophenol; 3,5-iodothiophenol; 2,3,4-iodothiophenol; 3,4,5-iodothiophenol; 2,3,4,5-tetraiodothiophenol; 2,3,5,6-tetraiodothiophenoland; and their zinc salts. Preferably, the halogenated thiophenol compound is pentachlorothiophenol, which is commercially available in neat faun or under the tradename STRUKTOL®, a clay-based carrier containing the sulfur compound pentachlorothiophenol loaded at 45 percent (correlating to 2.4 parts PCTP). STRUKTOL® is commercially available from Struktol Company of America of Stow, Ohio. PCTP is commercially available in neat form from eChinachem of San Francisco, Calif. and in the salt form from eChinachem of San Francisco, Calif. Most preferably, the halogenated thiophenol compound is the zinc salt of pentachlorothiophenol, which is commercially available from eChinachem of San Francisco, Calif.
As used herein when referring to the invention, the term “organosulfur compound(s)” refers to any compound containing carbon, hydrogen, and sulfur, where the sulfur is directly bonded to at least 1 carbon. As used herein, the term “sulfur compound” means a compound that is elemental sulfur, polymeric sulfur, or a combination thereof. It should be further understood that the term “elemental sulfur” refers to the ring structure of S 8 and that “polymeric sulfur” is a structure including at least one additional sulfur relative to elemental sulfur.
Additional suitable examples of soft and fast agents (that are also believed to be cis-to-trans catalysts) include, but are not limited to, 4,4′-diphenyl disulfide; 4,4′-ditolyl disulfide; 2,2′-benzamido diphenyl disulfide; bis(2-aminophenyl) disulfide; bis(4-aminophenyl) disulfide; bis(3-aminophenyl) disulfide; 2,2′-bis(4-aminonaphthyl) disulfide; 2,2′-bis(3-aminonaphthyl) disulfide; 2,2′-bis(4-aminonaphthyl) disulfide; 2,2′-bis(5-aminonaphthyl) disulfide; 2,2′-bis(6-aminonaphthyl) disulfide; 2,2′-bis(7-aminonaphthyl) disulfide; 2,2′-bis(8-aminonaphthyl) disulfide; 1,1′-bis(2-aminonaphthyl) disulfide; 1,1′-bis(3-aminonaphthyl) disulfide; 1,1′-bis(3-aminonaphthyl) disulfide; 1,1′-bis(4-aminonaphthyl) disulfide; 1,1′-bis(5-aminonaphthyl) disulfide; 1,1′-bis(6-aminonaphthyl) disulfide; 1,1′-bis(7-aminonaphthyl) disulfide; 1,1′-bis(8-aminonaphthyl) disulfide; 1,2′-diamino-1,2′-dithiodinaphthalene; 2,3′-diamino-1,2′-dithiodinaphthalene; bis(4-chlorophenyl) disulfide; bis(2-chlorophenyl) disulfide; bis(3-chlorophenyl) disulfide; bis(4-bromophenyl) disulfide; bis(2-bromophenyl) disulfide; bis(3-bromophenyl) disulfide; bis(4-fluorophenyl) disulfide; bis(4-iodophenyl) disulfide; bis(2,5-dichlorophenyl) disulfide; bis(3,5-dichlorophenyl) disulfide; bis(2,4-dichlorophenyl) disulfide; bis(2,6-dichlorophenyl) disulfide; bis(2,5-dibromophenyl) disulfide; bis(3,5-dibromophenyl) disulfide; bis(2-chloro-5-bromophenyl) disulfide; bis(2,4,6-trichlorophenyl) disulfide; bis(2,3,4,5,6-pentachlorophenyl) disulfide; bis(4-cyanophenyl) disulfide; bis(2-cyanophenyl) disulfide; bis(4-nitrophenyl) disulfide; bis(2-nitrophenyl) disulfide; 2,2′-dithiobenzoic acid ethylester; 2,2′-dithiobenzoic acid methylester; 2,2′-dithiobenzoic acid; 4,4′-dithiobenzoic acid ethylester; bis(4-acetylphenyl) disulfide; bis(2-acetylphenyl) disulfide; bis(4-formylphenyl) disulfide; bis(4-carbamoylphenyl) disulfide; 1,1′-dinaphthyl disulfide; 2,2′-dinaphthyl disulfide; 1,2′-dinaphthyl disulfide; 2,2′-bis(1-chlorodinaphthyl) disulfide; 2,2′-bis(1-bromonaphthyl) disulfide; 1,1′-bis(2-chloronaphthyl) disulfide; 2,2′-bis(1-cyanonaphthyl) disulfide; 2,2′-bis(1-acetylnaphthyl) disulfide; and the like; or a mixture thereof. Preferred organosulfur components include 4,4′-diphenyl disulfide, 4,4′-ditolyl disulfide, or 2,2′-benzamido diphenyl disulfide, or a mixture thereof. A more preferred organosulfur component includes 4,4′-ditolyl disulfide. In another embodiment, metal-containing organosulfur components can be used according to the invention. Suitable metal-containing organosulfur components include, but are not limited to, cadmium, copper, lead, and tellurium analogs of diethyldithiocarbamate, diamyldithiocarbamate, and dimethyldithiocarbamate, or mixtures thereof.
Suitable substituted or unsubstituted aromatic organic components that do not include sulfur or a metal include, but are not limited to, 4,4′-diphenyl acetylene, azobenzene, or a mixture thereof. The aromatic organic group preferably ranges in size from C 6 to C 20 , and more preferably from C 6 to C 10 . Suitable inorganic sulfide components include, but are not limited to titanium sulfide, manganese sulfide, and sulfide analogs of iron, calcium, cobalt, molybdenum, tungsten, copper, selenium, yttrium, zinc, tin, and bismuth.
A substituted or unsubstituted aromatic organic compound is also suitable as a soft and fast agent. Suitable substituted or unsubstituted aromatic organic components include, but are not limited to, components having the formula (R 1 ) x —R 3 -M-R 4 —(R 2 ) y , wherein R 1 and R 2 are each hydrogen or a substituted or unsubstituted C 1-20 linear, branched, or cyclic alkyl, alkoxy, or alkylthio group, or a single, multiple, or fused ring C 6 to C 24 aromatic group; x and y are each an integer from 0 to 5; R 3 and R 4 are each selected from a single, multiple, or fused ring C 6 to C 24 aromatic group; and M includes an azo group or a metal component. R 3 and R 4 are each preferably selected from a C 6 to C 10 aromatic group, more preferably selected from phenyl, benzyl, naphthyl, benzamido, and benzothiazyl. R 1 and R 2 are each preferably selected from a substituted or unsubstituted C 1-10 linear, branched, or cyclic alkyl, alkoxy, or alkylthio group or a C 6 to C 10 aromatic group. When R 1 , R 2 , R 3 , or R 4 , are substituted, the substitution may include one or more of the following substituent groups: hydroxy and metal salts thereof; mercapto and metal salts thereof halogen; amino, nitro, cyano, and amido; carboxyl including esters, acids, and metal salts thereof silyl; acrylates and metal salts thereof sulfonyl or sulfonamide; and phosphates and phosphites. When M is a metal component, it may be any suitable elemental metal available to those of ordinary skill in the art. Typically, the metal will be a transition metal, although preferably it is tellurium or selenium. In one embodiment, the aromatic organic compound is substantially free of metal, while in another embodiment the aromatic organic compound is completely free of metal.
The soft and fast agent can also include a Group VIA component. Elemental sulfur and polymeric sulfur are commercially available from Elastochem, Inc. of Chardon, Ohio. Exemplary sulfur catalyst compounds include PB(RM-S)-80 elemental sulfur and PB(CRST)-65 polymeric sulfur, each of which is available from Elastochem, Inc. An exemplary tellurium catalyst under the tradename TELLOY® and an exemplary selenium catalyst under the tradename VANDEX® are each commercially available from RT Vanderbilt.
Other suitable soft and fast agents include, but are not limited to, hydroquinones, benzoquinones, quinhydrones, catechols, and resorcinols.
Suitable hydroquinone compounds include compounds represented by the following formula, and hydrates thereof:
wherein each R 1 , R 2 , R 3 , and R 4 are hydrogen; halogen; alkyl; carboxyl; metal salts thereof, and esters thereof, acetate and esters thereof; formyl; acyl; acetyl; halogenated carbonyl; sulfo and esters thereof; halogenated sulfonyl; sulfino; alkylsulfinyl; carbamoyl; halogenated alkyl; cyano; alkoxy; hydroxy and metal salts thereof; amino; nitro; aryl; aryloxy; arylalkyl; nitroso; acetamido; or vinyl.
Other suitable hydroquinone compounds include, but are not limited to, hydroquionone; tetrachlorohydroquinone; 2-chlorohydroquionone; 2-bromohydroquinone; 2,5-dichlorohydroquinone; 2,5-dibromohydroquinone; tetrabromohydroquinone; 2-methylhydroquinone; 2-t-butylhydroquinone; 2,5-di-t-amylhydroquinone; and 2-(2-chlorophenyl)hydroquinone hydrate.
More suitable hydroquinone compounds include compounds represented by the following formula, and hydrates thereof:
wherein each R 1 , R 2 , R 3 , and R 4 are a metal salt of a carboxyl; acetate and esters thereof; hydroxy; a metal salt of a hydroxy; amino; nitro; aryl; aryloxy; arylalkyl; nitroso; acetamido; or vinyl.
Suitable benzoquinone compounds include compounds represented by the following formula, and hydrates thereof:
wherein each R 1 , R 2 , R 3 , and R 4 are hydrogen; halogen; alkyl; carboxyl; metal salts thereof, and esters thereof; acetate and esters thereof; formyl; acyl; acetyl; halogenated carbonyl; sulfo and esters thereof; halogenated sulfonyl; sulfino; alkylsulfinyl; carbamoyl; halogenated alkyl; cyano; alkoxy; hydroxy and metal salts thereof; amino; nitro; aryl; aryloxy; arylalkyl; nitroso; acetamido; or vinyl.
Other suitable benzoquinone compounds include one or more compounds represented by the following formula, and hydrates thereof:
wherein each R 1 , R 2 , R 3 , and R 4 are a metal salt of a carboxyl; acetate and esters thereof; hydroxy; a metal salt of a hydroxy; amino; nitro; aryl; aryloxy; arylalkyl; nitroso; acetamido; or vinyl.
Suitable quinhydrones include one or more compounds represented by the following formula, and hydrates thereof:
wherein each R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 are hydrogen; halogen; alkyl; carboxyl; metal salts thereof, and esters thereof; acetate and esters thereof; formyl; acyl; acetyl; halogenated carbonyl; sulfo and esters thereof; halogenated sulfonyl; sulfino; alkylsulfinyl; carbamoyl; halogenated alkyl; cyano; alkoxy; hydroxy and metal salts thereof; amino; nitro; aryl; aryloxy; arylalkyl; nitroso; acetamido; or vinyl.
Other suitable quinhydrones include those having the above formula, wherein each R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 are a metal salt of a carboxyl; acetate and esters thereof; hydroxy; a metal salt of a hydroxy; amino; nitro; aryl; aryloxy; arylalkyl; nitroso; acetamido; or vinyl.
Suitable catechols include one or more compounds represented by the following formula, and hydrates thereof:
wherein each R 1 , R 2 , R 3 , and R 4 are hydrogen; halogen; alkyl; carboxyl; metal salts thereof, and esters thereof; acetate and esters thereof; formyl; acyl; acetyl; halogenated carbonyl; sulfo and esters thereof; halogenated sulfonyl; sulfino; alkylsulfinyl; carbamoyl; halogenated alkyl; cyano; alkoxy; hydroxy and metal salts thereof; amino; nitro; aryl; aryloxy; arylalkyl; nitroso; acetamido; or vinyl.
Suitable resorcinols include one or more compounds represented by the following formula, and hydrates thereof:
wherein each R 1 , R 2 , R 3 , and R 4 are hydrogen; halogen; alkyl; carboxyl; metal salts thereof, and esters thereof; acetate and esters thereof; formyl; acyl; acetyl; halogenated carbonyl; sulfo and esters thereof; halogenated sulfonyl; sulfino; alkylsulfinyl; carbamoyl; halogenated alkyl; cyano; alkoxy; hydroxy and metal salts thereof; amino; nitro; aryl; aryloxy; arylalkyl; nitroso; acetamido; or vinyl.
Fillers may also be added to the thermoset rubber composition of the core to adjust the density of the composition, up or down. Typically, fillers include materials such as tungsten, zinc oxide, barium sulfate, silica, calcium carbonate, zinc carbonate, metals, metal oxides and salts, regrind (recycled core material typically ground to about 30 mesh particle), high-Mooney-viscosity rubber regrind, trans-regrind core material (recycled core material containing high trans-isomer of polybutadiene), and the like. When trans-regrind is present, the amount of trans-isomer is preferably between about 10% and about 60%. In a preferred embodiment of the invention, the core comprises polybutadiene having a cis-isomer content of greater than about 95% and trans-regrind core material (already vulcanized) as a filler. Any particle size trans-regrind core material is sufficient, but is preferably less than about 125 μm.
Fillers added to one or more portions of the golf ball typically include processing aids or compounds to affect rheological and mixing properties, density-modifying fillers, tear strength, or reinforcement fillers, and the like. The fillers are generally inorganic, and suitable fillers include numerous metals or metal oxides, such as zinc oxide and tin oxide, as well as barium sulfate, zinc sulfate, calcium carbonate, barium carbonate, clay, tungsten, tungsten carbide, an array of silicas, and mixtures thereof. Fillers may also include various foaming agents or blowing agents which may be readily selected by one of ordinary skill in the art. Fillers may include polymeric, ceramic, metal, and glass microspheres may be solid or hollow, and filled or unfilled. Fillers are typically also added to one or more portions of the golf ball to modify the density thereof to conform to uniform golf ball standards. Fillers may also be used to modify the weight of the center or at least one additional layer for specialty balls, e.g., a lower weight ball is preferred for a player having a low swing speed.
Materials such as tungsten, zinc oxide, barium sulfate, silica, calcium carbonate, zinc carbonate, metals, metal oxides and salts, and regrind (recycled core material typically ground to about 30 mesh particle) are also suitable fillers.
The polybutadiene and/or any other base rubber or elastomer system may also be foamed, or filled with hollow microspheres or with expandable microspheres which expand at a set temperature during the curing process to any low specific gravity level. Other ingredients such as sulfur accelerators, e.g., tetra methylthiuram di, tri, or tetrasulfide, and/or metal-containing organosulfur components may also be used according to the invention. Suitable metal-containing organosulfur accelerators include, but are not limited to, cadmium, copper, lead, and tellurium analogs of diethyldithiocarbamate, diamyldithiocarbamate, and dimethyldithiocarbamate, or mixtures thereof. Other ingredients such as processing aids e.g., fatty acids and/or their metal salts, processing oils, dyes and pigments, as well as other additives known to one skilled in the art may also be used in the present invention in amounts sufficient to achieve the purpose for which they are typically used.
The ratio of antioxidant to initiator and the cure cycle temperatures and durations are some factors which control the surface hardness of each core layer and provide the inventive regions of varying hardness within each core layer.
Examples of suitable formulations for several embodiments of golf ball 10 as discussed herein are summarized in the following TABLE I:
TABLE I
Ranges
Components
Ranges
Outer Core
(phr)
Inner Core
A
B
C
ZDA
40-50
30-45
30-45
30-45
ZnO
5-10
5-10
5-10
5-10
BaSO 4
Vary to achieve targeted specific gravity
VANOX MBPC*
0.2-1.2
0
0-1.0
0.2-1.2
(Antioxidant)
TRIGONOX**
0.5-1.2
0
0.2-0.8
0.5-1.2
PERKADOX BC-FF***
—
0.5-1.0
0-1.0
0
Polybutadiene
100
100
100
100
Trans polyisoprene
0-15
0-15
0-15
0-15
ZnPCTP
0-3
0-3
0-3
0-3
Regrind
10-30
10-30
10-30
10-30
antioxidant/initiator ratio
0.33-4.8
0
0-10
0.33-4.8
Cure Temp. (° F.)
290° F.-315° F.
100° F.-150° F.
100° F.-150° F.
100° F.-150° F.
Cure Time T 1 (min)
15-25
1-3
1-3
1-3
Cure Temp. (° F.)
290° F.-315° F.
335° F.-365° F.
335° F.-365° F.
335° F.-365° F.
Cure Time T 2 (min)
—
9-14
9-14
9-14
Layer Diameter/Thickness(in)
0.75-1.25
0.14-0.415
0.14-0.415
0.14-0.415
Atti compression
—
75-100
75-100
75-100
COR @ 125 ft/s
—
0.795-0.825
0.795-0.825
0.795-0.825
The inventive cores of the invention may also include additional materials as disclosed herein.
Referring to FIG. 1 , golf ball 10 in accordance with the present invention is constructed to provide the desired spin profile and playing characteristics. In an embodiment as illustrated, golf ball 10 includes core 16 having core layers 17 and 18 and cover layer 15 surrounding core 16 . In one embodiment, the diameter of core 16 is greater than about 1.58 inches. Preferably, the diameter of core 16 is greater than about 1.6 inches. Core layers 17 and 18 represent the inner core layer and outer core layer, respectively, as disclosed and claimed herein.
FIGS. 2 and 3 illustrate several golf balls according to the invention. The inner core layer may have a hardness gradient represented by slope A, the outer core layer meanwhile having a hardness gradient represented by either of curves B, C or D. In each of these cases, the first hardness is located at the geometric center (0 mm from the center), the second and third hardnesses are located on the first outer surface and inner surface, respectively, about the vertical dotted line 10 mm to 15 mm from the geometric center. In FIGS. 2 and 3 , the second and third hardnesses are similar. The fourth hardness is located about 20 mm from the geometric center, and the fifth hardness appears between the third and fourth hardnesses in a region extending between about 10% and about 90% of the distance from the inner surface to the second outer surface. As discussed more fully throughout, each embodiment defines particular examples of possible hardness relationships between the first, second third, fourth and fifth hardnesses.
The surface hardness of a core is obtained from the average of a number of measurements taken from opposing hemispheres of a core, taking care to avoid making measurements on the parting line of the core or on surface defects, such as holes or protrusions. Hardness measurements are made pursuant to ASTM D-2240 “Indentation Hardness of Rubber and Plastic by Means of a Durometer.” Because of the curved surface of a core, care must be taken to insure that the core is centered under the durometer indentor before a surface hardness reading is obtained. A calibrated, digital durometer, capable of reading to 0.1 hardness units is used for all hardness measurements and is set to take hardness readings at 1 second after the maximum reading is obtained. The digital durometer must be attached to, and its foot made parallel to, the base of an automatic stand, such that the weight on the durometer and attack rate conform to ASTM D-2240.
To prepare a core for hardness gradient measurements, the core is gently pressed into a hemispherical holder having an internal diameter approximately slightly smaller than the diameter of the core, such that the core is held in place in the hemispherical portion of the holder while concurrently leaving the geometric central plane of the core exposed. The core is secured in the holder by friction, such that it will not move during the cutting and grinding steps, but the friction is not so excessive that distortion of the natural shape of the core would result. The core is secured such that the parting line of the core is roughly parallel to the top of the holder. The diameter of the core is measured 90 degrees to this orientation prior to securing. A measurement is also made from the bottom of the holder to the top of the core to provide a reference point for future calculations. A rough cut, made slightly above the exposed geometric center of the core using a band saw or other appropriate cutting tool, making sure that the core does not move in the holder during this step. The remainder of the core, still in the holder, is secured to the base plate of a surface grinding machine. The exposed ‘rough’ core surface is ground to a smooth, flat surface, revealing the geometric center of the core, which can be verified by measuring the height of the bottom of the holder to the exposed surface of the core, making sure that exactly half of the original height of the core, as measured above, has been removed to within ±0.004 inches.
Leaving the core in the holder, the center of the core is found with a center square and carefully marked and the hardness is measured at the center mark. Hardness measurements at any distance from the center of the core may be measured by drawing a line radially outward from the center mark, and measuring and marking the distance from the center, typically in 2-mm increments. All hardness measurements performed on the plane passing through the geometric center are performed while the core is still in the holder and without having disturbed its orientation, such that the test surface is constantly parallel to the bottom of the holder. The hardness difference from any predetermined location on the core (e.g., first outer surface, second outer surface, etc.) is calculated as the average hardness at the predetermined location minus the hardness at a chosen reference point at or closer to the geometric center than the predetermined location. For example, if the predetermined location is the second outer surface and is softer than its reference point, the inner surface, a negative hardness gradient results between the two points. Conversely, if inner surface is harder than the second outer surface, a positive hardness gradient results.
Golf ball compression remains an important factor to consider in maximizing playing performance. It affects the ball's spin rate off the driver as well as the feel. Initially, compression was referred to as the tightness of the windings around a golf ball. Today, compression refers to how much a ball will deform under a compressive force when a driver hits the ball. A ball actually tends to flatten out when a driver meets the ball; it deforms out of its round shape and then returns to its round shape, all in a second or two. Compression ratings of from about 70 to about 120 are common. The lower the compression rating, the more the ball will compress or deform upon impact.
People with a slower swing or slower club head speed will desire a ball having a lower compression rating. While the compression of a ball alone does not determine whether a ball flies farther—the club head speed actually determines that—compression can nevertheless influence or contribute to overall distance. For example, a golfer with a slower club head speed who uses a high compression ball will indeed lose yardage that would otherwise be achieved if that golfer used a low compression (or softer) ball. Accordingly, it is desirable to match golf ball compression rating with a player's swing speed in maximizing a golfer's performance on the green.
Several different methods can be used to measure compression, including Atti compression, Riehle compression, load/deflection measurements at a variety of fixed loads and offsets, and effective modulus. See, e.g., Compression by Any Other Name, Science and Golf IV, Proceedings of the World Scientific Congress of Golf (Eric Thain ed., Routledge, 2002) (“J. Dalton”) The term compression, as used herein, refers to Atti compression and is measured using an Atti compression test device. A piston compresses a ball against a spring and the piston remains fixed while deflection of the spring is measured at 1.25 mm (0.05 inches). Where a core has a very low stiffness, the compression measurement will be zero at 1.25 mm. In order to measure the compression of a core using an Atti compression tester, the core must be shimmed to a diameter of 1.680 inches because these testers are designed to measure objects having that diameter. Atti compression units can be converted to Riehle (cores), Riehle (balls), 100 kg deflection, 130-10 kg deflection or effective modulus using the formulas set forth in J. Dalton.
According to one aspect of the present invention, the golf ball is formulated to have a compression of between about 50 and about 120. In one embodiment, the compression of core 16 is greater than about 50. In another embodiment, the compression of core 16 is greater than about 70. In yet another embodiment, the compression of core 16 is from about 80 to about 100.
The distance that a golf ball would travel upon impact is a function of the coefficient of restitution (COR) and the aerodynamic characteristics of the ball. For golf balls, COR has been approximated as a ratio of the velocity of the golf ball after impact to the velocity of the golf ball prior to impact. The COR varies from 0 to 1.0. A COR value of 1.0 is equivalent to a perfectly elastic collision, that is, all the energy is transferred in the collision. A COR value of 0.0 is equivalent to a perfectly inelastic collision—that is, all of the energy is lost in the collision.
COR, as used herein, is determined by firing a golf ball or golf ball subassembly (e.g., a golf ball core) from an air cannon at two given velocities and calculating the COR at a velocity of 125 ft/s. Ball velocity is calculated as a ball approaches ballistic light screens which are located between the air cannon and a steel plate at a fixed distance. As the ball travels toward the steel plate, each light screen is activated, and the time at each light screen is measured. This provides an incoming transit time period inversely proportional to the ball's incoming velocity. The ball impacts the steel plate and rebounds through the light screens, which again measure the time period required to transit between the light screens. This provides an outgoing transit time period inversely proportional to the ball's outgoing velocity. COR is then calculated as the ratio of the outgoing transit time period to the incoming transit time period, COR=V out /V in =T in /T out . Preferably, a golf ball according to the present invention has a COR of at least about 0.78, more preferably, at least about 0.80.
The spin rate of a golf ball also remains an important golf ball characteristic. High spin rate allows skilled players more flexibility in stopping the ball on the green if they are able to control a high spin ball. On the other hand, recreational players often prefer a low spin ball since they do not have the ability to intentionally control the ball, and lower spin balls tend to drift less off the green.
Golf ball spin is dependent on variables including, for example, distribution of the density or specific gravity within a golf ball. For example, when the density or specific gravity is located in the golf ball center, a lower moment of inertia results which increases spin rate. Alternatively, when the density or specific gravity is concentrated in the outer regions of the golf ball, a higher moment of inertia results with a lower spin rate. The moment of inertia for a one piece ball that is 1.62 ounces and 1.68 inches in diameter is approximately 0.4572 oz-in 2 , which is the baseline moment of inertia value.
Accordingly, by varying the materials and the hardness of the regions of each core layer, different moments of inertia may be achieved for the golf ball of the present invention. In one embodiment, the resulting golf ball has a moment of inertia of from about to 0.440 to about 0.455 oz-in 2 . In another embodiment, the golf balls of the present invention have a moment of inertia of from about 0.456 oz-in 2 to about 0.470 oz-in 2 . In yet another embodiment, the golf ball has a moment of inertia of from about 0.450 oz-in 2 to about 0.460 oz-in 2 .
While the inventive golf ball may be formed from a variety of differing and conventional cover materials (both intermediate layer(s) and outer cover layer), preferred cover materials include, but are not limited to:
(1) Polyurethanes, such as those prepared from polyols or polyamines and diisocyanates or polyisocyanates and/or their prepolymers, and those disclosed in U.S. Pat. Nos. 5,334,673 and 6,506,851;
(2) Polyureas, such as those disclosed in U.S. Pat. Nos. 5,484,870 and 6,835,794; and
(3) Polyurethane-urea hybrids, blends or copolymers comprising urethane or urea segments.
Suitable polyurethane compositions comprise a reaction product of at least one polyisocyanate and at least one curing agent. The curing agent can include, for example, one or more polyamines, one or more polyols, or a combination thereof. The polyisocyanate can be combined with one or more polyols to form a prepolymer, which is then combined with the at least one curing agent. Thus, the polyols described herein are suitable for use in one or both components of the polyurethane material, i.e., as part of a prepolymer and in the curing agent. Suitable polyurethanes are described in U.S. Patent Application Publication No. 2005/0176523, which is incorporated by reference in its entirety.
Any polyisocyanate available to one of ordinary skill in the art is suitable for use according to the invention. Exemplary polyisocyanates include, but are not limited to, 4,4′-diphenylmethane diisocyanate (MDI); polymeric MDI; carbodiimide-modified liquid MDI; 4,4′-dicyclohexylmethane diisocyanate (H 12 MDI); p-phenylene diisocyanate (PPDI); m-phenylene diisocyanate (MPDI); toluene diisocyanate (TDI); 3,3′-dimethyl-4,4′-biphenylene diisocyanate; isophoronediisocyanate; 1,6-hexamethylene diisocyanate (HDI); naphthalene diisocyanate; xylene diisocyanate; p-tetramethylxylene diisocyanate; m-tetramethylxylene diisocyanate; ethylene diisocyanate; propylene-1,2-diisocyanate; tetramethylene-1,4-diisocyanate; cyclohexyl diisocyanate; dodecane-1,12-diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate; 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; methyl cyclohexylene diisocyanate; triisocyanate of HDI; triisocyanate of 2,4,4-trimethyl-1,6-hexane diisocyanate; tetracene diisocyanate; napthalene diisocyanate; anthracene diisocyanate; isocyanurate of toluene diisocyanate; uretdione of hexamethylene diisocyanate; and mixtures thereof. Polyisocyanates are known to those of ordinary skill in the art as having more than one isocyanate group, e.g., di-isocyanate, tri-isocyanate, and tetra-isocyanate. Preferably, the polyisocyanate includes MDI, PPDI, TDI, or a mixture thereof, and more preferably, the polyisocyanate includes MDI. It should be understood that, as used herein, the term MDI includes 4,4′-diphenylmethane diisocyanate, polymeric MDI, carbodiimide-modified liquid MDI, and mixtures thereof and, additionally, that the diisocyanate employed may be “low free monomer,” understood by one of ordinary skill in the art to have lower levels of “free” monomer isocyanate groups, typically less than about 0.1% free monomer isocyanate groups. Examples of “low free monomer” diisocyanates include, but are not limited to Low Free Monomer MDI, Low Free Monomer TDI, and Low Free Monomer PPDI.
The at least one polyisocyanate should have less than about 14% unreacted NCO groups. Preferably, the at least one polyisocyanate has no greater than about 8.0% NCO, more preferably no greater than about 7.8%, and most preferably no greater than about 7.5% NCO with a level of NCO of about 7.2 or 7.0, or 6.5% NCO commonly used.
Any polyol available to one of ordinary skill in the art is suitable for use according to the invention. Exemplary polyols include, but are not limited to, polyether polyols, hydroxy-terminated polybutadiene (including partially/fully hydrogenated derivatives), polyester polyols, polycaprolactone polyols, and polycarbonate polyols. In one preferred embodiment, the polyol includes polyether polyol. Examples include, but are not limited to, polytetramethylene ether glycol (PTMEG), polyethylene propylene glycol, polyoxypropylene glycol, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds and substituted or unsubstituted aromatic and cyclic groups. Preferably, the polyol of the present invention includes PTMEG.
In another embodiment, polyester polyols are included in the polyurethane material. Suitable polyester polyols include, but are not limited to, polyethylene adipate glycol; polybutylene adipate glycol; polyethylene propylene adipate glycol; o-phthalate-1,6-hexanediol; poly(hexamethylene adipate) glycol; and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups.
In another embodiment, polycaprolactone polyols are included in the materials of the invention. Suitable polycaprolactone polyols include, but are not limited to, 1,6-hexanediol-initiated polycaprolactone, diethylene glycol initiated polycaprolactone, trimethylol propane initiated polycaprolactone, neopentyl glycol initiated polycaprolactone, 1,4-butanediol-initiated polycaprolactone, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups.
In yet another embodiment, polycarbonate polyols are included in the polyurethane material of the invention. Suitable polycarbonates include, but are not limited to, polyphthalate carbonate and poly(hexamethylene carbonate) glycol. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. In one embodiment, the molecular weight of the polyol is from about 200 to about 4000.
Polyamine curatives are also suitable for use in the polyurethane composition of the invention and have been found to improve cut, shear, and impact resistance of the resultant balls. Preferred polyamine curatives include, but are not limited to, 3,5-dimethylthio-2,4-toluenediamine and isomers thereof 3,5-diethyltoluene-2,4-diamine and isomers thereof, such as 3,5-diethyltoluene-2,6-diamine; 4,4′-bis-(sec-butylamino)-diphenylmethane; 1,4-bis-(sec-butylamino)-benzene, 4,4′-methylene-bis-(2-chloroaniline); 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline); polytetramethyleneoxide-di-p-aminobenzoate; N,N′-dialkyldiamino diphenyl methane; p,p′-methylene dianiline; m-phenylenediamine; 4,4′-methylene-bis-(2-chloroaniline); 4,4′-methylene-bis-(2,6-diethylaniline); 4,4′-methylene-bis-(2,3-dichloroaniline); 4,4′-diamino-3,3′-diethyl-5,5′-dimethyl diphenylmethane; 2,2′,3,3′-tetrachloro diamino diphenylmethane; trimethylene glycol di-p-aminobenzoate; and mixtures thereof. Preferably, the curing agent of the present invention includes 3,5-dimethylthio-2,4-toluenediamine and isomers thereof, such as ETHACURE® 300, commercially available from Albermarle Corporation of Baton Rouge, La. Suitable polyamine curatives, which include both primary and secondary amines, preferably have molecular weights ranging from about 64 to about 2000.
At least one of a diol, triol, tetraol, or hydroxy-terminated curatives may be added to the aforementioned polyurethane composition. Suitable diol, triol, and tetraol groups include ethylene glycol; diethylene glycol; polyethylene glycol; propylene glycol; polypropylene glycol; lower molecular weight polytetramethylene ether glycol; 1,3-bis(2-hydroxyethoxy) benzene; 1,3-bis-[2-(2-hydroxyethoxy)ethoxy]benzene; 1,3-bis-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}benzene; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol; resorcinol-di-(β-hydroxyethyl)ether; hydroquinone-di-(β-hydroxyethyl)ether; and mixtures thereof. Preferred hydroxy-terminated curatives include 1,3-bis(2-hydroxyethoxy) benzene; 1,3-bis-[2-(2-hydroxyethoxy)ethoxy]benzene; 1,3-bis-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}benzene; 1,4-butanediol, and mixtures thereof. Preferably, the hydroxy-terminated curatives have molecular weights ranging from about 48 to 2000. It should be understood that molecular weight, as used herein, is the absolute weight average molecular weight and would be understood as such by one of ordinary skill in the art.
Both the hydroxy-terminated and amine curatives can include one or more saturated, unsaturated, aromatic, and cyclic groups. Additionally, the hydroxy-terminated and amine curatives can include one or more halogen groups. The polyurethane composition can be formed with a blend or mixture of curing agents. If desired, however, the polyurethane composition may be formed with a single curing agent.
In a preferred embodiment of the present invention, saturated polyurethanes are used to form one or more of the cover layers, preferably the outer cover layer, and may be selected from among both castable thermoset and thermoplastic polyurethanes.
In this embodiment, the saturated polyurethanes of the present invention are substantially free of aromatic groups or moieties. Saturated polyurethanes suitable for use in the invention are a product of a reaction between at least one polyurethane prepolymer and at least one saturated curing agent. The polyurethane prepolymer is a product formed by a reaction between at least one saturated polyol and at least one saturated diisocyanate. As is well known in the art, that a catalyst may be employed to promote the reaction between the curing agent and the isocyanate and polyol, or the curing agent and the prepolymer.
Saturated diisocyanates which can be used include, without limitation, ethylene diisocyanate; propylene-1,2-diisocyanate; tetramethylene-1,4-diisocyanate; 1,6-hexamethylene-diisocyanate (HDI); 2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylene diisocyanate; dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate; 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; isophorone diisocyanate; methyl cyclohexylene diisocyanate; triisocyanate of HDI; triisocyanate of 2,2,4-trimethyl-1,6-hexane diisocyanate. The most preferred saturated diisocyanates are 4,4′-dicyclohexylmethane diisocyanate and isophorone diisocyanate.
Saturated polyols which are appropriate for use in this invention include without limitation polyether polyols such as polytetramethylene ether glycol and poly(oxypropylene) glycol. Suitable saturated polyester polyols include polyethylene adipate glycol, polyethylene propylene adipate glycol, polybutylene adipate glycol, polycarbonate polyol and ethylene oxide-capped polyoxypropylene diols. Saturated polycaprolactone polyols which are useful in the invention include diethylene glycol-initiated polycaprolactone, 1,4-butanediol-initiated polycaprolactone, 1,6-hexanediol-initiated polycaprolactone; trimethylol propane-initiated polycaprolactone, neopentyl glycol initiated polycaprolactone, and polytetramethylene ether glycol-initiated polycaprolactone. The most preferred saturated polyols are polytetramethylene ether glycol and PTMEG-initiated polycaprolactone.
Suitable saturated curatives include 1,4-butanediol, ethylene glycol, diethylene glycol, polytetramethylene ether glycol, propylene glycol; trimethanolpropane; tetra-(2-hydroxypropyl)-ethylenediamine; isomers and mixtures of isomers of cyclohexyldimethylol, isomers and mixtures of isomers of cyclohexane bis(methylamine); triisopropanolamine; ethylene diamine; diethylene triamine; triethylene tetramine; tetraethylene pentamine; 4,4′-dicyclohexylmethane diamine; 2,2,4-trimethyl-1,6-hexanediamine; 2,4,4-trimethyl-1,6-hexanediamine; diethyleneglycol di-(aminopropyl)ether; 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 1,2-bis-(sec-butylamino)cyclohexane; 1,4-bis-(sec-butylamino) cyclohexane; isophorone diamine; hexamethylene diamine; propylene diamine; 1-methyl-2,4-cyclohexyl diamine; 1-methyl-2,6-cyclohexyl diamine; 1,3-diaminopropane; dimethylamino propylamine; diethylamino propylamine; imido-bis-propylamine; isomers and mixtures of isomers of diaminocyclohexane; monoethanolamine; diethanolamine; triethanolamine; monoisopropanolamine; and diisopropanolamine. The most preferred saturated curatives are 1,4-butanediol, 1,4-cyclohexyldimethylol and 4,4′-bis-(sec-butylamino)-dicyclohexylmethane.
Alternatively, other suitable polymers include partially or fully neutralized ionomer, metallocene, or other single-site catalyzed polymer, polyester, polyamide, non-ionomeric thermoplastic elastomer, copolyether-esters, copolyether-amides, polycarbonate, polybutadiene, polyisoprene, polystryrene block copolymers (such as styrene-butadiene-styrene), styrene-ethylene-propylene-styrene, styrene-ethylene-butylene-styrene, and the like, and blends thereof. Thermosetting polyurethanes or polyureas are suitable for the outer cover layers of the golf balls of the present invention.
Additionally, polyurethane can be replaced with or blended with a polyurea material. Polyureas are distinctly different from polyurethane compositions, but also result in desirable aerodynamic and aesthetic characteristics when used in golf ball components. The polyurea-based compositions are preferably saturated in nature.
Without being bound to any particular theory, it is now believed that substitution of the long chain polyol segment in the polyurethane prepolymer with a long chain polyamine oligomer soft segment to form a polyurea prepolymer, improves shear, cut, and resiliency, as well as adhesion to other components. Thus, the polyurea compositions of this invention may be formed from the reaction product of an isocyanate and polyamine prepolymer crosslinked with a curing agent. For example, polyurea-based compositions of the invention may be prepared from at least one isocyanate, at least one polyether amine, and at least one diol curing agent or at least one diamine curing agent.
Any polyamine available to one of ordinary skill in the art is suitable for use in the polyurea prepolymer. Polyether amines are particularly suitable for use in the prepolymer. As used herein, “polyether amines” refer to at least polyoxyalkyleneamines containing primary amino groups attached to the terminus of a polyether backbone. Due to the rapid reaction of isocyanate and amine, and the insolubility of many urea products, however, the selection of diamines and polyether amines is limited to those allowing the successful formation of the polyurea prepolymers. In one embodiment, the polyether backbone is based on tetramethylene, propylene, ethylene, trimethylolpropane, glycerin, and mixtures thereof.
Suitable polyether amines include, but are not limited to, methyldiethanolamine; polyoxyalkylenediamines such as, polytetramethylene ether diamines, polyoxypropylenetriamine, and polyoxypropylene diamines; poly(ethylene oxide capped oxypropylene) ether diamines; propylene oxide-based triamines; triethyleneglycoldiamines; trimethylolpropane-based triamines; glycerin-based triamines; and mixtures thereof. In one embodiment, the polyether amine used to form the prepolymer is JEFFAMINE® D2000 (manufactured by Huntsman Chemical Co. of Austin, Tex.).
The molecular weight of the polyether amine for use in the polyurea prepolymer may range from about 100 to about 5000. In one embodiment, the polyether amine molecular weight is about 200 or greater, preferably about 230 or greater. In another embodiment, the molecular weight of the polyether amine is about 4000 or less. In yet another embodiment, the molecular weight of the polyether amine is about 600 or greater. In still another embodiment, the molecular weight of the polyether amine is about 3000 or less. In yet another embodiment, the molecular weight of the polyether amine is between about 1000 and about 3000, and more preferably is between about 1500 to about 2500. Because lower molecular weight polyether amines may be prone to forming solid polyureas, a higher molecular weight oligomer, such as JEFFAMINE® D2000, is preferred.
As briefly discussed above, some amines may be unsuitable for reaction with the isocyanate because of the rapid reaction between the two components. In particular, shorter chain amines are fast reacting. In one embodiment, however, a hindered secondary diamine may be suitable for use in the prepolymer. Without being bound to any particular theory, it is believed that an amine with a high level of stearic hindrance, e.g., a tertiary butyl group on the nitrogen atom, has a slower reaction rate than an amine with no hindrance or a low level of hindrance. For example, 4,4′-bis-(sec-butylamino)-dicyclohexylmethane (CLEARLINK® 1000) may be suitable for use in combination with an isocyanate to form the polyurea prepolymer.
Any isocyanate available to one of ordinary skill in the art is suitable for use in the polyurea prepolymer. Isocyanates for use with the present invention include aliphatic, cycloaliphatic, araliphatic, aromatic, any derivatives thereof, and combinations of these compounds having two or more isocyanate (NCO) groups per molecule. The isocyanates may be organic polyisocyanate-terminated prepolymers. The isocyanate-containing reactable component may also include any isocyanate-functional monomer, dimer, trimer, or multimeric adduct thereof, prepolymer, quasi-prepolymer, or mixtures thereof. Isocyanate-functional compounds may include monoisocyanates or polyisocyanates that include any isocyanate functionality of two or more.
Suitable isocyanate-containing components include diisocyanates having the generic structure: O═C═N—R—N═C═O, where R is preferably a cyclic, aromatic, or linear or branched hydrocarbon moiety containing from about 1 to about 20 carbon atoms. The diisocyanate may also contain one or more cyclic groups or one or more phenyl groups. When multiple cyclic or aromatic groups are present, linear and/or branched hydrocarbons containing from about 1 to about 10 carbon atoms can be present as spacers between the cyclic or aromatic groups. In some cases, the cyclic or aromatic group(s) may be substituted at the 2-, 3-, and/or 4-positions, or at the ortho-, meta-, and/or para-positions, respectively. Substituted groups may include, but are not limited to, halogens, primary, secondary, or tertiary hydrocarbon groups, or a mixture thereof.
Examples of diisocyanates that can be used with the present invention include, but are not limited to, substituted and isomeric mixtures including 2,2′-, 2,4′-, and 4,4′-diphenylmethane diisocyanate; 3,3′-dimethyl-4,4′-biphenylene diisocyanate; toluene diisocyanate; polymeric MDI; carbodiimide-modified liquid 4,4′-diphenylmethane diisocyanate; para-phenylene diisocyanate; meta-phenylene diisocyanate; triphenyl methane-4,4′- and triphenyl methane-4,4′-triisocyanate; naphthylene-1,5-diisocyanate; 2,4′-, 4,4′-, and 2,2-biphenyl diisocyanate; polyphenyl polymethylene polyisocyanate; mixtures of MDI and PMDI; mixtures of PMDI and TDI; ethylene diisocyanate; propylene-1,2-diisocyanate; tetramethylene-1,2-diisocyanate; tetramethylene-1,3-diisocyanate; tetramethylene-1,4-diisocyanate; 1,6-hexamethylene-diisocyanate; octamethylene diisocyanate; decamethylene diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylene diisocyanate; dodecane-1,12-diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,2-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate; methyl-cyclohexylene diisocyanate; 2,4-methylcyclohexane diisocyanate; 2,6-methylcyclohexane diisocyanate; 4,4′-dicyclohexyl diisocyanate; 2,4′-dicyclohexyl diisocyanate; 1,3,5-cyclohexane triisocyanate; isocyanatomethylcyclohexane isocyanate; 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; isocyanatoethylcyclohexane isocyanate; bis(isocyanatomethyl)-cyclohexane diisocyanate; 4,4′-bis(isocyanatomethyl) dicyclohexane; 2,4′-bis(isocyanatomethyl) dicyclohexane; isophorone diisocyanate; triisocyanate of HDI; triisocyanate of 2,2,4-trimethyl-1,6-hexane diisocyanate; 4,4′-dicyclohexylmethane diisocyanate; 2,4-hexahydrotoluene diisocyanate; 2,6-hexahydrotoluene diisocyanate; 1,2-, 1,3-, and 1,4-phenylene diisocyanate; aromatic aliphatic isocyanate, such as 1,2-, 1,3-, and 1,4-xylene diisocyanate; meta-tetramethylxylene diisocyanate; para-tetramethylxylene diisocyanate; trimerized isocyanurate of any polyisocyanate, such as isocyanurate of toluene diisocyanate, trimer of diphenylmethane diisocyanate, trimer of tetramethylxylene diisocyanate, isocyanurate of hexamethylene diisocyanate, isocyanurate of isophorone diisocyanate, and mixtures thereof; dimerized uredione of any polyisocyanate, such as uretdione of toluene diisocyanate, uretdione of hexamethylene diisocyanate, and mixtures thereof; modified polyisocyanate derived from the above isocyanates and polyisocyanates; and mixtures thereof.
Examples of saturated diisocyanates that can be used with the present invention include, but are not limited to, ethylene diisocyanate; propylene-1,2-diisocyanate; tetramethylene diisocyanate; tetramethylene-1,4-diisocyanate; 1,6-hexamethylene-diisocyanate; octamethylene diisocyanate; decamethylene diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylene diisocyanate; dodecane-1,12-diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,2-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate; methyl-cyclohexylene diisocyanate; 2,4-methylcyclohexane diisocyanate; 2,6-methylcyclohexane diisocyanate; 4,4′-dicyclohexyl diisocyanate; 2,4′-dicyclohexyl diisocyanate; 1,3,5-cyclohexane triisocyanate; isocyanatomethylcyclohexane isocyanate; 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; isocyanatoethylcyclohexane isocyanate; bis(isocyanatomethyl)-cyclohexane diisocyanate; 4,4′-bis(isocyanatomethyl) dicyclohexane; 2,4′-bis(isocyanatomethyl) dicyclohexane; isophorone diisocyanate; triisocyanate of HDI; triisocyanate of 2,2,4-trimethyl-1,6-hexane diisocyanate; 4,4′-dicyclohexylmethane diisocyanate; 2,4-hexahydrotoluene diisocyanate; 2,6-hexahydrotoluene diisocyanate; and mixtures thereof. Aromatic aliphatic isocyanates may also be used to form light stable materials. Examples of such isocyanates include 1,2-, 1,3-, and 1,4-xylene diisocyanate; meta-tetramethylxylene diisocyanate; para-tetramethylxylene diisocyanate; trimerized isocyanurate of any polyisocyanate, such as isocyanurate of toluene diisocyanate, trimer of diphenylmethane diisocyanate, trimer of tetramethylxylene diisocyanate, isocyanurate of hexamethylene diisocyanate, isocyanurate of isophorone diisocyanate, and mixtures thereof; dimerized uredione of any polyisocyanate, such as uretdione of toluene diisocyanate, uretdione of hexamethylene diisocyanate, and mixtures thereof; modified polyisocyanate derived from the above isocyanates and polyisocyanates; and mixtures thereof. In addition, the aromatic aliphatic isocyanates may be mixed with any of the saturated isocyanates listed above for the purposes of this invention.
The number of unreacted NCO groups in the polyurea prepolymer of isocyanate and polyether amine may be varied to control such factors as the speed of the reaction, the resultant hardness of the composition, and the like. For instance, the number of unreacted NCO groups in the polyurea prepolymer of isocyanate and polyether amine may be less than about 14 percent. In one embodiment, the polyurea prepolymer has from about 5 percent to about 11 percent unreacted NCO groups, and even more preferably has from about 6 to about 9.5 percent unreacted NCO groups. In one embodiment, the percentage of unreacted NCO groups is about 3 percent to about 9 percent. Alternatively, the percentage of unreacted NCO groups in the polyurea prepolymer may be about 7.5 percent or less, and more preferably, about 7 percent or less. In another embodiment, the unreacted NCO content is from about 2.5 percent to about 7.5 percent, and more preferably from about 4 percent to about 6.5 percent.
When formed, polyurea prepolymers may contain about 10 percent to about 20 percent by weight of the prepolymer of free isocyanate monomer. Thus, in one embodiment, the polyurea prepolymer may be stripped of the free isocyanate monomer. For example, after stripping, the prepolymer may contain about 1 percent or less free isocyanate monomer. In another embodiment, the prepolymer contains about 0.5 percent by weight or less of free isocyanate monomer.
The polyether amine may be blended with additional polyols to formulate copolymers that are reacted with excess isocyanate to form the polyurea prepolymer. In one embodiment, less than about 30 percent polyol by weight of the copolymer is blended with the saturated polyether amine. In another embodiment, less than about 20 percent polyol by weight of the copolymer, preferably less than about 15 percent by weight of the copolymer, is blended with the polyether amine. The polyols listed above with respect to the polyurethane prepolymer, e.g., polyether polyols, polycaprolactone polyols, polyester polyols, polycarbonate polyols, hydrocarbon polyols, other polyols, and mixtures thereof, are also suitable for blending with the polyether amine. The molecular weight of these polymers may be from about 200 to about 4000, but also may be from about 1000 to about 3000, and more preferably are from about 1500 to about 2500.
The polyurea composition can be formed by crosslinking the polyurea prepolymer with a single curing agent or a blend of curing agents. The curing agent of the invention is preferably an amine-terminated curing agent, more preferably a secondary diamine curing agent so that the composition contains only urea linkages. In one embodiment, the amine-terminated curing agent may have a molecular weight of about 64 or greater. In another embodiment, the molecular weight of the amine-curing agent is about 2000 or less. As discussed above, certain amine-terminated curing agents may be modified with a compatible amine-terminated freezing point depressing agent or mixture of compatible freezing point depressing agents
Suitable amine-terminated curing agents include, but are not limited to, ethylene diamine; hexamethylene diamine; 1-methyl-2,6-cyclohexyl diamine; tetrahydroxypropylene ethylene diamine; 2,2,4- and 2,4,4-trimethyl-1,6-hexanediamine; 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 1,4-bis-(sec-butylamino)-cyclohexane; 1,2-bis-(sec-butylamino)-cyclohexane; derivatives of 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 4,4′-dicyclohexylmethane diamine; 1,4-cyclohexane-bis-(methylamine); 1,3-cyclohexane-bis-(methylamine); diethylene glycol di-(aminopropyl)ether; 2-methylpentamethylene-diamine; diaminocyclohexane; diethylene triamine; triethylene tetramine; tetraethylene pentamine; propylene diamine; 1,3-diaminopropane; dimethylamino propylamine; diethylamino propylamine; dipropylene triamine; imido-bis-propylamine; monoethanolamine, diethanolamine; triethanolamine; monoisopropanolamine, diisopropanolamine; isophoronediamine; 4,4′-methylenebis-(2-chloroaniline); 3,5; dimethylthio-2,4-toluenediamine; 3,5-dimethylthio-2,6-toluenediamine; 3,5-diethylthio-2,4-toluenediamine; 3,5; diethylthio-2,6-toluenediamine; 4,4′-bis-(sec-butylamino)-diphenylmethane and derivatives thereof; 1,4-bis-(sec-butylamino)-benzene; 1,2-bis-(sec-butylamino)-benzene; N,N′-dialkylamino-diphenylmethane; N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylene diamine; trimethyleneglycol-di-p-aminobenzoate; polytetramethyleneoxide-di-p-aminobenzoate; 4,4′-methylenebis-(3-chloro-2,6-diethyleneaniline); 4,4′-methylenebis-(2,6-diethylaniline); meta-phenylenediamine; paraphenylenediamine; and mixtures thereof. In one embodiment, the amine-terminated curing agent is 4,4′-bis-(sec-butylamino)-dicyclohexylmethane.
Suitable saturated amine-terminated curing agents include, but are not limited to, ethylene diamine; hexamethylene diamine; 1-methyl-2,6-cyclohexyl diamine; tetrahydroxypropylene ethylene diamine; 2,2,4- and 2,4,4-trimethyl-1,6-hexanediamine; 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 1,4-bis-(sec-butylamino)-cyclohexane; 1,2-bis-(sec-butylamino)-cyclohexane; derivatives of 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 4,4′-dicyclohexylmethane diamine; 4,4′-methylenebis-(2,6-diethylaminocyclohexane; 1,4-cyclohexane-bis-(methylamine); 1,3-cyclohexane-bis-(methylamine); diethylene glycol di-(aminopropyl)ether; 2-methylpentamethylene-diamine; diaminocyclohexane; diethylene triamine; triethylene tetramine; tetraethylene pentamine; propylene diamine; 1,3-diaminopropane; dimethylamino propylamine; diethylamino propylamine; imido-bis-propylamine; monoethanolamine, diethanolamine; triethanolamine; monoisopropanolamine, diisopropanolamine; isophoronediamine; triisopropanolamine; and mixtures thereof. In addition, any of the polyether amines listed above may be used as curing agents to react with the polyurea prepolymers.
Cover layers of the inventive golf ball may also be formed from ionomeric polymers, preferably highly-neutralized ionomers (HNP). In a preferred embodiment, at least one intermediate layer of the golf ball is formed from an HNP material or a blend of HNP materials. The acid moieties of the HNP's, typically ethylene-based ionomers, are preferably neutralized greater than about 70%, more preferably greater than about 90%, and most preferably at least about 100%. The HNP's can be also be blended with a second polymer component, which, if containing an acid group, may be neutralized in a conventional manner, by the organic fatty acids of the present invention, or both. The second polymer component, which may be partially or fully neutralized, preferably comprises ionomeric copolymers and terpolymers, ionomer precursors, thermoplastics, polyamides, polycarbonates, polyesters, polyurethanes, polyureas, thermoplastic elastomers, polybutadiene rubber, balata, metallocene-catalyzed polymers (grafted and non-grafted), single-site polymers, high-crystalline acid polymers, cationic ionomers, and the like. HNP polymers typically have a material hardness of between about 20 and about 80 Shore D, and a flexural modulus of between about 3,000 psi and about 200,000 psi.
In one embodiment of the present invention the HNP's are ionomers and/or their acid precursors that are preferably neutralized, either fully or partially, with organic acid copolymers or the salts thereof. The acid copolymers are preferably α-olefin, such as ethylene, C 3-8 α,β-ethylenically unsaturated carboxylic acid, such as acrylic and methacrylic acid, copolymers. They may optionally contain a softening monomer, such as alkyl acrylate and alkyl methacrylate, wherein the alkyl groups have from 1 to 8 carbon atoms.
The acid copolymers can be described as E/X/Y copolymers where E is ethylene, X is an α,β-ethylenically unsaturated carboxylic acid, and Y is a softening comonomer. In a preferred embodiment, X is acrylic or methacrylic acid and Y is a C 1-8 alkyl acrylate or methacrylate ester. X is preferably present in an amount from about 1 to about 35 weight percent of the polymer, more preferably from about 5 to about 30 weight percent of the polymer, and most preferably from about 10 to about 20 weight percent of the polymer. Y is preferably present in an amount from about 0 to about 50 weight percent of the polymer, more preferably from about 5 to about 25 weight percent of the polymer, and most preferably from about 10 to about 20 weight percent of the polymer.
Specific acid-containing ethylene copolymers include, but are not limited to, ethylene/acrylic acid/n-butyl acrylate, ethylene/methacrylic acid/n-butyl acrylate, ethylene/methacrylic acid/iso-butyl acrylate, ethylene/acrylic acid/iso-butyl acrylate, ethylene/methacrylic acid/n-butyl methacrylate, ethylene/acrylic acid/methyl methacrylate, ethylene/acrylic acid/methyl acrylate, ethylene/methacrylic acid/methyl acrylate, ethylene/methacrylic acid/methyl methacrylate, and ethylene/acrylic acid/n-butyl methacrylate. Preferred acid-containing ethylene copolymers include, ethylene/methacrylic acid/n-butyl acrylate, ethylene/acrylic acid/n-butyl acrylate, ethylene/methacrylic acid/methyl acrylate, ethylene/acrylic acid/ethyl acrylate, ethylene/methacrylic acid/ethyl acrylate, and ethylene/acrylic acid/methyl acrylate copolymers. The most preferred acid-containing ethylene copolymers are, ethylene/(meth) acrylic acid/n-butyl, acrylate, ethylene/(meth)acrylic acid/ethyl acrylate, and ethylene/(meth) acrylic acid/methyl acrylate copolymers.
Ionomers are typically neutralized with a metal cation, such as Li, Na, Mg, K, Ca, or Zn. It has been found that by adding sufficient organic acid or salt of organic acid, along with a suitable base, to the acid copolymer or ionomer, however, the ionomer can be neutralized, without losing processability, to a level much greater than for a metal cation. Preferably, the acid moieties are neutralized greater than about 80%, preferably from 90-100%, most preferably 100% without losing processability. This accomplished by melt-blending an ethylene α,β-ethylenically unsaturated carboxylic acid copolymer, for example, with an organic acid or a salt of organic acid, and adding a sufficient amount of a cation source to increase the level of neutralization of all the acid moieties (including those in the acid copolymer and in the organic acid) to greater than 90%, (preferably greater than 100%).
The organic acids of the present invention are aliphatic, mono- or multi-functional (saturated, unsaturated, or multi-unsaturated) organic acids. Salts of these organic acids may also be employed. The salts of organic acids of the present invention include the salts of barium, lithium, sodium, zinc, bismuth, chromium, cobalt, copper, potassium, strontium, titanium, tungsten, magnesium, cesium, iron, nickel, silver, aluminum, tin, or calcium, salts of fatty acids, particularly stearic, behenic, erucic, oleic, linoelic or dimerized derivatives thereof. It is preferred that the organic acids and salts of the present invention be relatively non-migratory (they do not bloom to the surface of the polymer under ambient temperatures) and non-volatile (they do not volatilize at temperatures required for melt-blending).
The ionomers of the invention may also be more conventional ionomers, i.e., partially-neutralized with metal cations. The acid moiety in the acid copolymer is neutralized about 1 to about 90%, preferably at least about 20 to about 75%, and more preferably at least about 40 to about 70%, to form an ionomer, by a cation such as lithium, sodium, potassium, magnesium, calcium, barium, lead, tin, zinc, aluminum, or a mixture thereof.
A moisture vapor barrier layer, such as disclosed in U.S. Pat. Nos. 6,632,147; 6,932,720; 7,004,854; and 7,182,702, all of which are incorporated by reference herein in their entirety, are optionally employed between the cover layer and the core. The moisture barrier layer may be disposed between the outer core layer and the cover layer. The moisture vapor barrier protects the inner and outer cores from degradation due to exposure to moisture, for example water, and extends the usable life of the golf ball. The moisture vapor transmission rate of the moisture barrier layer is selected to be less than the moisture vapor transmission rate of the cover layer. The moisture barrier layer has a specific gravity of from about 1.1 to about 1.2 and a thickness of less than about 0.03 inches. Suitable materials for the moisture barrier layer include a combination of a styrene block copolymer and a flaked metal, for example aluminum flake.
Unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for amounts of materials, and others in the specification may be read as if prefaced by the word “about” even though the term “about” may not expressly appear with the value, amount or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Furthermore, when numerical ranges of varying scope are set forth herein, it is contemplated that any combination of these values inclusive of the recited values may be used.
While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the preferred embodiments of the present invention, it is appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Examples of such modifications include reasonable variations of the numerical values and/or materials and/or components discussed above. Hence, the numerical values stated above and claimed below specifically include those values and the values that are approximate to those stated and claimed values. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments, which would come within the spirit and scope of the present invention.
The invention described and claimed herein is not to be limited in scope by the specific embodiments herein disclosed, since these embodiments are intended as illustrations of several aspects of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. For example, the compositions of the present invention may be used in a variety of equipment. Such modifications are also intended to fall within the scope of the appended claims.
While any of the embodiments herein may have any known dimple number and pattern, a preferred number of dimples is 252 to 456, and more preferably is 330 to 392. The dimples may comprise any width, depth, and edge angle disclosed in the prior art and the patterns may comprises multitudes of dimples having different widths, depths and edge angles. The parting line configuration of said pattern may be either a straight line or a staggered wave parting line (SWPL). Most preferably the dimple number is 330, 332, or 392 and comprises 5 to 7 dimples sizes and the parting line is a SWPL.
In any of these embodiments the single-layer core may be replaced with a 2 or more layer core wherein at least one core layer has a negative hardness gradient. Other than in the operating examples, or unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for amounts of materials and others in the specification may be read as if prefaced by the word “about” even though the term “about” may not expressly appear with the value, amount or range.
Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the objective stated above, it is appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments, which would come within the spirit and scope of the present invention.
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The present invention is directed to an improved multi-layered core golf ball wherein each core layer comprises its own specific hardness gradient (positive, negative or a combination) in addition to an overall specific hardness gradient from one core layer to the next.
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BACKGROUND OF THE INVENTION
The present invention relates to the measurement of unknown properties of materials, such as moisture content or dielectric constant, using microwaves and in particular to the measurement of the moisture content of a material by transmitting microwave beams through such material so that a portion of the beam energy is absorbed by the moisture or other property. This percent moisture measurement is achieved with good accuracy in spite of the presence in the test material of another microwave absorbing property or component in variable amounts, by measuring attenuation using two microwave signals of different frequency and determination of the density of the test material by measuring the phase shift of the received signal produced by one of such signals when its corresponding microwave beam is transmitted through the test material. The invention also includes a microwave antenna with two microwave signal connections for the two different frequency signals properly positioned in order to efficiently transmit or receive two microwave beams of different frequency with the same antenna without interference.
The present invention is especially useful in measuring the moisture content of foundry molding sand and coal. In the previous U.S. Pat. Nos. 3,696,079, 3,818,333 and 4,475,080 of Charles W. E. Walker issued Sept. 19, 1972, June 18, 1974 and Oct. 2, 1984, respectively, and in the paper "Instrumentation for the On Stream Analysis of Ash Content and Moisture Content in Coal Cleaning Plants" by Gunter Fauth, et al, published at the annual meeting of S.M.E. and A.I.M.E. at Los Angeles, Calif. Feb. 26 to Mar. 1, 1984, microwave moisture measurement apparatus is disclosed. However, these prior apparatus do not employ two microwave beams of different frequency to determine the amount of moisture attenuation of the microwave beams by the test material, and do not measure the phase shift of one of the two attenuated received microwave signals to determine test material density for measurement of the percent of moisture content, in the manner of the present invention. In addition, they do not show a microwave antenna which is capable of transmitting or receiving two microwave beams of different frequency at the same time without interference in the manner of the invention.
The invention is directed to the accurate measurement of the moisture content of a wide range of solid and liquid materials. In the above noted patents, it is shown that the absorption of microwave energy from a microwave beam transmitted through the material is capable of providing accurate information on its moisture content. The present inventor has found, however, that in all materials there are interfering effects or other factors present in the material, in addition to the amount of water present, which affect the microwave absorption.
All substances in the dry state produce some microwave absorption. In some, this microwave absorption is constant but in many of the materials which are industrially important, it is not constant and must be measured by an independent means if accurate measurement of moisture is to be obtained. In some cases, for example, the dry attenuation of the microwave is due to the dry substance being electrically conductive. If this is true in the macroscopic sense, the substance is probably not amenable to measurement by microwaves but many substances such as foundry molding sand and most coals are not electrically conducting in the macroscopic sense, yet contain microscopic particles or aggregates of atoms which are conductive and which, as a result, attenuate a microwave signal passed through the substance. In the case of both coal and foundry sand, this observed dry attenuation is thought to be due to elemental carbon particles, possibly in the form of small graphite crystalites. Finely divided metallic particles could have the same effect. Whatever the cause, the microwave attenuation due to such electrical conductivity is not frequency dependent, and so is markedly different from the water resonant absorption. The same is true of ionic conductivity which is another form of electrical conductivity and may arise from the presence of salts or of acids or bases in the substance being measured since any of these will dissolve in any water which is present to produce ions. Ionic conductivity will not contribute to dry attenuation but will affect the microwave attenuation so as to add to the moisture sensitivity in proportion to the ionic concentration. If this electrical conductivity of the dry material is not constant or the ionic concentration varies, then an independent measurement is needed to account for it if accurate moisture measurement is to be obtained.
In the microwave method of moisture measurement, the microwaves are passed through the test material and therefore sense a certain volume of material and are absorbed in proportion to the number of water molecules in that sense volume. The measurement signal is therefore proportional to the mass of water per unit volume in the material. To express this as percent water requires that the mass of material in the volume sensed be known. This may require a measurement of both the thickness of material through which the microwaves are passed and the density of the material in that volume.
Yet another factor which affects the microwave moisture measurement readings is that some of the water present becomes bonded to the material. This bonding may be chemical, such as hydrogen bonds or may be physical, as for example Van der Waals' forces. In either case, the water molecules so bonded are not free to rotate as free molecules and so do not exhibit the resonant interaction with microwaves. Except for hydrogen bonding of water to celulose and starch molecules which produce a square law relationship between microwave attenuation and percent water, I have found that almost all substances exhibit an interaction which appears to be a surface bonding phenomenon because it is dependent on particle size and particularly on the finest particles present. Thus, in pure silica sand there is effectively no bonding to a coarse grade but over 1 percent water bonds to 32 mesh grade sand. The net effect of the bonding in most substances, other than the organic ones mentioned above, is to halve the microwave attenuation up to the saturation level at which all the available bonds are satisfied. Beyond this point the attenuation becomes normal. For accurate moisture measurement through this saturation level, it is necessary that this level be known and that it be measured if it is not constant. This generally requires a knowledge of the fines content. Thus, in foundry molding sand it is the finely powdered Bentonite clay which establishes this level.
To eliminate these disturbing factors and for accurate moisture measurement, it is essential therefore that at least three independent mesurements be made. Only in special cases, can some of these be replaced with constant subtractors or divisors or by periodic manual adjustments as, for example when lower accuracy is acceptable, or when measuring some substances such as ammonium phosphate fertilizer in which the ionic conductivity is directly proportional to the amount of water present and so may be accounted for by a constant calibrating factor. In some other cases where moisture determination is only required over a limited range of moisture which is known to be either wholly below or wholly above the level at which bonding is saturated, it may not be necessary to measure this level.
It is therefore the specific purpose of this invention to provide the additional independent measurement means, in addition to the simple microwave attenuation, which are needed as stated above to provide accurate moisture measurement.
The present inventor has determined that the effect of dry attenuation can be eliminated by making microwave attenuation measurements at two different microwave frequencies. Because this dry attenuation is not frequency sensitive, the difference between the attenuation signals at the two different microwave frequencies is independent of the dry attenuation and depends only on the water present. This dual frequency measurement also eliminates the effect of variations in ionic conductivity when this is a concern. It is perhaps worth noting that there are some special cases such as alcohol and heavy water in which dry attenuation is frequency sensitive because these substances have their own resonant interaction with microwaves within the frequency range used for moisture measurement; clearly however, for this reason, microwaves cannot in any case be used to measure moisture in such substances unless another water resonance is available which is free of this restriction.
The present inventor has also determined that the density of the material in the microwave path can be measured using the same microwave beam as is used for one of the attenuation measurements by determining the change of phase of the microwave signal as it passes through the material. Like the attenuation, the phase change is a function of both the quantity of material in the microwave path and its content, but it is a different function so that both density and percent water can be computed. In effect, attenuation is proportional to the imaginary part of the dielectric constant ε 2 of the material and phase change proportional to the real part ε 1 .
The dielectric constant ε of any material is a complex quantity as expressed by the equation:
ε=ε.sub.1 +iε.sub.2
Where i is the square root of minus one. Both ε 1 and ε 2 are functions of both density and water content so that if density is constant, either attenuation or phase change could be used to measure percent water, but because the water resonance principally affects ε 2 it is more sensitive to water and therefore generally preferred, particularly at low moisture levels. In the same way, at low moisture levels, ε 1 is more dependent on density than on water content. Nevertheless, phase change can be preferred in some cases for moisture measurement, particularly when electrical conductivity effects are strong because these do not affect ε 1 and so do not interfere with phase change measurement.
The thickness of material through which the microwaves are passed is often arranged to be held constant by the geometry of the sensing system but where this thickness does vary it can readily be measured by a variety of well known means such as by a linear resistive transducer or by a linear variable differential transformer.
The bonding saturation level is only required to be known where moisture measurements are required to be made through this level because it is only under those cicumstances that two different moisture sensitivity slopes have to be used and their change over point must be known. The bonding saturation level is almost wholly dependent on the fines content of the material which, in many cases, is contributed by a single component of a mixture and the quantity of that component is known or can readily be measured by a standard technique. For example, in foundry molding sand it is the Bentonite clay which contributes the fines content and controls the bonding saturation level and a standard procedure exists for its determination.
It is also a significant part of this invention that if the measurement of the microwave phase change is not needed to determine the material density because the density is constant or is otherwise known, the phase signal can be used to measure bonding because bound water contributes the same as free water to ε 1 but not to ε 2 , whence the microwave phase change is a function of total water, whereas microwave attenuation is a function only of free water.
The application of these ideas, leading to accurate moisture measurement is perhaps best understood by considering one specific case which will illustrate the method and has proved to be highly successful, namely the measurement of moisture in foundry molding sand. When the dry ingredients of such molding sand are first mixed, they cause only small microwave attenuation, but on coming in contact with hot iron, changes are produced so that when the sand is returned for re-use and its moisture content measured, it is found to attenuate the microwaves quite strongly, even when bone dry. This dry sand attenuation has been found to vary, in some cases considerably, from one batch of sand to another. The dry attenuation is, however, found to be independent of microwave frequency, at least over a two to one frequency range as for example between 10.7 GHz and 5.8 GHz and 2.45 GHz. The difference in the attenuations at the two frequencies is therefore independent of the dry sand attenuation and a function only of the water present. It is a function of the water present per unit volume and to present this as percent water it is necessary to divide by the sand density. Now the purpose for which the sand is used requires that it be highly compactable when prepared for use as molding sand. To achieve this, Bentonite clay is added to the sand which has the property that it swells when brought in contact with water. The density of foundry sand is therefore not constant and density measurement is necessary for accurate moisture determination by microwaves.
The bonding saturation level of the water in foundry sand is certainly dependent on the amount of Bentonite clay which is present in the mix, but so is the performance of the sand in its molding function; it is therefore the practice in all foundries to ensure that this is maintained and fresh Bentonite clay is added to achieve this. Provided the water measurement on return sand is done after the Bentonite clay has been so added as required, the bonding saturation level will be above the level of moisture occurring in the return sand so that measurement of this return sand by microwaves will not be affected by the bonding saturation level.
Thus, means to develop two microwave attenuation signals and one phase signal are necessary for accurate moisture measurement in foundry sand.
SUMMARY OF INVENTION
It is therefore one object of the present invention to provide a microwave measurement apparatus for accurately measuring an unknown property of a test material.
Another object of the invention is to provide an improved microwave moisture measurement apparatus which is capable of accurate measurement of moisture content of a test material in the presence of another variable component which is highly absorbent of microwave energy.
A further object of the invention is to provide such an improved moisture measurement apparatus which employs two microwave signals of different frequencies to compensate for the other variable component in the test material.
An additional object of the invention is to provide such an improved moisture measurement apparatus which is capable of accurate measurement of the percent of moisture content even though the density of the test material varies by determining the phase shift of the received signal produced by a microwave beam transmitted through such test material.
Still another object of the invention is to provide an improved microwave antenna which is capable of efficiently transmitting or receiving two microwave beams of different frequencies without appreciable interference.
A still further object of the invention is to provide such an improved microwave moisture measurement apparatus employing such an improved antenna for accurate measurement of the moisture content of test material in an efficient manner with a compact apparatus.
BRIEF DESCRIPTION OF DRAWINGS
Other objects and advantages of the present invention will be apparent from the following detailed description of a preferred embodiment thereof and from the attached drawings of which:
FIG. 1 is a side elevation view of the dual frequency antenna developed for use in an embodiment of the present invention with parts broken away for clarity;
FIG. 1A is a partial elevation view taken along the line 1A--1A of FIG. 1;
FIG. 2 is a schematic diagram showing the electrical circuit for the measurement of microwave attenuation by moisture in a test material at two different microwave frequencies to determine moisture content in one embodiment of the present invention;
FIG. 3 is a schematic diagram showing the electrical circuit for measurement of the phase shift of a received microwave signal to determine the density of the test material, and to combine it with the attenuation measurements of FIG. 2 in order to determine the percent of moisture content in a second embodiment of the microwave moisture measurement apparatus of the present invention;
FIG. 4 shows the electrical signal produced at test point TP 1 in FIG. 3, plotted through one 360° phase sweep of the phase shifter of FIG. 3;
FIG. 5 shows the electrical signal produced at TP 2 in FIG. 3, plotted through the same 360° phase sweep of FIG. 4;
FIG. 6 shows the electrical pulse produced at TP 3 in FIG. 3, and the ramp voltage produced by the ramp generator of FIG. 3; and
FIG. 7 shows the electrical signal produced at TP 4 in FIG. 3 shown on the same time scale as the signals of FIG. 6.
DESCRIPTION OF PREFERRED EMBODIMENTS
In order to obtain accurate microwave measurement of moisture it has been found to be necessary, in most test materials to make two attenuation measurements with two different microwave frequencies simultaneously and to measure changes in the phase shift at one of them thereby giving three independent measurement signals which are suitably combined in a data processor such as an analog or digital computer to give the moisture content percentage. These measurements are done on test material 1, such as foundry sand, supported in a testing station 2 surrounded by microwave shields 3 such as by transporting such test material on a conveyor belt 4 through such testing station. Two microwave antennas are provided on opposite sides of the conveyor belt. One of the antennas is a transmitting antenna which transmits a beam of microwaves through the test material to a receiving antenna to test a property of the material, such as its moisture content, by determining the amount of microwave beam attenuation due to microwave energy absorption by such moisture or the other property tested.
In the preferred embodiment of this invention, a single antenna 11 shown in FIG. 1 is used to direct both microwave beams of different frequency through the test material to be measured and a second similar antenna is used to receive both beams. As shown in FIG. 1, the antenna 11 consists of a thin walled conical section 12 and short cylindrical section 13 made of metal or other electrically conductive material and containing a dielectric material. The cylindrical section is closed at one end by a metallic base 14. The higher frequency microwave signal, f 1 , is fed in through a first coaxial connector 15 with its outer conductor 16 joined electrically to the cylindrical section 13 by soldering at joint 17 and with its center conductor 18 continuing to the center line or longitudinal axis of the antenna, as shown in FIG. 1A. The diameter D of the short cylindrical section 13 is related to the microwave frequency by the requirement that it be greater than the "cut off" diameter D c for that frequency given by: ##EQU1##
Where C is the velocity of light in vacuum, f 1 is the frequency of the microwave signal and ε 1 is the real part of the dielectric constant of the material filling the cylindrical section. The point at which the coaxial conductor 15 is located along the length of cylindrical section 13 is such that the distance 19 to the closed end of the cylinder is a quarter wavelength, λ G / 4 where λ G is the wavelength of the microwave of frequency f 1 inside the cylinder which is given by the formula: ##EQU2## where ##EQU3## These two equations can be combined to give: ##EQU4## From which the requirement that D be greater than D c is apparent.
The lower frequency f 2 of the two microwave frequencies is fed into the antenna 11 through a second coaxial connector 20 including an outer conductor 22 joined in the same way as coaxial conductor 15 and with its center conductor 21 similarly extending inward to the center line of the antenna. The point at which the coaxial connector 20 is located along the length of the antenna is required to meet the following conditions. There is a point along the conical section, indicated by the dashed line 23 at which the diameter of the cone is equal to the "cut off" diameter D c ' for the lower frequency f 2 given by: ##EQU5##
This means that microwaves of frequency f 2 cannot be transmitted without loss along the small diameter part of the cone. Thus, the cone portion at position 23 acts in effect like an electrical open circuit. The coaxial connector 20 is required to be located a distance 24 outwardly from this open circuit position 23 such that this distance 24 is a half wavelength, λ G '/ 2 where λ G ' is the wavelength of the microwave frequency f 2 inside the cone. This wavelength λ G ', varies along the distance 24 as the cone diameter varies. Integration over this distance gives the value L for the distance 24, from the equation: ##EQU6## Where θ is the cone angle shown at 25 in FIG. 1.
The coaxial conductors 15 and 20 are spaced 90° apart around the cone circumference, as indicated in FIGS. 1 and 1A so that the plane polarized microwave beams of signal f 1 and f 2 have their respective planes of polarization at right angles. In this way the receiving antenna, which is identical to the transmitting antenna shown in FIG. 1 can be oriented so that the higher frequency f 1 is received only by its coaxial conductor 15 and the lower frequency f 2 is received only by its coaxial conductor 20. In this way, the two signals are kept distinct and separate and do not interfere with each other.
The antennas may be filled with air as the dielectric so that ε 1 is approximately equal to 1, but in applications where they are transmitting directly into and receiving directly from a test material of higher dielectric constant, they may with advantage be filled with a dielectric of about the same dielectric constant ε 1 as that of the test material, thereby improving the antenna's radiating efficiency or enabling a smaller diameter antenna to be used. For example, to measure foundry sand using f 1 =10.7 GHz and f 2 =5.8 GHz, the present inventor has successfully used antennas 5 and 1/2 inches long with outer diameter of 3 inches and with the cylindrical section being of 3/8 inch diameter using a dielectric material to fill the antennas having a dielectric constant ε 1 of 3.8.
As already stated, the same antennas used for attenuation measurements can also provide the sensing elements for measurement of phase change to provide a more compact measurement apparatus. But, whereas, two microwave signals at the two different frequencies are used and combined to provide the attenuation measurement, only one microwave signal is used for phase measurement, and with special microwave components to separate and analyze the signal for phase. The use of a single transmitting antenna and a single receiving antenna for all three measurements is an important feature for accuracy because it ensures that all three measurements are made at the same location at the same instant of time. Furthermore, for foundry sand moisture measurement, there are many foundries where it would be physically impossible to install separate gauges close to each other.
FIG. 2 is a block schematic diagram which shows the microwave devices and other electronic components in the preferred embodiment of the microwave measurement apparatus of the invention, which are used to generate output signals Vo and Vo' proportional to attenuation of the microwave beam by the test material for each of the two frequencies f 1 and f 2 in accordance with the formulas:
a=K.sub.1 Wd+K.sub.2 d Equation 6
a'=K.sub.3 Wd+K.sub.2 d Equation 7
Where a, a' are the attenuations in decibels for the two frequencies f 1 and f 2 , and where K 1 , K 2 , K 3 are constants, W is percent water and d is density of the test material. In FIG. 2, a microwave source 30 generates an amplitude modulated microwave signal of a high frequency f 1 of, for example 10.7 GHz which passes through the directional coupler 31 and isolator 32 to connector 15 of a transmitting antenna 33 which is like antenna 11 in FIG. 1. The directional coupler 31 feeds a small part, generally between 0.1 percent and 1.0 percent of the signal f 1 to a reference detector 34 which produces a reference signal whose amplitude is proportional to the microwave power passed to the transmitting antenna.
The received microwave signal after passing through the moist test material 1 is passed from the connector 15 of a receiving antenna 35 through another isolator 37 to the input of a PIN diode variable attenuator 38 which further attenuates the signal to produce a constant signal level at the input to the signal detector 39 connected to the output of such attenuator. This constance is achieved by comparing the attenuated received signal from the signal detector 39 after it is amplified by preamplifier 36 to a fixed fraction of the reference signal from the reference detector 34 which are applied to the inputs of a high gain differential amplifier 40 to produce an attenuated output signal, Vo, proportional to the attenuation of the test material as given in Equation 6. The output signal, Vo, of differential amplifier 40 is also applied at control terminal 41 of the attenuator 38, making a closed loop, negative feedback arrangement. As a result of such negative feedback, any difference between the two compared signals at the inputs of amplifier 40 causes a change in attenuation of the received signal by the PIN diode attenuator as needed to bring the microwave signal level at the input of signal detector 39 to the desired constant value. The same circuit operation occurs when the second microwave signal of low frequency f 2 of, for example, 5.86 GHz is transmitted from source 30' through coupler 31' and isolator 32' to the coaxial connector 20 of transmission antenna 33. Therefore, such operation of the second attenuation circuit including isolator 37', variable attenuator 38', signal detector 39', preamplifier 36', reference detector 34' and differential amplifier 40' to produce the second attenuated output signal Vo' will not be described.
Clearly, if there is an increase of attenuation by the moist test material 1 there will be an equal decrease of attenuation by the PIN diode attenuators 38 and 38'. Since the attenuation by the PIN diode attenuator is a direct function of the output signal Vo and Vo' fed to its control input 41 and 41', these output signals provide a direct measure of the attenuations "a" in the moist material at frequencies f 2 and f 1 , respectively. Thus, the difference between attenuation a and attenuation a' obtained by substracting Vo' from Vo is proportional to the amount of moisture in the test material.
For phase measurement using microwave signal f 1 to determine the density of the test material, all the components of the corresponding circuit of FIG. 2 are used as described above for attenuation measurement except only that an additional directional coupler 50 is added between the microwave source 30 and directional coupler 31 to provide a phase reference signal and a hybrid divider 54 is added between the PIN diode attenuator 38 and the signal detector 39. These two added components are fixed passive devices so that their addition leaves the operation of the attnuation loop effectively unchanged.
FIG. 3 is a schematic block diagram of the phase measuring circuit used in one embodiment of the invention. Microwave source 30 transmits microwave signal f 1 through the added directional coupler 50 which feeds a small fraction (between 0.1 percent and 1.0 percent) of the signal through a level set attenuator 51 and a fixed attenuator 52 to one input of a hybrid combiner 53 to provide a phase reference signal to this combiner. On the receiving side, the output of PIN diode variable attenuator 38 is connected to the input of added hybrid divider 54 which feeds half the received signal to the attenuation loop 39, 36, 40, 41 of FIG. 2 and the other half of such received signal through a voltage variable phase shifter 55 whose output is connected to the other input of the combiner 53.
The voltage variable phase shifter 55 is arranged to be swept periodically through a full 360° phase change by the ramp shaped voltage applied to control terminal 71 by a ramp generator 56. As a result, the phase of the phase shifted received signal applied by shifter 55 to the second input to the hybrid combiner is swept periodically through 360°.
The hybrid combiner 53 combines the two input signals so that its combined output signal is the vector sum of such two input signals. If, therefore, the two input signals are of equal amplitude there will be one point in the 360° sweep where the two signals are 180° out of phase with each other and the hybrid combiner output will dip to a minimum amplitude. The operation of the attenuator loop of attenuator 38 ensures that the signal level at the output of the attenuator remains constant and is a constant fraction of the phase reference output signal of the directional coupler 50. The level set attenuator 51 is therefore adjusted to make the amplitudes of the two input signals of the hybrid combiner 53 equal. The output from the hybrid combiner 53 passes through the phase signal detector 57 which gives a detected output signal whose amplitude is proportional to the amplitude of the combined output signal of the hybrid combiner and which therefore goes through a sharp minimum at one point in each 360° sweep of the ramp generator. It should be noted that each sweep can be less than 360° if it includes the sharp minimum. This detected signal is amplified by amplifier 58, rectified by a full wave rectifier 59 and filtered by filter 60 to give a phase shift indication signal 67 at test point No. 1 as shown graphically in FIG. 4. The low pass filter 60 between the rectifier 59 and TP1 serves to clean up this signal by removing noise and unwanted components from the signal.
A differentiation circuit 61 converts the signal from TP1 to the differentiated phase shift indication signal 68 of the waveform indicated in FIG. 5 at TP2 in which there is a sharp transition through zero. The comparator 62 and capacitor 63 serves to convert this signal into a sharp positive spike pulse 69 at TP3 corresponding to the zero crossing of signal 68 and applies such spike pulse to one input of the latch 64 and as shown in FIG. 6. The other input to the latch 64 is a second sharp spike pulse corresponding to the start of the ramp voltage signal 71 which comes from the ramp generator circuit 56 so that a positive rectangular latch output pulse 70 produced at TP4 is initiated at the start of each ramp and is terminated by spike pulse 69 at the phase signal minimum point as shown in FIG. 7. This is repeated for each repetitive 360° sweep of the ramp generator and so produces a pulse train with pulses 70 of constant amplitudes and variable pulse widths with their pulse width proportional to the phase shift of the minimum point in signal 67 corresponding to the output from the hybrid combiner 53. The integrator 65 which integrates this pulse train therefore gives a phase shift output signal, Vp, whose voltage level is proportional to this phase shift.
The phase shift signal Vp is approximately proportional to the density of the test material in the following equation for the moisture range of 0 to 4 percent moisture which applies to foundry molding sand.
log ε.sub.m =C.sub.1 Wd+C.sub.2 d Equation 8
where ε m is the dielectric constant of the mixture of air, water and sand in the test material, C 1 and C 2 are constants related to the dielectric constants of water and said, W is the percent of water and d is the density of the test material.
The zero level of this phase shift output signal Vp corresponds to the phase of the received signal which would produce a hybrid combiner output signal minimum at the start of each ramp. This can be adjusted to a desired minimum corresponding, for example, to some minimum density at zero percent water by adjustment of a preset line stretcher 70 or other presetable phase shifter provided at the input of attenuator 38, as shown in FIG. 3. The phase shift output signal Vp of integrator 65 and the attenuation output signals Vo and Vo' of the differential amplifiers 40 and 40' of FIG. 2 are applied to the inputs of a data processor 66, such as an analog or digital computer, which combines such signals in accordance with Equations 6, 7 and 8 to produce a percent moisture content signal at the output of such data processor which indicates the amount of moisture in the test material 1.
It will be obvious to those having ordinary skill in the art that many changes may be made in the above described preferred embodiment of the present invention. Therefore, the scope of the present invention is to be determined by the following claims.
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A microwave measurement apparatus is disclosed for measuring an unknown property of a test material, such as moisture content, by transmitting microwave beams through such material so that a portion of the beam energy is absorbed by the moisture or other property. Two microwave input signals of different frequencies are used to form the microwave beams and the corresponding attenuated received signals are compared in order to compensate for the presence of a component in the test material, such as foundry molding sand, which is not being measured but which also absorbs microwave beam energy. To determine the density of the test material in the event of changes in such density, one of the microwave signals is used to measure the phase shift of the corresponding received signal and produce a phase shift output signal. A single microwave antenna having two microwave signal connections is employed to transmit the two microwave beams of different frequency without interference and another antenna of the same type receives such two beams to produce the two attenuated received signals. The two attenuated received signals of different frequency and the phase shift output signal are combined in a signal processor to produce a percent moisture content signal.
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This is a division of application Ser. No. 602,959, filed Aug. 7, 1975, now U.S. Pat. No. 4,065,537.
BACKGROUND OF THE INVENTION
The present invention relates to process for making molded products containing cis-polybutadiene or other elastomers, and a monomer capable of cross-linking the elastomer into a three-dimensional network. More specifically, the cross-links which are capable of being produced are relatively long and flexible. Such molding compositions are eminently suitable for the production of molded golf balls, particularly unitary molded golf balls. Molding compositions of this general class, and golf balls which can be produced from them, are described in U.S. Pat. Nos. 3,313,545, issued Apr. 11, 1967, and 3,438,933, issued Apr. 15, 1969.
There are several advantages of homogeneous, unitary construction for a golf ball, in contrast to the wound balls of the earlier art. Unitary golf balls can be produced with a perfect center of gravity and thus have excellent aero-dynamic properties, superior roll, and trueness of flight. Such golf balls are highly resistant to cutting and are often indestructible in normal play. These balls will return to round even when severely distorted, and thus maintain their superior flight characteristics after extended use.
Homogeneous, unitary golf balls, may be manufactured with better quality then conventional wound balls.
As contrasted with the conventionally covered wound balls, unitary balls maintain their playing characteristics in hot and in cold weather, have an excellent shelf-life, and will not waterlog. If the paint on the ball becomes worn or damaged, the balls may be very readily reclaimed by removing or stripping off the old paint and repainting. By contrast, conventional covered wound balls seldom last long enough to allow repainting.
Such unitary balls may be molded in mating precision hemisphere molds or dies into which a cylindrical or other shaped slug of moldable material is placed, as described in U.S. Pat. Nos. 3,313,535 and 3,438,933, the disclosures of which are incorporated herein by reference. The slugs may be cut from the extrudate of a mixer-extruder. After placing of the slug, of sufficient size to fill the mold, the mold halves are closed, and heat and pressure are provided for enough time to cure the moldable elastomer. The moldable material comprises an elastomer, a cross-linking monomer, a filler and a cross-linking catalyst. The balls after discharge from the mold are buffed, surface treated and then painted and stamped in conventional manner.
Improved unitary molded golf balls are described in application Ser. No. 250,147, filed on June 21, 1972, now pending. The improved unitary golf balls utilize a specific sub-group of cross-linking monomers and can yield molded golf balls with better rebound than prior unitary golf balls, and with superior playing qualities, equal to or surpassing the highest quality wound golf balls available, and maintaining the advantages of unitary balls. The improved unitary balls were made with decreased amounts of filler, preferably less than about 30 phr (parts per 100 parts by weight of elastomer) of filler and more preferably less than about 20 phr of filler. These low filler additions are postulated to give higher rebound and superior distance to these improved golf balls.
However, golf balls made commercially by the normal procedures described in application Ser. No. 250,147 tend to be non-uniform in compression, and roundness, and consequently are difficult to buff and stamp in the standard production equipment. As described in application Ser. No. 250,147, these golf balls do possess superior distance qualities as compared to the standard unitary golf ball, but the improved golf balls have erratic flight patterns, sometimes veering to the left, sometimes to the right, and sometimes going straight.
While such balls are quite satisfactory, and do constitute an improvement over the standard unitary golf balls with respect to distance, rebound and click, it is an object of the invention to improve further the properties of such molded balls with respect to flight pattern, uniformity of compression, roundness, durability, and the like.
SUMMARY OF PRESENT INVENTION
It has been discovered that uniform and improved golf balls of isometric properties, i.e. having a maximum difference of 10 between the compressions taken across any diameters of the ball, and having superior flight pattern, excellent roundness, uniformity of compression and durability, can be reproducibly obtained by employing specially prepared slugs in the closed mold at the onset of cure. The improved balls are made without harming the superior distance, rebound and compression of the improved golf balls.
DESCRIPTION OF THE INVENTION
The elastomer preferred in the present invention is cis-polybutadiene containing at least 20% cis configuration.
The monomer generally comprises a normally solid metal compound of a polymerizable organic moiety, and a preferred group of such monomers are the metal salts of unsaturated, polymerizable organic acids. Preferably the monomer is soluble in the elastomer base; or readily dispersible in the elastomer under the usual conditions of rubber compounding; or else the monomer is capable of being formed in situ from at least one precursor which is readily soluble in the elastomer base.
An example of in situ formation is by predispersion of a suitable basic metal compound in the cis-polybutadiene rubber, such as zinc oxide or carbonate, followed by the addition of a suitable polymerizable acid, such as acrylic or methacrylic acid. The resulting monomer, zinc diacrylate or zinc dimethacrylate, is thus formed during compounding, and is therefore present in a desirably high degree of dispersion or solution in the elastomer matrix.
Examples of suitable metals include but are not restricted to are magnesium, calcium, lithium, sodium, potassium, cadmium, lead, barium, zirconium, beryllium, copper, aluminum, tin, iron, antimony and bismuth. Polyvalent metals, i.e. those having a valence higher than 1, and especially the divalent metals zinc, magnesium, and calcium are a preferred sub-group.
Examples of metal salts of polymerizable organic acids include but are not restricted to salts of the following general formulas:
(a) carboxylates, sulfonates, and sulfinates of the formulas (RCO 2 ) m . M, R(SO 3 ) m .M, R(SO 2 ) m .M, (RCO 2 ) p . MO, (RSO 3 ) p .MO, R(SO 2 ) p .MO;
(b) phosphonates of the formulas (R 2 PO 2 ) m .M, (R 2 PO 2 ) p .MO, (RPO 3 ) q .M, (RPO 3 ).M'O;
(c) imide salts of the formulas ##STR1## (d) tin salts of the formula ##STR2## wherein each R independently is a group having at least one polymerizable olefinic unsaturation,
R' is a divalent group having a polymerizable olefinic unsaturation,
each R" independently is an alkyl, aryl or aralkyl group,
M is a metal ion having a valence, m, of from 1 to 5,
M' is a metal ion having a valence of 4,
M" is a metal ion having a valence of 1 or 2,
p is m-2 when m is greater than 2, and
q has the value m/2 when m is 2 or 4.
In (a), (b), (c), and (d), the R's may be alkenyl, aralkenyl, alkenylaryl, heterocyclic, or cycloalkenyl, and contain halogen, nitro, cyano, keto, ester, ether and or amido substituents, provided that the metal containing crosslinking monomer contains at least one polymerizable olefinic unsaturation per molecule. The alkenyl radicals, when present, preferably are lower alkenyl and the aryl radicals, when present, are preferably phenyl, each of which may be substituted as indicated.
Mixtures of different metal-containing polymerizable monomers may also be used within the scope of the present invention, provided that at least one member of the mixture be homopolymerizable. Other members of the mixture may be copolymerizable or homopolymerizable, or else only copolymerizable. An example of the second type of monomer is zinc dimaleate, which is copolymerizable with zinc dimethacrylate but not homopolymerizable.
Mixtures of different metal-containing monomers may be used to advantage for the purpose of adjusting the polymerization rate or the final density of the ball; the density of the ball is desirably below about 1.13 and preferably between about 1.11 and b 1.12, corresponding to a weight of about 1.5 to 1.62 ounces for a standard golf ball of about 1.68 to 1.685 inches in diameter. For example, zinc diacrylate when used as a sole metal-containing monomer polymerizes vary rapidly during curing, making the curing operation excessively exothermic and difficult to control. Thus, it may be advantageous to use mixtures of zinc diacrylate and zinc dimethacrylate in order to achieve a better balance of ease of processing, and final characteristics of the ball.
Examples of polymerizable salt-forming acids which are useful in the present invention are acrylic, methacrylic, 2-acetaminoacrylic, β,β-dimethacrylic, ethacrylic, α-chloroacrylic, 2-ethyl-3-propylacrylic, acotinic, β-benzoylacrylic, crotonic, aminocrotonic, allylacetic, 2-allylexypropionic, 2-furfurylacrylic, vinylacetic, allyloxyacetic, 2-vinylpropionic, vinylhydrogen phthalic, β-acryloxypropionic, 2-butene-1,4-dicarboxylic, sorbic, acetylene dicarboxylic, N-butylmaleamic, maleic, chloromaleic, di-n-butylmaleamic, N,N-dimethylmaleamic, N-ethylmaleamic, N-phenylmaleamic, dichloromaleic, dihydroxymaleic, allylarsonic, chlorandic, fumaric, itaconic, styrenesulfonic, divinylbenzenesulfonic, styrenephosphonic, and styrenesulfinic acids; maleimide, and methylmaleimide. Methacrylic, acrylic, cinnamic, acotinic, crotonic, vinylacetic, itaconic, styrenesulfonic, and benzoylacrylic acids are a preferred sub-group.
The term "metal-containing polymerizable monomers" as employed herein includes such monomers which have been at least partially prepolymerized before compounding, or after compounding or processing, and before curing. Also included are salts of carboxylic polymers such as butadiene-acrylonitrile-acrylic acid, acrylonitrile-butadiene-sorbic acid, styrene-butadiene-sorbic acid, butadiene-vinylacrylic acid, butadiene-sorbic acid, and the like, provided that these polymers contain residual polymerizable unsaturations. An advantage of using such prepolymerized cross-linking salts is that the amount of heat generated when the ball is cured is minimized, in contrast to using unpolymerized monomers. The reduced exotherm makes the molding operation more easily controlled.
The amount of the metal-containing cross-linking monomer should correspond to at least about 0.046 equivalent of polymerizable unsaturation per mole of butadiene in the elastomer base, but may be as high as 0.38 equivalent per mole. A preferred level of cross-linking monomer is about 0.08 to 0.28 equivalent per mole, while a more preferred range is about 0.10 to 0.23 equivalent per mole. Thus, if the cross-linking monomer selected is zinc dimethacrylate, the more preferred amounts are in the range of about 15 to 60 phr of zinc dimethacrylate.
Without departing from the scope of the present invention, mixtures of metal-containing and metal-free polymerizable monomers such as esters of unsaturated acids, may also be used. Examples of metal-free polymerizable monomers include but are not restricted to vinyl, allyl, methallyl, furfuryl, crotyl and cinnamyl esters of monobasic and polybasic acids such as acetic, propionic, butyric, benzoic, phenylacetic, chloroacetic, trichloroacetic, oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, maleic, itaconic, citraconic, mesaconic, fumaric, citric, acotinic, phthalic, isophthalic, terephthalic, naphthalenedicarboxylic, mellitic, pyromellitic, tumesic, acrylic, methacrylic, ethacrylic, cinnamic, crotonic, cyanuric, polyolesters and anhydrides of acrylic, methacrylic, ethacrylic, crotonic, and cinnamic acids, the said polyols including ethylene glycol, di-, tri-, and tetraethylene glycol, glycerol, 1,3-butylene glycol, 1,4-butylene glycol, trimethylolpropane, pentaerythritol, propylene glycol, di-, tri-, and tetrapropylene glycols, polyethylene glycol, and polypropylene glycol; vinyl and divinyl benzene; allyl and di-allyl benzene; mono-, di-, triallylmelamine; allyl and diallylamine; allyl ether; allyl glycolates; mono-, di-, tri-, and tetraallyl and vinyl silanes; methyl, ethyl, propyl, butyl, pentyl, hexyl, benzyl, phenyl, cyclohexyl, chloroethyl, β-cyanoethyl, dimethylaminoethyl, glycidyl, lauryl, 2-methoxy-ethyl, tetrahydrofurfuryl, hydroxyethyl and hydroxypropyl esters of acrylic, methacrylic, ethacrylic, cinnamic, crotonic, cyanuric, fumaric, maleic, and methylmaleic acids; triallyl phosphate and phosphite. Further examples include low molecular weight reactive polymers such as polymers of butadiene, isoprene, chloroprene, and epoxidized derivatives of these materials.
A preferred group of metal-free polymerizable monomers are diacrylates and dimethacrylates of ethylene glycol, propylene glycol and butylene glycol, di-, and triacrylates and methacrylates of trimethylolpropane, and di-, tri- and tetraacrylates and methacrylates of pentaerythritol. In general, metal-free monomers containing more than one polymerizable unsaturation per molecule are preferred, but monoacrylates and monomethacrylates of polyols such as ethylene glycol are also highly suitable.
To vary the density so that the finished ball will have the desired weight and will not exceed the maximum allowable weight, filler may be required. However, because the metal-containing monomer will contribute a higher density to the stock than other types of monomers such as esters of unsaturated acids, the amount of filler required to adjust the density will usually and advantageously be relatively low. The metal-containing monomer may be considered to function as a reactive filler as well as a polymerizable cross-linking agent. In some cases, adjustment of the amount of metal-containing monomer is all that is necessary to obtain the correct ball density, so that no additional filler is required.
If an inert filler is desired, any known or conventional filler may be used which should be in finely divided form, as for example, in a form less than about 20 mesh, and preferably less than about 60 mesh U.S. Standard screen size. Suitable fillers are silica and silicates, zinc oxide, carbon black, cork, titania, cotton flock, cellulose flock, leather fiber, plastic fiber, plastic flour, leather flour, fibrous fillers such as asbestos, glass and synthetic fibers, metal oxide and carbonates, and talc. Particularly useful is the oxide or carbonate of the same metal which is present in the metal-containing monomer. Impact modifiers such as ultra-high molecular weight polyethylene and acrylonitrile-butadiene-styrene resin can also be used. Reinforcing silicas can be used in combination with silanes to improve rebound of golf balls using silica alone as the filler or in combination with zinc oxide or other fillers.
The amount of inert filler is dictated mainly by its type and is preferably less than about 30 phr, i.e. of cis-polybutadiene elastomer base, and more preferably about 10 to 20 phr.
Advantageously, there is used a polymerization initiator which decomposes to produce free radicals during the cure cycle. The polymerization initiator need only be present in the catalytic amount required for this function and may be in general used in the amounts that the particular agent is generally used as a polymerization catalyst. Suitable initiators include peroxides, persulfates, azo compounds, hydrazines, amine oxides, ionizing radiation, and the like. Peroxides such as dicumyl peroxide, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, di-t-butyl peroxide, and 2,5-bis(t-butylperoxy)-2,5-dimethylhexane are commercially available and conveniently used, usually in amounts of about 0.2-10% by weight of the elastomer.
An antioxidant may be added to the compound to minimize oxidation during processing and to prevent deterioration of the golf ball during storage. The antioxidant also prevents incipient polymerization and premature reaction during molding and prevents excessive temperature build up during molding of the golf ball. However, large amounts of antioxidant retard cure and can result in low compression golf balls. Most useful quantities of polymer antioxidants are about 0.03 to 4 phr, preferred quantities are about 0.1 to 2 phr, and most preferred are about 0.15 to 1.5 phr. Representative antioxidants are alkylidene bis, tris and polyphenols, and alkylated phenols and bisphenols. Other suitable antioxidants are disclosed in U.S. Pat. No. 3,886,683 issued June 3, 1975, the disclosure of which is incorporated herein by reference.
The method of adding the metal oxide, the maximum temperature during preparation of the compound, method of extruding, temperature of compound prior to shaping slug and molding temperature affect the quality of the golf ball with respect to uniformity, roundness, flight pattern, durability, click, and compression.
For the production of golf balls, the ingredients may initially be mixed intimately using, for example, rubber mixing rolls or Banbury mixer, until the composition is uniform. In order to promote good dispersion, the metal-containing monomer may advantageously be formed in situ, for example from the metal oxide and the corresponding acid. The preferred method of preparation is the addition of the monomer over a period of about 1 to 20 minutes to from about 1/4 to 3/4 of the rubber-metal oxide mixture using from about 10% less than the equivalent amount to about a 100% excess equivalent amount of metal oxide, based on the amount needed to react with all the carboxyl groups, preferably about 80% excess and more preferably about 50% excess of metal oxide, mixing thoroughly and adding the remainder of the rubber-metal oxide mixture. The peroxide is added later. The mixing is desirably conducted in such a manner that the compound does not reach incipient polymerization temperatures.
Another preferred method is the addition of the unsaturated acid over a short period of time, e.g., about 0.2 to 6 minutes, to a mixture of the elastomer and metal oxide, mixing the ingredients, adding cross-linking catalyst, mixing further and dumping the batch.
The molded masses so far described are unitary golf balls, i.e. one-piece balls. With minor modifications, however, they can form the centers of two- or more piece golf balls including an outer cover, preferably of ionic copolymer. Such covers are known in the art and generally range in thickness from about 0.1 to 0.2 inch. The centers in such event will be somewhat higher in density to bring the overall density to the proper level. Thus, the quantity of filler is usually higher, e.g. about 20 to 40 phr and even as high as 50 phr.
In investigating prior golf balls and their production it was found that the history and contour of the slugs to molding had a pronounced effect on the properties of the golf balls molded therefrom. Thus, for example, extrusion of a cylindrical mass of about the diameter of the golf balls to be molded and cutting it into slugs produced lines of orientation in the slugs which were retained even after molding, notwithstanding the heat of molding which would have been expected to effect disorientation. Moreover, this effect was markedly more pronounced with masses including metal-containing monomers as in application Ser. No. 250,147, referred to hereinabove; apparently the fixed metal ions have a special orienting effect. At any rate, compression of golf balls measured parallel to the original orientation varied considerably from compression measured along diameters at right angles thereto and such latter compressions varied considerably from one another, often by as much as 20 units or more. These variations manifest themselves as variations in performance of the golf balls relative to one another as well as internally, i.e. the ball may veer to the left somewhat once but may veer to the right on the next drive.
In molding the balls the slugs can stand up in the mold or can be laid on their sides but, however, positioned, the spherical mold will produce an equator where the mold halves meet, which equator will be visible even after buffing of the balls, and this equator will define a pair of poles. Measurements of compression across the poles and across any two equatorial diameters at right angles to one another is a quick and fairly reliable way of ascertaining the variability within a given ball.
In accordance with the invention it was found that such variability could be minimized within each ball and from ball to ball by eliminating the effect of orientation insofar as possible. This can be done by utilizing a slug-forming technique which avoids orientation or by combining masses of material into slugs in such fashion that upon molding the individual orientations balance off against one another so the resulting ball is isometric, i.e. compression wherever measured is substantially the same. This isometricity can be achieved, for example, by employing relatively long, narrow slugs which, upon closing of the mold halves, will buckle like a column in filling the mold so that the original longitudinal lines of orientation will be arcuate or circular. Alternately, slugs made up of three or more sub-slugs (or even two, with special histories) and combined in particular spatial arrangements produce isometric balls. Use of rubber sheeting rolls rather than extruders, as well as higher temperatures, will tend to minimize the amount of orientation imparted and thus the amount of orientation to be overcome.
There follow details about several techniques in slug formation which will contribute to isometricity but they are merely illustrative and others may readily suggest themselves once the problem is in mind.
For example, the slug should not be wider than about 1.7 inches since that is the dimension of the mold cup and preferably should be in the range of about 0.7 to 1.5 inches. Although golf balls can be made using slugs having a diameter greater than about 1.7 inches, considerable waste of material results. The slug height should not exceed about 3.5 inches, since the slugs tend to topple in the mold cup causing loss of material and incomplete golf balls. Preferably heights for slug shapes are about 1.5 to 3.3 inches. A more preferred height for slugs which are to buckle is about 2.5 to 3.3 inches, approximately circular cylindrical slugs performing better at the greater lengths while cylinders with indentations, e.g. Maltese-cross or the like, performing satisfactorily even at the shorter lengths. Another consideration is the top and bottom shape of the slug. The most preferred shape is convex so that air is not trapped in the mold, leading to brown spots and/or incompletely molded areas on the surface of the golf ball. Approximately cylindrical slugs having essentially flat or convex top and bottom surfaces produce essentially brown-spot-free golf balls.
With these considerations in view, techniques to prepare slugs having shapes necessary to provide uniform golf balls will be described.
The mixture may be sheeted on a roll mill and the sheet rolled into a cylinder about 2.5 inches in diameter. The roll is cut into suitable slugs having multi-lines of orientation.
Another technique is to mill the stock on a warm mill, preferably about 40° to 60° C., and feed the warmed stock to a Barwell extruder--a ram type extruder. The stock is extruded through a Maltese cross or clover shaped die to give shapes which upon pressing in the mold give multi-oriented shapes.
Another technique is to sheet the stock on a mill, strip off 4-inch wide strips and feed the strips to a rubber-type extruder. The stock is extruded through a die to form a strand of approximately hemispherical cross-section. After cooling to room temperature, two strands are pressed together along their flat sides and cut into half-length slugs by a slug cutter. One half-length slug is separated and the components placed on top and bottom of a non-separated half-length slug to give a capped slug. Alternately, the slug can be molded as is to give a multi-oriented shape upon press closure.
Other shaped dies can be used to obtain the desired effect from extruded stock. Alternatively, sheets of stock can be cross-laminated to give a multi-oriented effect and suitably shaped slugs can be stamped out from the sheet, like shoe soles, to give suitably shaped slugs.
The molding is effected in mating, precision hemisphere molds or dies whose molding surface is covered with multiple regular projections to give the molded ball conventional dimpled or waffled surface appearance in order to improve its aero-dynamic characteristics. The molding is a simple, straight-forward operation effected in the conventional manner used in precision molding. The material, after being thoroughly mixed, is formed into suitably shaped slugs, as described herein, which will facilitate insertion in the mold, and proportioned so that the mold is fully filled. The mating halves of the mold are then closed so that the mold cavity is entirely filled. The mold halves may be held together with pressures between about 100 and 150,000 psi, preferably about 5,000 to 10,000 psi.
Molding temperature may vary depending on the particular composition used and may, for example, range between about 130° and 200° C. Curing times may range from about 1 to 50 minutes, and preferably about 5 to 30 minutes.
It is preferred to optimize the curing time and temperature in order to obtain the best properties of the golf ball. The best curing conditions are dependent upon the particular formulation selected. Because of the highly exothermic nature of the curing process, the properties of the present golf balls are highly sensitive to curing conditions, in contrast to the prior art balls made using only metal-free monomers.
After molding, the balls are removed from the mold and any mold marks buffed off, and the ball is painted and marked, and is then ready for use. Painting may be effected in the conventional manner using the conventional paints used for golf balls, as for example, enamel, polyurethane, epoxy, acrylic, or vinyl paints.
The resultant isometric golf balls have maximum differences of 10 compression units or less, often 5 units or less, when compression readings are taken at two or more places on the surface of the golf ball, typical places being the pole and two spots on the equator, although any other spots on the surface of the ball can be selected. The golf balls can have compression values from about 40 to 130, preferably about 50 to 120 and more preferably about 60 to 110.
The term "Compression" in the golf ball industry relates to an arbitrary value expressed by a number which can range from 0 to over 100, and that defines the deflection that a golf ball undergoes when subjected to a compressive loading. The specific test is made in an apparatus fashioned in the form of a small press with an upper and a lower anvil. The upper anvil is at rest against a 200-pound die spring, and the lower anvil is movable through 0.300 inches by means of a crank mechanism. In its open position the gap between the anvils is 1.780 inches allowing a clearance of 0.100 inches for insertion of the ball. As the lower anvil is raised by the crank, it compresses the ball against the upper anvil, such compression occurring during the last 0.200 inches of stroke of the lower anvil, the ball then loading the upper anvil which in turn loads the spring. The equilibrium point of the upper anvil is measured by a dial micrometer if the anvil is deflected by the ball more than 0.100 inches (less deflection is simply regarded as zero compression) and the reading on the micrometer dial is referred to as the compression of the ball. In practice, tournament quality balls have compression ratings around 90 or 100 which means that the upper anvil was deflected a total of 0.190 or 0.200 inches.
Another property which is measured in the following examples and/or in assessing performance of golf balls is the cannon life. The cannon life test is a measure of the durability of a golf ball under severe impact conditions. In this test, a box is constructed of 1/4-inch thick steel plate in the shape of a rectangular prism with edges 2 ft. by 2 ft. by 3 ft. One end of a steel tube 1.687 inches in internal diameter by 5 ft. long is sealed to one 2 ft. by 3 ft. face of the box at a point which is one foot from a 2 ft. edge and same distance from a 3 ft. edge. The axis of the tube is inclined 45° to a line parallel to the 2 ft. edge of said face, and 80° to a line parallel to the 3 ft. edge of the face. The other end of the tube is connected to a 20-gallon air tank via a fast-acting valve and contains a port for introducing a golf ball. The tube thus constitutes an air cannon.
In operation, the air tank is pressurized to 40 or 70 pounds per square inch, and the ball is shot into the box by sudden release of the air pressure. The "cannon life" is the average number of successive shots which a golf ball will withstand before rupturing or otherwise becoming unplayable. Usually about four to ten balls are tested for cannon life, and the results are averaged.
The invention will be further described in the following illustrative examples wherein all parts are by weight unless otherwise expressed.
EXAMPLE 1
To a No. 3A Banbury were added 72 pounds of 98% cis-polybutadiene, 27 pounds of 2/1 zinc oxide/cispolybutadiene and 100 grams of antioxidant 2,2'-methylene bis(4-methyl-6-tertiary butyl phenol). The 98% cispolybutadiene is Taktene 1203 made by Polysar Limited. The antioxidant is made by American Cyanamid Co. under the trade name of AO 2246. The ingredients were blended and 19 points of glacial methacrylic acid were added rapidly to the mixture and blended with the mixture. The masterbatch was sheeted on a plant mill (16×42"). The stock was returned to the Banbury and five pounds of Di-Cup 40C was mixed with the compound. The blend was dumped, sheeted and extruded through an oval shaped die to give slugs with a width across the cut face of 15/8-inch, across the exposed side of 11/8-inch and a height of 21/8-inch. A typical slug gave compression at the pole of 107 and at the equator minimum compression value was 104 and maximum compression value was 120 for a difference at the equator of 16 points. These golf balls gave erratic flight patterns and veered to the right or left, slicing or hooking when hit by a hitting-machine, and sometimes would go straight without alteration of flight path. Compression data for other golf balls were:
______________________________________Compression, UnitsPole Equator Diff.______________________________________106 102 118 16111 95 111 16107 120 102 18107 100 118 18105 116 97 19107 104 120 16107 121 98 23107 100 120 20105 120 98 22108 114 97 17107 116 100 16106 120 108 14107 121 97 24106 120 96 24106 120 93 27105 110 97 13105 117 102 15______________________________________
EXAMPLE 2
A blend was made of 266.7 grams of 98% cispolybutadiene and 99.9 grams of a 2/1 zinc oxide/cispolybutadiene masterbatch on a laboratory mill. To the blend was added 0.816 gram Antioxidant 2246, followed by 70.5 grams of glacial methacrylic acid. The ingredients were mixed thoroughly and 18.5 grams of Di-Cup 40C was mixed into the batch. The stock was sheeted, rolled and a slug having a diameter of about 1.5×1.25-inches and a height of about 2 inches was cut from the rolled sheet. The slug was molded at the edge of the press for 30 minutes at about 156° C. A golf ball had a compression of 94 at the pole and compressions of 94 and 97 at the equator. The golf ball had excellent feel and rebound and had true and consistent flight pattern. Another golf ball had compression values of 93 at three different points on the golf ball.
EXAMPLE 3
To the No. 3A Banbury were added 75 pounds of 98% cis-polybutadiene and 14 pounds of 2/1 zinc oxide/cis-polybutadiene masterbatch containing 2,2'-methylene bis(4-methyl-6-tertiary butyl phenol). The ingredients were mixed thoroughly and 19.8 pounds of glacial methacrylic acid were pumped into the Banbury over a period of 7.5 minutes . The ingredients were mixed and 14 pounds of the 2/1 zinc oxide/cis-polybutadiene blend was added. The ingredients were blended, dumped, sheeted on a mill and returned to the Banbury where 5.25 pounds of Di-Cup 40C was blended into the batch. Stock was extruded through an oval die and slugs were cut across the cut face of the slug. One piece was rotated 90° and placed over the other piece. The final slug was about 21/4-inches high and about 11/4-inch×13/8-inches in area. Slightly less than half (about 7/8-inch) of each of the four faces of the slug consisted of a cut surface and slightly more than half (about 13/8-inch) consisted of a skin surface. Slugs were molded at 155° C. Compression values were:
______________________________________Compression DifferencePole Equator Pole-Eq. Eq.-Eq.______________________________________99 112 108 13 497 108 100 11 8100 112 98 12 14______________________________________
Another batch of golf balls was molded from a different production batch using the same slug preparation. Compression values for individual golf balls were:
______________________________________Compression DifferencePole Equator Pole-Eq. Eq.-Eq.______________________________________85 96 97 12 193 105 97 12 899 107 100 8 796 108 98 7 595 112 94 17 895 107 95 12 1295 106 104 11 293 110 106 17 495 107 101 12 695 111 106 16 597 108 98 11 1090 106 96 16 1090 106 98 16 870 88 80 18 8______________________________________
Although there was a distinct improvement in the compression difference between the pole and the equator as compared to Example 1, the compression difference between the pole and the equator was high.
Stock from the first production batch was milled into 1/4-inch thick sheets. Two sheets were cross-laminated, and 50-gram slugs were prepared about 1.5-inches wide, 0.5-inch deep and about 3.5-inches long. The slugs were molded at 155° C. Compression values were:
______________________________________Compression DifferencePole Equator Pole-Eq. Eq.-Eq.______________________________________104 108 101 4 7100 112 106 12 6109 112 97 12 15101 110 98 9 12 98 110 102 12 8102 112 103 10 9______________________________________
Although the overall compression uniformity was improved compared to Example 1, the uniformity was not isometric, indicating more laminates are needed to eliminate the effect of orientation.
EXAMPLE 4
Compound made in the Banbury was extruded through a split half-moon die and cut into two-piece 50-gram slugs. Each half slug was 1.5 inches long, 1.5 inches wide at the flat inside and 12/16 inch deep. The two flat inside sections of the slug were sliced, to remove the skin, the two sections were pushed together and the skins were placed on the top and bottom halves so that no cut surfaces were exposed. The slugs were molded at 155° C. for 30 minutes to give four golf balls with these compressions:
______________________________________At Pole At Equator Max. Diff.______________________________________96 94 89 794 96 90 688 88 78 10______________________________________
Compound made in the Banbury was extruded through the split half-moon die, cut into 50-gram slugs as described above, the outside surfaces (skin) near the top and bottom were stretched and the two sections were pushed together to minimize the exposed amount of cut surface. Typical compression values for the golf balls were:
______________________________________Pole Equator Max. Diff.______________________________________99 96 92 7102 97 90 1296 96 90 6100 96 90 10101 97 90 1197 95 87 1098 98 89 9100 95 89 1199 98 94 5______________________________________
Three golf balls had differences of 13 to 15.
The differences of 11-15 were attributed to the memory of the batch, causing the slug to return to its original shape and exposing the cut and oriented surface.
EXAMPLE 5
To a #A Banbury were added 71.25 pounds of 98% cis-polybutadiene and 14.6 pounds of 2/1 zinc oxide/cis-polybutadiene masterbatch. The ingredients were mixed and 17.1 pounds of glacial methacrylic acid were pumped into the Banbury. After the addition was completed, the batch was mixed and 12.0 pounds of 2/1 zinc oxide/cis-polybutadiene was dumped into the Banbury. The batch was mixed, dumped and sheeted on a plant 2-roll mill. The sheets were allowed to cool to room temperature.
The sheets were returned to the Banbury and 4.75 pounds of Di-Cup 40C were added. The ingredients were mixed, dumped and the compound sheeted on a plant mill.
Sheeted stock was mixed on a mill at a stock temperature of 34° C. and extruded in a Barwell machine through a three-sided star (tri-clover shaped) die - 3-inch die 7/8-inch aperture, 1/8-inch land and 45° lead using a barrel temperature of 34° C. to give a very irregular slug - through a 3-inch die with 15/16-inch aperture, 1/8-inch land, 45° lead with four-sided star design (Maltese cross shaped) to give 15/8-inch diameter and 11/4-inch long slug, and through a 3-inch die with a diamond-shaped aperture to give a very irregular shaped slug that was not readily moldable. Seven golf balls made at 155° C. using the clover shaped die had an average compression of 90, a pole-equator compression difference of 6.3 and a cannon life of 7, whereas 11 golf balls made at 155° C. using the Maltese cross shaped die had an average compression of 97, a pole-equator compression difference of 12 and a cannon life of 3.
The compressions for the seven golf balls using the clover shaped die were:
______________________________________Pole Equator Diff.______________________________________91 90 82 991 95 91 485 96 92 1195 93 87 888 92 89 490 92 90 288 94 90 6______________________________________
The compression for the 11 golf balls using the Maltese cross shaped die were:
______________________________________Pole Equator Diff.______________________________________102 94 93 991 91 80 1197 93 87 1091 90 80 186 87 77 1097 86 82 15100 95 88 12103 89 88 1598 88 81 17104 92 86 1896 88 81 15______________________________________
EXAMPLE 6
Compound made in Example 5 was mixed on a mill at 50° C. using a barrel temperature of 40° C. and extruded in a Barwell unit. The Barwell extruder is a hydraulically operated ram type extruder which uses vacuum to reduce the porosity of the extrudate and a constant speed cutter mounted on a flywheel to produce accurate blanks. Stock was extruded through a 3-inch die with 7/8-inch aperture, 1/8-inch land, 45° lead, and a three-sided star design with 1 3/16 inch diameter and 31/8-inch long, and gave 17 golf balls having an average compression of 88, a pole-equator difference of 5.8 and a cannon life of 12. Slug size from this die was 1 3/16-inch diameter and 31/8-inch height.
Typical compression values for the golf balls were as follows:
______________________________________Pole Equator Diff.______________________________________88 94 93 685 93 90 888 92 90 490 93 91 388 97 90 9______________________________________
Stock was extruded through a 3-inch die with 15/16-inch aperture, 1/8-inch land, 45° lead and with four-sided star design to give slug having 1 9/16-inch diameter and 2 5/16-inch height. The slugs were molded at 155° C. to give eight golf balls having an average compression of 95, a pole-equator difference of 5.2 and a cannon life of 15.
Compression values for the golf balls were as follows:
______________________________________Pole Equator Diff.______________________________________98 89 89 997 91 88 988 88 85 397 95 92 595 97 97 293 92 90 3______________________________________
Stock was extruded through a 3-inch die with a 15/16-inch aperture, 1/8-inch land, 45° lead to give cylinder shaped slugs having a 11/2-inch diameter and 2-inch height. The slugs were molded for 30 minutes at 155° C. to give 21 golf balls having an average compression of 99, a pole-eqator difference of 12.9 and a cannon life of 14. The golf balls had a brown spot on one pole, indicating air was entrapped in the mold.
Typical compression values for the golf balls were:
______________________________________ Pole Equator Diff.______________________________________103 88 87 1698 86 85 1393 84 86 9102 85 86 17101 88 88 1391 84 86 799 84 83 16______________________________________
In this series, golf balls having uniform compression properties and acceptable cannon life were made using clover and Maltese cross shaped slugs that were prepared by warming the stock to 50° C. prior to Barwell extrusion. Essentially little orientation existed in the stock after milling at 50° C. and the warm stock was not oriented by Barwell extrusion. Milling the stock at room temperature and extruding the relatively cold stock in the Barwell produced non-uniform golf balls.
EXAMPLE 7
To a #3A Banbury were added 71.25 pounds of 98% cis-polybutadiene, 14.6 pounds of 2/1 zinc oxide/cis-polybutadiene. The ingredients were mixed thoroughly and 17.1 pounds of glacial methacrylic acid were pumped slowly into the Banbury. The ingredients were mixed and 12.0 pounds of 2/1 zinc oxide/cis-polybutadiene blend was added. The ingredients were blended, dumped, sheeted on a mill, and returned to the Banbury where 4.75 pounds of Di-Cup 40C was blended into the batch. Stock was extruded through a split-die (half-moon) 11/8-inch long by 1/2-inch at the center of the half-moon. The extrudates were allowed to cool to room temperature. Then two strings were pressed together and 50-gram slugs were cut. The slugs were about 17/8-inches high, 1.5-inches wide. Typical compressions of golf balls from two production runs were as follows:
______________________________________Production Run 1 Diff.Pole Equator P-E E-E______________________________________100 83 83 17 099 88 83 16 5100 85 83 17 296 84 83 13 197 86 86 11 098 85 85 13 0101 86 84 17 298 82 81 17 196 82 81 15 1102 85 84 18 1100 83 80 20 3100 82 82 18 0______________________________________Production Run 2 Diff.Pole Equator P-E E-E______________________________________100 85 84 16 199 86 86 13 097 84 83 14 197 86 85 12 1102 88 87 15 199 85 84 15 1101 88 86 15 295 85 81 14 499 82 82 17 0103 88 88 15 095 85 85 10 096 86 85 11 1______________________________________
EXAMPLE 8
To a #3A Banbury were added 70 pound of 98% cis-polybutadiene, 14.3 pounds of 2/1 zinc oxide/cis-polybutadiene. The ingredients were mixed thoroughly and 17.3 pounds of glacial methacrylic acid were pumped slowly into the Banbury. The ingredients were mixed and 11.8 pounds of 2/1 zinc oxide/cis-polybutadiene was added. The ingredients were blended, dumped, sheeted on a mill, and returned to the Banbury where 3.5 pounds of Di-Cup 40C was blended into the batch. Stock was extruded through a split-die (half-moon shape) described in Example 7 to give 25-gram slugs about 11/4-inch long and about 11/4-inch wide across and about 11/8-inch wide along the flat side.
The extrudates were allowed to cool to room temperature. Two strings were pressed together and 25-gram slugs were cut. Every other pair of cut slugs was separated and the two halves were placed over the top and bottom half of a non-separated pair so that the uncut surfaces rested on the cut surfaces of the non-separated pair and so that the cut surfaces of the separated pair were horizontal and constituted the only exposed cut surfaces. Also, the round surfaces of the half moon nestled into the round surfaces of the cup molds. The slug was about 2.5-inches high and 11/8×13/8-inch in area . The slug was molded for 30 minutes at about 155° C.
Typical compression values for individual golf balls were:
______________________________________No. 1Compression DiameterPole Equator Diff. Pole Equator Diff.______________________________________94 98 4 1.683 1.685 895 97 2 1.682 1.680 299 101 2 1.671 1.674 395 101 6 1.678 1.685 789 89 0 1.675 1.673 298 100 2 1.682 1.678 497 99 2 1.678 1.684 697 103 6 1.678 1.674 491 100 9 1.674 1.678 492 95 3 1.675 1.676 188 91 3 1.672 1.678 6101 102 1 1.671 1.678 793 98 5 1.677 1.676 196 104 8 1.677 1.682 5______________________________________No. 286 94 92 896 95 94 297 89 88 991 98 91 792 95 90 592 96 86 1093 97 87 1097 99 89 1090 94 93 493 97 89 8______________________________________
EXAMPLE 9
To a #3A Banbury were added 70 pounds of 98% cis-polybutadiene, 14.3 pounds of 2/1 zinc oxide/cis-polybutadiene. The ingredients were mixed and 18.1 pounds of glacial methacrylic acid were added slowly and 14.3 pounds of 2/1 zinc oxide/cis-polybutadiene was added. The ingredients were blended, dumped, sheeted on a mill, and returned to the Banbury where 3.5 pounds of Di-Cup 40C was blended into the batch. Stock was extruded through a 1-inch dented circle die, the dents having 1/4-inch sides and using a piano wire across the face of the die to give two extrudate strings. The extrudates were allowed to cool to room temperature and fed to a slug-cutter to obtain slugs about 23/4-inches long and about 11/4-inches wide. The slugs were molded into golf balls. The golf balls had a cannon life of 16, 17 and 17 for three individual balls. Typical compression and roundness data for the golf balls were:
______________________________________Compression DiameterPole Equator Diff. Pole Equator Diff.______________________________________97 92 5 1.690 1.685 588 94 6 1.685 1.688 390 89 1 1.685 1.678 797 92 5 1.690 1.685 588 94 6 1.685 1.688 390 89 1 1.685 1.678 783 93 10 1.675 1.678 386 93 7 1.680 1.680 083 88 5 1.675 1.673 278 88 10 1.674 1.676 2______________________________________
EXAMPLE 10
To a #3A Banbury were added 26 pounds of a 130/65/0.88 zinc oxide/cis-polybutadiene/2.2'-methylene bis (4-methyl-6-tertiary butyl phenol) masterbatch and 70 pounds of cis-polybutadiene. The ingredients were mixed for one minute and 18.3 pounds of glacial methacrylic acid were added over a four-minute period. The ingredients were mixed for eight minutes and 3.5 pounds of Di-Cup 40C were added. The ingredients were mixed for several minutes, dumped, sheeted on a plant mill and extruded through a split die. The extrudate was cut into slugs which were molded 30 minute at 155° C. Each slug consisted of four sections, 11/8-inch long, 3/4-inch deep across the half-moon section and 11/4-inch wide along the half-moon section. Two pieces were placed together along the flat sides and one piece was placed flatside down on the top side and the other was placed flatside up on the bottomside. The slugs were preweighed to 48.5 and 49.0 grams. Compression values for individual golf balls were:
______________________________________Compression DifferencePole Equator Pole-Eq. Eq-Eq______________________________________48.5-gram Slugs88 90 85 3 593 98 89 5 987 87 85 2 288 88 85 3 382 84 80 2 482 90 88 8 281 87 84 6 392 91 90 2 190 92 90 2 292 90 89 3 185 84 80 5 483 85 83 2 285 85 83 2 290 92 91 1 194 103 95 9 8______________________________________49.0-gram Slugs87 95 93 8 292 94 93 2 193 95 90 3 594 95 86 8 991 91 92 1 193 93 91 2 296 91 90 6 187 92 90 5 2______________________________________
EXAMPLE 11
To a #3A Banbury were added 43.1 pounds of a 124/62 zinc oxide/98% cis-polybutadiene masterbatch and 65.6 pounds of 98% cis-polybutadiene. The ingredients were mixed for one minute and 15.2 pounds of glacial methacrylic acid with 108.8 grams of 2,2'-methylene bis(4-methyl-6-tertiary butyl phenol) were added over a period of four minutes. The ingredients were mixed for 15 minutes and 4 pounds of Di-Cup 40C were added. The ingredients were mixed, dumped, sheeted on a plant mill, and extruded through a split die. The strands were cut into 25-gram slugs; each slug consisted of two sections. The sections were 5/8-inch deep, 1.5-inches long along the half-moon and about 3/4-inch high at the center of the half-moon. A pair was separated and the flat part of one section was placed on top and the other on the bottom of another pair. The final slug was about 15/8 inch wide, 13/8-inch deep and 21/4-inch high. Several slugs were prepared by this method. The slugs were molded for 15 minutes at 175° C. Compression values were:
______________________________________ Polar Equatorial______________________________________ 54 52 50 51 50 47 49 44 53 55 58 55 52 54 54 51 55 53 58 60 55 48 51 48 56 60 54______________________________________
The centers can be converted into two-piece golf balls by molding ionomer copolymers onto the centers at 150° C.
EXAMPLE 12
To a #3A Banbury were added 56 pounds of 98% cis-polybutadiene, 23 pounds of silica, 10 pounds of high molecular weight polyethylene. 400 grams of titanium dioxide, 800 grams each of magnesium oxide and Di-Cup 40C and 200 grams of antioxidant 2,2'-methylene bis(4-methyl-6-tertiary butyl phenol). The ingredients were mixed for one minute and 22 pounds of trimethylol propane trimethacrylate was added. The batch was mixed for nine minutes, dumped, sheeted and extruded through the oval shaped die described in Example 1. Golf balls were molded at 175° C. using the slugs described in Example 1. Compression data were:
______________________________________ Polar Equatorial______________________________________ 92 92 92 88 88 85 85 83 83 80 82 82 92 92 90 83 83 73 85 81 81 85 88 85 84 82 78 87 88 87 78 82 73 88 84 80______________________________________
It will be appreciated that the instant specification and examples are set forth by way of illustration and not limitation, and that various modifications and changes may be made without departing from the spirit and scope of the present invention.
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A golf ball comprising a substantially spherical homogeneous molded mass of elastomer highly cross-linked into a three dimensional network with long, flexible cross-links formed from a metal-containing cross-linkable monomer, said comonomer simultaneously functioning at least in part as a filler, said mass exhibiting substantially isometric compression across any diameter. Advantageously the elastomer comprises polybutadiene and said metal-containing cross-linkable monomer comprises zinc dimethacrylate present in about 15 to 60 parts per 100 parts by weight of the polybutadiene. The composition may additionally contain a small amount of zinc oxide. By proper selection of the shape and make up of the slugs from which the balls are molded or by particular techniques, e.g. laboratory sheeting mills, balls can be produced which have a maximum difference in compression across different diameters of about 5 units.
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TECHNICAL FIELD
This disclosure relates to bearing systems.
BACKGROUND
Equipment and machinery often contain moving (e.g., rotating, translating) members, which require support during operation. A bearing, or similar device, may be used to support the moving member. Although some bearings may require direct contact with the member to provide the necessary support, some applications benefit from non-contact, or nearly non-contact, support for the member. Application of non-contact bearings may also include direct contact bearings for backup security.
SUMMARY
The present disclosure describes a mechanical backup bearing system arrangement to work in conjunction with non-contact magnetic bearings and capable of coping with thermal expansions of the bearing components during operation. Expansions or contractions of an inner or outer race of a bearing can be compensated using particular springs providing a low profile and a proper stiffness. In a general aspect, an electric machine system includes a rotational portion and a stationary portion. The electric machine further includes a magnetic bearing configured to support the rotational portion to rotate within the stationary portion. A mechanical back-up bearing resides in a cavity between the rotational portion and the stationary portion. A flat spring is carried by the stationary portion and abuts the back-up bearing.
One or more of the following features can be included with the general aspect. The back-up bearing can further include an inner backup bearing race that comes in contact with the rotational portion when the rotational portion is not supported by the magnetic bearing. An outer backup bearing race is also carried by the stationary portion. The outer race and the inner race can encase backup bearing balls. The flat spring can contact the lateral side of the outer race. The flat spring may be configured to deflect upon an axial movement of the lateral side of the outer race. The flat spring can apply a preloaded force to the outer race.
Additional features can be included with the general aspect. The electric machine system can further include a retainer that clamps the flat spring against the stationary portion. The retainer is separated from at least a portion of the flat spring by an air gap. The flat spring can be configured to deflect towards the air gap upon thermal expansion of the inner race of the back-up bearing. The retainer may be a hard stop for deflection of the flat spring upon thermal expansion of the inner race. The stationary portion of the electric machine system can further include an end housing. The flat spring can be carried by the end housing and supported against the end housing by a shim. In some implementations, the flat spring includes a flat circular disk with a central hole. The flat spring may also include a number of radial slots. In some implementations, the back-up bearing can be a duplex bearing.
DESCRIPTION OF DRAWINGS
FIG. 1 is a half cross-sectional view of an electric machine system using magnetic bearings in accordance with the present disclosure.
FIG. 2 is a detailed cross-sectional view of a backup bearing system of the electric machine system of FIG. 1 .
FIG. 3A is a detailed half cross-sectional view of a flat spring in loaded condition as implemented in FIG. 2 .
FIG. 3B is a detailed half cross-sectional view of the flat spring of FIG. 3A in pre-assembled condition.
FIG. 3C is a detailed half-cross-sectional view of the flat spring of FIG. 3A in a full-stop condition.
FIG. 4A is a perspective view of an example spring in accordance with the present disclosure.
FIG. 4B is a perspective view of another example spring in accordance with the present disclosure.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
This disclosure relates to a mechanical backup bearing arrangement to work in conjunction with a magnetic bearing system, which features a mechanism for accommodating thermal expansions or contractions of the mechanical bearing components, particularly occurring when the inner races of a backup bearing suddenly come into contact with a moving member. Thermal expansions or contractions of an inner or outer race of a bearing can be compensated by using a flat spring configuration. In an electric machine system, a magnetic bearing system can be backed up by mechanical bearings. The mechanical backup bearings are used in case the magnetic bearings are not used or cannot provide sufficient support, such as due to overloading, component malfunction, or other reasons. The mechanical backup bearing can include two angular contact ball bearings mounted face to face (e.g., two bearings in juxtaposition and opposite in the axial loading direction of each bearing). The ball bearings can include an inner race mounted concentrically with the rotor of the electric machine with a clearance sufficient that there will be no mechanical contact between the rotor and the backup bearing when the rotor is supported by a magnetic bearing. The inner races and the outer races of two ball bearings can be aligned facing each other and each bearing can be dimensioned so that there will be a small gap between the outer races when a clamping pressure is applied to their outer faces bringing the inner races together. In this configuration, clearances between the bearing balls and the inner and outer races can be effectively removed, making the assembly axially and radially very stiff. The clamping force needed to just bring the outer races into contact is referred to as the preload. If the preload is not excessively high, the balls will still maintain an ability to roll around the races. The clamping pressure in this configuration, however, can increase uncontrollably due to thermal expansion of the bearing inner races if the outer races are rigidly clamped against each other. For example, in an electric machine system (e.g., a motor or a generator) having a rotating rotor, the shaft of the rotor can have a much higher temperature than the housing, e.g., as a result of cooling condition differences and the heat generated by rotation and friction at or near the shaft, particularly when a rotating shaft comes into a mechanical contact with the inner races of a backup bearing. Heat of the shaft can be transferred to the bearing inner races, which thermal expansion can result in an increased outward pressure on the bearing balls, which, in turn, will apply more pressure on the bearing outer races. The present disclosure describes a system, method, and apparatus for maintaining adequate/appropriate/correct clamping pressure in a preloaded duplex backup bearing arrangement when the inner race temperature changes.
As described previously, an electric machine system can use magnetic bearings to support a rotor. An Active Magnetic Bearing (AMB) uses an electromagnetic actuator to apply a controlled electromagnetic force to support the moving member in a non-contact, or nearly non-contact, manner. The non-contact or nearly non-contact support provided by the magnetic bearing can allow for frictionless or nearly frictionless rotation of the rotor.
FIG. 1 is a cross-sectional view of an electric rotational machine 100 in accordance with the present disclosure. FIG. 1 shows an example of using an AMB system in an electric rotational machine 100 . The electric rotational machine 100 can be, for example, an electric motor 104 driving an impeller 106 (e.g., liquid and/or gas impeller) mounted directly on the motor shaft 108 . The electric motor 104 shown in FIG. 1 has a rotor 110 and a stator 112 . Alternatively, the impeller 106 can be driven by a flow of gas or liquid and spin the rotor 110 attached to it through the motor shaft 108 . In this case, the electric motor 104 can be used as a generator which would convert the mechanical energy of the rotor 110 into electricity. In embodiments, the rotor 110 of the electric rotational machine 100 can be supported radially and axially without mechanical contact by means of front and rear radial AMBs 114 and 116 . The front combination AMB 114 provides an axial suspension of the rotor 110 and a radial suspension of the front end of the rotor, whereas the rear radial AMB 116 provides only radial suspension of the rear end of the rotor 110 .
When the radial AMBs 114 and 116 are deactivated, the rotor rests on the mechanical backup bearings 120 and 122 . The front mechanical backup bearing 122 may provide the axial support of the rotor 110 and a radial support of the rotor front end, whereas the rear mechanical backup bearing 120 may provide radial support of the rear end of the rotor 110 . There are radial clearances between the inner diameters of the mechanical backup bearings 120 , 122 and the outer diameters of the rotor portions interfacing with those bearings to allow the rotor 110 to be positioned radially without touching the mechanical backup bearings 120 , 122 when radial AMBs 114 and 116 are activated. Similarly, there are axial clearances between the mechanical backup bearings 120 , 122 and the portions of the rotor 110 interfacing with those bearings to allow the rotor 110 to be positioned axially without touching the mechanical backup bearings 120 and 122 when radial AMBs 114 and 116 are activated.
The front mechanical backup bearing 122 is further discussed in FIG. 2 , which depicts details of the view 190 . As described above, FIG. 2 is a detailed cross-sectional view 190 of the front mechanical backup bearing 122 of the electric rotational machine system 100 of FIG. 1 . Details of the axial spring 230 are further discussed in FIGS. 3A to 3C . Briefly, and in conjunction with FIG. 2 , view 190 illustrates a front mechanical backup bearing 122 formed by two angular-contact ball bearings 242 and 244 aligned concentrically to each other and to the rotor 210 while maintaining a radial clearance 250 and axial clearances 252 and 254 between the backup bearing inner races 211 and 213 and the rotor 210 when the rotor 210 is supported by front and rear radial Active Magnetic Bearings 114 and 116 as shown in FIG. 1 . When the rotor 210 is not supported by front and rear radial Active Magnetic Bearings 114 and 116 , their displacement on this end of the machine is limited in extent since either the cylindrical landing surface 260 or axial landing surfaces 262 or 264 of the rotor 210 will come into contact with the backup bearing inner races 211 and 213 .
As it is commonly done in backup bearings for Active Magnetic Bearing systems, the angular-contact ball bearings 242 and 244 are mounted in a resilient mount cartridge 237 which is located inside of a stationary cavity formed by the machine housing 270 and a resilient mount cover 235 . The resilient mount cartridge 237 is dimensioned so that by itself it is free to move radially within the cavity, but has minimal ability to move axially. The radial movements of the resilient mount cartridge 237 are constrained by flexible elements 280 (e.g. O-rings), which also may dampen possible radial oscillations of the resilient mount cartridge 237 and angular-contact ball bearings 242 and 244 that it supports. Such arrangement may be needed to improve radial system dynamics when the rotor 210 comes in contact with the backup bearings after being supported by AMBs.
The angular-contact ball bearings 242 and 244 are dimensioned so that when a clamping pressure is applied to the outer faces 221 and 223 of their outer races 212 and 214 , their backup bearing inner races 211 and 213 come in contact, whereas a small axial gap 275 is maintained between the inner faces of the outer races 212 and 214 . Such a scheme eliminates a free play between the bearing balls 217 , 218 and the inner and outer backup bearing races 211 through 214 . It is also possible to completely close the gap 275 if a sufficient preload is applied.
As disclosed, the clamping pressure is generated by an axial spring 230 , which can be dimensioned to have a right amount of axial stiffness: large enough to maintain the outer race 214 in contact with the right hard stop 282 , but not so excessive that thermal growth of the backup bearing inner races 211 and 213 would result in excessive clamping pressure to cause the bearing balls 217 and 218 to cease rotating around the bearing races.
In case an excessive axial loading is exerted by the rotor 210 on angular-contact ball bearings 242 and 244 in the direction to deflect the axial spring 230 outboard (to the left in FIG. 2 ), a hard mechanical stop 284 can be added to limit the spring deflection and the amount of the axial travel allowable for the rotor 210 .
Front AMB 114 consists of a combination radial and axial electromagnetic actuator 101 , radial position sensors 124 , axial position sensor 126 and control electronics 150 . The combination radial and axial electromagnetic actuator 101 may be capable of exerting axial forces on the axial actuator target 109 and radial forces on the radial actuator target 111 , both rigidly mounted on the rotor 110 . The axial force is the force in the direction of Z-axis 117 and the radial forces are forces in the direction of X-axis 118 (directed out-of-the-page) and the direction of Y-axis 119 . The actuator may have at least three sets of coils corresponding to each of the axes and the forces that may be produced when the corresponding coils are energized with control currents produced by control electronics 150 . The position of the front end of the rotor is constantly monitored by non-contact position sensors, such as radial position sensors 124 and axial position sensors 126 . The non-contact radial position sensors 124 can monitor the radial position of the front end of the rotor 110 , whereas the non-contact axial position sensors 126 can monitor the axial position of the rotor 110 .
Signals from the non-contact radial position sensors 124 and axial position sensors 126 may be input into the control electronics 150 , which may generate currents in the control coils of the combination radial and axial electromagnetic actuator 101 when it finds that the rotor 110 is deflected from the desired position such that these currents may produce forces pushing the rotor 110 back to the desired position.
At the rear radial AMB 116 is an electromagnetic actuator 128 , radial non-contact position sensors 130 , and control electronics 152 . The rear radial AMB 116 may function similarly to the front radial AMB 114 except that it might not be configured to control the axial position of the rotor 110 because this function is already performed by the front radial AMB 114 . Correspondingly, the electromagnetic actuator 128 may not be able to produce controllable axial force and there may be no axial position sensor.
As described above, FIG. 2 is a detailed cross-sectional view 190 of the front mechanical backup bearing 122 of the electric rotational machine system 100 of FIG. 1 . Details of the axial spring 230 are further discussed in FIGS. 3A to 3C .
FIG. 3A is a detailed half cross-sectional view of a flat spring in loaded condition as implemented in FIG. 2 . There is a gap 305 between the axial spring 230 and the resilient mount cover 235 . The gap 305 is created by a thickness difference in the resilient mount cover 235 . The insertion of a shim 234 between the axial spring 230 and the resilient mount cartridge 237 can be used to adjust a clearance 307 . The clearance 307 allows the axial spring 230 to be in direct contact with the outer race 212 without any interference with the resilient mount cartridge 237 . The axial spring 230 supports the outer race 212 by applying a pre-load compression onto the outer faces 221 of the outer race 212 . The pre-load compression associates to the clamping force discussed above. When the outer race 212 translates due to thermal expansion of the backup bearing inner races 211 , the axial spring 230 deflects outwards into the gap 305 to allow for the thermal expansion while maintaining a similar level of pre-load compression. In some instances when the thermal expansion causes excessive expansion (e.g., machine being overheated), the axial spring 230 can be stopped by the resilient mount cover 235 when the deflection has travelled across the gap 305 . The resilient mount cover 235 therefore acts as a hard stop for deflection of the axial spring 230 upon thermal expansion of the backup bearing inner race 211 .
In some implementations, the axial spring 230 is an annular plate having a suitable thickness, outer diameter, and inner diameter to provide sufficient stiffness for supporting the pre-load compression to the outer race 212 . In some implementations, the axial spring 230 is a wave spring that includes one or more layers of circular, wavy, flat wires. In some implementations, the axial spring 230 is a Belleville washer or spring, having a frusto-conical shape. Other types of axial springs are also contemplated and described in FIGS. 4A-B .
FIG. 3B illustrates the axial spring 230 prior to assembly (i.e., the resilient mount cover 235 has not yet been tightened to the end resilient mount cartridge 237 ). The original shape of the axial spring 230 may be tilted towards the front mechanical backup bearings 122 as illustrated. As the fastener 238 assembles the resilient mount cover 235 to the resilient mount cartridge 237 , the axial spring 230 elastically deforms into the position shown in FIG. 3A . The elastic deformation allows the axial spring 230 to generate the pre-load compression to clamp the front mechanical backup bearings 122 in place. FIG. 3C illustrates the axial spring 230 being deflected as the thermal expansion of the front mechanical backup bearings 122 translates the outer race 212 outwards.
FIG. 4A is a perspective view of an example spring 400 in accordance with the present disclosure. FIG. 4A is a perspective view of an example spring 400 having a circular profile resembling a washer. Spring 400 may have a certain conical curvature for providing pre-load compression. The stiffness of the spring 400 may be varied by using different materials, changing the outer diameter, the inner diameter, and the thickness of the spring 400 . FIG. 4B is a perspective view of another example spring 405 in accordance with the present disclosure. Spring 405 has fingers 407 that may be used to cover a larger outer diameter at a lower stiffness to allow for thermal expansion. Other implementations are possible and are within the scope of this disclosure.
The present disclosure describes embodiments of an axial spring for allowing thermal expansion in a bearing system. Other embodiments and advantages are recognizable by those of skill in the art by the forgoing description and the claims.
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The present disclosure describes a mechanical backup bearing system arrangement to work in conjunction with non-contact magnetic bearings and capable of coping with thermal expansions of the bearing components during operations. Expansions or contractions of an inner or outer race of a bearing can be compensated using particular springs providing a low profile and a proper stiffness. An electric machine system includes a rotational portion and a stationary portion. The electric machine further includes a magnetic bearing configured to support the rotational portion to rotate within the stationary portion. A mechanical back-up bearing resides in a cavity between the rotational portion and the stationary portion. A flat spring is carried by the stationary portion and abutting the back-up bearing.
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This is a divisional of copending application Ser. No. 524,064, filed on Aug. 17, 1983 and now U.S. Pat. No. 4,539,001.
BACKGROUND OF THE INVENTION
This invention relates to a method and catalyst for removing catalyst-poisoning impurities or contaminants such as arsenic, iron and nickel from hydrocarbonaceous fluids, particularly shale oil and fractions thereof. More particularly, the invention relates to a method of removal of such impurities by contacting the fluids with a copper-Group VIA metal-alumina catalyst. The catalyst may be used as a guard bed material in a step preceding most refining operations, such as desulfurization, denitrogenation, catalytic hydrogenation, etc.
Due to scarcity of other hydrocarbon fuels and energy resources in general, shale oil and other hydrocarbonaceous fluids such as those derived from coal, bituminous sands, etc., are expected to play an increasing role in the production of commercial hydrocarbon fuels in the future. Substantial effort has been devoted to the development of cost-efficient refining techniques for the processing of these hydrocarbonaceous fluids. Frequently, these fluids contain contaminants that poison and deactivate expensive and sensitive upgrading catalysts used in hydrogenation and other refining steps to which these hydrocarbonaceous fluids must be subjected before they can be satisfactorily used as sources of energy. In addition, the removal of contaminants such as arsenic may be necessary for environmental protection if the hydrocarbonaceous fluids are employed as fuels, as these contaminants form poisonous compounds.
The prior art has included several methods of removing arsenic from hydrocarbonaceous fluids, such as that described in U.S. Pat. No. 2,778,779 to Donaldson issued on June 14, 1952. Such methods have included the use of metal oxides to remove arsenic from streams of naturally occurring crude oil.
Other processes have been developed for the removal of arsenic present in the parts per billion range from naphthas in order to protect sensitive reforming catalysts. Unfortunately, such processes cannot be applied to shale and other hydrocarbonaceous fluids which often have arsenic concentrations as high as 60 ppm.
Also known, are washing processes employing aqueous caustic solutions to precipitate arsenic salts from the hydrocarbonaceous fluid and extract them into the aqueous phase. See, e.g. U.S. Pat. No. 2,779,715 to Murray issued on Jan. 29, 1957 and D. J. Curtin et al, "Arsenic and Nitrogen Removal during Shale Oil Upgrading", A.C.S. Div. Fuel Chem., No. 23(4), 9/10-15/78. These processes, however, are relatively expensive, cause a substantial amount of fluid to be lost to the aqueous phase, contaminate the hydrocarbon fluid with aqueous solution and present a problem with regard to the disposal of waste caustic solution.
Many patents have issued which are directed to use of a metallic oxide and/or sulfide catalyst such as iron, nickel, cobalt or molybdenum oxide or sulfide or composites thereof on an alumina carrier to remove arsenic and other contaminants from shale oil. See, e.g. U.S. Pat. No. 4,003,829 to Burget et al issued on Jan. 18, 1977, U.S. Pat. No. 4,141,820 to Sullivan issued on Feb. 27, 1979 and U.S. Pat. No. 3,954,603 to Curtin, U.S. Pat. No. 3,804,750 to Myers and U.S. Pat. No. 4,046,674 to Young. While these processes are effective, they employ relatively sophisticated and relatively expensive catalysts which considerably contribute to the processing costs of shale oil.
U.S. Pat. No. 4,354,927 to Shih et al issued on Oct. 19, 1982 describes the removal of catalyst poisoning contaminants such as arsenic and selenium from hydrocarbonaceous fluids particularly shale oil by contact with high-sodium alumina in the presence of hydrogen; saturation of conjugated diolefins is also effected.
Japan Pat. Nos. 5,6095-985; 5,6092-991; and 5,4033,503 to Chiyoda Chemical Engineering Company of Japan describe Group IB catalysts for demetalation; however, these utilize specific supports (not alumina).
The Bearden, Jr. et al U.S. Pat. No. 4,051,015 describes a copper chloride demetalation catalyst.
OBJECTS
It is an object of this invention to provide an improved catalyst and method for removing arsenic from hydrocarbonaceous fluids such as shale oil.
It is another object of this invention to provide an improved catalyst and method for removing arsenic from a hydrocarbonaceous fluid having a relatively high arsenic content.
It is a further object of this invention to provide a catalyst and process for removal of arsenic which does not entail use of an aqueous phase and mixing of said aqueous phase with the hydrocarbon.
It is yet another object of this invention to provide an improved catalyst and method for removing arsenic and other contaminants from hydrocarbonaceous fluids, which method is inexpensive and does not substantially contribute to the processing cost of the fluids.
These and other objects will become apparent from the specification which follows.
SUMMARY
In accordance with one aspect of the invention, there is provided a method for reducing the content of at least one of arsenic, iron and nickel in a hydrocarbonaceous fluid by contacting the fluid with a particulate catalyst consisting essentially of an oxide or sulfide of copper and an oxide or sulfide of a Group VIA metal on a porous alumina support in the presence of hydrogen under sufficient metal reducing conditions. Such metal reducing conditions may involve, e.g., a temperature ranging from about 400° to 900° F., a pressure ranging from about 100 to 3000 psig, and a LHSV of from about 0.1 to 10. By means of the metal reducing process of the present invention, a relatively small amount of hydrogen may be consumed while removing a relatively large amount of metals.
According to another aspect of the invention, there is provided a particulate catalyst consisting essentially of an oxide or sulfide of copper and an oxide or sulfide of a Group VIA metal on a porous alumina support, wherein the total weight of the oxides or sulfides of copper and the oxides or sulfides of the Group VIA metal are present in an amount ranging from about 20 to 75 weight percent, based on the total catalyst, the remainder of the catalyst being essentially alumina. This catalyst is particularly suitable for reducing the content of at least one of arsenic, iron and nickel in a hydrocarbonaceous fluid by contacting the fluid with the catalyst in the presence of hydrogen under sufficient metal reducing conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing the removal of arsenic from shale oil by a copper-molybdenum-alumina catalyst as compared with other demetalation catalysts.
FIG. 2 is a graph showing the removal of nickel from shale oil by a copper-molybdenum-alumina catalyst as compared with other demetalation catalysts.
FIG. 3 is a graph showing the removal of iron from shale oil by a copper-molybdenum-alumina catalyst as compared with other demetalation catalysts.
FIG. 4 is a graph showing demetalation vs. hydrogen consumption for shale oil with a copper-molybdenum-alumina catalyst as compared with other demetalation catalysts.
DETAILED DESCRIPTION
The Group VIA metals referred to herein correspond to the elements of Group VIA of the Periodic Chart of the Elements. The Periodic Chart referred to herein is that version officially approved by the United States National Bureau of Standards (NBS) and the International Union of Pure and Applied Chemists (IUPAC), the elements of Group VIA being chromium (Cr), molybdenum (Mo) and tungsten or wolfram (W). Preferred Group VIA metals are molybdenum and tungsten, especially molybdenum.
Examples of preferred catalysts according to the present invention contain from about 20 to 65, most especially 38 to 46, weight percent CuO and from about 4 to 12, most especially 7 to 9 weight percent MoO 3 . Catalysts in accordance with the present invention may have a pore volume within the range of about 0.4 cc/g and 0.8 cc/g and a surface area within the range of 150 to 250 m 2 /g.
By way of example, retorted shale oil can be partially upgraded by contacting the demineralized ("desalted") oil with a CuMo/Al 2 O 3 guard chamber catalyst in the presence of hydrogen at temperatures of 500°-700° F. In this process, a 42 wt. % copper oxide; 8 wt. % molybdena on alumina catalyst shows demetalation activity equal to or better than conventional hydrotreating catalysts, but requires less hydrogen consumption. As discussed more fully hereinafter, the catalyst has higher nickel removal activity than other (nickel-containing) catalysts. This may be especially significant for in-situ derived shale oils which tend to have higher nickel contents than conventionally retorted oils. Since the catalyst has some hydrogenation activity, it effectively lowers the conjugated diolefin content at mild conditions--something that a Ni/Al 2 O 3 or Cu/Al 2 O 3 catalyst cannot achieve if the feedstock is high in sulfur (≧0.5 wt. %).
Retorted shale oil contains a large number of trace metals such as As, Fe, Ni, V, Co, Se and Zn; As and Fe are the predominant trace elements (>20 ppm). These metals present several processing and product problems:
some arsenic compounds in shale oil are water soluble and can cause pipeline corrosion;
when shale oil is upgraded by delayed coking, most of the metals are rejected in the coke, resulting in a lower quality coke;
upgrading catalysts are irreversibly poisoned by metals deposition;
when burned directly as a fuel, shale oil has potential As 2 O 3 emission problems.
As mentioned previously, there are many methods reported in the literature for arsenic removal, adsorption, extraction, thermal treatment, and chemical additives. Relative to metals in petroleum, arsenic in shale oil is very reactive. Commercial hydrotreating catalysts, when fresh, can easily reduce the arsenic and other metals in shale oil to less than 0.1 ppm under normal hydrotreating conditions (T≧725° F. and LHSV≦0.8). Since metals poison the catalyst's hydrotreating activity, upstream metals removal is preferred.
Most guard chamber operations are carried out in the presence of hydrogen. Although arsenic removal is relatively insensitive to hydrogen partial pressure (i.e. k α (P/P o ) 0 .4) in the 400-2200 psi range, plugging problems have been encountered at lower pressures (<1000 psi). The major catalysts--nickel, cobalt, iron or copper --have poor hydrogenative activity at lower temperatures (≦400° F.) and consequently, cannot eliminate the fouling problems.
The invention may be practiced in a guard bed chamber preferably having a fixed bed of porous particulate material, but a moving bed may also be used. An example of such a particulate material is a copper-molybdenum-alumina catalyst.
The guard bed may be situated in a guard chamber, a closed metal vessel capable of being pressurized. The particles must be capable of promoting deposition of the contaminants thereon when contacted by the hydrocarbonaceous feed under a reducing atmosphere provided by hydrogen at a pressure between 100 and 3000 psig, preferably between 400 and 2500 psig, and at a temperature between 400° and 900° F., preferably between 500° and 750° F.
The hydrocarbonaceous feed is preferably admixed with hydrogen at a ratio ranging from 1000 to 10,000 standard cubic feet (scf) of H 2 per barrel (b) of feed and preferably 2000 to 5000 scf of H 2 /b of feed and the admixed feed is contacted with the particles for a time sufficient to reduce the arsenic and other contaminant content to acceptable levels.
The quantity of material in the guard bed should be sufficient to keep the Liquid Hourly Space Velocity (LHSV), measured in units of volumetric flow rate of feed per unit volume of catalyst, between the values of 0.1 and 10 and preferably between those of 0.5 and 3. This LHSV range corresponds to a residence time for the feed in the guard bed ranging between 0.1 and 10 hours and preferably 0.3 to 2 hours.
The invention may be further illustrated by the Examples which follow:
EXAMPLE 1
Catalyst Preparation
[42% CuO-8% MoO 3 -50% Al 2 O 3 ]
A catalyst was prepared in the following manner: 211 ml. of solution containing 73.0 grams ammonium heptamolybdate (81.5% MoO 3 ) were blended in a muller-mixer with 535 grams of alpha alumina monohydrate powder, a product commercially available as Kaiser Substrate Alumina (SA) from Kaiser Chemicals. Then 454 grams of cupric carbonate (68.85% CuO) were blended into the mixture, after which 200 ml. water were added. The mixture was extruded to one-thirty second inch diameter cylinders, dried at 250° F. and calcined two hours at 800° F.
The catalyst had the following properties:
______________________________________Density, g/ccPacked 0.73Particle 1.41Real 4.57Pore Volume (PV), cc/g 0.489Surface Area, m/g 208Avg. Pore Diameter, Å 94Pore Size Distribution% of PV in Pores of 0-50Å Diameter 17 50-100 22100-150 21150-200 23200-300 11300+ 6______________________________________
EXAMPLE 2
The catalyst of Example 1 was used in five runs for the demetalation of Occidental Shale Oil. Data for this example are shown in Table 1.
TABLE 1__________________________________________________________________________Demetalation of Occidental Shale Oil over (CuMo/Al.sub.2 O.sub.3) CHG 1 2 3 4 5__________________________________________________________________________Reactor ConditionsTemperature, °F. -- 504 556 608 650 701Pressure, psig -- 2200 2200 2200 2200 2200LHSV, vff/hr/vcat -- 1.8 1.8 1.8 1.9 2.0Days on Stream -- 1.3 2.1 2.9 3.6 4.4TLP PropertiesGravity, °API 23.0 23.2 24.6 24.8 25.1 26.4Hydrogen, wt. % 12.04 12.10 12.40 12.35 12.41 12.70Nitrogen, wt. % 1.61 1.47 1.46 1.35 1.32 1.29Sulfur, wt. % 0.67 0.57 0.52 0.50 0.37 0.25Arsenic, ppm 20.0 12.0 11.0 9.6 6.4 3.3Iron, ppm 68.0 4.1 3.3 2.2 1.4 0.9Nickel, ppm 11.0 10.0 9.4 8.4 4.7 1.5H.sub.2 Consumption, scf/b -- 28 -- 197 244 429__________________________________________________________________________
Three catalysts are compared for processing Occidental shale oil. Shell 324 and Harshaw Ni-3266E are feld to be relatively active commercial catalysts for demetalation. Key results are shown in FIGS. 1-4. The results indicate:
The catalyst of Example 1 is less active than Shell 324 for dearsenation, but more active than Harshaw Ni-3266E;
The catalyst of Example 1 is more active than the other catalysts for iron and nickel removal. The approximate 100° F. improvement in iron removal activity is especially significant as iron is the most predominant trace metal in shale oil. Nickel removal is especially important for in-situ generated shale oils which tend to have higher nickel concentrations.
The demetalation/hydrogen consumption selectivity of the catalyst of Example 1 is better than Harshaw Ni-3266E or Shell 324. The selectivity could probably be improved by optimizing the molybdenum content in the catalyst of Example 1.
About 70% of the arsenic removed was retained on the catalyst. This is similar to the amount retained on nickel-containing catalysts. The arsenic compounds are speculated to be reacting with the copper to form stable complexes. Copper-arsenic complexes are abundant in nature (e.g., enargite-3CuS.As 2 S 5 ) and are often a by-product of copper smelting operations. (Note Kirk-Othmer, Encyclopedia of Chemical Technology, Second Edition, Vol. 2, p. 721.
Features of the process of the present invention include the following:
Uses copper-Group VIA metal-alumina catalyst for demetalation.
Retains arsenic on catalyst-probably in the form of copper-arsenic complexes.
Has higher iron and nickel removal activities than nickel-containing demetalation catalysts.
Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives 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 and variations that fall within the spirit and scope of the appended claims.
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There is provided a method and catalyst for removing catalyst-poisoning impurities or contaminants such as arsenic, iron and nickel from hydrocarbonaceous fluids, particularly shale oil and fractions thereof. More particularly there is provided a method of removal of such impurities by contacting the fluids with a copper-Group VIA metal-alumina catalyst. For example, a copper-molybdenum-alumina catalyst may be used as a guard bed material in a step preceding most refining operations, such as desulfurization, denitrogenation, catalytic hydrogenation, etc.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part (CIP) application of U.S. patent application Ser. No. 08/411,620 filed Apr. 5, 1995, now abandoned.
FIELD OF THE INVENTION
The present invention relates to new pharmaceutical formulations of spiramycin. It relates more particularly to new formulations intended to be administered orally.
BACKGROUND OF THE INVENTION
Spiramycin has been commercially available for nearly twenty-five years. However, spiramycin has proven very difficult to administer to man and, more particularly, to children in the form of a solution, suspension or dispersible granule because its bitterness is extremely difficult to mask.
Attempts to mask this bitterness include the formulation described in French published patent application number FR 2,669,533, which discloses spiramycin encapsulated by albumin by a technique which requires the use of organic solvents, such as isooctane, and their removal at the end of the process. This technique, although very efficient at taste-masking, is very expensive because it only allows the manufacture of small quantities of pharmaceutical composition and it necessitates stages of solvent recycling which are long and costly.
SUMMARY OF THE INVENTION
The present invention has made it possible to prepare spiramycin formulations having an enhanced taste without using solvent for its preparation. This enhanced taste masks the bitterness of spiramycin without adversely affecting bioavailability or stability of the spiramycin. The formulation comprises spiramycin and acesulfame, particularly potassium acesulfame.
The new pharmaceutical forms of spiramycin according to the present invention, which may also include flavoring agents, are intended to take the form of doses (sachets, bottles or packs with a measure, for example) containing a granulated powder to be dissolved or to be dispersed in water prior to administration to the patient.
This new granulated form, which can be suspended in water immediately before use, offers the following advantages:
ease of use during ambulatory treatment
accuracy of the unit dosage
easy suspension or dissolution in water
easy absorption.
Numerous various formulation trials attempting to mask the bitterness have been undertaken. None of them gave satisfactory results as regards the taste of the aqueous suspension obtained or as regards the bioavailability of the spiramycin after absorption. However, the association between potassium acesulfame and spiramycin according to the present invention surprisingly has made it possible to achieve this objective.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
New granulated pharmaceutical forms of spiramycin for oral administration according to the present invention are prepared by wet granulation of the spiramycin and sucrose, preferably in a weight ratio of about 1/1 to about 1/9, followed by preparing in a dry state a mixture of the granules previously obtained, acesulfame, flavorings and any remaining sucrose.
The new formulations according to the invention preferably comprise about 100,000 to about 5,000,000 IU spiramycin, about 10 to about 20 mg potassium acesulfame, about 20 to about 200 mg flavorings and about qs 1 to about 10 g sucrose. According to one preferred embodiment, such formulations comprise 375,000 IU spiramycin, about 10 to about 20 mg potassium acesulfame, 60 mg flavorings and about qs 3 g sucrose. These formulations are preferred. One of ordinary skill in the art will appreciate that the formulations of the present invention may be adapted according to the desired masking of the bitterness of the active ingredient by adding more or less potassium acesulfame. The flavorings may also be adapted to the taste and to the age of the child.
These formulations may be presented either in the form of doses as mentioned above or in the form of a solution or suspension prepared immediately before use.
The invention will be described more fully with the aid of the following examples, which should not be considered as limiting the invention.
COMPARATIVE EXAMPLE 1
______________________________________spiramycin 86.190 mg (375,000 IU)Eudragit E 100 ® 70.00 mgmannitol qs 950.00 mgsodium saccharinate 25.00 mgstrawberry flavoring 40.00 mganhydrous colloidal silica 12.50 mgcellulose (microcrystalline) 25.00 mgpolyvidone 100.00 mgsucrose 97.50 mg 1250.00 mg______________________________________
Trials with this type of formula were stopped, in spite of the success of the taste masking, because of poor bioavailability.
COMPARATIVE EXAMPLE 2
Development of a simple and rational formula by preparation of a granule (concentrated) composed of sugar and spiramycin; and flavoring of the primary granule by the addition, in an external phase, of sweeteners and flavorings simply by mixing.
The manufacture of the primary granule is performed in a Turbosphere mixer-granulator-drier and the preparation of the final mixture in a gravity mixer.
Theoretical unit formula:
______________________________________spiramycin base 81.156 mg (375,000 IU)sucrose qs 1000.00 mg sucrose (Alveo sugar) 1960.00 mg externalbanana flavoring 40.00 mg phase 3000.00 mg______________________________________
A bioavailability study demonstrated the bioequivalence of the granule of comparative trial 2 and of commercial syrup; however, the taste acceptability tests showed that the flavoring of the product requires improvements.
COMPARATIVE EXAMPLES 3 AND 4
The sweeteners commonly used (sodium saccharinate, sodium cyclamate) could not be selected because of the insufficient organoleptic effects.
An acceptability test was carried out on two of these formulations (one with sodium saccharinate (Example 4) and one with aspartame (Example 3)). The general formulations and results are indicated in Table 1 below. For aspartame, the taste acceptability test is satisfactory but the product interacts with spiramycin, thereby making its use impossible.
COMPARATIVE EXAMPLE 5
An attempt to mask the bitterness of spiramycin by association with xanthan gum. The general formulation is shown in Table 1. Results of taste testing were inconclusive but low.
EXAMPLE 6
The manufacture of sachets is carried out in 3 phases:
(a) Preparation of a concentrated primary granule (165 mg per sachet of 3 g containing 375,000 IU of spiramycin) in a Moritz mixer-granulator-drier:
______________________________________per sachet of 3 g______________________________________spiramycin base 84.081 mg (375,000 IU)sucrose (superfine sugar) qs 165.00 mgwater about 5% by mass______________________________________
During the granulation, the product is heated with the aid of a jacket up to about 55° C. The stirring is carried out at about 100 revolutions/minute for 30 minutes. For the drying, the stirring is carried out at about 20 revolutions/minute while the temperature is maintained but while the pressure is reduced to between 6 and 20 KPa for 60 minutes.
The product is then cooled to room temperature over about 30 minutes.
The granule is sieved on a screen with a mesh of 0.71 mm.
(b) Preparation of the final granule in a cubic gravity mixer
______________________________________primary granule 165.00 mgpotassium acesulfame 10.00 mgpowdered strawberry flavoring 30.00 mgpowdered raspberry flavoring 30.00 mgsucrose* qs 3000.00 mg______________________________________ *superfine sugar and Alveosugar in a 1/1 ratio approximately.
(c) Distribution of the final mixture in an amount of:
3 g for the 375,000 IU dosage
6 g for the 750,000 IU dosage
12 g for the 1,500,000 IU dosage
per sachet of paper/aluminum/polyethylene complex.
EXAMPLE 7
The procedures of Example 6 are repeated using qs 1 g sucrose in phase (a) per sachet of 3 g and 20 mg potassium acesulfame in phase (b).
The preparations described above (Examples 2-7) were submitted to taste testing and rated on a scale of 1 to 20 where 20 was the highest score. The results are set forth in Table 1.
TABLE 1______________________________________COMPARATIVE EXAMPLES 2 TO 5 INVENTIONC.sub.5 C.sub.2 C.sub.4 C.sub.3 7 6______________________________________spira- 375,000 375,000 375,000 375,000 375,000 375,000mycin(IU)sucrose qs 1 g qs 1 g qs 1 g qs 165 mgstarch 3.5 mgxanthan 15 mggumPVP 100 mgK ace- 20 mg 10 mgsulfameaspartame 10 mgsacchari- 25 mgnateEudragit 70 mgE ®mannitol 800 mgflavorings 20 mg 40 mg 40 mg 20 mg 60 mg 60 mgsucrose qs 2.5 g qs 3 g qs 1.25 qs 3 g qs 3 g qs 3 gscore out 6.25 poor 14 15 accept-of 20 non-bio inter- ableremarks equiva- action lent between spiramycin and aspartame______________________________________
The formulations according to the present invention (Examples 6 and 7) show a marked improvement compared with the prior art formulations regarding masking of the taste and aftertaste of spiramycin.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than the specification, as indicating the scope of the invention.
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New formulations of spiramycin suitable for oral administration, particularly for children, comprise spiramycin and potassium acesulfame. These formulations mask the bitterness of spiramycin without adversely affecting the bioavailability or stability of the spiramycin. Preparation by wet granulation followed by dry state mixing is also disclosed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to materials for the manufacture of nonwoven tissues having particular softness and strength. The nonwoven material segment of the overall wiper market has grown due to the economy of such products, as well as the ability to tailor the wipers for specific applications. For example, nonwoven wipers are available having absorbency properties particularly suited for oil wiping, for food service wiping and for wiping of high technology electronic parts. Such nonwoven materials may be manufactured by a number of known processes, including wet-forming, air-forming and extrusion of thermoplastic fibers. The present invention is related to an improvement in nonwoven facial tissues formed using a meltblowing process to produce microfibers, incorporating particular cellulosic fibers having utility and diverse applications and particularly unique softness.
2. Description of the Pertinent Art
U.S. Pat. No. 4,426,417 discloses a wiper comprising a matrix of nonwoven fibers having a basis weight of 25 to 300 gsm including a meltblown web holding a staple fiber mixture therein. The matrix contains up to 90% fiber blend of which 90% is synthetic fibers.
Meltblown nonwoven microfiber materials are known and have been described in a number of U.S. Patents, including U.S. Pat. No. 4,328,279 to Meitner and Englebert, U.S. Pat. No. 4,298,649 to Meitner and U.S. Pat. No. 4,307,143 to Meitner. The preparation of thermoplastic microfiber webs is also known and described, for example, in Went, Industrial and Engineering Chemistry, Volume 48, No. 8 (1956), pages 1342 through 1346, as well as in U.S. Pat. Nos. 3,978,185 to Buntin, et al., 3,795,571 to Prentice and 3,811,957 to Buntin. These processes generally involve forming a low viscosity thermoplastic polymer melt and extruding filaments into a converging air stream which draws the filaments to fine diameters on the average of up to about 10 microns, which are then collected to form a nonwoven web. The addition of pulp to the air stream to incorporate the pulp into the meltblown fiber web is also known and described in U.S. Pat. No. 4,100,324 to Anderson, Sokolowski and Ostermeier.
While tissues produced in accordance with the disclosures of these patents have, in some cases, achieved good acceptance for a number of wiping applications, it remains desired to produce a nonwoven facial tissue having extremely high softness while maintaining good wiping properties, i.e., the ability to wipe quickly and having good strength. It is desired to produce such a facial tissue at a cost consistent with disposability and having strength properties for rigorous wiping applications. Wipers of the present invention attain to a high degree these desired attributes.
SUMMARY OF THE INVENTION
The present invention relates to a single-ply nonwoven facial tissue having a basis weight of between 20 and 50 g/m 2 and including thermoplastic microfibers having an average diameter in the range of up to about 10 microns and cellulosic fibers. Further, the invention relates to such improved tissues having not only excellent clean wiping properties but also good tactile and physical properties such as softness and strength. The tissue of this invention comprises a matrix of microfibers, preferably meltblown thermoplastic fibers having distributed throughout cellulosic fibers. Thermoplastic fibers are present in an amount of between about 30 and about 80 weight percent. Preferred embodiments include microfibers formed from polypropylene and mixtures of staple fibers having a coarseness coefficient below about 20, preferably about 15.
The tissue of this invention has been demonstrated to possess excellent clean wiping properties as determined by wiping residual tests, excellent absorbency for both oil and water as demonstrated by capillary suction tests and oil absorbency rate tests with both low and high viscosity oils and softness as demonstrated by softness facial tests against premium quality facial tissues. When compared with conventional facial tissues, the tissues of this invention exhibit a unique combination of performance, physical properties and the economy of manufacture.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the process useful to prepare webs of the present invention.
FIG. 2 is an enlarged view of a partial cross section of an unbonded tissue web produced in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the invention will be described in connection with preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and the scope of the invention as defined by the appended claims.
To further illustrate the preparation of the fibrous sheet products of this invention, examples will be provided. To assist in understanding the examples, the following definitions and descriptions of methods employed will be helpful:
(1) the term "basis weight" as used herein refers to the weight in grams of one square meter of the particular fibrous sheet in question;
(2) the term "tensile strength" is the force in grams required to rupture a three inch wide sample of the dry fibrous sheet; the tensile strength is measured in both the machine direction (MD) and the cross machine direction (CD) using a Model 1130 Instron tester with a four inch jaw span and a crosshead speed of ten inches per minute;
(3) the term "% stretch" is the elongation at break of a sample of the fibrous sheet in the machine direction (MD) converted to percent. This measurement is also obtained on the Model 1130 Instron tester at the point of break;
(4) the term "Softness Test Rating" refers to the subjective feeling of a fibrous sheet, such as facial tissue, when touched. The values reported herein were obtained by averaging the values determined by at least eight trained sensory panelists, who evaluate each sample for stiffness, surface depth, and abrasiveness by comparing the sample to standard samples having a softness rating from 1 (least soft) to 15 (most soft).
The standards and samples to be tested are first subjected to the same temperature and relative humidity for and extended period of time (24 hours or longer).
One specimen of each standard needed is then placed in a row of ranked order. All specimens (including the standards) are placed flat on the table. The test specimen and the appropriate standard specimens are felt by placing the hand on the specimen with thumb and fingers spread with the base of the palm near a corner and the thumb and little finger each approximately parallel to an edge. The finger tips are moved toward the base of the palm and the thumb tip toward where the middle and index fingers join the palm so that (1) a loose mass is gathered in the palm and (2) two or more thicknesses project beyond the thumb across the middle and index fingers. The hand is then lifted and, if necessary, the thumb and fingers are manipulated to position the mass so it can be felt where the middle and index fingers join the palm. The thumb is placed on the thicknesses that lie across the middle and index fingers.
The fingers are opened and closed repeatedly, each time starting with the little finger and ending with the index finger. The mass is crushed lightly in the palm each time the fingers close, letting the fingers slide on the specimen as they will.
At the same time, the thumb is moved back and forth lightly on the thicknesses between it and the index and middle fingers. Limpness and surface texture are evaluated simultaneously as described below and combined with equal weight for a softness rating to the nearest 0.1 standard value. Most of the limpness evaluation is based on the pressure felt from the mass as the fingers open and close. Most of this pressure is felt where the middle and index fingers join the palm.
Most of the surface texture evaluation is based on the feel of the tissue between the thumb and the index and middle fingers as they move back and forth in opposite directions. The degree of unpleasant harshness and also the degree to which a pleasing velvet-like "nap" exists is evaluated. These are combined at equal weight in the evaluation of surface texture. Each sheet is rated to the nearest 0.1 scale interval.
(5) The term "Tensile Energy Absorption" is the area under the stress/strain relationship curve for a sample of the dry or wet fibrous sheet.
(6) The term "Invariant Tensile Energy Absorption" is the square root of the product of the tensile energy absorption in the machine direction and the cross direction for a sample of the fibrous sheet.
The meltblown fiber component of the present invention may be formed from any thermoplastic composition capable of extrusion into microfibers. Examples include polyolefins such as polypropylene and polyethylene, polyesters such as polyethylene terephthalate, polyamides such as nylon, as well as copolymers and blends of these and other thermoplastic polymers. Preferred among these for economy as well as improved wiping properties is polypropylene. The cellulosic fiber component should include fibers having a length in the range of about 1/4 to about 4 mm and an average length of about 1 mm. Preferably the fibers are hardwood pulp or a fine textured softwood. Fibers should have a coarseness coefficient below about 20 and preferably below about 15 milligrams per meter. These compositions, it will be recognized, may also contain minor amounts of other fibers and additives which will not adversely affect properties of the resulting tissues.
A process for making the tissue material of the present invention may employ apparatus as generally described in U.S. Pat. No. 4,100,324 to Anderson, Sokolowski and Ostermeier which is incorporated herein by reference. In particular, reference to FIG. 1 hereof, in general, a supply 12 of polymer is fed from an extruder (not shown) to die 14. Air supply means 16 and 18 communicate by channels 20 and 22 to a die tip 24 through which is extruded polymer-forming fibers 26. Picker 28 receives bulk waste fibers 30 and separates them into individual fibers 32 fed into channel 34 which communicates with air channel 36 to a die tip 24. These fibers are mixed with meltblown fibers 26 and incorporated into a matrix 38 which is compacted on forming screen 40 moving on rollers 42 and 44 between roll 44 and pattern roll 48. The compacted matrix may be sprayed with water by water spray 46 before being embossed. From the embossing rolls, the matrix is fed between two calender rolls 50 and 52 and then fed to reel 54 for later conversion.
The embossing pattern is preferably selected to impart favorable textile-like tactile properties while providing strength and durability for intended use. The temperature of at least one of the rolls 44 or 48 should be in the range from about 150° to about 300° F. and preferably about 200° F. where meltblown fibers are polypropylene and the fibers are hardwood and the tissue speed between rolls 44 and 48 is about 100 feet per minute.
The bond pattern will preferably result in individual embossments over about 15% to about 35% of the material surface and preferably about 20% to about 30%. The concentration of individual bonds is preferably in the range of about 100 to 1,500 bonds per square inch. The embossing pressure should not exceed about 7000 psi. Preferably the pressure is between about 250 and about 5000 psi. The embossing roll may be either fabric or metal. For the preferred embossing areas, a pressure in the range of from about 70 pli to about 225 pli is preferred and more preferably at least 100 pli for 25% bond area. For a different bond area, the preferred pressure may be obtained by multiplying the ratio of percent areas to maintain constant psi on an individual bond point.
The embossed area should consist of individual fibers fused together at intersections between fibers but not fused to a point where the fibers are not discrete. The embossed areas should have a tissue thickness of about 1/3 to 2/3 of the original thickness of the tissue. Preferably the thickness is about 1/2 of the original thickness.
When rapid fiber quenching is desired, the filaments 26 may be treated by spray nozzle 56, for example, during manufacture. The material may be treated for water wettability with a surfactant as desired. Numerous useful surfactants are known and include, for example, anionic and ionic compositions described in U.S. Pat. No. 4,307,143 to Meitner. For most applications requiring water wettability, the surfactant will be added at a rate of about 0.15% to about 1% by weight on the tissue after drying.
Turning to the schematic illustration of FIG. 2, an embodiment of wiper material of the present invention will be described. As shown after embossing, wiper 58 is formed from a microfiber web incorporating a generally uniform dispersion of hardwood fibers 62. The embossed regions are shown at points 64 and 66. While it is not desired to limit the invention to any specific theory, it is believed that the improved performance is obtained by the hardwood fibers separating the fine microfibers of the thermoplastic and producing voids for absorption of liquids. Furthermore, the nature of the fibers is believed to contribute to the improved texture, wettability and clean tissue properties. Further, the controlled bond area and embossing temperature and pressures result in a tissue having a large number of embossed points in which the fibers are discrete but reduced in height by about 1/3 to 2/3. Depending upon the particular properties desired for a tissue, the percent of hardwood fibers in the matrix may vary in the range from about 20% to about 70% by weight with the range of about 40% to 60% by weight preferred. In general, the greater amount of cellulosic fibers added, the more improved will be the clean tissue capacity properties. The basis weight will also vary depending upon the desired tissue applications, but will normally be in the range of about 20 to about 50 g/m 2 and preferably in the range of about 25 to 30 g/m 2 .
Preferably, the tissue of this invention has a Softness Test Rating of at least about 8 and an Invariant Tensile Energy Absorption of at least about 15. More preferably, the tissue has a Softness Test Rating of at least about 9.5 and most preferably about 10. More preferably the Invariant Absorption is at least about 20, most preferably about 30.
EXAMPLES
The invention will now be described with reference to specific examples. The invention will be described in reference to certain tests carried out on material of this invention, as well as conventional facial tissues. These tests are performed as follows:
EXAMPLE I
Using the apparatus assembled generally as described in FIG. 1 having a picker set for feed roll to nose bar clearance of 0.003 inches, nose bar to picker distance of 0.008 inches and picker speed of 3200 RPM, polypropylene was extruded at a barrel pressure of 312 PSIG at a temperature of 537° F. to 609° F. to form microfibers with primary air at 506° F. at a fiber production rate of 32#/hr. To these microfibers in the attenuating air stream was added an indicated weight % of a mixture of cellulosic fibers. The resulting 8 matrixes were embossed at a temperature of 200° F. and a pressure of 125 pli in a pattern covering 25% of the surface area of about 800 bonds per square inch. The eight samples (1-8) were compared to the conventional commercial products on the basis of tensile strength and softness. The commercial products compared are included in Table 1 as No. 9--Puff® and No. 10--Special Touch®. The result of the comparison is present in Table 1 below.
TABLE 1______________________________________Sample I.D. #1 #2 #3 #4 #5______________________________________Basis Weight-Gsm 34.0 33.2 26.9 35.8 28.6Pulp/Poly Ratio 70/30 70/30 70/30 50/50 50/50Tensile Strength-gms/3"MD Dry 1015 1174 1137 1138 1116% MD Stretch 17.2 13.0 14.1 16.1 19.7CD Dry 818 743 532 640 621% CD Stretch 50.5 50.3 58.9 53.9 44.4CD Wet 906 927 653 722 713% CD Wet -- -- -- -- --Absorbent Rate 3.4 3.8 6.0 6.0 2.6Softness TestRating 10.7 10.6 10.9 10.8 10.7Stiff 2.7 2.6 2.3 2.7 2.4Surface Depth 8.7 8.4 8.5 8.5 8.1Abrasive 2.6 2.5 2.5 2.1 2.1Absorbency-Gm Fiber/Gm H.sub.2 O 7.07 6.83 7.85 7.19 7.23Gm/4 × 4 51.90 49.86 44.76 56.66 46.26______________________________________Sample I.D. #6 #7 #8 #9 #10______________________________________Basis Weight-Gsm 29.3 33.6 28.6Pulp/Poly Ratio 50/50 50/50 50/50Tensile Strength-gms/3"MD Dry 1411 1258 1438 1451 1657% MD Stretch 25.4 18.0 28.5 26.9 23.1CD Dry 803 826 913 642 853% CD Stretch 52.2 46.9 493 4.8 7.2CD Wet 914 856 859 195 197% CD Wet -- -- 44.2 7.2 9.9Absorbent Rate 3.0 3.6 -- 15.5 11.0SoftnessRating Test 10.6 10.0 -- 8.1 8.9Stiff 2.5 3.0 -- 4.5 3.9Surface Depth 8.3 7.6 -- 5.5 6.6Abrasive 2.7 2.2 -- 2.1 2.5Absorbency-Gm Fiber/Gm H.sub.2 O 6.88 6.78 -- 9.58 10.47Gm/4 × 4 43.39 49.81 -- 59.5 89.7______________________________________
EXAMPLE II
Sample #8 was compared to two commercial products on the basis of tensile energy absorption and the invariant tensile energy absorption. The results are present in Table 2 below.
TABLE 2______________________________________ Tensile Energy Absorption g-cm/cm.sup.2 #8 #9 #10______________________________________MD 40.84 15.24 23.89CD 41.08 2.14 4.49Wet CD 32.78 2.81 6.12Invariant 40.96 5.7 10.3______________________________________
As is demonstrated by the above Examples, the tissue material of the present invention provides a unique combination of excellent absorbent properties while having softness and strength. It is thus apparent that there has been provided, in accordance with the invention, a tissue material that fully satisfies the objects set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art 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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Tissue comprising a matrix of nonwoven fibers having a basis weight generally in the range of about 25 to 50 gsm. The matrix is a meltblown web having incorporated therein staple fibers. The combination provides highly-improved tissue properties as well as strength and absorbency required for many tissue applications. The tissues may be formed by a conventional meltblowing process involving extrusion of a thermoplastic polymer as a filament in air streams which draw and attenuate the filaments to fine fibers, having an average diameter of up to about 10 microns. The staple fibers may be added to the air stream, and the turbulence produced where the air streams meet results in a uniform integration of the staple fibers into the meltblown web. The matrix may contain from about 30 to about 80 weight percent polymer and have a subjective softness rating of at least about 10.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a divisional application of U.S. patent application Ser. No. 12/052,194 for Straight Through Cement Mixer which was filed on Mar. 20, 2008 and which was in turn a continuation in part application of U.S. patent application Ser. No. 12/021,415 for Straight Through Cement Mixer which was filed on Jan. 29, 2008 now abandoned. Applicant is the sole inventor of U.S. Pat. No. 6,749,330 that issued on Jun. 15, 2004 for Cement Mixing System for Oil Well Cementing. Applicant also is sole inventor of U.S. Pat. No. 5,571,281 that issue on Nov. 5, 1996 for Automatic Cement Mixing and Density Simulator and Control System and Equipment for Oil Well Cementing; is one of the co-inventors of U.S. Pat. No. 5,355,951 that issued on Oct. 18, 1994 for Method of Evaluating Oil or Gas Well Fluid Process; and is one of the co-inventors of U.S. Pat. No. 5,046,855 that issued on Sep. 10, 1991 for Mixing Apparatus.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is a high efficiency, high energy slurry mixer used primarily to mix oil field cement in a recirculating system for cementing the casing in oil and gas wells. The cement mixer mixes dry powder with water and recirculated slurry to create the cement mixture. The cement mixer employs a straight through design that is easier to clean than previous designs and which can be seen straight through when the connection at the dry powder inlet is removed from the mixer. The cement mixer also has increased number and volume of annular water flow openings and recirculation openings which allows for more water and slurry flow with less erosion to the mixer surface than previous designs. The previous design did not allow for more recirculation and water jets because there was not room to add them. The new design allows the mixer surfaces to be manufactured with less expensive materials without sacrificing performance and life, thereby reducing the cost of the equipment. The present design eliminates most of the wear problems experienced in earlier designs resulting in the equipment lasting longer before repair or replacement is required.
2. Description of the Related Art
The discussion regarding related art appearing in U.S. Pat. No. 6,749,330 is hereby included by reference. The cement mixer design taught in U.S. Pat. No. 6,749,330 had several problems. First, the earlier mixer was not of a straight through type. That earlier mixer included 1 st and 2 nd elbows (associated with reference numerals 114 and 116 in the patent) in the central recirculation line 54, and included a curved inlet 52 for the dry bulk cement. Because of this design, it was more difficult to flush out and clean the inside of the mixer. Also, it was not possible to see straight through the mixer by breaking open the piping connection at the inlet 52, thus making it more difficult to see inside the mixer to troubleshoot or determine if it was clean when doing maintenance.
Further, the central recirculation line of that earlier mixer was just one additional surface which could be eroded by the abrasive recirculated cement slurry contained within its interior.
Also, the four annular water jets of the earlier mixer had less flow capacity, resulting in higher velocity of liquid streams within the mix chamber to obtain comparable flow rates and thus more erosion of the interior mixer surfaces due to the abrasion caused by the abrasive sand in dirty mix water. Additionally, the earlier mixer employed a somewhat complicated design having multiple passageways, all of which are susceptible to erosion by the dirty mix water. The erosion resulted in more equipment maintenance and shorter equipment life. In an attempt to protect the earlier mixer from erosion, some of the surfaces were either hard coated or constructed of heat treated stainless steel which added to the cost of the equipment.
The present invention addresses each of these problems.
One object of the present invention is to provide a straight through design without any internal centrally located recirculation or water jet pipes that is less inclined to foul and easier to clean than previous designs. Also, this straight design allows the mix chamber of the present invention to be viewed when the connection at the dry powder inlet is broken.
A second object of the present invention is to eliminate the need for a central recirculation line by having more complete coverage in the mixing chamber by employing more annular jets.
An additional object of the present invention is to provide a mixer that employs recirculation jets located upstream of its water jets
A further object of the present mixer is to increase the number and capacity of the annular water flow openings thereby allowing greater water flows with less velocity. The path of recirculation and water flows is such that they do not directly impact the mixer sides and they cause less erosion to the mixer surface than with previous designs. Another object of the present invention is to provide a high performance mixer that has less internal erosion.
A further object of the present invention is to provide a mixer that can be manufactured with lesser expensive materials to thereby reduce the manufacturing cost of the mixer.
A further object of the present invention is to provide a mixer that is less complex in design and therefore reducing manufacturing cost and simplifying maintenance.
Still a further object of the present invention is to provide a mixer that, due to the reduced erosion, will have a longer life and required less maintenance than previous designs. Also disassembly and repair is much simpler with this design.
Another object of the present invention is to provide a smaller, more compact and lighter weight cement mixer.
An additional object of the present invention is to provide a five jet design which allows for more recirculation jets and more water jets than previous designs, resulting in more thorough mixing and better wetting of the cement powder.
An additional object is to have the recirculation jets extending into the dry bulk chamber so as to form a star shape in the bulk inlet chamber which serves to help break up or disperse the incoming dry powder.
These and other objects will become more apparent upon further review of the referenced drawings, detailed description, and claims submitted herewith.
SUMMARY OF THE INVENTION
The present invention is a cement mixing method and a mixer used in that method for mixing cement that will be used in cementing oil well casings. The mixer is of the “recirculating” type with variable high pressure water jets. Typically, this type of mixer discharges cement slurry from its outlet end into a diffuser and then into a mixing tank. A recirculation pump is attached to the mixing tank that circulates the already mixed slurry contained in the mixing tank back to recirculation flow inlets provided on the mixer to provide more mixing energy and to provide an opportunity to sample the slurry density. Also typically a mix water pump is connected to a supply of mix water and pumps mix water to a mix water inlet provided on the mixer. The mix water inlet supplies mix water to water jets in the mixer. The water jets control the mixing rate and add mixing energy. Bulk cement is added at the dry bulk cement inlet of the mixer. In general, most of the currently used cement slurry mixers have the above characteristics, some doing a better job than others. The present invention is for use in the same type of environment and in association with the same type of equipment as the mixer taught in U.S. Pat. No. 6,749,330 and the teaching regarding associated equipment from that patent is hereby included by reference.
Beginning at the inlet end or upstream end of the mixer and moving toward the outlet end or downstream end of the mixer, the mixer is provided at its inlet end with a straight bulk cement inlet for admitting dry powder cement into a mixing chamber that is located internally within the mixer housing.
Adjacent to and downstream of the dry bulk cement inlet, the mixer is provided with two recirculation flow inlets that both communicate with a recirculation manifold. The recirculation manifold supplies recirculated cement slurry to five annular recirculation jets that are located around the inside of the mixing chamber downstream of the bulk inlet chamber and the dry bulk cement inlet. For purposes of clarity, the interior of the mixer will be described as being divided into two areas: the bulk inlet chamber and the mixing chamber. The first area is the bulk inlet chamber which extends from the inlet to the recirculation jets. The second area is the mixing chamber which extends from the recirculation jets to the outlet of the mixer. Each recirculation jet or outlet is defined by two structures within the mixer. One structure is the common wall that separates the bulk inlet chamber from the recirculation jets and the other structure is the common wall that separates the recirculation jets from the mix water manifold. The recirculation outlets discharge inwardly at an angle into the mixing chamber.
Adjacent to the recirculation flow inlet, the mixer is provided with a mix water inlet. The mix water inlet communicates with a water manifold that supplies water to five annular water jet orifices provided within the mixing chamber downstream of the recirculation jets. The mix water manifold is defined by three structures within the mixer. One structure is the common wall that separates the recirculation manifold from the mix water manifold. A second structure is the outer housing for the mixer, and a third structure is a rotatable flow adjustment plate of a water metering valve. Grooves are provided in the surfaces that are adjacent to the rotatable water metering valve element to accommodate pressure face seals to contain water pressure within the mix water manifold. A groove is also provided in a fixed orifice plate for a radial seal to secure the fixed orifice plate to the mixer housing so that fluid does not leak out of the mixing chamber at the junction where the fixed orifice plate is secured to the housing.
As shown in FIG. 3 , spacers that are slightly larger in thickness than the rotatable flow adjustment plate are provided surrounding the rotatable flow adjustment plate to allow the flow adjustment plate sufficient clearance between the wall of the water manifold and the fixed orifice plate so that the flow adjustment plate can be rotated. The mixer is provided with a mix water adjustment input means consisting of a fixed orifice plate containing the annular water jet orifices and rotatable or movable water meter valve element or flow adjustment plate with cut away openings therethrough. The movable flow adjustment plate is located adjacent to the fixed orifice plate and between the water manifold and the fixed orifice plate. The movable flow adjustment plate is provided with a handle for rotating the movable flow adjustment plate relative to the fixed orifice plate.
The fixed orifice plate and the rotatable flow adjustment plate cooperate to control the flow of water through the water jet orifices. The position of the movable flow adjustment plate relative to the fixed orifice plate controls the flow of water through the five annular water jets by more fully aligning the cut away openings of the movable flow adjustment plate with the metering slots of the fixed orifice plate, or alternately, by moving the openings more completely out of alignment with the slots. As the movable flow adjustment plate is rotated in a counter clockwise direction, the cut away openings of the moveable flow adjustment plate move so that they align longitudinally within the mixer more completely with their corresponding annular water jet orifices provided in the fixed orifice plate to allow more water to pass from the water manifold through the openings and slots in the movable and fixed orifice plates and out the annular water jet orifices into the mixing chamber of the mixer. Alternately, when the moveable flow adjustment plate is rotated in a clockwise direction, the cut away openings of the moveable flow adjustment plate move out of alignment longitudinally within the mixer with their corresponding annular water jet orifices provided in the fixed orifice plate to allow less water to pass from the water manifold through the movable flow adjustment plates and the fixed orifice plates and out the annular water jet orifices into the mixing chamber of the mixer.
The water jet orifices are angled in orientation so that their discharge is directed inwardly towards the mixing chamber. All of the existing technology with annular adjustable orifices is aligned in an axial direction. These axial designs require the flow direction to be “turned” or deflected beyond the jet to hit the desired mixing chamber location. The turning of high velocity flow causes high wear on mixer parts.
Also, the water jets are located axially downstream of the recirculation jets. This allows for more compact construction, much lower production cost, and easier maintenance.
The five annular recirculation jets are located axially upstream within the mixing chamber relative to the five annular water jets so that the recirculation jets discharge into the mixing chamber upstream of the discharge from the annular water jets. The five jet design allows for more recirculation jets and more water jets than previous designs, resulting in more thorough mixing (better wetting of powder).
The mixer employs equal numbers of recirculation jets and water jets and so that the numbers of each type of jets are balanced. Although odd numbers of recirculation and water jets are preferred, even numbers of these jets are also possible.
The evenly spaced water jets deliver mix water non-axially to the mixing chamber downstream of where the recirculation jets deliver recirculation flow. This arrangement is important for several reasons. The location of the water jets tends to intersect with and further mix the slurry which was introduced upstream in the mixing chamber, thus enhancing mixing. Existing technology with annular adjustable orifices alternate rather than intersect the discharge from the recirculation jet flow. Also, the location of the water jets downstream of the recirculation jets also tends to protect the internal surfaces of the mixing chamber from abrasion by the sand and grit contained in the recirculated cement slurry flowing out of the recirculation jets or by sand contained in unclean water flowing out of the water jets when the water source is unclean.
Finally, an outlet for the mixer is provided at the outlet end of the mixer. The mixture of cement leaves the mixing chamber of the mixer through the outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an inlet end view of a cement mixer constructed according to a preferred embodiment of the present invention.
FIG. 2 is a right side view of the cement mixer of FIG. 1 .
FIG. 3 is a cross sectional view taken along line 3 - 3 of FIG. 1 .
FIG. 4 is a cross sectional view taken along line 4 - 4 of FIG. 3 showing the mix water manifold and the star like appearance of the recirculation jets when viewed from this perspective.
FIG. 5 is a cross sectional view taken along line 5 - 5 of FIG. 3 showing the rotatable flow adjustment plate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and initially to FIGS. 2 and 3 , the present invention is a cement mixing method and the mixer 20 used in that method for mixing cement that will be used in cementing oil wells. The overall typical system and equipment within which the mixer 20 is likely to be used are taught in U.S. Pat. No. 6,749,330. That teaching is incorporated herein by reference.
As explained in detail in U.S. Pat. No. 6,749,330, typically a cement mixer discharges from its outlet end into a diffuser and subsequently into a mixing tank. A recirculation pump is attached to the mixing tank and recirculates the contents of the mixing tank to recirculation flow inlets provided on the mixer. And, typically a mix water pump is connected to a supply of mix water and pumps that mix water to a mix water inlet provided on the mixer. Also, bulk cement is pneumatically delivered to the dry bulk cement inlet of the mixer. It is the cement mixer 20 that is the subject of the present invention. A preferred embodiment of the invention is shown in the attached drawings and will be more fully described hereafter.
Referring to FIG. 3 , the mixer 20 is shown in cross sectional view. For purposes of clarity, the interior of the mixer 20 will be described as being divided into two areas: a bulk inlet chamber 19 and a mixing chamber 6 . The first area is the bulk inlet chamber 19 which extends from the inlet 1 to the recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E. The bulk inlet chamber 19 receives the dry powder cement from the inlet 1 and conveys it to the second area which is the mixing chamber 6 . No mixing occurs in the bulk inlet chamber 19 . The mixing chamber 6 extends from the recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E to the outlet 7 of the mixer 20 and it is in the mixing chamber 6 where the cement powder is mixed with the recirculated slurry and mix water.
The mixer 20 is provided at its inlet end 15 with a straight bulk cement inlet 1 for admitting dry powder cement into the bulk inlet chamber 19 located internally within the mixer housing 13 and then into the mixing chamber 6 which is also located internally within the mixer housing 13 . Adjacent to the dry bulk cement inlet 1 are two recirculation flow inlets 2 A and 2 B that both communicate with a recirculation manifold 10 that supplies recirculated cement slurry to five annular recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E located annularly around the inside of the mixing chamber 6 . Adjacent to the recirculation flow inlets 2 A and 2 B is a mix water inlet 11 that communicates with a mix water manifold 4 that supplies water to five annular water jets or jet orifices 5 A, 5 B, 5 C, 5 D and 5 E provided within the mixing chamber 6 downstream of the five annular recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E.
The water manifold 4 has a mix water adjustment output means consisting of a fixed orifice plate 14 containing the annular water jet orifices 5 A, 5 B, 5 C, 5 D and 5 E and a rotatable or movable water meter valve element or flow adjustment plate 8 with cut away openings 12 A, 12 B, 12 C, 12 D and 12 E therethrough. The movable flow adjustment plate 8 is provided with a handle 9 for rotating it in order to control the flow of mix water passing through the five annular water jets 5 A, 5 B, 5 C, 5 D and 5 E. At an outlet end 16 of the mixer 20 is an outlet 7 that discharges the cement mixture from the mixing chamber 6 of the mixer 20 . The details of all of these features will be described in more detail hereafter beginning at the inlet end 15 of the mixer 20 and moving toward the opposite outlet end 16 of the mixer 20 .
Beginning at the inlet end 15 of the mixer 20 , the mixer 20 is provided with a straight bulk cement inlet 1 for admitting dry powder cement into the mixing chamber 6 that is located internally within the mixer housing 13 . The straight bulk cement inlet 1 permits an unobstructed view inside and through both the bulk inlet chamber 19 and the mixing chamber 6 of the mixer 20 when piping that is normally connected with the inlet 1 is disconnected therefrom, as best illustrated in FIG. 1 . Also, this straight design allows for easier cleaning and inspection of both the bulk inlet chamber 19 and the mixing chamber 6 .
Referring now to FIGS. 1 , 2 and 3 , adjacent the dry bulk cement inlet 1 , the mixer 20 is provided with the two recirculation flow inlets 2 A and 2 B that both communicate with the recirculation manifold 10 . The recirculation manifold 10 supplies recirculated cement slurry to five annular recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E that are located around the inside of the mixing chamber 6 . Each recirculation jet or outlet 3 A, 3 B, 3 C, 3 D and 3 E is defined by two structures 17 and 18 within the mixer 20 . The first structure is the common wall 17 that separates the bulk inlet chamber 19 from the recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E, and the second structure is the common wall 18 that separates the recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E from the mix water manifold 4 . The recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E discharge at an angle A into the mixing chamber 6 .
Referring to FIGS. 3 and 4 , adjacent to the recirculation flow inlets 2 A and 2 B, the mixer 20 is provided with the mix water tangential inlet 11 . It is important that the inlet 11 be tangential relative to the water manifold 4 as water is then supplied tangentially to the water manifold 4 . The mix water inlet 11 communicates with the water manifold 4 that supplies water to the five annular water jet orifices 5 A, 5 B, 5 C, 5 D and 5 E provided within the mixing chamber 6 . By supplying the mix water tangentially to the water manifold 4 , the water is supplied so that it approaches the metering openings and metering slots 12 A-E and 5 A-E in a uniform manner, i.e. in the same direction, thus creating equal flow characteristics therethrough for all metering openings and metering slots 12 A-E and 5 A-E.
Referring to FIGS. 3 and 5 , the mix water manifold 4 is defined by three structures 18 , 13 and 8 within the mixer 20 . The first structure is the common wall 18 that separates the recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E from the mix water manifold 4 . The second structure is the outer mixer housing 13 for the mixer 20 , and the third structure is the rotatable flow adjustment plate 8 . Grooves 21 and 22 are provided in the surfaces that are adjacent to the rotatable water metering valve element 8 to accommodate pressure face seals 23 and 24 to contain water pressure within the mix water manifold 4 . A groove 25 is also provided in the fixed orifice plate 14 for a radial seal 26 to seal the fixed orifice plate 14 to the housing 13 of the mixer 20 so that fluid does not leak out of the mixing chamber 6 between the fixed orifice plate 14 and the housing 13 .
As shown in FIGS. 3 and 5 , the mixer 20 is provided with a mix water adjustment input means consist of the fixed orifice plate 14 which contains the annular water jet orifices 5 A, 5 B, 5 C, 5 D and 5 E and the rotatable or movable water meter valve element or flow adjustment plate 8 with cut away openings 12 A, 12 B, 12 C, 12 D and 12 E therethrough. The movable flow adjustment plate 8 is located adjacent to the fixed orifice plate 14 and between the water manifold 4 and the fixed orifice plate 14 . As shown in FIG. 3 , spacers 28 that are slightly larger in width than the rotatable flow adjustment plate 8 are provided surrounding the rotatable flow adjustment plate 8 to allow the flow adjustment plate 8 sufficient clearance between the wall of the water manifold 4 and the fixed orifice plate 14 so that the flow adjustment plate 8 can be rotated. The movable flow adjustment plate 8 is provided with a handle 9 for rotating the movable flow adjustment plate 8 relative to the fixed orifice plate 14 .
The fixed orifice plate 14 and the rotatable flow adjustment plate 8 cooperate to control the flow of water through the water jet orifices 5 A, 5 B, 5 C, 5 D and 5 E. The position of the movable flow adjustment plate 8 relative to the fixed orifice plate 14 controls the flow of water through the five annular water jets 5 A, 5 B, 5 C, 5 D and 5 E by more fully aligning the cut away openings 12 A, 12 B, 12 C, 12 D and 12 E of the movable flow adjustment plate 8 with the metering slots 5 A, 5 B, 5 C, 5 D and 5 E of the fixed orifice plate 14 , or alternately, by moving the cut away openings 12 A, 12 B, 12 C, 12 D and 12 E more completely out of alignment with the slots 5 A, 5 B, 5 C, 5 D and 5 E. As the movable flow adjustment plate 8 is rotated in a counter clockwise direction, as indicated by Arrow B in FIG. 4 , the cut away openings 12 A, 12 B, 12 C, 12 D and 12 E of the moveable flow adjustment plate 8 move so that they align longitudinally within the mixer 20 more completely with their corresponding annular water jet orifices 5 A, 5 B, 5 C, 5 D and 5 E provided in the fixed orifice plate 14 . This allows more water to pass from the water manifold 4 through the aligned portions of the openings 12 A, 12 B, 12 C, 12 D and 12 E and slots 5 A, 5 B, 5 C, 5 D and 5 E and into the mixing chamber 6 . Alternately, when the moveable flow adjustment plate 8 is rotated in a clockwise direction, as indicated by Arrow C in FIG. 4 , the cut away openings 12 A, 12 B, 12 C, 12 D and 12 E of the moveable flow adjustment plate 8 moves more out of alignment longitudinally within the mixer 20 with their corresponding annular water jet orifices 5 A, 5 B, 5 C, 5 D and 5 E. This allows less water to pass from the water manifold 4 through the movable flow adjustment plates and fixed orifice plates 8 and 14 and out into the mixing chamber 6 . The water jets 5 A, 5 B, 5 C, 5 D and 5 E discharge at an angle D into the mixing chamber 6 .
The five annular recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E are located longitudinally upstream within the mixing chamber 6 relative to the five annular water jet 5 A, 5 B, 5 C, 5 D and 5 E so that the recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E discharge into the mixing chamber 6 upstream of the discharge from the water jets 5 A, 5 B, 5 C, 5 D and 5 E. The evenly spaced water jets 5 A, 5 B, 5 C, 5 D and 5 E deliver mix water non-axially to the mixing chamber 6 downstream of where the evenly spaced recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E deliver recirculation flow non-axially to the mixing chamber 6 . This arrangement is important for several reasons. The location of the water jets 5 A, 5 B, 5 C, 5 D and 5 E tends to intersect with and further mix the slurry which was introduced upstream in the mixing chamber 6 , thus enhancing mixing. Existing technology with annular adjustable orifices alternate rather than intersect the discharge from the recirculation jet flow. Also, the location of the water jets 5 A, 5 B, 5 C, 5 D and 5 E downstream of the recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E also tends to protect the internal surfaces of the mixing chamber 6 from abrasion by the sand and grit contained in the recirculated cement slurry flowing out of the recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E or by sand contained in unclean water flowing out of the water jets 5 A, 5 B, 5 C, 5 D and 5 E when the water source is unclean. Referring to FIGS. 1 , 3 and 4 , the five recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E are arranged in such a way as to create a “star” arrangement in the inner casing 17 which is the common wall between the bulk inlet chamber 19 and the five recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E. By having the inner casing 17 in a “star” arrangement and extending inside and inwardly beyond the normal parallel walled casing ID, as indicated by numeral 27 in the drawings, this helps to reshape the configuration of the dry bulk powder into a “star” shape as it flows through the bulk inlet chamber 19 and enters the mixing chamber 6 before it is hit with flow from the recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E. The resulting “star” shape of the flow of powder tends to assist in splitting or breaking up the flow of dry bulk cement coming through the casing ID, thus enhancing the wetability of the bulk cement.
Finally, as shown in FIGS. 2 and 3 , the outlet 7 for the mixer 20 is provided at the outlet end 16 of the mixer 20 . The mixture of cement leaves the mixing chamber 6 of the mixer 20 through the outlet 7 .
Although the invention has been described as having five recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E and five water jets 5 A, 5 B, 5 C, 5 D and 5 E, the invention is not so limited. In fact the invention can be provided with only three recirculation jets and only three water jets, or alternately, with seven of each. The invention can alternately be provided with even numbers of both recirculation jets and water jets. The important thing is that the water jets are located downstream in the mixing chamber 6 from the associated recirculation jets so that the flow from the water jet intersects with the flow from its associated recirculation jet. The preferred arrangement is where there is the same number of recirculation jets as water jets and where there are odd numbers of each type of jets, i.e. three, five, seven, etc. of each of the recirculation jets and water jets. For example, a smaller mixer might employ only three recirculation jets and three water jets, while a larger mixer might employ seven recirculation jets and seven water jets.
Operation
Dry bulk cement powder is pneumatically blown straight into the mixer 20 at straight dry bulk cement inlet 1 . As the dry bulk cement passes through the mixer's internal bulk inlet chamber 19 and subsequently into the mixing chamber 6 , it is intercepted by flow of recirculated cement slurry flowing from the five recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E. The interception of the dry bulk cement by the recirculated slurry is the first step in wetting the cement powder. A short distance later (milliseconds in time) and downstream within the mixing chamber 6 , the five water jets 5 A, 5 B, 5 C, 5 D and 5 E intersect the partially wetted cement. The mixing energy imparted by the recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E and the water jets 5 A, 5 B, 5 C, 5 D and 5 E is very high. The high energy of all ten jets, i.e. five recirculation jets 3 A, 3 B, 3 C, 3 D and 3 E and five water jets 5 A, 5 B, 5 C, 5 D and 5 E, creates a well mixed slurry where all particles are wetted. The recirculation rate is constant and typically 20 bbl/min. The water flow is adjusted by rotating the flow adjustment plate 8 . FIG. 4 shows the flow adjustment plate 8 with the cut away openings 12 A, 12 B, 12 C, 12 D and 12 E and metering slots 5 A, 5 B, 5 C, 5 D and 5 E. As the flow adjustment plate 8 is moved counter clockwise, i.e. in the direction indicated by Arrow B, the metering slots 5 A, 5 B, 5 C, 5 D and 5 E are uncovered so that liquid flows therethrough. The flow rate is approximately proportional to the rotation of the flow adjustment plate 8 . Typical pressure is 125 psi and maximum flow might be in the range of 10 bbl/min. The thoroughly wetted and mixed cement slurry exits the mixing chamber 13 via the outlet 7 and flows to the mixing tank, as previously described above for a typical equipment arrangement.
Although the invention has been described for use in mixing cement for oil or gas wells, the invention is not so limited and can be used to mix a variety of bulk powders into a solution. Also, the usage of this invention is not limited to the oil and gas industry, but could be used in other industries where dry bulk powders must be mixed into a solution, such as for example the food preparation industry.
While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for the purposes of exemplification, but is to be limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element thereof is entitled.
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A cement mixing method for mixing cement used in cementing oil wells casing and the mixer used in that method. The mixer employs a straight bulk cement inlet, five annular recirculation jets and five annular water jet orifices located downstream of the recirculation jets so that all of the jets discharge at an angle towards the mixing chamber and the discharge from the water jet orifices intersects with the flow from the recirculation jets. This five jet, intersecting flow design allows for more thorough wetting of the cement powder with a smaller, lighter, less expensive and more durable mixer that is less inclined to foul and easier to clean.
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This application is a continuation of application Ser. No. 288,823, filed Dec. 23, 1988, now abandoned.
DETAILED DESCRIPTION OF THE INVENTION
Background of the Invention
1. Field of the Invention
This invention relates to a shaft sealer which seals a shaft hole by retaining a magnetic fluid between a magnetic shaft and a magnetic fluid retainer located around the circumference of the shaft, and more particularly to a shaft sealer employing a magnetic fluid retainer which is improved in construction to utilize the flux of the magnetic circuit effectively for retention of the magnetic fluid.
2. Description of Background
Shaft sealers using a magnetic fluid are increasingly used in various fields including the fields of vacuum devices and magnetic disk drives. For instance, as shown in FIG. 3, a shaft sealer using a magnetic fluid includes a housing 4 having a shaft hole 2 of a diameter sufficiently larger than the outer diameter of a magnetic shaft 1 and a stepped portion 3 formed at least at one end of the shaft hole 2 and an inner periphery of a diameter larger than that of the shaft hole 2, and a magnetic fluid retaining member 7 fittingly mounted in the stepped portion 3 of the housing 4 with a non-magnetic member 6. A magnetic fluid 8 is retained in the gap space between the rotational shaft 1 and the magnetic fluid retaining member 7 to form a seal around the circumference of the rotational shaft 1. Recently special attention is paid to the seal which is maintained by the magnetic fluid in this manner because the seal can be maintained free of the problem of friction as experienced with the ordinary solid seal members.
In case of the conventional shaft sealer as described above, however, the magnetic fluid retaining member 7 normally has a pair of annular magnetic yokes 7b of the same outer diameter securely fixed to the axially opposite sides of an annular magnet 7a to generate a magnetic field for retaining the magnetic fluid in the gap space which is formed between the magnetic fluid retaining member 7 and the magnetic shaft 1. The magnetic flux which is produced by the magnet mainly takes the path of magnet 7a--one yoke 7b--one gap portion--rotational shaft 1--the other gap portion--the other yoke 7b--magnet 7a, acting effectively for the retention of the magnetic fluid.
In the retaining member shown in FIG. 3, a nonmagnetic member 6 of a synthetic resin material or the like is interposed between the annular magnetic fluid retaining member 7 and the axial bottom surface 3a and the inner peripheral surface 3b of the stepped portion 3 in the housing 4. In a case where the housing 4 is formed of a magnetic material, this arrangement is essential to prevent leaks of the magnetic flux to the housing 4 from the outer periphery of the magnetic fluid retaining member 7.
In a case where the non-magnetic member 6 of a thickness suitable for forming a magnetically sufficient gap space is absent, it becomes difficult to prevent the leaks of the magnetic flux from the yokes to a sufficient degree, resulting in weakening of the magnetic force at the inner periphery of the shaft hole 5 of the retaining member 7 as well as weakening of the force for retaining the magnetic fluid 8, making it difficult to realize a practically useful magnetic fluid seal. In addition, the magnetic flux which passes through the magnetic housing has possibilities of imposing adverse effects on other devices, for example, causing errors to a recording medium of a magnetic disk drive.
Nevertheless, it is not desirable to locate the non-magnetic member hermetically between the magnetic fluid retaining member and the housing since it increases the number of parts and is therefore disadvantageous from the standpoint of industrial fabrication of the shaft sealers. The plastics or a relatively soft material which is normally used for the non-magnetic member involves the problem of eccentricity in the assembling process of the magnetic fluid retaining member. For example, when assembling a shaft sealer using a magnetic fluid, if the gap space between the magnetic fluid retaining member and the shaft is not uniform, the magnetic field is weakened at a broader gap portion than at a narrower gap portion, resulting in uneven magnetic fluid retention force and lowered pressure resistance.
SUMMARY OF THE INVENTION
With the foregoing in view, the present invention has as its object the provision of a shaft sealer using a magnetic fluid, which is constructed in such a manner as to utilize more effectively the magnetic force of the magnetic fluid retaining member. It is also an object of the invention to provide a shaft sealer of the sort mentioned above, which is easy to manufacture.
According to the invention, there is provided a magnetic fluid retainer, comprising: at least one pair of yokes each having a shaft hole for passing therethrough a magnetic shaft; and an axially magnetized permanent magnet having a hole of a diameter slightly larger than the shaft hole in the yokes and gripped between the yokes substantially in concentric relation therewith; one of the yokes having an outer diameter smaller than that of the other yoke.
According to another aspect of the invention, there is provided a shaft sealer, comprising: a magnetic housing having a stepped portion at least at one end of a shaft receiving hole of a diameter sufficiently larger than the outer diameter of a shaft to be fitted therein; a magnetic fluid retainer having a shaft hole for passing therethrough a magnetic shaft and fittingly mounted in the stepped portion of the housing; and a magnetic fluid retained between the shaft and the magnetic fluid retainer; the magnetic fluid retainer being constituted by at least one pair of yokes and a magnet gripped between the yokes, one of the yokes having a smaller outer diameter than the other to form a broader gap space between the yoke of the smaller outer diameter and the inner periphery of the stepped portion of the housing than between the yoke of the greater outer diameter and the stepped portion of the housing.
According to the present invention, by the use of a magnet with an outer diameter smaller than the yoke of the larger outer diameter and greater than the yoke of the smaller outer diameter, it becomes possible to realize a magnetic fluid retainer with more preferable characteristics and a shaft sealer incorporating such magnetic fluid retainer.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a fragmentary sectional view of major components of a shaft sealer according to the invention;
FIG. 2 is a fragmentary sectional view of major components in another embodiment of the invention;
FIG. 3 is a fragmentary sectional view of major components of a conventional shaft sealer;
FIG. 4 is a magnetic flux flow chart showing the results of magnetic analysis by computer simulation of the conventional magnetic fluid retainer mounted on magnetic housing;
FIGS. 5, 7 and 9 are magnetic flux flow charts showing the re of magnetic analyses by computer simulation of magnetic fluid retainers of the invention, mounted on magnetic housing;
FIGS. 6 and 8 are diagrams of the amount of magnetic fluid injection versus pressure resistance in Examples of the invention and Comparative Example.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The magnetic fluid retainer according to the present invention is formed by fixing magnetic yokes to the axially opposite end faces of a magnet, one of the yokes being formed in a smaller outer diameter than the other yoke to provide a magnetic gap between the circumferential surface of the smaller yoke and the inner periphery of the stepped portion of the housing of magnetic material.
In the present invention, even a magnetic gap smaller than 0.1 mm is useful if the magnetic reluctance can be increased to a substantial degree. However, in order to secure a sufficient magnetic reluctance stably in consideration of the problem of machining accuracy it is preferred that the afore-mentioned magnetic gap be greater than 0.2 mm, more preferably, greater than 0.5 mm to ensure a sufficient magnetic reluctance practically free of problems. Further, in the present invention, the outer diameter of the magnet which is gripped between the yokes can be arbitrarily selected from the range between the outer diameters of the larger and smaller yokes. A magnet with a larger outer diameter (a larger volume) can produce a stronger magnetic field in the gap formed between the yokes and the rotational shaft, but on the other hand a magnet with a smaller outer diameter has an advantage that the magnetic fluid retainer can be constructed in a smaller and more compact form to provide a shaft sealer of reduced size and weight.
In the magnetic fluid shaft sealer the invention, one of the yokes which constitute the magnetic fluid retainer is smaller than the other yoke in outer diameter to provide a gap of a certain breadth between its outer periphery and the inner periphery of the magnetic housing, so that, as compared with the primary magnetic circuit at the inner periphery of the magnet (the primary path for sealing the shaft with the magnetic fluid, i.e., the path of the magnet--one yoke (the smaller yoke)--one gap portion--the rotational shaft--the other gap portion--the other yoke (the larger yoke)--the magnet), the reluctance of the magnetic circuit at the outer periphery of the magnet (the path of the magnet--the smaller yoke (one yoke)--the magnetic gap--the magnetic housing--the larger yoke (the other yoke) the magnet) becomes greater to suppress leaks of the magnetic flux. Accordingly, the magnetic force of the magnetic fluid retainer is strengthened at the magnetic fluid retaining portion (in the gap portion formed between the inner peripheral surfaces of the shaft holes in the yokes and the rotational shaft), without giving adverse effects on other neighboring devices by suppression of the magnetic flux leaks through the magnetic housing.
Hereafter, the invention is described more particularly with examples.
EXAMPLE 1
Referring to FIG. 1, there is shown in a fragmentary sectional view an embodiment of the shaft sealer according to the present invention, wherein indicated at 1 is a rotational shaft of a magnetic material which shaft is fitted in a through hole 2 of a housing 4 of magnetic material with a stepped portion 3 at one end of the through hole 2. Fitted in the stepped portion 3 is a magnetic fluid retainer 7 which is constituted by a pair of yokes 7b 1 and 7b 2 each with a shaft hole 5 for passing therethrough the shaft 1 and a magnet 7a which is fixedly gripped between the yokes 7b 1 and 7b 2 . The magnet 7a is provided with a hole of a diameter larger than the shaft holes in the yokes, positioned substantially in concentric relation with the yokes, and magnetized in the axial direction.
Of the above-mentioned paired yokes, one yoke 7b 1 is formed to have a smaller outer diameter than the other yoke 7b 2 which is abuttingly secured to the bottom surface 3a and inner peripheral surface 3b of the stepped portion 3. A magnetic fluid 8 is retained between the rotational shaft 1 and the inner peripheral surfaces of the shaft holes in the respective yokes of the magnetic fluid retainer 7. On the other hand, a magnetic gap 9 is substantially formed between the circumferential surface of the yoke 7b 1 of the smaller outer diameter and the inner peripheral surface 3b of the stepped portion 3 to have a large reluctance thereacross. Accordingly, as compared with the primary magnetic circuit which acts on the magnetic fluid for the shaft sealing, namely, the path of the magnet 7a--the smaller yoke 7b 1 --the gap portion--the rotational shaft 1--the gap portion--the larger yoke 7b 2 --the magnet 7a, the reluctance is increased with regard to the magnetic circuit of the magnet 7a--the smaller yoke 7b 1 --the magnetic gap 9--the magnetic housing 4--the larger yoke 7b 2 --the magnet 7a, relatively suppressing the leaks of the magnetic flux to increase the magnetic force at the magnetic fluid retaining portions for higher shaft sealing effects.
Since the magnet 7a is magnetized in an axial direction (thickness direction), magnetic flux from the magnet 7a is emitted perpendicularly from the end surface of the magnet and comes to the yoke or housing. Accordingly, although the outside diameter of the magnet 7a is shown to be almost the same as the outside diameter of the larger yoke 7b2 in FIG. 1, the outer diameter of the magnet 7a may be the same as the outside diameter of the smaller yoke to cause the similar advantage of magnetic gap between the housing and the smaller yoke.
Annular ferrite bonded magnets with dimensions of 16.5 mm in outer diameter, 9.4 mm in inner diameter and 0.6 mm in thickness were prepared to serve as the magnet 7a. As the yoke 7b 2 of larger outer diameter, annular yoke plates with dimensions of 16.5 mm in outer diameter, 8.4 mm in inner diameter and 0.2 mm in thickness were prepared from magnetic stainless steel. Further, as the yoke 7b 1 of the smaller outer diameter, three kinds of yoke plates with outer diameters as shown in Table 1 below, an inner diameter of 8.4 mm and a thickness of 0.2 mm were prepared from magnetic stainless steel.
TABLE 1______________________________________ Pressure resistance (mm H.sub.2 O) Mounted in Outer Diam. Non- Mounted in Specimen of Smaller magnetic magneticStatus No. Yoke (mm) Housing Housing______________________________________Compara- 1 16.5 242 65tiveExampleInvention 2 15.5 203 190 3 14.5 145 252 4 13.5 102 140______________________________________
Then the respective yokes were adhered to the opposite sides of each one of the above-mentioned bonded magnet concentrically by the use of a cyanoacrylate-base adhesive to prepare the specimens No. 2 to 4 of the magnetic fluid retainer according to the invention.
Each one of these magnetic fluid retainers was fitted on a 8 mm shaft of magnetic material and mounted in a housing of a magnetic material. Thereafter, 7.5 microliters of a magnetic fluid was injected to and retained in the gap space between the magnetic fluid retainer and the shaft to form a shaft sealer of the construction as shown in FIG. 1. The results of measurement of pressure resistances of the respective magnetic fluid retainers are shown in Table 1. The pressure resistance indicates the value of the pressure (the maximum pressure) immediately before an abrupt pressure drop caused by erruption of the magnetic fluid seal in a sealed vessel which was pressurized at a speed of 50 mmH 2 O/min by air injection.
For the purpose of comparison, measurements were also made of the pressure resistances of the above-described magnetic fluid retainers which were mounted on non-magnetic housings, as shown in Table 1. Further, as a Comparative Example, a magnetic fluid retainer with yokes of same outer diameters (Specimen No. 1) was studied, obtaining results as shown also in Table 1.
As clear from Table 1, the magnetic fluid retainers according to the invention show a higher pressure resistance when mounted on a magnetic housing rather than on a non-magnetic housing.
It is also seen therefrom that, when the magnetic fluid retainer of the invention is mounted on a magnetic housing with appropriate designing (e.g., Specimen No. 3), it exhibits superior characteristics in pressure resistance (252mmH 2 O) as compared with the conventional counterpart, namely, the pressure resistance (242mmH 2 O) of the Comparative Example. This is considered that, in the magnetic fluid retainer of the invention, the existence of a gap of a width greater than 0.5 mm between the yokes and the housing increases the reluctance at that part even when it is mounted on a magnetic housing, suppressing the magnetic flux portion which otherwise tends to return through the housing. As a result, it becomes possible to increase relatively the amount of the magnetic flux to the magnetic fluid retaining gap portions between the shaft and the fluid retainer.
On the other hand, the magnetic fluid retainer with yokes of same outer diameters (Specimen No. 1), which is given as Comparative Example, exhibits a high pressure resistance when mounted on a non-magnetic housing. However, when mounted on a magnetic housing, its pressure resistance drops considerably to a level which is unacceptable for practical applications. This is considered to be attributable to a marked reduction in the amount of the magnetic flux which reaches the magnetic fluid retaining gap portion between the shaft and the magnetic fluid retainer, since when mounted on a magnetic housing the major part of the magnetic flux produced by the magnet is allowed to return through the housing.
These phenomena were analyzed by magnetic field analysis simulations using a computer. The results in exemplary cases are shown in FIGS. 4 and 5. More specifically, as clear from FIG. 4, the magnetic flux 10 produced by the magnet 7a of the shaft sealer of the conventional construction mostly flows toward the magnetic housing 4 through the yoke, so that the flux to the magnetic fluid retaining gap portion 5 (i.e., the gap space formed between the rotational shaft 1 and the yoke 7b) is reduced to an extremely small amount.
In contrast, in case of Specimen No. 3 according to the invention, the magnetic flux 10 produced by the magnet 7a mainly flows toward the shaft 1 through the smaller yoke 7b 1 as shown in FIG. 5, with a larger amount of magnetic flux passing through the magnetic fluid retaining gap 5. It will be seen that, in this case, the flow of magnetic flux is blocked at a broad gap space which is formed between the smaller yoke 7b 1 and the inner periphery 3b of the stepped portion which has a diameter almost same as the outer diameter of the larger yoke 7b 2 .
Plotted in FIG. 6 are variations in pressure resistance of the respective fluid retainers of Table 1, which were mounted on a magnetic housing and injected with a varying amount of magnetic fluid. It will be seen from FIG. 6 that, although there is an unstable zone wherein pressure resistance comes down depending on the amount of magnetic fluid injection, the pressure resistance with more amount of magnetic fluid was improved in proportion to the amount of magnetic fluid injection. As clear therefrom, Specimens Nos. 2, 3 and 4,representing the magnetic fluid retainer of the invention, excelled Specimen No. 1 of the conventional magnetic fluid retainer, exhibiting a higher pressure resistance for any amount of magnetic fluid injection.
EXAMPLE 2
As another example, the size of the magnet in the shaft sealer construction shown in FIG. 1 was varied.
To serve as the magnet 7, there were prepared annular ferrite bonded magnets with outer diameters as shown in Table 2, an inner diameter of 9.4 mm and a thickness of 0.6 mm. As the yoke of larger outer diameter, there were prepared annular yokes of 16.5 mm in outer diameter, 8.4 mm in inner diameter and 0.2 mm in thickness.
As the smaller yoke, there were prepared annular yokes with outer diameters as shown in Table 2, an inner diameter of 8.4 mm and a thickness of 0.2 mm.
TABLE 2______________________________________ Pressure Resistance Magnet Smaller Mounted in Speci- Outer Outer Non- Mounted in men Diam. Diam. magnetic magneticStatus No. (mm) (mm) housing housing______________________________________Compa- 1 16.5 16.5 242 65rativeEx.Inven- 5 15.5 15.5 182 163tion 6 14.5 14.5 132 205 7 13.5 13.5 95 128______________________________________ Note: Outer Diameters of larger yokes were all 16.5 mm.
Next, the respective yokes were secured to the opposite axial end faces of the magnet substantially in concentric relation by the use of a cyanoacrylate-base adhesive to obtain magnetic fluid retainers according to the invention (Specimen Nos. 5 to 7).
After fitting a shaft of 8 mm, each one of these magnetic fluid retainers was mounted on a magnetic housing, measuring the pressure resistance of the magnetic fluid which was supplied to the gap portion between the magnetic fluid retainer and the shaft in an amount of 7.5 microliters. The results are shown in Table 2.
As stated in Example 1, the magnetic fluid retainer of Comparative Example exhibits a high pressure resistance when mounted on a non-magnetic housing, but its pressure resistance drops markedly to a practically unusable level when mounted on a magnetic housing since the magnetic flux of the magnetic fluid retainer tends to return through the housing, reducing the amount of the magnetic flux to the magnetic fluid retaining gap portion between the shaft and the magnetic fluid retainer.
Conversely, in case of the magnetic fluid retainer according to the invention, the drop in pressure resistance is very small even when the retainer is mounted on a magnetic housing.
This is because, even when the magnetic fluid retainer of the invention is mounted on a magnetic housing, the gap space of 0.5 mm or larger which exists between a yoke and the housing increases the reluctance at that portion, suppressing the return through the housing of the magnetic flux produced by the magnet. Consequently, it becomes possible to increase relatively the amount of magnetic flux to the magnetic fluid retaining gap portion between the shaft and the magnetic fluid retainer, permitting to realize a shaft sealer of excellent characteristics.
These phenomena are clearly seen in the results of computerized magnetic field analysis shown in FIG. 7. That is, in FIG. 7, the magnetic flux 10 produced by the magnet 7a mostly flows toward the shaft 1 through the yoke 7b 1 , with a large amount of magnetic flux passing across the magnetic fluid retaining gap portion 5. This owes to the provision of the large magnetic gap which is formed between the yoke 7b 1 of smaller outer diameter and the inner periphery 3b of the stepped portion substantially equal to the outer diameter of the larger yoke 7b 2 , the gap increasing the reluctance at that portion to block the flow of magnetic flux.
Shown in FIG. 8 are variations in pressure resistance of the magnetic fluid retainers of Table 2, which were mounted in a magnetic housing and supplied with a varying amount of magnetic fluid. As seen in FIG. 8, Specimens Nos. 5 to 7 of the magnetic fluid retainer according to the invention all show a higher pressure resistance than Specimen No. 1 of the conventional magnetic fluid retainer. Especially, Specimen No. 7 according to the invention exhibits a pressure resistance equivalent to or higher than that of Comparative Example even though its magnet is about half in volume, indicating that the magnetic fluid retainer of the present invention is extremely effective for attaining reductions in size and improvements in performance of the shaft sealer.
EXAMPLE 3
Now a further example of the invention is described with reference to FIG. 2.
In this example, of the two yokes 7b 1 and 7b 2 on the opposite sides of the bond magnet 7a, the yoke 7b 1 which is abutted against the bottom surface 3a of the stepped portion 3 in the housing 4 has a smaller outer diameter, and a non-magnetic member 6 of a synthetic resin material or the like is interposed between the yoke 7b 1 and the stepped portion 3, forming a substantial magnetic gap between the yoke 7b 1 and the magnetic housing 4 to prevent leaks of magnetic flux to the housing 4 from circumferential portions of the magnetic fluid retainer 2. The yoke 7b 2 of larger outer diameter, which is located on the opposite side of the magnet has its outer periphery fitted in the stepped portion 3 of the magnetic housing 4 and is fixedly secured to the inner peripheral surface 3b of the housing. In the same manner as in Example 1, a magnetic fluid 3 is retained between the shaft 1 and yokes 7b and 7b 2 .
FIG. 2 shows that the outside diameter of the magnet 7a is smaller than the outside diameter of the smaller yoke, but the outside diameter of the magnet may be larger than the outside diameter of the smaller yoke or the same as the outside diameter of the larger yoke to provide the advantage of this invention as discussed in Example 1.
Although the non-magnetic member 6 is extended as far as the outer periphery of the yoke 7b l in FIG. 2, it is not necessarily required to be extended to that portion. In case of the sealer construction incorporating a non-magnetic member between the smaller yoke and the bottom surface of the stepped portion as shown in FIG. 2, the centering is effected through the large-diameter yoke without relying on the smaller-diameter yoke, so that there is an advantage that deformation of the non-magnetic member is unlikely to cause eccentric deviation.
Annular ferrite bonded magnets with dimensions of 16.5 mm in outer diameter, 9.4 mm in inner diameter and 0.6 mm in thickness were prepared to serve as the magnet 7a. Annular yoke plates with dimensions of 16.5 mm in outer diameter, 8.4 mm in inner diameter and 0.2 mm in thickness were prepared from magnetic stainless steel to serve as the large-diameter yoke 7b 2 . Further, three kinds of annular yoke plates with outer diameters as shown in Table 3 below, an inner diameter of 8.4 mm and a thickness of 0.2 mm were prepared as the small-diameter yoke 7b 1 .
Table 3 also presents the pressure resistances measured for the Specimen No. 8 construction for both non-magnetic and magnetic housings, in comparison with the corresponding values of the Comparative Example described earlier. FIG. 9 shows a computer simulation of the magnetic field surrounding the Specimen No. 8 construction.
TABLE 3______________________________________ Pressure resistance (mm H.sub.2 O) Mounted in Outer Diam. Non- Mounted in Specimen of Smaller magnetic magneticStatus No. Yoke (mm) Housing Housing______________________________________Compara- 1 16.5 242 65tiveExampleInvention 8 14.5 132 252______________________________________
Although the foregoing examples employs bonded magnets which are formed by mixing ferrite magnet powder, samarium cobalt magnet powder or neodymium iron boron magnet powder into nylon followed by magnetization. However, sintered or other types of magnets are applicable in the present invention in place of the bonded magnets.
It will be appreciated from the foregoing description that, in the magnetic fluid retainer according to the present invention or the shaft sealer incorporating such retainer, one of the yokes on the opposite sides of the magnet is formed in a reduced outer diameter to provide a spacing between the small-diameter yoke and the magnetic housing to act as a reluctance preventing escape of the magnetic flux to the outside. It manifests excellent effects especially when applied to a shaft which is passed through part of a magnetic housing. When designed appropriately, the magnetic force at the inner periphery of the shaft hole of the magnetic fluid retainer is sufficiently strong, retaining the magnetic fluid securely with a force excelling even the magnetic force of the conventional magnetic fluid retainer which is mounted in a non-magnetic housing. Besides, adjacent devices are free from the adverse effects of the magnetic flux which would otherwise leak to the outside through the magnetic housing. Moreover, in addition to an economical advantage that the amounts of the materials to be used for the yokes and magnet can be reduced, the invention contributes to the reduction of weight of the shaft sealer.
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Apparatus for sealing a magnetic shaft includes a magnetic housing having a throughbore with a stepped enlargement at one end, a pair of annular disk-shaped yokes spaced apart by an axially magnetized permanent magnet positioned in the stepped enlargement and surrounding the shaft, and magnetic fluid in the gaps between the yokes and the shaft. The outside diameter of one yoke is spaced from the magnetic housing and is smaller than the outside diameter of the other yoke, while the larger yoke abuts the magnetic housing at its outside diameter. A plastic, non-magnetic member can separate the smaller diameter yoke from the magnetic housing.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a golf club head and, more particularly, to a golf club head having a removable weight.
2. Description of Related Art
U.S. Pat. No. 6,773,360 discloses a golf club head having a weight assembly removably mounted in a recess on a sole of a main body of the golf club head. The recess bottom defines a threaded opening. The weight assembly includes a mass element received in the recess, a screw, and a retaining element. The mass element includes a recess for receiving the retaining element. The screw is extended through an aperture of the mass element and threadedly engaged with the threaded opening of the recess bottom of the main body. The retaining element has outer threads for engaging with internal threads in the recess of the mass element to retain the screw head in the recess of the main body. The weight assembly allows adjustment in the center of gravity of the golf club head to improve swing stability for the golfer.
However, when striking a golf ball with the ball striking face of the golf club head, the vibration generated is imparted to the screw and thus causes loosening or even disengagement of the screw and the mass element. The engaging reliability and assembly between the mass element and the main body deteriorate.
OBJECTS OF THE INVENTION
The primary object of the present invention is to provide a golf club head having a removable weight with improved engaging reliability while allowing adjustment in the center of gravity of the golf club head.
Another object of the present invention is to provide a golf club head having a removable weight that allows easy assembly and easy replacement of the weight.
SUMMARY OF THE INVENTION
To achieve the aforementioned objects, the present invention provides a golf club head including a body; a retaining element removably mounted to the body, with the retaining element including a main body and an annular wall extending from a side of the main body of the retaining element, with the annular wall defining a compartment; a weight received in the compartment of the retaining element and retained to the body of the golf club head by the retaining element; and a vibration absorbing washer received in the compartment of the retaining element and mounted to the weight, with the vibration absorbing washer absorbing vibration during swing, thereby enhancing assembling reliability of the weight.
In an example, the body of the golf club head includes a sole having a recess for receiving the retaining element. In another example, the body of the golf club head includes a skirt having a recess for receiving the retaining element.
Preferably, a peripheral wall defining the recess includes inner threading, and the annular wall of the retaining element includes outer threading for threadedly engaging with the inner threading.
Preferably, a bottom wall defining the recess includes a positioning hole. The weight includes a flange on an outer periphery thereof. The flange of the weight has a diameter greater than that of the positioning hole. An end of the weight extends through the positioning hole of the bottom wall. The vibration absorbing washer is mounted around the weight and sandwiched between the flange and the bottom wall defining the recess.
Preferably, a second vibration absorbing washer is mounted around the weight and sandwiched between the flange and the main body of the retaining element.
Preferably, the main body of the retaining element includes a positioning hole through which the other end of the weight extends.
Preferably, the main body of the retaining element further includes at least two tool coupling holes in a side thereof for assembling or detaching the retaining element to or from the recess.
The weight may be made of metal powders and elastomeric resin. The vibration absorbing washer may be made of rubber or polyurethane.
Other objects, advantages and novel features of this invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a first embodiment of a golf club head having a removable weight in accordance with the present invention;
FIG. 2 is an exploded sectional view of a portion of the golf club head of FIG. 1 ;
FIG. 3 is a sectional view of the golf club head of FIG. 3 after assembly;
FIG. 4 is an exploded perspective view of a second embodiment of the golf club head in accordance with the present invention; and
FIG. 5 is an exploded perspective view of a third embodiment of the golf club head in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2 , a first embodiment of a golf club head in accordance with the present invention includes a body 1 , a weight 2 , at least one vibration absorbing washer 3 (two in this embodiment), and a retaining element 4 . In this embodiment, the golf club head is of wood type that can be made of a single material by integral formation or composed of a plurality of parts. The body 1 includes a striking face 11 , a toe 12 , a heel 13 , a crown (not shown), a sole 14 , and a skirt 15 . A recess 16 is defined in the sole 14 and includes inner threading 160 in a peripheral wall thereof. A bottom wall defining the recess 16 includes a positioning hole 161 .
Still referring to FIGS. 1 and 2 , the weight 2 of the first embodiment is preferably cylindrical or polygonal in section. The weight 2 includes a flange 20 on a part of an outer periphery thereof and between two ends of the weight 2 . The flange 20 has a diameter greater than that of the positioning hole 161 of the recess 16 . Thus, the weight 2 is prevented from falling into an interior of the body 1 after an end of the weight 2 is extended through the positioning hole 161 of the recess 16 . The weight 2 is made of a material having a larger specific weight, such as W—Fe—Ni alloy, carbon steel, low-carbon steel, stainless steel, alloy steel, low-alloy steel, martensite steel, cast iron, nickel-based alloy or non-metal materials. The specific weight of the weight 2 can be greater or smaller than that of the body 1 to provide different weighting effects. Furthermore, the size and material for the weight 2 can be selected to adjust the center of gravity of the body 1 . Furthermore, the material of the weight 2 may include metal powders and elastomeric resin to provide vibration absorbing effect. It can be however appreciated that the weight 2 of the present invention can be made of any conventional metal or non-metal materials for making golf club heads.
Still referring to FIGS. 1 and 2 , the vibration absorbing washers 3 are preferably made of elastomeric materials such as rubber or polyurethane. Each vibration absorbing washer 3 includes an assembling hole 30 in a center thereof and mounted to and abutting against a side of the flange 20 . Preferably, the vibration absorbing washers 3 are respectively mounted to two sides of the flange 20 to enhance the vibration absorbing effect.
Still referring to FIGS. 1 and 2 , the retaining element 4 of the first embodiment includes a main body 40 having a positioning hole 401 in a center thereof for the weight 2 to protrude, and an user can conveniently check and choose a suitable weight 2 . At least two coupling holes 400 are defined in a side of the main body 40 for coupling with a tool (not shown) for the purposes of assembling or detaching the retaining element 40 . An annular wall 41 extends from the other side of the main body of the retaining element 40 and defines a compartment 410 for receiving the other end of the weight 2 and the vibration absorbing washers 3 . An outer thread 411 is formed on an outer periphery of the annular wall 41 for threadedly engaging with the inner thread 160 of the recess 16 .
With reference to FIG. 3 , in assembly, the vibration absorbing washers 3 are mounted around the weight 2 and respectively abut against two sides of the flange 20 of the weight 2 which is then placed into the compartment 410 of the retaining element 4 , with one of the vibration absorbing washers 3 securely sandwiched between the flange 20 and the retaining element 4 , and with an end (the upper one in FIGS. 2 and 3 ) of the weight 2 extending beyond the positioning hole 401 of the retaining element 4 . The other end (the lower one in FIGS. 2 and 3 ) of the weight 2 is then extended through the positioning hole 161 of the recess 16 . A tool is coupled with the tool coupling holes 400 of the retaining element 4 to threadedly engage the outer threading 411 of the retaining element 4 with the inner thread 160 of the recess 16 until the other vibration absorbing washer 3 is securely sandwiched between the bottom wall of the recess 16 and the flange 20 of the weight 2 . The vibration absorbing washers 3 are capable of directly absorbing and, hence, reducing the striking stress imparted to the golf club head. The vibration absorbing effect of the body 1 is, thus, enhanced. By providing the vibration absorbing washers 3 and the retaining element 4 , the adjusting flexibility, assembling reliability, and replacement convenience of the weight 2 are greatly improved. Furthermore, the engaging reliability between the weight 2 and the body 1 is enhanced.
FIG. 4 shows a second embodiment of the present invention in which the body 1 is also of wood type. In this embodiment, a plurality of recesses 16 are defined in the skirt 15 of the body 1 . The recesses 16 may be cylindrical or of any suitable shapes and extend inward into the interior of the body 1 . At least one of the recesses 16 is defined in a rear portion of the skirt 15 . A weight 2 is mounted in each recess 16 by a retaining element 4 , allowing adjustment of the center of gravity of the golf club head to a position adjacent to the skirt 15 and enhancing the engaging reliability between the weight 2 and the body 1 while improving the adjusting flexibility, assembling reliability, and replacement convenience of the weight 2 .
FIG. 5 shows a third embodiment of the present invention in which the body 1 is of iron type including a ball striking portion (not shown), a toe 12 , a heel 13 , a blade 17 , and a sole 14 . In this embodiment, a plurality of recesses 16 are defined in the sole 14 of the body 1 . The recesses 16 may be cylindrical or of any suitable shapes and extend inward into the interior of the body 1 . A weight 2 is mounted in each recess 16 by a retaining element 4 , allowing adjustment of the center of gravity of the golf club head to a position adjacent to a rear portion of the sole 14 and enhancing the engaging reliability between the weight 2 and the body 1 while improving the adjusting flexibility, assembling reliability, and replacement convenience of the weight 2 .
While the principles of this invention have been disclosed in connection with specific embodiments, it should be understood by those skilled in the art that these descriptions are not intended to limit the scope of the invention, and that any modification and variation without departing the spirit of the invention is intended to be covered by the scope of this invention defined only by the appended claims.
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A golf club head includes a body and a retaining element removably mounted to the body. The retaining element includes a main body and an annular wall extending from a side of the main body of the retaining element. The annular wall defines a compartment for receiving a weight that is retained to the body of the golf club head by the retaining element. A vibration absorbing washer is received in the compartment of the retaining element and mounted to the weight. The vibration absorbing washer absorbs vibration during swing, thereby enhancing assembling reliability of the weight.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to grain dryers and in particular to a novel method and apparatus for cleaning the residue from a grain dryer.
2. Description of the Prior Art
Residue has a tendency to accumulate in the bottom of grain dryers and it has been time consuming to clean such material from the bottom of the dryer.
SUMMARY OF THE INVENTION
The present invention provides a slidable trough at the bottom of a grain dryer which can be inserted or removed from the grain dryer in sections with an external driving handle and wherein the trough is divided into longitudinal sections which can be removed as the trough is removed from the dryer and which can be attached as the trough is inserted into the dryer.
The bottom of the grain dryer beneath the trough is open so that when the trough is removed the residue material in the dryer will fall from the dryer and when the trough is reinserted the dryer is free of such residue.
A feature of the invention is the provision for apparatus and method for rapidly and simply removing residue from a grain dryer.
Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof, taken in conjunction with the accompanying drawings although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cut-away of a grain dryer with the invention installed therein;
FIG. 2 is a sectional view illustrating the invention;
FIG. 3 is a side sectional view illustrating the invention;
FIG. 4 is a bottom view illustrating the invention; and
FIG. 5 is a sectional view through one of the troughs of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a partial cut-away view of a grain dryer 10 with the invention 22 attached thereto. The grain dryer has an end wall 18 and vertical supporting frame members 11, 12 and 13 and cross-frame members 14 and 16. Upwardly and outwardly extending frame members 19 and 21 support the side walls 96 and 97 of the dryer.
FIG. 2 is a sectional view through the grain dryer 10 and illustrates an auger 91 which is mounted on a supporting shaft 92 and has spiral grain moving member 93 which is mounted above the bottom of the dryer and inside thereof between the side walls 96 and 97 as shown. The auguer 91 moves grain longitudinally of the dryer. The invention provides a plurality of troughs which are mounted beneath the auger 91 within the grain dryer 10 and join the side walls 96 and 97 of the dryer so that the grain is supported within the dryer. As shown in sectional view, the side walls 96 and 97 have lower ends which do not meet and a plurality of troughs 24 according to the invention close this area. The trough 24 has a bottom planar portion 69 and upwardly extending lips 53 and 54 at opposite sides thereof which are received in guides attached to the side walls 96 and 97. For this purpose, bolts 98 and 99 extend through the side walls 96 and 97, respectively, near their lower edges and extend through planar top guide members 101 and 102, spacers 106, 107 and bottom slide guides 103 and 104, respectively. Angle iron members 108 and 109 are formed with openings and the bolts 98 and 99 extend therethrough and are secured with nuts 121 and 122 as shown so as to provide the upper and lower slide guides 101, 103, 102, 104 for the lips 54 and 53 of the troughs 24.
As best shown in FIGS. 3, 4 and 5, the housing 22 of the invention is attached to the end wall 18 of the grain dryer and has a top 35 and side walls 25 and an outer end wall 36 in which a slot 61 is formed through which the trough 24 can be inserted and withdrawn from the machine. A crank shaft 41 is supported between side walls 25 and the opposite side wall of the housing 22 and a crank 23 is attached thereto as shown in FIG. 1. A sprocket wheel 42 provided with a plurality of teeth 58 is fixed to the crank shaft 41 and the sprocket teeth 58 are engageable with bicycle links 43 which are attached as by welding to the bottoms of the trough 24. A shaft 38 is mounted above the crank shaft 41 and parallel thereto and carries a roller 39 which engages the upper surface of the trough so as to hold the bicycle or roller chain links 43 in engagement with the sprocket teeth 58 of the sprocket 42.
The trough is made in a plurality of sections and includes a front section 24 and a rear section 74 and one or more intermediate sections 26. As shown in FIGS. 3, 4 and 5, the front section 24 is provided with a stop member 31 which extends downwardly so that it engages the front wall 36 below the horizontal slot 61 so as to limit the inward motion of the front trough 24 into the machine. The stop 31 is provided with horizontal members 51 and 52 as shown in FIG. 4 through which bolts 33 and 32 extend and upon which nuts 56 and 57 are mounted. The bolts and nuts attach the stop member 31 to the trough 24. The front trough 24 can be detachably connected to an intermediate trough 26 by means including a pair of links 44 and 67 which extend beyond the end 23 of the trough 24 and a removable connecting pin 46 can be inserted through openings formed in the links 67 and 44 and through an opening formed in bicycle chain link 68 attached to the bottom of the intermediate trough 26 so as to provide a connection between the end trough 24 and the intermediate trough 26. The pin 46 may be provided with a compressible spring loaded ball 100 such that after it is inserted through the links 67 and 44 as well as the link 68 of the trough 26 the pin 46 will be positively held in the connecting position until spring loaded ball 100 is depreseed by pulling on the handle 47 to disconnect the troughs 24 and 26. Similar connections are made between the bicycle chain links 66 and corresponding chain links of the adjacent intermediate trough as well as between the last intermediate trough and the end trough 74. The end trough 74 is formed with lips 76 and 77 and the bicycle or roller chain 79 does not extend clear to the end 78 of the rear trough 74 as shown in FIG. 4.
As shown in FIG. 3, the end 78 terminates adjacent the end wall 105 of the dryer.
In operation, assuming that none of the trough sections are in place in the dryer, the rear section 74 is inserted with the end 78 passing through the slot 61 until the sprocket teeth 58 engage the chain link 79 and the roller 39 engages the bottom portion of the trough. Then the handle 23 is rotated clockwise relative to FIG. 3 so as to move the rear section 74 through the slot 62 in the end wall 18 of the dryer. Then, externally of the end wall 22, the first intermediate trough 26 is connected to the rear trough 74 by inserting a connecting pin 46 through links such as 67 and 44 to join the two sections longitudinally and then the handle 23 is turned clockwise to move the intermediate trough into the housing 35 and into the dryer. It is to be realized that as the troughs 74 and 26 move into the dryer that the lips of the troughs are guided by the top slide guides 101 and 102 and the bottom slide guides 103 and 104 as shown in FIG. 2. Additional intermediate sections are connected and inserted into the machine until the trough extends substantially the entire length of the dryer and then the front trough section 24 is attached to the intermediate trough 26 with a pin 46 and inserted until the stop 31 engages the wall 36 as shown in FIG. 3. It is to be realized in the position illustrated in FIG. 3 that the end 78 of the rear trough 74 is closely adjacent the end wall 105 of the dryer. For removal of the trough, the handle 23 is rotated counterclockwise relative to FIG. 3 so as to remove the troughs from the dryer thus allowing the residue to fall from the dryer so the machine will be clean before reinserting the troughs.
Although the invention has been described with respect to preferred embodiments, it is not to be so limited, as changes and modifications may be made which are within the full intended scope as defined by the appended claims.
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An end gate cleanout apparatus which includes a plurality of slidable trays that can be connected end to end and moved into the bottom of a grain dryer or other apparatus and including driving means for removing or inserting such removable troughs so as to allow material to fall from the dryer.
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BACKGROUND OF THE INVENTION
This invention relates to altimeters for aircraft, and more particularly to a digital encoding altimeter for measuring changes in altitude of an aircraft and converting such altitude changes to digital signals which are in turn converted to a parallel digital code acceptable for transmission of aeronautical altitude information, such as the ICAO international code.
In the prior art, altitude encoders have been of the absolute or direct reading type. Absolute encoders provide a binary output signal of several bits which is representative of shaft position any time the encoder is turned on. This output is different for different angular positions of the shaft. As an example, an encoding altimeter of the absolute type has eight to 10 code tracks and eight to ten optical sensors to read these tracks. These encoders must be able to resolve 150 - 600 different angular positions in one revolution, and because the code discs are only about 5 centimeters in diameter, it is apparent that errors of greater than a few tenths of a millimeter in either sensor alignment or track registration will cause errors in the output. Moreover, the clearances between the encoder disc and sensors must be on the order of a few tenths of a millimeter, and this close fit makes it possible that shock or vibration, always prevalent in aircraft, will cause some misalignment which will result in erroneous output signals. A much more serious consequence of misalignment occurs if the disc, which is driven by the altimeter mechanism, comes into contact with the nearby sensors. This frictional drag can easily cause greater torque than the mechanism can overcome. The result is a "stuck" altimeter. If, as is usually the case, the pilot is also using this altimeter for an altitude reference, an extremely dangerous situation is created. Such encoding altimeters of the absolute or direct reading type are shown in U.S. Pat. Nos. 3,750,473 and 3,808,431. Other altitude encoding devices are shown in U.S. Pat. Nos. 3,546,470, 3,513,708 and 3,750,474.
Accordingly, one primary feature of the present invention is to provide an incremental altitude encoder which provides the same or repetitive output signal each time the altimeter indicating shaft is moved through a predetermined angle.
Another feature of the present invention is to provide a digital altimeter encoder which includes a counter which is presettable to a predetermined digital count representative of a preselected, altitude function, and to which the incremental signal provided by the rotation of the shaft is added or subtracted to provide an output which is representative of altitude.
Yet another feature of the present invention is to provide a digital altitude encoder which is inherently more accurate, simpler in construction, and less critical in the design of the mechanical parts of the rotating disc and spaced sensors.
Still another feature of the present invention is to provide a digital altitude encoder which utilizes a single track code disc which makes only a predetermined number of transitions per revolution of the shaft, and hence can tolerate errors in alignment of several millimeters, and further provides for clearance between the sensor and disc of several millimeters.
SUMMARY OF THE INVENTION
The present invention remedies the problems of the prior art by providing a digital altitude encoder that utilizes a disc driven by the altitude indicator shaft of the altimeter that makes only ten, or another predetermined number of transitions per revolution, and generates electrical signals that have a relative time of occurrence depending on the direction of rotation of the shaft. These signals are used, in turn, to generate signals representative of an increase in altitude and a decrease in altitude responsive to the relative time of occurrence of the first two signals, and are applied to a counter. The counter is preset to a predetermined digital count representative of a preselected pressure altitude by means of presettable switches. The counter receives the signals representative of an increase or decrease in altitude and increments or decrements the preset count in the counter in response to changes in altitude, the output of the counter comprising a digital signal representative of altitude.
The digital signal from the counter is supplied to a code conversion circuit that converts the digital signals to a parallel digital code acceptable for transmission of aeronautical altitude information (the international ICAO code) and then to a transponder for generating and transmitting a radio frequency signal representative of the altitude. Of course, a read only memory (ROM) may be utilized in place of the hard wired ICAO code converter circuit and programmed to accomplish the ICAO code conversion. In other embodiments, the counter may be replaced with a mini- or microcomputer or -processor which will accomplish the counting and code conversion functions.
The disc is mounted on the indicator shaft of the altimeter and rotatable therewith and has repetitive, alternate, radially disposed opaque and transparent portions (solid protions and radially disposed slots), the disc being disposed between a spaced light source and a pair of light detectors for causing the repetitive opaque portions of the disc to mask one of the detectors before masking the other detector, thereby generating the first and second signals having a relative time of occurrence depending on the direction of rotation of the altimeter indicating shaft.
In another embodiment, the disc mounted on the altimeter indicator shaft and rotatable therewith may have repetitive, alternate, radially disposed light absorbing and reflecting portions, a light source and a pair of light detectors being spaced from the disc and located on the same side of the disc for causing the repetitive reflective portions of the disc to reflect light to one of the detectors before reflecting light to the other detector for generating the first and second signals having a relative time of occurrence dependent on the direction of rotation of the shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the manner in which the above-recited advantages and features of the invention are attained can be understood in detail, a more particular description of the invention may be had by reference to specific embodiments thereof which are illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the appended drawings illustrate only typical embodiments of the invention and therefore are not to be considered limiting of its scope for the invention may admit to further equally effective embodiments.
In the Drawings:
FIG. 1 is a partial perspective view of a conventional altimeter showing the mechanical arrangement of the signal generating means of the present invention.
FIG. 2 is a partial plan view of one embodiment of the signal generating means for generating the first and second signals according to the present invention.
FIG. 3 is a partial vertical cross-sectional view of the signal generating means of FIG. 2 as taken along lines 3--3 of FIG. 2.
FIG. 4 is a partial plan view of a second embodiment of the signal generating means for generating the first and second signals according to the present invention.
FIG. 5 is a partial vertical cross-sectional view of the signal generating means of FIG. 4 as taken along lines 5--5 of FIG. 4.
FIG. 6 is a block diagram showing the functional components of one embodiment of the encoding altimeter according to the present invention.
FIG. 7 is a pictorial view of the first and second signals generated by the signal generating means according to the present invention.
FIG. 8 is a detailed schematic view of the counting and code conversion means of the present invention.
FIG. 9 is a block diagram showing the functional components of a second embodiment of the encoding altimeter according to the present invention.
FIG. 10 is a block diagram showing the functional components of a third embodiment of the encoding altimeter according to the present invention.
FIG. 11 is a block diagram showing the functional components of a fourth embodiment of the encoding altimeter according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a portion of the mechanical apparatus of a conventional pneumatic altimeter is shown, with a portion of the altitude encoding assembly 10 shown in its mechanical relationship to the basic altimeter. The altimeter case 11 houses a frame assembly 12 to which is attached a vertical support plate 13 and a horizontally disposed bracket 14. An aneroid barometer assembly 15 drives a shaft 16 and attached sector gear 17 which in turn drives an indicating shaft 18 by means of a gearing arrangement (not shown). The rotation of the shaft 18 drives attached indicating hands 19 and 20 on the altimeter face 21 for indicating altitude as a function of the atmospheric pressure. Attached to indicator shaft 18 is an interrupting means for disc 22 which rotates with shaft 18 and cooperates with signal generating means 24 for producing a plurality of signals representative of the change in altitude as a function of the rotation of shaft 18, as will be hereinafter more particularly described.
Referring now to FIGS. 1, 2 and 3, one embodiment of the interrupting means cooperating with one embodiment of the signal generating means is shown in greater detail. The disc 22 is mounted on shaft 18 for rotation therewith, and the signal generating means 24 is comprised of a U-shaped frame 25 having extending arms 26 and 28, with space therebetween. The arms 26 and 28 extend over and cover a portion of disc 22 in order that the disc can rotate freely between the spaced arms. Arm 28 carries at least one light source 32 that is connected to a suitable source of electrical power (not shown) by means of conductor 31. Arm 26 carries a pair of light detector elements 34 that are interconnected to the altitude encoder circuitry by means of a plurality of conductors 33.
As shown in FIG. 3, the disc 22 has spaced about its periphery a series of repetitive, alternate, radially disposed opaque portions 30 and slots 29. As the disc 22 rotates in one direction, the opaque portions 30 and slots 29 will alternately pass in front of detectors 34A and 34B for generating first and second signals, by detectors 34A and 34B, respectively, that vary as the opaque or slotted portions, 30 and 29, respectively, pass between the detectors 34A and 34B, and the light source 32. The signal outputs of detectors 34A and 34B are shown pictorially in FIG. 7, as signals 70 and 72. It will be noted that when the disc 22 is turning in a clockwise direction, signal 70, the output of detector 34A, will lead signal 72, the output of detector 34B by approximately 90°. However, if the disc 22 is rotating in a counter-clockwise direction, then the output of detectors 34A and 34B would be reversed, and the signal from detector 34B would lead the signal from detector 34A. The reason for this difference in phase between the detector outputs of detector 34A and 34B, is that with the detectors 34A and 34B spaced in the direction of rotation of the disc, the opaque portion 30 of disc 22 will mask first one and then the other of the two detectors, depending on the direction in which the disc 22 rotates, thereby creating the phase difference between the two signals, as shown in FIG. 7. One cycle of signals 70 or 72 will equal a 100-foot change in altitude as also shown in FIG. 7.
Referring now to FIGS. 1, 4 and 5, a second embodiment of the interrupting means or disc 22 and the signal generating means 35 is shown. The disc 22 is mounted on shaft 18 for rotation therewith, and the signal generating means comprises a frame 36 having extending arm 37 that is spaced from and parallel to the surface of disc 22. Mounted on arm 37 are a pair of spaced light sources 44A and 44B and a pair of spaced detectors 45A and 45B with an extending rib 42 between adjacent light source detector pairs 44A, and 45A and 44B and 45B. Disc 22 has disposed about its periphery repetitive, alternate, radially disposed portions that are light absorbing portions 38, or light reflecting portions 40. As the disc rotates light from the light sources 44A and 44B is alternately absorbed by light absorbent portions 38, or reflected by light reflective portions 40 to the associated detector, 45A or 45B. Rib 42 ensures that the light from source 44A will be reflected only to detector 45A, and that the light from source 44B will be reflected only to the detector 45B. The signals generated by detectors 45A and 45B will be identical to the first and second signals generated by detectors 34A and 34B as hereinbefore described with regard to the first embodiment as shown in FIGS. 2 and 3, and the pictorial view of the signals shown in FIG. 7. The signal output of detectors 45A and 45B will be different in phase, as hereinbefore described, depending on the direction of rotation of disc 22, either clockwise or counter-clockwise, indicating an increase or decrease in altitude.
In practice, it has been found that the disc can be constructed of sheet aluminum that must be flat within 0.25 mm tolerance. A thickness of 0.15 mm has been found acceptable. The outer diameter of the disc may conveniently be approximately 25 mm in diameter and have 10 slots 29 and 10 opaque portions 30. The space between arms 26 and 28 may be approximately 10 mm leaving a clearnace between the arms 26, 28 and disc 22 of some 5 mm, which will avoid the sticking problem associated with absolute encoders.
Referring now to FIGS. 1-3, and 6, the operation of the altitude encoder assembly will be described. As the barometric pressure assembly 15 drives the altimeter indicator shaft 18, as hereinabove described, disc 22 is rotated either in a clockwise or counter-clockwise direction and alternately passes an opaque portion 30, or a slot or transparent portion 29 between light source 32 and detectors 34A and 34B mounted on frame 25. The output of detectors 34A and 34B is applied through conductors 33A and 33B as inputs A and B, respectively, to counting circuit 56. The counter 56 can be preset to a predetermined digital count representative of a preselected function of altitude by means of manual switches 58 and 51. In actual practice, the pilot of the aircraft would set the altitude of the aircraft when on the ground or in the air into the counter 56 by means of manual switches 58 and 51. The manual switches preset counter 56 to a pre-determined digital count representative of the selected altitude function, which in the case of the configuration of FIG. 6, is pressure altitude plus 200 feet. Manual switches 58 are connected to counter 56 by means of conductors 61a-61i. Preset switch 51 applies a PRESET signal to counter 56 via conductor 53 to initially "set" the counter.
As the counter 56 receives the A and B signals from the detectors 34A and 34B, the preset count in the counter is incremented or decremented in response to changes in altitude in accordance with means hereinafter to be described in connection with FIG. 8. The output of the counter 56 is at least a nine bit digital code representative of altitude and applied via conductors 62a-62i to an ICAO code converter 64. The code converter 64 may be a hard wired gate circuit that receives the digital signals from counter 56 via signal paths 62a-62i and converts the digital signals to a parallel digital code (ICAO code) acceptable for transmission of aeronautical altitude information. The ICAO code bits are transmitted via signal paths 65a-65i from code converter 64 to transponder 66. Transponder 66 is a conventional aircraft transponder assembly which will convert code signals 65a-65i into radio frequency signals 68 for transmission.
ICAO code converter circuit 64 could, alternately, be replaced by a read only memory circuit (ROM) 60 (See FIG. 6) which would receive the digital signals representative of altitude from counting circuit 56 via signal paths 62a-62i. The ROM, programmed to effect the code conversion of the digital counter signals to the ICAO code would apply the converted ICAO code to transponder 66 through signal paths 65a-65i.
Referring now to FIG. 8, a more detailed description of the circuitry of counting circuit 56 and the ICAO code converter 64 (See FIG. 6) will be discussed. Altitude switches 58 may comprise at least a pair of selector switches 58A and 58B, for selecting 100's and 1000's of feet respectively, and which when set apply predetermined pressure altitude digital signals to BCD counter 112 and binary counter 114 of counting circuit 56 by means of signal paths 61a-61i. The PRESET switch 51 applies a "preset" signal to counters 112 and 114 by means of signal path 53 to set the counters and enable them to receive the predetermined digital signals from altitude switches 58 which presets the counters to a digital count representative of the predetermined pressure altitude.
The A and B signals from detectors 34A and 34B, respectively, are applied as inputs to a dual Schmitt trigger circuit 102 of the counting circuit 56. The A output of the dual Schmitt trigger 102 is differentiated by the resistor-capacitor network 106 and applied via conductor 102 as one input to gate 108. The A output of the dual Schmitt trigger 102 is differentiated by the resistor-capacitor network 107 and applied via conductor 105 as one input to gate 109. The B output of the dual Schmitt trigger 102 is applied through conductor 104 as second inputs to gates 108 and 109. Gates 108 and 109 detect a change in either signal A or B and generate "up" and "down" signals applied through conductors 110 and 111 as inputs to BCD counter 112 for incrementing or decrementing the counter as the altitude changes.
The outputs of BCD and binary counters 112 and 114 are applied via signal paths 62a-62i to inverters 116, 118 and 120 and to the logic gate array forming the ICAO code converter circuit 64 comprising gates 122, 124, 126, 128, 130, 132, 134 136, 138, 140, 142, 144, 146, 148, 150 and 152 for generating the ICAO code bits C 4 , C 2 , C 1 B 4 B 2 , B 1 , A 4 , A 2 and A 1 on signal paths 65a-65i, respectively.
Referring now to FIG. 9, another embodiment of the altitude encoder is shown. The means of generating signals A and B, preset switch 51, counting circuit 56, ICAO code converter 64 or, alternatively, ROM 60, and transponder 66 are all identical to the circuits identified by the identical reference numbers in the embodiment of FIG. 6, and need not be further described. However, the altitude switches 58 of the configuration of FIG. 6 has been replaced by altitude switches 74, barometric pressure switches 76 and adding circuit 78 which receives indicated altitude from switches 74 by means of signal paths 75a-75i and barometric pressure from switches 76 by means of signal paths 77a-77h. The summing or adding circuit 78 accomplishes the following equation:
PA = IA + (29.92inHg - B) × 1000 feet
Where:
Pa = pressure altitude
Ia = indicated altitude
B = barometric pressure
The pressure altitude information from adding circuit 78 is a digital representation of pressure altitude applied through signal paths 80a-80i as an input to counting means 56 to preset the counter circuits (BCD and binary counters 112 and 114 as shown in FIG. 7) to the predetermined digital count representative of a predetermined pressure altitude.
FIG. 10 illustrates yet another embodiment of the altitude encoder utilizing a microprocessor or computer to accomplish the counting and code conversion processes. Signals A and B are generated by the signal generating means comprising disc 22, light source 32 and detectors 34A and 34B as hereinabove previously described. The signals A and B are applied through signal paths 33A and 33B, respectively, as inputs to microprocessor 82. Signals A and B are also applied to an interrupt circuit 84 through conductors 81A and 81B. The interrupt cirucit detects a change in either signal A or B and causes the microprocesser to examine input signals A and B and increment or decrement the internal counter as appropriate. A PRESET switch 88 is connected through conductor 89 to microprocessor 82 to perform an indentical "preset" function as earlier described with respect to PRESET switch 51. Altitude switches 86 comprise a plurality of switches that are preset in the same manner as pressure switches 58, hereinbefore described, and the output of which are applied to microprocessor 82 through paths 87a-87i. The microprocessor may be any processor or computer means programable to accomplish the counting and code conversion functions. The routines necessarily performed by the processor are:
1. Load counter with pressure altitude information from switches 86 upon receipt of "preset" signal from switch 88. (Routine 94)
2. Convert counter digital information representative of pressure altitude to ICAO code and output information. (Routine 96)
3. Wait for interrupt signal. (Routine 98)
4. Increment of decrement the counter in response to receipt of interrupt signal and condition of A and B. (Routine 100)
The ICAO code digital signals are applied from processor 82 through signal paths 85a-85i to a transponder 90 which converts code signals 85a-85i into radio frequency signals 92 for transmission.
FIG. 11 illustrates another embodiment which is a modification of the embodiment previously described with regard to FIG. 10. The means, circuitry and routines of FIG. 11 having the identical reference numbers as shown in FIG. 10 perform the identical functions as the means, circuitry and routines previously described with respect to the embodiment of FIG. 10 and need not be further discussed. However, altitude switches 86 of the embodiment of FIG. 10 have been replaced with altitude switches 91 and barometric pressure switches 92. Altitude switches 91 are identical to the pressure switches 74 hereinbefore described with respect to the embodiment described in connection with FIG. 9. The indicated altitude is preset on switches 91 and the digital information reflecting the indicated altitude is applied to processor 82 through signal paths 95a-95i. The current barometric pressure is preset on switches 93 and the digital signal levels representative of such barometric pressure is applied to processor 82 by means of signal paths 97a-97h. However, instead of utilizing a separate adding circuit as shown in FIG. 9, the processor of FIG. 11 performs a preliminary routine 99 tht calculates the pressure altitude according to the equation hereinabove explained prior to performing the routine 94 of loading the counter circuit with the pressure altitude. Once the preliminary pressure altitude routine is accomplished, then the embodiment of FIG. 11 performs in an identical manner to that hereinabove described with respect to the embodiment of FIG. 10.
Numerous variations and modifications may obviously be made in the structure herein described without departing from the present invention. Accordingly, it should be clearly understood that the forms of the invention herein described and shown in the figures of the accompanying drawings are illustrative only and are not intended to limit the scope of the invention.
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In one exemplar embodiment, a digital altitude encoder is provided that utilizes a conventional altimeter responsive to atmospheric pressure for rotationally driving an indicator shaft. Attached to the shaft is a disc having repetitive, alternate, regularly disposed solid portions and slots. A light source and a pair of light detectors for receiving light from the source are spaced adjacent the disc to permit one of the detectors to generate a first signal and the other detector to generate a second signal having a relative time of occurrence dependent on the direction of the rotation of the disc. A counting means that is presettable to a predetermined digital count representative of a preselected altitude function receives the first and second signals and increments or decrements the predetermined count in response to changes in altitude. A code conversion circuit receives the digital signal output from the counter and converts the digital signal to a parallel digital code acceptable for transmission of aeronautical altitude information.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119(e)(1) to U.S. Provisional Application No. 60/266,519, filed Feb. 5, 2001, which is incorporated herein in its entirety.
TECHNICAL FIELD
[0002] This invention relates to new and useful improvements in arrow rests for archery bows.
BACKGROUND OF THE INVENTION
[0003] Archers use accessory-type arrow rests attached to archery bows to increase the accuracy of their shots. Arrow rests can provide supports to steady the arrow when the arrow is drawn through the bow. These supports can form a cradle for the arrow to rest upon. It is, however, desirable that the arrow rest not interfere with the flight of the arrow as this interference can affect the accuracy of a shot.
[0004] When an arrow is launched from a bow, large driving forces are placed on the arrow by the bowstring, causing the arrow shaft to deflect. This deflection can be in a lateral direction, a vertical direction, or a combination of both. Supports of an arrow rest that cannot adequately accommodate for these deflections may interfere with the arrow's flight. In other words, the support may not be able to adequately yield to the forces exerted on it by the deflections of the arrow. Instead, by not yielding, the support may exert its own force on the arrow, pushing the arrow off its course. Interference can also result if the arrow rest is not designed to allow the arrow's tail feathers or vanes to freely pass through the arrow rest. Such interference can also throw the arrow off course and/or damage the arrow's feathers or vanes. In addition, care should be taken to ensure that the mechanisms to prevent these interferences do not themselves place undesirable forces upon the arrow.
[0005] The arrow rest may possess other desirable characteristics. For example, the arrow rest should work quietly. Any noise from using the arrow rest, such as when the arrow is being drawn across the supports, might warn the target of the hunter's presence and cause it to flee before the hunter is prepared to shoot. The arrow rest should also create minimal frictional drag on the arrow, as this may slow down the arrow and interfere with shooting accuracy. It is further desirable that the arrow rest be economical to manufacture and durable through the rigors of hunting.
SUMMARY OF THE INVENTION
[0006] With the foregoing in mind, the present invention relates to an arrow rest designed to possess the desirable characteristics of an arrow rest and eliminate, or substantially alleviate, the disadvantages of arrow rests known in the prior art.
[0007] In one general aspect, the invention includes a base and a pair of opposing arrow-supporting arms pivotally coupled to the base. The arms may move independently of each other to yield to forces exerted upon the arms by an arrow in flight. In this manner, the arrow rest would not interfere with the normal flight of the arrow. Additionally or alternatively, the arms may move in a motion wherein the arms move away from and towards the center of the arrow rest. The motion may be in a generally horizontal direction with respect to the base. In other embodiments, the motion may be in a generally vertical direction with respect to the base.
[0008] In some embodiments, the arrow rest may include an elastically compliant, resilient member coupled to the arms for biasing the arms to a home position. The home position may be defined by a stop coupled to, or otherwise integrally formed with, the base.
[0009] In some embodiments, a wheel may be coupled to a distal end of each arm. The wheels may form a cradle upon which one can rest and steady an arrow to be shot from a bow. The wheels may also provide some traction for the arrow, for example by an O-ring placed around the periphery of the wheel. In other embodiments, the arms may terminate in prongs that form a cradle.
[0010] In still other embodiments, the wheels may be coupled to the arms by an adjustment device. The adjustment device can be used to vary the spacing between the arrow rest wheels to accommodate arrow shafts of varying sizes.
[0011] In one aspect of the invention, an arrow rest may include a base; a pair of arrow-supporting arms pivotally coupled to the base; a pair of wheels, each wheel coupled to a distal end of the arms; a stop coupled to the base defining a home position for the arms; and an elastically compliant, resilient member coupled to each arm for biasing the arms to the home position.
[0012] These and other objects, along with advantages and features of the present invention herein disclosed, will become apparent to those skilled in the art through reference to the following description of various embodiments of the invention, the accompanying drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In the drawings, like reference characters refer to the same parts throughout the different views. Also, the drawings are not necessarily drawn to scale, emphasis instead generally being placed upon illustrating the principles of the invention.
[0014] [0014]FIG. 1 is a frontal view of one embodiment of the present invention.
[0015] [0015]FIG. 2 is a rear view of the embodiment shown in FIG. 1.
[0016] [0016]FIG. 3 is a side view of the embodiment shown in FIG. 1.
[0017] [0017]FIG. 4 is a side view of another embodiment of the present invention.
[0018] [0018]FIG. 5 is a perspective view of the embodiment shown in FIG. 1 in one embodiment of a mounting device with an arrow shown in phantom.
[0019] [0019]FIG. 6 is a perspective view of the embodiment shown in FIG. 1 adjusted to another position in the mounting device.
[0020] FIGS. 7 A-D are top, front, and end views, respectively, of the base of one embodiment of the invention.
[0021] [0021]FIGS. 8A and 8B are side and top view, respectively, of the arms of one embodiment of the invention.
[0022] [0022]FIG. 8C is a side view of a stop of one embodiment of the invention.
[0023] [0023]FIG. 8D is a side view of a spring holder of one embodiment of the invention.
[0024] [0024]FIG. 9 is a side view of a spring of one embodiment of the invention.
[0025] [0025]FIGS. 10A and 10B are front and side views, respectively, of one embodiment of the invention.
[0026] [0026]FIGS. 10C and 10D are side and front views, respectively, of one embodiment of the invention.
[0027] [0027]FIGS. 11A and 11B are side and front views, respectively, of one embodiment of the invention.
[0028] [0028]FIGS. 12A and 12B are front and side views, respectively, of one embodiment of the invention.
DETAILED DESCRIPTION
[0029] Embodiments of the present invention are described below. It is, however, expressly noted that the present invention is not limited to these embodiments, but rather the invention is that all equivalents and modifications that are obvious to a person skilled in the art are also included.
[0030] [0030]FIGS. 1,2, and 3 depict front, rear, and side views of one embodiment of the present invention. The arrow rest 2 includes a base 4 and a pair of opposing arrow-supporting arms 6 . The arms 6 can be pivotally coupled to the base 4 . For example, a proximal end of the arm 6 that may be circular in cross-section can be fit into a circular opening in the base 4 such that the arm 6 may pivot freely in the opening. Other means of pivotally coupling the arms 6 to the base 4 will be apparent to those skilled in the art.
[0031] In the present embodiment, the freely pivoting arms 6 can be maintained in a home position by stops 8 disposed on the base 4 to an interior side 10 of the arms 6 . The stops 8 may be of any size and shape which limits the inward pivoting of the arms 6 to define the home position, but does not otherwise affect the workings of the arrow rest 2 . The stops 8 may be attached to the base 4 by any means known in the art, including, but not limited to, friction, solder, screws, and glue.
[0032] An elastically compliant, resilient member, such as a spring 12 , can be coupled to the arms 6 and used to bias the arms 6 toward the home position. The tension of the spring 12 should be such that the arms 6 will not spread apart from the weight of the arrow resting upon the arms 6 , but will move to accommodate for the force applied on the arms 6 from the deflections of the released arrow. In addition, the spring 12 will bring the arms 6 toward the home position when the force is removed. The inward and outward movements of the arms 6 in relation to the center of the arrow rest, in general, are also known as lateral movements.
[0033] The present invention may also include a spring holding or retaining device 14 coupled to a front surface of the base 4 . The spring holding device 14 can be used to secure the spring 12 in position and/or allow for smooth lateral movements. The spring 12 and spring holding device 14 can also be used to secure the arms 6 to the base 4 . The spring 12 , when engaged in the spring holding device 14 , can place a downward force on the arms 6 , preventing the arms 6 from falling out of the base 4 .
[0034] [0034]FIG. 4 depicts another embodiment of an arrow rest 52 . The proximal end of the arms 56 is pivotally coupled to the back portion of the base 54 . The resultant inward and outward movements of the arms 56 (lateral movements) will be in a generally vertical direction.
[0035] The shape of the arms 6 may be of any configuration, limited only in that the proximal end of the arms 6 be pivotally coupled to the base 4 and the distal end of the arms 6 be sufficiently spaced from each other to allow an arrow to rest thereupon and allow a space therebetween to allow for the passage of an arrow's feathers. An example of such a configuration is shown in the embodiment of FIGS. 1, 2, and 3 . The arms 6 are shown as having a non-linear shape. In this embodiment, a first bend 20 in the arm 6 results in an angle α being formed by the arm 6 and an upper surface of the base 4 . The arm 6 can extends from about the first bend 20 in a generally upward and outward direction until the arm 6 forms a second bend 22 . The second bend 22 further extends the arm 6 in a generally upward and inward direction until the opposing arms 6 are sufficiently close to each other to form a cradle for the arrow. As one skilled in the art would appreciate, angle α, arm length, and arm configuration can be manipulated to adjust the size of the cradle, to accommodate arrow shafts of various sizes, and to adjust the distance between the cradle and the base 4 through which an arrow's feathers would pass undamaged.
[0036] The distal end of the arms 6 form a cradle for the arrow. The distal end of the arms 6 may be of any configuration so long as each distal end provides at least one point of contact with the arrow to provide a cradle for the arrow and also creates a space therebetween to allow the arrow's feathers to pass through the arrow rest 2 . The arms 6 , or at least a portion of the arms 6 , may be bare or they may be coated with a low friction material such as TEFLON® (DuPont). The wheels 24 , as shown in the present embodiment, may form the cradle. The wheels 24 are coupled to the distal end of the arms 6 and tilted so that the wheels 24 may make minimal contact with the arrow. The contact should be sufficient to support the arrow, while minimizing the contact between the wheels 24 and the arrow to ensure minimal frictional drag on the arrow. Precision bearings may be used in the wheels 24 to ensure smooth rotation of the wheels 24 . In preferred embodiments, each wheel 24 uses one precision bearing.
[0037] A band 26 of material may encompass the periphery of the wheel 24 . This band 26 can provide traction for the arrow. Traction can aid in preventing the arrow from inadvertently slipping out of the cradle. Contact between the band 26 and the arrow is kept to a minimum to ensure minimal interference during the flight of the arrow. An example of this type of band may be a conventional O-ring. The O-ring may be made of any material such as plastic or rubber that may possess a smooth, substantially friction-free surface and which may provide a slight grip. One type of O-ring is manufactured from elastomeric polymers such as neoprene.
[0038] An adjustment device 28 can be used to couple the wheels 24 to the arms 6 as well as to adjust the size of the cradle formed between the wheels 24 and/or the contact between the wheel 24 and the arrow shaft. The adjustment device 28 may be a hollow, cylindrical-shaped structure disposed along the length of the arm 6 . The wheels 24 may be attached to the adjustment device 28 by a screw, such as an Allen screw, through the precision bearing allowing for free rotation of the wheels 24 . At least one screw 30 , preferable two or more screws, is disposed on the adjustment device 28 . The screw 30 is threaded through the barrel of the adjustment device 28 until it reaches the arm 6 . The screw 30 is loosened to adjust the device 28 along the length of the arm 6 and/or about the circumference of the arm 6 and then re-tightened when the wheels 24 are properly adjusted.
[0039] [0039]FIG. 5 shows a perspective view of the arrow rest 2 shown in FIGS. 1, 2, and 3 with a mounting device 32 for releasably mounting the arrow rest 2 to a bow. The mounting device 32 can be attached to the bow by any means known in the art, such as screws or nuts and bolts. The mounting element 32 includes a series of openings 34 . The mounting device 32 can be attached to the bow at one of these openings 34 . Bows have a {fraction (5/16)}-18 internal thread in the riser (the portion of the bow a user holds on to). A bolt can be put through one of the openings 34 and tightened to the riser. The selection of an opening 34 determines the distance of the arrow rest from the user. For example, attaching the mounting device 32 to the bow at opening 34 a would place the arrow rest 2 the farthest from the user. Attaching the mounting device 32 at opening 34 b places the arrow rest 2 the closest to the user.
[0040] The arrow rest 2 may be integrally formed with the mounting device 32 . Preferably, however, the arrow rest 2 and mounting device 32 are not integrally formed so that they may provide even more flexibility in adjusting the arrow rest 2 to a user's preference. For example, at one end of the mounting device 32 there may be a space 36 running lengthwise from the edge in towards the middle of the mounting device 32 , creating an upper portion 38 a of the mounting device 32 and a lower portion 38 b of the mounting device 32 . The space 36 may terminate in a circular opening to be used as a clamp 40 . In one embodiment, a cylindrical appendage 42 may be attached to, or integrally formed with, one end the arrow rest 2 . The free end of the cylindrical appendage 42 is placed through the clamp 40 . A screw 44 may be used to join the upper portion 38 a and lower portion 38 b of the mounting device 32 . By tightening the screw 44 , the upper and lower portions 38 a , 38 b are pressed closer together, thereby, decreasing the size of the clamp 40 . The mounting device 32 closes around the cylindrical appendage 42 like a vice, holding it in place. The screw 44 can be loosened to increase the size of the clamp 40 to allow for adjustments to the arrow rest 2 in relation to the mounting device 32 and re-tightened when the proper adjustment is made. For example, the arrow rest 2 can be rotated with respect to the mounting device 32 and/or moved closer or further away from the mounting device 32 by sliding the cylindrical appendage 42 through the clamp 40 . FIG. 6 shows the arrow rest 2 and mounting device 32 of FIG. 5 with the arrow rest 2 rotated about 90° in the clamp 40 of the mounting device 32 . The adjustment device 28 can then be used to re-adjust the wheel 24 .
[0041] The arrow rest 2 and mounting device 32 can be used for a right-handed bow or a left-handed bow with some minor adjustments. For right-handed bows, the arrow rest 2 is mounted on the right side of the bow shaft. For a left-handed bow, the arrow rest 2 and mounting device 32 can be swung 180° about the bow shaft so that the arrow rest 2 is on the left side of the bow shaft. In the case of the embodiment shown in FIG. 5, when mounted for a right-handed user, the arrow rest 2 will be the furthest from the user. When mounted for a left-handed user, the arrow rest 2 can be swung about the riser of the bow and the mounting device 32 nearest to the user. In other words, when the arrow rest 2 is used for a right-handed user, the mounting device 32 is to the left of the arrow rest 2 . Conversely, when the arrow rest 2 is used for a left-handed user, the mounting device 32 is to the right of the arrow rest 2 . Another method of converting the arrow rest 2 from a right-handed device to a left-handed device is to loosen the clamp 40 , slip out the arrow rest 2 from its position on the right side of the mounting device 32 , and reattach it in the clamp 40 on the left side of the mounting device 32 . Thus, the back portion of the arrow rest 2 will now be the front portion and the front portion is now the back portion. The arrow rest 2 can now be mounted on the left side of the bow shaft.
[0042] In other embodiments, the arrow rest 2 can be modified for a left-handed user by turning the arrow rest 2 upside down so that the mounting device 32 is to the right of the arrow rest 2 . The openings at the base 4 of the arrow rest 2 , used to accommodate the arms 6 and the stops 8 , may run completely through the base 4 . By disengaging the spring 12 from the spring holding device 14 , the arms 6 can be removed from the base 4 . The stops 8 can be pushed through to protrude out the other side of the base 4 , the “new” top side. The spring holding device can be rotated 180°. The arms 6 can be placed in the openings on the new top side of the base 4 and the spring 12 re-engaged in the spring holding device 14 . The arrow rest 2 can be adjusted in the mounting device as described above and/or the wheels 24 can be adjusted with the adjustment device 28 , as needed.
[0043] The arrow rest 2 , 52 and mounting device 32 may be made of metal, metal alloys, and/or plastic. For example, aluminum may be used for the base 4 as it is strong and lightweight. Spring steel may be used for the arms 6 as it is malleable under sufficient, deliberate pressure, but not under ordinary, casual pressure. With spring steel, slight adjustments can be made to the configuration of the arms 6 . The appropriate material or materials for the arrow rest 2 , 52 and the mounting device 32 will be apparent to those skilled in the art.
[0044] [0044]FIG. 7A is a top view of a base 104 of one embodiment of the invention. FIG. 7B is a front view of the base 104 . FIGS. 7C and 7D are end views of the base 104 . FIG. 7C shows a spring 112 being retained by the spring holder 114 . In this embodiment, the diameter of the cylindrical appendage 142 can be {fraction (3/8)} of an inch. Shown in FIG. 7A are the openings 170 for the stops 108 , openings 172 for the arms 106 , and opening 174 for the spring holding device 114 .
[0045] [0045]FIG. 8A is a side view of an arm 106 of one embodiment of the invention. FIG. 8B is a top view of the arm 106 . FIG. 8C is a side view of a stop 108 of one embodiment of the invention. FIG. 8D is a side view of a spring holder 114 of one embodiment of the invention. In this embodiment, the arms 106 , stops 108 , and spring holder 114 can be made of spring steel and be of 0.091 inches in diameter. Accordingly, the opening 170 for the stops 108 and the opening 174 for the spring holder 114 can be formed by drill #43, creating a 0.089 diameter opening. The opening 172 for the arms 106 can be formed from a drill creating a {fraction (3/32)} of an inch in diameter opening. The opening 172 for the arms 106 are slightly larger to allow the arms 106 to pivot freely in the base 104 . FIGS. 8A and 8B show one possible configuration for the arms 106 . This embodiment shows a first bend 120 and a second bend 122 .
[0046] [0046]FIG. 9 shows one possible elastically compliant, resilient member of the invention. The spring 112 is approximately 1⅜ inches in length, {fraction (3/16)} inch in diameter at the portion to be used to couple the spring 112 to the arms 106 . The diameter is approximately 0.025 inches in diameter. In one aspect, when the arrow rest is fully assembled, the lateral pull at the wheel center can be approximately about 3 to about 5 oz., but this can vary to suit the circumstances when paper tuning. Paper tuning is one process of ensuring that the arrow is flying true.
[0047] [0047]FIGS. 10A and 10B show a top view and a side view, respectively, of a wheel 124 in one embodiment of the invention. The wheel 124 can be made of delron or nylon, although many other materials can be used. FIG. 10B shows a groove 180 where a band of material, such as a tire 126 can be placed. An opening 178 can be to accommodate a wheel bushing 184 . FIGS. 10C and 10D show a side and front view, respectively, of one example of a wheel bushing. In this embodiment, the material can be brass. The outer diameter 186 is about 0.1585 inch. The internal opening 188 is 0.111 inch in diameter to accommodate a 4-40 bolt. The bolt can be {fraction (1/4)} of an inch long and be used with #4 washers. A precision bearing allows movement without excessive space between the bearing surfaces, for example, in this case, the brass bushing 184 would be about 0.002 inches smaller than the wheel 124 with a tolerance of about +/−0.001 inches.
[0048] [0048]FIGS. 11A and 11B show a side and front view of an adjustment device 128 according to one embodiment of the invention. The adjustment device 128 can be a {fraction (1/4)} inch brass round bar. A hole 196 can be created having a {fraction (3/32)} inch diameter, to create a barrel. Two opening 190 are created, drill and tap 4 - 40 to accommodate 4 - 40 Allen set screws of about {fraction (3/16)} of an inch long. Another opening 192 is created, drill and tap 4 - 40 for a wheel bolt. The adjustment device 128 is placed on the arm 106 . To adjust the adjustment device 128 on the arm 106 , loosen the two Allen set screws so as to allow the adjustment device to moved along the arm 106 . The adjustment device 128 can be rotated about the axis of the arm 106 as well as along the length of the arm 106 . Adjusting the adjustment device 128 will also affect the placement of the wheels 124 . Once the wheels 124 are in the desired position, the Allen set screws are tightened to hold the adjustment device 128 in place on the arm 106 .
[0049] [0049]FIGS. 12A and 12B show a front and side view, respectively of the mounting element 132 according to one embodiment of the invention. The opening 134 for attachment to the riser of the bow can be about {fraction (5/16)} th of an inch in diameter. Openings 200 can be drill and taped for 6-32 set screws. The opening 140 to receive the arrow rest can be about ⅜ th of an inch to accommodate a cylindrical appendage. An opening 198 can be created by a {fraction (5/32)} nd of an inch body drill to accommodate a 6-32 Allen bolt 144 .
[0050] According to the present invention, an improved arrow rest is provided that is simple in design and economical to manufacture. The arrow rest includes a base and two arms pivotally coupled to the base. The ability of the arms to move laterally, in a generally horizontal or vertical manner, allows the arrow to yield to the deflections of the arrow from the force of the bowstring upon release. In this manner, the arrow rest provides support and stability without introducing forces of its own to interfere with the flight of an arrow. The arms' ability to yield to forces exerted by the arrow also reduces wear on the wheels. Moreover, the lateral movements of the arms protect the integrity of the arrow rest during use. For example, should the arm accidentally get caught in a branch as one is walking through the woods, the arm will accommodate for this sudden restriction of forward movement by pivoting outward. Should the arms become distorted, however, the user can, by exerting sufficient pressure on the arms, realign them.
[0051] Having described preferred and exemplary embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein can be used without departing from the spirit and scope of the invention. The described embodiments are to be considered in all respects only as illustrative and not restrictive.
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An improved arrow rest including a base and laterally moving arrow-supporting arms is disclosed. The arrow rest provides a support to steady the arrow allowing a user to aim and launch an arrow with accuracy, which also accommodates for the deflections of an arrow during flight, thereby ensuring that no other forces but those of the bow string affect the flight of the arrow. The arrow rest is simple in design, economical to manufacture, adjustable to allow for different arrow shaft and arrow feather sizes, and durable.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to rotary helical screw compressors and more particularly to the use of slide valves for controlling compressor capacity and the discharge pressure of the machine.
2. Description of the Prior Art
Rotary helical screw compressors constitute positive displacement machines, wherein a working fluid is trapped within the closed threads of helical screw rotors whose grooves and lands are intermeshed: the screw rotors being mounted for rotation within intersecting bores with coplanar axes defining the barrel portion of a screw compressor casing. In order to control the capacity of the compressor and to control the pressure ratio or the pressure of the working fluid at compressor discharge, slide valves have been provided to the compressor which are carried within axially extending recesses within the barrel portions of the casing in open communication with the bores and to respective sides of the intermeshed screws. U.S. Pat. No. 3,088,659 to H. R. Nilsson et al and entitled "Means for Regulating Helical Rotary Piston Engine" is exemplary of the employment of such slide valves within rotary helical screw compressors.
In an effort to improve lubrication and cooling of the parts of the helical screw compressor forming the compressor working chamber, attempts have been made to inject liquid refrigerant, water, oil, and relatively low temperature gas into a closed thread of the compressor by means of a port, carried by the slide valve and opening up into the compressor working chamber upstream of the discharge port of the screw compressor and movable with the slide valve to shift the injection port automatically with the shift of the slide valve, which controls the machine capacity by bypassing a portion of the compressed working fluid near the suction side of the machine, back to the suction port. Such liquid refrigerant injection is the subject matter of U.S. Pat. No. 3,795,117 to Moody et al entitled "Injection Cooling of Screw Compressors".
SUMMARY OF THE INVENTION
The present invention is directed to a positive displacement screw compressor of the type wherein a casing is provided with a barrel portion defined by intersecting bores with coplanar axes located between axially spaced end walls and having low pressure and high pressure ports communicating with said bores at opposite ends and helical screw rotors each having grooves and lands mounted for rotation within respective bores with the lands and grooves of respective rotors intermeshed. An axially extending recess is provided within the barrel portion of the casing in open communication with the bores and a slide valve is axially slidable in the recess with the inner face of the slide valve being complementary to the envelope of that portion of the bores of the casing structure confronted by the opening of the recess, communicating with the bore portion of the casing structure with the valve member in sealing relation with confronting rotor structure. Further, the discharge port has at least a portion located in the barrel portion of the casing structure with the valve member being movable between extreme positions, in which, the discharge port is opened and closed. The valve member is of sufficient length to cover the entire remaining length of the confronting portion of the rotor structure throughout the range of movement of the valve member between its extreme positions. The invention resides in means for sensing the pressure of the working fluid within a closed thread closely adjacent to the end of the slide valve closing off the discharge port to the closed thread and means for sensing the pressure of the working fluid at the discharge port and for comparing these pressures. Further, the invention comprises motor means for automatically shifting the slide valve axially to equalize the pressures to prevent undercompression or overcompression of the compressor working fluid within the closed thread by the compressor, prior to discharge.
Preferably, the slide valve carries a sensing port opening up to the closed thread and conduit means within the slide valve communicates the closed thread pressure sensing port to means external of the compressor casing for comparison of the compressor discharge pressure with the gas pressure at the compressor discharge port. The slide valve member is preferably shifted axially by a power piston slidable within a cylinder and connected to the slide valve member by a piston rod. A pilot valve responsive to the pressure differential controls the flow of a motive fluid to and from the respective sides of the power piston to shift the slide valve member to balance the two gas pressures. Preferably, a pilot valve which controls the application of motive fluid to and from the power piston comprises a valve spool having lands at opposite ends subjected directly to the closed thread pressure and the discharge port pressure for controlling the position of the pilot valve spool, and thus the power piston and slide valve member.
In another embodiment of the invention, a pair of slide valves are provided to the screw compressor on opposite sides of the intermeshed screws, the slide valves being identical in this embodiment of the invention. The slide valves are located on opposite sides of the barrel portion of the casing structure and are movable between extreme positions in which a respective port is fully open and the other of which the port is essentially closed with the length of each valve member being sufficient to cover the entire remaining length of the confronting portion of the rotor structure and the slide valves are oriented oppositely. The screw compressor may be driven in either direction, with the ports acting either as suction ports or exhaust ports for the compressor, dependent upon the direction of rotation of the screw compressor. The slide valves in turn, either control compressor capacity or match compressor discharge line pressure with that of the closed thread by shifting of the slide valves. By reversing the direction of rotation of the compressor, the necessity of a reversing valve is eliminated when using the bidirectional compressor in heat pump or refrigeration defrost applications.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a rotary helical screw compressor employing the slide valve member of the present invention to match closed thread pressure at the discharge side of the machine to the discharge line pressure at the discharge port. FIG. 2 is a sectional view of a reversible, rotary helical screw compressor for heat pump use, employing multiple slide valves as a second embodiment of the present invention.
FIG. 3 is a pressure plot of the compression cycle of the rotary helical screw compressor of FIG. 2 for a heat pump system during a cooling cycle in comparison with a screw compressor employing a single, conventional slide valve for capacity control.
FIG. 4 is a pressure plot of the helical screw compressor of FIG. 2 for a heat pump system operating during the heating cycle, in comparison with a similar conventional screw compressor with a single, conventional slide valve for capacity control.
FIG. 5 is an electrical schematic of the motor reversing scheme for an electrical motor employed as the motive power to the compressor of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference to FIG. 1 shows one embodiment of the present invention as applied to a rotary helical screw compressor. The rotary helical screw compressor 10 comprises a casing structure having a central barrel portion 12 located between end wall sections or portions 14 and 16 and providing a working space formed by two intersecting bores (of which bore 18 is illustrated) and which carries a helical screw rotor 20 in mesh with a second helical screw rotor 21 which has an axis coplanar thereto and extending through the barrel portion 12 of the casing structure. The helical screw compressor in this respect is conventional, and both the male and female rotors have helical lands and intervening grooves and are mounted to rotate in the bores by means of bearings. For instance, screw rotor 20 is mounted for rotation on shaft 22 by being supported within bearing .[.20.]. .Iadd.21 .Iaddend.of end wall portion 14, while the shaft 22 is supported by way of anti-friction bearings 26 carried by end wall portion 16 and mounted within an end bell 28 by way of sleeve 30; shaft 22 extending through the end bell 28 and being splined at 32 to permit the screw compressor to be coupled to an electric motor or the like (not shown) as the motive force for driving the screw compressor.
In the embodiment of FIG. 1, the screw compressor is rotated in a single direction only such that gas or other working fluid passes through the suction or intake passage 34 within end wall portion 14 and enters by way of suction or inlet port 36 into the working space formed by the intermeshed helical lands and grooves of respective rotors. There is no capacity control shown in the embodiment of FIG. 1 and the essence of this invention lies in the employment of a slide valve member shown generally at 38 to perform a specific function, that is, to match the closed thread pressure at the discharge side of the machine, that is, adjacent end wall portion 16, with the line pressure of the gas at the high pressure discharge port 40 at the end of slide valve member 38. It is a characteristic of these rotors that the flanks of the lands of the male rotors are convexly curved and with their intervening grooves lying substantially outside the pitch circle of the male rotor while the lands of the female rotor are concavely curved with their intervening grooves lying substantially inside the pitch circle of the female rotor. It is further characteristic of such rotors that the effective wrap angle of the lands is less than 360°. The casing structure, therefore, is provided with the high pressure discharge port 40, the major portion of which lies on one side of a plane passing through the axes of the rotors with the discharge port 40 being located within the high pressure end wall portion 16 of the machine. The discharge port 40 is in fluid communication with discharge passage 42 formed within end bell 28. As mentioned previously, the low pressure end wall portion 14 of the casing structure is provided with an intake or suction passage 34 which communicates by way of suction port 36 with that side of the barrel portion defined by the bores, including bore 18, to the opposite side of the plane passing through the rotor axes relative to high pressure discharge port 40.
The barrel portion 12 of the casing structure is further provided with a centrally located, axially extending, cylindrical recess 44 which is in open communication, at one end, with the high pressure port 40 and at the other end extends axially beyond the low pressure end wall 26. The recess 44 therefore is open to the working space provided by the bores. It is this recess 44 which carries the longitudinally slidable, slide valve member 38. The axial position of slide valve member 38 within the recesses is adjusted by way of piston rod 46 which mechanically couples the slide valve 38 to the power piston 48 of a fluid motor 51 at the opposite end of rod 46. Power piston 48 is sealably and slidably supported within a power piston cylinder 50 which is mechanically coupled to the low pressure end wall portion 14 of the casing structure and is sealed therefrom by way of piston rod 46 which slidably extends through an opening 52 within end wall casing structure portion 14. An end cap .[.52.]. .Iadd.53 .Iaddend.is mechanically coupled to the end of cylinder 50 so as to form a sealed chamber 54 within the cylinder which slidably receives piston 48. The inner surface 56 of valve member 38 confronting the rotors is shaped to provide a replacement for the cut-away portions of the bores. A portion of the slide valve member 38 slidably and sealably engages a recessed portion 60 of end wall portion 14 of the casing such that regardless of the position of the slide valve, the valve member is of a sufficient length to cover the entire remaining length of the confronting portion of the rotor structure throughout its range of movement between the extreme positions as determined by recessed portion 60 and the abutting contact or end face 62 of the slide valve with the high pressure end wall portion 16 of the casing structure.
During compression, an elastic fluid which may be a gaseous refrigerant such as freon, is drawn into and fills the grooves of the rotors through the low pressure port 36. As the rotors revolve, mating pairs of lands of the male and female rotors intermeshed at the bottom or high pressure side of the compressor form chevron shaped working chambers. As the rotors continue to revolve, these working chambers, which constitute compression chambers or closed threads, diminish in volume as the point of intermesh between any two lands determining the apex end of the given compression chamber or thread, moves axially toward the high pressure end wall 64 to diminish the volume of the compression chamber until the chamber runs out to zero bottom as the point of intermesh reaches the plane of the high pressure end wall 64. Closure of the compression chamber is effected by interface 56 of the slide valve 38 which is in confronting and sealing relation with the crests of the lands defining the boundaries of the compression chambers or closed threads. Discharge of compressed fluid is effected when the crests of the rotor lands defining the leading edge of the compression chambers pass the control edge 66 of the slide valve member 38 and which is essentially the right hand edge of valve member 38 to establish communication between the closed thread or chamber and the high pressure discharge port 40. Movement of the slide valve 38 to the left shortens the time of compression while movement to the right increases the time of compression and increases the pressure ratio between suction and discharge of the compressor. Thus, the function, assuming that the initial volume of the closed thread prior to that thread reaching edge 66 of the slide valve constant, permits the slide valve to vary the compression ratio of the compressor. This in effect controls the pressure of the discharge gas from the closed thread to the discharge port 40.
If the pressure within the discharge port 40 is less than that of the closed thread as it reaches edge 66, overcompression occurs, and immediately the pressure of that volume of gas evidenced by the closed thread is decreased to match the pressure in the compressor discharge port or the high side of the machine and thus the overcompression effort is wasted. This can amount to a substantial loss. Likewise, if the pressure of the working fluid as compressed within the closed thread prior to meeting edge 66 of the slide valve member is lower than that of the working fluid within the discharge port 40, this gas will be compressed to a pressure of the port when fluid communication is achieved between the discharge port and the closed thread. Substantial power loss may be experienced as result of either undercompression or overcompression, these losses being visually illustrated in FIGS. 3 and 4.
The present invention is directed to an arrangement for automatically shifting the slide valve member 38 to match the closed thread or working chamber fluid pressure at its point of discharge as determined by edge 66 of the slide valve .[.32.]. .Iadd.38.Iaddend., to the line pressure of the working fluid at the compressor discharge port 40. In this respect, the slide valve is provided with an inclined passage 70 forming at the inner surface 56 of the slide valve, a closed thread sensing port 72 which opens up to the closed thread and permits sampling of the pressure of the compressed working fluid at that point in the compression cycle and just prior to discharge. The slide valve is further bored at 74 and is provided with an annular recess 76 forming aligned openings through which extends a small diameter portion 46a of the piston rod 46. The large diameter portion 46b of this piston rod forms a shoulder 78 which acts in conjunction with the headed end 81 of the shaft to lock the piston rod or shaft 46 to the slide valve 38. The piston rod 46 is centrally bored at 80 extending almost the full length of the rod but being closed off at the enlarged headed end 81. A plurality of radial holes 82 are bored within the piston rod 46 fluid communicating the bore 80 of the piston rod with the cavity within the slide valve 38 defined by the recesses 76 and which opens up to the sensing port 72 via passage 70. Piston rod 46 carries at its opposite end in telescoping fashion a fixed tube 84 which is slidably supported by bore 80 and which is fixed and fluid sealed to end cap 52. A fluid passage 86 within the end cap is fluid coupled by way of line 88 to pilot valve casing 90 of pilot valve 92. The pilot valve 92 carries a longitudinal bore 94 within which slides a pilot valve spool 96 comprising four lands 98, 100, 102, and 104 which are slightly less in diameter than bore 94 within the valve casing. The lands are joined by reduced diameter portions 106. In addition to axial ports 108 and 110, an inlet port 112 fluid connects a line 114 leading from a supply indicated by arrow 116, while ports 118 and 120 are fluid connected to a common discharge line 122 discharging fluid from a pilot valve as indicated at 124. On the opposite side of the valve casing 90, there are provided fluid ports 126 and 128 which lead by way of lines 130 and 132, respectively, to chamber 54 carrying the power piston 48; to respective sides of the power piston 48. The cavity or chamber 54 is fluid sealed from the bore 80 of the piston rod 46. The pilot valve and the power piston comprise a fluid servo circuit of conventional design. A motive fluid as indicated by arrow 116 is selectively applied to either the left or right hand side of power piston 48, while motive fluid on the opposite side is drained by way of the pilot valve 92 to the discharge line 122 and fed back to the sump (not shown) as indicated by arrow 124 from port 118 or port 120, as the case may be.
Of importance to the present invention is the fact that the line 88 fluid couples the closed thread sensing port 72 to the left hand face of land 98 of the valve spool 96 of the pilot valve. The opposite axial port 110 is fluid connected by way of line 136 to the discharge passage 42 of the compressor such that that discharge gas line pressure is applied to the valve spool 96 and in particular to the outboard end face of land 104. The end face surface area of the lands 98 and 104 are identical so that the valve shifts to the right or the left depending upon whether the pressure within the discharge passage 42 of the compressor is higher than the pressure within the closed thread as sensed by port 72 at any instant or vice versa. With the pilot valve spool 96 in the position shown, the working fluid 116 passes to the left hand side of the power piston 48 and tends to move the piston from left to right causing the compressor to discharge gas pressure into the discharge port at a higher pressure level. This, of course, tends to increase the pressure sensed by port 72 which is transmitted by way of passage 70, recess 76, radial passages 82, bore 80 of the piston rod, passage 86 within end cap 52, and passage 88 and port 108 to the left hand end face of land 98 of the pilot valve spool 96. When that pressure exceeds the pressure exerted on the same valve spool on the opposite side thereof through land 104, as defined by the discharge passsage 42, the pilot valve will shift from left to right, thereby causing the application of motive fluid pressure as identified by arrow 116 to the right hand end face of the power piston 48 tending to shift the slide valve member from right to left and causing the pressure of the closed thread at discharge to port 40 to be reduced, by opening that closed thread to the line pressure at port 40 earlier in the compression cycle.
FIG. 2 illustrates a second embodiment of the invention, wherein the rotary helical screw compressor is adapted to operate in either direction, and in which case the suction or low pressure side of the machine becomes the high pressure or discharge side of the machine and vice versa. In respect to this embodiment, and in comparison with the embodiment of FIG. 1, like elements are given like numerical designations. Further, this embodiment is characterized by the employment of a second slide valve member 38' which is slidably carried by the casing structure to the side of the intermeshed screws opposite that of slide valve member 38, and is positively driven between extreme positions by a servo controlled power piston which is essentially the duplicate of the pilot valve and power piston employed in conjunction with slide valve member 38. Slide valve members 38 and 38' are oppositely oriented and are associated respectively with the discharge and suction sides of the machine, however, the order is reversed when compressor rotation is reversed. In this respect, referring to FIG. 2, the rotary helical crew compressor 10' of the second embodiment comprises a casing structure having a central barrel portion 12' located between end wall sections or portions 14' and 16' and providing a working space formed by two intersecting bores in conventional fashion. The bores carry helical screw rotors 20 and 21 having helical lands and intervening grooves in mesh with each other, and having axes coplanar and extending through the barrel portion 12' of the casing structure. Helical screw rotor 20 is mounted on shaft 22 in much the same fashion as the prior embodiment. Many of the details described earlier in conjunction with the embodiment of FIG. 1 are purposely eliminated here to shorten the description, and reference may be had to the description of the embodiment of FIG. 1 if necessary. To illustrate similarity in operation of this embodiment to the prior described embodiment, the working fluid such as a refrigerant gas enters the suction passage 34 and passes by way of suction port 36 to the suction side of the machine, that is, the working chamber as defined by the two intersecting bores housing rotors 20 and 21 and the intermeshed rotors. In this embodiment, however, the control of machine capacity is achieved by way of slide valve member 38' which is located on the opposite side of the plane formed by the axes of the intermeshed screws 20 and 21, from slide valve member 38, both being carried by the central barrel portion 12'. Shaft 22 extends through end bell 28', supported by way of bearings in the manner of the prior embodiment and is provided with a spline 32 which in this case is mechanically connected to a reversible electric drive motor which is schematically illustrated at M in FIG. 5. Contrary to the embodiment of FIG. 1, the screw compressor may be rotated in a reverse direction so as to make the discharge passage 42, the suction passage, and the suction passage 34, the discharge passage. In this arrangement, the casing structure is provided with a port 40 acting in this case as the high pressure discharge port which lies to one side of a plane passing through the axes of the rotor with the port 40 being located adjacent the end wall portion 16 of the machine. Port 40 is in fluid communication with discharge passage 42.
Unlike the prior embodiment, the barrel portion 12' of the casing structure is provided with opposed, centrally located, axially extending cylindrical recesses 44 and 44' which are respectively open to the working space provided by screw rotor bores, the recesses 44 and 44' facing each other. Recess 44 in this case carries the longitudinally slidable slide valve member 38, while recess 44' carries an oppositely oriented, longitudinally slidable slide valve member 38'. In similar fashion to the prior embodiment, the axial position of slide valve member 38 within its recess is adjusted by way of piston rod 46 which mechanically couples slide valve member 38 to the power piston 48 of fluid motor 51 at the opposite end of the rod. Power piston 48 being sealably and slidably carried within power piston cylinder 50, permits the slide valve 38 to shift axially between extreme positions defined by the end wall 64 of casing structure portions 16' and recesses 60 within casing portion 14'. This is accomplished by means of a pilot valve indicated generally at 92 which controls the supply and discharge of pressurized motive fluid emanating from a source indicated by arrow 116 through the pilot valve and to power the cylinder chamber 54 to a given side of the power piston 48 and return therefrom from the opposite side by way of discharge line 124 which leads to the sump as indicated schematically by arrow 122. The pilot valve 92 is communicated to the power cylinder 50 by way of lines 130 and 132. Insofar as the pilot valve 92 is concerned, the valve spool 96 is identical and operates essentially the same as the embodiment of FIG. 1. In similar fashion to the prior embodiment, the inner surface 56 of the slide valve member 38 confronting the rotors is shaped to provide a replacement for the cut-away portions of the casing structure screw rotor bore such that a portion of the slide valve member 38 continuously, slidably and sealably engages a recessed portion of the end wall portion 14' of the casing such that regardless of the position of the slide valve member 38, the valve member is of a sufficient length to cover the entire remaining length of the confronting portion of the rotor structure throughout its range of movement between the extreme positions as determined by a recessed portion 60 and face 64 of the casing structure end wall portion 16'.
In like fashion, with respect to slide valve member 38', its inner surface 56' confronting the rotors is shaped to provide a replacement for the cut-away portion of the bores and a portion of the slide valve member 38' slidably and sealably engages a recessed portion 60' of end wall portion 16' of the casing with the valve member being of sufficient length to cover the remaining length of the confronting portion of the rotor structure throughout its range of movement between extreme positions as determined by recessed portion 60' and the end face 64' of end wall portion 16' of the casing. With the exception that the slide valve member 38' is oriented oppositely to that of slide valve member 38, both slide valve members are similar, and operated similarly except that each performs a different function during machine operation which function changes automatically in response to change in direction of screw compressor rotation. In this respect, the slide valve member 38' is connected by way of piston rod 46' to the power piston 48' of a fluid motor 51 which is slidably carried within cylinder 50'. A fixed tube 84' carried by end cap 52' is telescoped within the rod 46'; rod 46' carrying internally, a passage 80' which by way of the tube 84' fluid connects line 88' to the slide valve member pressure sensing port 72'. This is completed by way of inclined passage 70' and recess 76' within slide valve member 38' and the radial holes 82' within rod 46'. The slide valve member 38' being fixed to the piston rod which in turn fixedly carries the piston 48', causes the slide valve member 38' to move with the piston whose position changes within chamber 54' depending upon which piston side of that chamber receives a motive fluid under pressure through lines 130' and 132' leading from the pilot valve 92'. Pilot valve 92' is essentially the duplicate of valve 92 and the servo system for slide valve member 38' is identical to that for slide valve 38. A motive fluid under pressure enters the pilot valve 92' via line 114' for distribution by way of the valve spool 96' in a selective manner to changer 54' on a given side of piston 48'. Fluid is returned to the sump through line 122' from that side of the piston opposite to that receiving the motive fluid. Line 88' transmits the gas pressure within the closed thread at port 72' of the screw compressor to the pilot valve which acts against the outboard end face of pilot valve land 98'. On the opposite side of the pilot valve, the end face of land 104' is subject to the fluid pressure within line 136' which opens up to the passage 34 within end wall portion 14' of the compressor casing.
Unlike the prior described embodiment, the lines 88 and 136 leading to ports 108 and 110, respectively, of pilot valve 92 and lines 88' and 136' leading to ports 108' and 110' of the pilot valve 92' carry shut-off valves to control slide valve member operation in a selective manner depending upon whether the compressor is being driven in one direction or the other. In this regard, line 88 carries a valve 150, line 136 carries a valve 152, line 136' carries a valve 152' and line 88' carries a valve 150'. These valves may be automatically operated or manually operated and function to close off or open these lines.
Further, within the line 88 and between the cut-off valve 150 and port 108 of the pilot valve, there is a line 54 fluid connected thereto, which line carries a further cut-off valve 158. On the opposite side of the pilot valve, line 156 makes a T connection with line 136 intermediate of the cut-off valve 152 and port 110, this line carrying a cut-off valve 160. In identical fashion line 88' is provided intermediate of cut-off valve 150' and port 108', with a T connection line 154' which carries a cut-off valve 158', and line 136' between port 110' and a cut-off valve 152' is fluid connected to line 156', which line 156' carries a cut-off valve 160'.
Lines 154, 154', 156 and 156' may have selectively applied thereto fluid pressure signals permitting the pilot valve spools, for respective pilot valves to be shifted either to the left or right to positively drive the slide valve members in a manner determined by desired system operation. This permits one of the two slide valve members 38 or 38' to perform the function of capacity control, while the other seeks to balance automatically the closed thread pressure within the compressor working chamber to the compressor discharge line pressure at the discharge port.
For instance, in the illustrated embodiment of FIG. 2, assuming that passage 34 is the suction passage and passage 42 is the discharge passage of the compressor, as indicated by the arrows therein, slide valve member 38 functions to balance the closed thread pressure to the discharge line at the discharge port 40, while slide valve member 38' provides capacity control. In this case, for the servo system controlling slide valve member 38, cut-off valves 158 and 160 within lines 154 and 156 are closed and valves 150 and 152 within lines 88 and 136 are open. Within the servo system for slide valve member 38', the cut-off valve 152' within line 136' is closed as is the shut-off valve 150' in line 88. Further, valve 160' within line 156' and valve 158' within line 154' are open. The effect of this is to permit the pilot valve spool 96 to compare in terms of lands 98 and 104, the pressure within the closed throat at port 72 with the line pressure at the discharge side of the machine, that is, the pressure within discharge passage 42. The slide valve member 38 therefore shifts automatically to the right or left to balance these two pressures. Under this set-up, valve member 38 performs the identical function in this embodiment in this case as it does in the embodiment of FIG. 1.
With valves 152' and 150' closed insofar as the pilot valve 92' is concerned, the slide valve member 38' is shifted to the left or right to perform the function of capacity control. As indicated by the arrow CP upstream of valve 160' within line 156', the application of a controlled pressure signal which the arrow schematically identifies, when applied to the end face of land 104' of the valve spool 96', causes the pilot valve spool 96' to shift from left to right as shown and permitting the application of motive fluid through line 130' to the chamber 54' and which operates against the right hand end face of the power piston 48'. This would tend to shift the slide valve member 38' from right to left and in this case would decrease the area of port 36 to the intermeshed screws by shifting edge 66' of the slide valve member 38' to the left. The screw compressor design is such that the machine has minimum capacity when the slide valve 38' is positioned where its end face 62' abuts the end face 64' of casing end wall portion 14'. As the slide valve member 38 shifts therefore from left to right, the capacity of the machine increases, since more and more of the working space defined by the intermeshed screws and the bores carrying the same is exposed to the suction part. The incoming gas from suction passage 34 is subjected to isentropic expansion and recompression without any work being expended by the machine, until the pressure of the trapped volume within the closed thread reaches inlet pressure during reduction of that trapped volume. Since the intermeshed screws are open to the suction side of the machine by way of edge 65' of the slide valve member 38', a given volume of suction gas becomes sealed within a closed thread and that volume expands as the closed thread volume momentarily increases prior to recompression and it is during this time of the cycle that isentropic expansion and recompression occurs. However, this is achieved without absorbing any power from the compressor until inlet pressure is reached during subsequent reduction of the trapped volume.
Reference to FIG. 3 shows a pressure, volume plot during a typical cooling cycle of the compressor of FIG. 2, wherein the isentropic expansion and recompression of ideal unloading is provided by the slide valve member 38' of the present invention. Expansion may occur from A to B and recompression from B to C without work in the machine supplied with the dual slide valve 38' of the present invention in comparison with a conventional slide valve indicated by that portion of the curve from points A to B' and thence to C'. The prior art case involves the slide valve member permitting initial compression of the trapped volume of which a portion is then returned back to the suction side of the machine and in which the partial compression of the trapped volume is lost effort.
Should it be necessary to decrease the capacity of the machine, a control signal is applied to line 154' with cut-off valves 160', 152', 150' closed. Valve 158' is open to permit a control signal to be applied to the end face of land 98', shifting the spool valve 96' to the left and permitting high pressure fluid to be applied to the left hand side of the power piston 48', shifting the unload slide valve member 38' which is acting as a capacity control or unload mechanism from left to right to load the machine.
While slide valve member 38' is acting to control the capacity of the machine, depending upon demand, the slide valve member 38 is shifting to automatically match the close thread pressure as sensed but port 72 with the compressor discharge line passage 42 and just downstream of discharge port 40. In this case, valves 150 and 152 are open and valves 158 and 160 are closed. The effect of this operation may be further seen by reference to FIG. 3, wherein assuming that the gas within the closed thread is compressed to a degree greater than that of the gas pressure within the discharge line 42, upon that closed thread reaching the point where it is exposed by way of edge 66' of the slide valve member 38 to the discharge port 40, immediately thereof gas pressure is equalized with that of discharge passage. The overcompression loss or drop in pressure and thus the wasted energy may be seen by comparing that portion of the curve from B to E and the work involved, with the area encompassing points D, E and F. Thus, the variable discharge cut-off allows ideal compression process to be achieved, and the ideal discharge point is always maintained regardless of the change in the system conditions to which the compressor is subject.
By referring to FIG. 5, it may be seen that the motor M is provided with three windings, A, B and C, corresponding to a three phase source 1, 2, 3. Circuit breakers 170 permit the motor leads 172, 174, 176 to be cut off from the line. Any two of the leads may be reversed, and a solenoid operated switch 178 includes a coil 180, which when energized switches lines 174 and 176 relative to the phases 2 and 3 of the source such that winding A is connected to phase 3 and winding C is connected by way of line 176 to phase 2 through movable contacts 180. The motor should be disconnected from the three phase source prior to energization of solenoid 178 and switching of the contacts 180.
This permits the compressor 10' to be driven in either of two directions which makes the compressor particularly applicable to heat pump operation or permits the compressor to be driven in a reverse manner to supply hot refrigerant to the condenser coil for cyclic defrosting without the necessity of employing reversing valves or the like which are conventional to such systems. Further, with reference to the compressor 10' being employed in a heat pump application, during the heating cycle, the pressure curve illustrated in FIG. 4 shows by way of a pressure volume plot, the manner in which the compressor 10' employing the multiple slide valve members of the present invention eliminates the loss due to conventional slide valve unload through the isentropic expansion and recompression. In this case passage 34 acts as the discharge passage and passage 42 acts as the suction passage. In addition to the conventional side unloading loss which is eliminated by the arrangement of the present invention and which is graphically illustrated by the area as defined by points A, B', C', the energy loss due to undercompresson with the conventional machine comprises the area defined by points E, D, D'. Thus, without being able to sense the pressure within the closed thread, undercompression occurs, and when that closed thread opens up to the discharge side of the machine, the closed thread pressure is immediately raised to discharge port pressure thus absorbing excess energy to discharge the compressed gas and the gas which backflowed into the closed thread volume.
While not shown, particularly where the compressor is employed in a heat pump system, the compressor and drive motor may be hermetic with the gas passing directly over the motor windings. In this case, the motor is directly cooled by either the suction or discharge, the motor being cooled by the compressor discharge on one cycle such as the cooling cycle, and being cooled by means of the suction gas on the other cycle.
It may be seen from the description of the above that absolute minimum power consumption results regardless of operation cycle, condensing temperature, percentage of load on the compressor, etc. The compressor seeks by sensing parameters associated with the compressor itself to balance the closed thread pressure to the discharge line, in an automatic manner without the necessity of complex, external control means.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.
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An axially shiftable slide valve member in a rotary, helical screw compressor carries a port which senses the pressure of the working fluid in the trapped volume just before uncovering of the closed thread to the discharge port and compares that pressure with the line pressure at the discharge port and shifts the slide valve member to balance the pressures and prevent overcompression or undercompression of the compressor. The screw compressor may be provided with two identical but oppositely oriented slide valve members on opposite sides of the intermeshed helical screws with one slide valve member controlling the capacity of the compressor and the other balancing the closed thread pressure at discharge with discharge line pressure. Compressor rotation may be reversed to eliminate the need for a reversing valve where the compressor operates in heat pump or reverse flow defrost refrigeration applications, with the two slide valves trading functions.
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TECHNICAL FIELD
[0001] This invention pertains to methods of making sintered articles comprising the intermetallic compound, gamma titanium aluminide (γ-TiAl), as the major metallurgical phase with other minor phases and also containing other alloying elements. More specifically, this invention pertains to methods of sintering compacted preform mixtures of substantially pure titanium particles with particles of rapidly solidified mixtures of aluminum and the other alloying element(s) to form such articles with low porosity and desired microstructures.
BACKGROUND OF THE INVENTION
[0002] Increasingly, the material mix used in trucks and automobiles is changing from low strength, low carbon steel to materials which can, cost-effectively, offer higher specific strength (strength/density). Titanium alloys offer some of the highest specific strengths (strength/density) of all structural alloys, good corrosion and oxidation resistance and good fatigue properties and so should be appealing for automotive applications. But because material and processing costs for titanium-based alloys have not been attractive, titanium and titanium-based alloys and compounds have found only limited application.
[0003] Thus, there remains a general need for new practices for manufacturing titanium alloys because they can find applications in automotive vehicles such as, for example, in valves, connecting rods, and springs, and other engine components. The substitution of lower density titanium alloys for ferrous alloys may enable higher maximum engine operating speeds and up to an 8% increase in engine power. Since new electrolytic processes are now becoming available that can offer pure Ti powder at very low cost, there is increasing interest in developing new methods for manufacturing sintered Ti-alloys using these low cost Ti-powders.
[0004] Gamma titanium aluminide, γ-TiAl, (as indicated with equal atomic proportions of titanium and aluminum) is a material considered for use in aeronautical applications. It could find automotive applications if it could be processed at acceptable cost levels. It is often prepared in combination with minor proportions of one or more of Nb, Cr, Mn, Mo, Si, Cu, Fe, Sn and V, generally indicated as X, and added for selective enhancement of ductility, corrosion or oxidation resistance or other engineering attributes. But there is a nearly one thousand degree Celsius difference in the melting points of titanium and aluminum. This fact and other processing issues have complicated the preparation of useful article shapes of γ-TiAl—X compositions for automotive applications when using blended elemental powder mixtures of the desired composition.
[0005] There is, therefore, a need for an improved method of making titanium alloy articles in general, and there is a particular need for making articles comprising γ-TiAl with relatively minor alloying additions where the individual elemental additions have widely-varying melting points.
SUMMARY OF THE INVENTION
[0006] This invention provides general practices for making sintered articles of titanium-based alloys and, more specifically and preferably, for making sintered articles comprising gamma titanium aluminide as the major metallurgical phase. A candidate sintered titanium alloy for automobile engine components such as valves and connecting rods is γ-TiAl—X, where X represents one or more minor additions of Nb, Cr, Mn, Mo, Si, Cu, Fe, Sn and V, among others.
[0007] In accordance with practices of this invention, substantially pure particles of titanium are used in a sintering process. The titanium particles are prepared to have suitable size(s) for sintering in a mixture with particles containing aluminum and X in combination. A generally homogeneous melt of aluminum with the one or more elemental alloying constituents (X) is prepared with the X constituent(s) dissolved in the liquid aluminum. The liquid is then rapidly solidified by a suitable practice to obtain flakes or other particle shapes. Preferably the particles are a generally homogenous mixture of aluminum and the X element(s), but some small, finely-dispersed precipitates of an X-containing phase may be present. If necessary the solidified particles of aluminum and X may be reduced to a particle size (or size range) for mixing and sintering with the titanium particles. But an important aspect of this invention is the preparation of rapidly solidified (or otherwise homogenized) particles of Al—X prior to sintering, so that the X elements are initially carried or transported in aluminum, preferably liquid aluminum, for inter-diffusion with titanium particles during the sintering process. This practice is found to hasten the sintering process, to more reliably produce desired microstructures, and to produce less porous sintered products.
[0008] In the practices of this invention, directed to shaped, sintered articles of γ-TiAl—X composition, the elemental proportions of titanium and aluminum will be appropriately close to equal atomic proportions. The respective values of atomic weights and densities for titanium and aluminum are such that the sintering mixture may contain a few more Al—X particles than titanium particles (depending on initial particles sizes). In many embodiments, an initial excess of relatively small aluminum particles around larger titanium particles may be advantageous in achieving more rapid and effective inter-diffusion between the mixed particles in a compressed particle body because of the large difference in the melting points of titanium and aluminum. But, in each practice of the invention, the respective sizes of the Ti particles and Al—X particles are determined and specified to achieve effective sintering rates and full consolidation of the mixed particles to achieve the desired microstructure in the sintered product.
[0009] As described in detail in this specification, a suitable mixture of Ti particles and Al—X particles is prepared and the mixture shaped and compacted in a suitable mold or die to obtain a self-sustaining green-body for sintering that is of a predetermined precursor shape. And the compacted body is sintered. The time-temperature-pressure program for sintering is determined by trial, experience, computer modeling, or the like to obtain a sintered microstructure of a gamma titanium aluminide phase with X in solution in the γ-TiAl phase, or with one or more secondary phases of predominately X, a mixture of aluminum (or Al 3 Ti) and X, or the like. In most embodiments, the time-temperature-pressure processing program will be conducted to maintain a liquid aluminum-rich phase to promote rapid diffusion of aluminum and the X constituents into the solid, growing titanium particles and diffusion of titanium into the liquid aluminum phase. Initial diffusion of aluminum into the titanium particles may initially produce some unwanted metallurgical structures (e.g., Al 3 Ti) that will be reduced or replaced by further inter-diffusion between the particles in the precursor compact.
[0010] This invention seeks to promote more rapid sintering of alloys and compounds of titanium and aluminum with minor additions of one or more other constituents such as Nb, Cr, Si and others which may be present, collectively, in an amount from 0.1 to 10 atomic %. It is preferred that substantially equal atomic proportions of Al and Ti are employed so that the sintered compact will comprise substantially γ-TiAl. The minor constituents, collectively and individually, will be generally referred to as X so that, unless otherwise indicated, X may be used to refer to a single additive constituent or to multiple additive constituents. For convenience, the resulting aluminide will be referred to as TiAl—X where it may be understood that, at the conclusion of the sintering process, the structure will comprise γ-TiAl as a major phase with X in solid solution or as a constituent of another phase. The final microstructure desired depends on the properties required.
[0011] Rapid sintering to form the desired γ-TiAl composition may be achieved by first melting aluminum at a suitable temperature in the presence of X to form a homogeneous liquid alloy of aluminum and X. This liquid Al—X alloy may then be rapidly cooled to suppress any phase transformation on cooling. Many X do not form extensive solid solutions with aluminum and so would, if the alloy were cooled slowly, precipitate particles of a different composition than the melt composition. Rapid cooling, for example splat cooling or gas atomization using water as the atomizing agent may result in higher cooling rates and, at least substantially suppress such segregation. Even if segregation is not completely suppressed the scale of the segregation will be markedly reduced with any precipitates finely-dispersed within the small individual particles. This will facilitate rapid re-homogenization of the molten alloy during sintering if the selected sintering temperature equals or exceeds the initial melting temperature of the Al—X composition.
[0012] Sintering may be conducted at a temperature greater than the liquidus temperature of the rapidly cooled aluminum particles but lower than the melting point of the substantially pure titanium particles. On melting, the aluminum may be wicked into the pores between the titanium particles by capillary action and wet the particles so that the entire surface area of the particles may participate in the diffusion process. Solid state diffusion of titanium will occur, and so, to limit the diffusion distance, the particle size may be small, ranging from between 1 and 10 micrometers and preferably less than 3 micrometers. Since the particles of aluminum alloyed with X will melt, the size of the aluminum-containing particles is not critical to diffusion. Preferably however, since the volume ratio of titanium to aluminum will be about 1.07 to 1.0 or so, the aluminum particles may be of comparable or lesser size than the titanium particles, for efficient particle packing.
[0013] The presence of liquid generally increases the rate at which a powder compact will consolidate. First, as noted, because the liquid effectively wets the remaining solid particle and increases the active area of the particles participating in the diffusion, particularly during the early stages of the process. Second, diffusion will occur more rapidly in, or through, a liquid than a solid.
[0014] If however the liquid forms a higher melting point compound with the remaining powder, as is observed in existing practices, these advantages may be lost if the shell of higher melting point compound such as Al 3 Ti, formed on the particle, slows and impedes further diffusion.
[0015] But pre-alloying the aluminum with X enables the aluminum-rich liquid to co-exist with Ti as well as any high melting point compound, such as Al 3 Ti, which may form, so that rapid interdiffusion of Ti and Al may be obtained largely throughout the liquid-diffusion process. In some cases it may be necessary to gradually increase the temperature as the reaction proceeds to maintain the liquid present.
[0016] Also, such Al—X liquid alloy reaction with titanium results in less porosity than obtained in solid-solid diffusion processes.
[0017] Other objects and advantages of the invention will be further apparent from a detailed description of illustrative embodiments of the invention will follow in this specification. Reference is made to drawing figures which are described in the following section of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 illustrates the progress of sintering to form titanium aluminides with minor alloying additions from blended elemental powders according to the prior art.
[0019] FIG. 2 illustrates the progress of sintering to form titanium aluminides with minor alloying additions from titanium powder and aluminum pre-alloyed with the minor alloying addition according to the practices of the invention.
[0020] FIG. 3 shows a gas atomizer for production of metal powder.
[0021] FIG. 4 schematically illustrates a splat cooling apparatus.
[0022] FIG. 5 shows the Aluminum-Niobium binary phase diagram and identifies the liquidus temperatures for Al—Nb alloys containing 1 wt %, 3 wt. % and 5 wt. % Nb.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] Titanium-based alloys in general and titanium aluminides, especially γ-TiAl, have long been recognized as offering potential benefits in reducing vehicle mass, particularly the mass of vehicle engines. But raw material and fabrication costs have limited enthusiasm for titanium alloy components and they have found only limited application.
[0024] Electrochemical processes for preparing titanium powder at low temperature have lowered its cost relative to powder prepared by melting and gas atomization so that interest has revived in titanium alloys prepared by powder metallurgy techniques.
[0025] γ-TiAl commonly contains minor proportions of one or more of Nb, Cr, Mn, Mo, Si, Cu, Fe, Sn and V, collectively and individually referred to as X in this specification. X, in total ranging from 0.1 to 10 atomic %, is added to enhance particular engineering characteristics, most commonly high temperature oxidation resistance but Nb additions, in particular, are also effective in improving high temperature strength.
[0026] Such γ-TiAl—X compounds may be prepared by sintering commingled finely divided generally pure powder mixtures of Ti, Al and X. But the process proceeds slowly, requiring extended sintering times. Also, because solid-solid interdiffusion occurs the resulting sintered compound frequently contains high levels of porosity from the large differences in the diffusivities, of the diffusing species.
[0027] The origin of this behavior may be seen by consideration of FIGS. 1A-E which is illustrative of the prior art. An initial compact 10 of aluminum 12 , titanium 14 , and X particles 16 is prepared ( FIG. 1A ) with near equal atomic proportions of titanium and aluminum. The compact 10 is then heated under pressure, generally in the presence of a reducing or inert atmosphere, such as hydrogen, argon, or under vacuum, to a suitable sintering temperature. The sintering temperature is commonly greater than the melting point of aluminum but less than the melting point of either titanium or X rendering the aluminum molten so that it forms a liquid film 12 ′ ( FIG. 1B ) which wets and coats titanium particles 14 and X particles 16 . At some later time, as seen in the expanded representation of a single particle and aluminum film shown in FIG. 1C , interdiffusion of aluminum and titanium occurs across titanium particle surface 15 ( FIG. 1B ) forming a layer of Al 3 Ti intermetallic compound 18 around the core of partially consumed titanium particle 14 ′. Particle 16 ( FIG. 1B ), may be incorporated into the growing shell of Al 3 Ti or, as shown, remain immersed in the molten aluminum-rich film 12 ′ while undergoing minimal dissolution to form particle 16 ′. At a still later time, all of the molten elemental Al has been consumed to form an expanded shell 18 of Al 3 Ti ( FIG. 1D ) surrounding an inner core 20 of a mixture of TiAl and Ti 3 Al incorporating X particle 16 ′. As a result of the differing diffusivities of aluminum and titanium pores or voids 22 have formed in core 20 . At the conclusion of the sintering process ( FIG. 1E ) the entire volume 24 has been transformed to its final composition and comprises a mixture of TiAl and Ti 3 Al with some dissolved X. The remainder of the X is embedded in the microstructure as particle 16 ′ and voids 22 persist, now, like remnant X particle 16 ′, embedded in volume 24 .
[0028] FIGS. 2A-E illustrate the practice of the invention. FIG. 2A shows a powder compact 110 of titanium particles 114 and of Al—X aluminum particles 126 . As will be described below the Al—X particles may be a supersaturated solution of X in Al, or a fine dispersion of X or a stable or metastable compound of aluminum and X. Again it is preferred to conduct sintering under a reducing atmosphere, an inert atmosphere, or vacuum. Maintaining an applied pressure on compact 110 while raising the temperature to a sintering temperature which is less than the melting temperature of titanium but greater than the liquidus temperature of the Al—X particles will result in the structure illustrated in FIG. 2B in which titanium particle 114 is surrounded by liquid Al—X, 126 ′. At some later time ( FIG. 2C ), partial dissolution of titanium has occurred but that titanium particle 114 ′ is surrounded by Ti-enriched Al—X liquid 126 ″, now containing some Al 3 Ti particles 118 . At a still later time ( FIG. 2D ), after yet further diffusion, the structure consists of a center core of a TiAl+Ti 3 Al mixture 120 , still surrounded by Ti-enriched Al—X liquid 126 ″ containing Al 3 Ti particles 118 . At the conclusion of the process, illustrated in FIG. 2E , a generally uniform, pore-free microstructure of TiAl and Ti 3 Al containing dissolved X (stage 120 ) results.
[0029] Beneficially, the revised process maintains a liquid phase throughout the sintering process so that no solid-solid diffusion and resulting porosity results from the dissimilar diffusion coefficients of aluminum and titanium. The liquid phase is retained at the Ti particle surface because although the components are the same as in the prior art, two of the components, aluminum and X, are present as a single liquid phase rather than as two distinct and separate phases. The resulting ternary interdiffusion, in accord with the phase rule, makes it thermodynamically possible for the liquid phase to co-exist with the Ti—Al intermetallic compound Al 3 Ti as sintering proceeds. If required, the sintering temperature and/or pressure may be systematically varied during sintering to maintain a liquid phase in contact with Ti.
[0030] The benefits of the invention may only be realized provided the aluminum and X are present as a single phase before appreciable inter-diffusion of Al and Ti occurs. To achieve this, suitable powder or flake-like particles of Al—X may be prepared by the methods illustrated in FIGS. 3 and 4 . In FIG. 3 , Aluminum and X in appropriate proportions are melted together, generally under inert atmosphere to produce an Al—X liquid 30 of homogeneous composition in furnace 37 comprising heating elements 32 and furnace wall 34 . Homogeneous liquid 30 is then expelled, through nozzle 36 as molten metal stream 38 . Water or gas jets 40 , originating from nozzles 42 are mounted on circular manifold 44 which surrounds molten metal stream 38 . Each of jets 40 is oriented and positioned to direct a jet of water or gas at common location 41 of molten metal stream 38 . When manifold 44 is fed by pressurized water or gas from pressure source 46 the water or gas is directed toward location 41 on the molten metal stream. The cooperative effect of all of the impinging fluid flow on molten metal stream being to disperse and break up the metal stream to form molten metal particles 50 ′, which, on solidifying are collected as metal powder particles 50 . Even with gas cooling, cooling rates of up to about 100 K/second may be achieved.
[0031] A method for producing metal powder or metal flakes under even more aggressive cooling is illustrated in FIG. 4 . Again a homogeneous molten alloy of Aluminum and X is prepared. In this case the flow of molten metal emerging from a nozzle (not shown) breaks up to form a stream of molten metal droplets 56 . The molten metal droplets 56 are directed against surface 62 of disc 58 spinning about its axis 64 in a direction indicated by arrow 66 . Disc 58 is fabricated of a high conductivity material like substantially pure copper. When contacted by droplet 56 the droplet will at least flatten as shown at 156 or may splat and spread into an irregular generally planar shape depending on the impact velocity v. The spread droplet 156 , by virtue of its large surface area in contact with heat extracting disc 58 , will cool rapidly and at least begin to solidify before being thrown off the surface 62 of spinning disc 58 by centrifugal force as solid or near-solid particles 156 ′. Cooling rates achievable with splat cooling generally range from about 10 4 K/second for the configuration shown and may be even greater in devices which trap the droplets between opposing heat extracting surfaces and expel them as flakes.
[0032] In an alternative embodiment the alloy may be melt spun, a process in which a thin stream of liquid is brought into contact with the rim of a cooling wheel, normally fabricated of copper. By appropriate adjustment of the flow rate of the liquid stream, a thin ribbon of rapidly-cooled alloy may be formed. In this embodiment at least a second step to reduce the ribbon to a plurality of appropriately-sized particles or flakes suitable for sintering will be required.
[0033] The rapid cooling obtained with any of these cooling practices will limit the extent to which the molten aluminum may segregate on cooling. Consider FIG. 5 , which shows the Aluminum-Niobium phase diagram and is representative of the phase behavior of Al—X alloys generally. Nb is substantially insoluble in solid aluminum and dissolves to an appreciable extent in liquid aluminum only at temperatures significantly elevated above the melting point of aluminum (around 660° C.). For example 1 wt. % Nb Al—Nb alloy 76 will be fully molten at about 1100° C.; 3 wt % NbAl—Nb alloy 74 at about 1250° C. or so; and alloy 72 , comprising 5 wt. % Nb at about 1350° C.
[0034] Cooling a homogeneous solution of Al—X containing 1-5% by weight of Nb, at conventional cooling rates encountered in castings, will precipitate NbAl 3 which will grow and coarsen as the melt cools to about room temperature of 25° C. or so to form a microstructure of coarse NbAl 3 particles in a substantially pure Al matrix. This coarse dispersion of NbAl 3 , will resist re-dissolution in the aluminum so that the benefits of a single homogeneous liquid Al—X composition illustrated in FIG. 2 may not be obtained. This problem may be resolved by rapidly cooling the Al—X melt as described to both inhibit precipitation of NbAl 3 and to ensure that any NbAl 3 which does form will be in the form of small dispersed particles. Rapid cooling will therefore result in a less-than-equilibrium concentration of NbAl 3 particles in a Nb-supersaturated Al matrix, a structure which may be readily reconstituted into a homogeneous liquid very early in a sintering process.
[0035] For ease of handling and compacting into a powder compact more regularly-shaped particles such as those prepared by gas atomization are preferred. But irregular particles, even very irregular splat-cooled particles, are functionally acceptable since on melting during sintering, capillary action will convey the liquid throughout the compact and ensure that all Ti particles are wetted.
[0036] It will be appreciated that the re-formation of a homogenous liquid of Al and Nb on remelting the rapidly-cooled Al—Nb particles requires that the temperature be sufficient to decompose all of the NbAl 3 particles. But, on heating, the substantially pure aluminum matrix will melt first. At a slow heating rate, the supersaturated aluminum may spend appreciable time at a temperature suitable for precipitating excess Nb, forming yet additional NbAl 3 and molten aluminum. If significant reaction occurs between the molten aluminum and titanium particles before a temperature suitable for dissolution of NbAl 3 is attained, not all of the benefits of the invention may be realized. It is therefore preferred that the powder compact be rapidly heated, preferably at a rate comparable to the rate at which it was cooled, so that rapid dissolution of NbAl 3 results to render a homogeneous Al—Nb liquid early in the sintering process. Spark plasma sintering or SPS (also known as field assisted sintering technique or pulsed electric current sintering) is a suitable sintering process. The main characteristic of SPS is that the pulsed DC current is passed through the powder compact so that heat is generated internally to provide a very high heating rate of up to 10 K/sec. Such a heating rate is sufficient to rapidly re-dissolve the NbAl 3 particles and enable practice of the invention.
[0037] In a typical SPS process, a powder compact is produced by pressing together a suitable mixture of the desired elemental or alloy powders, ranging in size from 3 to 50 micrometers, in a shaped die. A separate compacting die may be employed or the SPS die may be used. For the SPS process a graphite die coated with a suitable high-temperature, anti-stick material such as boron nitride (BN) is used. Once placed in the SPS die the powder compact is heated by passing a pulsed electric current in the range of from about 1000 Amp to about 5000 Amp while under an applied force which may range from about 5 kN to 200 kN. The electric current causes a rapid heating of the powder compact promoting heating rates up to 600° C./minute. A preset temperature which may range from 700° C. to 1600° C. is maintained for a suitable period to promote rapid sintering, densification and homogenization of the compact. Suitable sintering times may range from between a few seconds to a few hours and may be established based on trials or modeling for specific materials and process parameters.
[0038] Other sintering processes employing rapid heating such as by means of a laser beam, an infrared beam or induction heating, if capable of achieving rapid heating rates, may also be suitable. Suitably such rapid heating rates may range from about 5K per second to about 20K per second.
[0039] The above descriptions of embodiments of the invention are intended to illustrate the invention and not intended to limit the claimed scope of the invention.
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A process for fabricating sintered, substantially pore-free titanium aluminide articles with minor alloying element additions is disclosed. Such articles may find application as automobile engine valves and connecting rods and may be fabricated by rapidly sintering intimately mixed powders of substantially pure titanium and rapidly-cooled particles of aluminum alloyed with the minor alloying element(s).
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to French Patent Application No. 1360691 filed Oct. 31, 2013, the disclosure of which is hereby incorporated in its entirety by reference.
[0002] 1. Field of the Invention
[0003] The present invention relates to an electric household appliance with a steam generating base connected by a steam line to a tool such as a crease removing head for the vertical removal of creases from linens, and relates more particularly to an appliance with at least one rod for hanging a garment, the rod being supported by a single pole extending upwards from the base and capable of occupying a work position in which the rod is disposed transversely to the pole.
[0004] 2. Description of Related Art
[0005] U.S. Pat. No. 7,516,565 discloses an appliance with a steam generating base connected by a steam line to a crease removing head, wherein the appliance has a pole which extends vertically from the base and which has a top end bearing a transverse rod on which a clothes hanger can be hung.
[0006] Such an appliance has the advantage of enabling the removal of creases from a shirt by putting the latter on the clothes hanger hung from the transverse rod and then moving the crease removing head vertically over the shirt.
[0007] However, when the clothes hanger is hung from such a suspension rod, it is obviously placed crosswise in relation to the latter, in a position in which the vertical pole is disposed behind the garment to be ironed. The presence of the vertical pole behind the garment thus interferes with the user when the latter wishes to smooth the backside of the garment. Furthermore, when the crease removing head exerts pressure on the garment, the latter moves back against the vertical pole, which can then hinder the user in manipulating the head and crease the garment.
[0008] Hence an object of the present invention is to propose an appliance equipped with a clothes suspension device that makes it possible to solve these problems and which is easily and cost effectively implemented.
SUMMARY OF THE INVENTION
[0009] To this end, the invention has as an object an electric household appliance with a steam generating base connected by a steam line to a tool such as a crease removing head for the vertical removal of creases from linens, the appliance having at least one rod for hanging an article to be ironed, the rod being supported by a single pole extending upwards from the base and capable of occupying a work position in which the rod is disposed transversely to the pole, characterized in that in the work position, the rod extends from just one side of the pole and over a length greater than 25 cm.
[0010] Such a feature makes it possible to hang a cloths hanger, which typically has a width of around 40 cm, on one end of the rod in a position in which the hanger can pivot about its hook without coming into contact with the pole. Thus the pole no longer constitutes a hindrance to the ironing operation, as the hanger can be advantageously positioned parallel to the rod so as to allow totally free access to the back and to the front of the garment, the pole thus being disposed on one side of the garment to be ironed.
[0011] According to another feature of the invention, the pole is eccentrically disposed on the base.
[0012] Such an eccentric pole has the advantage of not taking up the center space above the base.
[0013] According to another feature of the invention, in the work position the rod extends horizontally above the base.
[0014] Such a feature makes it possible to obtain better stability of the appliance, greater compactness, and better ergonomics.
[0015] According to another feature of the invention, the rod has a length of around 40 cm.
[0016] Such a length makes it possible to have a rod corresponding essentially to the length of a clothes hanger.
[0017] According to another feature of the invention, the rod has an end which is fastened to the pole by means of a fastening device comprising a pivot joint and locking means which enable the pivot joint to be fixed in the position corresponding to the work position of the rod, the pivot joint allowing the rod to be moved from the work position to a storage position in which the rod is disposed alongside the pole.
[0018] Such a feature makes it possible to obtain greater compactness of the appliance in the storage position.
[0019] According to still another feature of the invention, the fastening device has a holder opposite the rod for resting the tool.
[0020] According to another feature of the invention, the rod is detachably connected to the pole.
[0021] Such a feature has the advantage of allowing the rod to be dismantled for greater compactness, notably when packaging the appliance in a box.
[0022] According to another feature of the invention, the rod has at least one clip for securing the article to be smoothed.
[0023] Such a feature makes it possible to remove the creases from an article such as a pair of pants or a curtain by hanging the latter vertically from the rod by means of the clips.
[0024] According to another feature of the invention, the rod has a suspension tab with a shape suitable for ensuring that the hook of a clothes hanger is held in a plane parallel to the suspension rod.
[0025] Such a holding of the hanger in a plane parallel to the rod makes it possible to ensure that the garment to be ironed is oriented parallel to the rod for better access to the back and front sides of the garment during ironing.
[0026] According to another feature of the invention, the suspension tab has the shape of a half-moon.
[0027] According to another feature of the invention, the device has a top rod disposed near the top end of the pole and a bottom rod disposed near the base.
[0028] According to another feature of the invention, the bottom rod bears two upwardly oriented clips and the top rod bears two downwardly oriented clips.
[0029] Such a feature makes it possible to hook the rod to the bottom portion of the article to be ironed, in order to exert tension on the latter for ensuring a better hold and facilitating the removal of creases therefrom.
[0030] According to another feature of the invention, the bottom rod is fastened onto the pole by means of a spring clip, the bottom rod capable of being moved vertically on the pole by exerting pressure on a hand lever of the clip.
[0031] Such a feature allows the user to adjust the position of the bottom rod according to the size of the garment to be ironed and allows a slight traction to be exerted on the garment to be ironed.
[0032] According to another feature of the invention, the pole is a telescopic pole.
[0033] Such a feature makes it possible to adjust the height of the pole and thus the positioning of the top rod according to the size (height) of the user and the garment to be ironed. Such a feature also makes it possible to have a compact appliance when the pole is lowered to its minimum height for storage.
[0034] According to another feature of the invention, the pole extends vertically.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The objects, aspects, and advantages of the present invention will be more clearly understood on the basis of the following description of a particular embodiment of the invention, which is given as a non-limiting example and which refers to the appended drawings, wherein:
[0036] FIGS. 1 and 2 are perspective views of an ironing appliance comprising a device for hanging a garment according to a particular embodiment of the invention;
[0037] FIG. 3 is a perspective view of just the suspension device equipping the appliance of FIGS. 1 and 2 , in which the rods are shown in the work position and the telescopic pole in the deployed position;
[0038] FIG. 4 is another perspective view of the suspension device of FIG. 3 with the rods illustrated in the storage position;
[0039] FIG. 5 is a perspective view of the suspension device of FIGS. 3 and 4 with the telescopic pole in the collapsed position and the rods in the storage position.
DESCRIPTION OF THE INVENTION
[0040] Only the elements necessary for understanding the invention have been illustrated. To make it easier to read the drawings, the same elements have the same reference numbers from figure to figure.
[0041] FIGS. 1 and 2 illustrate a steam ironing appliance with a base 1 housing, in a manner known per se, a steam generator connected by a steam cord 2 to a crease removing head 3 , the base 1 having two wheels allowing the appliance to be moved easily by tilting the base, and a removable tank 1 A equipped with a handle for facilitating the removal thereof.
[0042] More particularly according to the invention, the appliance has a device for hanging a garment, comprising a single pole 4 extending vertically from the base 1 , wherein the pole advantageously has four telescopic segments and extends to a height of around 1.2 m when it is fully deployed.
[0043] The pole 4 is advantageously fastened onto the edge of one of the lateral faces of the base 1 and bears a top rod 5 and a bottom rod 6 having a length of around 40 cm, the top 5 and bottom 6 rods being capable of occupying a work position illustrated in FIGS. 1 through 3 , in which position they extend horizontally above the base 1 .
[0044] The top rod 5 has two elastically deformable clips 51 disposed on either side of a suspension tab 50 fastened in the middle of the top rod 5 , wherein the tab 50 and the two clips 51 are advantageously fastened onto the top rod 5 by means of clamping jaws which allow their positioning on the top rod 5 to be changed.
[0045] The suspension tab 50 preferably has a half-moon shape on which can be positioned a hook of a clothes hanger 7 , the half-moon shape ensuring that the hanger 7 is held in the plane of the top rod 5 , as illustrated in FIG. 1 .
[0046] The top rod 5 is fastened to a top end of the pole 1 [sic] by means of a fastening device 8 comprising a pivot joint 80 which allows the top rod 5 to pivot downwards into a storage position illustrated in FIGS. 4 and 5 , in which the top rod 5 is disposed vertically alongside the pole 4 . The fastening device 8 of the top rod 5 is advantageously secured in a detachable manner to the top end of the pole and comprises locking means consisting of a wing nut 81 making it possible to fix the top rod in the work position or in the storage position, the fastening device 8 comprising a U-shaped holder 82 opposite the top rod 5 for resting the crease removing head 3 .
[0047] The bottom rod 6 has two elastically deformable clips 60 capable of being moved laterally along the bottom rod 6 , and it is fastened onto the pole 4 by means of a fastening device comprising a clip 9 brought into a closed position by a spring, wherein the clip 9 can be opened by pressing on a hand lever 92 in order to move the fastening device along the pole 4 , the actuation of the hand lever 92 also allowing the bottom rod 6 to be removed from the pole 4 .
[0048] Advantageously, the fastening device of the bottom rod 6 also has a pivot joint 90 allowing the bottom rod to pivot upward into a storage position illustrated in FIGS. 4 and 5 , in which the bottom bar 6 is disposed vertically alongside the pole 4 . Just like the one for the top rod 5 , this fastening device has locking means consisting of a wing nut 91 (only visible in FIG. 5 ), allowing the bottom rod 6 to be fixed in the work position or in the storage position.
[0049] The functioning and the advantages procured by the appliance thus configured will now be described.
[0050] When the user wishes to iron, he or she positions the bottom 6 and top 5 rods horizontally as illustrated in FIGS. 1 , 2 , and 3 and then puts the article to be ironed on the hanger 7 hung on the suspension tab 50 , if the article is a shirt, or he or she secures the article between the clips 51 , 60 of the top and bottom rods in such a way that the article is held under slight tension, if the article is a pair of pants or a curtain.
[0051] The user now turns on the steam generator and then takes the crease removing head 3 to apply steam by moving the crease removing head 3 vertically over the article to be ironed.
[0052] During this vertical movement of the head 3 , the user can smooth both sides of the article without interference from the pole 1 [sic], which saves time and procures greater ease of use. Furthermore, the article is able to recede under the pressure exerted by the head without any obstacle hindering the movement of the crease removing head 3 .
[0053] The appliance equipped with such a suspension device thus has the advantage of procuring excellent ergonomics by minimizing hindrance from the vertical pole.
[0054] When the user has finished the ironing session, he or she can reduce the bulk of the appliance by loosening the wing nuts 81 , 91 of the fastening devices of the bottom 6 and top 5 rods in order to swing the bottom 6 and top 5 rods into their storage position, as illustrated in FIG. 4 .
[0055] The user also has the option of making the appliance even more compact in both height and width by collapsing the telescopic pole 1 and by pivoting the bottom rod 6 180° on the pole 1 before swinging the bottom 6 and top 5 rods into their storage position, as illustrated in FIG. 5 .
[0056] The appliance thus configured therefore has a suspension device exhibiting the advantage of being extremely compact in the folded position.
[0057] Obviously the invention is not limited in any way to the embodiment described and illustrated herein, which was only given as an example. Modifications are still possible, notably in terms of the constitution of the various elements or by substituting equivalent techniques, without in any way exceeding the scope of protection of the invention.
[0058] Hence in an alternate embodiment not shown, the pole could be made in a single piece.
[0059] Hence in another alternate embodiment not shown, the bottom and top rods could be telescopic.
[0060] In still another alternate embodiment not shown, the suspension tab in the shape of a half-moon for holding the hanger could be replaced with a suspension tab equipped with a hole for inserting the hook of the hanger.
[0061] In another alternate embodiment not shown, the bottom and top rods could be detachably fastened to the pole and occupy just the work position when they are fastened to the pole.
[0062] In another variant not shown, the crease removing tool is a clothes iron.
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Electric household appliance comprising a steam generating base ( 1 ) connected by a steam line ( 2 ) to a tool ( 3 ) such as a crease removing head for the vertical removal of creases from linens, the appliance having at least one rod ( 5, 6 ) for the suspension of an article to be ironed, the rod ( 5, 6 ) being supported by a single pole ( 4 ) extending upwards from the base ( 1 ) and capable of occupying a work position in which the rod ( 5, 6 ) is disposed transversely to the pole ( 4 ), characterized in that the rod ( 5, 6 ) in the work position extends from just one side of the pole ( 4 ) and over a length greater than 25 cm.
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TECHNICAL FIELD
[0001] The present application relates generally to wireless communications systems and, more specifically, to procedures for assigning initial access rights to DM servers upon successful completion of the DM bootstrapping procedure.
BACKGROUND
[0002] Each device that supports Open Mobile Alliance (OMA)-Device Management (DM) contains a Management Tree. The DM client resident on the device must expose the Management Tree to previously bootstrapped DM servers. The Management Tree organizes all available Management Objects in the device as a hierarchical tree structure where all nodes can be uniquely addressed with a Uniform Resource Identifier (URI). The OMA-DM specifications provide the following guidelines for the ACL (Access Control List) value of the root of the Management Tree.
The default value for the root ACL SHOULD be Add=*&Get=*. To ensure that any authenticated server always can extend the Management Tree, the root ACL value for the Add command SHOULD NOT be changed.
[0004] A consequence of the above listed requirement is that when a device is bootstrapped to a new DM server, by default, the new DM server is able to see all the direct nodes of the root of the Management Tree. In addition, the new DM server can create its own sub-tree under the root. By reading the ACL value of the root node, the new DM server is able to obtain the Server IDs of other bootstrapped DM servers, presenting a potential security risk in the case where multiple management authorities are involved. These problems had been masked by the fact that, prior to DM 1.3, most devices were managed by only one DM server.
SUMMARY
[0005] A client device for use in a wireless communications network is provided. The client device includes a memory configured to store a plurality of instructions. The client device also includes processing circuitry capable of being configured to assign the default access rights to a DM server, upon successful completion of a bootstrap.
[0006] A server device for use in a wireless communications network is provided. The server device includes a memory configured to store a plurality of instructions. The server device also includes processing circuitry capable of configuring default access rights to a device management (DM) server on a device upon successful completion of a bootstrap procedure.
[0007] A method for use in a wireless communications network is provided. The method includes storing a plurality of instructions. The method also includes assigning default access rights to a DM server, upon successful completion of a bootstrap procedure.
[0008] Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:
[0010] FIG. 1 illustrates an OMA-DM transaction model according to this disclosure;
[0011] FIG. 2 illustrates a Management Tree according to this disclosure;
[0012] FIG. 3 illustrates a network topology view of the Device Management System according to embodiments of the present disclosure;
[0013] FIG. 4 illustrates the OMA-DM architecture according to embodiments of the present disclosure;
[0014] FIG. 5 illustrates a structure of a Bootstrap Config Management Object (MO) according to the present disclosure; and
[0015] FIG. 6 illustrates additional nodes for the Bootstrap Config MO according to embodiments of the present disclosure.
DETAILED DESCRIPTION
[0016] FIGS. 1 through 6 , discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged wireless communications system.
[0017] OMA-DM is a secure two-way management protocol that runs between a DM server 105 and a DM client 110 and it is used for remote management of devices. Historically the devices have been wireless devices; however OMA-DM has also started to address the remote management needs of wired devices. The OMA-DM protocol runs within the context of a DM session, using a request/response transaction model. Once a DM session is established, the DM server alternately sends commands to the Client and receives responses from the Client. The Client also informs the Sever about events that have occurred on the device, via Generic Alerts. The Management includes: Setting initial configuration information in devices; Subsequent installation and updates of persistent information in devices; Retrieval of management information from devices; Processing events and alarms generated by devices.
[0018] FIG. 1 illustrates an OMA-DM transaction model according to this disclosure. The embodiment of the OMA-DM transaction model 100 shown in FIG. 1 is for illustration only. Other embodiments could be used without departing from the scope of this disclosure.
[0019] A DM session consists of two phases: the setup phase followed by the management phase. The setup phase entails authentication and device information exchange.
[0020] OMA-DM supports the notion of Packages. A Package is a collection of related messages that are transferred between an originator and a recipient. Generally a Package consists of a single message. However, in cases where the information to be transferred between the originator and the recipient exceeds the size limitation of a DM message, the information can be sent over multiple messages within the same Package. Each message in a Package has to be responded to individually.
[0021] DM sessions are always initiated by the DM client. However, a Server can trigger the Client to initiate a session by sending an unsolicited message, known as the DM Notification, to the Client. The DM Notification “wakes up” the device and causes it to initiate a session with the requesting DM server. This message can be delivered over a variety of transports including SMS, HTTP and SIP.
[0022] In the setup phase, the DM server 105 sends an alert in package- 0 115 to the client 110 . The DM client 110 responds with package- 1 120 , which includes a client initialization with client credentials and device information. In response, the DM server 105 sends package- 2 125 : server initialization with server credentials, initial management operations or user interaction commands from the server. During the management phase, the DM server 105 issues commands which are processed by the DM client 110 . The DM client 110 sends package- 3 130 : direct response to server management operations. The DM client 110 provides the status of the commands issued as well as any response that may be needed. The DM server 105 responds with package- 4 135 : more user interaction and management operations if the session is continued.
[0023] Normally a DM session ends when the DM server 105 sends an empty message (i.e. a message that does not contain any management operations or authentication challenges) to the DM client 110 . However, either the DM client 110 or the DM server 105 can abort the session at any time.
[0024] With the exception of Package- 0 115 , all messages exchanged between the DM client 110 and the DM server 105 are Synchronization Markup Language (SyncML) messages. Conversely, Package- 0 115 is a specially formatted binary message that is sent from the DM server 105 to the DM client 110 . This message contains the DM server ID and it causes the DM client 110 to initiate a management session with the DM server 105 .
[0025] The OMA-DM protocol supports DM Bootstrapping. Bootstrapping is the process by which a device moves from an un-provisioned, empty state, to a state where it is able to initiate a management session with authorized DM servers. DM clients 110 that have already been bootstrapped can be further bootstrapped to enable the device to initiate a management session to new DM servers 105 .
[0026] OMA-DM defines various ways to perform the bootstrap process that include:
[0027] 1) Customized bootstrap in which Devices are loaded with OMA DM account and connectivity information at manufacture, which is also referred to as factory bootstrap;
[0028] 2) Bootstrap from smartcard in which the smartcard is inserted in the device and the DM client 110 is bootstrapped from the smartcard;
[0029] 3) Over The Air bootstrap (aka Server initiated bootstrap) in which the DM server 105 sends out Bootstrap Message via some push mechanism, e.g. WAP Push or OBEX. The DM server 105 needs to receive the device address/phone number beforehand;
[0030] 4) Client initiated bootstrap, over a secure HyperText Transfer Protocol (HTTPS).
[0031] FIG. 2 illustrates a Management Tree according to this disclosure. The embodiment of the Management Tree 200 shown in FIG. 2 is for illustration only. Other embodiments could be used without departing from the scope of this disclosure.
[0032] To access the xyzInc node in the Management Tree 200 , a server can present the address: ./DMAcc/xyzInc, or DMAcc/xyzInc. A Uniform Resource Indicator (URI) used in OMA DM can be case sensitive and node names are chosen such that resulting URI strings differ in more than just the case of individual letters. Implementations, even if treating and interpreting URIs as case insensitive, preserve the case of symbols in the names of dynamically created nodes.
[0033] Nodes are the entities that can be manipulated by management actions carried over the OMA DM protocol. A node can be as small as an integer or large and complex like a background picture or screen saver. The OMA DM protocol is agnostic about the contents, or values, of the nodes and treats the Leaf node values as opaque data.
[0034] An Interior node can have an unlimited number of child nodes linked to it. The complete collection of all nodes in a management database forms the tree 200 structure. Each node in the tree 200 has a unique URI and each node has properties associated with it. Table 1 illustrates example node properties and Table 2 illustrates support for the node properties. All properties, except the ACL, are valid only for the node to which they are associated.
[0000]
TABLE 1
NODE PROPERTIES
Property
Explanation
ACL
Access Control List.
Format
Specifies how node values should be interpreted.
Name
The name of the node in the tree.
Size
Size of the node value in bytes.
Title
Human readable name.
TStamp
Time stamp, date, and time of last change.
Type
The MIME type of a Leaf node's value or a URN
representing the Management Object identifier for
Interior nodes that root a Management Object sub-
tree.
VerNo
Version number, automatically incremented at each
modification.
[0000]
TABLE 2
SUPPORTED NODE PROPERTIES
Property
Device Support
ACL
MUST
Format
MUST
Name
MUST
Size
MAY for Leaf nodes;
MUST NOT for Interior nodes
Title
MAY
TStamp
MAY
Type
MUST
VerNo
MAY
[0035] The ACL property has some unique characteristics when compared to the other properties. The access rights granted by an ACL are granted to Server Identifiers and not to the URI, IP address, or certificate of the DM server 105 . The Server Identifier is an OMA DM specific name for a server. A Management Session is associated with a DM server Identifier through OMA DM authentication. All management commands received in one session are assumed to originate from the same DM server 105 .
[0036] nodes in the Management Tree 200 can be either permanent or dynamic. Permanent nodes are typically built in at device manufacture. Permanent nodes can also be temporarily added to a device by, for instance, connecting new accessory hardware. However, the DM server 105 cannot create or delete permanent nodes at run-time. An attempt by a DM server 105 to delete a permanent node will return status Command not allowed. The same status code will also be returned for all attempts to modify the Name property of a permanent node. Dynamic nodes can be created and deleted at run-time by DM servers 105 . The Add command is used to create new nodes. The Delete command is used to delete Dynamic nodes and all their properties. If a deleted node has children, i.e., is an Interior node, the children are also deleted. A permanent node can be the child of either a dynamic or a permanent node. In such cases, the permanent child node is created at the same time its parent node is created. The complete layout of the permanent nodes in the Management Tree 200 is reflected in the device description.
[0037] The complete structure of all nodes and the root (the device itself) forms the tree 200 . nodes with the Format property set to node are defined as Interior nodes. nodes that are not Interior nodes are defined as Leaf nodes. Interior nodes can have 0 or more children; Leaf nodes cannot have children. DM servers 105 can explore the structure of the tree 200 by using the GET command. If the accessed node is an Interior node, a list of all child node names for which the requesting DM server 105 has the Get access is returned. If the Interior node has no children, an empty list of child node names is returned, e.g., <Data/>. If the node is a Leaf node it must have a value, which could be null, and this value is returned.
[0038] The Management Tree 200 can be extended at run-time. This is done with the Add or Replace command and both new Interior nodes and new Leaf nodes can be created. The parent of any new node is an Interior node. The device itself can also extend the Management Tree 200 . This could happen as a result of user input or by attaching some kind of accessory to the device.
[0039] FIG. 3 illustrates a network topology view of the Device Management System according to embodiments of the present disclosure. The embodiment of the network 300 shown in FIG. 3 is for illustration only. Other embodiments could be used without departing from the scope of this disclosure.
[0040] The network 300 includes a wireless device 305 coupled to the DM server 310 through one or more of: a cellular network 315 and the Internet 320 . In addition, a wired device 325 is coupled to the DM server 310 through the Internet 320 . Target devices, such as wireless device 305 and wired device 325 , include a memory configured to store instructions to execute processes for running the OMA-DM protocols and processing circuitry configured to execute the instructions and operate as a DM client. For example, the memory can store information regarding the tree, additional nodes and Table 3 described herein below. The DM server 310 includes a memory configured to store instructions to execute processes for running the OMA-DM protocols and processing circuitry configured to execute the instructions. The network 300 also includes an operations support system (OSS) 330 , which is configured to perform the functions of a management authority. In the example shown in FIG. 3 , solid lines represent physical connectivity and dotted lines represent logical connectivity. The DM protocol runs between the DM server 310 and the wireless device 305 in the Cellular Network 315 & between the DM server 310 and the wired device 325 connected to the Internet 320 . The OSS 330 directs the device management operations on the target devices (e.g., wireless device 305 and wired device 325 ) via the DM server 310 . Only the interaction between the DM server 310 and the DM client, which resides on the target devices (e.g., wireless device 305 and wired device 325 ), is within the scope of the OMA-DM specification.
[0041] The DM protocol defines three standard Management Objects (MOs) that all implementations support as described in OMA Device Management Standardized Objects—6 Mar. 2012, Open Mobile Alliance, OMA-TS-DM StdObj-V1 — 3-20120306-C., (“StdObj Specification”) the contents of which are hereby incorporated by reference in their entirety. These are DMAcc (DM Account), DevInfo (Device Information) and DevDetail (Device Details).
[0042] The DMAcc MO is used to manage information pertaining to the bootstrapped DM servers. For each server that has been successfully bootstrapped for the device, the DMAcc MO maintains the following information (among other things):
[0043] DM server ID;
[0044] Connectivity information;
[0045] Server address; and
[0046] Server and client credentials.
[0047] The DevInfo MO provides basic information about the device. This includes:
[0048] Device ID;
[0049] Device manufacturer ID;
[0050] Model identifier; and
[0051] Language setting.
[0052] The DevDetail MO provides additional information about the device. This includes:
[0053] Device type;
[0054] Original Equipment Manufacturer;
[0055] Hardware version;
[0056] Firmware version;
[0057] Software version;
[0058] Indication whether the device supports optional features (e.g. large-object handling capability);
[0059] Maximum depth of the Management Tree;
[0060] Maximum total length of any URI;
[0061] Maximum total length of any URI segment FIG. 4 illustrates the OMA-DM architecture according to embodiments of the present disclosure. The embodiment of the OMA-DM architecture 400 shown in FIG. 4 is for illustration only. Other embodiments could be used without departing from the scope of this disclosure. FIG. 4 describes the main entities in the OMA-DM System and identifies the major interfaces between them.
[0062] The OMA-DM architecture 400 manages aspects of the target device, such as wireless device 305 or wired device 325 , and the server 310 . The OMA-DM architecture 400 includes a DM enabler 405 , which interfaces with other management objects 410 , smart cards 415 , OTA provisioning servers 420 , Client Provisioning (CP) enabler 425 and the Device Management Authority 430 . Aspects of the DM enabler 405 include the DM client 435 , DM server 440 , DM standard objects 445 and a Device Management Application Characteristic (DM AC) 450 . A solid line indicates that the DM enabler 405 uses functions of another component. For example, the DM client 435 uses DM-1 client-server notification from DM server 440 ; the DM client 435 and DM server 440 exchange the exchange protocol messages; the DM client 435 gets bootstrapped to the DM server 440 via various means, such as by the smart card 415 , the OTA provisioning server 420 or the CP enabler 425 . The dashed lines indicate interfaces outside the scope of the DM enabler 405 .
[0063] FIG. 5 illustrates a structure of a Bootstrap Config Management Object (MO) according to the present disclosure. The Bootstrap Config MO 500 shown in FIG. 5 is for illustration only. Other embodiments could be used without departing from the scope of this disclosure.
[0064] Embodiments of the present disclosure alter the default access rights for newly bootstrapped DM servers. According to embodiments of the present disclosure, the default access rights for newly bootstrapped DM servers are brought under management control by adding new nodes to the Bootstrap Config MO 500 . The Bootstrap Config MO 500 includes a MO root node 505 , a BootSrvDiscovery node 510 , a BootSrvInfo node 515 and an Ext node 520 . The BootSrvInfo node 515 further includes a placeholder node 525 , Uniform Resource Locator (URL) 530 and Ext node 535 .
[0065] FIG. 6 illustrates additional nodes for the Bootstrap Config MO according to embodiments of the present disclosure. The embodiment of the additional nodes 600 shown in FIG. 6 is for illustration only. Other embodiments could be used without departing from the scope of this disclosure.
[0066] In certain embodiments, the Bootstrap Config MO 500 is enhanced by adding the following nodes under the BootSrvInfo/<x> node 515 : AccessRights node 605 , a placeholder node 610 , a SubtreeURI node 615 and an AccessCode node 620 . In certain embodiments, the AccessRights node 605 is added under the MO root node 505 .
[0067] The . . . /AccessRights 605 is an interior node that is the root node for all access rights information. If the AccessRights node 605 is not present, the initial ACL access rights are assumed to be as per the device policy. That is, the AccessRights node 605 is configured to indicate device specific rights as opposed to universal default rights. The device specific rights apply to all future DM servers to which the device is bootstrapped.
[0068] The . . . /AccessRights/<x> 610 is the root node for access rights information for one subtree within the Management Tree 200 .
[0069] The . . . /AccessRights/<x>/SubtreeURI stores a URI value. The value of this leaf node is the URI of the root of a subtree within the Management Tree 200 .
[0070] The . . . /AccessRights/<x>/AccessCode 620 stores a value associated with DM access rights. That is, the value of this leaf node (AccessCode node 620 ) indicates the DM access rights for the subtree which is rooted at the node whose URI is the value of the sibling SubtreeURI node. The valid value of this node is any value from Table 3, or any value obtained from the bit-wise ORing of the values in Table 3:
[0000]
TABLE 3
Access Type
Value
Get
1 (i.e. 0x1)
Replace
2 (i.e. 0x2)
Exec
4 (i.e. 0x4)
Copy
8 (i.e. 0x8)
Add
16 (i.e. 0x10)
Delete
32 (i.e. 0x20)
[0071] For example, if the ACL rights are only Get, the value of the AccessCode node 620 is “1”. If the ACL rights are Get, Add and Delete, the value of the AccessCode node 620 is “49” (that is 1+16+32).
[0072] Addition of these nodes 600 to the Bootstrap Config MO 500 allows management authorities to manage the default access rights assigned to a DM server when the device is bootstrapped to the DM server. The management authorities can restrict the access rights of the DM server at either a subtree or an individual node level. Unlike the conventional case (i.e. prior to the additional nodes 600 illustrated by embodiments of the present disclosure), management authorities do not have to give blanket access for retrieval and new node addition at the Management Tree root level. Additionally, the management authorities can proscribe specialized access rights for different subtrees based on variations in the additional nodes.
[0073] Although the present disclosure has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.
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A client device and a server device communicate using an Open Mobile Alliance (OMA)-Device Management (DM) protocol. The client device is configured to grant the desired access rights to a newly bootstrapped DM server, upon successful completion of a bootstrap procedure, by using nodes in the Bootstrap Config Management Object (MO) to specify the access rights for different portions of the Management Tree.
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CROSS REFERENCE TO RELATED APPLICATIONS
This patent application is a continuation of application Ser. No. 09/711,191 filed Nov. 13, 2000 now U.S. Pat. No. 6,647,918, which is a divisional of application Ser. No. 09/111,251 filed Jul. 3, 1998, now U.S. Pat. No. 6,192,827.
FIELD OF THE INVENTION
This invention relates to the construction of vacuum processing chambers used in processing of substrates for deposition and removal of materials. A particular chamber configuration using a specialized liner is disclosed.
BACKGROUND OF THE INVENTION
In general, vacuum processing chambers for processing substrates include a substrate transfer opening, commonly known as a slit valve. A slit passage associated with the slit valve is commonly used to transfer substrates into and out of the processing chamber between processing cycles. Commonly a robot extends from a cluster tool through a slit valve opening through the slit valve passage to deliver or remove a substrate to be processed to or from a processing location in the vacuum processing chamber. Once the substrate transfer at the substrate processing location is complete, the robot is retracted through the slit valve opening and back into the cluster tool. The slit valve opening is commonly sealed at an outside surface of the chamber body by a blocking plate which moves over the slit valve opening, in a coordinated motion with the movement of the robot and substrate into and out of the processing chamber. Plasma is often used in a processing chamber to enhance the process being performed. In a typical arrangement of a vacuum processing chamber, where a plasma is utilized to initiate or enhance process activity, the processing chamber and all internal services exposed to the plasma and the chemical by products are affected and can become coated with chemical byproducts of the process being performed.
Typically, the walls of the processing chamber are at least several inches thick to provide a sturdy chamber wall for processing activity. Thus, the opening in the side of the processing chamber which allows substrates to be transferred into and out of the chamber, the slit valve passage, presents a large tunnel-like opening which creates a geometric discontinuity at the inside surface of the processing chamber. The presence of a large cavity hole (the opening of the substrate transfer passage) adjacent to the space of the central processing location allows the plasma envelope which is present during plasma processing at the substrate processing location to expand into the cavity of the slit valve passage. The expansion of the plasma envelope into the cavity of the slit valve passage creates a distortion in the portion of the plasma situated adjacent to the cavity such that the plasma flux over the substrate in the area near the slit valve passage is affected, such that the deposition or etch taking place in that area is not uniform with other areas of the substrate where such distortion is not present.
Further, the internal surfaces of the slit valve passage, including the inside (process chamber facing side) of the slit valve door, are also subject to deposition and accumulation from the chemical process taking place in the chamber. Deposition on the inside surfaces of the slit valve passage and the slit valve door, require that any cleaning of the chamber (whether wet or dry) extend to include such surfaces. A thorough cleaning of the slit valve door requires that it also be removed so that the full area of the door all the way to the sealing limit be cleaned. In most instances, door cleaning requires that the cluster tool be removed from service so that cleaning of one chamber does not cause potential contaminants from one chamber serviced by the cluster tool to be carried over into a second chamber serviced by the same cluster tool.
The heavy duty sturdy construction of the processing chamber body and its liners finds no ready solution to the problem of the open cavity resulting from the slit valve passageway. Until now there has been no solution to overcome these anomalies of prior art devices, in that all prior doors are constructed in a configuration that gives rise to particles in the processing chamber.
SUMMARY OF THE INVENTION
A configuration according to the present invention overcomes the drawbacks of the prior art by providing an internal slit passage door which is cleverly constructed to improve the plasma uniformity over the substrate processing location and prevent deposition of chemical byproducts (such as polymers) in the slit valve passage. This second “internal” slit passage door is constructed as part of the chamber liner assembly so that when the chamber liner is replaced or a wet clean of the chamber liner is performed, the door is replaced and cleaned at the same time.
One configuration according to the invention includes a chamber body enclosing a substrate processing location space. The chamber body includes a slit passage extending from an outside surface of the body to the substrate processing location space, the slit passage being sized to pass a substrate therethrough. An outer slit valve door is positioned near the outside of the substrate transfer passage to seal the outer end of the slit passage to the chamber. An inner slit passage door is positioned in an inner portion of the substrate transfer passage to block the substrate transfer slit passage at a location near of adjacent to the substrate processing location.
Another configuration according to the invention can be defined with respect to a liner surrounding a substrate processing location in the vacuum processing chamber where the liner includes a substrate transfer opening therethrough. A liner door is selectively movable from an open position where the substrate to be processed can be passed, to a closed position where the liner door is located in close proximity to, but not touching the surrounding liner around the substrate transfer opening such that the edges of the door overlap edges of the substrate transfer opening. The overlap should preferably be approximately a half inch. The gap between the door in its fully closed position and the surrounding liner is in the range of several tens of thousands of an inch (several times 0.254 mm) all around, but the door never touches the liner during operation. The door is curved to match the configuration of a curved liner, for example, a circular liner configuration. The movement of the door is vertical and selectively supported and controlled through a series of bellows which act as the vacuum limit of the processing chamber. The vertical motion limit of the door is precisely set by a set of soft stops which prevent the door from touching the liner.
To reduce the chances for particle contamination, the bottom and top portions of the door are beveled to matched opposed beveled portions of the inner liner. With such a configuration the buildup of deposited material on the inner surface of the door will not interfere with raising the door, as the clearance between the door and liner will increase with each incremental distance that the door is moved from its fully closed position towards an open position.
The invention further includes a method for reducing the buildup of process byproducts on the surfaces of a substrate transfer passage and for improving the uniformity of plasma in a vacuum processing chamber utilizing the steps of: providing a movable door to selectively block the substrate transfer passage at a location adjacent to the substrate processing location in the vacuum processing chamber, and moving the movable door out of the substrate transfer passage when a substrate is being transferred to or from the substrate processing location. The door and door support structure may be movable between a door open position and a door closed position without rubbing contact between any two items within the vacuum limits of the processing chamber.
The door is opened simultaneously with the external slit valve door to permit passage of a substrate into and out of the chamber (for example, by a robot blade). The support for the door prevents lateral movement of the door and assists in positioning it precisely in its down position against a hard stop.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a processing chamber according to the invention showing the outside of the chamber and a slit valve opening through which a substrate for processing can pass;
FIG. 2 is a partially exploded perspective view of the chamber top of FIG. 1 , the inner slit valve door and its actuator are shown separated from the top flange of the processing chamber;
FIGS. 3A and 3B are exploded perspective views of the pieces of the inner slit passage door actuator and slit valve door according to the invention;
FIG. 4 is a top view of the slit passage door and actuator mechanism according to the invention; FIG. 5 is a cross-sectional side view of a configuration of a vacuum processing chamber according to the invention showing the use of an external slit valve door and internal slit passage door in relationship to the substrate processing location of the processing chamber;
FIG. 6 is a cross-sectional view of the actuator mechanism for the internal slit passage door according to the invention with the door in an up position;
FIG. 7 is a cross-sectional view of the actuator mechanism as shown in FIG. 6 with the slit passage door according to the invention in a lower closed position;
FIGS. 8 , 9 and 10 are progressive assembly steps for moving the slit passage door into position and securing it to its actuator showing the installation steps and the clearances between the inner slit valve door according to the invention and a liner configured to receive the inner slit valve for the door;
FIG. 11 is a cross-sectional view of a slit passage door according to the invention showing the location and configuration of lift rods which connect the actuator above;
FIGS. 12 and 13 show respectively the connections between the slit passage door and the lift rods, FIG. 12 showing a fixed connection while FIG. 13 shows a floating connection; and
FIG. 14 shows a top view of the slit valve door showing the slotted opening for the floating lift rod of the door.
DETAILED DESCRIPTION
FIG. 1 shows a perspective view of a typical semiconductor wafer processing chamber 20 . A frame 22 supports a chamber body 24 . The chamber body 24 at its front side has a slit valve passage 28 with an outer slit valve door (that cannot be seen in FIG. 1 ) to seal the chamber and a chamber top assembly 26 . Adjacent to the chamber top assembly 26 is an inner slit passage door actuator assembly 30 shown with its cover removed. Note that the inner slit passage door actuator assembly 30 is on the same side of the chamber body 24 as the slit valve passage 28 and the outer slit valve door (which cannot be seen) through which wafers are passed into and out of the chamber 20 .
FIG. 2 is a partially exploded perspective view of the chamber liner and top assembly 40 including the inner slit passage door actuator assembly 30 . A chamber top plate (or flange) 42 at its center supports a top plate electrode cover 44 and on the side adjacent the slit valve passage supports the inner slit passage door actuator assembly 30 which is located by dowel holes 46 , 48 . A pair of door lift rods, the left rod being the fixed lift rod 200 and the right rod being the floating lift rod 210 pass through their respective holes in the chamber top plate 42 to fit into holes in the top of inner slit passage door 60 . As can be seen in FIG. 2 the inner slit passage door 60 is curved to match the radius of the chamber liner assembly 50 . The inner slit passage door 60 is attached to the lift rods 200 , 210 by a rod retaining screw 72 and a shoulder screw 82 , respectively. The inner slit passage door 60 fits in a slit door recess 54 in the chamber liner assembly 50 so that when the inner slit passage door 60 is in its down position, it covers and overlaps the slit opening 52 in the liner assembly 50 .
FIGS. 3A and 3B show an exploded perspective view of the parts of the inner slit passage door 60 and vertical actuator assembly 30 . A top view of the assembled actuator assembly 30 is shown in FIG. 4 , while a detailed cross-sectional view of the actuator assembly is shown in FIG. 6 . In the description that follows, all of these Figures should be referenced to thoroughly understand how the door support rods 200 , 210 support and precisely position the inner slit passage door 60 as it moves up and down.
An actuator base 100 is supported on the chamber top plate 42 (for example, as shown in FIG. 2 ). The base 100 includes a large dowel pin 186 and a small dowel pin 188 ( FIG. 6 ) which fit into large and small dowel pin holes 46 , 48 , respectively, in the chamber top plate 42 . The dowel pins fit tightly in these holes and their two different sizes prevent an incorrect installation. The lower surface of the actuator base 100 includes a set of two O-ring grooves each having an O-ring seal (e.g., 132 , 134 ) surrounding the lift rods 200 , 210 passing through openings in the bottom of the actuator based 100 . A set of two bellows mounting tubes 102 , 104 which are integral with the base 100 extend vertically from the bottom portion of the base to provide an enclosure for a set of rod lifting bellows assemblies 120 , 140 . Each rod lifting bellows assembly (e.g., 120 , 140 ) includes an intricately assembled set of pieces which guide each of the lift rods as they move up and down and restrict their sideways motion while maintaining a vacuum seal across the bellows without any rubbing parts. Each rod lifting bellows assembly (e.g., 120 , 140 ) includes a bellows central rod 128 which extends from a top of the assembly all the way through to its bottom. At the bottom of the assembly, a lower rod receiving portion 121 includes a threaded hole for receiving an upper end (e.g., 202 ) of one of the door lift rods (e.g., 200 , 210 ). The lower portion 121 of the central rod 128 extends down below a lower bellows flange 122 that extends laterally outward from the central rod 128 . At the perimeter of the lower bellows flange 122 , a cylindrical set of corrugations form a cylindrical bellows attached to the perimeter of the flange 121 . The upper end of the cylindrical bellows 123 is welded to an upper bellows flange 124 . The perimeter of the upper bellows flange 124 extends out over the end of the top of the bellows mounting tube 102 and includes a downwardly facing inner recess to fit over a raised inner ledge/seal flange 114 ( FIG. 3A ) of the bellows mounting tube 102 , against which a sealing O-ring 106 is positioned. The bellows flange 124 at its center includes an upwardly extending guide bearing support tube 126 . A tightly fitting lower rod guide bearing 125 is supported at a lower end of the guide bearing support tube 126 , while an upper bellows rod guide bearing 127 is supported at an upper portion of the tube. A travel stop tube assembly 150 includes a lower flange 152 and a tube portion 154 . The lower flange 152 sits on and seats against the upper bellows flange 124 and the upper surface of the bellows mounting tube 102 . The travel stop tube assembly 150 surrounds the guide bearing support tube 126 . The tube portion 154 of the travel stop assembly 150 extends to a tube end 158 which has an O-ring groove 156 . An O-ring 168 is placed in the O-ring groove 156 and acts as a bumper to dampen the shock of stopping when the actuator assembly moves down and contacts the end 158 of the travel stop tube assembly 150 . The travel stop tube assembly 150 acts as a hard stop to prevent further downward motion of the inner slit passage door 60 .
The upper end of the bellows central rod (e.g., 128 ) is connected to a floating joint 174 which restricts vertical motion (Z-axis) but allows X-Y axis motion and also angular (spherical-type tilting) between the two halves of the joint. This floating joint allows for minor misalignments without creating any binding forces that might prevent an easily operable vertical stroke.
At the bottom end of the bellows central rod 128 a top end of the fixed lift rod 200 includes a threaded portion which is threaded into the hole in the lower portion of the bellows central rod 121 and also includes a flange which acts as a stop to tightly control the overall vertical dimension of the fixed lift rod 200 with respect to the bellows central rod 128 . The flange contributes to achieving the tight tolerance in vertical positioning (spacing) that is very important in this configuration so that a specified gap between parts is maintained, but touching of such parts does not occur. In the configuration as shown, the lower portions of the two central rods shown, as will be discussed in detail later, are fixed to the inner slit passage door 60 by the fixed screw 72 and the shoulder screw 82 .
Compared to the left side rod lifting bellows assembly 120 described above, the right side rod lifting bellows assembly 140 contains identical components and is sealed to a right side seal flange 116 by an O-ring 108 ( FIG. 3A ). The top end of the right side rod lifting bellows assembly 140 is also enclosed by a travel stop tube assembly 160 which contains an O-ring bumper 170 at its top surface and the central bellows rod of the right side (floating side) can connect to a right-side floating joint 176 .
The two floating joints 174 , 176 are connected at their top ends to a rod lift cross member 180 which is rigidly fixed to the pneumatic actuator rod 112 of a pneumatic actuator cylinder contained in a pneumatic actuator base 110 by a pneumatic actuator connection bolt 182 . The limit of the upward vertical motion is set by the limit on the pneumatic actuator 110 and the motion limits of the pneumatic rod 112 . High pressure air (for example, 60 to 80 psi (0.414 to 0.551 MPa)) is commonly used to move the actuator up or down as required. With such high pressure, the force will be fast acting and the rigidity of the pneumatic actuator rod 112 along with its tight clamping to the rod lift cross member 180 along with the use of floating joints 174 and 176 prevents there from being any binding as a result of the door lift rods or the bellows central rods being out of alignment with the pneumatic actuator 112 .
FIG. 6 pictures the fully up position of the inner slit passage door 60 positioned above the top edge of the slit opening 52 in the liner assembly 50 .
FIG. 7 shows the same elements of the actuator assembly as in FIG. 6 but the inner slit passage door 60 is shown in its lowered position and the positions of all actuator elements correspond to their positions when the rod lift cross member 180 contacts the tops of each of the travel tube assemblies 150 , 160 to prevent the door 60 from descending further. In this configuration is can be seen that the inner slit passage door 60 overlaps the edges of the slit opening in liner 52 by an equal amount all around of approximately one half inch.
The vacuum limits of the processing chamber extend into the actuator assembly. The O-rings 132 , 134 which the seal the bottom of the actuator base 100 against the top of the chambered top plate 42 provide one seal. A second seal is provided by the O-rings 106 , 108 configured between the upper bellows flanges (e.g., 124 ) and the top end flange/lip 114 of the bellows mounting tube 102 ( FIG. 3A ). The cylindrical bellows corrugation (e.g., 123 ) which is welded between the lower bellows flange 122 and the upper bellows flange 124 completes the sealing/separation between the atmosphere and vacuum while still allowing the actual vertical movement without their being any particles generated as a result of rubbing two pieces within the vacuum chamber. The guiding of the central rod (e.g., 128 ) by the linear guide bearings (e.g., 125 , 127 ) in the bellows assembly is located in atmosphere and particles thus generated have no effect on processing within the vacuum chamber.
An element of the proper location of the inner slit passage door 60 and its movement are the tight dimensional tolerances specified for the base 100 . The use of an integral large base which is dimensioned and toleranced very tightly (several thousands of an inch in most instances) assures that appropriate dimensional relationships between the inner slit passage door 60 and the adjacent liner assembly 50 are maintained.
FIG. 4 , a top view, shows the curved configuration of the inner slit passage door 60 with respect to the two rod lifting axes of the bellows assemblies 120 , 140 as positioned on the base 100 of the actuator assembly 30 .
FIG. 5 shows an elevational cross sectional view of a processing chamber with a substrate processing location 220 being located opposite a substrate transfer passage 222 such that a slit valve door 224 at the outside of the passage and the inner slit passage door 60 obstruct the passage of a substrate from the outside of the chamber to the substrate processing location 220 . The slit passage actuator assembly 30 is located above the inner slit passage door 60 (some internal elements of the actuator assembly are not shown in this view).
FIGS. 8 , 9 , and 10 show the progressive installation sequence of the door 60 using cross sectional views along the vertical hole passages through the door which mate with the door lift rods 200 , 210 . In FIG. 8 , the lift rod 210 is shown in a retracted (up) position with respect to the chamber top plate 42 .
The inner slit passage door 60 has a lower counterbore bolt hole 61 , a narrow pass through hole 63 and a top rod receiving hole 65 . During assembly, the inner slit passage door 60 is moved into position under the door lift rods in the liner assembly 50 . The construction of the inner slit passage door 60 is such that the thickness of the door, (more particularly the position of its front face) changes from top to bottom such that there is a lower beveled face 62 at the bottom portion of the slit passage door 60 , there is uniform thickness face area 64 (which here is shown straight (i.e., vertical), but in an alternate configuration may be may be slightly angled or beveled) and an upper beveled face 66 where the thickness of the door increases towards the top. The beveled faces match lower 84 and upper 86 beveled faces on the liner inner wall portions 94 , 96 such that when in position as shown in FIG. 10 , the gaps (e.g., 88 , 90 ) between the front faces ( 62 , 66 ) of the inner slit passage door 60 and the facing liner upper and lower surfaces ( 84 , 86 ) are approximately several tens of thousandths of an inch (several times 0.254 mm).
The gap dimensions (e.g., 88 , 90 ) are maintained to prevent any plasma (and processing byproducts such as polymers) from moving into the substrate transfer passage 222 as it does in the prior art. Further this gap is large enough so that the risk of the door touching (rubbing against) the liner during operation is minimized so that particles are not created, but the gap is tight enough so that plasma is choked and chemical byproducts (byproducts of the processing which tend to coat the surface of the processing chamber facing it) cannot pass through. Further build up of films which do deposit on the surface of the inner passage door 60 have a minimal effect in that the bevels on the face of the liner and the matching top and bottom and partial beveled surfaces bevel in the slit valve door mean that the closest approach between the liner and the door is when it is in a fully closed position. As soon as there is any motion to the open position, the gap, for example as shown in FIG. 9 and 10 , gap dimension 90 in FIG. 10 increases tremendously to become gap dimension 92 in FIG. 9 .
FIG. 3B shows in a perspective view the beveled orientations of the upper and lower chamber liner portions 94 , 96 with their respect to faces 84 , 86 . The end 56 of the slit opening 52 is positioned short of the edge of the recess 54 in the liner assembly 50 so that once the inner slit passage door 60 is put into position the end of the door overlaps the end 56 of the slit 52 by a distance approximately equal to the overlap of the top and bottom edges as discussed above.
The progression of the assembly is shown in FIGS. 8 , 9 , 10 . The retracted door lift rods receive the inner slit passage door and retaining screws are inserted and tightened so that the door can then be actuated. A frontal view of the door with the lift rods 200 , 210 as shown in FIG. 11 as might be expected, the door being made of aluminum will tend to expand and contract with variations in temperature, as will doors made of any material that has a coefficient of thermal expansion that tends to create binding on lift member depending on the dimensional relationships established and the range of temperatures to be accommodated.
The requirement of positional accuracy and the freedom for thermal expansion is accommodated by making one door support rod, the left rod 200 here, a fixed rod such that the end of the rod 200 , for example, as shown in FIG. 12 is tightly clamped to the fixed hole configuration in the slit valve door. The machine screw 72 engaging the end of the rod tightly clamps the end of the rod 200 to the shoulders of the narrow pass through hole 63 in the inner slit passage door 60 . This tight clamping provides a good electrical path to ground from the door, so that the possibility of arcing is reduced or eliminated, and further sets a horizontal and vertical position of one end of the door. This clamping acts as an anchor (or pivot) around which the other floating end of the door and its support can move.
FIG. 13 shows the right-hand rod, floating rod 210 . Its rod receiving hole 68 is elongated in a sideways direction (e.g., FIG. 14 ) to allow for some expansion and contraction while the lower end of the rod is vertically fixed by a shoulder bolt 82 which clamps tightly against the bottom end of the floating rod 210 . The narrowness of the slot 68 prevents sideways (radial) motion. Note that there is a gap 74 between the end of the rod and the inwardly protruding flanges (shoulders) of the rod through hole 63 . The floating rod can thereby tilt, but is vertically fixed by the end flange (head) of the shoulder bolt 82 to allow free contraction and expansion of the slit passage door 60 as temperature variations take place about the fixed central axis of the fixed lift rod 200 . Since the temperature variation is only approximately 100 to 150 degrees from ambient and the distance between the two lift rod holes is approximately six inches, the expansion will be quite manageable with this configuration.
A configuration according to the invention as has been described above typically includes an outer (chamber sealing) slit valve assembly. The present invention provides an inner slit passage door to block the deposition of polymers and other byproducts of the process in the chamber from depositing on the wall of the processing chamber. In this configuration the inside of the outer slit valve door does not have to be cleaned during a normal cleaning of the processing chamber. Therefore, the seal between a transfer chamber of a cluster tool is not affected if one of the chambers needs to be cleaned, whereas in the past, chamber cleaning always meant that the cluster tool and its transfer chamber was disrupted. Another benefit of a configuration using an inner slit passage door as described herein is to improve the uniformity of the distance between the edge of the substrate being processed at the substrate processing location in the chamber and the surrounding liner which defines the limits of the plasma envelope over the substrate. In the conventional configuration there was a large hole in the chamber liner which allowed plasma to expand into it. The expansion of plasma created a distortion on the plasma flux over the substrate being processed and variations in substrate processing from the side closest to the substrate transfer passage to the opposite side were noted. In a configuration according to the invention, the discontinuity in the plasma flux due to the slit transfer passage has bee eliminated, by the substitution of a door at the same electrical potential as the liner, to create a nearly uniform distance between the edge of the substrate being processed and the liner lining the wall of the processing chamber adjacent to the substrate. The configuration accomplishes this without substantially increasing the risk that particles will be generated in the chamber either by the movement of a dry door, or by movement of a door whose exposed surfaces have been coated with process byproducts. The bellows assembly seal provides dry sealing, without introduction of particles, while the cleverly curved and/or beveled surfaces of the door and the liners surfaces that it faces reduce the risk of polymer flake off, and peel off during operation. The door can be easily removed and cleaned as a unit with the liner assembly thereby simplifying the maintenance steps need to achieve a clean chamber, to return the chamber to production as soon as possible.
While the invention has been described in regards to specific embodiments, those skilled in the art recognize that changes can be made in form and detail without departing from the spirit and scope of the invention.
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In a substrate vacuum processing chamber, a second inner slit passage door apparatus and method to supplement the normal slit valve and its door at the outside of the chamber. The inner slit passage door, blocks the slit passage at or adjacent the substrate processing location in a vacuum processing chamber to prevent process byproducts from depositing on the inner surfaces of the slit passage beyond the slit passage door and improves the uniformity of plasma in the processing chamber by eliminating a large cavity adjacent to the substrate processing location into which the plasma would otherwise expand. The inner slit passage door is configured and positioned in such a way as to avoid generating particles from the opening and closing motion of the second slit valve door, as it does not rub against any element of the chamber during its motion and the inner slit passage door is positioned with a predetermined gap from adjacent pieces and the door configuration includes beveled surfaces to further reduce the chance for particle generation, even when there is deposition of process byproducts on the door and its adjacent surfaces.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a slider link press. More precisely, the present invention relates to a slider link press having high operational precision and increased pressing force.
2. Description of the Related Art
Japanese Laid-Open Patent Publication No. 11-226788, presently owned by Applicant, is an example of a slider link press. The slider link press includes a crank shaft that rotates in a horizontal direction on a frame above a slide. An oscillating link is perpendicular to the crank shaft and faces a roughly horizontal direction. The oscillating link pivots in a reciprocating manner around an oscillation fulcrum shaft as a center. The oscillation fulcrum shaft is parallel to and at a separate position from a crank shaft. A slider joins rotatably with a crank pin on the crank shaft and is slidable in a linear groove provided in the longitudinal direction of the oscillating link.
A vertical connecting link, has two ends connected in a freely oscillating manner between a lower surface of the oscillating link and the upper surface of the slide. The rotation output of the crank shaft is converted to a reciprocating motion by the oscillating link and the slide operates.
In this related art, the crank shaft is aligned through the front of the slide press, and the oscillating link is perpendicular with this crank shaft. A hole for a crank shaft is perforated on a left-side plate and a right-side plate in the crown. This requirement greatly weakens the frame body and reduces rigidity during operation. This requirement further forces drive mechanisms (motor and fly wheel) to one side of the slide link press, resulting in instability and loss of balance. Compensation for these drawbacks requires a large and expensive frame to minimize vibration and maintain alignment. This cure fails to increase productivity.
Japanese Laid Open Utility Model Publication No. 63-56996, is an example of a rigid press machine requiring a tubular spacer inserted between each column in a front-back and left-right direction. A supporting tie rod passes through the spacer and the columns on either side and binds them together. As a result, the deformation in the columns under load is reduced, and working precision is improved.
However, while the interval between the columns can be maintained, the cross-sectional area of the spacer is small, and the deformation stress of the columns cannot be absorbed. Thus, when an eccentric load is applied on the slide, an edge of the slide contacts the slide guide in a linear manner and ‘slide galling’ frequently results and permanently damages the slide guide. When this type of linear contact ‘slide galling’ occurs, the slide does not operate smoothly and work precision and productivity greatly suffer.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention is to provide a rigid slider link press.
It is another object of the present invention to provide a press with a slide link where the slide decent time is slowed and the ascent time is speeded up.
It is another object of the present invention to provide a press where press torque is increased at bottom dead center.
It is another object of the present invention to provide a press where a center of gravity of a fly wheel is lowered and vibration is reduced.
It is another object of the present invention to provide a press that withstands and absorbs eccentric loads placed on a slide and operates smoothly without undue wear.
It is another object of the present invention to provide a press where a stay and spacer absorb and distribute deformation pressure and prevent frame damage.
It is another object of the present invention to provide a press with horizontal rigidity during press operations.
Briefly stated, the present invention relates to a slider link press which includes an oscillation link operating about a fulcrum shaft and an eccentric crank pin. A connecting link connects the oscillation link to a slide. The oscillating link and fulcrum shaft act to increase press torque and reduce downward press speed while increasing upward press speed. The eccentric crank pin operates the oscillation link, aids in torque increase, and provides reciprocating movement to the slide. A slide includes pivotable slide gibs that engage reciprocal fixed gibs to maintain parallel surface contact and absorb and eliminate eccentric loads on the slide and press. Stays and spacers align sides of the press and eliminates flexing under load while absorbing and distributing eccentric deformation pressure.
According to an embodiment of the present invention, there is provided a slider link press device, comprising: a crank shaft and a fulcrum shaft, first means for linking the crank shaft to the fulcrum shaft, the first means being operable in a first arc about the fulcrum shaft, a crank pin on the crank shaft, the crank pin providing an eccentric displacement to the first means, a slide having a top and a bottom dead center position, second means for linking of the first means to the slide, the first means being effective to receive the eccentric displacement and to operate in the first arc to drive the slide in a cycle, the first means perpendicular to the crank shaft and the fulcrum shaft, the first means permitting an increase in a force applied to the slide at the bottom dead center position and permitting an increase in a slide descent time whereby a precision increases and a slide assent time decreases, guiding means for guiding the slide in a cycle, and the guiding means permitting elimination of eccentric loads upon the slide while the slide operates in the cycle whereby the precision increases.
According to another embodiment of the present invention there is a slider link press device, wherein: the fulcrum shaft includes a fulcrum shaft center, the first link means is horizontal to the fulcrum shaft center at the bottom dead center position, the eccentric displacement is a trajectory circle, an angular velocity of the crank shaft is constant, a first position (O) is a rotation center of the crank shaft, a first tangent point (PT) is defined on the trajectory circle at the top dead center position respective to the fulcrum shaft center, a second tangent point (PR) is defined on the trajectory circle at the bottom dead center position horizontal to the fulcrum shaft center, a first angle (θ 1 ) is a first link means oscillation angle between the first tangent point (PT), the fulcrum shaft center, and the second tangent point (PR), a second angle (θ 2 ) is defined between the first tangent point (PT), the first position (O), and the second tangent point (PR), the first angle (θ 1 ) and the second angle (θ 2 ) have the following relationship, and
(θ 2 )minimum=180 degrees−(θ 1 ) (I)
(θ 2 )maximum=180 degrees+(θ 1 ) (II)
the second link means descends under formula (II) whereby the a torque at the bottom dead center is increased and decent time is increased.
According to another embodiment of the present invention there is provided a slider link press device, wherein: a distance L 1 is defined between a maximum eccentricity of said crank pin 11 and said fulcrum shaft center, a distance L 2 is defined between the center of said first link means and said fulcrum shaft center, a center of said first link means is a center axis of said slide, a first torque applied to said crank pin is F 1 , a second torque applied to said slide is F 2 , said first torque is at a minimum where F 1 =F 2 and said slide is at said top and bottom dead center positions, said slider link press effective to increase during an operating cycle of said slide as said crank pin travels from the top dead center to the bottom dead center, and said second torque is at a maximum at a maximum eccentricity of said crank pin and where F 2 =F 1 ×L 1 /L 2 and said first means is effective to increase said second torque.
According to another embodiment of the present invention there is a slider link press device, further comprising: a drive assembly, the drive assembly effective to drive the crank shaft, a speed reducing module and a fly wheel in the drive assembly, a frame assembly supporting the drive assembly and the slide, and the crank shaft above the slide.
According to another embodiment of the present invention there is a slider link press device, wherein: the frame assembly includes a crown assembly, the crown assembly above the slide, the first link means, the crank shaft, and the fulcrum shaft in the crown assembly, and the fly wheel having a center of gravity below the crown, whereby stability is increased and operating vibration is reduced.
According to another embodiment of the present invention there is a slider link press device, wherein: the slide includes a vertical slide center, the slide center being a press center, and the rotation center vertically aligned with the press center.
According to another embodiment of the present invention there is a slider link press device, further comprising: at least first and second columns in the frame, the first and second columns below the crown, at least first and second stays, the first and second stays between the first and second columns at the bottom dead center position, and the first and second stays operably joining the first and second columns whereby the columns are maintained parallel and the frame is rigid and resists high operating pressure and eccentric slide pressure.
According to another embodiment of the present invention there is a slider link press device, further comprising: a plurality of vertical corner surfaces on the slide, a plurality of fixed gibs on the guiding means, the fixed gibs along inner surfaces of the first and second columns, the fixed gibs opposite the slide, the fixed gibs aligned adjacent to the corner surfaces, the corner surfaces being slidably aligned with the fixed gibs, a plurality of slide gibs on the guiding means, the plurality of slide gibs on the corner surfaces, the slide gibs having an engagement surface parallel to the fixed gibs, and means for pivoting the slide gibs relative to the fixed gibs, and the pivoting means effective to maintain the engagement surfaces parallel to the fixed gibs whereby the fixed gibs slidably guide the slide and eliminate eccentric forces on the slide.
According to another embodiment of the present invention there is a slider link press device, further comprising: a plurality of holes in the pivot means, the slide gibs in each the hole, the slide gibs pivotable in each the hole, the holes at a top and bottom side of each the corner surface, the first and second stays are equidistant the slide gibs when the slide is at the bottom dead center position, and the stays, the slide gibs, and the pivot means absorb eccentric forces whereby the first and second columns are maintained in parallel and the slide operates parallel to the fixed gibs.
According to another embodiment of the present invention there is a slider link press device, further comprising: at least one spacer, the spacer between each the stay and each respective the first and second column, the spacer selectable to maintain the first and second columns in parallel, and the spacer being effective as a slip plane whereby the spacer minimizes damage to the first and second columns during tightening the stays.
According to another embodiment of the present invention there is provided a slider link press, having a slide operated by converting a rotational crank shaft output converted to a reciprocating motion by an oscillating link, comprising: an oscillation fulcrum shaft, the oscillation fulcrum shaft parallel to the crank shaft, the oscillating link effective to operably join the oscillation fulcrum shaft and the crank shaft, the oscillating link receiving the output as an eccentric displacement, the oscillating link operation in an arc about the oscillation fulcrum shaft, crank pin on the crank shaft, the crank pin effective to transfer the eccentric displacement to the oscillating link, and the oscillating link effective to transfer the reciprocating motion to the slide and act as a force multiplier whereby the slide operates with increased pressing force, has a lower descent time and a faster ascent time.
According to another embodiment of the present invention there is provided a slider link press, further comprising: a speed reduction module, a fly wheel, the speed reduction module and the fly wheel effective as drive modules for the crank shaft, a frame, the frame including the drive modules and the slide, the fly wheel and the speed reduction modules effective to provide the eccentric displacement to the crank pin whereby the slide operates in a cycle.
According to an embodiment of the present invention there is provided a slider link press device in which a frame includes first and second columns, and a slide operates between the columns, comprising: first and second stays, the first and second stays between the first and second columns, the first and second stays effective to rigidly join the first and second columns, and the first and second stays effect to resist an eccentric force of the crank shaft whereby the first and second columns are maintained in parallel.
According to another embodiment of the present invention there is provided a slider link press device, further comprising: at least one spacer, the spacer between each the first and second column and each respective the first and second stay, and the spacer having a thickness effective to maintain the first and second columns in parallel.
The above, and other objects, features, and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a front view of the principal parts of a slide press.
FIG. 2 is a longitudinal side view of FIG. 1 .
FIG. 3 is a partial rear view of FIG. 1 .
FIG. 4 is a view of an oscillating link with a slide at a bottom dead center position.
FIG. 5 is a view of an oscillating link with a slide at a top dead center position.
FIG. 6 is a motion model diagram of the oscillating link.
FIG. 7 is a comparative diagram of motion waveforms for the press.
FIG. 8 is a comparative diagram of motion waveforms of torque curves for the press.
FIG. 9 is a working torque distribution diagram for the press.
FIG. 10 is a front view of an embodiment of the press.
FIG. 11 is a longitudinal side view of FIG. 10 .
FIG. 12 is a cross-section from the view along the line A—A in FIG. 10 .
FIG. 13 is a front view of FIG. 12 .
FIG. 14 is a partial perspective view FIG. 13 .
FIG. 15 is a partial view of a stay of FIG. 14 .
FIG. 16 is a perspective view of a slide.
FIG. 17 is a perspective view of a slide gib as seen in FIG. 16 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, an embodiment of a slider link press 50 includes a first column 1 and a second column 2 . Columns 1 , 2 form a left and right side wall of slider link press 50 . A rib 3 joins a bottom portion of columns 1 , 2 . A pair of stays 4 , 5 join an upper portion of columns 1 , 2 . Rib 3 and stays 4 , 5 act to maintain equal spacing between columns 1 , 2 , as will be explained.
A slide 6 operates between stays 4 , 5 above rib 3 . A bolster 21 is on rib 3 opposite slide 6 . A crown 7 fixes and joins upper parts of columns 1 , 2 . A front and back rib 9 are included in crown 7 . A crank shaft 8 extends horizontally to crown 7 . Crank shaft 8 is rotatably supported as it passes through the walls of front and back rib 9 .
An oscillation fulcrum shaft 10 is on a right side of crown 7 . Oscillation fulcrum shaft 10 is generally parallel with crank shaft 8 , as will be explained.
An oscillating link 12 is pivotably retained on one side by oscillation fulcrum shaft 10 . A crank pin 11 slidably joins oscillating link 12 to crank shaft 8 , as will be explained. Oscillating link 12 operates in a reciprocating arc-type motion about oscillation fulcrum shaft 10 , as will be explained.
A crank pin insertion window 13 extends in a longitudinal direction in oscillating link 12 . Crank pin 11 is operably retained in insertion window 13 by a pair of sliders 14 , 15 . Crank pin 11 therefore slides forward and backward during operation relative to oscillating link 12 . Crank pin 11 is eccentric to crank shaft 8 .
Insertion window 13 of oscillating link 12 includes a base module 12 A and an opposing lid module 12 B. During assembly, crank pin 11 is retained in oscillating link 12 and insertion window 13 by a lid body 12 C. Lid body 12 C is attached to respective base module 12 A and lid module 12 B by bolts or screws. It is to be understood, that lid body 12 C may be affixed to oscillating link 12 by any manner effective to operably retain crank pin 11 .
Spherical bearings 16 are on both an upper surface of slide 6 and an opposing lower surface of oscillating link 12 . Spherical bearings 16 are generally vertically opposite each other. A connecting link 17 is retained between spherical bearings 16 . Connecting link 17 has spherical ends that rotatably mate with respective spherical bearings 16 . Connecting link 17 and spherical bearings 16 mechanically and operably link slide 6 to oscillating link 12 .
A multistage speed reduction gear assembly 18 connects to a back end of crank shaft 8 . A motor 20 and a fly wheel 19 provide multistage speed reduction gear assembly 18 with drive force. The drive force from multistage speed reduction gear assembly 18 drives a back end of crank shaft 8 .
It should be understood that an upper and lower die (both not shown) are affixed respectively to a lower surface of slide 6 and to an upper surface of bolster 21 . The dies are used in the pressing of a product.
Additionally referring now to FIG. 3, a main gear 18 A, of multistage speed reduction gear assembly 18 is in a middle section between a left and a right side column portions 1 A, 2 A. A middle gear 18 B and a fly wheel 19 are also positioned in the middle section and provide drive force to multistage speed reduction gear assembly 18 .
It should be noted that the center shaft of fly wheel 19 is positioned below crown 7 . The center of gravity of fly wheel 19 is therefore below crown 7 and provides an important stability to slider link press 50 , reduces vibration, and improves safety.
It should be additionally noted that main gear 18 A, middle gear 18 B, and fly wheel 19 are generally positioned along a vertical centerline between columns 1 , 2 thereby further centering the center of gravity of speed reduction gear assembly 18 . This positioning further reduces operational vibration.
Additionally referring now to FIG. 4 where oscillating link 12 and slide 6 are at a bottom dead center position. In the bottom dead center position, the position of crank pin 11 is aligned with a horizontally extended center line (PR) (not shown) from fulcrum shaft 10 .
Additionally referring now to FIG. 5, where oscillating link 12 and slide 6 are at a top dead center position. In the top dead center position oscillating link 12 and slide 6 are at a maximum distance in an operational cycle.
Additionally referring now to FIG. 6, where the operational position of crank pin 11 is shown as tangent points on a trajectory circle of crank pin 11 . The trajectory circle is determined by the eccentric amount of crank 8 and fulcrum shaft 10 .
At top dead center, the position of crank pin 11 is at a tangent point (PT) on a line that joins the trajectory circle of crank pin 11 with fulcrum shaft 10 .
At bottom dead center, a position (PR) of crank pin 11 is on a horizontally extending center line of fulcrum shaft 10 of oscillation link 12 and is at a tangent point to the trajectory circle of crank pin 11 .
An angle theta L (θL) is a link oscillation angle is defined between tangent point (PT), the center of oscillation fulcrum shaft 10 , and horizontal extending center line (PR).
A position (O) is a rotation center of crank shaft 8 .
An angle PR-O-PT, connecting tangent points PT and PR is:
At a minimum at, angle PR - O - PT= 180 degrees−theta L (θL) (III)
At a maximum at, angle PR - O - PT= 180 degrees+theta L (θL) (VI)
During operation, the angular velocity of crank shaft 8 is constant. By setting the rotation direction of crank shaft 8 so that connecting link 17 is descending when in the above situation (VI), slide 6 of slider link press 50 has a longer descent time and a shorter ascent time and torque is increased.
During operation, the rotation of crank shaft 8 drives crank pin 11 , and oscillating link 12 oscillates in an up-and-down arc motion. Oscillating link 12 is connected with oscillation fulcrum shaft 10 as a rotation center. Connecting link 17 , operably joined to oscillating link 12 has a corresponding general up-and-down motion.
Referring additionally now to FIG. 7, a motion comparison is made between a general crank press (solid line with box) and the present embodiment slider link press 50 (solid line with diamond).
The present embodiment of slider link press 50 is shown through one operation cycle as having a longer and slower descending stroke and a shorter and quicker ascending stroke. It is to be understood, that such modification of the stroke time is beneficial to accuracy and precision. As shown, the general crank press has a low point at 180 degrees of rotation and the present embodiment has a low point beyond 180 degrees. The degree of difference is the time difference. It is to be understood that the total slide 6 cycle time remains the same and that the rate of travel of slide 6 changes during the cycle.
It should be additionally understood that the horizontal center of crank shaft 8 and a vertical press center (not shown) of slide 6 are aligned on the same vertical axis, further beneficially influencing the cycle time, stroke length, and press torque.
Additionally referring now to FIG. 8, a torque comparison indicates that the allowable load in the present embodiment is greater than that of a general crank press. This additional load is excellent for precision cold forging and is an important, but not only, result of the present invention.
It is to be understood, that positioning the elements of the present construction improves both balance and rigidity, reduces the size of slider link press 50 , and improves operational efficiency. Specifically, connecting link 17 is directly above slide 6 and perpendicular to crank shaft 8 while oscillation fulcrum shaft 10 is parallel to crank shaft 8 , thereby increasing left-right symmetry in the device and reducing overall size.
It is to be further understood, that by positioning the components as listed above and shown in the drawings, frame holes are minimized in slider link press 50 and rigidity and compactness are again improved and vibration restricted.
It is to be further understood that since speed reduction gear assembly 18 and fly wheel 19 , are positioned between ribs 9 in the back part of crown 7 , the size of slider link press 50 is reduced, balance is improved, vibration reduces, and a higher productivity results.
It should be further understood, that positioning the center of gravity of fly wheel 19 below the position of crown 7 , vibration is further reduced and stability increased.
Referring additionally now to FIG. 9, where the center axis of press 50 (slide 6 ) and crank shaft 8 are aligned to the same vertical axis. As described above, the center of crank shaft 8 is defined as O (previously shown). A distance L 1 is defined between a maximum eccentricity of crank pin 11 and a center of oscillation fulcrum shaft 10 . A distance L 2 is defined between the center axis of connecting link 17 , and the center of oscillation fulcrum shaft 10 .
The center of connecting link 17 is to be understood as the center axis of slide 6 .
The pressure (torque) applied to crank pin 11 is defined as F 1 . The pressure applied to slide 6 is defined as F 2 . It is to be understood, that the pressure applied on crank pin 11 is at a minimum value where F 1 =F 2 at slide 6 top dead center and bottom dead center positions.
It is to be further understood, that the pressure (torque) increases during an operating cycle of slider link press 50 , as crank pin 11 travels from the top dead center to the bottom dead center. The combined pressure (torque) at the maximum eccentricity of crank pin 11 , is defined by the formula F 2 =F 1 ×L 1 /L 2 .
It should be understood, that oscillation link 12 operates as a lever and boots pressure (torque) and power with respect to operating slide crank press 50 . Where L 1 , maximum eccentricity, increases, pressure (torque) also increases.
Additionally referring now to FIGS. 10 and 11, bolster 21 is below slide 6 . Two sets of fixed gibs 25 are vertically mounted on columns 1 , 2 . Fixed gibs 25 are mounted opposite each vertical corner of slide 6 . Two sets of slide gibs 24 are vertically mounted on each corner of slide 6 . Slide gibs 24 engage and slide on corresponding fixed gibs 25 , as will be explained. Slide gibs 24 have a partially circular construction, as will be explained.
Additionally referring now to FIG. 12, fixed gibs 25 have the shape of a vertical rectangle. Each outside vertical corner of slide 6 is formed in the shape of an ‘L’ corresponding to the shape of fixed gibs 25 .
Stays 4 , 5 are between columns 1 , 2 adjacent an outer surface of fixed gibs 25 . Stays 4 , 5 provide extensive support and vibratory damping to slider link press 50 , as will be explained. A spacer 22 inserted on one surface between stays 4 , 5 and respective columns 1 , 2 and maintains a required spacing. A required spacing between columns 1 , 2 is maintained by adjusting a thickness of spacer 22 while retaining rigidity. Spacer 22 also acts to absorb and distribute deformation pressure on columns 1 , 2 during adjustment of stays 4 , 5 .
Additionally referring now to FIGS. 13 and 14, bolts 30 affix stays 4 , 5 to respective columns 1 , 2 . Bolts 30 are inserted from an inside surface of stays 4 , 5 , through spacers 22 and into respective columns 1 , 2 and tightened to ensure horizontal rigidity and resistance to eccentric loads on slide 6 . It should be understood that additional methods of rigidly affixing stays 4 , 5 to columns 1 , 2 are available but must minimize vibration, increase rigidity, minimize deformation and serve similar functions to bolts 30 .
Additionally referring now to FIG. 15, each stay 4 , 5 includes a front thick board 42 , a back thick board 43 , and a side board 44 . An open window 41 is formed through the center of boards 42 , 43 . During assembly, side board 44 is tightened to respective columns 1 , 2 by bolts 30 from an interior side. Spacer 22 additionally aids in preventing damage, and absorbing and distributing deformation pressure to columns 1 , 2 during tightening of bolts 30 . To increase horizontal and transverse rigidity, stays 4 , 5 may be alternatively formed as a single unit or with additional supporting members.
Additionally referring now to FIGS. 16 and 17, a corner surface 23 is on each vertical corner of slide 6 . Corner surfaces 23 are formed corresponding to fixed gibs 25 , described above. Corner surfaces 23 have an L-shaped cross-section, but may be adapted to other shapes referenced to fixed gibs 25 . Holes 27 are at a top and bottom position of each corner surface 23 , opposite fixed gibs 25 .
Sliding gibs 24 are in respective holes 27 opposite fixed gibs 25 . Sliding gibs 24 have a circular cross-section corresponding to holes 27 and a two-plane-L-shaped face corresponding to corner surfaces 23 . The L-shaped faces of sliding gibs 24 match the outside corner surfaces of fixed gibs 25 . Sliding gibs 24 rotate within holes 27 to accommodate any torsion placed upon slide 6 during operation, as will be explained.
It is to be understood, that when slide 6 is at the bottom dead center position, stays 4 , 5 are positioned, equidistant, between top and bottom slide gibs 24 . As a result, stays 4 , 5 are positioned to counter the affects of maximum pressure (torsion) during operation. As indicated above, it is to be understood that maximum pressure (torsion) is at the bottom dead center position.
During normal operations, slide 6 , through connecting link 17 and oscillating link 12 work to maintain alignment between corner surfaces 23 of slide 6 and fixed gibs 25 . Precise balance is difficult to maintain during the complete operation cycle and slide 6 may operate in an non-uniformly parallel manner (i.e. the result of an eccentric load) for a period of time.
Where an eccentric load operates to shift slide 6 , the L-shaped face of slide gibs 24 contacts the corresponding surface of fixed gibs 25 , and holes 27 allow slide gibs 24 to rotate, maintain parallel contact, accommodate any eccentric load. This operation ensures smooth press operation and extends life. Where an eccentric load is larger than expected, the above invention also accommodates additional load through the use and correct positioning of strays 4 , 5 on columns 1 , 2 . As a result, the phenomenon of “linear contact” and “slide galling” found in the related art is eliminated and seizure of the guide surfaces and slide 6 is eliminated.
Further, it is to be understood, that the use of spacers 22 prevents damage to columns 1 , 2 , by both acting as slip planes to eliminate over-tightening damage, and by acting to ensure spacing alignment with slide 6 to resist eccentric force.
Since slide gibs 24 have an L-shaped face, there are two surfaces that match the two corresponding surfaces of each fixed gib 25 and, through contact, and rotation maintain alignment of slide 6 . Since slide gibs 24 pivot in the direction of surface contact, the L-shaped face is maintained in parallel, surface contact alignment with the surfaces of fixed gibs 25 .
In combination, columns 1 , 2 , stays 4 , 5 , ribs 3 , 9 , and the other elements of slider link press 50 easily provide horizontal rigidity to ensure a maximum available pressure (torque) with a low maintenance that is not found in the related art.
Although only a single or few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiment(s) without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, means-plus function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus although a nail and screw may not be structural equivalents in that a nail relies entirely on friction between a wooden part and a cylindrical surface whereas a screw's helical surface positively engages the wooden part, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures.
Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.
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A slider link press includes an oscillation link operating about a fulcrum shaft and an eccentric crank pin. A connecting link connects the oscillation link to a slide. The oscillating link and fulcrum shaft act to increase press torque, reduce downward press speed, and increases upward press speed thereby maintaining cycle time. The eccentric crank pin operates the oscillation link, aids in torque increase, and provides reciprocating movement to the slide. The slide includes pivotable slide gibs that engage reciprocal fixed gibs to maintain parallel surface contact and absorb and eliminate eccentric loads on the slide and the press. Stays and spacers align sides of the press and eliminate flexing under load while absorbing and distributing deformation pressure.
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This is a continuation of application Ser. No. 776,043, filed Mar. 9, 1977, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a method for recovering an oil residue from an oil-containing clay and treating the oil-containing clay without causing the environmental contamination.
In the decoloration of an animal and vegetable oil and fat using clay or mixtures of clay and active carbon as a decoloring agent, coloring matters present in the oil and fat are removed by adsorption. At this time, 10-50% of the oil and fat based on the weight of the decoloring agent are adsorbed or attached and therefore, the clay containing the oil and fat as well as the coloring matters is obtained.
The term of an "oil-containing clay" used hereinafter means a mixture consisting mainly of clay containing an animal and vegetable oil and fat, which is by-produced in the decoloration step of the oil and fat.
Because the oil-containing clay can not be disposed or discarded as it is, there has, hitherto, been effected a treatment method including steps of adding a small amount of alkali and water into the oil-containing clay, boiling it for 2-3 hours, allowing same to stand for 6-24 hours, separating and recovering the resulting oil portion and thereafter, discarding clay sludges or utilizing them for land filling.
With this conventional method, however, the recovery percentage of oil is low so that about 10% of oil are still maintained in the clay sludge after the recovery of oil. Therefore there are disadvantages that the environmental contamination is caused by discarding the clay sludge, the treatment efficiency is lowered due to the prolonged time for separating the oil portion, and the waste water discharged after the recovery of oil contaminates water because it has a high COD of 15,000-30,000 ppm and a high oil content of more than 1,000 ppm.
SUMMARY OF THE INVENTION
An object of this invention is therefore to provide a treatment method for the oil-containing clay, in which the oil portion is recovered with high yield in a shortened treatment time and clay sludges and waste water discharged after the recovery of oil cause no environmental contamination.
In accordance with this invention, there is provided a treatment method for the oil-containing clay which comprises adding to the oil-containing clay water and an alkali in an amount corresponding to at least saponification value relative to the oil content to obtain a slurry, and if desired, subjecting the resulting slurry to a pretreatment at temperatures of about 90°-95° C., then treating the slurry at temperatures of about 110° C. or more under high pressure to strip the oil portion, adding to same an acid in an amount sufficient for neutralization, and separating and recovering the floating oil and fat.
DETAILED DESCRIPTION OF THE INVENTION
We have now found that when the oil-containing clay is treated with an alkali under high temperature and high pressure, the recovery of oil from the oil-containing clay can be effected with good yield.
An alkali which may be used is a caustic alkali and preferably, caustic soda. The amount of alkali added should be in an amount corresponding to at least saponification value relative to the oil content. Since the oil-containing clay is normally acidic, it is preferred that amounts of 1.5 to 2 times the saponification value are used in practice.
The preferred amount of water added is in 2 to 5 times the amount of the oil-containing clay.
Alternatively, the alkali may be used in the form of an aqueous solution which has previously been dissolved in an amount of water to be added.
The oil-containing clay made a slurry by addition of water and alkali is then treated under high temperature and high pressure.
According to the preferred embodiment of this invention, the slurry may conveniently be subject to a pretreatment at temperatures of about 90° to 95° C. prior to the treatment at high temperature and high pressure. The treatment period of time is more than 30 minutes, preferably 1 to 1.5 hours. By this pretreatment, the slurry is placed in such a condition that the oil portion is apt to be stripped from the clay and therefore, the subsequent procedures can be conveniently effected.
Next, the treatment at high temperature and high pressure may be conducted at temperatures of about 110° C. or more, preferably 140°-150° C. under pressures of more than about 5 kg/cm 2 , preferably 6 to 7 kg/cm 2 . Although the upper limit of temperature is not particularly critical, preferably it is 200° C. When exceeding 200° C., the oil portion of inferior quality is recovered.
For the purpose of the above treatment, apparatus such as an autoclave and a tubing may be used. The tubing is, for example, a metal pipe of 5-40 cm in inner diameter and 5-40 m in length. The oil-containing clay slurry is forced into the tubing with a high pressure steam by means of a plunger pump, and the stripping of oil is effected continuously while the slurry passes through the tubing. The use of tubing is preferred from the view-points that a continuous operation is possible with a high treatment efficiency, the cost of equipments is reduced, and the operation and the maintenance of security are easy.
By using such means, the treatment can be accomplished in a very short time and the stripping of oil is complete usually in periods of from 20 minutes to 2 hours.
Next, an acid is added and then, an oil portion is separated and floated. The acid which may be used is an inorganic acid and preferably, sulfuric acid. The floated oil phase usually contains a large quantity of fatty acids and after washing, can be used as fatty acid materials. The yield of recovery of oil is very high, i.e. more than 95%.
Then, the aqueous lower phase is separated into clay sludges and waste water by separating means such as a filter press. The clay sludge which includes an oil residue of less than 0.5% and water of about 50% incurs no danger of environmental contamination, so that it can be discarded as industrial wastes. Also, the waste water has a COD value of less than 3,000 ppm, an oil residue of less than 100 ppm and pH of 6-7. Since these values are remarkably low as compared with those obtained by the conventional methods, a load of post-treatment is reduced.
This waste water, after subjecting to the usual water treatment such as an activated sludge process, may be discharged, or without subjecting to such a water treatment may be reused for recycling as a part of water which is used in the first step of preparing a slurry from an oil-containing clay. Thus the recycling has advantages that the consumption of water can be saved and a load of the waste water treatment or a COD load can be reduced.
As mentioned above, this invention is very useful for industries in that the oil portion of an oil-containing clay can be nearly all separated and recovered in a short time and that clay sludges and waste water after the separation of oil can be placed in the condition of causing no trouble from the standpoint of the prevention of environmental contamination.
This invention will be illustrated by the following non-limitative example.
EXAMPLE
To 500 kg of an oil-containing clay (oil content, 25%) by-produced in the decoloration step of soybean oil were 1,500 kg of water and 27.3 kg of sodium hydroxide (corresponding to 150% of the saponification value) added to form a slurry.
The resulting slurry was charged into a pretreatment container and stirred at temperatures of 90°-95° C. for 30 minutes. After the pretreatment, the slurry was forced with a high pressure steam into a tubing (inner diameter 20 cm, length 18 m) consisting of a metal pipe by means of a plunger pump and thus, the oil portion was stripped. At this time the conditions were about 150° C. in temperature, about 5 kg/cm 2 in pressure of steam and about 25 kg/min. in a flow rate of the slurry. The treatment was continued for about 80 minutes.
The saponified product discharged from the tubing was introduced into a decomposition tank, where 18.4 kg of concentrated sulfuric acid (corresponding to the neutralization equivalent) were added at temperatures of 85°-95° C. and then, fatty acid was separated and floated. At this time the contents of the tank were adjusted to pH of 6.8-7.2 till the completion of decomposition.
The floated oil phase was charged through an overflow into a recovery tank, where water was removed. The oil thus obtained gave a yield of 120 kg (recovery ratio, 96%), and could be used for fatty acid materials.
The aqueous lower phase was filtered by a filter press to separate clay sludges from waste water. The clay sludge was obtained in the form of cake containing an oil residue of less than 1% and water of about 50%, and could be discarded as industrial wastes.
On the other hand, the waste water had a COD value of about 1,000 ppm, an oil residue of less than 50 ppm and pH of 6.5, and therefore a load of water treatment was remarkably reduced.
COMPARATIVE EXAMPLE
To 500 kg of the same oil-containing clay as in Example were 1,500 kg of water and 5 kg of sodium hydroxide (corresponding to 27% of the saponification equivalent) added to form a slurry.
The resulting slurry was charged into a boiling tank, boiled at 90°-95° C. for 3 hours and allowed to stand for 24 hours.
The floated oil was very low in yield, i.e. 60 kg (recovery ratio, 48%).
The aqueous lower phase was filtered by a filter press to separate a clay cake from waste water. The clay cake contained as much oil residue as about 10% and therefore, could not be discarded as it was. Also, the waste water has a COD of 30,000 ppm and an oil content of 1,000 ppm so that it would contaminate water when discharged.
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In the decoloration of an animal and vegetable fat and oil with clay, an oil-containing clay is obtained as by-products. Good recovery of oil is attained by subjecting the oil-containing clay to an alkali treatment under high temperature and high pressure, adding an acid in an amount necessary for neutralization and removing the floating oil. Clay sludges and waste water after the recovery of oil can be easily disposed without causing the environmental contamination.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part to U.S. application Ser. No. 498,347, filed May 26, 1983, now U.S. Pat. No. 4,608,742.
BACKGROUND OF THE INVENTION
This invention relates to forging and more specifically to methods for making a component part of two dissimilar non-weldable materials. In particular, the invention relates to a forging process for producing a bi-metal mechanical joint between a forged titanium member and a member made of a dissimilar metal.
In aircraft and aerospace and industries composite parts made from dissimilar metals are often used. A typical example is a titanium turbine wheel disc mounted on a hardened steel shaft. Currently the titanium disc is bolted to the steel shaft. The hole in the cener of the titanium disc reduces its structual integrity and therefore, the thickness of the disc has to be increased to maintain the operating stresses at an acceptable level. The current state of the art for welding dissimilar metals, such as titanium and steel, results in a brittle joint which is seldom structurally useful and is incapable of carrying a reasonable load.
The known prior art teaches either using a relatively soft cold workable material and a relatively hard material for making mechanical joints between two dissimilar materials, or when both parts to be joined are of a hard material, heating the part to be deformed. In the latter case, the mating portions of the two parts to be joined need to be machined to close tolerances, so that a minimum of deformation of the heated part is required.
It is, therefore, an object of the present invention to provide a joint between two dissimilar metal parts in which one of the parts is forged during the formation of the joint. The deformed part must remain mechanically secure within the non-deformed part in such a way as to avoid looseness or fretting between the joined parts. Since the non-deformed part remains with the formed part when the joint is made, it is important that the interface of the two parts include materials which retard or prevent dissimilar metals corrosion and do not otherwise create problems during the lifetime of the part. On the other hand, it is important that steps be taken to avoid oxidation, which would occur during the forging operation with the titanium and with any other active metals forming the joint. It is also to provide a joint between titanium and dissimilar metals in which the size of the joint is reduced over that of the prior art and requirements for further fastening techniques in the joint are reduced.
SUMMARY OF THE INVENTION
This invention relates to a method for making a mechanical joint between two dissimilar metals having similar hardness properties, in which the joint is accomplished during the forging of one of the parts. In particular, the invention relates to the combination of titanium with a diverse metal, such as steel or aluminum, in which the diverse metal has formed thereon its portion of the joint. The diverse metal is positioned in a forging die used to forge the titanium to a forged shape. When the forging operation is completed, the titanium conforms to the shape of the diverse metal, including the shape of the diverse metal's portion of the joint. In order that the diverse metal retains a relative dimension at the joint which conforms to the operating dimensions of the titanium, the diverse metal is heated to a temperature sufficient to compensate for expansion at elevated temperatures and yet low enough to avoid substantial deformation by the diverse metal during the forging operation.
In order to prevent oxidation of the titanium and of the diverse metal at the interface between the two parts, a boron nitride lubricant is applied to the titanium. Prior to forging, the coated titanium is heated in a non-oxidizing atmosphere, thereby causing the boron nitride to change its crystalline structure. This recrystallization prevents the boron nitride from oxidizing. The boron nitride inhibits oxidation of the titanium during forging and does not form an abrasive surface between the parts. Dissimilar metal corrosion may be further prevented by plating one of the parts at the joint prior to forging.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an axial sectional view of a bimetallic turbine wheel formed in accordance with the invention illustrated prior to being completed by machining operations subsequent to being forged (left), and as completed (right);
FIG. 2 shows the placement of a billet on a lower forging die prior to forging the turbine wheel of FIG. 1; and
FIG. 3 shows a bi-metallic transition ring formed in accordance with the invention used for coupling a power transmission shaft to a flexure diaphragm.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a bi-metallic turbine wheel 11 formed in accordance with the invention is shown in cross section along its center axis A--A. To the left of the axis A--A, the turbine wheel 11 is shown as machined, with the outlines of the original forging being shown in phantom. To the right of the center axis A--A, the turbine wheel 11 is shown as originally forged, prior to final machining operations. The turbine wheel 11 consists of a titanium disc 13 and a shaft 14. The shaft is preferrably made of steel, but may be of an alloy of any Group 8 metal. The disc 13 and shaft 14 are in intimate contact at an interface 16. The interface 16 is appropriately curved so as to prevent axial separation of the disc 13 from the shaft 14. In order to lock the disc 13 into rotational alignment with the shaft 14, a plurality of keyways 18 are bored about an inner circumference of the shaft 14 at the interface 16, with the disc 13 conforming to the keyways 18 at the interface 16. With this arrangement, the disc 13 is secured to the shaft 14 without the benefit of fasteners or bonding techniques.
As can be seen, final machining of exterior parts of the turbine wheel 11 is accomplished after forging. Thus, the external shape of both the disc 13 and the shaft 14 are established after the forging operation. The shape of the interface 16 is established during forging on the disc 13 and is accomplished by machining operations on the shaft 14 prior to forging the turbine wheel 11.
For the purposes of this description, "forging" of the turbine wheel is intended to refer to a forging operation in which the disc 13 is forged onto the shaft 14. While it is likely that in many cases, the shaft 14 will also be formed by forging, this operation occurs prior to machining and forms no part of the invention. For this reason, the description of the forging operation will refer only to the procedure for forging the disc 13 onto the shaft 14.
FIG. 2 shows the shaft 14 in place in a lower forging die form 20. The shaft 14 has been placed in a receiving cavity 21 in the lower die form 20, with the interface 16 exposed. A titanium billet 23 is placed on the lower die form 20 over the shaft 14 so that the billet 23 can be forged into the disc 13. The shaft 14 has been prepared by completely machining the shaft 14 at the interface 16, including drilling the keyways 18 prior to shaping the interface 16 and smoothing the keyways 18. A vent hole 25 has been provided in the shaft 14 and communicates with a corresponding vent hole 26 in the lower die form 20. As will be seen later, the vent holes 25, 26 allow the billet 23 to be forged into an inside cavity portion 27 of the shaft 14 at the interface 16.
In order to forge the titanium disc 13 onto the steel shaft 14, the materials must be heated to appropriate temperatures so that the titanium billet 23 deforms, without substantially deforming the steel shaft 14. The ability of the steel shaft 14 to retain its shape is of particular importance at the interface 16 because the shape of the interface 16 is important in retaining the disc 13 on the shaft 14 when the turbine wheel 11 is placed in service.
In order to forge the disc 13 and shaft 14 together, the titanium billet 23 is provided in a plastic state and is placed on the lower die 20 in the manner stated. The billet 23 is heated to a temperature of plasticity in order that the titanium billet material is sufficiently malleable to be forged by the die (not completely shown) to thereby become the disc 13. Since the steel shaft 14 is approximately in its final shape at the time of forging, the shaft 14 must be at a temperature below its temperature of plasticity in order that it not be significantly deformed during forging operations. In the preferred embodiment, the billet 23 is heated prior to forging to a temperature of approximately 1100° C. (2000° F.). The forging temperature is, of course, greater than the operating temperature of the turbine wheel 11. This results in the turbine wheel 11 operating with the turbine disc 13 being contracted from its size at the time of forging. Since the size of the turbine disc 13 is critical at the interface 16, a contraction in size may have a tendency of loosening the disc 13 from the shaft 14. Some of this loosening can be compensated for by forming appropriate locking surfaces on the outer circumference of the shaft 14. In any event, however, the effectiveness of the inside portion 47 of the interface 16 as locking means would be reduced by excessive contraction. In contrast, the preferred embodiment provides that the fit between the disc 13 and the shaft 14 at the inside portion 27 of the interface 16 is a very close interference fit. In order to accomplish this, the shaft 14 is pre-heated to an elevated temperature prior to forging so that during forging, the shaft 14 remains at an elevated temperature.
As mentioned, supra, the shaft 14 must be below a temperature of plasticity. In the preferred embodiment, the shaft 14 is heated to 650° C. (1200° F.). This temperature may very, although the temperature of the shaft 14 should be below approximately 815° C. (1500° F.) during the forging of the disc 13 in order to avoid the deformation of the shaft 14 at the interface 16. Such deformation must be avoided to the extent that the integrity of the lock between the disc 13 and the shaft 14 would otherwise be compromised. By forging the turbine wheel assembly 11 with the shaft 14 heated to 650° C., the shaft 14 contracts when the turbine wheel 11 is cold after forging the disc 13. Thus, even though the disc 13 has contracted, the contraction of the shaft 14 insures that an interference fit exists between the disc 13 and the shaft 14 at the inside portion 27 of the interface 16. This also places tensile stress on the steel shaft 14 rather than on the titanium disc 13.
As is well known to those skilled in the art of metallurgy, the component materials which form the shaft 14 and disc 13 tend to oxidize considerably when heated for the forging operation. While this creates some problems in the case of the steel shaft 14, these problems of oxidation are significant in the case of the titanium which is heated to a temperature of plasticity. For this reason, it is common to use a die lubricant whose primary functions are to inhibit oxidation and prevent the fusion of a forged material with a die. In the case of titanium, a suitable lubricant would be Apex Precoat 2000, manufactured by Apex Alkali Products Company of Philadelphia. This is a ceramic pre-coating, which is normally applied by dip application and dried prior to a furnace heating cycle. The steel shaft 14 would also be protected by a suitable die lubricant. Apex Precoat 306 compound from the aforementioned Apex Co. is a preferred material for such purposes, even though the pre-coat material was originally designed for the protection of titanium. Apex Precoat 306 is a liquid dip coating of resins and colloidal graphite. Unfortunately, both Apex Precoat 2000 and Apex Precoat 306 are unsuitable for use at the interface 16 because of the solid materials which would be left behind. The Apex Precoat 2000, in particular, leaves a ceramic residue, which would cause fretting or abrasion at the interface 16. While the graphite residue of Apex 306 would create less problems, such a material has a potential for increasing dissimilar metal corrosion at the interface 16. The present invention contemplates the titanium billet 23 being coated with a non-ceramic die lubricant at a bottom surface 30 of the billet 23 corresponding to the interface 16 at the disc 13. The use of ceramic and graphite lubricants on the steel shaft 14 at the interface 16 is preferably also avoided.
The non-ceramic die lubricant is coated onto the bottom surface 30 of the billet 23. In the preferred embodiment, the non-ceramic die lubricant is a boron nitride (BN) coating, sold by the Carbondum Company, Graphite Products Division, of Niagara Falls, N.Y., as an aerosol spray in an inorganic binder. The boron nitride can also be applied by airless spraying equipment and by other methods. It has a hexgonal crystalline structure, resembling that of graphite, but is considered to be a dielectric material.
It has been found that the boron nitride coating oxidizes or otherwise changes at approximately 700° C. (1300° F.) when heated in an oxidizing atmosphere. After the change, the boron nitride coating becomes crusty and flaky, thereby making it unsuitable for protecting the surface of the metal onto which the boron nitride is coated. It has been found that by heating the boron nitride in an inert atmosphere to a temperature of 925° C. (1700° F.) for twenty minutes, the boron nitride coating changes properties and thereafter can be heated in an oxidizing atmosphere in preparation for forging without deteriorating. Instead of becoming crumbly, the boron nitride coating, which is white in appearance when originally coated onto metal parts for forging, changes to a dark grey or black finish and does not become crusty or flaky. The black boron nitride has the texture and appearance of graphite powder and the outer surface of the coating easily rubs off on one's hands when touched.
The boron nitride coating, after having been preheated in an inert atmosphere, remains as it emerged from having been heated in the inert atmosphere and does not become crusty and flaky when it is later preheated in a oxidizing atmosphere prior to forging. Since the boron nitride coating tends to oxidize at above 700°, it is believed that a transformation takes place in the boron nitride at approximately that temperature, and that this change results in the boron nitride coating assuming the change from white to black when heated in the inert atmosphere. We have found that the black boron nitride finish no longer becomes crusty or flaky when preheated, which leads us to believe that whatever transformation takes place with the boron nitride coating is permanent as far as preventing the change of the coating to a crusty or flaky finish at forging temperatures. Despite these changes, the boron nitride coating retains its hexagonal crystalline structure, although there may be more impurities within the crystalline structure of the black boron nitride.
In the preferred embodiment, the metal parts, after having been coated with the boron nitride coating, are heated in an inert atmosphere of argon gas for twenty minutes. Presently the most preferred temperature range for heating the boron nitride coated part in the argon atmosphere is 925°-955° C. (1700°-1750° F.). The minimum temperature to which the material must be heated in the inert atmosphere is believed to be over 600° C. (1050° F.), or approximately 700° C., although this has not been verified. The maximum preferred temperature for heating a titanium billet with a boron nitride coating in the inert atmosphere would be below 1150° C., at which temperature the titanium would recrystallize to become brittle. While an inert atmosphere is used in the preferred embodiment, it is anticipated that a reducing atmosphere could also be used for heating the boron nitride coated billet so as to change the coating from the white state to the black state. It is also anticipated that the step of changing the coating from white to black can be combined with the pre-forging preheat step.
The steel shaft is preferably protected at the interface 16 by metal plating. At present, electroless nickel plating is used, although other types of plating may be necessary if metallurgical tests or microscopic examinations indicate that corrosion to the interface 16 becomes a problem. Regardless of the specific plating used for the steel shank 14, the combination of the nonceramic bottom surface 30 with the plating of the interface portion 16 of the shaft 14 is used to provide a secure and lasting joint between the disc 13 and the shaft 14. The plating is also intended to diminish dissimilar metal corrosion at the interface 16.
As indicated supra, the preferred temperature for heating the titanium billet 23 for forging is 1100° C. It has been found that at temperatures about 1150° C. (2100° F.), the titanium becomes brittle. At temperatures below 925° C. (1700° F.), the titanium is not plastic enough to render a suitable forged part. The preferred temperature range is, therefore, between 980° C. and 1100° C. (1800° F. and 2000° F.). As indicated supra, the shaft 14 is preferably heated to approximately 650° C., with 815° C. being an approximate temperature at which significant deformation may take place during the forging operations. Since the titanium billet 23 is at a higher temperature, the temperature of the shaft 14 must be initially lower than that of the maximum temperature of no significant deformation. The minimum temperature for the shaft is ambient, although the aforementioned problems of relative expansion and contraction would result in an unstable joint if the shaft 14 is not pre-heated.
After the billet 23 is forged into the disc 13, the resulting turbine wheel 11 is then machined as indicated on the left side of FIG. 1. The final machining of the shaft 14 after forging the disc 13 causes the shaft, which has more material before machining, to have more structural rigidity during forging and nullifies any effect which the forging operation may have on surfaces on the shaft 14. As can be seen, the resulting configuration avoids the use of extra materials in the final machined product. The extra materials would normally be required for fixing the disc 13 to the shaft 14 if fasteners were used.
Referring to FIG. 3, a power transmission shaft 33 is shown in which an aluminum center tube 35 is connected to a titanium diaphragm pack 36. The diaphragm pack 36 is connected to the center tube 35 by means of a transition ring 37. An outer part 40 is made of aluminum and is joined to a titanium inner part 41. The center tube 35 is welded to the transition ring 37 at the outer part by appropriate welding techniques. Likewise, the diaphragm pack 36 is welded to the transition ring 37 at the titanium inner part 41, so that the welded joints are being between two like metals.
In order to form the transition ring, the outer part 4 is first formed, as by forging. An inner surface, which will become an interface 43 between the inner and outer parts 40, 41, is then machined with locking keyways 45 being bored along the surface of the interface 43. The outer part 40 is then coated with Apex Precoat 306 except at the interface 43. The interface 43 is coated with boron nitride. A titanium billet (not shown) is prepared by coating those surfaces which will appear at the interface 43 with boron nitride. The remaining surfaces of the titanium billet are coated with Apex Precoat 2000.
As stated supra, the boron nitride coating is preheated in the inert atmosphere in order to change the boron nitride coating from the white state to the black state.
The outer part 40 is pre-heated to approximately 150° C. (300° F.). The titanium billet is heated to approximately 1100° C. (2000° F.) and inserted on a lower die form (not shown). When resting on the lower die form, the titanium billet is surrounded by the outer part 40 so that the interface portion 43 of the outer part 40 faces the billet. The billet is then forged to form the inner part 41, and is thereby locked into place against the outer part 40 to form the transition ring 37. The transition ring 37 is then machined into its final shape. After being machined, the transition ring may be welded to the center tube 35 and the diaphragm pack 36 as indicated.
The temperature range for the titanium billet which forms the inner part 41 is the same as the temperature range for billet 23 forming the disc 13 in the turbine wheel 11. The temperature range for the aluminum outer part 40 is different from that of the steel shaft 14, but it is still determined by the same criteria. In other words, the ideal temperature range for the aluminum outer part 40 is determined by the minimum temperature required to ensure a sufficiently tight fit at operating temperatures and by the maximum temperature at which the aluminum will retain its structural integrity. For the construction of the transition ring 37 described, a hoop stress in the aluminum outer part 40 is created, which insures a tight joint but yet does not significantly reduce the torque-carrying capability of the transition ring 37. While an estimate of the appropriate temperatures for the component parts can be made for a given fit, the final temperatures must be determined empirically because the ability of the materials to transfer heat at their boundaries during the forging operation is difficult to calculate. The aluminum outer part 40 is preferrably heated to 150° C. (300° F.). A preferred temperature range for the aluminum would, therefore, be between ambient and up to 230° C. (450° F.). It is anticipated that the temperature for the aluminum part may be up to 550° C. (1020° F.).
The foregoing were examples of the inventive process being applied to construct exemplary products. Clearly, numerous variations can be made to the steps described herein while remaining within the spirit of the invention. For this reason, it is desired that the invention be limited only by the claims.
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A mechanically rigid joint is formed between two different metals by completing the joint in a forging operation. A part (14) made of one metal is placed in a die form (20) and is maintained at a temperature below that required for forging. A billet (23) made of the material from which the second part (13) is to be formed is coated with boron nitride at an interface (16). The boron nitride is thermally treated while on the billet (23) by heating the coated billet (23) in a non-oxidizing atmosphere. The billet (23) may then be heated and placed in the die (20) so that the billet (23) can be formed into the second part (13), engaging the first part (14) at an interface (16) defining the joint. The joint (16) is stabilized by providing suitable coatings for the materials, particularly at the interface (16).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to varistors and more specifically to varistors having high energy absorption.
2. Summary of the Prior Art
Varistors having high energy absorption capabilities are difficult to fabricate. This difficulty is due to the complex chemical nature of the varistor mixture. Varistors are mainly composed of zinc oxide in combination with selected quantities of Bi 2 O 3 , Sb 2 O 3 , Co 3 O 4 , MnO 2 , SiO 2 and smaller levels of B, K, or Na, and Al 2 O 3 . Energy is absorbed in the varistor by Joule heating with the ZnO grains acting as heat sinks.
Increasing the grain size to increase energy absorption through traditional ceramic procedures of extending sintering times or higher sintering temperatures is possible, but other electrical properties are adversely affected. Additionally, the varistor may lose portions of the key constituents due to their volatile nature at high sintering temperature. Components of the mixture that are lost at higher sintering temperatures include Sb 2 O 3 , B, K and, in particular, Bi 2 O 3 . Loss of these materials results in an increase in porosity of the disc, causing the maximum energy absorption to be reduced. Stated alternatively, a particular time/temperature combination produces maximum absorption, with a decrease in absorption occurring with either higher sintering temperature or reduced processing time.
In order to overcome the detrimental effects of extending sintering time, a more refractory chemical composition was desired which would tolerate the higher processing temperatures required to grow the larger ZnO grains. In addition, the chemical composition needed to be such that the other electrical parameters of the varistor were not degraded. The disclosed invention meets these requirements.
SUMMARY OF THE INVENTION
The invention comprises a varistor having increased energy absorption. The energy absorption is achieved by utilizing a specific critical combination of key materials which permit an increase in the sintering temperature time without degrading the other parameters of the varistor.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing of a typical varistor.
FIG. 2 is a curve illustrating the voltage current characteristics of a typical varistor.
DETAILED DESCRIPTION
As is well known in the prior art, the process of constructing varistor discs requires the materials used in forming the disc be ground and combined to form a mixture. Portions of the mixture are pressed into the desired shape and sintered in an oxygen atmosphere to form a ceramic disc. Leads are attached to the disc to provide for electrical connection and suitable packaging is provided to complete the varistor.
A typical varistor is illustrated in FIG. 1. It includes the varistor disc 10 which has electrodes, 10 and 12, affixed to the opposed sides thereof. Leads, 16 and 18, are attached to the electrodes provide means for connecting the varistor into the electrical circuit.
At a low voltage stress, the current flowing through the varistor is low and the characteristic is essentially linear. As the voltage stress increases above a selected point, the current increases at a very rapid rate. In application, the characteristics of the varistor disc are selected such that at the operating voltage stress, the current through the varistor is low (typically less than 0.5 ma/cm 2 .) However, with voltage or current surges which increase the voltage stress to which the varistor is subjected, the current increases very rapidly, dissipating high levels of energy and limiting the aptitude of the voltage surge. The voltage/current characteristic of a typical varistor is illustrated in FIG. 2.
Functioning of the varistor to limit transients is dependent on absorbing energy. Thus, it is clearly desirable that the energy absorption of the varistor material be as high as practical. In prior art varistors, the energy absorption per cubic centimeter was typically less than 500 J/cc. It is desirable to increase this energy absorption, thus reducing the size of varistor discs for a particular application.
The varistor which is the subject of this patent application provides a varistor disc having high energy absorption coupled with good electrical characteristics.
In developing the varistor which is the subject matter of this patent application, the materials comprising the mixture were prepared by the normal practice of milling, spray drying, pressing the disc, and sintering at a temperature of 1300° C. for two hours. After sintering, the discs were lapped, annealed at 600° C. for two hours, the electrodes were applied and the varistors were electrically tested.
The basic electrical parameters were measured by subjecting the disc to a voltage stress of E 0 .5 and measuring the parameters at room temperature. (E 0 .5 is the voltage stress at which a current of 5 ma/cm 2 flows.) The energy absorption was obtained by subjecting the disc to a 60 Hz voltage at E 1 .1 until failure with the energy absorption was recorded. The high temperature stability was measured by subjecting these varistors to a temperature of 250° C. at a voltage stress of 0.7 E 0 .5 and measuring the time required for the current to increase to 5 mA/cm 2 .
In service, the discs are continuously subjected to line voltage and will operate at some temperature slightly above ambient due to the leakage current heating. After passage of a transient power surge, the leakage current is slightly higher due to the temperature dependence of the V/I characteristic. It is necessary that the disc remain thermally stable during this time period so that the heat from the surge can be dissipated without the varistor exhibiting an uncontrolled increase in leakage current, leading to a failure. The high temperature stability test at 250° C. provides a measure of this stability of the varistor during intervals of high energy absorption. The reported high temperature stability intervals is the time required for the varistor current to reach 5 Ma/cm 2 at the specified test conditions.
In developing the varistor comprising the invention, varistor mixtures including varied amounts of Bi 2 O 3 , Sb 2 O 3 , SiO 2 , MgO and CaO and smaller amounts of other ingredients were constructed and electrically tested. Each of these mixtures was given an arbitrary identification number with the results of the these tests tabulated below. The room temperature leakage current, RTiR, and the non-linearity exponent (alpha) measured between 0.5 ma/cm 2 to 250 A/cm 2 are important varistor characteristics and are also shown in the table.
__________________________________________________________________________ Bi.sub.2 O.sub.3 Sb.sub.2 O.sub.3 SiO.sub.2 MgO CaO E.sub.0.5 R.T. iR STAB ENERGYComp m/o m/o m/o m/o m/o v/cm uA/cm.sup.2 Mins J/cm.sup.3 ALPHA__________________________________________________________________________963 1.0 1.5 0.5 0.5 0.05 1404 5.9 88 777 24941 1.0 1.0 0.5 0.5 0.05* 1232 4.8 125 539 24931 1.0 1.0 0.5 0.5 0.05 1198 5.3 350 833 24964 1.0 1.0 0.25 0.5 0.05 1180 5.7 209 1167 23__________________________________________________________________________ *0.01 m/o BaO added (m/o = mole percent)
Based on the results, it is clear that the mixture in accordance with the invention (labeled) allows a reduction in the Sb 2 O 3 level and produces a varistor having high energy absorption capability. A reduction in the SiO 2 content is also necessary in order to achieve the indicated performance.
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A varistor utilizing a disc of mainly ZnO in combination with preselected combinations of Bi 2 O 3 , Sb 2 O 3 , SiO 2 , MgO and CaO.
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This application is a continuation of pending International Patent Application No. PCT/EP2003/014499 filed Dec. 18, 2003 which designates the United States and claims priority of German Patent Application No. 102 60 597.1 filed Dec. 23, 2002.
FIELD OF THE INVENTION
The present invention relates to a brake mechanism for a disk brake to create and transmit a clamping force by way of a brake pad to a brake disk.
From existing technology there are several known elements for brake mechanisms for disk brakes, which are relatively compact, stable, and reliable and can be produced in mass quantities especially for heavy trucks.
For instance, EP 0271864 B1 describes an activation device in which an axial activation member is positioned in a brake caliper housing around which several components of the brake mechanism are arranged. The adjustment device provided for this and the applied reinforcing mechanism in the form of a roller-ramp appliance include a number of individual components which make installation difficult and therefore prove costly. In addition, in connection with the installation of the brake caliper used with this disk brake, it is necessary, both on the rear side of the brake caliper housing and on the side toward the brake disk, to provide many apertures which, however, involve extensive insulation problems.
In addition, EP 0553105 B1 describes a brake mechanism which includes a gear mechanism to transmit the clamping force. Although this brake mechanism is less complex than the aforementioned model, its installation in the brake caliper housing proves difficult because during the assembly inside the housing a pivot connection must be established and maintained between a contact piece and the gear by means of a roller body that must be arranged between these. In addition the brake mechanism produced in this manner can be inserted only from the rear of the brake caliper, requiring a somewhat large aperture in the rear part of the brake caliper housing or even a two-part brake caliper with a divider included, which inevitably raises considerable insulation problems. In addition, as a consequence of the exclusively pivoting connection between the gear and the contact piece, the contact piece, lacking the extra required kinematic degree of freedom, engages the brake shoe at a slight inclination, so that uneven wearing occurs on the brake pad.
To avoid the aforementioned problem, it is proposed in the known technology, for instance in EP 0698749 B1, to make available with a gear-activated brake mechanism, such as additional degree of freedom so that a strictly axial linear arrangement of the contact piece becomes possible. The brake mechanism presented in this publication is introduced during installation both from the brake disk side and from the side of the brake caliper turned away from the brake disk, and is assembled inside the brake caliper, which again involves insulation problems as a result of the numerous apertures. In addition, this type of installation proves complex and therefore costly.
WO 01 75324 describes a brake mechanism in which the contact element for transmitting the clamping force is arranged around a center rod. In the presented configuration of the brake mechanism, however, a number of individual components are used, which must interact in complex ways. In this connection, the installation of the individual components proves especially time consuming and thus costly.
This description of existing technology shows the need to find solve the various associated problems and disadvantages as simultaneously as possible.
It is therefore the object of the present invention to provide a brake mechanism that relies on fewer components and that proves less complex than the devices known in existing technology. This is intended to include less of a space requirement and reduced weight. In addition, the brake mechanism should be distinguished by improved stability and, because it is built into a brake caliper housing, by improved insulation. An additional object consists in providing a brake mechanism that is easily installed and whose individual components can be produced easily and cost-effectively.
This object is fulfilled through a braking mechanism for a disk brake for transmitting a force onto a brake block which acts on a brake disk, where the brake mechanism is engaged in a brake caliper of the disk brake and includes a contact element interacting with the brake block and a rod, characterized in that the contact element is installed in the housing of the brake caliper parallel to the rotational axis of the brake disk with the help of the rod.
An essential advantage of the invention consists in the fact that the rod that runs through the contact element serves as the means of installing this contact element in the housing of the brake caliper, so that the rod and thus the contact element surrounding it are positioned parallel to a rotation axis of the brake disk.
For this purpose the rod is configured in such a way that it can be secured axially in the housing of the brake caliper.
In one embodiment the contact element on the brake disk side has a hollow inner section into which the rod extends.
According to the invention, the rod interacts with a reset device which returns the brake mechanism to the starting position if there is no longer a clamping force acting on the brake disk. Thus one advantageous configuration of the brake mechanism provides that the reset device, preferably a coil spring activated by pressure, is positioned in the hollow inner section of the contact element between the brake-disk end of the rod and the contact element.
Alternatively it is also conceivable that the reset device is positioned inside the brake caliper housing in such a way that this device operates either between the housing of the brake caliper and the contact element, or between the housing of the brake caliper and the reinforcing mechanism acting directly or indirectly on the contact element.
In another embodiment of the brake mechanism according to the invention, the contact element is at least of two-part construction and includes a sliding sleeve and an adjusting screw that are linked together by a threaded connection.
The adjusting screw serves to compensate for wearing of the brake linings caused by the locking.
There are essentially two possible arrangements for the construction of the contact element according to the invention.
In one embodiment the sliding sleeve is in line with an aperture of the brake caliper housing and has an inner thread with which an outer thread of the adjusting screw is screwed rotatably. To allow relative movement of the sliding sleeve during the adjustment process, the sliding sleeve is controlled in the brake caliper so that it cannot be rotated.
In another embodiment the adjusting screw is rotatably controlled in an aperture of the brake caliper housing and has an inner thread with which an outer thread of the sliding sleeve connects, so that the sliding sleeve must also be kept secure against rotation, which can be achieved for instance through the direct or indirect coupling of the sliding sleeve with the brake block or brake lining carrier.
In both embodiments the adjusting screw on the brake disk side has the hollow inner section into which the rod extends and into which the reset device can be positioned, so that in both cases the sliding sleeve extends beyond this hollow inner section.
In the foregoing preferred embodiments the sliding sleeve and adjusting screw components are mounted so that they rotate axially around the rod. To obtain an optimal control and positioning of the individual components in the brake caliper, the rod is positioned so that it can rotate in the brake caliper housing, preferably in the rear area of the housing.
The rod in this case is in a mutually non-rotatable connection with the adjusting screw, which however allows linear sliding of the adjusting screw on the rod. In other words the rod serves as a rotatable mounting for the adjusting screw.
In another embodiment of the brake mechanism, in addition, an adjustment device is provided which powers the adjusting screw for the purpose of replacement. The adjustment device and its individual components can either be configures likewise as axially symmetrical and thus placed around the rod, or they can be situated separately on the brake caliper housing and connected with the adjusting screw.
The structure of the contact element consisting of the sliding sleeve and adjusting screw and possibly of the adjustment device as axially symmetrical components can easily be processed mechanically and therefore are less costly to produce. In addition, because of the primarily axially symmetrical structure, altogether a more compact and thus more stable brake mechanism is created, which first is marked by a shortened structural length in the axial direction to the brake disk and second, for its control and its installation in the housing, also requires only an aperture that is axially symmetrical in configuration and which is easily processed and simple to produce by casting and allows simple insulation.
In an additional embodiment of the brake mechanism according to the invention, the rod is configured so that it axially, that is with respect to the brake disk, grasps and secures the reinforcement mechanism, which acts on the adjustment device and/or the adjusting screw and/or the contact element when the brake is activated. Parts at least of the reinforcing mechanism can also be produced as axially symmetrical.
The reset device provided inside the hollow inner section of the contact element or of the adjusting screw is, in one embodiment according to the invention, also capable of exerting a definite force on the adjusting screw while forming a borderline torque, so that as a result any inadvertent vibration-induced rotation of the adjusting screw is prevented.
Because, according to the invention, the rod is configured as a shaft mounted rotatably in the housing of the brake caliper and is connected securely against rotation by the adjusting screw with the contact element, in a simple manner it becomes possible to manually adjust the entire brake mechanism after installation in the brake caliper, in that it is possible for this purpose to directly or indirectly attack at least one of the ends of the rod which is free.
In another advantageous embodiment of the invention, the end of the sliding sleeve pointing toward the brake disk and interacting with the brake block or the brake lining carrier is completely closed, so that most of the brake mechanism, especially the hollow inner section of the adjusting screw of the contact element, can already be protected from soiling. Between the contact element and the brake caliper housing, therefore, just one simple, preferably ring-shaped insulating means must be provided.
In an adaptation of the invention the rod is configured in such a way that it is capable of holding together the contact element with the sliding sleeve and the adjusting screw and/or the reset device and/or the adjustment device and/or the reinforcing mechanism as a self-sufficient unit. Depending on the configuration, this allows on the one hand the joint construction as a pre-assembled unit and its subsequent insertion into the brake caliper housing or, on the other hand, the pre-assembly of individual components and their subsequent joint construction inside the brake caliper, so that depending on the circumstances the building components or individual parts can be inserted through apertures provide din both sides of the brake caliper.
The centrally positioned rod according to the invention is capable of fulfilling several functions.
On the one hand it serves as an installation tool and an essential element for the self-sufficient unit, and on the other hand it is the means for securing this unit inside the brake caliper housing. In addition it serves as a rotation bearing axle around which the rotary components of the brake mechanism can rotate.
Because, in one embodiment, the rod is in direct connection with the adjusting screw of the adjustment device, a wear detection sensor of any desired construction type can act directly or indirectly on these and is capable of determining the wear of the brake lining by means of the particular manner of rotation of the adjusting screw.
An essential advantage of the brake mechanism in each of the previously described embodiments according to the invention consists in the diverse ways in which it can be used.
Thus, it can be built into disk brakes of both the fixed-caliper and the floating-caliper type. Because of its compact configuration it can be used both for one-part and for multiple-part brake calipers. The use of the centrally positioned rod is essentially independent of the concretely used configuration of the reinforcing mechanism and of the realization of the adjustment device. Thus, electrical, pneumatic, or hydraulic activation means can be provided for the purpose of driving the reinforcing mechanism. This mechanism itself can include a gear with eccentrically arranged transmission section, a roller-ramp mechanism, a wedge arrangement, or the like.
As such, the brake mechanism according to the invention can be provided as a single component in the brake caliper housing, so that under some circumstances it includes a means of uniformly distributing the clamping force on the contact element, or there can be two brake mechanisms of this kind arranged parallel in the brake caliper housing, which simultaneously act on the brake block so that in some cases the adjustment device of these can be coupled in the brake mechanisms by means of a synchronization means.
Additional advantages and embodiments of the brake mechanism according to the invention can be seen from the embodiments that are described with reference to illustrations are not intended to be restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic view of the brake mechanism according to the invention with its essential main components.
FIG. 2 shows the brake mechanism in a particularly preferred embodiment according to the invention.
FIG. 3 shows schematically an additional embodiment of the brake mechanism with an external adjusting screw.
FIG. 4 shows schematically an embodiment of the brake mechanism with an external adjusting screw in connection with a separately mounted adjustment device.
FIG. 5 shows schematically an embodiment of the brake mechanism with an interior adjusting screw in connection with a separately mounted adjustment device.
FIG. 6 shows schematically an additional embodiment of the brake mechanism with a reset device mounted between the brake caliper and the reinforcing mechanism.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows schematically the basic structure of the brake mechanism that is the basis of the invention. The components shown in FIG. 1 are presented only in theoretical depictions.
The brake mechanism according to the invention is contained in a housing of a brake caliper 1 . The brake mechanism includes essentially a contact element 2 , which can move axially as far as the brake disk (not illustrated) and interacts with a brake block (also not illustrated) or brake lining carrier in order to transmit the clamping force.
In the embodiment shown in FIG. 1 the contact element 2 consists of an exterior sliding sleeve 3 , which is guided not in rotary manner but rather linearly in the housing of the brake caliper 1 . In addition the contact element 2 has an adjusting screw 4 , which is positioned inside the sliding sleeve 3 , and is connected by a threaded link with it. The adjusting screw 4 has an inner hollow section 5 at its end that is turned toward the brake disk.
The sliding sleeve 3 and the adjusting screw 4 are configured as axially symmetrical.
The adjusting screw 4 of the contact element 2 has a rod 6 running through it, which ends at the hollow inner section 5 . The rod 6 is axially positioned in the housing of the brake caliper 1 , in its rear area.
The adjusting screw 4 is activated by an adjustment device 7 , which is also configured as axially symmetrical in the embodiment shown in FIG. 1 and has the rod 6 running through it. The rod 6 itself is positioned rotatably in the housing of the brake caliper 1 and is in rotation-proof connection with the adjusting screw 4 .
To compensate for the vacant space between the brake lining and the brake disk that has been enlarged by wearing of the brake disk, the adjustment device 7 is activated in order to set the adjusting screw 4 in rotation so that the contact element 2 slides axially in the direction toward the brake disk to compensate for this additional vacant space before the actual clamping occurs during braking.
The rod 6 interacts with a reset device 8 , which in this embodiment of the brake mechanism is positioned in the hollow inner section 5 of the contact element 2 and acts on the adjusting screw 4 .
To transmit the clamping force, the contact element 2 is activated by a reinforcing mechanism 9 , which also has the rod 6 running through it. The reinforcing mechanism 9 serves to strengthen a force applied from without, for instance from a hydraulic or pneumatic cylinder.
In the embodiment according to the invention the rod 6 holds together the contact element 2 with the sliding sleeve 3 and the adjusting screw 4 , the adjustment device 7 , the reset device 8 , and the reinforcing mechanism 9 as one unit in axial direction in the housing of the brake caliper 1 .
FIG. 2 shows the schematic principle of the brake mechanism presented in FIG. 1 , now in a concrete preferred embodiment.
The self-sufficient unit consisting of the contact element 2 , the adjustment device 7 , the reset device 8 , and the reinforcing mechanism 9 is held together by the rod 6 , which is rotatably positioned in the rear area of the one-part housing of the brake caliper 1 .
The reinforcing mechanism 9 includes a gear 10 , on which an activation cylinder (not illustrated) strikes through an aperture in the brake caliper 1 to apply a force. The gear 10 can swivel around a cylindrical roller body 11 , which has the rod 6 running through it and is secured immovably by means of a securing ring 12 axially on the rod 6 , so that the roller body is supported flatly on the rear wall of the brake caliper 1 .
The rod 6 itself is axially and rotatably secured in the housing of the brake caliper 1 , first through the securing ring 12 and second by a securing ring 13 situated externally on the rear wall opposite this securing ring 12 .
The gear 10 in its lower section with a concave mounting surface is in contact with the roller body 11 by means of a first radial segment bearing 14 .
With its opposite convex mounting surface, the gear 10 is in connection with a transmission element 16 by way of a second radial segment bearing 15 .
The lower end of the gear 10 is configured so that a reinforcement of the introduced force can be achieved in that the gear 10 moves between the two radial segment bearings 14 and 15 and thereby pushes the contact element 2 in the direction of the brake disk.
The gear 10 and the radial segment bearings 14 and 15 have a slit opening through which the rod 6 extends. In the same way the roller body 11 and the transmission element 16 are provided with a bore hole for inserting the rod 6 .
The transmission element 16 is in direct connection with the adjustment device 7 and the adjusting screw 4 of the contact element 2 .
The adjustment device 7 consists of several axially symmetrical components, an adjustment ring 17 , a torque-limiting spring 18 , a locking spring 19 acting only in one rotation direction, and a housing ring 20 . A stud (not illustrated) extends from the convex mounting surface of the gear 10 and engages in a groove situated externally on the adjustment ring 17 (not illustrated) and, through the swivel motion of the gear 10 , sets the adjustment ring 17 in motion. By means of the torque-limiting spring 18 and the housing ring 20 , this rotation is transmitted to the locking spring 19 and thus to the adjustment screw 4 until the contact element 2 grips the brake disk with the brake block (not illustrated) brake lining carrier. At this time the torque-limiting spring 18 slips and the transmission element 16 can completely transmit the power onto the contact element 2 .
The adjusting screw 4 rotates during replacement with the rod 6 .
For this purpose the screw is in a rotation-proof connection with the rod 6 , a connection that is produced by an outer hexagon 21 which is received in a corresponding guide groove that is configured with an inside hexagon, which during the actual tensing allows the adjustment screw 4 to glide on the outside hexagon 21 and thus on the rod 6 .
The reset device 8 in the form of a bolt spring activated by pressure is situated between the adjustment screw 4 and the rod 6 . For this purpose an abutment plate 22 is secured on the brake disk end of the rod 6 for the bolt spring 8 by means of an insulating ring 23 . The spring force of the reset device 8 is selected here so that it allows automatic resetting of the entire unit on the one hand, after no more clamping force is exerted, and on the other hand in the rest position it exerts such power on the adjusting screw 4 that this screw cannot be inadvertently set in rotation, for instance as a result of vibrations. In other words, the spring 8 functions in this context also as protection against vibration for the adjustment screw 4 .
The end 24 of the rod 6 placed opposite the bake disk is exposed in a recess in the rear wall section of the brake caliper 1 and is configured in such a way that, by means of a tool, it allows manual adjustment of the entire unit by the connection that transmits the rotation between the rod 6 and the adjusting screw 4 .
The contact element 2 on its side directed toward the brake disk is closed off with a lid 25 so that the internal hollow section 5 is protected against soiling from outside. The sliding sleeve 3 of the contact element 2 is connected with the brake block by a stud 26 and thereby remains locked against rotation, so that the sliding sleeve 3 can move in an axially symmetrical bore hole of the brake caliper 1 only by sliding in a linear direction.
Between the sliding sleeve 2 and the brake caliper 1 there is an O-ring 27 on the inside for purposes of insulation. In addition, on the outside between the sliding sleeve 3 and the brake caliper 1 , there is an insulating means 28 in the form of a bellows.
It is recognized that, through the use of primarily axially symmetrical components, which are held together by the rod 6 inside the brake caliper 1 and are installed in the caliper, an extremely compact and self-sufficient brake mechanism can be created.
The brake mechanism shown in FIG. 2 , however, is not restricted to this embodiment. Rather, further variants on the inventive principle are possible.
Thus, in FIG. 3 , we see an additional embodiment of the brake mechanism, in which the adjusting screw 4 is guided rotatably in the housing of the brake caliper 1 , and where the sliding sleeve 3 is located inside the adjusting screw 3 . The adjustment device 7 functions on the same principle as the embodiment shown in FIGS. 1 and 2 .
An alternative to an adjustment device 7 , which is not positioned axially symmetrically around the rod 6 , is seen in FIG. 4 . This adjustment device 7 includes a positioning element 29 , such as a positioning motor, and a gear wheel 30 , which interlocks by a threading with the adjusting screw 4 in order to set this wheel in motion accordingly.
In the embodiment shown in FIG. 4 the adjusting screw 4 , as in FIG. 3 , is positioned around the sliding sleeve 3 and is controlled in the brake caliper 1 . The embodiment according to FIG. 1 is also possible, whereby the sliding sleeve 3 does not extend over the entire length of the adjusting screw 4 , as is shown in FIG. 5 , so that a threaded connection with the gear wheel 30 is possible.
In the embodiment according to FIG. 5 the reset device 8 is located between the brake caliper 1 and the pressure element 2 , or the sliding sleeve 3 . It is also possible, however, that, as shown in FIG. 6 , the reset device 8 is situated between the brake caliper 1 and the reinforcing mechanism 9 .
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The invention relates to a brake gear for a disc brake serving to transfer a force to a brake pad that acts upon a brake disc. The brake gear is accommodated in a brake caliper of the disc brake and comprises both a pressing element, which interacts with the brake caliper, as well as a rod. The pressing element is mounted in the housing of the brake caliper with the aid of the rod in such a manner that it is parallel to the rotation axis of the brake disc.
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This application is a continuation of our prior U.S. application Ser. No. 243,082 filed Mar. 12, 1981, and now abandoned.
BACKGROUND OF THE INVENTION
This invention is directed to a process for the conversion of hydroperoxides present in allyl-alkyl ether to enhance the use of such ether as a feedstock in a rhodium catalyzed hydroformylation process to produce the corresponding ether aldehyde. Such hydroperoxides are decomposed by treating the ether with metal hydride to give products which include α,β-unsaturated aldehydes, which are then reduced to the corresponding alcohols.
Hydroperoxides, which may form in allyl-alkyl ether by adventitious air oxidation, decompose during hydroformylation to form α,β-unsaturated aldehydes such as acrolein, among other by-products. The effect of acrolein and closely related compounds as rhodium catalyst inhibitors is known in the prior art. U.S. Pat. No. 4,148,830 issued Apr. 10, 1979, indicates, at Column 4 lines 65 et. seq., that it is highly desirable to maintain "substituted acrolein II" (i.e., ethylpropylacrolein) at low concentrations "since it has been observed that a build-up of this product tends to curtail the life of the rhodium complex catalyst."
The effect of the presence of acrolein in allyl-alkyl ether used as a feedstock in a rhodium catalyzed hydroformylation reaction to produce the corresponding ether aldehyde is seen in Example 1 in Table I below. It is postulated that this catalyst induction period occurs because of the competition for the rhodium catalyst between the hydroformylation reaction and the reaction to reduce acrolein to propanol and/or propionaldehyde. Such a catalyst induction period is effectively eliminated by removing hydroperoxides and acrolein from the allyl-alkyl ether. See Examples 2-4, infra, and Table I below.
According to J. A. Riddick and W. B. Bunger, "Techniques of Chemistry" Vol. 2, p. 690 "Organic Solvents" Wiley-Interscience (1970), solutions of phenothiazine, iron (II) sulfate, tin (II) chloride, copper-zinc couple, sodium bisulfite, alkali metal hydroxides, cerium (III) hydroxide and lead (IV) oxide have all been found to destroy peroxides in ethers. However, none of the above reagents is known to be effective in removing or reducing acrolein as well.
Riddick and Bunger, supra at p. 691 also discloses that passing impure ether through an activated aluminum oxide column will reduce aldehyde content as well as remove peroxide. However, research has revealed that only a relatively small quantity of acrolein is adsorbed on the alumina and retained (See Example 2 and Table I below). Thus alumina cannot effectively be used for the purification of large quantities of allyl-alkyl ether without adding complicated and expensive processing steps to avoid eventual acrolein breakthrough with the allyl-alkyl ether effluent.
M. Ross Johnson and Bruce Rickborn "Sodium Borohydride Reduction of Conjugated Aldehydes and Ketones", J. Org. Chem. Vol. 35, p. 1041 (1970) show the use of aqueous alkali metal borohydrides as reducing agents for aldehydes, including the reduction of acrolein to allyl alcohol and propanol. Similarly, British Pat. No. 981,965 describes the use of alkali metal borohydride to reduce the residual aldehyde content in Oxo alcohol after hydroformylation. However, neither reference discloses the use of alkali metal borohydrides to reduce hydroperoxides and simultaneously to reduce the acrolein formed during the reduction of the hydroperoxides in allyl-alkyl ethers.
U.S. Pat. No. 3,003,002 discloses a means of removing peroxides from diethyl ether by contact with a strong base anion exchange resin in its hydroxyl form. However, this treatment will only remove peroxide and will not remove aldehydes, as such bases will not react with α,β-unsaturated aldehydes in such manner as to tie them up.
British Pat. No. 876,034 and U.S. Pat. No. 4,107,099 both disclose the manufacture of borohydride exchange resins. In addition, U.S. Pat. No. 4,107,099 contains several examples of the use of such resins. Example 12 discloses the reduction of crotonaldehyde, as an undesirable impurity in synthetic ethanol, in concentrations of 20 to 500 ppm. Example 15 discloses a qualitative reduction of peroxides in tetrahydrofuran, such reduction being monitored by qualitative analysis employing an iodide test in which an intense red-brown color will indicate the presence of substantial peroxide.
It has now been unexpectedly found that treatment with metal hydrides will convert hydroperoxides in allyl-alkyl ethers to acrolein and other decomposition products not harmful to the hydroformylation reaction, and will then reduce the acrolein to propanol and/or propionaldehyde without reducing the olefinic double bond in the allyl-alkyl ether. The novel metal hydride treatment will eliminate the catalyst induction period present in the hydroformylation reaction when partially oxidized allyl-alkyl ether is employed as a feedstock for conversion to its corresponding ether aldehyde. This is because the treatment will free the rhodium catalyst for the hydroformylation reaction, eliminating the competing acrolein to propanol and/or propionaldehyde reaction. See Table I below.
DESCRIPTION OF THE INVENTION
This invention is directed to a process for the selective reduction, by use of metal hydrides, of hydroperoxides in allyl-alkyl ethers to their decomposition products, including acrolein, and for the reduction of the acrolein produced to propanol and/or propionaldehyde, without reduction of the allyl-alkyl ethers. Thus, this invention is highly useful because acrolein is a rhodium catalyst inhibitor, and propanol and propionaldehyde are not inhibitors.
Allyl-alkyl ether, while being stored, will develop a hydroperoxide content as a result of the adventitious entry of air. These hydroperoxides can be decomposed to form acrolein and other impurities according to the following scheme: ##STR1##
When an allyl-alkyl ether, such as allyl tert-butyl ether ("ATBE"), containing hydroperoxides is used as a hydroformylation reaction feedstock, a catalyst induction period is observed. It is believed that this induction period results from the competition for the rhodium catalyst* between the hydroformylation reaction (k 1 below) and the reduction of acrolein to propanol and propionaldehyde (k 2 below). ##STR2## Thus, the metal hydride treatment eliminates the observed catalyst induction period because the k 2 reaction is eliminated by the prior reduction of acrolein, thereby allowing the rhodium catalyst to effect the k 1 reaction unfettered by the competing acrolein reduction reaction. This is supported by experimental data which shows the induction period is eliminated by the removal of hydroperoxides and acrolein from the ATBE. (See Examples 2-4 in Table I below).
Alumina appears unsatisfactory for the purification of large quantities of ATBE because acrolein is adsorbed rather than reduced. Thus, although experimentation has shown that hydroperoxide and acrolein free ATBE can be produced by passing the ether through an alumina column (see Example 2 in Table I below), such process is not commercially desirable because of the necessity of having to periodically wash the alumina bed free of the adsorbed acrolein and hydroperoxides. In a commercial operation which is operated continuously, one would have to employ multi-columns containing alumina and shift the liquid flow from one to another in order to avoid breakthrough of acrolein and/or hydroperoxide, and then regenerate the beds by washing them free of adsorbed and occluded acrolein and/or hydroperoxide while the beds are not in use.
It was found that treatment with a metal hydride decomposes the allyl-alkyl ether hydroperoxides to acrolein and alkyl alcohol and then further reduces the rhodium catalyst inhibitor acrolein to propionaldehyde and propanol, without reduction of the allyl-alkyl ether according to the following scheme: ##STR3## where MH is a metal hydride.
For this invention, the term metal hydride includes metal containing compounds which contain at least one hydrogen bonded to a metal or a non-metal and which can release the hydrogen by elevation of temperature or by addition of a decomposition agent, viz. acid. Representative metal hydrides include:
alkali metal (Na, Li, K, Cs, Rb) and alkaline earth metal (Ca, Mg, Be) borohydrides. (MBH 4 )
trialkylborohydrides, including
lithium triethyl borohydride [Li(C 2 H 5 ) 3 BH]
lithium tributyl borohydride [Li(C 4 H 9 ) 3 BH]
lithium triisobutylborohydride Li[CH 2 CH(CH 3 ) 2 ] 3 BH
lithium aluminum hydride (LiAlH 4 )
lithium-tri-tert-butoxyaluminohydride [Li(t-BuO) 3 AlH]
lithium-tri-ethoxyaluminohydride [Li(EtO) 3 AlH]
sodium bis (2-methoxyethoxy) aluminum hydride [Na(CH 3 OCH 2 CH 2 O) 2 AlH 2 , Vitride™]
The allyl-alkyl ethers from which hydroperoxides and acrolein may be removed via the novel process are of the formula: ##STR4## wherein Z 1 and Z 2 , each independently of the other, represent a C 1 to C 4 alkyl radical, and Z 3 and Z 4 each, independently of the other, represent a hydrogen atom or a C 1 to C 3 alkyl radical, or wherein Z 1 represents a C 1 to C 4 alkyl radical, Z 2 and Z 3 together with the carbon atoms to which they are attached form a 5-membered or 6-membered cycloaliphatic ring, and Z 4 represents a hydrogen atom or a C 1 to C 3 alkyl radical. Representative allyl-alkyl ethers include:
allyl tert-butyl ether
allyl 2-methylbut-2-yl ether
allyl 2,3-dimethylbut-2-yl ether
allyl 3-methylpent-3-yl ether
allyl 3-ethylhex-3-yl ether
allyl 5-propylnon-5-yl-ether
allyl 1-methylcyclohexyl ether
allyl 1-methylcyclopentyl ether
One preferred embodiment of this discovery involves the use of aqueous sodium borohydride to reduce hydroperoxides and to then reduce acrolein in allyl-alkyl ethers. When ATBE was treated with sodium borohydride, its hydroformylation reaction showed no catalyst inhibition (See Example 3 in Table 1).
Sodium borohydride is preferred to the other above metal hydrides as it is stable in basic water solutions. Moreover, solutions of sodium borohydride in polyethers are available commercially. The alkali trialkylborohydrides are also commercially available in solutions, but are more expensive than sodium borohydride. Lithium aluminum hydride and its derivatives, including Vitride™ are in one respect less favorable than sodium borohydride since they are very reactive with water and alcohols, thereby liberating hydrogen, which is potentially dangerous.
A 2-100 fold molar excess of metal hydride, based on moles of hydroperoxide, should be used to ensure the removal of hydroperoxide. Five to sixty minutes contact time of the borohydride solution with the allyl-alkyl ether is generally sufficient to effect the desired reduction though longer or shorter periods may be used. A borohydride should be used as a solution in a strong base, such as sodium hydroxide, to stabilize the aqueous borohydride as well as to stabilize the allyl-alkyl ether against hydrolysis to allyl alcohol. The concentration of sodium hydroxide can vary from 0.5N to 10N, with a preferred concentration being 1N. At the end of the reaction the ether should be washed with a sufficient amount of deoxygenated water to eliminate dissolved sodium hydroxide and borohydride. The borohydride treatment and particularly the water washings should be done under a nitrogen blanket to avoid air oxidation of the allyl-alkyl ether.
The reduction of hydroperoxide occurs rapidly at room temperature, but the reaction can be conducted at lower or higher temperatures (0° C. to 100° C.) if desired.
The concentration of sodium borohydride may vary within the range of its solubility at the particular temperature, e.g., at room temperature it can vary from 1 g to 55 g of sodium borohydride per 100 g of water.
The metal hydride can be provided in an insoluble form to allow facile separation in a liquid-solid system. This embodiment involves the use of resin immobilized borohydride counterions. According to U.S. Pat. No. 4,107,099, at column 1 lines 65 et seq., the anion exchange resins that are useful for the creation of immobilized borohydride counterions are those that are strongly basic, for example, the crosslinked quartenary ammonium polystyrene anion exchange resins of the gel or macroreticular types.
It was found that immobilized borohydride on Amberlyst™ A-26 anion exchange resin (prepared in accordance with U.S. Pat. No. 4,107,099 to Ventron) (see Example 4 below), was extremely effective in decomposing allyl-tert-butyl ether hydroperoxides and thus in eliminating the inhibitory effects of its decomposition product acrolein on the rhodium catalyst during ATBE hydroformylation. ™Rohm and Haas. When a hydroperoxide-contaminated stream of ATBE was passed through a packed glass column of borohydride-exchanged Amberlyst A-26, the hydroperoxides were destroyed quantitatively and the ATBE that eluted from the column showed no catalyst inhibition in its hydroformylation reaction. See results for Example 4 in Table I below.
For this batch-type embodiment of the invention, the amount of resin to be used is determined by the maximum loading capacity and the amount of peroxide in the ATBE feedstock. U.S. Pat. No. 4,107,099 discloses that the maximum loading capacity is about 3.7-3.8 meq. of boron per gram dry resin for gel type resins (e.g., Amberlite™ IRA-900) whereas loading capacity is 4.1-4.2 meq. of boron per gram of dry resins for macroreticular type resins (e.g., Amberlyst™ A-26). The treatment with the borohydride resin can be done at about room temperature, viz. 23° C., although higher (viz. up to 75° C.) or lower temperatures (viz. down to 0° C.) are also suitable so long as the effectiveness of the treatment is achieved.
A third preferred embodiment of this invention involves the implementation of the immobilized borohydride resins into a system which permits a continuous flow of allyl-alkyl ether, free of hydroperoxides and aldehydes, into a hydroformylation reactor. In this system, a series of guard beds of borohydride resins are included in the process scheme to ensure that the hydroperoxides and aldehydes are removed from the feedstock prior to such feedstock's entry into a hydroformylation reactor. This will protect catalyst activity while avoiding a separate treatment of the feedstock. The final bed in such system consists of an adsorbent, such as another anion exchange resin bed or silica gel, which possesses the ability to trap any boric acid, boride salt or entrained borohydrides in the allyl-alkyl ether effluent and thus avoid any contamination of the main hydroformylation catalyst solution.
As in the second embodiment, above, the amount of resin necessary for this continuous feed system is to be based upon the maximum loading capacity of the resin as well as the amount of hydroperoxide in the allyl-alkyl ether feedstock. Room temperature, about 23° C., is preferable although higher or lower temperatures are also suitable.
Other systems for purification are also possible. Thus, an effective process would comprise (a) treating the allyl-alkyl ether with metal hydride in alkaline aqueous solution; (b) passing the ether effluent through a borohydride resin bed; and (c) washing the ether with sufficient deoxygenated water to eliminate dissolved metal hydride and alkali (e.g., sodium hydroxide).
EXAMPLES
The following general procedure was followed in determining the hydroformylation reaction rate in all the examples below:
Hydroformylation rates were determined in a 100-ml stainless steel autoclave equipped with magnetic stirring. The autoclave was heated by a 200-watt band heater equipped with a proportional temperature controller. Internal temperature was monitored with a platinum resistance thermometer of ±0.1° accuracy.
The autoclave was connected to a gas manifold for initial pressurization with reactant gases. An external reservoir of 0.5 liter capacity containing CO:H 2 in 1:1 molar proportion was connected to the autoclave by means of a Research Control™ motor valve. In order to measure pressure in the reaction chamber the autoclave was also equipped with a 100-135 psi pressure transmitter. During hydroformylation the autoclave was maintained at 120 psig via the external reservoir/motor valve/pressure transmitter. Reaction rate was calculated from the rate of pressure drop in the external reservoir.
EXAMPLE 1
Control-ATBE containing 0.17 percent peroxide.
20 ml of catalyst solution, containing 200 ppm rhodium as RhH(CO)(Ph 3 P) 3 and 10% triphenylphosphine, in n-butyraldehyde trimer solvent, was charged to a preheated reactor at 70° C. After the temperature of the catalyst solution equilibrated to 70° C. 5.7 grams of ATBE containing 0.17 weight % hydroperoxide was injected into the reactor followed by 40 p.s.i. H 2 , 20 p.s.i. CO and nitrogen to a total of 120 p.s.i. The autoclave was then opened to the motor valve-reservoir assembly. The hydroformylation reaction uses CO and H 2 in 1:1 molar proportions. Carbon monoxide and hydrogen were fed in at 1:1 (CO:H 2 ) molar proportions to keep the pressure constant. The reaction rates obtained for the hydroformylation of ATBE to 4-tert-butoxybutyraldehyde are summarized in Table I below, under Example 1.
EXAMPLE 2
ATBE purified with activated alumina.
A 50 cm×2 cm glass chromatographic column was packed with 50 g. activated alumina (ICN Pharmaceuticals, activity Grade I). A 200-ml commercial ATBE sample containing 0.17 weight % of hydroperoxide was passed through the column at a rate of 1.6 ml/min. A total of180 ml ATBE was eluted from the column and recovered, the other 20 ml being retained by the column. The eluted ATBE gave no inhibition in its hydroformylation reaction, when hydroformylated in accordance with the procedure of Example 1 above. Hydroformylation rates were determined as described above. The results are summarized under Example 2 in Table 1.
The qualitative analysis of the eluted ATBE and the alumina indicated that the hydroperoxides and acrolein had merely been adsorbed rather than reduced. The following procedure was employed to conduct such qualitative analysis:
Silica gel coated strips (10×3 cm) (Supplier: Eastman Kodak) were used as thin layer chromatography ("tlc") plates. A spot of ATBE (or a solution of it in CHCl 3 ) was applied on the tlc plate and the plate was developed with chloroform. After the development plate had dried, the visualization reagent* was sprayed on. In a few minutes a pink spot with Rf=0.4, i.e., the ratio of the distance moved by the hydroperoxide to the distance moved by the chloroform, developed corresponding to ATBE hydroperoxide. The intensity of the spot corresponds to the amount of hydroperoxide present.
Using the above method it was found that the ATBE eluted from the alumina column contained no hydroperoxides.
The alumina column was then washed with a total of 75 ml of methanol which was collected in three separate 25-ml portions. Qualitative analysis employing gas chromatography showed that the middle 25-ml portion of the methanol collected contained acrolein.
EXAMPLE 3
ATBE purified with Aqueous NaBH 4 .
To a 100-ml three-neck flask equipped with mechanical stirrer, reflux condenser and nitrogen inlet, were added 15 ml partially oxidized ATBE and 10 ml of 10% solution of sodium borohydride in 1N sodium hydroxide. The mixture was stirred at 23° C. for 1 hour, and then transferred to a separatory funnel under nitrogen. The organic layer was separated and washed three times with five-ml portions of degassed water. The ATBE purified in this fashion showed no catalyst inhibition in its hydroformylation reaction rate, when hydroformylated in accordance with the procedure of Example 1 above. See the results for Example 3 in Table I.
EXAMPLE 4
ATBE purified by borohydride exchange resin.
The method described in U.S. Pat. No. 4,107,099 (Example 1) was followed. Amberlyst A-26, strong base chloride form anion exchange resin (150 g), was slurry packed with water in a 50×3 cm glass column. The resin was washed successively with 2 liters of water, 1 liter ethanol and 1 liter of water. 1.8 liters of solution of sodium borohydride in sodium hydroxide (1 weight % NaBH 4 in 2.6 weight % NaOH solution) was passed through the resin over a period of 1.5 hours. The resin was then washed with 1 liter water followed by 200 ml ethanol.
A 200 ml sample of partially oxidized ATBE (0.3 weight % hydroperoxide) was passed through the column at a rate of 3 ml/min. The column effluents showed no catalyst inhibition in a hydroformylation reaction proving that acrolein was also destroyed in this treatment. See the results for Example 4 in Table I.
TABLE 1______________________________________ Example 3 Example 4 Example 2 ATBE ATBEExample 1 ATBE purified purifiedATBE purified with withcontaining with aqueous alkali borohydride0.17% activated sodium exchangeperoxide alumina borohydride resinTime.sup.a Rate.sup.b Time Rate Time Rate Time Rate______________________________________3.7 0 3.1 1.68 2.3 2.21 4.0 1.189.5 0.86 7.6 1.61 6.6 1.67 8.0 1.1813.5 1.36 10.9 1.79 10.6 1.83 11.8 1.2317.5 1.45 16.2 1.8921.1 1.47______________________________________ .sup.a time in minutes .sup.b reaction rate in g moles/L nr.
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Described herein is a process for the conversion of hydroperoxides, present in allyl-alkyl ethers to products including α,β-unsaturated aldehydes and for reducing such α,β-unsaturated aldehydes to alcohols prior to the use of the ether as a feedstock in a hydroformylation reaction to produce the corresponding ether aldehyde. The process involves contacting the ether with a metal hydride, either in aqueous solution and/or by means of an ion exchange resin. Such treatment decomposes the hydroperoxides and then reduces their α,β-unsaturated aldehyde decomposition products, thereby reducing the catalyst inhibition period present in the hydroformylation reaction which is observed when such α,β-unsaturated aldehyde impurities are present.
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TECHNICAL FIELD
The invention relates generally to a space-based observatory platform and in particular to an observatory platform in which a positioning boom disposed between the platform and its instrument payload provides thermal and dynamic isolation as well as fine pointing and momentum control.
BACKGROUND
In deploying an instrument platform for space-based observation, it is often required that the platform provide shielding from solar influence. This generally requires that a sun shield be included as part of the platform structure. The sensitive instrumentation in the instrument payload is susceptible to thermal effects and mechanical noise originating in the platform itself. In addition, it is frequently a requirement that the instrument payload be capable of a wide range of motion in order to aim the instrument as desired. Repositioning of the instrument payload can result in momentum buildup that must often be corrected at the cost of fuel or stored electric power.
Thus, a need exists for a space-based observatory platform with enhanced immunity to mechanical vibration and thermal effects, as well as fine pointing capability that does not increase the platform's susceptibility to momentum buildup.
SUMMARY
These needs and others are satisfied by the present invention, in which a positioning boom disposed between the platform and its instrument payload provides thermal and dynamic isolation as well as fine pointing and momentum control. The basic problem addressed by this invention is design of a system that isolates a sensitive payload from a warm, dynamically noisy spacecraft, which includes a sunshield. Isolation is required in terms of dynamics and heat flow, both in terms of the absolute level and its variance (thermal isolation). Secondly, it was desired that the design provide intrinsic control over momentum buildup (which is due to the separation of the center of pressure from the center of mass). The design also needs to provide a view (field of regard) to at least half the sky (in the anti-sun direction).
In one embodiment in accordance with the present invention, an improved space-based observatory platform, having an instrument payload and a sunshield, is provided. The improvement comprises a gimbaled positioning boom having a high length-to-width aspect ratio coupling the instrument payload to the observatory platform, wherein the boom has a relatively low natural frequency to minimize transmission of dynamic noise between the instrument payload and the observatory platform. In accordance with one form of the invention, the positioning boom is articulated to position the instrument payload center of gravity with respect to the sunshield center of solar pressure. The positioning boom may include a piezoelectric actuator at the point of articulation.
In one embodiment, the positioning boom further includes biaxial gimbal drives positioned proximate the instrument payload to provide rotation capability about both an elevation axis and an instrument boresight axis. The gimbal drives include piezoelectric stack-type actuators. In accordance with one aspect of the invention, the positioning boom length-to-width aspect ratio is in the range between 30 and 60.
In one form of the invention, the relatively long positioning boom positions the instrument payload at a distance from the sunshield for thermal decoupling. Furthermore, an attitude control system associated with the platform provides rotational motion control about the solar axis that extends from the sun, through the sunshield, to the instrument payload. The attitude control system may be based upon a reaction wheel arrangement. In one embodiment, the positioning boom is coupled to the observatory platform at two points of the observatory platform structure using relatively thin, highly damped bipod flexures to provide z-axis stability. The positioning boom may be layered with visco-elastic material to provide passive damping, or the positioning boom may include a plurality of piezoelectric patches disposed thereupon to provide active damping.
DESCRIPTION OF THE DRAWINGS
Features of exemplary implementations of the invention will become apparent from the description, the claims, and the accompanying drawings in which:
FIG. 1 is a perspective view of a space-based observatory platform with its instrument payload in a deployed configuration;
FIG. 2 is an elevational view of the instrument payload in a first configuration;
FIG. 3 is an elevational view of the instrument payload in a second configuration;
FIG. 4 illustrates mounting of the positioning boom to the platform;
FIG. 5 is a close-up view of the mounting detail of FIG. 4 ; and
FIG. 6 depicts pointing actuators for the instrument payload.
DETAILED DESCRIPTION
The present invention contemplates the use of a long, gimbaled, highly damped positioning boom to attach the payload to the spacecraft. The boom has a low natural frequency, which minimizes transmission of dynamic noise from the spacecraft, satisfying the first requirement. The boom can rapidly damp our vibrations induced by these disturbance sources. The boom is also a poor thermal conductor, since it is long with a small cross-section, and it moves the telescope away from the heat shield, lowering the radiative coupling between the payload and spacecraft. The reduced coupling between the sunshield and spacecraft significantly lowers the magnitude of thermal variations as the telescope's orientation is changed. In one embodiment, an active damping system is employed for the boom, with feedback control that operates at very low levels. The boom may have piezoelectric patches for active vibration damping and small pointing adjustments.
Furthermore, a gimbal at the end of the boom provides the ability to move the payload relative to the line connecting the sun and the center of solar radiation pressure, thus moving the center of mass of the entire satellite, relative to the center of pressure, in such a way as to minimize solar torques, momentum buildup, use of the reaction wheels, dynamic input, and consumption of fuel for momentum dumping. The positioning boom can also be made to offset the CG from the CP in a selected direction in order to reduce the momentum stored in the reaction wheels, eliminating the need to use propellant to dump momentum in most cases. The positioning boom is not in the launch load path and is not required to carry launch-induced stresses. Therefore, it can be made to meet all of these requirements.
In operation, one of the advantages of the present invention is that the boom can be designed to have very low frequency modes, effectively isolating the dynamic disturbances (from the spacecraft) from the instrument payload (such as a telescope). The positioning boom can also be made a “smart strut” that can be tuned in terms of its stiffness once on orbit (and bent slightly to make pointing adjustments). The decrease in the thermal input from the spacecraft and sunshield relaxes the requirements on the sunshield, and improves telescope performance.
Finally, the ability to move the center of mass of the entire satellite, relative to the center of pressure, allows for reduced reliance on the reaction wheels to counter solar torques, thus minimizing momentum buildup and reducing their dynamic input. This kind of momentum management allows for more efficient use of fuel needed to unload saturated momentum wheels. This allows for longer and more efficient missions, since thruster firings for momentum unloading are fewer and further between. Locating the telescope further away from the sunshield allows the telescope to look at more than half the sky, relaxing operational constraints and making for a higher performance mission.
Turning to FIG. 1 , a perspective view of a space-based platform is presented. One should consider that the illustrated configuration is consistent with the design strategies of the James Webb Space Telescope, or JWST, intended for deployment in 2011. The JWST will observe primarily the infrared light from faint and very distant objects. But all objects, including telescopes, also emit infrared light. To avoid swamping the very faint astronomical signals with radiation from the telescope, the telescope and its instruments must be very cold. Therefore, JWST has a large shield that blocks the light from the Sun, Earth, and Moon, which otherwise would heat up the telescope, and interfere with the observations.
In order for this concept to operate properly, JWST must be in an orbit where all three of these objects are in about the same direction. The most convenient point is the second Lagrange point (L2) of the Sun-Earth system, a semi-stable point in the gravitational potential around the Sun and Earth. Of course, these constraints also apply to instrument payloads that are not designed to collect optically-derived data. An optical payload is shown in the drawings merely for illustrative purposes.
FIG. 1 illustrates an optical payload with a bore-sight as indicated, having a primary focal point 102 within the tube structure, or tower housing, of the telescope. A secondary mirror 101 is disposed within the tower housing. The telescope has a gregorian-style off-axis paraboloid mirror 107 and a primary mirror reaction structure 108 that provides an adjustment base for fine tuning the primary mirror surface. Structurally, the instrument includes a support truss 103 and a tertiary optical component housing 104 .
In one embodiment, the positioning boom 106 includes a telescoping mechanical damper with 50% to 100% Cr damping. This may be termed a jitter isolation damper. The damping of the boom may be active or passive. A piezoelectric actuator 109 at the point of articulation of the positioning boom 106 keeps the instrument payload center of gravity (CG) lined up with the solar pressure force center, as will be described more fully below in conjunction with FIGS. 2 and 3 . As noted previously, the platform is a JWST-style system, having a JWST-type Bus/solar array/com system 112 . The entire platform may be rotated 360 degrees about the sun vector 111 , using an attitude control system that may be based upon one or more reaction wheels, for example.
FIG. 2 shows the instrument payload 201 in a first orientation with the bore-sight aimed in a first desired direction. It should be noted that the positioning boom 106 is articulated in a first direction on order to maintain the instrument payload CG in alignment with the solar pressure force center. In FIG. 3 , which shows the instrument payload in a second configuration, aiming of the bore-sight has been altered dramatically, and the positioning boom 106 is articulated in the opposite direction from the configuration shown in FIG. 2 to maintain the payload CG in its proper alignment. The positioning boom 106 , which may be highly damped in one embodiment, serves multiple purposes. It positions the instrument payload CG with respect to the sunshield solar pressure CG, it serves as a very low frequency isolator (around 0.1 Hertz) in order to structurally decouple the instrument payload from the platform, and it positions the instrument payload at a distance away from the sunshield that is sufficient for thermal decoupling.
FIGS. 4 and 5 depict the mounting arrangement utilized for the positioning boom 106 at the space platform end. The positioning boom 106 , which is long, skinny, and highly-damped in one embodiment, provides flexibility in five degrees of freedom (with the exception of z-axis translation). The boom 106 is secured in position at the platform end by thin, highly damped bipod flexures 402 that are mounted at two points of the spacecraft structure in order to maximize z-direction flexibility.
For proper performance, the boom 106 must have a relatively large length-to-width aspect ratio, although the specific value is dependent upon a number of factors. Aspect ratios in the range from about 30 to 60 have been shown to work adequately. As a general matter, the boom 106 should be from 10 to 20 meters in length, with a width from about 150 mm to about 300 mm.
The boom 106 is constructed of graphite in one embodiment, such as a GFRP graphite material. Of course, other materials, such as titanium, for example, will also perform well, although metallic implementations may be undesirable where weight is a concern. For passive damping, a graphite boom would be layered with a visco-elastic material. Of course, a passively damped system must be kept warm for proper operation. This can be accomplished by surrounding the boom with a heated sock, for example, as known in the art.
Active damping is generally accomplished by disposing a plurality of piezoelectric actuators 403 along the length of the boom 106 . Stresses along the boom 106 caused by flexing are transmitted to the proximate piezoelectric sensor, and a corresponding actuator is then used to provide a force acting on the boom in the opposite direction.
FIG. 6 is illustrative of the pointing actuators for the instrument payload. Instrument payload fine-pointing actuators 601 , with nano-radian resolution, are implemented using a tip/tilt plate (for azimuth and elevation of the instrument) using piezoelectric stacks. A bore sight axis rotation gimbal 602 yields a plus-or-minus 90 degree range of adjustment with 50 micro-radian resolution. A cable-wrap safely routes the harness across the joint, with cable wrap diameter sized according to wire count. The elevation axis gimbal 603 provides the same range of motion and resolution as the rotation gimbal 602 , with low load level hysteresis less than one nano-radian. As noted previously, the positioning boom 106 is highly damped (50% to 100% Cr) in one embodiment, and overall platform rotation about the azimuth axis 604 is provided by the platform's attitude control system (ACS). Rotation has a range of plus-or-minus 180 degrees with a 50 micro-radian resolution, and low load level hysteresis less than one nano-radian.
Although exemplary implementations of the invention have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions, and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims.
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A positioning boom disposed between a space-based observatory platform and its instrument payload provides thermal and dynamic isolation as well as fine pointing and momentum control. The inventive system isolates a sensitive payload from a warm, dynamically noisy spacecraft, which includes a sunshield. Isolation is required in terms of dynamics and heat flow, both in terms of the absolute level and its variance (thermal isolation). The present invention provides intrinsic control over momentum buildup (which is due to the separation of the center of pressure from the center of mass). The space-based platform also provides a view (field of regard) to at least half the sky (in the anti-sun direction).
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CROSS-REFERENCE TO RELATED APPLICATION
The present application claims the benefit of previously filed Provisional Patent Application, Ser. No. 61/205,969.
FIELD OF THE INVENTION
This invention addresses the need to transport high bit-rate data and voice to multiple users over wired and wireless means. More specifically a system and method for a mobile switching center to efficiently manage; assign; and reclaim the IP addresses is disclosed.
BACKGROUND OF THE INVENTION
Specialized Modulation techniques, which have now become known by their commercial designation, xMax, were designed by xG Technology, Inc., the Assignee of this application to help alleviate the problems exhibited by ultra wide band and mono pulse modulation schemes. A system and method for a mobile switching center to efficiently manage; assign; and reclaim the IP addresses is disclosed in the preferred embodiment as being used in xMax but can be implemented on any broad band wireless technologies like WiMax, WiBro, WiFi, 3GPP and HSDPA, or any other type of wired or wireless voice or data systems.
A heterogeneous MAC protocol proposed to support VoIP traffic in xMAX wireless networks has been discussed in previously filed patent applications U.S. Ser. Nos. 12/069,057; 12/070,815; 12/380,698; 12/384,546; 12/386,648; 12,387,811; 12/387,807, 12/456,758, 12/456,725, 12/460,497, 12/583,627, 12/583,644, 12/590,472, 12/590,469, 12/590,931, 12/653,021 and 12/653,007 which are incorporated by reference into this disclosure. In the heterogeneous MAC protocol described in these applications, guaranteed timeslots are assigned to forward VOIP packets, temporary timeslots are assigned to forward data packets and contention based access is used to exchange control messages. Note that this heterogeneous MAC protocol is used here as a reference protocol and similarly xMAX as a reference wireless network. The idea of a system and method for a mobile switching center to efficiently manage; assign; and reclaim the IP addresses as disclosed herein can be used in other relevant systems.
BRIEF SUMMARY OF THE INVENTION
A mechanism for decreasing the latency in an IP address assignment process for mobile systems using IP as a network layer protocol is described in A Proxy Based Approach for IP Address Assignment to Decrease Latency of Hand-offs in Mobile IP Telephony Provisional Application No. 61/192,799 by Shashidhar Gandham and Amit Shukla. The mechanism involves splitting the IP address assignment functionality into two parts, with the Base Station being responsible for assigning IP addresses to individual end user devices and the mobile switching center assigning a block of IP addresses to each Base Station. The invention mentioned above presented details about the base stations assigning IP addresses to the end user devices. In this invention disclosure a methodology for the mobile switching center to efficiently manage; assign and reclaim the IP addresses is presented. Also proposed are improvements for fault-tolerance.
DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be made to the accompanying drawings, in which:
FIG. 1 is a diagram showing a multi-sector xMAX system;
FIG. 2 is a diagram showing message flow for IP address assignment;
FIG. 3 is a diagram showing startup message flow; and,
FIG. 4 is a diagram showing address lease renewal message flow.
DETAILED DESCRIPTION OF THE INVENTION
In typical mobile VOIP systems (for example, xMAX) one Base Station (BTS) services multiple handsets. Similarly, one Mobile Switching Center (MSC) provides service to multiple Base Stations as shown in FIG. 1 . In a typical deployment scenario, multiple Base Stations will be needed to cover a citywide area. As a user moves around, the handset will have to seamlessly hand-off from one BTS to another. One of the key requirements for any mobile VOIP system is that there should be no disruption in voice traffic during handoffs to ensure that minimal voice packets are dropped.
Each MSC forms an IP subnet. If a handset moves from one Base Station to another within the service area of the same MSC, it does not need to change its IP address. However, when a handset moves from one Mobile Switching Center (MSC) to another, it must obtain a new IP Address. The latency involved in obtaining an IP address should be negligible so that the user does not notice any appreciable drop in voice quality.
A normal Dynamic Host Configuration Protocol (DHCP) exchange involves four messages; DHCPDiscover (342 bytes), DHCPOffer (342 bytes), DHCPRequest (342 bytes), and DHCPAcknowledge (342 bytes). A typical link layer Maximum Transmit Unit (MTU) in xMAX is 64 bytes, thus a minimum of 24 fragments will be transmitted over the air. At most one fragment is transmitted in a Superframe (30 ms), thus the total latency of transmitting 24 fragments is 720 ms. This contributes to additional delay that will not be acceptable, especially during a handoff scenario. Also, at the boundary of the cell (which is typically the region where handoffs take place), signal strength is weak and link quality will be degraded. This may lead to multiple retransmissions thereby causing further delay. A new mechanism for managing, assigning, and reclaiming IP addresses is proposed in this disclosure, which allows for a much faster IP assignment.
In this proxy based approach the Base Station will maintain a pool of IP addresses, and each handset that joins the network will be assigned an IP address from this pool. The Base Station periodically obtains a pool of IP addresses from the MSC. This way, each BTS will have a unique set of IP addresses. When a handset powers up, it will send a Network Join message. On receiving this message, the BTS, in addition to registering the handset, will send a reply that will include the IP address assigned to it as shown in FIG. 2 .
The MSC has to maintain the master pool of IP addresses from which each Base Station will be assigned a distinct set of IP addresses on an on-demand basis. As shown in FIG. 1 a proxy-DHCP server residing in the MSC will be entrusted with the responsibility of efficiently assigning and reclaiming the IP addresses. This invention disclosure presents the design of one such server.
The design of the proxy server is based on the following premises: The base stations are responsible for assignment of the IP addresses to handsets which are joining the network. The handset is responsible to renew the lease of IP address that is currently assigned to it. Keep-alive messages are relied on to renew the lease on the IP address. Please refer to A Keep Alive Timeslots (KATS) Based Approach to Track Registered Handsets in xMAX Networks; Shih-Chun Chang and Shashidhar R. Gandham; U.S. application Ser. No. 12/387,811 for details on keep-alive messages. The proxy server will ensure that no duplicate IP address assignments occur and will be responsible for re-claiming unused IP addresses.
Base stations always try to maintain a set of yet-to-be assigned IP addresses such that any handset joining the network can be given one. If the pool of these IP addresses is too low, then the base station will send a request to the proxy server for additional IP addresses. On assigning a particular IP address to a handset the base station will remove it from its pool. In addition to IP assignments, the base stations generate IP lease renewal and IP free messages based on the keep-alive and network leave messages received. IP addresses corresponding to several keep-alive messages can be aggregated into one single IP lease renewal request. Note that a handset sending a keep-alive message might have joined the network at a different base station. As a result the IP address would have been assigned by a different base station. On receiving a non-hand off network leave message, the base station informs the proxy that the corresponding IP address is free to be re-assigned.
Upon receiving a request for allocating IP addresses from any base station, the proxy will send a response. The response might contain a list of IP addresses. The number of IP addresses in the response might be less than the requested number. A counter value is associated with all the IP addresses in the system. A counter value of less than eight, indicates that the IP address is in use. Before assigning an IP address the corresponding counter value is set to zero. Every three minutes, equal to the keep-alive interval, the counter value is incremented by a unit. Upon receiving a lease renewal, the counter values of the respective IP addresses are reset to zero. Note that if no lease renewal is received for a particular IP address for 24 minutes then the proxy will treat the IP address as available. On receiving a free IP address message, the proxy will set the counter value of the corresponding IP address to 9.
The proxy server and the base stations communicate using UDP messages. Hence, any base station that is added to a network needs to know about the IP address of the proxy server. To eliminate the need to configure each base station with the IP address of the proxy server, an auto-discovery feature is built into the proxy server. As base stations power up, they send an UDP broadcast DiscoverDhcp message requesting the proxy server to respond. Once the server receives a discovery message from a BTS, the proxy server will respond to the BTS with a DiscoverDhcpReply message that contains the DHCP servers IP address and port number for future communications. Please refer to FIG. 3 for message flows associated with auto discovery.
Whenever the base station has less that 64 available IP addresses, it sends a DhcpGetIpAddresses message to the proxy server. In the message, the base station can specify the number of IP addresses it is requesting. At most 256 IP addresses can be requested. The proxy server might respond with 256 or less IP addresses based on the availability of IP addresses.
In addition to the requested number of IP addresses, the DhcpGetIpAddresses message contains a RequestCounter. The RequestCounter is incremented with every new request for IP addresses. The RequestCounter value is not incremented if the DhcpGetIpAddresses message has to be retransmitted. If the base station does not get a response for DhcpGetIpAddresses, it re-transmits the request. The wait time for retransmission of the message follows an exponential back-off procedure. The proxy server will note the last received RequestCounter and the last response sent to every base station. On receiving a DhcpGetIpAddresses message the proxy server checks if the RequestCounter is same as the one it last received from the base station. If it is the same, then it simply resends the response that it sent last time.
When the proxy server does not have any available IP addresses, the response to DhcpGetIpAddresses will not have any IP addresses. In such scenarios, the base station retransmits the request following binary exponential back-off procedure.
The base station is responsible for sending a DhcpRenewLease message once every 3 minutes for all the IP addresses that are yet to be assigned to the handsets. In addition, it needs to send DhcpRenewLease messages on behalf of the handsets that are currently registered with it. Note that all the handsets are sending a keep-alive message once every 3 minutes to the base station. In each super-frame, the base station may receive at most 18 (one per channel) keep-alive messages. The base stations accumulate all the keep-alive messages received in 14 super-frames and send a cumulative DhcpRenewLease message to the proxy server. Note that these messages have at most 252(14*18) IP addresses. The DhcpRenewLease message will cause the IpLeaseRenewalCount for corresponding IP address to be reset to zero.
If the base station receives a non-hand off network leave message from any handset, then it informs the proxy server that the corresponding IP address is free to be re-assigned. On receiving a DhcpFreeIP the proxy server will set the IpLeaseRenewalCount for the corresponding IP address to 9.
In this section we present typical message exchanges involved in this proxy DHCP solution. FIG. 4 illustrates the messages exchanged.
IP Address Assignment to the Base Stations: Upon powering up, the base station sends a GetIpAddresses message ( 1 ) to the proxy server. On receiving the message, the server will query the DBMS and update the fetched IP addresses by setting the IpLeaseRenewCount column to zero and save the list of IP addresses for future use ( 2 ). If the DhcpGetIpAddressesReply is not received in three seconds by the BTS ( 3 ), the BTS will send another GetIpAddresses message and wait for a reply ( 4 , 4 . 5 ). This will continue until a reply is successful. Once the BTS has IP addresses available to assign, the BTS will start broadcasting beacons over the air waiting for handset (HS) network joins to occur ( 5 , 6 , 7 ).
IP Address Assignment to Handsets: When a handset starts up, it listens for a beacon from the base stations ( 5 ). The handset might receive multiple beacons on multiple channels. Upon selecting the best possible channel to join the network, the handset sends a network join message ( 6 ). The network join message serves as an implicit request for the IP address. On receiving the network join message the base station sends an acknowledgment that includes the IP address assigned for the handset ( 7 ).
IP Address Lease Renewal: For yet to be assigned IP addresses, the base station sends a lease renewal once every 3 minutes ( 13 and 14 ). In addition, it sends lease renewals based on the keep-alive messages received from the handsets ( 8 , 9 , and 10 ). Multiple lease renewals are aggregated into single a message. Aggregation is performed over keep-alive messages received in 14 super-frames ( 11 ). The proxy server, on receiving a lease renewal, updates the LeaseCounter of corresponding IP addresses to zero ( 12 ).
Handoffs: When a handset handoffs from BTS 1 to BTS 2 , shown in FIG. 3 , then the responsibility of sending lease renewals for that particular handset rests with BTS 2 . Whenever a keep-alive message is received by BTS 2 it includes the corresponding IP address in the aggregated lease renewal message ( 17 ).
For ensuring high reliability of the proxy DHCP solution, the server module should be running on a redundant hardware configuration. In this section we describe the behavior of the IP address assignment mechanism in the event of various types of failures.
Non-Gracious Departure of Handsets: If a handset leaves a network without informing the base station that it is associated with then a message to free the particular IP address is not sent to the proxy server. As a result, the IP address is not considered for reassignment immediately. However, when the lease counter of that particular IP address exceeds 8 it will be considered for reassignment.
Crash Failure of Base Stations: A base station might crash due to a power failure, hardware component failure, or fatal errors in the software system. Whenever a base station crashes it fails to transmit the beacon at the start of every super-frame. In such scenarios, the handsets would detect that the base station is not operational in a finite amount of time. As a result, they might handoff to other base stations in the same subnet or leave the network. For handsets that are able to handoff to other base stations in the same subnet, they will be able to renew their IP address lease renewal through the keep-alive messages.
Crash Failure of Proxy Sever: If the proxy server was to fail, then any attempt from the base stations to obtain IP addresses would fail also. As a result, the base stations will send a critical alert to the xMonitor when they run out of available IP addresses.
Thus this disclosure described the design of a fault-tolerant proxy server that efficiently assigns and reclaims IP addresses in mobile switching centers that employ a proxy-DHCP solution for IP address allocation.
Since certain changes may be made in the above described system and method for a mobile switching center to efficiently manage; assign; and reclaim the IP addresses without departing from the scope of the invention herein involved, it is intended that all matter contained in the description thereof, or shown in the accompanying figures, shall be interpreted as illustrative and not in a limiting sense.
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A system and method for a mobile switching center to efficiently manage; assign; and reclaim the IP addresses is described. The procedure utilizes a mechanism that involves splitting the IP address assignment functionality into two parts, with the Base Station being responsible for assigning IP addresses to individual end user devices and the mobile switching center assigning a block of IP addresses to each Base Station and includes a methodology for the mobile switching center to efficiently manage; assign and reclaim the IP addresses.
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