description
stringlengths 2.98k
3.35M
| abstract
stringlengths 94
10.6k
| cpc
int64 0
8
|
|---|---|---|
This Application is a Section 371 National Stage Application of International Application No. PCT/GB2008/002879, filed Aug. 22, 2008 and published as WO 2009/024803 A2 on Feb. 26, 2009, the content of which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to a pitot-static device.
BACKGROUND ART
There are a range of airflow measurements for which an anemometer is the preferred solution. These include spot measurements of airflow are variable locations, such as beneath ceiling-mounted air-conditioning vents, for example. At such locations, it is aesthetically undesirable and technically unnecessary to provide a fixed or otherwise permanent airflow sensor, so a technician will take a handheld sensor to the location and hold it in the airflow of the vent
Such sensors typically comprise a rotateable vane that is mounted within a circular protective ring. The vane is typically of a metallic or plastics material, and a Hall effect or optical sensor in a handle portion extending from the ring can detect when one of the blades of the vane passes by. From this, the rotational speed of the vane can be determined, and knowledge of the aerodynamic properties of the vane will allow this to be converted to an airflow speed in the vicinity of the sensor.
Such anemometers suffer from distinct difficulties in practice. Principally, the rotating vane will have an inertia which must be overcome. This will impose a reaction time on the sensor output, and will make the sensor insensitive to small airflows. This can be reduced by reducing the mass of the vane, for example by using thin gauge sheet of a lightweight material such as aluminum, but such measures will reduce the rigidity of the vane and make it vulnerable to deformation on rough handling or shock, for example. Such deformation will change the aerodynamic properties of the vane and affect the accuracy of the sensor.
Further, the rotating vane is a moving part and hence in principle more vulnerable to wear, degradation, and the like.
Pitot-static devices are also used for measurement of airflow, as (for example) disclosed in GB-A-2,164,159. These are however bulky and have not been used for “on-the-spot” measurement via a handheld device.
A product known as the “Wilson Flow Grid” allows the measurement of airflow in a conduit such as a heating, ventilation or air-conditioning conduit or duct. It comprises a pair of square or circular grids of hollow conduits transverse to the airflow, one in front of the other. The frontmost grid has apertures in the sides of the conduits, facing into the airflow; these allow the dynamic pressure to be sampled. The rearmost grid has apertures on the two lateral sides of the conduit, at approximately 90° to the airflow, to sample the static pressure. In a rectangular grid (for a rectangular section conduit), the conduits form a gridiron pattern. In a circular grid (for a circular section conduit), the conduits are arranged as spokes from a central hub.
U.S. Pat. No. 4,453,419 shows a flow measurement device for use in a conduit, with two sets of radially-extending hollow spokes, one in front of the other. The spokes have apertures on their outer faces; thus one set has apertures facing forwards and one has apertures facing rearwardly. Each set of spokes emanates from one of two central hubs, from which dynamic and static pressure measurement are taken.
These devices are only suitable for use in fixed ducts or conduits, however. They are bulky and heavy, and not suited to portable use.
SUMMARY OF THE INVENTION
The present invention seeks to provide a handheld airflow measurement device that employs pitot-static principles instead of a rotating vane. A pitot-static device needs no moving parts and has little or no inertia.
In its first aspect, the present invention therefore provides a pitot-static device comprising a first plurality of hollow spokes and a second plurality of hollow spokes separated by an unimpeded flow path, the spokes of the first plurality being connected so as to allow fluid communication between their hollow interiors and each having at least one aperture facing in a first axial direction that is transverse to the spokes, the spokes of the second plurality being connected so as to allow fluid communication between their hollow interiors and each having at least one aperture facing in a second axial direction that is opposed to the first axial direction.
Such a device differs from the Wilson Flow Grid due to the location of the static ports. This change assists the accuracy of the device in measuring low rate airflows, and also allows the device to be made symmetrical. The latter advantage means that the device can be assembled from two identical half-mouldings and can be bi-directional; all these advantages assist in the creation of a handheld pitot-static device.
The spokes can extend radially from a central hub, with the hollow interiors of the spokes connected via one or more interior spaces within the hub. This allows the device to adopt a form and structure more closely resembling an anemometer, thereby clarifying it suitability as a direct replacement.
The second plurality of spokes can each have an aperture at the end thereof, which allows a more accurate determination of the static pressure. To maintain the symmetricality of the device and allow its manufacture as two half-mouldings, the spokes of the first plurality can also have an aperture at an end thereof, although that will need to be sealed against fluid communication at (perhaps) a later stage of manufacture. These end apertures can be additional to or as a replacement for the reverse-directed apertures of the second plurality.
The device can comprise a handle for manual support, to allow it to be carried and located as required. Alternatively, or in addition, it can comprise a socket for attaching the device to a pole or other support.
In another aspect, the present invention provides a pitot-static device comprising a first plurality of hollow spokes extending radially from a central hub and a second plurality of hollow spokes extending in a radial direction from a central hub, the spokes of the first plurality being connected so as to allow fluid communication between their hollow interiors, and at least all but one having at least one aperture facing in a first axial direction that is transverse to the radial direction, the spokes of the second plurality being connected so as to allow fluid communication between their hollow interiors, and at least all but one having at least one aperture, the device further comprising a handle for manual support. Having a handle, the device will be suited to portable uses; by combining this with a pitot-static measurement of airflow, the problems inherent in anemometer-based devices are avoided.
In this aspect, at least all but one of the spokes of the second plurality preferably has an aperture at an end portion thereof that faces in the radial direction. Likewise, for simplicity of manufacture, at least one of the spokes of the first plurality also preferably has an aperture at an end thereof which is sealed against fluid communication. The device of any of the above aspects can further comprise a ring around the central hub, the spokes extending from the hub to an inner face of the ring. Where some or all spokes have an aperture at the end thereof, the end apertures can extend through the ring.
A handle (where provided) can be conveniently attached to the ring. A conduit can usefully be provided between the central hub and the handle, to convey the pressure measurements to the handle and hence to an external measurement apparatus such as via a connector on the handle for external fluid conduits. The conduit preferably has no apertures between the central hub and the handle, as apertures on the conduit would contribute disproportionately to the pressure measurement.
The hub can be formed of a moulding integral with the spokes, covered by a suitable cap. This assists greatly in the manufacture of the device as simply as possible, and the present invention therefore also relates to such a device.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the present invention will now be described by way of example, with reference to the accompanying figures in which;
FIG. 1 shows a perspective view of a device according to the invention;
FIG. 2 shows a perspective view of the top region of a half-moulding suitable for assembling into the device of FIG. 1 ;
FIG. 3 shows a perspective view of the underside of the half-moulding of FIG. 2 ;
FIG. 4 shows a longitudinal section through the device of FIG. 1 ;
FIG. 5 shows an enlarged view of a region of FIG. 4 ;
FIG. 6 shows a plot of actual air velocity (V t ) against measured air velocity (V m ) for a range of embodiments, between 0 and 25 ms −1 ;
FIG. 7 shows a plot of actual air velocity (V t ) against measured air velocity (V m ) for a range of embodiments, between 0 and 5 ms −1 ;
FIG. 8 shows a plot of actual air velocity (V t ) against measured air velocity (V m ) for a range of embodiments, between 0 and 2 ms −1 ;
FIG. 9 shows a plot of actual air velocity (V t ) against measured air velocity (V m ) for a range of embodiments, between 0 and 1 ms −1 ;
FIG. 10 shows an alternative constructional method for the device of the present invention; and
FIG. 11 shows a further alternative constructional method for the device of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
FIG. 1 shows a device according to the present invention. An airflow meter 10 comprises a handle 12 attached to an outer surface of a ring 14 . The ring 14 comprises a short cylindrical section that serves to define a flow passage. The device measures the rate of flow of a fluid through that passage.
A central hub 16 is located substantially concentrically within the ring 14 and has two internal spaces, as will be described later. The central hub 16 is generally streamlined so as to cause relatively little disturbance to an airflow through the ring 14 . Each internal space is connected to a respective conduit 18 , 20 that extends from the central hub 16 to the interior of the handle 12 . Within the handle 12 , connectors are provided to allow the conduits 18 , 20 to be linked to flexible tubes leading to an external micromanometer for measuring pressure differences between the two conduits 18 , 20 . The micromanometer may be as described in GB-A-2298281, for example.
Two arrays of spokes are located between the central hub 16 and the ring 14 , one in front of the other. The first array consists of five spokes 22 with hollow interiors communicating with one interior space of the hub 16 and thence conduit 18 . Together with the conduit 18 , these spokes are spaced at 60° intervals to form a symmetrical pattern. Each spoke 22 has a plurality of apertures 24 on the front face thereof, in this case three although there could be one, two or more than three apertures. As they are located on the front face of the spoke 22 , they face into an airflow that is flowing through the ring 14 and therefore sense a dynamic pressure created by that airflow.
The conduit 18 does not have any apertures. If an aperture on the conduit 18 did not face into the airflow then it would affect the dynamic pressure reading. If it did face into the airflow in the same orientation as the apertures 24 of the spokes 22 , then it would sense the same dynamic pressure but the apertures of the conduit 18 would be in a different topological location relative to the micromanometer and the hub 16 as compared to the apertures 24 , and this might distort the measured pressure. Accordingly, we prefer (as shown in FIG. 1 ) to provide a sealed conduit 18 .
The second array of five spokes 26 are each located behind a spoke of the first array, and together with the conduit 20 are again spaced at 60° intervals. Each has three apertures (not visible in FIG. 1 ) that are diametrically opposed to the apertures 24 of the first array of spokes 22 , i.e. point in an opposite direction. Again, there need not be three apertures although we find that this number is convenient. These apertures point in the lee direction of an airflow through the ring 14 and therefore sense a static pressure. That static pressure is fed through the conduit 20 and thence to the micromanometer. As a result, the micromanometer has access to a static and a dynamic pressure measurement and the airflow speed can be calculated using known techniques.
In addition to the apertures in the lee of the airflow, the spokes 26 of the second array each have an aperture 28 at an end thereof that extends through the ring 14 to the circumferential exterior face thereof. These allow a more balanced measurement of the static pressure.
The conduit 20 has no apertures, for the same reasons as set out above in relation to the conduit 18 .
Although five spokes in each array are shown, each forming (with its respective conduit) a symmetrical pattern with a rotational symmetry of 6, this number can be varied and strict symmetricality could be departed from. A balanced pattern with few spokes is likely to cause the least disturbance to the airflow being measured, although more spokes will provide for a greater number of sampling points in the airflow. We therefore prefer a symmetrical 6-spoke arrangement, but other arrangements are also likely to yield good results.
The spokes of the two arrays are shown as being aligned in the direction of the airflow, so that for each spoke of the first array there is a spoke of the second array directly behind it. Again, we prefer this arrangement as it is likely to cause the least disturbance to airflow, but other arrangements could be adopted, including arrangements in which the spokes of different arrays are not aligned and arrangements in which the arrays have different numbers of spokes.
FIG. 2 shows a half-moulding 30 from which the device 10 of FIG. 1 can be produced. It is referred to as a half-moulding since the moulded item 30 provides approximately one half of the total device 10 ; two identical such half-mouldings 30 are assembled (together with other small parts) to form the device 10 .
Thus, the half-moulding 30 of FIG. 2 is (by way of example) destined to form the front half of a device 10 and thus has a half handle 32 , a half ring 34 , a half hub 36 concentrically within the half ring 34 , a conduit 18 leading from the half hub 36 to the half handle 32 , and five spokes spaced at 60° intervals starting at the conduit 18 and leading from the half hub 36 to the half ring 34 . Each spoke 22 has three apertures 24 facing axially forward with respect to the central axis of symmetry of the half ring 34 .
An end aperture is also provided for each spoke 22 , extending from the hollow interior of the spoke 22 to the exterior face of the half ring 34 . This provision allows the half-moulding 30 to act as a rear half of a device 10 (in which case the spokes will be spokes 26 sensing static pressure). As part of the assembly process, these apertures 38 are sealed, for example by application of an adhesive tape to cover the aperture 38 or by insertion of a suitable plug into the end of the aperture 38 . As a alternative, 50% of the half mouldings 30 could be prepared without apertures 38 , but this would break the symmetry between the two items and hence double the tooling cost, increase inventory costs, etc.
A clip 40 extends from the half ring 34 towards the space that will be occupied by the companion half moulding that will make up the remainder of the device 10 . This is at a location on the half ring 34 offset from the conduit 18 by slightly more than 120° (to avoid the apertures 38 ), and is balanced by a recess 42 shown in FIG. 3 at the mirror-image location on the half-ring 34 . Thus, when the half-moulding 30 and its companion are mated, the clip 40 of the half-ring 30 mates with the recess of the companion, and the clip of the companion mates with the recess 42 . Clip-locking elements in the clip 40 and the recess 42 of conventional design then ensure a snap fit between the half-moulding 30 and its companion.
FIG. 3 shows the reverse side of the half-hub 36 . It can be seen that this is a hemispherical shape (to provide the necessary streamlining) with the spokes 22 and conduit 18 communicating with the interior of the hemisphere. As a result, the pressures sensed by the spokes 22 can be averaged and sampled by the conduit 18 . During assembly, a cap is fitted to the half-hub 36 to close the hemisphere and provide a sealed interior space. An O-ring can be provided between the moulded half-hub 36 and the moulded cap to ensure a sufficient seal is obtained.
The conduit 18 leads into a hollow space within the half-handle 32 , and projects a short distance thereinto. This short projection acts as a connector for receiving a flexible hose that can convey the sensed pressure to a micromanometer. A circular hole 44 is provided in the half-handle opposite the conduit 18 to allow such a hose to leave the handle. Other forms of connector could be provided as desired or as required.
Pillars 46 , 48 are provided within the half-handle 32 to mate with identical pillars on the companion half-moulding in a known fashion and secure the two parts together.
FIG. 4 shows a cross-section through the device 10 . Air or another fluid to be measured flows through the ring 14 in the direction of arrow 50 and impinges on the apertures 24 of the spoke 22 to establish a dynamic pressure within the hollow interior of the spoke 22 . This is conveyed to an interior space of the hub 16 defined by the half-hub hemisphere 36 and the cap 52 . This is averaged with the dynamic pressures from the other spokes not visible in FIG. 4 and fed via the conduit 18 into a dynamic hose 54 connected to an end 56 of conduit 18 . The dynamic hose 54 departs the handle 12 via the hole 44 to a micromanometer (not shown).
Likewise, the apertures 58 on the spoke 26 , being directed in an opposite direction to the apertures 24 , are able to sense a static pressure. The end apertures 28 are also able to sense a static pressure outside the ring 14 . The static pressures sensed by the apertures 58 and end apertures 24 of the five spokes 26 are fed to a further interior space within the hub 16 , this time defined by the rearmost half-hub 36 ′ sealed by a further cap 52 and O-ring, where they are averaged and conveyed along the conduit 20 to a static hose 60 connected to an end 62 of the conduit 20 . This likewise exits the handle 12 via a further hole 44 ′.
As can be seen in FIG. 4 , there is an unimpeded flow path past the two sets of spokes. In this example, there is an empty space between the two sets of spokes and therefore air (or the fluid concerned) can flow freely past the first set of spokes and then past the second. It is not strictly necessary for there to be a complete empty space; some support structures of other bracing could be provided between the two sets of spokes and if this did not extend beyond the cross-sections of the spokes in the direction of flow then this would not impede the fluid flow. However, this can be contrasted with the arrangement shown in, for example, U.S. Pat. No. 4,453,419 in which there is a transverse plate between the two sets of spokes which causes fluid flowing past the first set to divert outwardly, thereby affecting the flow pattern.
FIG. 4 also shows a seal 62 in the form of an adhesive layer over the apertures 38 at the ends of the spokes 22 . This adhesive layer can be in a number of short sections over each aperture 38 , or it can be a band around the relevant half of the ring 14 .
FIG. 5 shows an enlarged portion of the half-hub 36 , in section. Spokes 22 lead into the half-hub 36 and their hollow interiors 64 communicate with the interior of the half-hub 36 via openings 66 . A rear planar face of the half-hub 36 is initially open, but subsequently closed during assembly by way of a cap that seats opposite a shoulder 68 against which an O-ring can be compressed to provide a seal.
FIGS. 6 to 9 show graphs of the response of such a device, comparing various alternative embodiments. Data points are denoted as follows:
♦ a conventional vane anemometer X an embodiment according to FIGS. 1 to 5 * an embodiment according to FIGS. 1 to 5 but without the apertures 58 ● an embodiment according to FIGS. 1 to 5 but without the apertures 28
FIG. 6 shows the response at airflows between 0 and 25 ms −1 . Generally, all four show the same response at higher airflows. The absence of apertures 28 appears to give a proportionately slightly higher reading, but this could be corrected by suitable calibration.
FIG. 7 shows the response at airflow speeds up to 5 ms −1 , and shows a generally linear response for all four embodiments in the region above 1 ms −1 . That linear response can be corrected as required through calibration.
FIGS. 8 and 9 show the response at very low airspeeds of 1 ms −1 or less, and highlight a departure from linearity for the embodiment without the apertures 58 comparable, albeit opposite, to a departure from linearity of the conventional anemometer. It would seem that at low air speeds, the rotational inertia of the anemometer vane reduces the measured airflow as compared to the actual airflow. This difficulty is of course not faced by a pitot-static device.
It should be borne in mind that the graphs of FIGS. 6 to 9 show a “best case” for the conventional anemometer. As the anemometer ages and is handled, the vanes and the rotating axle will inevitably degrade, creating additional resistance to rotation and uncertainties in the device calibration. No corresponding problems are applicable to a pitot-static device as described.
FIGS. 10 and 11 show alternative constructional methods for the hub region of the device. In FIG. 10 , a single hub cap 100 sits between the two half-hubs 36 , 36 ′. A pair of O-rings 102 , 102 ′ are provided around a corresponding pair of snap-fit joins 104 , 104 ′ which allow the cap 100 to fit to and seal with each of the two half-hubs 36 , 36 ′. Assembly can be by fitting the cap to one half-hub 36 ′ first, then pressing the second half-hub 36 into place, or otherwise.
An internal dividing wall (not visible) within the cap 100 prevents flow between the two half-hubs and thus allows the pressures to be sensed independently. The pressure measurements can be obtained from the outer ends of the spokes 22 , or they can be extracted from the half-hubs. FIG. 10 shows a single port 106 which leads into the cap 100 above the dividing wall (as illustrated).
FIG. 11 shows an alternative hub cap 110 , partially cut away to show the internal dividing wall 112 . As can be seen, this is stepped so that in part of the hub it is closer to the half-hub 36 (not shown in FIG. 11 , for clarity) and in another part it is closer to the half-hub 36 ′. This allows for two pressure ports 114 , 166 , spaced circumferentially around the cap 110 and thus communicating with different sides of the dividing wall 112 . A flexible hose 118 is shown; the port 114 is oriented so as to lie between two spokes 22 and thus the hose 118 can fit between them for minimal obstruction to airflow. A half-aperture 120 is provided in each half-section of the ring 14 to allow the hose to pass through. An optional support 122 is provided on the adjacent spoke for the corresponding hose leading to the port 116 ; this could be replicated for the hose 118 if desired.
FIG. 11 also shows threaded inserts 124 moulded (or otherwise sealingly placed) into the ends of the spokes 22 . These allow for the connection of pressure sensing hoses (as required) or for the insertion of blanking plates where required.
The above embodiments are provided with a handle 12 for ease of use and positioning. As an alternative, or in addition, a socket such as a threaded insert could be provided on the device. Suitable locations include in one half-hub 36 (or both if symmetricality is required) or in the handle 12 itself. These could allow for the device to be mounted on a pole (or the like) to permit readings to be taken from difficult-to-reach locations.
Accordingly, the present invention provides a device that is lightweight, easily portable, and thus able to act as a direct like-for like replacement of a vane anemometer. At the same time, it provides an ab initio improvement in accuracy over an anemometer at low airflow rates and is more robust in long-term use with no moving parts and no fragile parts exposed to handling damage.
The device of the present invention is also more robust, in that it can be cleaned by simply directing a jet of high pressure air or other gas through the conduits 18 , 20 . This will entrain any accumulated dust or grit and expel it via the apertures 24 , 28 . Dust or grit that enters the bearings of a vane anemometer is difficult or impossible to remove and will necessitate replacement of the mechanism.
It will of course be understood that many variations may be made to the above-described embodiment without departing from the scope of the present invention. For example, the device could be incorporated into a larger apparatus for testing purposes or to remain there permanently for monitoring purposes. Other layouts of the spokes could be adopted, with (for example) different numbers of spokes or different dispositions such as parallel or grid layouts.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
|
A pitot-static device, comprising first and second pluralities of hollow spokes extending in a radial direction from a central hub, the hollow interiors of the spokes of the first plurality being connected so as to allow fluid communication therebetween, and at least all but one of the spokes of the first plurality having at least one aperture facing in a first axial direction that is transverse to the radial direction, and the hollow interiors of the spokes of the second plurality being connected so as to allow fluid communication therebetween, and at least one of the spokes of the second plurality having an aperture at an end portion thereof that faces in the radial direction.
| 6
|
BACKGROUND OF THE INVENTION
The invention relates to an air flow direction adjusting apparatus of a single unit air-conditioner.
In most cases, the conventional air flow direction adjusting apparatus of an air conditioner comprises a plurality of vertical air flow direction plates mounted at one end of an outlet vent which automatically directs the air flow direction to the right side or the left side of the outlet vent. Further, at the rear of the vertical air flow direction plates a plurality of horizontal air flow direction plates are mounted for the manual adjustment of the air flow direction towards the upper side or the lower side of the outlet vent.
However, in the above conventional apparatus, if a single motor is employed, the air flow is directed to only the right side or to the left side depending on the setting of the automatic air flow directional adjustment. In the event that an automatic succession of adjustments of the air flow direction toward the upper, lower, right and left side is required, the above apparatus has the problem that more than one motor is required. Further, the range of air flow adjustments of the discharged air is limited to four directions; the upper, lower, right, and left side. Thus, the air flow is repeatedly directed to one limited place. That creates another problem in that it requires a long time to reach the desired level of air conditioning. Excessive electric power consumption is necessitated, and the efficiency of the air conditioning is decreased.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of the prior art.
One object of the invention is to provide an air flow direction adjusting apparatus which achieves the maximum efficiency of the air flow so that the various directions of the air flow are repeatedly changed and then returned to the starting point, i.e. a predetermined point, in order to achieve an even distribution of the air.
Another object of the invention is to provide an air flow direction adjusting apparatus which can adjust the air flow in a full circular range direction by a single adjusting apparatus.
According to an aspect of the present invention, the air flow direction adjusting apparatus of the present invention includes an air outlet vent having a plurality of slanted air flow direction plates for directing the air flow, a support means provided adjacent to the rear surface of the outlet vent for facilitating the rotational movement and the forward or backward movement of the outlet vent, and a clockwise rotational power transmission means for driving the outlet vent in a continuous clockwise or counter clockwise direction.
Further, the outlet vent comprises a rim that houses the air flow direction plate. The rim provides first and second coaxial driven members which have different diameters.
Further, the power transmission means comprises a first and a second driving member which rotate in the same direction, and an intermediate power transmitter which engages with either the first driven member or the second driven member and the first driving member or the second driving member for rotating the rim in the opposite rotational direction of the power driving member.
Further, the first and the second power driving members on the same driving shaft provide, respectively, the first driving member drives the vent when the second driving member does not drive the vent, and the second driving member drives the vent when the first driving member does not drive the vent.
Furthermore, the intermediate power transmitter comprises a pinion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an air conditioner having the air flow direction adjusting apparatus of the present invention,
FIG. 2 is a schematic perspective view of the air flow direction adjusting apparatus,
FIG. 3 is a partial longitudinal sectional view of an air conditioner having the air flow direction adjusting apparatus,
FIG. 4 is a front elevational view of the air flow direction adjusting apparatus in a clockwise rotation, and
FIG. 5 is a front elevational view of the air flow direction adjusting apparatus in a counterclockwise rotation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, a single unit air conditioner comprises a body 1 housing an indoor heat exchanger and an outdoor heat exchanger which are not shown. In the front of the indoor heat exchanger a front cover 2 is provided which is constructed of an inlet vent 3 and an outlet vent 41 which constitute an air flow direction adjusting apparatus of the present invention. The size of the inlet vent 3 is formed to be approximately the same as that of the indoor heat exchanger. Adjacent to the inner rear surface of the indoor heat exchanger, a fan (not shown) is installed. The fan draws indoor air through the inlet vent 3 and discharges the heat exchanged air through the outlet vent 41 toward the area to be air-conditioned.
In FIGS. 2 and 3, the air flow direction adjusting apparatus 4 comprises the outlet vent 41 provided at the inner rear surface of the front cover 2 which can rotate in a full 360 degree circle, a support means 42 provided adjacent to the inner rear surface of the outlet vent 41 for accommodating forward and backward movements of the outlet vent 41 as well as the rotation thereof, and a power transmission means 43 for rotating the outlet vent 41 in either a clockwise or a counterclockwise direction, or alternatively, within a predetermined arc degree.
The outlet vent 41 provides a circular body 41A comprising a first driven gear 412 and a second driven gear 413 which are coaxial with the rim. The diameter of the first driven gear 412 is smaller than that of the second driven gear 413. Along the front of the circumference of the first driven gear 412 a circular groove 411 is provided which is engaged slidingly with a circular projecting part 21. The projecting part 21 is located at the edge of the opening 2A which is formed at the front cover 2. The projecting part 21 serves as a guide track to enable the outlet vent 41 to rotate and also to freely move forward and backward. At the center portion of the rim 41A, a plurality of slanted air flow directional vanes or plates 414 are located and positioned in one direction. Across the middle front edge of each directional plate 414 a knob 415 is attached for adjusting the air flow direction. A rotation rod 416 is attached to the rear surface of the outlet vent 41 along the central axis thereof. Along the outer circumference of the first driven gear 412 and that of the second driven gear 413 cogs (gear tooth) for more effective power transmission are provided.
The support means 42 is provided with a support cap 421 and a support rod 422 formed integrally with the body of the support cap 421. The support cap 421 has a hollow body with one end opened, in which the rotation rod 416 of the outlet vent 41 is inserted in a coaxial manner. In the hollow body of the support cap 421, a spring 423 is positioned so as to continuously push the rotation rod 416 forward toward the front cover 2. The support rod 422 is mounted detachably on the horizontal bracket 11.
The power transmission means 43 has a driving motor 431 which is mounted detachably on a vertical wall 11A which extends at an angle from a bracket 11. A rotation shaft 431A of the motor 431 extends forward, on which the hub 435 is located. Along the outer surface of the hub 435 two driving gears are formed to comprise a first fan shaped gear 433 and a second fan shaped gear 434, located a predetermined distance from each other. The second gear 434 directly engages with the second driven gear 413 while the first gear 433 indirectly engages with the first driven gear 412. The means for employing the indirect engagement is a pinion 432, which is mounted on the lower rear face of the front cover 2 by shaft 432A. The arc of the first driving gear 433 is located in the opposite direction of the arc of the second driving gear 434 as shown in FIG. 2, i.e., the arcs of the gears 433, 434 are offset by 180 degrees relative to each other. The first driving gear 433 comes into contact with the first driven body 412 while the second driving gear 434 is not in contact with the second driven gear 413, and vice versa.
According to the above structure, the air flow direction in respect to the air flow direction plate 414 of the outlet vent 41 is achieved because the outlet vent 41 can be adjusted toward the place the air is desired. In FIG. 3, the knob 415 is pushed as shown in a dotted line and the rotation shaft 416 compresses the spring 415 in the support cap 421, and thus the first driven gear 412 disengages from the pinion 432. In this condition, the user can rotate the outlet vent 41 to an any desired position and the air flow direction can thus be adjusted so as to direct the air where it is needed. After the air flow direction is determined, the outlet vent 41 is repositioned due to the force of the spring 423 such that the first driven gear 412 engages with the pinion 432.
When the first driving gear 433 engages with the first driven gear 412 via the pinion 432, and as motor 431 operates, the rotation shaft 431A rotates in a clockwise direction as shown in FIG. 4. The first driven gear 412 moves in a clockwise direction and the outlet vent also rotates in a clockwise direction within a contacting range of the first driving gear 433. After the first driving gear 433 and the pinion 432 become disengaged, the second driving gear 434 starts to engage with the second driven gear 413 of the outlet vent 41 as shown in FIG. 5. As the rotation shaft 431A rotates in a clockwise direction such that the second driving gear 434 moves in the same direction, the second driven gear 413 moves in a counterclockwise direction. After the second driving gear 434 and the second driven gear 413 become disengaged, the first driving gear 433 starts to reengage with the first driven gear 433 via the pinion 432 as shown in FIG. 4.
As the clockwise and counterclockwise direction of the outlet vent is repeatedly performed as described above, the body 41 oscillates back and forth about the axis of the rod 416 and the heat-exchanged air is directed to the place as determined by the user. The present invention thereby saves energy due to the minimum time required of the air conditioning operation, and also due to the greater efficiency of the air condition operations.
The present invention is not restricted to the above embodiment, but the present invention can also be such that the pinion is located between the second driving gear and the second driven gear.
|
An air conditioner has a flow directing vent comprised of slanted vanes. The vent is driven by a drive mechanism which oscillates the vent about an axis. The drive mechanism includes a motor driven shaft which rotates continuously in one direction, and a mechanism for converting such continuous rotation into oscillation of the vent. The drive connection between the vent and drive mechanism can be manually disconnected by axial displacement of the vent, to enable the rotational position of the vent to be adjusted relative to the drive mechanism.
| 5
|
PRIORITY CLAIM
[0001] The present application is a divisional application of U.S. patent application Ser. No. 13/319,651 filed Jan. 12, 2012, which is a National Stage of International Application No. PCT/EP2010/056404, filed on May 11, 2010, which claims priority to European Patent Application No. 09159925.8, filed on May 11, 2009 and European Patent Application No. 09159929.0, filed on May 11, 2009, the entire contents of which are being incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to the field of infant cereals. In particular, the present invention relates to the field of infant cereals that can be used to strengthen the immune system of the infant and/or that can be used to treat or prevent inflammatory disorders. For example these benefits can be provided by probiotic micro-organisms. An embodiment of the present invention relates to an infant cereal comprising non-replicating probiotic-micro-organisms, for example bioactive heat treated probiotic micro-organisms.
[0003] Newborn infants are usually fed by breastfeeding or by liquid infant feeding formulas, which resemble the content of the milk of the mother as closely as possible. Breastfeeding and/or infant formula administration will typically continue during the first year of the infants life.
[0004] However, typically at the age of 4-6 months infants develop an interest and a readiness for other foods. Signs for this are that an infant starts to be able to sit and control head movements. It will be able to move food from the front of the mouth to the back, so that the tongue coordination will allow the infant to swallow from a spoon.
[0005] The introduction of solid foods is important for the infant to build a positive relationship with food. This is the first step to a growing, happy baby, and to developing lifelong healthy eating habits.
[0006] At this stage it is recommended that an infant begins consuming infant cereals.
[0007] Infant cereals will help the infant to experience taste, texture, and nutrition. However the infants digestive tract is still developing and will have to deal with a new challenge: solid food.
[0008] Probiotics as part of gut flora help the stomach tolerate foods much easier and can also boost the immune system, for example. A new innovative product in this respect is, for example, Nestlé Baby Cereal comprising Bifidobacterium lactis cultures. These cultures maintain a healthy digestive tract flora and help support healthy growth and development.
[0009] Generally, probiotics are considered safe for infants. However under special circumstances it might be advisable not to use probiotics for infants without the consent of a doctor, for example if the infant is suffering from a compromised immune system.
[0010] There is hence a need in the art for an infant cereal that offers the benefits probiotics can provide, and that can be consumed without any concern also by infants with a compromised immune system.
SUMMARY
[0011] The present inventors have addressed this need.
[0012] It was consequently the objective of the present invention to provide an infant cereal that is easy to digest for infants, allows to experience taste, texture and nutrition and offers the probiotic benefits, while being simple to produce in industrial scale and ideally will not lose activity with longer shelf life or increased temperatures.
[0013] The present inventors were surprised to see that they could achieve this objective by the subject matter of the independent claim. The dependant claims further develop the idea of the present invention.
[0014] The present inventors provide an infant cereal comprising non-replicating probiotic micro-organisms.
[0015] The inventors were surprised to see that, e.g., in terms of an immune boosting effect and/or in terms of an anti-inflammatory effect non-replicating probiotic microorganisms may even be more effective than replicating probiotic microorganisms.
[0016] This is surprising since probiotics are often defined as “live micro-organisms that when administered in adequate amounts confer health benefits to the host” (FAO/WHO Guidelines). The vast majority of published literature deals with live probiotics. In addition, several studies investigated the health benefits delivered by non-replicating bacteria and most of them indicated that inactivation of probiotics, e.g. by heat treatment, leads to a loss of their purported health benefit (Rachmilewitz, D., et al., 2004, Gastroenterology 126:520-528; Castagliuolo, et al., 2005, FEMS Immunol. Med. Microbiol. 43:197-204; Gill, H. S. and K. J. Rutherfurd, 2001, Br. J. Nutr. 86:285-289; Kaila, M., et al., 1995, Arch. Dis. Child 72:51-53.). Some studies showed that killed probiotics may retain some health effects (Rachmilewitz, D., et al., 2004, Gastroenterology 126:520-528; Gill, H. S. and K. J. Rutherfurd, 2001, Br. J. Nutr. 86:285-289), but clearly, living probiotics were regarded in the art so far as more performing.
[0017] Consequently, the inventors now provide an infant cereal comprising non-replicating probiotic micro-organisms. These non-replicating probiotic micro-organisms are still bioactive.
[0018] One embodiment of the present invention is an infant cereal comprising at least 0.48 g/100 kJ of a protein source, at most 1.1 g/100 kJ of a lipid source, a carbohydrate source and non-replicating probiotic micro-organisms.
[0019] Infant cereals are known in the art. Infant cereals are compositions containing cereals to be administered to infants. They are usually to be administered using a spoon, and may be offered as dry cereal for infants, for example. Also ready to serve infant cereals are within the scope of the present invention. The codex alimentarius offers guidance on what ingredients an infant cereal should contain.
[0020] An “infant” means a person not more than 12 months of age.
[0021] Typically, the caloric density as well as the amounts and kinds of proteins, carbohydrates and lipids present in the infant cereal should be carefully adjusted to the needs of the infant and are dependent on the infants stage of development and age.
[0022] It is well known that the requirements for nutrition of an infant changes with the development and age of the infant, and the composition of the infant cereal ideally reflects this change.
[0023] Hence, an infant cereal according to the present invention to be to be administered to infants at the age of 4-6 months may have an energy density of 220-240 kJ/15 g, 0.8-1.2 g/15 g of a protein source, 0.1-0.3 g of a fat source and 12.3-12.7 g/15 g of a carbohydrate source. Such an infant cereal may contain, for example, Rice flour, Maize Maltodextrin, Vitamin C, and Iron.
[0024] An infant cereal according to the present invention to be to be administered to infants at the age of 6-12 months may have an energy density of 220-240 kJ/15 g, 1.5-1.9 g/15 g of a protein source, 0.2-0.4 g of a fat source and 11.1-11.5 g/15 g of a carbohydrate source. Such an infant cereal may contain, for example, Wheat flour, Semolina from wheat, Iron, Vitamin C, Niacin, Vitamin B6, Thiamin, and Maize Maltodextrin.
[0025] Infant cereals may be prepared from one or more milled cereals, which may constitute at least 25 weight-% of the final mixture on a dry weight basis.
[0026] The infant cereals of the present invention are preferably prepared from a single grain—like rice cereal or wheat cereal—because single grain compositions are less likely to cause an allergic reactions.
[0027] The infant cereals of the present invention may further contain prebiotics. Prebiotics may support the growth of probiotics before they are rendered non-replicating. “Prebiotic” means non-digestible food substances that promote the growth of health beneficial micro-organisms and/or probiotics in the intestines. They are not broken down in the stomach and/or upper intestine or absorbed in the GI tract of the person ingesting them, but they are fermented by the gastrointestinal microbiota and/or by probiotics. Prebiotics are for example defined by Glenn R. Gibson and Marcel B. Roberfroid, Dietary Modulation of the Human Colonic Microbiota: Introducing the Concept of Prebiotics, J. Nutr. 1995 125: 1401-1412.
[0028] The prebiotics that may be used in accordance with the present invention are not particularly limited and include all food substances that promote the growth of probiotics or health beneficial micro-organisms in the intestines. Preferably, they may be selected from the group consisting of oligosaccharides, optionally containing fructose, galactose, mannose; dietary fibers, in particular soluble fibers, soy fibers; inulin; or mixtures thereof. Preferred prebiotics are fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), isomalto-oligosaccharides (IMO), xylo-oligosaccharides (XOS), arabino-xylo oligosaccharides (AXOS), mannan-oligosaccharides (MOS), oligosaccharides of soy, glycosylsucrose (GS), lactosucrose (LS), lactulose (LA), palatinose-oligosaccharides (PAO), malto-oligosaccharides, gums and/or hydrolysates thereof, pectins and/or hydrolysates thereof. For example, infant cereals may contain oligofructose, inulin or a combination thereof.
[0029] Typically, infants cereals are to be mixed with water before consumption. For example 15 g of an infant cereal of the present invention may be to be mixed with 90 mL of water.
[0030] The infant cereal according to the present invention may comprise non replicating probiotic micro-organisms in any effective amount, for example in an amount corresponding to about 10 6 to 10 12 cfu/g dry weight.
[0031] “Non-replicating” probiotic micro-organisms include probiotic bacteria which have been heat treated. This includes micro-organisms that are inactivated, dead, non-viable and/or present as fragments such as DNA, metabolites, cytoplasmic compounds, and/or cell wall materials.
[0032] “Non-replicating” means that no viable cells and/or colony forming units can be detected by classical plating methods. Such classical plating methods are summarized in the microbiology book: James Monroe Jay, Martin J. Loessner, David A. Golden. 2005. Modern food microbiology. 7th edition, Springer Science, New York, N.Y. 790 p. Typically, the absence of viable cells can be shown as follows: no visible colony on agar plates or no increasing turbidity in liquid growth medium after inoculation with different concentrations of bacterial preparations (non replicating′ samples) and incubation under appropriate conditions (aerobic and/or anaerobic atmosphere for at least 24 h).
[0033] Probiotics are defined for the purpose of the present invention as “Microbial cell preparations or components of microbial cells with a beneficial effect on the health or well-being of the host.” (Salminen S, Ouwehand A. Benno Y. et al “Probiotics: how should they be defined” Trends Food Sci. Technol. 1999:10 107-10).
[0034] The possibility to use non-replicating probiotic micro-organisms offers several advantages. In severely immuno-compromised infants, the use of live probiotics may be limited in exceptional cases due to a potential risk to develop bacteremia. Non-replicating probiotics may be used without any problem.
[0035] Additionally, the provision of non-replicating probiotic micro-organisms allows the hot reconstitution while retaining health benefit for the infant.
[0036] The compositions of the present invention comprise non-replicating probiotic micro-organisms in an amount sufficient to at least partially produce a health benefit. An amount adequate to accomplish this is defined as “a therapeutically effective dose”. Amounts effective for this purpose will depend on a number of factors known to those of skill in the art such as the weight and general health state of the infant, and on the effect of the food matrix.
[0037] In prophylactic applications, compositions according to the invention are administered to a consumer susceptible to or otherwise at risk of a disorder in an amount that is sufficient to at least partially reduce the risk of developing that disorder. Such an amount is defined to be “a prophylactic effective dose”. Again, the precise amounts depend on a number of factors such as the infant's state of health and weight, and on the effect of the food matrix.
[0038] Those skilled in the art will be able to adjust the therapeutically effective dose and/or the prophylactic effective dose appropriately.
[0039] In general the composition of the present invention contains non-replicating probiotic micro-organisms in a therapeutically effective dose and/or in a prophylactic effective dose.
[0040] Typically, the therapeutically effective dose and/or the prophylactic effective dose is in the range of about 0,005 mg-1000 mg non-replicating, probiotic micro-organisms per daily dose.
[0041] In terms of numerical amounts, the “short-time high temperature” treated non-replicating micro-organisms may be present in the composition in an amount corresponding to between 10 4 and 10 12 equivalent cfu/g of the dry composition. Obviously, non-replicating micro-organisms do not form colonies, consequently, this term is to be understood as the amount of non replicating micro-organisms that is obtained from 10 4 and 10 12 cfu/g replicating bacteria. This includes micro-organisms that are inactivated, non-viable or dead or present as fragments such as DNA or cell wall or cytoplasmic compounds. In other words, the quantity of micro-organisms which the composition contains is expressed in terms of the colony forming ability (cfu) of that quantity of micro-organisms as if all the micro-organisms were alive irrespective of whether they are, in fact, non replicating, such as inactivated or dead, fragmented or a mixture of any or all of these states.
[0042] Preferably the non-replicating micro-organisms are present in an amount equivalent to between 10 4 to 10 9 cfu/g of dry composition, even more preferably in an amount equivalent to between 10 5 and 10 9 cfu/g of dry composition.
[0043] The probiotics may be rendered non-replicating by any method that is known in the art.
[0044] The technologies available today to render probiotic strains non-replicating are usually heat-treatment, γ-irradiation, UV light or the use of chemical agents (formalin, paraformaldehyde).
[0045] It would be preferred to use a technique to render probiotics non-replicating that is relatively easy to apply under industrial circumstances in the food industry.
[0046] Most products on the market today that contain probiotics are heat treated during their production. It would hence be convenient, to be able to heat treat probiotics either together with the produced product or at least in a similar way, while the probiotics retain or improve their beneficial properties or even gain a new beneficial property for the consumer.
[0047] However, inactivation of probiotic micro-organisms by heat treatments is associated in the literature generally with an at least partial loss of probiotic activity.
[0048] The present inventors have now surprisingly found, that rendering probiotic micro-organisms non-replicating, e.g., by heat treatment, does not result in the loss of probiotic health benefits, but—to the contrary—may enhance existing health benefits and even generate new health benefits.
[0049] Hence, one embodiment of the present invention is an infant cereal wherein the non-replicating probiotic micro-organisms were rendered non-replicating by a heat-treatment.
[0050] Such a heat treatment may be carried out at at least 71.5° C. for at least 1 second.
[0051] Long-term heat treatments or short-term heat treatments may be used.
[0052] In industrial scales today usually short term heat treatments, such as UHT-like heat treatments are preferred. This kind of heat treatment reduces bacterial loads, and reduces the processing time, thereby reducing the spoiling of nutrients.
[0053] The inventors demonstrate for the first time that probiotics micro-organisms, heat treated at high temperatures for short times exhibit anti-inflammatory immune profiles regardless of their initial properties. In particular either a new anti-inflammatory profile is developed or an existing anti-inflammatory profile is enhanced by this heat treatment.
[0054] It is therefore now possible to generate non replicating probiotic micro-organisms with anti-inflammatory immune profiles by using specific heat treatment parameters that correspond to typical industrially applicable heat treatments, even if live counterparts are not anti-inflammatory strains.
[0055] Hence, for example, the heat treatment may be a high temperature treatment at about 71.5-150° C. for about 1-120 seconds. The high temperature treatment may be a high temperature/short time (HTST) treatment or a ultra-high temperature (UHT) treatment.
[0056] The probiotic micro-organisms may be subjected to a high temperature treatment at about 71.5-150° C. for a short term of about 1-120 seconds.
[0057] More preferred the micro-organisms may be subjected to a high temperature treatment at about 90-140° C., for example 90°-120° C., for a short term of about 1-30 seconds.
[0058] This high temperature treatment renders the micro-organisms at least in part non-replicating.
[0059] The high temperature treatment may be carried out at normal atmospheric pressure but may be also carried out under high pressure. Typical pressure ranges are form 1 to 50 bar, preferably from 1-10 bar, even more preferred from 2 to 5 bar. Obviously, it is preferred if the probiotics are heat treated in a medium that is either liquid or solid, when the heat is applied. An ideal pressure to be applied will therefore depend on the nature of the composition which the micro-organisms are provided in and on the temperature used.
[0060] The high temperature treatment may be carried out in the temperature range of about 71.5-150° C., preferably of about 90-120° C., even more preferred of about 120-140° C.
[0061] The high temperature treatment may be carried out for a short term of about 1-120 seconds, preferably, of about 1-30 seconds, even more preferred for about 5-15 seconds.
[0062] This given time frame refers to the time the probiotic micro-organisms are subjected to the given temperature. Note, that depending on the nature and amount of the composition the micro-organisms are provided in and depending on the architecture of the heating apparatus used, the time of heat application may differ.
[0063] Typically, however, the composition of the present invention and/or the micro-organisms are treated by a high temperature short time (HTST) treatment, flash pasteurization or a ultra high temperature (UHT) treatment.
[0064] A UHT treatment is Ultra-high temperature processing or a ultra-heat treatment (both abbreviated UHT) involving the at least partial sterilization of a composition by heating it for a short time, around 1-10 seconds, at a temperature exceeding 135° C. (275° F.), which is the temperature required to kill bacterial spores in milk. For example, processing milk in this way using temperatures exceeding 135° C. permits a decrease of bacterial load in the necessary holding time (to 2-5 s) enabling a continuous flow operation.
[0065] There are two main types of UHT systems: the direct and indirect systems. In the direct system, products are treated by steam injection or steam infusion, whereas in the indirect system, products are heat treated using plate heat exchanger, tubular heat exchanger or scraped surface heat exchanger. Combinations of UHT systems may be applied at any step or at multiple steps in the process of product preparation.
[0066] A HTST treatment is defined as follows (High Temperature/Short Time): Pasteurization method designed to achieve a 5-log reduction, killing 99,9999% of the number of viable micro-organisms in milk. This is considered adequate for destroying almost all yeasts, molds and common spoilage bacteria and also ensure adequate destruction of common pathogenic heat resistant organisms. In the HTST process milk is heated to 71.7° C. (161° F.) for 15-20 seconds.
[0067] Flash pasteurization is a method of heat pasteurization of perishable beverages like fruit and vegetable juices, beer and dairy products. It is done prior to filling into containers in order to kill spoilage micro-organisms, to make the products safer and extend their shelf life. The liquid moves in controlled continuous flow while subjected to temperatures of 71.5° C. (160° F.) to 74° C. (165° F.) for about 15 to 30 seconds.
[0068] For the purpose of the present invention the term “short time high temperature treatment” shall include high-temperature short time (HTST) treatments, UHT treatments, and flash pasteurization, for example.
[0069] Since such a heat treatment provides non-replicating probiotics with an improved anti-inflammatory profile, the infant cereal of the present invention may be for use in the prevention or treatment of inflammatory disorders.
[0070] The inflammatory disorders that can be treated or prevented by the composition prepared by the use of the present invention are not particularly limited. For example, they may be selected from the group consisting of acute inflammations such as sepsis; burns; and chronic inflammation, such as inflammatory bowel disease, e.g., Crohn's disease, ulcerative colitis, pouchitis; necrotizing enterocolitis; skin inflammation, such as UV or chemical-induced skin inflammation, eczema, reactive skin; irritable bowel syndrome; eye inflammation; allergy, asthma; and combinations thereof.
[0071] If long term heat treatments are used to render the probiotic micro-organisms non-replicating, such a heat treatment may be carried out in the temperature range of about 70-150° C. for about 3 minutes-2 hours, preferably in the range of 80-140° C. from 5 minutes-40 minutes.
[0072] While the prior art generally teaches that bacteria rendered non-replicating by long-term heat-treatments are usually less efficient than live cells in terms of exerting their probiotic properties, the present inventors were able to demonstrate that heat-treated probiotics are superior in stimulating the immune system compared to their live counterparts.
[0073] The present invention relates also to an infant cereal comprising probiotic micro-organisms that were rendered non-replicating by a heat treatment at at least about 70° C. for at least about 3 minutes.
[0074] The immune boosting effects of non-replicating probiotics were confirmed by in vitro immunoprofiling. The in vitro model used uses cytokine profiling from human Peripheral Blood Mononuclear Cells (PBMCs) and is well accepted in the art as standard model for tests of immunomodulating compounds (Schultz et al., 2003, Journal of Dairy Research 70, 165-173; Taylor et al., 2006, Clinical and Experimental Allergy, 36, 1227-1235; Kekkonen et al., 2008, World Journal of Gastroenterology, 14, 1192-1203)
[0075] The in vitro PBMC assay has been used by several authors/research teams for example to classify probiotics according to their immune profile, i.e. their anti- or pro-inflammatory characteristics (Kekkonen et al., 2008, World Journal of Gastroenterology, 14, 1192-1203). For example, this assay has been shown to allow prediction of an anti-inflammatory effect of probiotic candidates in mouse models of intestinal colitis (Foligne, B., et al., 2007, World J. Gastroenterol. 13:236-243). Moreover, this assay is regularly used as read-out in clinical trials and was shown to lead to results coherent with the clinical outcomes (Schultz et al., 2003, Journal of Dairy Research 70, 165-173; Taylor et al., 2006, Clinical and Experimental Allergy, 36, 1227-1235).
[0076] Allergic diseases have steadily increased over the past decades and they are currently considered as epidemics by WHO. In a general way, allergy is considered to result from an imbalance between the Th1 and Th2 responses of the immune system leading to a strong bias towards the production of Th2 mediators. Therefore, allergy can be mitigated, down-regulated or prevented by restoring an appropriate balance between the Th1 and Th2 arms of the immune system. This implies the necessity to reduce the Th2 responses or to enhance, at least transiently, the Th1 responses. The latter would be characteristic of an immune boost response, often accompanied by for example higher levels of IFNγ, TNF-α and IL-12. (Kekkonen et al., 2008, World Journal of Gastroenterology, 14, 1192-1203; Viljanen M. et al., 2005, Allergy, 60, 494-500)
[0077] The infant cereal of the present invention allows it hence to treat or prevent disorders that are related to a compromised immune defense.
[0078] Consequently, the disorders linked to a compromised immune defense that can be treated or prevented by the composition prepared by the use of the present invention are not particularly limited.
[0079] For example, they may be selected from the group consisting of infections, in particular bacterial, viral, fungal and/or parasite infections; phagocyte deficiencies; low to severe immunodepression levels such as those induced by stress or immunodepressive drugs, chemotherapy or radiotherapy; natural states of less immunocompetent immune systems such as those of the neonates; allergies; and combinations thereof.
[0080] The infant cereal described in the present invention allows it also to enhance an infant's response to vaccines, in particular to oral vaccines.
[0081] Any amount of non-replicating micro-organisms will be effective. However, it is generally preferred, if at least 90%, preferably, at least 95%, more preferably at least 98%, most preferably at least 99%, ideally at least 99.9%, most ideally all of the probiotics are non-replicating.
[0082] In one embodiment of the present invention all micro-organisms are non-replicating.
[0083] Consequently, in the infant cereal of the present invention at least 90%, preferably, at least 95%, more preferably at least 98%, most preferably at least 99%, ideally at least 99.9%, most ideally all of the probiotics are non-replicating.
[0084] All probiotic micro-organisms may be used for the purpose of the present invention.
[0085] For example, the probiotic micro-organisms may be selected from the group consisting of bifidobacteria, lactobacilli, propionibacteria, or combinations thereof, for example Bifidobacterium longum, Bifidobacterium lactis, Bifidobacterium animalis, Bifidobacterium breve, Bifidobacterium infantis, Bifidobacterium adolescentis, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus salivarius, Lactobacillus reuteri, Lactobacillus rhamnosus, Lactobacillus johnsonii, Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Streptococcus thermophilus, Lactococcus lactis, Lactococcus diacetylactis, Lactococcus cremoris, Lactobacillus bulgaricus, Lactobacillus helveticus, Lactobacillus delbrueckii, Escherichia coli and/or mixtures thereof.
[0086] The infant cereal in accordance with the present invention may, for example comprise non-replicating probiotic micro-organisms selected from the group consisting of Bifidobacterium longum NCC 3001, Bifidobacterium longum NCC 2705, Bifidobacterium breve NCC 2950, Bifidobacterium lactis NCC 2818, Lactobacillus johnsonii La1, Lactobacillus paracasei NCC 2461, Lactobacillus rhamnosus NCC 4007, Lactobacillus reuteri DSM17983, Lactobacillus reuteri ATCC55730, Streptococcus thermophilus NCC 2019, Streptococcus thermophilus NCC 2059, Lactobacillus casei NCC 4006, Lactobacillus acidophilus NCC 3009, Lactobacillus casei ACA-DC 6002 (NCC 1825), Escherichia coli Nissle, Lactobacillus bulgaricus NCC 15, Lactococcus lactis NCC 2287, or combinations thereof.
[0087] All these strains were either deposited under the Budapest treaty and/or are commercially available.
[0088] The strains have been deposited under the Budapest treaty as follows:
[0000]
Bifidobacterium longum NCC 3001:
ATCC BAA-999
Bifidobacterium longum NCC 2705:
CNCM I-2618
Bifidobacterium breve NCC 2950
CNCM I-3865
Bifidobacterium lactis NCC 2818:
CNCM I-3446
Lactobacillus paracasei NCC 2461:
CNCM I-2116
Lactobacillus rhamnosus NCC 4007:
CGMCC 1.3724
Streptococcus themophilus NCC 2019:
CNCM I-1422
Streptococcus themophilus NCC 2059:
CNCM I-4153
Lactococcus lactis NCC 2287:
CNCM I-4154
Lactobacillus casei NCC 4006:
CNCM I-1518
Lactobacillus casei NCC 1825:
ACA-DC 6002
Lactobacillus acidophilus NCC 3009:
ATCC 700396
Lactobacillus bulgaricus NCC 15:
CNCM I-1198
Lactobacillus johnsonii La1
CNCM I-1225
Lactobacillus reuteri DSM17983
DSM17983
Lactobacillus reuteri ATCC55730
ATCC55730
Escherichia coli Nissle 1917:
DSM 6601
[0089] Those skilled in the art will understand that they can freely combine all features of the present invention described herein, without departing from the scope of the invention as disclosed.
[0090] Further advantages and features of the present invention are apparent from the following Examples and Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0091] FIGS. 1 A and B show the enhancement of the anti-inflammatory immune profiles of probiotics treated with “short-time high temperatures”.
[0092] FIG. 2 shows non anti-inflammatory probiotic strains that become anti-inflammatory, i.e. that exhibit pronounced anti-inflammatory immune profiles in vitro after being treated with “short-time high temperatures”.
[0093] FIGS. 3 A and B show probiotic strains in use in commercially available products that exhibit enhanced or new anti-inflammatory immune profiles in vitro after being treated with “short-time high temperatures”.
[0094] FIGS. 4 A and B show dairy starter strains (i.e. Lc1 starter strains) that exhibits enhanced or new anti-inflammatory immune profiles in vitro upon heat treatment at high temperatures.
[0095] FIG. 5 shows a non anti-inflammatory probiotic strain that exhibits anti-inflammatory immune profiles in vitro after being treated with HTST treatments.
[0096] FIG. 6 : Principal Component Analysis on PBMC data (IL-12p40, IFN-γ, TNF-α, IL-10) generated with probiotic and dairy starter strains in their live and heat treated (140° C. for 15 second) forms. Each dot represents one strain either live or heat treated identified by its NCC number or name.
[0097] FIG. 7 shows IL-12p40/IL-10 ratios of live and heat treated (85° C., 20 min) strains. Overall, heat treatment at 85° C. for 20 min leads to an increase of IL-12p40/IL-10 ratios as opposed to “short-time high temperature” treatments of the present invention ( FIGS. 1 , 2 , 3 , 4 and 5 ).
[0098] FIG. 8 shows the enhancement of in vitro cytokine secretion from human PBMCs stimulated with heat treated bacteria.
[0099] FIG. 9 shows the percentage of diarrhea intensity observed in OVA-sensitized mice challenged with saline (negative control), OVA-sensitized mice challenged with OVA (positive control) and OVA-sensitized mice challenged with OVA and treated with heat-treated or live Bifidobacterium breve NCC2950. Results are displayed as the percentage of diarrhea intensity (Mean±SEM calculated from 4 independent experiments) with 100% of diarrhea intensity corresponding to the symptoms developed in the positive control (sensitized and challenged by the allergen) group.
DETAILED DESCRIPTION
Example 1
Methodology
[0100] Bacterial Preparations:
[0101] The health benefits delivered by live probiotics on the host immune system are generally considered to be strain specific. Probiotics inducing high levels of IL-10 and/or inducing low levels of pro-inflammatory cytokines in vitro (PBMC assay) have been shown to be potent anti-inflammatory strains in vivo (Foligne, B., et al., 2007, World J. Gastroenterol. 13:236-243).
[0102] Several probiotic strains were used to investigate the anti-inflammatory properties of heat treated probiotics. These were Bifidobacterium longum NCC 3001, Bifidobacterium longum NCC 2705, Bifidobacterium breve NCC 2950, Bifidobacterium lactis NCC 2818, Lactobacillus paracasei NCC 2461, Lactobacillus rhamnosus NCC 4007, Lactobacillus casei NCC 4006, Lactobacillus acidophilus NCC 3009, Lactobacillus casei ACA-DC 6002 (NCC 1825), and Escherichia coli Nissle. Several starter culture strains including some strains commercially used to produce Nestlé Lc1 fermented products were also tested: Streptococcus thermophilus NCC 2019, Streptococcus thermophilus NCC 2059, Lactobacillus bulgaricus NCC 15 and Lactococcus lactis NCC 2287.
[0103] Bacterial cells were cultivated in conditions optimized for each strain in 5-15 L bioreactors. All typical bacterial growth media are usable. Such media are known to those skilled in the art. When pH was adjusted to 5.5, 30% base solution (either NaOH or Ca(OH) 2 ) was added continuously. When adequate, anaerobic conditions were maintained by gassing headspace with CO 2 . E. coli was cultivated under standard aerobic conditions.
[0104] Bacterial cells were collected by centrifugation (5,000×g, 4° C.) and re-suspended in phosphate buffer saline (PBS) in adequate volumes in order to reach a final concentration of around 10 9 -10 10 cfu/ml. Part of the preparation was frozen at −80° C. with 15% glycerol. Another part of the cells was heat treated by:
[0105] Ultra High Temperature: 140° C. for 15 sec; by indirect steam injection.
[0106] High Temperature Short Time (HTST): 74° C., 90° C. and 120° C. for 15 sec by indirect steam injection
[0107] Long Time Low Temperature (85° C., 20 min) in water bath
[0108] Upon heat treatment, samples were kept frozen at −80° C. until use.
[0109] In vitro immunoprofiling of bacterial preparations:
[0110] The immune profiles of live and heat treated bacterial preparations (i.e. the capacity to induce secretion of specific cytokines from human blood cells in vitro) were assessed. Human peripheral blood mononuclear cells (PBMCs) were isolated from blood filters. After separation by cell density gradient, mononuclear cells were collected and washed twice with Hank's balanced salt solution. Cells were then resuspended in Iscove's Modified Dulbecco's Medium (IMDM, Sigma) supplemented with 10% foetal calf serum (Bioconcept, Paris, France), 1% L-glutamine (Sigma), 1% penicillin/streptomycin (Sigma) and 0.1% gentamycin (Sigma). PBMCs (7×10 5 cells/well) were then incubated with live and heat treated bacteria (equivalent 7×10 6 cfu/well) in 48 well plates for 36 h. The effects of live and heat treated bacteria were tested on PBMCs from 8 individual donors splitted into two separated experiments. After 36 h incubation, culture plates were frozen and kept at −20° C. until cytokine measurement. Cytokine profiling was performed in parallel (i.e. in the same experiment on the same batch of PBMCs) for live bacteria and their heat-treated counterparts.
[0111] Levels of cytokines (IFN-γ, IL-12p40, TNF-α and IL-10) in cell culture supernatants after 36 h incubation were determined by ELISA (R&D DuoSet Human IL-10, BD OptEIA Human IL12p40, BD OptEIA Human TNFα, BD OptEIA Human IFN-γ) following manufacturer's instructions. IFN-γ, IL-12p40 and TNF-α are pro-inflammatory cytokines, whereas IL-10 is a potent anti-inflammatory mediator. Results are expressed as means (pg/ml)+/−SEM of 4 individual donors and are representative of two individual experiments performed with 4 donors each. The ratio IL-12p40/IL-10 is calculated for each strain as a predictive value of in vivo anti-inflammatory effect (Foligné, B., et al., 2007, World J. Gastroenterol. 13:236-243).
[0112] Numerical cytokine values (pg/ml) determined by ELISA (see above) for each strain were transferred into BioNumerics v5.10 software (Applied Maths, Sint-Martens-Latem, Belgium). A Principal Component Analysis (PCA, dimensioning technique) was performed on this set of data. Subtraction of the averages over the characters and division by the variances over the characters were included in this analysis.
[0113] Results
[0114] Anti-inflammatory profiles generated by Ultra High Temperature (UHT)/High Temperature Short Time (HTST)-like treatments
[0115] The probiotic strains under investigation were submitted to a series of heat treatments (Ultra High Temperature (UHT), High Temperature Short Time (HTST) and 85° C. for 20 min) and their immune profiles were compared to those of live cells in vitro. Live micro-organisms (probiotics and/or dairy starter cultures) induced different levels of cytokine production when incubated with human PBMC ( FIGS. 1 , 2 , 3 , 4 and 5 ). Heat treatment of these micro-organisms modified the levels of cytokines produced by PBMC in a temperature dependent manner. “Short-time high temperature” treatments (120° C. or 140° C. for 15″) generated non replicating bacteria with anti-inflammatory immune profiles ( FIGS. 1 , 2 , 3 and 4 ). Indeed, UHT-like treated strains (140° C., 15 sec) induced less pro-inflammatory cytokines (TNFα, IFN-γ, IL-12p40) while maintaining or inducing additional IL-10 production (compared to live counterparts). The resulting IL-12p40/IL-10 ratios were lower for any UHT-like treated strains compared to live cells ( FIGS. 1 , 2 , 3 and 4 ). This observation was also valid for bacteria treated by HTST-like treatments, i.e. submitted to 120° C. for 15 sec ( FIGS. 1 , 2 , 3 and 4 ), or 74° C. and 90° C. for 15 sec ( FIG. 5 ). Heat treatments (UHT-like or HTST-like treatments) had a similar effect on in vitro immune profiles of probiotic strains ( FIGS. 1 , 2 , 3 and 5 ) and dairy starter cultures ( FIG. 4 ). Principal Component Analysis on PBMC data generated with live and heat treated (140° C., 15″) probiotic and dairy starter strains revealed that live strains are spread all along the x axis, illustrating that strains exhibit very different immune profiles in vitro, from low (left side) to high (right side) inducers of pro-inflammatory cytokines Heat treated strains cluster on the left side of the graph, showing that pro-inflammatory cytokines are much less induced by heat treated strains ( FIG. 6 ). By contrast, bacteria heat treated at 85° C. for 20 min induced more pro-inflammatory cytokines and less IL-10 than live cells resulting in higher IL-12p40/IL-10 ratios ( FIG. 7 ).
[0116] Anti-inflammatory profiles are enhanced or generated by UHT-like and HTST-like treatments.
[0117] UHT and HTST treated strains exhibit anti-inflammatory profiles regardless of their respective initial immune profiles (live cells). Probiotic strains known to be anti-inflammatory in vivo and exhibiting anti-inflammatory profiles in vitro ( B. longum NCC 3001, B. longum NCC 2705, B. breve NCC 2950, B. lactis NCC 2818) were shown to exhibit enhanced anti-inflammatory profiles in vitro after “short-time high temperature” treatments. As shown in FIG. 1 , the IL-12p40/IL-10 ratios of UHT-like treated Bifidobacterium strains were lower than those from the live counterparts, thus showing improved anti-inflammatory profiles of UHT-like treated samples. More strikingly, the generation of anti-inflammatory profiles by UHT-like and HTST-like treatments was also confirmed for non anti-inflammatory live strains. Both live L. rhamnosus NCC 4007 and L. paracasei NCC 2461 exhibit high IL-12p40/IL-10 ratios in vitro ( FIGS. 2 and 5 ). The two live strains were shown to be not protective against TNBS-induced colitis in mice. The IL-12p40/IL-10 ratios induced by L. rhamnosus NCC 4007 and L. paracasei NCC 2461 were dramatically reduced after “short-time high temperature” treatments (UHT or HTST) reaching levels as low as those obtained with Bifidobacterium strains. These low IL-12p40/IL-10 ratios are due to low levels of IL-12p40 production combined with no change ( L. rhamnosus NCC 4007) or a dramatic induction of IL-10 secretion ( L. paracasei NCC 2461) ( FIG. 2 ).
[0118] As a consequence:
[0119] Anti-inflammatory profiles of live micro-organisms can be enhanced by UHT-like and HTST-like heat treatments (for instance B. longum NCC 2705, B. longum NCC 3001, B. breve NCC 2950, B. lactis NCC 2818).
[0120] Anti-inflammatory profiles can be generated from non anti-inflammatory live micro-organisms (for example L. rhamnosus NCC 4007, L. paracasei NCC 2461, dairy starters S. thermophilus NCC 2019) by UHT-like and HTST-like heat treatments.
[0121] Anti-inflammatory profiles were also demonstrated for strains isolated from commercially available products ( FIGS. 3 A & B) including a probiotic E. coli strain.
[0122] The impact of UHT/HTST-like treatments was similar for all tested probiotics and dairy starters, for example lactobacilli, bifidobacteria and streptococci.
[0123] UHT/HTST-like treatments were applied to several lactobacilli, bifidobacteria and streptococci exhibiting different in vitro immune profiles. All the strains induced less pro-inflammatory cytokines after UHT/HTST-like treatments than their live counterparts ( FIGS. 1 , 2 , 3 , 4 , 5 and 6 ) demonstrating that the effect of UHT/HTST-like treatments on the immune properties of the resulting non replicating bacteria can be generalized to all probiotics, in particular to lactobacilli and bifidobacteria and specific E. coli strains and to all dairy starter cultures in particular to streptococci, lactococci and lactobacilli.
Example 2
Methodology
[0124] Bacterial Preparations:
[0125] Five probiotic strains were used to investigate the immune boosting properties of non-replicating probiotics: 3 bifidobacteria ( B. longum NCC3001, B. lactis NCC2818, B. breve NCC2950) and 2 lactobacilli ( L. paracasei NCC2461 , L. rhamnosus NCC4007).
[0126] Bacterial cells were grown on MRS in batch fermentation at 37° C. for 16-18 h without pH control. Bacterial cells were spun down (5,000×g, 4° C.) and resuspended in phosphate buffer saline prior to be diluted in saline water in order to reach a final concentration of around 10E10 cfu/ml. B. longum NCC3001, B. lactis NCC2818, L. paracasei NCC2461 , L. rhamnosus NCC4007 were heat treated at 85° C. for 20 min in a water bath. B. breve NCC2950 was heat treated at 90° C. for 30 minutes in a water bath. Heat treated bacterial suspensions were aliquoted and kept frozen at −80° C. until use. Live bacteria were stored at −80° C. in PBS-glycerol 15% until use.
[0127] In Vitro Immunoprofiling of Bacterial Preparations
[0128] The immune profiles of live and heat treated bacterial preparations (i.e. the capacity to induce secretion of specific cytokines from human blood cells in vitro) were assessed. Human peripheral blood mononuclear cells (PBMCs) were isolated from blood filters. After separation by cell density gradient, mononuclear cells were collected and washed twice with Hank's balanced salt solution. Cells were then resuspended in Iscove's Modified Dulbecco's Medium (IMDM, Sigma) supplemented with 10% foetal calf serum (Bioconcept, Paris, France), 1% L-glutamine (Sigma), 1% penicillin/streptomycin (Sigma) and 0.1% gentamycin (Sigma). PBMCs (7×10 5 cells/well) were then incubated with live and heat treated bacteria (equivalent 7×10 6 cfu/well) in 48 well plates for 36 h. The effects of live and heat treated bacteria were tested on PBMCs from 8 individual donors splitted into two separate experiments. After 36 h incubation, culture plates were frozen and kept at −20° C. until cytokine measurement. Cytokine profiling was performed in parallel (i.e. in the same experiment on the same batch of PBMCs) for live bacteria and their heat-treated counterparts.
[0129] Levels of cytokines (IFN-γ, IL-12p40, TNF-α and IL-10) in cell culture supernatants after 36 h incubation were determined by ELISA (R&D DuoSet Human IL-10, BD OptEIA Human IL12p40, BD OptEIA Human TNF, BD OptEIA Human IFN-γ) following manufacturers instructions. IFN-α, IL-12p40 and TNF-γ are pro-inflammatory cytokines, whereas IL-10 is a potent anti-inflammatory mediator. Results are expressed as means (pg/ml)+/−SEM of 4 individual donors and are representative of two individual experiments performed with 4 donors each.
[0130] In Vivo Effect of Live and Heat Treated Bifidobacterium breve NCC2950 in Prevention of Allergic Diarrhea
[0131] A mouse model of allergic diarrhea was used to test the Th1 promoting effect of B. breve NCC2950 (Brandt E. B et al. JCI 2003; 112(11): 1666-1667). Following sensitization (2 intraperitoneal injections of Ovalbumin (OVA) and aluminium potassium sulphate at an interval of 14 days; days 0 and 14) male Balb/c mice were orally challenged with OVA for 6 times (days 27, 29, 32, 34, 36, 39) resulting in transient clinical symptoms (diarrhea) and changes of immune parameters (plasma concentration of total IgE, OVA specific IgE, mouse mast cell protease 1, i.e. MMCP-1). Bifidobacterium breve NCC2950 live or heat treated at 90° C. for 30 min, was administered by gavage 4 days prior to OVA sensitization (days −3, −2 , −1, 0 and days 11, 12, 13 and 14) and during the challenge period (days 23 to 39). A daily bacterial dose of around 10 9 colony forming units (cfu) or equivalent cfu/mouse was used.
[0132] Results
[0133] Induction of secretion of ‘pro-inflammatory’ cytokines after heat treatment
[0134] The ability of heat treated bacterial strains to stimulate cytokine secretion by human peripheral blood mononuclear cells (PBMCs) was assessed in vitro. The immune profiles based on four cytokines upon stimulation of PBMCs by heat treated bacteria were compared to that induced by live bacterial cells in the same in vitro assay.
[0135] The heat treated preparations were plated and assessed for the absence of any viable counts. Heat treated bacterial preparations did not produce colonies after plating.
[0136] Live probiotics induced different and strain dependent levels of cytokine production when incubated with human PBMCs ( FIG. 8 ). Heat treatment of probiotics modified the levels of cytokines produced by PBMCs as compared to their live counterparts. Heat treated bacteria induced more pro-inflammatory cytokines (TNF-α, IFN-γ, IL-12p40) than their live counterparts do. By contrast heat treated bacteria induced similar or lower amounts of IL-10 compared to live cells ( FIG. 8 ). These data show that heat treated bacteria are more able to stimulate the immune system than their live counterparts and therefore are more able to boost weakened immune defenses. In other words the in vitro data illustrate an enhanced immune boost effect of bacterial strains after heat treatment.
[0137] In order to illustrate the enhanced effect of heat-treated B. breve NCC2950 (compared to live cells) on the immune system, both live and heat treated B. breve NCC2950 (strain A) were tested in an animal model of allergic diarrhea.
[0138] As compared to the positive control group, the intensity of diarrhea was significantly and consistently decreased after treatment with heat treated B. breve NCC2950 (41.1%±4.8) whereas the intensity of diarrhea was lowered by only 20±28.3% after treatment with live B. breve NCC2950. These results demonstrate that heat-treated B. breve NCC2950 exhibits an enhanced protective effect against allergic diarrhea than its live counterpart ( FIG. 9 ).
[0139] As a consequence, the ability of probiotics to enhance the immune defenses was shown to be improved after heat treatment.
Examples 3 and 4
[0140] The following compositions may be prepared:
[0141] For infants at the age of 4-6 months:
[0142] Ingredients: Rice flour, Maize Maltodextrin, Vitamin C, Mineral (Iron).
[0000]
Energy
232 Kj/15 g
Protein
1.0 g/15 g
Fat
0.2 g/15 g
Carbohydrates
12.5/15 g
(3.0 g from sugar)
probiotics
10 9 cfu/15 g UHT treated
Lactobacillus johnsonii La1
|
The present invention relates to the field of infant cereals. In particular, the present invention relates to the field of infant cereals that can be used to strengthen the immune system of the infant and/or that can be used to treat or prevent inflammatory disorders. For example these benefits can be provided by probiotic micro-organisms. An embodiment of the present invention relates to an infant cereal comprising non-replicating probiotic-micro-organisms, for example bioactive heat treated probiotic micro-organisms.
| 0
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Patent Application WO2015/057067 A1, filed Oct. 14, 2014, in the name of “Technische Universiteit Delft”, which PCT-application claims priority to Netherlands Patent Application with Serial No. 2011609, filed Oct. 14, 2013, in the name of “Technische Universiteit Delft”, and the specifications and claims thereof are incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0003] Not Applicable.
COPYRIGHTED MATERIAL
[0004] Not Applicable.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The present invention is in the field of papermaking and relates in particular to sizing paper.
[0007] 2. Technical Field
[0008] In the papermaking field, it is known that most paper is made of cellulose and/or hemicellulose fibres. These fibres contain hydroxyl groups. Hydrogen bonding between water molecules and the hydroxyl groups of the cellulose and/or hemicellulose fibres is energetically favourable and thus water can readily wet and penetrate paper. In other words, paper is not water resistant.
[0009] A problem that this poses is that for paper to be useful in e.g. printing, writing, packaging, wrapping, and construction applications, it needs to have a degree of water resistance.
[0010] To overcome this problem, paper is usually treated with sizing chemicals either during manufacture of the paper (internal sizing) or by surface treatment of the paper (surface sizing).
[0011] Sizing relates to a process for making paper at least partially water resistant by the addition of polymers. Typical examples of sizing chemicals include: carbohydrates, such as starches, gums, and alginates; amphipathic compounds, such as rosin, and alkyl ketene dimer; and, alkenyl succinic anhydride.
[0012] Methods for sizing paper are known from e.g. CN101864700A which recites a surface treatment method capable of improving surface smoothness of light paper and reducing printing ink absorbability. WO2002/012623 A recites a process for sizing paper which comprises adding to an aqueous suspension containing cellulosic fibres, and optional fillers, (i) an anionic or cationic sizing dispersion; and (ii) a sizing promoter comprising a cationic organic polymer having one or more aromatic groups, and an anionic polymer having one or more aromatic groups, the anionic polymer being a step-growth polymer, a polysaccharide or a naturally occurring aromatic polymer, forming and draining the obtained suspension, wherein the sizing dispersion and sizing promoter are added separately to the aqueous suspension.
[0013] Problems associated with such methods are e.g. that the sizing chemicals used are typically expensive; they may be available only in limited supply; they are produced using methods that are damaging to the environment; and whose production is far from carbon-neutral.
[0014] It is an object of the present invention to overcome one or more of the disadvantages of the prior art, without jeopardizing functionality and advantages.
BRIEF SUMMARY OF THE INVENTION
[0015] In a first aspect, the present invention relates to use of extracellular polymeric substances obtainable from granular sludge for sizing paper or any paper-like product.
[0016] At present, the sludge produced from wastewater treatment processes, including granular sludge, is considered as a waste product, having no further use. On top of that, costs of waste disposal are 500-600ε per ton of sludge in the Netherlands. This represents roughly one third of the wastewater treatment costs.
[0017] Surprisingly, it has been found that extracellular polymeric substances obtainable from granular sludge are suitable and effective for sizing paper. The present invention therefore provides a commercially and environmentally very interesting application of this ‘waste’ product.
[0018] Granules making up granular sludge are aggregates of microbial cells self-immobilized through extracellular polymeric substances into a spherical form without any involvement of carrier material. A characterising feature of granules of granular sludge is that they do not significantly coagulate during settling (i.e. in a reactor under reduced hydrodynamic shear).
[0019] Extracellular polymeric substances make up a significant proportion of the total mass of the granules.
[0020] Extracellular polymeric substances comprise high-molecular weight compounds (typically>5 kDa) secreted by microorganisms into their environment. Extracellular polymeric substances are mostly composed of polysaccharides and proteins, but include other macro-molecules such as DNA, lipids and humic substances.
[0021] Extracellular polymeric substances obtainable from granular sludge (preferably obtained from granular sludge) do not require further purification or treatment to be used for sizing paper. Wherein the extracellular polymeric substances are obtained from granular sludge the extracellular polymeric substances are preferably isolated from bacteria (cells) and/or other non-extracellular polymeric substances. An example of a suitable technique for isolating extracellular polymeric substances from granular sludge is given in the detailed description of the invention and accompanying example.
[0022] Advantageously, granules of granular sludge can be readily removed from a reactor by e.g. physical separation, settling, centrifugation, cyclonic separation, decantation, filtration, or sieving to provide extracellular polymeric substances in a small volume. Compared to separating material from a liquid phase of the reactor this means that neither huge volumes of organic nor other solvents (for extraction), nor large amounts of energy (to evaporate the liquid) are required for isolation of the extracellular polymeric substances.
[0023] Thereby the present invention provides a solution to one or more of the above mentioned problems.
[0024] Advantages of the present description are detailed throughout the description.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The present invention relates to use of extracellular polymeric substances obtainable from granular sludge for sizing paper or any paper-like product.
[0026] In an example, the extracellular polymeric substances comprise a major portion consisting of exopolysaccharides, and a minor portion, such as less than 30% w/w, typically less than 10% w/w, consisting of lipids and/or other components more hydrophobic than the exopolysaccharides.
[0027] The weight percentages (w/w) throughout the description are based on a total weight of a (dry) composition.
[0028] Extracellular polymeric substances obtained from granular sludge having a major portion of exopolysaccharides and a minor portion of lipids have been found to provide very effective water resistance to paper, in particular when the extracellular polymeric substances are used for surface sizing, i.e. where the extracellular polymeric substances are at an air-interface of the paper.
[0029] In an example, the extracellular polymeric substances comprise at least 50% w/w exopolysaccharides, preferably at least 60% w/w exopolysaccharides, most preferably at least 75% w/w exopolysaccharides, such as at least 90% w/w exopolysaccharides. Extracellular polymeric substances obtained from granular sludge have been found to be particularly effective sizing agents when they have a high exopolysaccharide content. The exopolysaccharide content is preferably not 100%, as a remainder has been found to contribute to the present advantages effects.
[0030] In an example, the granular sludge is aerobic granular sludge or anammox granular sludge. Extracellular polymeric substances obtained from aerobic granular sludge and anammox granular sludge have been shown to be particularly effective as sizing agents. Research by the inventors has shown that exopolysaccharides of the extracellular polymeric substances obtained from aerobic granular sludge are alginate-like in character, and in fact perform even better than alginate per se as a sizing chemical. Sizing with alginate per se is known in the prior art.
[0031] Aerobic granular sludge and anammox granular sludge, and the processes used for obtaining them are known to a person skilled in the art. For the uninitiated, reference is made to Water Research, 2007, doi:10.1016/j.watres.2007.03.044 (anammox granular sludge) and Water Science and Technology, 2007, 55(8-9), 75-81 (aerobic granular sludge).
[0032] In an example, the extracellular polymeric substances have been obtained from aerobic or anammox granular sludge by an isolation (i.e. separation) method comprising: alkaline extraction of the granular sludge thereby forming extracellular polymeric substances containing extractant; acid precipitation of extracellular polymeric substances from the extractant; and collecting the extracellular polymeric substance-containing precipitate.
[0033] It has been found that this method is particularly effective for obtaining extracellular polymeric substances from granular sludge, such as from aerobic and anammox granular sludge, in good yield.
[0034] In an example, the granular sludge has been substantially produced by bacteria belonging to the order Pseudomonadaceae, such as pseudomonas and/or Azotobacter bacteria (aerobic granular sludge); or, by bacteria belonging to the order Planctomycetales (anammox granular sludge), such as Brocadia anammoxidans, Kuenenia stuttgartiensis or Brocadia fulgida ; or, combinations thereof. Extracellular polymeric substances from granular sludge produced by these bacteria are effective sizing agents, even when applied in an amount in the range of 0.1-5% w/w extracellular polymeric substances/final product.
[0035] In an example, the exopolysaccharides are block-copolymers comprising uronic acid (e.g. mannuronic acid and guluronic acid) residues.
[0036] In an example, the extracellular polymeric substances are in aqueous solution at a concentration in the range of 0.1-30% w/w, preferably 1-10% w/w, most preferably 4-10% w/w, such as 5-8% w/w. Such provides a solution having suitable characteristics for spraying. Thereby a uniform layer of the extracellular polymeric substances can be provided on paper, (largely) after the paper has been produced.
[0037] In an example, the extracellular polymeric substances are added to the paper forming solution and/or to the paper, i.e. forming part of a paper production process.
[0038] In an example, the extracellular polymeric substances are bleached, such as by treatment with hydrogen peroxide. By bleaching the extracellular polymeric substances, they can be used for sizing white and coloured paper without changing the colour of the paper. Surprisingly, bleaching with e.g. hydrogen peroxide only slightly reduces the sizing performance of the extracellular polymeric substances (the amount applied is preferably increased by around 20-40% compared (relative) to unbleached extracellular polymeric substances).
[0039] In a second aspect, the present invention relates to a method for sizing paper comprising: (i) feeding a reactor with (a) waste water, such as obtained from manufacturing of paper thereby providing a carbon source, and (b) granular sludge forming bacteria; (ii) operating the reactor under suitable conditions for generating and growing granular sludge; (iii) separating at least a proportion of granules of the granular sludge, such as by physical separation, settling, centrifugation, cyclonic separation, decantation, filtration, or sieving; (iv) separating extracellular polymeric substances from the collected aerobic granular sludge; and (v) sizing paper with the extracellular polymeric substances.
[0040] In an example, the granular sludge forming bacteria belong to the order Pseudomonas and Azotobacter , and step (ii) above comprises: (ii) (a) in a first stage maintaining the reactor under low oxygen concentration conditions (anaerobic) during a predetermined period of time at a predetermined temperature for accumulating carbon in cells of the bacteria; and (ii) (b) in a second stage maintaining the reactor under high oxy-gen concentration conditions (aerobic) during a predetermined period of time at a predetermined temperature for growing the bacteria in granular form so as to form granules. The temperature is preferably in a range of 5-30° C., such as 10-25° C.
[0041] The oxygen concentration in the first stage is preferably as low as possible, e.g. with respect to a reactor set-up. The period of time in the first stage is in the order of 0.1-8 hours, preferably 0.25-4 hours, more preferably 0.5-2 hours, such as 1 hour.
[0042] The oxygen concentration in the second stage may be similar or equal to environmental conditions. It is noted that an oxygen concentration of 10% of a saturation value is considered high enough in this respect. In an example the second stage time is 3-48 hours, preferably 6-24 hours, more preferably 10-18 hours, such as 12 hours.
[0043] In an example, the granular sludge forming bacteria belong to the order Planctomycetales; wherein in step (i) the waste water further comprises an ammonium source; and wherein step (ii) comprises maintaining the reactor under high oxygen concentration conditions (aerobic).
[0044] In an example, the bacteria belonging to the order Pseudomonadaceae, such as pseudomonas and/or Azotobacter , preferably cultivated bacteria.
[0045] In a third aspect, the present invention relates to sized paper obtainable by a method according to the second aspect of the invention.
[0046] In a fourth aspect, the present invention relates to sized paper comprising extracellular polymeric substances from aerobic granular sludge and/or anammox granular sludge. In an amount of 0.1-5% w/w extracellular polymeric substances/final product.
[0047] The invention will hereafter be further elucidated with reference to the Example and Drawings which are exemplary and explanatory of nature and are not limiting the scope of the invention. To the person skilled in the art it may be clear that many variants and combinations thereof, being obvious or not, may be conceivable falling within the scope of protection, defined by the present claims.
EXAMPLE
[0048] Using Extracellular Polymeric Substances Obtain able (EPS) from aerobic granular sludge to increase water resistance of paper fibre.
SUMMARY OF FIGURES
[0049] FIG. 1 —Contact angle measurement. After the water drop fell on the paper (b), the contact angle (the angle at which the liquid-vapor interface meets the solid-liquid interface) of the water drop was monitored for 120 seconds (c→d).
[0050] FIG. 2 —Morphology of extracellular polymeric substances from aerobic granular sludge by atomic force microscopy. The fibre-like structure covers the surface and forms film; the globules distribute on the film and point to the air.
[0051] FIG. 3 —Diagram of extracellular polymeric substances at the surface between water and air. The hydrophilic parts cover the surface and hydrophobic parts point to the air.
[0052] FIG. 4 —Pyrolysis-gas chromatograms of extracellular polymeric substances from aerobic granular sludge. Cn and Cn:1 indicates chain length of saturated and unsaturated compounds.
[0053] FIG. 5 —Size distribution profiles of extracellular polymeric substances from aerobic granular sludge by size exclusion chromatography.
[0054] FIG. 6 —Water drops on paper (a): raw paper; (b): paper coated with 5% extracellular polymeric substances; (c): paper coated with 8% bleached extracellular polymeric substances.
[0055] FIG. 7 —The contact angle of miliQ water on the raw paper, paper coated with the commercial sizing chemical WRP 50C and with bleached and unbleached extracellular polymeric substances as a function of time.
[0056] FIG. 8 —Diagram of the water resistance effect of extracellular polymeric substances on cellulosic fibre. a: cellulosic fibres are porous (there are empty voids between the fibres), water is easily wet and penetrate the fibre network. b: The extracellular polymeric substances are fibre-like material, but these fibres are 20 nm in width, which is at least 1000 times thinner than cellulosic fibre. Extracellular polymeric substance forms a film on cellulose fibre. Due to the existence of the hydrophobic part of extracellular polymeric substance, the water drop does not easily wet and run through the fibre.
DETAILED DESCRIPTION OF FIGURES
[0057] The figures are further detailed in the description of the experiments below.
EXAMPLES/EXPERIMENTS
Methods
[0058] Aerobic Granular Sludge for Investigation
[0059] The aerobic granular sludge from which the extracellular polymeric substances of the present example were obtained was collected from the Nereda® pilot plant, operated by DHV at the wastewater treatment plant Epe, The Netherlands. The reactor was fed with municipal sewage. The influent consisted of approximately 25% of slaughterhouse wastewater, which was discharged in the sewage system. Average parameters of the influent were: CODtotal 585 mg/L, suspended solids 195 mg/L, NH 4 —N 55 mg/L and PO 4 —P 6.3 mg/L. The reactor was operated in Sequencing Batch (SBR) mode for biological phosphate and nitrogen removal. Operational details were described in Lin et al. (2010). After start-up, biomass concentration in the reactor was maintained around 8 to 10 g TSS/L. Oxygen in the reactor was controlled between 2 to 3 mg/L during aeration. Temperature and pH were not controlled in this system and depended on the incoming sewage. During steady operation, aerobic granular sludge was collected and sieved to give granules with a diameter>2 mm.
[0060] The granules were then dried.
[0061] Isolation of Extracellular Polymeric Substances
[0062] Dried granules (0.5 g) were homogenized for 5 min (Labgen tissue homogenizer, Cole-Parmer, USA) and extracted in 80 ml 0.2M Na 2 CO 3 at 80° C. for 1 h. After centrifuging at 15,000 rpm for 20 min, the pellet was discarded. The supernatant pH was adjusted to 2 by adding 0.1 M HCl. The precipitate was collected by centrifugation (15,000 rpm, 30 min), washed by dideionized water until effluent pH reached 7, and dissolved in 0.1 M NaOH. Extracellular polymeric substances in the supernatant were precipitated by the addition of cold absolute ethanol to a final concentration of 80% (vol/vol). The precipitate was collected by centrifugation (15,000 rpm, 30 min), washed three times in absolute ethanol and lyophilized. The resulting mixture of extracellular polymer substances is an example of extracellular polymeric substances (EPS) obtainable from granular sludge according to the invention.
[0063] Ash content of the EPS was measured according to the standard method (APHA).
[0064] Characterisation of EPS
[0065] Before characterisation, EPS (0.5 g) was dissolved in 15 mL of NaOH solution (0.05M). The pH was then adjusted to 7.0 by 0.05 M HCl. Finally the solution was placed inside a dialysis tubing (3500 MWCO) and dialyzed against demineralized water for 48 hours to remove loosely bound ions and lyophilized.
[0066] Morphology of EPS by Atomic Force Microscopy
[0067] Imaging of EPS was carried out in air at ambient temperature and humidity using freshly-cleaved mica pre-treated by 3 mM NiCl 3 . Aliquots (2 ul) of extracellular polymeric substances (5 mg/L) were deposited onto mica surfaces for 10 s, and then quickly removed by the pipette. Those surfaces were air dried (1 h) in a dust-free enclosure. Samples were scanned with a Digital Instruments Multimode atomic force microscope (Veeco nanoscopy iva dimension 3100, Veeco Inc., Santa Barbara, USA).
[0068] EPS Composition Analysis by Pyrolysis-Gas Chromatography-Mass Spectrometry
[0069] Pyrolysis was carried out on a Horizon Instruments Curie-Point pyrolyser. The lyophilized extracellular polymeric substances were heated for 5 s at 600° C. The pyrolysis unit was connected to a Carlo Erba GC8060 gas chromatograph and the products were separated by a fused silica column (Varian, 25 m, 0.25 mm i.d.) coated with CP-Sil5 (film thickness 0.40 μm). Helium was used as carrier gas. The oven was initially kept at 40° C. for 1 min, next it was heated at a rate of 7° C./min to 320° C. and maintained at that temperature for 15 min. The column was coupled to a Fisons MD800 mass spectrometer (mass range m/z 45-650, ionization energy 70 eV, cycle time 0.7 s). Identification of the compounds was carried out by their mass spectra using a NIST library or by interpretation of the spectra, by their retention times and/or by comparison with literature data.
[0070] Lipid Content of EPS
[0071] For lipids analysis in the extracellular polymeric substances, the methods proposed by Smolders et al. (1994) were used with modification. Pure fatty acids (Sigma-Aldrich) were used as external standard. Freeze-dried extracellular polymeric substance samples and fatty acid standards were weighed using an analytical balance and transferred into tubes with screw caps. One milligramme of C15 fatty acid in 1-propanol was used as internal standard. 1.5 mL of a mixture of concentrated HCl and 1-propanol (1:4), and 1.5 mL of dichloroethane were added into the tubes and heated for 2 h at 100° C. After cooling, free acids were extracted from the organic phase with 3 mL water. One millilitre of the organic phase was filtered over water-free sodium sulphate into GC vials. The lipids in the organic phase were analyzed by gas chromatography (model 6890N, Agilent, USA) equipped with a FID, on an HP Innowax column.
[0072] EPS Molecular Weight Analysis
[0073] Size exclusion chromatography was performed with a Superdex 75 10/300 GL column (AKTA Purifier System, GE Healthcare). Elution was carried out at room temperature using PBS at constant 0.4 mL/min flow rate and detection was monitored by following the absorbance of the eluted molecules at 210 nm. Superdex 75 10/300 GL (GE Healthcare) column separates molecules of 1 000 to 150 000 Daltons (Da) with a total exclusion volume of 7.9 mL. Measurement of the elution volume of dextran standards (1000 Da, 5000 Da, 12000 Da, 25 000 Da and 50 000 Da) led to the calibration equation:
[0000] Log(MW)=6.212−0.1861Ve
MW: Molecular Weight of the molecule in Dalton (Da) Ve: elution volume in mL (assayed at the top of the peak)
[0076] Chromatogram profiles were recorded with UNICORN 5.1 software (GE Healthcare). Peak retention times and peak areas were directly calculated and delivered by the program.
[0077] Bleaching of EPS
[0078] EPS (1 g) was put into H 2 O 2 (30%) for 24 hours, collected by centrifuge at 4000 rpm and lyophilized.
[0079] Sizing with EPS and Water Resistance Property of Paper after Sizing with EPS
[0080] 1 mL of both the unbleached (5% w/w) and bleached EPS (8% w/w) were sprayed evenly on pieces of raw paper (10 cm×10 cm, 96 g/m2, without the addition of any sizing chemicals, supplied by Kenniscentrum Papier en Karton, the Netherlands), and air-dried. 1 ml of one commercial sizing chemical (Impermax WRP 50C, supplied by Kenniscentrum Papier en Karton), was sprayed on the same kind of paper with the same size and air-dried. The change of contact angle (the contact angle is the angle at which the liquid-vapor interface meets the solid-liquid interface) with time of a drop of miliQ water on these air-dried pieces of paper was recorded and measured by KSV CAM200 ( FIG. 1 ).
[0081] The change of contact angle with time of a drop of miliQ water on the raw paper itself was also recorded and measured as a control.
[0082] On each piece of paper, the contact angle was measured at 5 different places randomly; the average value and standard deviation were calculated.
[0083] Results
[0084] Extracellular polymeric substances were obtained from aerobic granular sludge as described above. The extracellular polymeric substances were then characterised and used in sizing paper. The sized layer was finally tested for its effectiveness.
[0085] Morphology of Extracellular Polymeric Substances by the Atomic Force Microscope
[0086] See FIG. 2 .
[0087] The yield of extracellular polymeric substances was 160±4 mg/g (VSS ratio).
[0088] The extracellular polymeric substances have a fibre-like structure. The width of the fibre is around 20 nm ( FIG. 2 ). The fibres extend along the surface and entangle with each other, forming a web-like structure that covers the whole surface of the mica. This demonstrates that the extracellular polymeric substances have a perfect film-forming property and can form a continuous film on a surface. The thickness of extracellular polymeric substance film is around 4 nm. In addition to the fibres, there are a few globules distributing on the fibres and pointing to the air. The height of the globules can reach 15 nm, which is 2 times higher than the thickness of extracellular polymeric substance film. Due to the significant difference in height, the globules looked much brighter than the fibres under the atomic force microscope. As the sample was prepared by depositing extracellular polymeric substance water solution on a surface and air dried, those globules extending out of the surface and pointing to the air must have hydrophobic property.
[0089] Therefore, the extracellular polymeric substances have both a hydrophilic part and hydrophobic part. When the extracellular polymeric substances stay at the surface between water and air, the hydrophilic parts spread along the surface, forming a film and the hydrophobic parts distribute on the film and pointing to the air ( FIG. 3 ).
[0090] Extracellular Polymeric Substance Composition Analysis
[0091] The composition of the extracellular polymeric substances was analysed by pyrolysis-GC-MS. In the spectrum ( FIG. 4 ), polysaccharide-derived products such as 5-methylfuraldhyde and levoglucosenone were identified, implying a contribution from carbohydrate units to the extracellular polymeric substance sample. Lipids and wax esters composed of C16 and C18 fatty acids and alcohol moieties of the same carbon lengths were found as well. By contrast, all pyrolysis products of proteins and other combinations of amino acids were much less prominent, indicating that they were relatively minor components of the extracellular polymeric substances. In addition, there is a so-called unresolved complex mixture consisting of many similar compounds that co-elute and which cannot be identified by their mass spectra at present. In brief, the pyrolysis-GC-MS analysis displays that, comparing to carbohydrates and lipids, proteins are a minor part of the extracellular polymeric substances.
[0092] The lipid content in the extracellular polymeric substances was measured as 8.2±0.9 mg/g extracellular polymeric substances.
[0093] Since normally polysaccharides are hydrophilic and lipids are hydrophobic, comparing to the morphology in FIG. 2 , it can be assumed that the fibre-like structure which forms film on the surface are mostly polysaccharides and those globules pointing towards the air are mostly lipids.
[0094] Molecular Weight of Extracellular Polymeric Substances
[0095] The size distribution profile of the extracellular polymeric substances by size exclusion chromatography is shown in FIG. 5 . There are 5 fractions with different elution volume. The fraction with the shortest elution volume, which has the highest molecular weight, separate well with other fractions. The three fractions with an elution volume between 13 ml to 17 ml co-eluted. The molecular weight of these 5 fractions and their percentages are listed in Table 1. It can be clearly seen that most of isolated extracellular polymeric substances (94%) has a molecular weight of more than 5.8 KDa, and about ⅓ of the extracellular polymeric substances has a molecular weight higher than 150 KDa. As carbohydrates with higher molecular weight tend to extend on the surface, it could be an explanation for the perfect film-forming property of the isolated extracellular polymeric substances.
[0000]
TABLE 1
Molecular weight of different fractions in extracellular
polymeric substances isolated from granular sludge and their percentage.
Percentage of the
Elution volume of the
Molecular weight
fraction
peak (ml)
(Da)
(% peak area)
7.83
7 × 10 4
29.74
13.48
1.44 × 10 4
18.82
15.57
5.79 × 10 3
45.15
17.58
2.15 × 10 3
4.42
20.13
6.56 × 10 2
1.87
[0096] Use of Extracellular Polymeric Substances as a Sizing Chemical in Papermaking
[0097] The effect of bleached and unbleached extracellular polymeric substances on increasing the water resistance of paper is shown in FIG. 6 . For unsized paper, once a drop of water falls on the surface, it is absorbed immediately by the paper and rapidly spreads. In contrast, the water retains the shape of the drop on extracellular polymeric substances and bleached extracellular polymeric substances coated paper sheets.
[0098] To evaluate the water resistance property, the contact angle between the water droplet and the surface of the paper was monitored within 120 seconds ( FIG. 7 ). Water in contact with the unsized paper is absorbed in less than 1 s. But for paper sheets sized with a 5% extracellular polymeric substances solution and 8% bleached extracellular polymeric substances solution, their water resistance property is comparable to paper sheet sized with a commercial sizing product (10% of alkenyl succinic anhydride). Both of their initial contact angles are higher than 100, which fulfil the requirement of an adequately sized paper. The extracellular polymeric substances as obtained from granular sludge have a brown colour, bleaching with H 2 O 2 results in a colourless substance.
[0099] It is thought that the good sizing performance of extracellular polymeric substances obtainable from granular sludge is at least in part due to it comprising both hydrophilic and hydrophobic components. Such also distinguishes it from sizing agents presently used.
[0100] This is explained with reference to FIG. 8 .
[0101] The width of the cellulosic fibre in paper is around 20 μm; when a cellulose fibre network is formed, significant amount of empty voids present between the fibres. However, the width of the fibre of the extracellular polymeric substance is on average, only 20 nm. Thus, it is thought that these nanofibres can entangle with each other and form a web-like film which covers both the surface of the cellulosic fibres and the empty voids. At the same time, the hydrophobic globules extend to the air. When a water drop comes into contact with the surface of the paper sheet sized with extracellular polymeric substances, the repulsion force from the hydrophobic globules will keep the water as a drop. Even with water in contact with the hydrophilic fibres of the extracellular polymeric substance, it will be absorbed only slowly by extracellular polymeric substances due to swelling without wetting the cellulosic fibre and spreading.
[0102] Extracellular polymeric substances from granular sludge provide an effective and green alternative to current commercial sizing agents.
[0103] The invention although described in detailed explanatory context may be best understood in conjunction with the accompanying examples and figures.
[0104] It should be appreciated that for commercial application it may be preferable to use one or more variations of the present system, which would similar be to the ones disclosed in the present application and are within the spirit of the invention.
|
An invention in the field of papermaking that relates in particular to sizing paper. Problems with state of the art methods are that the sizing chemicals used are typically expensive; may be available only in limited supply; are produced using methods that are damaging to the environment; and whose production is far from carbon-neutral. It is an object of the present invention to provide an alternative to the methods of the prior art and to overcome one or more of the above mentioned disadvantages.
| 3
|
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The present invention relates to an electronic sewing machine, and more particularly to a stitch pattern to be sewn to adjust the balance of fabric feeding amounts in the forward and rearward directions. With the development of an electronic memory for computer sewing machines which may store almost limitless amount of the data, it has become possible to stitch any patterns including very complicated patterns of a large number of the stitches formed in the forward and rearward fabric feeding directions such as alphabet letters, the images of flowers and animals etc.
The electronic control sewing machine usually stores, as pattern signals, a needle amplitude amount and a fabric feed amount for stitches which form patterns, and transmits said pattern signals to an amplitude control motor and a feed control motor. In this kind of sewing machine, a physical space within the mechanism for producing the patterns has more problems as the conventional pattern generation due to cams housed in the mechanical structure of the sewing machine. Therefore, it is possible to freely increase the number of the patterns stored in the sewing machine and the stitching number of the individual patterns. As a result various fine patterns or complicated patterns have been produced.
The mechanism of the electronic control sewing machine controls the forward feed and the rearward feed by reverse rotations around the control of the feed amount "0" of the feed control motor. The respective members of the feed control mechanism have manufacturing tolerances, so that a value of a signal indicative of the feed amount and an actual feed amount are more or less different.
Sewing machines were manufactured, where respective members of the feed control mechanisms were within the manufacturing tolerances. After their feed reference points have been adjusted, the actual feeding amounts were measured for the values of the signals of the feed amounts, and the relation therebetween was standardized, as shown in FIG. 1, in accordance with the measuring data.
As shown in FIG. 1, the broken line indicates that the feeding amounts and the feeding signals are in proportion 1:1 as desired both in the forward and rearward feeding directions. However, in the actual mechanism, the fabric feed reference point is to be usually unstable and is inevitably determined at a point on the lateral axis which is more or less spaced from the center 0. Thus if the feed reference point is once determined at a place other than the center 0, for example, on the plus side of the lateral axis, the forward feeding amounts will be constant with the respective feeding signals, but the rearward feeding amounts will be remarkably different from the forward feeding amounts even though the former may be constant in the rearward direction. This will considerably deform the patterns of the stitches formed with both the forward and rearward feeding amounts. In order to form the stitches of the same feeding amounts in the rearward feeding direction with the stitches of the feeding amounts in the forward feeding direction, it is necessary to displace the fabric feeding reference point to a place on the minus side of the lateral axis from the place on the plus side at the same distance from the center 0 as shown by solid lines in FIG. 1. Such a displacement of the feeding reference point is required each time the fabric feeding direction is changed during the sewing of a pattern.
Since the number of the patterns stored in the sewing machine and the stitching number of the pattern are increased, a first problem resides in that the existing adjustment is insufficient to regulate the feed reference point, and a second problem is that the existing pattern designing results in a big difference in shape between the data and the actual stitching pattern, and this fact could not be ignored.
The second problem could be solved in designing. That is, in the conventional method, the pattern was not stitched as requested by the signal as shown in FIG. 1, and such a difference was ignored. A model pattern was prepared as being stitched along the dotted line shown, and the feed amount signal was decided.
If the model pattern is simple and the stitching number is not many in the initial period of operation, the difference between the model pattern and the shape of the stitching pattern is not outstanding. However, as the stitching number increases and the model pattern becomes complicated, the difference between the feed signal value and the actual feed amount influences finished products.
This problem may be solved by distinguishing the signal in accordance with the standardized solid line in FIG. 1 from the model pattern when making the pattern data, and arranging that the model pattern and the stitching pattern be practically made of the same shape.
The standardization means such an operation which, in order to provide the same shape practically as described above, decides the quantitative relation between the value of the signal of the feeding amount and the actual feeding amount. In other words, the standardization means the operation which obtains relation between the measuring data of the actual feeding data and the value of the signal of said amount by a sort of a weighted average operation.
An outline of the feed control mechanism will be mentioned for explaining the above-mentioned first problem. The feed control mechanism especially controls the feed control motor in the forward feed and the rearward feed by rotations opposite to each other around the feeding amount "0". The feed control mechanism is, in a transmission path of the feed controlling amount, provided with a first feed controller for adjusting the feed reference point when the sewing machine is set up at the maker's side, and with a second feed controller which is set under the neutral condition of the operation when adjusting the feed reference point, and which may be operated from the outside of the sewing machine.
With respect to the adjustment of the feed reference point when the sewing machine is set up and regulated, the feed reference point is adjusted by operating the first feed controller. For this aim, the curve of the feeding amount as shown in FIG. 1 is determined for each of the sewing machines. Since it takes a long time for calculating the feed reference point, the feed control motor is firstly energized at the signal value "0" of the feed amount, and the actual feeding amount is set to be "0" by operating the first feed controller. However, since the actual feeding amount "0" has a width along the lateral axis as shown in FIG. 1, the controlling is still rough. Secondly several kinds of representative patterns are stitched, and the first feed controller is operated while observing finished stitches.
The representative pattern is such a pattern which is outstanding out of regularity if the feed refernce point is not correctly adjusted. A tulip pattern as one example is shown in FIG. 2. With respect to the figures 0, 15, 30 in the same, the full amplitude is equally divided into 30 parts and amplitude cordinates are set as 0, 1, 2, . . . 30 from the right. 0 is a right basic line, 15 is a middle basic line and 30 is a left basic line. The figure belonging to the pattern indicates a stitching number counting from a 1st stitch of an initial one. In this example, a discriminating portion is a distance between the stitches combining the 11th stitch--the 12th stitch and the stitches combining the 22nd stitch--the 23rd stitch. Since this distance is widened or draws "X" by crossing the threads, the adjusting condition of the feed can be discriminated while stitching the tulip pattern. However, 10 stitches are between the 12th stitch and the 22nd stitch, and these stitches determine the thickness of the tulip stem. As far as the electronic sewing machine forms simple patterns with lesser stitching number, there are not any special problems in the adjustment while stitching said representative pattern. The stitching number of individual patterns stored in the sewing machine has been increased, and the stitches of letters, characters or fine abstract patterns have been formed. Representative patterns have not been inherently prepared for adjusting the feed reference point. For abstract patterns, the shapes of patterns should be necessarily decided, taking aesthetic elements into consideration, and the abstract patterns may be used as the accidential result to regulate the feed reference point. The stitching number has not been sufficient for discriminating the adjusting condition of the feed reference point.
In the adjustment while stitching the representative patterns as conventionally, since the patterns are stored within the sewing machine, the stitched pattern is fed forward and under a presser foot, and fed in succession backward of the presser foot. Therefore, several patterns are stitched which are more in stitching number than the existing ones, otherwise the pattern is stitched and pulled out while stopping the sewing machine so as to discriminate the stitching condition by the present adjustment. It takes a long time for regulation.
Similar problems arise at the customers' sides where the adjustment of the feed reference point has been finished, but the balance between the forward feed and the rearward feed is temporally irregular due to quality of the fabric used or others.
SUMMARY OF THE INVENTION
It is an object of the present invention is to provide patterns for adjusting a feeding amount of the electronic control sewing machine.
This and other objects of the invention are attained by a specific pattern stitched for adjusting a fabric feeding amount of an electronic sewing machine storing stitch control data for a plurality of different patterns and having a needle swingable within a predetermined laterally extended range and a fabric feeding device, said needle and fabric feeding device being controlled by said stitch control data to produce various stitch patterns within said predetermined range defined by a first end needle position, a second end needle position and an intermediate needle position, and having an adjusting device operated to adjust the fabric feeding amount which is determined by said fabric feeding device controlled by said stitch control data in forward and rearward feeding directions, said specific pattern comprising:
(a) a first group of stitches produced substantially at one of said first and second end needle positions of said predetermined range;
(b) a second group of stitches produced between said one end needle position and said intermediate needle position of said predetermined range;
(c) a third group of stitches produced between said intermediate needle position and the other of said first and second end needle positions, said third group of stitches including stitches produced in the forward and rearward feeding directions and frequently and commonly used in a plurality of different patterns stored in the sewing machine; and
(d) a fourth group of stitches produced between said intermediate needle position and said one end needle position, so as to be positionally compared with said second group of stitches for conformation of a balance between the feeding amounts in a forward and rearward feeding directions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing a standardized relation between values of signals indicative of the feeding amount and the actual feeding amount;
FIG. 2 is a view showing one example of a representative stitching pattern stored in the sewing machine and used for adjusting the feed reference point according to the prior art;
FIG. 3 is a view showing a pattern adjusting the feeding amount in accordance with an embodiment of the invention;
FIGS. 4 and 5 are views showing examples of positioning relations in a 2nd stitching group of the patterns adjusting the feeding amount during adjusting the feed reference point;
FIG. 6 is a view showing stitches of the pattern adjusting the feeding amount; and
FIG. 7 is a partial perspective view of the conventional sewing machine for producing a pattern according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be explained in reference to the embodiment shown in the attached drawings. FIG. 3 shows a pattern for adjusting the feeding amount. With respect to the figures 0, 15, 30 in FIG. 3, the full feed amplitude is equally divided into 30 parts and amplitude cordinates are set as 0, 1, 2, . . . 30 from the right. 0 is a right basic line, 15 is a middle basic line and 30 is a left basic line.
The pattern for adjusting the feeding amount comprises a 1st stitching group for stitching whole patterns in the reverse feed, a 2nd stitching group which coincides when the adjustment of the feed reference point is proper, and a 3rd stitching group which is formed with a plurality of the forward feed and rearward feed stitches, and is positioned in opposition to the 1st stitching group relative to the middle basic line, and gives to the second stitching group accumulative errors of the forward feed and the rearward feed.
In the present embodiment, the 1st stitching group is composed of the 1st stitch, and 2nd stitch, and the 36th to 38th stitches, and is for stitching the whole pattern with the reverse feed. The 36th to 38th stitches are formed after the 2nd and 3rd stitching groups have been formed.
The 3rd stitch and the 35th stitch, and the 4th stitch and the 34th stitch coincide in the signals, respectively, and form said 2nd stitching group. If the feed reference point were not adjusted properly, the thread between the 3rd and 4th stitches and that between the 34th and the 35th stitches would be crossed with as shown in FIG. 4, or reversely open as shown in FIG. 5. Since four threads before and after these stitching threads are connected not at the right angle but in obliquity, they are easily observed, and the feed reference point may be easily regulated by discriminating it. The distance between the 2nd stitching group and the 4th stitch and the 34 stitch is combined by the 3rd stitching group composed of a plurality of stitches formed with a plurality of the forward feeds and rearward feeds. In the present embodiment, the feeds of 30 times (30 stitches) are carried out by means of the 3rd stitching group from the feed after the 4th stitch to the feed after the 33rd stitch. If the feed reference point were not proper, the accumulative errors of the forward feed and the rearward feed stitches would be given to the 2nd stitching group,
As mentioned above, the stitching numbers of the patterns have been increased, and the stitchings of the letters or fine abstract patterns have been formed, and these stitching numbers exceed 40 to 100 stitches.
Patterns which are outstanding in irregularity of the pattern shape form the stitching group corresponding to the 3rd stitching group in the patterns for adjusting the feeding amount, and are such patterns having the stitching group corresponding to the connected 2nd stitching group. In these patterns, the stitching numbers forming the stitching group corresponding to the 3rd stitching group, are often merely parts of all the stitching numbers of the patterns, and stitching patterns corresponding to said parts may be designed. The feed is adjusted at high precision for the pattern which has the maximum of the stitching number forming the stitching group corresponding to the 3rd stitching group, and the 30 stitches of the 3rd stitching group of the pattern for adjusting the feed reference point are determined in order not to make the patterns irregular.
The pattern for adjusting the feeding amount according to the invention is stitched with the reverse feed, differently from other patterns, so that the stitched pattern is not positioned under the presser foot (P) as shown in FIG. 6, and is fed towards the operator in succession. Therefore, the feed reference point is adjusted while the pattern is stitched.
With reference to FIG. 7 it will be seen that a needle bar 1 having a needle 2 secured to the lower end thereof is operatively connected to an upper drive shaft 3 of the sewing machine and is vertically reciprocated by rotation of the upper drive shaft.
The needle bar 1 is supported on a swingable frame 4 which is swingably mounted on a machine housing 5 and is connected, through a rod 6, to an actuator such as a stepping motor (not shown) which is operated by selected stitch control data for a stitch pattern to control the swinging amplitude of the needle within a predetermined laterally extended range.
A loop taker 7 is rotatably arranged in an arm bed 8 and has a worm gear 9 which is in engagement with a gear 10 which is secured to a lower drive shaft 11 which is operatively connected to the upper drive shaft 3.
The lower drive shaft 11 is rotated in association with the rotation of the upper drive shaft 3 to rotate the loop taker 7 in timed relation with the vertical reciprocation of the needle 2.
A rocking member 12 is roackably arranged in the arm bed 8, and it has a vertical arm 13 pivotably supporting a U-shaped cam follower 14 which is in engagement with a cam 15 secured to the lower drive shaft 11 for rotation therewith.
The U-shaped cam follower 14 has a free end having a small block 16 pivoted thereto by a pin 17. The block 16 is in sliding engagement with a groove 18 of a feed regulator 19 which is connected through a shaft 20 to an actuator such as a stepping motor (not shown) which is operated by selected stitch control data for a stitch pattern to control the angular position of the feed regulator 19 while the selected pattern is stitched.
Further the rocking arm 12 has vertical arms 21, 22 which pivotally support a feeding frame 23 having a set of feed dogs 24. The feeding frame 23 is swingingly moved up and down as shown by arrows A and B by a cam (not shown) around pivots 25, 26 while the sewing machine is driven.
When the lower drive shaft 11 is rotated, the cam 15 is rotated to swingingly move the U-shaped cam follower 14 up and down around the pivot 27. Since the block 16 of the cam follower 14 is in sliding engagement with the groove 18 of the feed regulator 19, the vertical swinging movement of the cam follower 14 is changed into a reciprocation in a horizontal plane as shown by arrows C and D. The amount of the horizontal reciprocation is varied in dependence upon the angular positions of the feed regulator 19.
Therefore, the rocking member 12 is rocked around a pivot 28, and accordingly the feeding frame 23 is reciprocatingly moved in the horizontal plane as shown by the arrows C and D while the feeding frame 23 is swingably moved up and down as shown by the arrows A and B.
It is therefore apparent that the fabric feeding amount resulted by the feed dogs 24 and the fabric feeding direction are variable in dependence upon the angular positions of the feed regulator 19.
Herein, the explanation will be made to the adjustment of the feed reference point while stitching the pattern for adjusting the feeding amount. The feed control mechanism especially controls the feed control motor during the forward feed and the rearward feed by rotations opposite directions relative to the feeding amount reference "0". The feed control mechanism is, in a transmission path of the feed controlling amount, provided with a first feed controller for adjusting the feed reference point when the sewing machine is set up at the maker's side, and with a second feed controller which is set under the neutral condition of the operation when adjusting the feed reference point, and which may be operated from the outside of the sewing machine.
With respect to the adjustment of the feed reference point when the sewing machine is set up and adjusted, the feed reference point is adjusted by operating the first feed controller. For this purpose, the curve of the feeding amount as shown in FIG. 1 is defined for each of sewing machine. Since it takes a long time for calculating the feed reference point, the feed control motor is firstly energized at the signal value "0" of the feed amount, and the actual feeding amount is set to be "0" by operating the first feed controller. However, since the actual feeding amount "0" has a certain width along the lateral axis, as shown in FIG. 1, the controlling is still rough. Secondly several kinds of representative patterns are stitched, and the first feed controller is operated while observing finished stitches thereof.
Since the 3rd stitching group is composed of 30 stitches, the discrimination is highly precise and accordingly the feed reference point is adjusted at high precision.
The pattern for adjusting the feeding amount of the invention is stitched with the reverse feed, differently from other patterns, so that the stitched pattern is not positioned under the presser foot (P) as shown in FIG. 6, and is fed towards the operator in succession.
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 specific patterns for adjusting a fabric feeding amount differing from the types described above.
While the invention has been illustrated and described as embodied in a specific pattern for adjusting a fabric feeding amount, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
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.
|
A specific pattern for adjusting a fabric feeding amount in an electronic sewing machine with a storage for storing stitch control data for a plurality of different patterns. The specific pattern includes a 1st stitching group stored in the sewing machine and used for stitching the whole pattern in a reverse feed, a 2nd stitching group which coincide with the first one when a feed reference point is adjusted properly, and at least a 3rd stitching group which is stitched by a plurality of forward feeds and rearward feeds and is positioned in opposition to the 1st stitching group relative to a middle basic line, and gives to the 2nd stitching group accumulative errors of the forward feed and the rearward feed, so that a balance between the feeding amounts in a forward and a rearward directions of stitching is conformed.
| 3
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is concerned with containment, use and storage of large volumes of liquids and, more particularly, to a containment system located in a body of water.
2. Description of the Prior Art
The devisement of underwater storage systems has been described in U.S. Pat. Nos. 2,383,840, 2,894,268, and 3,113,699. These systems contemplated the storage of petroleum products such as gasoline and fuel oil and the delivery of such to sea-going vessels and the like. Because petroleum products have a specific gravity much less than water, it is necessary to provide anchoring means to prevent the storage containers from floating to the surface. It is also necessary to construct the containers to withstand the pressure differential created by the buoyancy force of the storaged petroleum products in water. This force becomes extremely significant at depths greater than about thirty feet such that the container construction costs become prohibitive at depths therebeyond.
To withstand the effects of water currents and buoyancy forces, elaborate steel housings have been developed to enclose flexible containers or rigid steel tanks have been used which are secured to concrete bases. Obviously, the corrosive forces of water, particularly salt water, render the above systems not feasible for the containment of water wherein large volumes must be stored inexpensively.
SUMMARY OF THE INVENTION
A novel system is provided for the containment, utilization and storage of water or other liquids having a similar specific gravity, within a body of water. Containment and storage is effected inexpensively with elongated thin-walled flexible containers which are provided with a top portion having an opening maintained at about water level with buoyant means. The buoyant means may include a floating structure upon which is supported a header assembly and conduit means in communication with the opening for transporting liquids into and out of the container.
More than one container can be used to store liquids and/or function as a waste water treatment system by tranfer of treated and decanted liquid to successive containers. Alternatively, a container may be provided with an inner net lining and used as a fish or plant cultivation system. When the contents of the container are to be examined or removed, the net may be elevated for easy access.
It is contemplated that the present system will be adapted to accumulate and store overflow or excess fresh water from inland reservoirs or drainage systems. A single container may hold 50,000 or less to over six million gallons of water depending on the depth of water in which it is immersed and the practical limits of container construction and handling.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of an embodiment of the invention showing an elongated flexible storage container descending from the surface of a large body of water.
FIG. 2 is a perspective view of an embodiment of the invention showing two containers similar to the container of FIG. 1 connected in series with conduit means for the successive treatment of waste water.
FIG. 3 is a perspective view of another embodiment of the invention showing a container similar to the container of FIG. 1 provided with an inlet pipe near the container bottom for extracting cooled water therefrom.
FIG. 4 is a perspective view of a further embodiment of the invention showing a container similar to the container of FIG. 1 provided with an inner closed end netting for retrieving cultured fish.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1 of the drawings, which depicts a containment system 8, an elongated flexible container 10 is shown having a closed bottom portion 12 and a top portion 14 having an opening 16. Substantially the entire container is immersed within a large body of water 20 and located offshore a distance dictated by the depth and bottom structure of the body of water relative to the cost of transporting liquids to and from land.
The top portion 14 is supported at sea level with a floating structure 24. The floating structure serves to maintain the opening 16 above water level so that the liquid contents 26 may be protected from contamination from the surrounding body of water 120. To further inhibit such contamination a cover 30 shown in phantom is provided over the opening 16.
It will be appreciated that the floating structure 24 may be incorporated into or used in conjunction with a platform 32 which may overlie the opening 16 and thereby take the place of cover 30. The platform 32 includes a header assembly 34 which is connected to conduit means 36.
It is contemplated that the header assembly will include the necessary pipe and connecting assemblies such as control valves, pressure relief valves, and miscellaneous interconnecting assemblies to facilitate the flow of liquids into and out of the container through the conduit means. It is further contemplated that pumping means may be included within the header assembly supported by the platform 32 or such pumping means may be located on land. Depending on the size of the floating structure the platform may also include a small building structure 38 for housing accessory equipment and/or for enclosing the header assembly for protection from the effects of the environment.
In the embodiment shown in FIG. 1 the length of the bag is depicted as being on the order of about one-half mile long with a diameter of about 20 feet. A container of this size may be filled with about six million gallons of fresh water. The container may be constructed of extruded and blown plastic film which is impermeable to liquids such as polyethylene or polyvinylchloride. Optionally, the plastic walls may be reinforced with nylon or may be biaxially oriented during extrusion for insuring sidewall strength against the rigors and hazards of being immersed in a large body of water.
The container may be wound into a roll in a well-known manner following the extrusion thereof and simply unwound by gravity by allowing it to free fall and descend into the body of water while maintaining the top portion above water.
If the container is used to contain fresh water having a specific gravity of about 62.3 pounds per cubic foot and is immersed in sea water having a specific gravity of approximately 62.5 pounds per cubic foot, there will not be any significant pressure differential across the sidewalls.
It will be noted, however, that a slight head will be created as the container is filled to overcome the resistance of filling the container and because of the slight difference in specific gravities. As such, the floating structure is preferably provided with an inner wall of a height sufficient to provide for such head and further to inhibit the overflow of surrounding salt water resulting from high waves or the like. In this regard it will be understood that the opening 16 is in communication with the atmosphere such that there is no pressure whatsoever placed upon the water contained within the system. Since the specific gravities are substantially similar and because of the lack of positive pressure against the contained liquid, there will be no pressure differential across the walls of the container and there will be no buoyant forces operating against the container to force it to the water surface. As such, the container can be constructed with the aforementioned conventional extruded plastic film without the necessity of steel housings or concrete foundations.
To facilitate the off-loading of the container into the body of water the bottom portion may be provided with a small amount of ballast (not shown) to facilitate its downward descent. It will also be noted that even though a floating structure and platform are shown, the opening may be located at the overflow viaduct of a dam or reservoir with the container body extending outwardly into a lake or ocean. In this manner, the use of long pipes for transporting liquid into and out of the container immersed offshore will be obviated as well as the use of pumping means to fill the container.
Referring now to FIG. 2, there is shown two containers 50 and 51 which are connected in series by interconnecting pipes 52. In this embodiment, waste water from land will flow through pipe 54 into the interior of container 50. Appropriate settling agents and chemicals may be injected by control means 56 through pipe 52 to cause impurities contained in the waste water to precipitate and settle to the container bottom and form a sludge 58. After a suitable settling period, the clarified liquid in the upper portion of the container may be decanted therefrom by conduit 52 and transferred to container 51. Control means 56 may again be used to inject disinfecting chemicals or the like to treat the clarified liquid for subsequent use as irrigation water. Depending on the desirability of more treatment, additional containers may be connected in series for further handling prior to use on shore. The primary container 50 is optionally provided with connecting lines 59 to the bottom portion thereof. This is to facilitate the removal of the sediments 58 by allowing the bottom to be drawn near the top opening for dispensation of the sediment materials. It is further contemplated that the container 50 may be removed from the conduit structure and transported several miles out to the open sea for dispersal of the sediments by simply inverting the container.
FIG. 3 is a schematic perspective depicting the use of container 60 as a heat exchanger. In this embodiment, ballast or weight means are secured to the lower portion thereof to maintain the container in a substantially vertical position within the ocean. It is contemplated that the container shall be over a thousand feet in length so that water contained in the bottom portion will be cooled by the ambient cool ocean water prevalent at such depths. In this system hot water inlet pipe 64 delivers warm water to the top portion of the container and stand pipe 65, having an opening 66 near the bottom of the container, is used as an inlet for cool water and delivery through a pumping assembly 72 back to land by pipe 67. To minimize the energy required for this system, the flow of hot water to the container may be accomplished by syphon means from cooling tower water means inland (not shown). The power for pumping of water back to such cooling tower means may be effected by a windmill system 70 supported on floating platform 74. Such a system for pumping water from deep wells is well known. Its use near an ocean shoreline is especially feasible due to the almost constant winds that exist at such locations.
The perspective of FIG. 4 depicts a container 80 immersed in a body of water and provided with a co-extensive closed-end inner netting 84. The container may hold fresh water and the surrounding water may be salt water or vice versa depending on the type of fish 86 being cultivated therein. The netting may be of woven thread or may be a wire network. The system is provided with means to elevate the bottom 88 to provide access to the fish by lifting them near the top opening 90. This is accomplished with a line 94 connecting the bottom portion 88 of net 84. A boom and winch means 96 is used to raise the net and retrieve the cultured fish.
The top opening is provided with a floating structure 92 in the same manner as that shown in FIG. 1. As aforementioned, the opening 90 may be enclosed with a floating platform 100 or a cover (not shown) as desired.
It will be understood that the system may also be used to cultivate plants and the like whereby the liquid within the container will be provided with an enriched nutrient solution to encourage the plant growth therein.
It will be appreciated that the invention as described in the aforementioned embodiments provides special advantages for society in view of the growing overcrowded land conditions wherein the need for large reservoirs, steel tanks and the like will be obviated. Additionally, because of the recurrent extremes in weather, the system will provide an inexpensive means for the storage of fresh water during periods of excess for use during later periods of drought. Because the containment system is maintained at about atmospheric pressure via an opening above sea water, there is no pressure differential or buoyant forces operating against the container sidewalls. As such, the miscellaneous super-structures described by the prior art and the expensive materials of construction of the prior art containers are eliminated.
Note that while preferred embodiments have been described, it will be apparent that other modifications and improvements may be made to the essential elements of the invention without departing from the spirit and scope thereof. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrative embodiments but only by the scope of the appended claims.
|
An underwater system for confining large volumes of liquids comprising an elongated sock-like closed container immersed in a body of water. The container has thin flexible sidewalls and is provided with an opening located adjacent the water surface. It is contemplated that the system will be used for liquids having a specific gravity about that of water so that no substantial pressure differential will exist across the container sidewalls.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/042,628, filed Jan. 9, 2002 now abandoned, which is a continuation of U.S. patent application Ser. No. 09/572,355, filed May 17, 2000, now abandoned.
BACKGROUND OF THE INVENTION
The present invention generally relates to a method and an apparatus for preventing injuries to occupants in a vehicle, and more particularly to an improved method and apparatus for preventing at least one front seat of a vehicle from collapsing into a rear seat area during collisions with a vehicle occupant safety net thereby mitigating whiplash injuries to occupants.
The use of safety devices in vehicles in order to increase safety measures to occupants therein are well known. Such safety measures have been primarily designed to mitigate injuries to the occupants during vehicle collisions, or even sudden stops. The transportation industry, mainly comprised of automobile, railroad, airline, and sea vessel businesses, has realized over time that such potential risks to their occupants may have dire consequences in incidents immediately mentioned above. Therefore, as a response to such circumstances, the transportation industry has spent enormous financial resources and time in a constant effort to improve their safety measures to minimize injuries to their occupants.
For example, safety belts are widely utilized in the transportation industry to improve safety measures to the occupants. More specifically, the safety belts maintain the occupants on the seats of the vehicles in order to prevent any outward projections of the occupants during vehicle collisions or sudden stops. The safety belts have been effective in mitigating injuries by preventing the occupants from colliding with the interior of the vehicle, or being thrown out therefrom. However, even though the safety belts may be effective in the above context, such belts are not a solution to the problem stated below.
More specifically, during most rear impacts of vehicles, namely, automobiles, the vehicle seats may collapse rearwardly at fairly low load levels and impact speeds. Upon encountering the collapse of such seats, many problems may result therefrom. For instance, when the front driving seat collapses, the driver may fall away from the vehicle controls, brakes, steering, etc., which makes it difficult to avoid subsequent accident possibilities.
Furthermore, falling rearward as the seat collapses flat may cause the occupant of the seat to slide out from the seat belt, thus allowing the occupant to hit his or her head on other portions of the interior of the vehicle. Moreover, in extreme cases, such phenomenon may cause the occupant to be ejected from the vehicle. Additionally, with the recent advice that all infants should be placed in infant seats located in the rear seats, the collapse of the front seats may cause damage to the infant maintained in the infant seat. Even further, the rearward collapse of the front seats may additionally make it difficult to extricate passengers from the rear seat area of the vehicle following collisions.
Thus, there has long been a need in the industry, and in the transportation industry in particular, for a method and an apparatus for preventing the front seats of the vehicle from collapsing into the rear seat area during vehicle collisions. In particular, there is a need to prevent such collapses in order to better resolve not only the problems stated above, but also to further mitigate whiplash injuries to the occupants of the vehicle.
The present invention addresses and overcomes the above-described deficiency of conventional vehicle seats by positioning a vehicle occupant safety net between the front seats and the rear seat area of the vehicle. Moreover, the vehicle occupant safety net is strategically secured to the vehicle in order to prevent rearward collapse of the seats thereby mitigating injuries to the occupants, namely, reducing head and neck rearward extensions which may result in whiplash motion. In addition, the safety net also prevents such collapsing of the seats into the rear seat area where the occupants, such as infants and children, may be seated. Furthermore, the vehicle occupant safety net is user-friendly to the occupants by being retractable within a net roller when its use is not desired.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a method of preventing at least one front seat of a vehicle from collapsing into a rear seat area during collisions with a vehicle occupant safety net thereby mitigating whiplash injuries to occupants. The method provides for positioning the vehicle occupant safety net between the at least one front seat and the rear seat area of the vehicle. The safety net is then secured to the vehicle. Moreover, the safety net is sized and configured to prevent the at least one front seat from collapsing rearwardly into the rear seat area during collisions thereof to mitigate whiplash injuries of the occupants.
More specifically, the safety net further comprises a net roller. The safety net may be advanceable through the net roller to be retracted therein. Furthermore, the safety net may be pullable from the net roller to extend therefrom. Such safety net may be fabricated from a lightweight, high-strength unitary material.
In addition, a body of the vehicle comprises the at least one front seat having a backside. In one embodiment, safety net may be positioned to extend generally parallel to the backside of the at least one front seat. In another embodiment, the safety net may be positioned to extend in abutting contact the backside of the at least one front seat. Furthermore, the vehicle may be an automobile.
In accordance with the present invention, the safety net has a first longitudinal edge, in which the first edge may be attached to an upper portion of a support structure of the vehicle body. The support structure of the vehicle body may be a roll bar mounted therein, in which the roll bar may be positioned between the at least one front seat and the rear seat area. Moreover, the first edge may be slidably engaged to the net roller, wherein the net roller may be attachable to the upper portion of the support structure.
Furthermore, the safety net has a second longitudinal edge, in which the second edge may be attached to side portions of the support structure. More specifically, a first strap with a snap and a second strap with a ring may attach the second edge to the side portions of the support structure. The first strap and the second strap may each connect around the side portions opposite from each other, wherein the first strap may engage across the second edge to interlock the snap with the ring of the second strap.
The second longitudinal edge may further be attached to a lower structure of the vehicle body. Such lower structure may be a floor of the vehicle. In particular, the second edge has at least one endpiece therealong, wherein the at least one endpiece may be extendable from the second edge for attachment to the lower structure of the vehicle.
Moreover, the at least one endpiece may extend from ends of the second edge for attachment to the lower structure of the vehicle, wherein the at least one endpiece is generally perpendicular to the second edge. A releasable hook and a bolt may attach the at least one endpiece to the lower structure. Specifically, the releasable hook may be attached on an exposed end of the at least one endpiece for engagement to the bolt mounted on the lower structure of the vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
These as well as other features of the present invention, will become more apparent upon reference to the drawings wherein:
FIG. 1 is a perspective view of a vehicle with a vehicle occupant safety net constructed in accordance with a preferred embodiment of the present invention;
FIG. 1A is a side view of the vehicle seat and safety net shown in FIG. 1;
FIG. 2 is an elevational view of the safety net shown in FIG. 1;
FIG. 3 is an elevational view of the safety net with an alternative way of attachment to the vehicle shown in FIG. 1;
FIG. 4 is an elevational view of a net roller with the safety net partially retracted therein;
FIG. 5 is an exploded view of a releasable hook and a bolt of the safety net shown in FIG. 1; and
FIG. 6 is an exploded view of a releasable clip and a bolt of the safety net shown in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein the showings are for purposes of illustrating preferred embodiments of the present invention only, and not for, purposes of limiting the same, FIG. 1 perspectively illustrates a vehicle 10 with a vehicle occupant safety net 20 constructed in accordance with a preferred embodiment of the present invention. In this regard, the vehicle 10 may be any variety of vehicles, such as an automobile, a boat, an airplane, a train, or any type of transportable body. It is important to note that the automobile in FIG. 1 is only a structure of the vehicle, the at least one endpiece being generally perpendicular to the second edge. symbolic representation of the vehicle 10 , and the application of the present invention should not solely be limited to thereof. It will be appreciated by those of ordinary skill in the art that the present invention may be applicable to any vehicle 10 , as will be explained more fully below.
Referring now to FIGS. 1, 1 A, 2 , 3 and 4 , the safety net 20 may be fabricated from any types of material, but a lightweight, high-strength unitary material is preferred. More specifically, it may be advantageous for the safety net 20 to be fabricated from high-strength material in order to better ensure prevention of rearward collapses of front seats 30 into a rear seat area 40 . In this regard, the unitary characteristic of the safety net 20 may enhance the prevention of such collapses since the unitarily fabricated safety net 20 may not readily avail itself to tearing and/or any form of internal breach. Thus, the unitarily fabricated safety net 20 may provide additional strength to prevent the front seats 30 from collapsing rearwardly into the rear seat area 40 .
Moreover, the safety net 20 is defined by a first longitudinal edge 22 and a second longitudinal edge 24 . More specifically, the first longitudinal edge 22 is generally in parallel relationship with the second longitudinal edge 24 . Furthermore, the first longitudinal edge 22 and the second longitudinal edge 24 are spaced apart, wherein a netting 26 of the safety net 20 is placed therebetween. The netting 26 further has uniformly distributed apertures 28 therethrough, as the apertures 28 are spread vertically and horizontally throughout the netting 26 in an ordered configuration. However, it will be contemplated by those of ordinary skill in the art that such configuration may be dependent upon the desires of a manufacturer, a driver, or an occupant of the vehicle 10 , and therefore should not solely be limited to the configuration depicted in FIGS. 1-3.
In addition, the safety net 20 further comprises a net roller 50 . The net roller 50 and the safety net 20 are slidably engaged to each other. More specifically, The net roller 50 is attached to the first longitudinal edge 22 of the safety net 20 . The net roller 50 and the first longitudinal edge 22 are slidably engaged to each other, wherein the safety net 20 may be movable with respect to the net roller 50 . The net roller 50 and the first longitudinal edge 22 may be engaged to each other in any fashion, whether it be conventional or in creative manner. For example, a bond or a sewing procedure may be utilized to attach the net roller 50 and the first longitudinal edge 22 . In the alternative, the net roller 50 may mechanically grasp onto the first longitudinal edge 22 for the same purpose. Simply put, there are a plurality of ways in which the first longitudinal edge 22 may be engaged to the net roller 50 .
Furthermore, as stated in the above paragraph, the safety net 20 may be slidably movable with respect to the net roller 50 . The safety net 20 may advance through the net roller 50 . Specifically, the safety net 20 may be wrapped around the outside of the net roller 50 when its use is not desired. In the alternative, the safety net 20 may further be advanceable through the inside of the net roller 50 to be retracted therein. Simply put, the safety net 20 may be rolled up within the net roller 50 when its use is not desired. It will be contemplated by those of ordinary skill in the art that any conventional methods may be utilized in retracting the safety net 20 within the net roller 50 . For instance, a turn knob method may be used to manually wind up the safety net 20 within the net roller 50 . Moreover, the safety net 20 may be triggered towards the net roller 50 simply by a mechanical arrangement that releases a piece that grips the safety net 20 in place. In addition, it may be appreciated by those of ordinary skill in the art that the safety net 20 may be applicable with a device utilized for a window shade or the like, and a locking retractor, such as safety belt. It should be noted that a variety of methods may be used in performing this function.
Consistent with the above paragraph, it should further be mentioned that the safety net 20 may be extendable from the net roller 50 . More specifically, the safety net 20 may be pullable from the net roller 50 to extend therefrom. As stated above, there are a plurality of ways of doing this. For one, the turn knob method may be used to manually wind down the safety net 20 from the net roller 50 to a desired extension/position. Alternatively, the mechanical gripping piece arrangement may be used, wherein the gripping piece may hold the safety net 20 in place when the desired extension/position is reached. Even further, if the safety net 20 is simply wrapped around the outside of the net roller 50 , then the safety net 20 may be manually unwrapped to its desired extension/position.
The vehicle 10 comprises a vehicle body 60 . The vehicle body 60 is defined by the front seats 30 , the rear seat area 40 , a support structure 70 , and a lower structure 80 . More specifically, the front seats 30 of the vehicle body 60 has respective backsides 32 . Furthermore, the support structure 70 is mounted to the lower structure 80 of the vehicle body 60 . The support structure 70 of the vehicle body 60 may be a roll bar, B-pillars having roof ribs, C-pillars, or the like. Additionally, the lower structure 80 may be a floor of the vehicle body 60 .
The safety net 20 may be positioned between the backsides 32 of the front seats 30 and the rear seat area 40 of the vehicle body 60 . The safety net 20 may be positioned to extend generally parallel to the backsides 32 of the front seats 30 . Moreover, the safety net 20 may further be positioned to extend in abutting contact the backside 32 of the front seats 30 . Simply put, as long as the safety net 20 is able to prevent the front seats 30 from collapsing rearwardly into the rear seat area 40 , there is no specific place where the safety net 20 should be placed. However, for ease of attachment purposes, it is recommended that the safety net 20 be placed generally in proximity to the support structure 70 and the backsides 32 of the front seats 30 .
Furthermore, it may be important to place the safety net 20 in such a way that it covers the entirety of the backsides 32 of the front seats 30 . It should be noted that the safety net 20 may simply extend to cover only partial area of the backsides 32 . However, in order to increase the effectiveness of the safety net 20 , it is recommended that the safety net 20 be utilized in a way that it extends over the entirety of the backsides 32 of the front seats 30 , including head restraints, if any. This way, not only does the safety net 20 prevent the front seats 30 from collapsing into the rear seat area 40 , but simultaneously prevents any whiplash injuries of occupants as well by maintaining the front seats 30 , including the head restraints, in an upright position as possible during collisions. Furthermore, it may be beneficial to allow the front seats 30 to be movable in its normal context by having the safety net 20 to be adjustable to accommodate such movement, wherein the safety net 20 may be locked in place after the desired position of the front seats 30 are reached.
In addition, the safety net 20 may further need to be secured to the vehicle 10 , namely, the vehicle body 60 . The support structure 70 comprises an upper portion 72 and opposing side portions 74 . The first longitudinal edge 22 of the safety net 20 may be attached to the upper portion 72 of the support structure 70 . More specifically, the first longitudinal edge 22 is attached to the net roller 50 , in which the net roller 50 may be attached to the upper portion 72 of the support structure 70 . The net roller 50 comprises grasping members 52 which may mechanically attach to the upper portion 72 . The grasping members 52 may be adjustable to conform to the different thicknesses of the upper portion 72 , in which subsequent tightening may be applied. Alternatively, the first longitudinal edge 22 may directly attach to the upper portion 72 by a conventional sewing or bonding procedure.
The safety net 20 may further need to be secured to the side portions 74 of the support structure 70 . It will be contemplated by those of ordinary skill in the art that the safety net 20 may be attached to the side portions 74 in any manner, such as simply tying the safety net 20 to the side portions 74 with suitable ropes, cables, cords or the like. However, a first strap 90 with a ring 92 and a second strap 100 with a snap 102 may be utilized to secure the safety net 20 to the side portions 74 . More specifically, the first strap 90 may be looped around one of the side portions 74 , as the second strap 100 may also be looped around the opposing side portion 74 .
The first strap 90 or the second strap 100 may engage the second longitudinal edge 24 of the safety net 20 , or some intermediate parallel edge. For instance, the first strap 90 may run across the length of the second longitudinal edge 24 to connect to the second strap 100 . More specifically, the first strap 90 may run through every aperture 28 in closest proximity to the second longitudinal edge 24 of the safety net 20 in order to better secure the safety net 20 to the side portions 74 . Thereafter, the ring 92 of the first strap 90 may interlock with the snap 102 of the second strap 100 .
The first strap 90 may further comprise a belt retractor 96 . More specifically, the belt retractor 96 may be formed anywhere along the first strap 90 , but it is preferred that the belt retractor 96 be placed near any of one of the ends of the first strap 90 . The belt retractor 96 may roll up the first strap 90 sidewardly, wherein the first strap 90 is slidably movable in relation to the belt retractor 96 . The belt retractor 96 may further allow the first strap 90 to be pulled out to any length necessary, and lock the first strap 90 in place thereafter, to permit the front seats 30 to be adjustable to its desired position. Simply put, the belt retractor 96 may function to adjust the first strap 90 to the desired length.
In the alternative, the safety net 20 of the present invention may be attached to the side portions 74 in a different way than above. More specifically, the first strap 90 may comprise strap snaps 93 on its respective ends rather than having a ring 92 . The second strap 100 is secured to one of the side portions 74 , as a third strap 106 is engaged to the opposite thereof. The second strap 100 may have a second ring 104 in lieu of the snap 102 , as the third strap 106 has a third ring 108 . Thereafter, the first strap 90 may run through the second longitudinal edge 24 of the safety net 20 , or through some intermediate parallel edge of the safety net 20 , to interlock the strap snaps 93 with the respective second ring 104 of the second strap 100 and the third ring 108 of the third strap 106 .
Moreover, the safety net 20 may further need to be secured to the lower structure 80 of the vehicle body 60 . The second longitudinal edge 24 of the safety net 20 comprises endpieces 110 . The endpieces 110 may be unitarily formed with the safety net 20 or attached in any conventional manner to the safety net 20 . However, it is recommended that the endpieces 110 be unitarily formed with the safety net 20 . In addition, the endpieces 110 are generally attached on the ends of the second longitudinal edge 24 to extend therefrom, and are generally perpendicular to the second longitudinal edge 24 .
Referring now to FIGS. 5 and 6, the endpieces 110 are utilized to attach the second longitudinal edge 24 to the lower structure 80 of the vehicle body 60 . A releasable hook 120 and a bolt 130 may be used for such purpose. More specifically, the releasable hook 120 is attached on exposed ends of the endpieces 110 , wherein the bolt 130 is engaged to the lower structure 80 . The exposed ends of the endpieces 110 may attach the releasable hook 120 in any manner, but sewing the exposed ends of the endpieces 110 to the releasable hook is preferred. In addition, a circular nut 132 and a cylindrical nut 134 may be placed between the bolt 130 and the lower structure 80 . The releasable hook 120 may engage a circular part 136 of the bolt 130 in order to secure the safety net 20 to the lower structure 80 . Moreover, it may be contemplated by those of ordinary skill in the art that a shoulder of the bolt 130 may also spread the loads over a wider area of the lower structure 80 and may further eliminate pulling out of the circular part 136 of the bolt 130 .
In the alternative, a releasable clip 140 may be utilized in place of the releasable hook 120 . The releasable clip 140 may be attached on the exposed ends of the endpieces 110 . The releasable clip 140 further comprises a movable clip piece 142 , wherein the clip piece 142 may be operated via a spring or the like. Like the releasable hook 120 , the clip 140 may engage the circular part 136 of the bolt 130 by the way of the movable clip piece 142 in order to secure the safety net 20 to the lower structure 80 .
It may be important to note that the safety net 20 of the present invention may be installed in the vehicle 10 prior to its sale in the marketplace, or retrofitted in the vehicle 10 after its purchase. In the case of the safety net 20 being already installed in the vehicle 10 prior to its exposure in the marketplace, manufacturers of such vehicle 10 would carry out the task of installation. In the alternative, the safety net 20 may be purchased separately and subsequently retrofitted to the vehicle 10 .
Additional modifications and improvements of the present invention may also be apparent to those of ordinary skill in the art. Thus, the particular combination of parts described and illustrated herein is intended to represent only certain embodiments of the present invention, and is not intended to serve as limitations of alternative devices within the spirit and scope of the invention.
|
A method of preventing at least one front seat of a vehicle from collapsing into a rear seat area during rear impact collisions with a vehicle occupant safety net thereby mitigating whiplash injuries to front seat occupants and reducing potential injuries to rear seat occupants. The method provides for positioning the vehicle occupant safety net between the at least one front seat and the rear seat area of the vehicle. The safety net is then secured to the vehicle. Moreover, the safety net is sized and configured to prevent the at least one front seat from collapsing rearwardly into the rear seat area during rear impact collisions thereof to mitigate whiplash injuries to the front seat occupants and reduce potential injuries to the rear seat occupants.
| 1
|
CROSS REFERENCE TO RELATED DISCLOSURE
A Disclosure Document dated Jun. 14, 1993, relating to the present invention was filed with the United States Patent and Trademark Office on Jun. 22, 1993 and recorded as Disclosure Document No. 333644. The content of this Disclosure Document is hereby incorporated by reference.
1. Field of the Invention
This invention relates to a dolly or hand truck converter hitch assembly, and method for its use, for converting a standard dolly into a trailer suitable for towing.
2. Background and Summary of the Invention
The familiar two-wheel hand truck or "dolly" has traditionally found application in a wide array of industrial and other commercial contexts. The standard dolly has further gained acceptance and found application domestically. The dolly or hand truck is useful, domestically, for a variety of projects including the movement of bulky items such as appliances and other household equipment as well as for the routine but awkward task of moving trash receptacles. While considerations relating to maximizing usable space and the storage of equipment are important in industrial and other commercial contexts, such considerations are perhaps more critical in the typical domestic context. For this reason, equipment which can be easily used for more than one purpose and conveniently stored is highly desirable. The present invention satisfies this need by providing a converter which transforms a standard dolly into a readily convertible dolly-trailer suitable for towing behind a vehicle which can be compactly stowed in an upright position either attached to or separated from the dolly-hand truck in a space virtually no greater than that required by the hand truck alone. The invention is adaptable for use such as by being connected to a lawn tractor or other vehicle and used as a hauling trailer. In the past, attempts have been made to expand the traditional scope of utility for hand trucks. For example, in U.S. Pat. No. 4,570,961 to Chateauneuf, et. al., a combination, dolly, wheelbarrow and shovel device is disclosed which relies upon a variety of interchangeable parts and telescoping side members for its versatility. Additionally, U.S. Pat. No. 4,921,270 to Schoberg, U.S. Pat. No. 3,679,225 to McKinney, U.S. Pat. No. 4,227,709 to Gradwohl, et. al. and U.S. Pat. No. 3,785,669 to Doheny each disclose standard two-wheeled hand trucks that convert for use as four-wheel carts in the nature of a wagon. Yet another device is disclosed in U.S. Pat. No. 5,028,060 to Martin which provides for a system of collapsing the handle and undercarriage components of a four-wheeled wagon in order to facilitate the storage and transportability of the wagon. Wheelbarrows have also been the subject of efforts to expand utility as, for example, in U.S. Pat. No. 5,087,061 to Wallace and U.S. Pat. No. 5,031,926 to Wannamaker. Wallace discloses a means for converting a wheelbarrow into a trailer by providing for foldable extension arms and a main frame tow bar that is permanently attached to the axle and undercarriage base rails. And, Wannamaker discloses a caster wheel and tongue assembly that attaches to the U-shaped, parallel frame aspects of a standard wheelbarrow in order to convert it for use as a trailer. Finally, U.S. Pat. No. 5,005,844 to Douglas, et. al. discloses a rolling travois comprising an enlarged roller assembly having a spherically shaped profile. The travois is attached for pulling behind an individual by way of a specially constructed harness worn by the individual.
The structure of each of these carriers, however, is dissimilar to the dolly conversion device of the present invention. Moreover, none of these prior art teachings provides a completely satisfactory conversion of a dolly to a trailer for towing behind a vehicle as disclosed herein.
The present invention comprises several new improvements in the dolly-hand truck art such that conversion from a conventional hand truck to a utility trailer and vice versa can be simply and efficiently accomplished. Significantly, the ease and efficiency with which the present invention can be used substantially eliminates the need for a separate trailer piece of equipment. No permanent modifications or fixtures need to be made or added to the hand truck. The converter hitch assembly is easily assembled from readily available and conveniently attached parts. The manner in which the converter connects to the hand truck makes use of existing structural features of the conventional hand truck and provides for a cooperating mechanical arrangement. Moreover, when the converter is not in use, the hand truck can be used exactly as it is customarily used.
The present hand truck-trailer comprises a conventional hand truck and a releasably attached converter hitch assembly. The conventional hand truck varies in size and configuration but commonly includes an elongate carriage frame forming a transverse or U-shaped handle at one end and terminating at the other end in a toe plate and a pair of wheels. Connecting the handle to the toe plate are longitudinal side members which are fixedly attached to transverse load-supporting cross-members.
The converter hitch assembly renders the dolly-hand truck suitable for towing behind a vehicle such as, for example, a riding lawn mower or forklift. It is generally T-shaped and includes a first member which, for example, can be an angle iron or other suitable member, and a second member, as for example, a pipe or bar with a suitable hitching adaptor at its distal end. The assembly further comprises a means for releasably attaching to the dolly-hand truck. Suitable means for releasable attachment of the first and second members include, for example, a plurality of collar fittings attached to the first and second members which clamp about the frame of the dolly-hand truck and lock thereabout by suitable fasteners. Alternatively, releasable attachment can be by a plurality of pre-bored metal plates attached to the first and second members and secured to the hand truck frame by suitable U-bolts and nuts. Additionally, the releasable attachment means can be by direct attachment of the first and second members to the hand truck by bolts and nuts, and/or a combination of the releasable attachment means herein discussed. Other, additional aspects and advantages of the present invention will become apparent when consideration is given to the balance of the specification contained herein.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a side elevational view of the preferred embodiment of the present invention with the unseen side being a mirror image;
FIG. 2 is a top plan view of the preferred embodiment of the present invention;
FIG. 3 is an enlarged front elevational view of the preferred embodiment of the present invention showing the collar fittings and locking pin fasteners;
FIG. 4 is an enlarged rear elevational view of the preferred embodiment; and
FIG. 5 is an enlarged bottom plan view of the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As seen in the drawings, in a preferred embodiment, the convertible hand truck trailer 10 of the present invention includes a conventional hand truck 12 and a releasably attachable hitching converter 14. The hand truck 12 has a structure well known in the art and comprises a U-shaped outer frame member 16 which has a pair of tubular, longitudinal legs 17 that bend at bends 18 into a transverse handle 19. The legs 17 are secured at their lower ends to a toe plate 20. A pair of wheels 22 are mounted to an axle 24 as known in the art. The frame member 16 is reinforced by a pair of tubular frame reinforcers 26, and parallel transverse supports 28 which are secured to a central longitudinal support 30.
The hitching converter 14 is generally T-shaped and includes a first transverse member comprising an angle iron 31. Angle iron 31 has a bottom flange 32 and an upright flange 34. The converter 14 further comprises a longitudinal second member 36 illustrated as a pipe. The proximal end of pipe 36 is secured, as by welding, to the upright flange 34.
The hitching converter 14 further comprises means for securing the angle iron 31 to the dolly frame legs 17, comprising a first pair of collar fittings 40 positioned near each end of the angle iron 31. Each fitting 40 comprises an upper eyelet 41 and lower U-shaped sides 42 which open downwardly for clamping about the dolly frame legs 17 (shown in phantom as 17(a) in FIG. 4). Each fitting 40 is secured by a nut 43 and a bolt 44 which pass through each eyelet 41 and through a bore in upright angle flange 34. The hitching converter 14 also comprises means for securing the pipe 30 to the transverse handle 19, comprising a second pair of collar fittings 45 identical to fittings 40, which are preferably welded or otherwise fixedly attached, as clearly shown in FIGS. 3 and 5 on either side of pipe 36. The U-shaped sides of fittings 45 depend downwardly to clamp about handle 19 (handle 19 is shown in phantom lines in FIG. 4). The fittings 40 and 45 are held about the legs 17 and handle 19 by pins 46 which pass through bores near the ends of the sides 42 of the fittings, and are secured against disengagement by U-shaped spring latches 47 which have one end that passes through a bore at one end of each pin 46, and another ringed end that can be pulled to fit around the opposite end of pin 46. See in particular the front (X) and side (Y) views in FIGS. 3 and 4.
When the converter 14 is mounted atop the hand truck 12, the underside of the angle iron flange 32 touches the top of legs 17, and the underside of pipe 36 touches the top, central region of handle 19.
A suitable hitching adaptor 48, as shown in FIGS. 1, 2 and 5, is forged into or otherwise fixedly attached to the distal end of pipe 36. The dimensions of both members of the T-shaped converter and related hardware specifications are defined based upon the specific configuration and size of the hand truck intended to be converted. This notwithstanding, the dimensions and specifications of the illustrated embodiment are as follows: the angle iron flange 34 is 2 inches wide, flange 32 is 3 inches wide and both flanges are 3/16 of an inch thick by 16 inches long; the pipe 36 is, typically, 1.5 inches in diameter and 19 inches long; and the collar fittings 40 and 45 are, typically, 3 inches in length. All of these components are preferably made of metal such as steel.
In the preferred embodiment, the converter 14 is attached to the hand truck 12 by first placing the hand truck 12 in a horizontal position as shown in FIG. 1, and placing the converter 14 on top of the hand truck 12 so that collar fittings 45 align intermediately with handle 19 and collar fittings 40 align with longitudinal frame legs 17. The converter 14 is then moved downward so that each of the fittings 40 and 45 are positioned as shown in the drawings to clamp about the handle 19 and frame legs 17. The pins 46 are then inserted and latched to the legs of the fittings as previously described. The trailer 10 is now ready for attachment by hitching adaptor 48 to a vehicle for towing. No special tools are required for this installation and removal of the device is easily accomplished by simply reversing the installation procedure.
Although FIGS. 1-5 show the preferred embodiment, the hitching converter can have a different structure. A conventional hand truck and generally T-shaped converter can be provided substantially as described above. However, instead of attaching to the hand truck by the collar fittings 40 and 45, a plurality of 2 inch wide by 4 inch long by 3/16 inch thick metal plates having pre-bored pilot holes drilled therethrough can be welded to the converter at the same locations as collar fittings 40 and 45 and in substitution therefor. This modified converter is similarly attached to the dolly by placing the converter on top of the dolly in a horizontal position with the pipe having the welded metal plates touching the transverse handle and having the metal plates welded to the angle iron upright flange touching the longitudinal legs of the dolly. When so positioned, U-bolts are inserted from the underside of the dolly through aligned pilot holes in each of the metal plates and secured by washers and nuts to the threaded ends of the U-bolts which protrude through the pilot holes in the welded metal plates.
Also, alternatively, the T-shaped converter, as previously described, without collar fittings or welded metal plates, can be provided wherein the converter is mounted directly to the hand truck by way of 1/2 inch machine bolts which pass through pre-bored pilot holes drilled intermediately through the pipe 36 and the corresponding central region of the handle 19 as well as through the angle iron bottom flange 32 and correspondingly through both of the legs 17.
Thus, the foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.
|
The compactly stowable and convertible hand truck-trailer of this invention comprises a T-shaped converter hitching assembly and a conventional hand truck which includes a carriage frame with legs supported by a pair of wheels at one end and having a transverse handle at the other end. The converter assembly releasably attaches through use of fittings to the legs and handle of the hand truck. The hitching assembly has a hitching adaptor that can be connected to a towing vehicle such as a lawn mower tractor.
| 1
|
FIELD OF THE INVENTION
The invention relates to fixtures for use in assembly lines.
BACKGROUND OF THE INVENTION
Industries that manufacture complex apparatuses or machinery, such as automobiles, motorcycles, engines, and the like, often use an assembly line to most efficiently assembly the apparatuses. These assembly lines often take up large amounts of space and create the need for a relatively large facility in which the apparatuses are assembled.
SUMMARY OF THE INVENTION
The present invention provides an assembly line fixture for use in assembling an apparatus (e.g., a motorcycle). The fixture includes an elevator having a mounting surface, and operable to raise and lower the mounting surface with respect to an assembly line floor. Mounted on the mounting surface is a turntable having a tabletop. The turntable rotates with respect to the mounting surface on a plurality of bearings that abut the underside of the tabletop.
A skirt depends from the tabletop, and substantially surrounds the periphery of the tabletop. The skirt includes a plurality of apertures spaced apart from each other at selected angular positions. A detent member engages the apertures to temporarily prevent the turntable from rotating with respect to the mounting surface. In this manner, the apparatus may be retained at a selected known angle of rotation with respect to the mounting surface while selected apparatus parts are installed or machined. An inner surface of the skirt includes a series of notches. A locking mechanism is provided that engages the notches in the skirt to firmly fix the turntable against rotation with respect to the mounting surface.
Mounted on a top surface of the tabletop is at least one clamp that is adapted to engage a portion of the apparatus (e.g., the frame of a motorcycle). A clamp-actuating mechanism is provided that causes the clamp to engage and disengage a portion of the apparatus. In one aspect of the invention, the clamp-actuating mechanism includes a shaft that is threadedly received in the clamp to move a portion of the clamp in reaction to rotation of the shaft. In another aspect of the invention, the clamp-actuating mechanism includes a cross-member that is pivoted by rotation of a lever to cause link members to open or close the clamp.
The fixture is easily moved along an assembly line on wheels or other means of transportation. The fixture takes up relatively little space in the assembly facility and is relatively easy to manipulate by an assembly line operator by way of foot peddles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of the fixture according to the present invention.
FIG. 2 is a top plan view of the fixture taken along line 2--2 in FIG. 1.
FIG. 3 is a top plan view of the fixture with some portions removed for the purpose of illustration.
FIG. 4 is a top plan view of the detent mechanism.
FIG. 5 is a side elevational view of the detent mechanism.
FIG. 6 is a side elevational view of the locking mechanism.
FIG. 7 is a side elevational view of a bearing.
FIG. 8 is a top plan view of a first clamp-actuating mechanism.
FIG. 9 is a side elevational view of the first clamp-actuating mechanism.
FIG. 10 is a cross-section view taken along line 10--10 in FIG. 8.
FIG. 11 is a top plan view of a second clamp-actuating mechanism.
FIG. 12 is a side elevational view of the second clamp-actuating mechanism.
FIG. 13 is a view taken along line 13--13 in FIG. 9.
FIG. 14 is a cross-section view taken along line 14--14 in FIG. 9
FIG. 15 is a cross-section view taken along line 15--15 in FIG. 9
DETAILED DESCRIPTION
FIG. 1 illustrates an assembly line fixture 10 supporting an apparatus 14 that has been assembled thereon. The illustrated apparatus is a motorcycle having a frame 18, a rear wheel 22, and a front wheel 26. The fixture 10 includes an elevator 30, which in the illustrated embodiment is either a pneumatic or an hydraulic scissor-leg table. The elevator 30 is mounted on a pallet or slab 34, which is supported by means for transporting the fixture 38, such as wheels. In this regard, the fixture 10 is movable along an assembly line floor 42.
The elevator 30 includes a platform 46, which is illustrated as being generally horizontally disposed, but which may also be disposed at an angle with respect to the assembly line floor 42. The platform 46 includes a top surface or a mounting surface 50 and a bottom surface 54. The elevator 30 is operable to raise and lower the platform 46 with respect to the assembly line floor 42. Foot peddles 58 (FIG. 2) are provided to facilitate operating the elevator 30.
The fixture 10 also includes a turntable 62 mounted on the mounting surface 50. The turntable 62 includes a tabletop 66 and a skirt 70 substantially surrounding the tabletop 66. Also mounted on the platform 46 are a detent mechanism 74, a locking mechanism 78, and a clamping mechanism 82.
With reference to FIGS. 3 and 7, the turntable 62 is supported for rotation about an axis of rotation 86 (extending perpendicular to the page in FIG. 3) by a plurality of bearings 90. The illustrated bearings 90 are mounted on the mounting surface 50 and engage the underside of the tabletop 66. A flange 94 defining a guide may be provided in the turntable 62 or on the mounting surface 50 to ensure the turntable 62 rotates substantially about the axis of rotation 86 on the bearings 90. The skirt 70 includes a number of apertures 98 at selected angular intervals (every 45° in the illustrated embodiment) around the skirt's circumference. The skirt 70 also includes a series of notches 102 along its inner surface. The skirt 70 may be provided as a piece that is separate from the tabletop 66, or may be formed integrally with the tabletop 66.
Referring now to FIGS. 4 and 5, the detent mechanism 74 operates to temporarily restrain the turntable 62 at selected angular positions. In the illustrated embodiment, the detent mechanism 74 includes a first biasing member 106, a two-piece shaft 110, and a roller 114. The roller 114 is biased against the outer surface of the skirt 70 of the turntable 62 by the first biasing member 106, which in the illustrated embodiment is a spring. The detent mechanism 74 also includes a swing arm 118 that maintains the roller 114 in proper alignment with the two-piece shaft 110 and the first biasing member 106. The swing arm 118 is pivotally mounted on the mounting surface 50.
In operation, as the turntable 62 is rotated, the roller 114 rolls along the outer surface of the skirt 70 until it encounters an aperture 98. Then the roller 114 is thrust into the aperture 98 by the biasing force of the first biasing member 106. The roller 114 thus received in the aperture 98 resists further rotation of the turntable 62. The roller 114 is disengaged from the aperture 98 by manually rotating the swing arm 118 to move the roller 114 away from the aperture 98, or by rotating the turntable 62 with sufficient force to cause the roller 114 to roll out of the aperture 98 against the biasing force of the first biasing member 106. In alternative embodiments of the invention, the detent mechanism 74 may be provided within in the skirt 70, and may include a roller 114 that operates on the inner surface of the skirt 70.
Referring now to FIGS. 3 and 6, the locking mechanism 78 includes a lever 122, a locking member 126, and a second biasing member 130. The locking member 126 is pivotally interconnected with a flange 134 mounted on the bottom surface of the platform 46, and is biased toward a locking position (illustrated in solid lines in FIG. 6) by way of the second biasing member 130. The illustrated second biasing member 130 is a spring and eye-bolt mounted to the bottom surface of the platform 46. The locking member 126 is received in one of the notches 102 when it is in the locking position, thereby preventing rotation of the turntable 62.
In the illustrated embodiment, the lever 122 is an over-center lever pivotal about a first pivot point 138 on the platform 46, and pivotal from an up position illustrated in solid lines (FIG. 6) to a down position illustrated in phantom. The over-center lever 122 is designed to remain locked in place when the lever 122 is moved into a down position shown in phantom in FIG. 6. A linkage, including a bent link 142 that is hingedly interconnected to the lever 122 at a second pivot point 146; a shaft 150, having a longitudinal axis, that is pivotally interconnected to the bent link 142, and which moves axially in reaction to rotation of the bent link 142; and an abutment member 154, operate to move the locking member 126 away from the skirt 70 when the lever 122 is in the down position. The shaft 150 is supported by a sleeve bearing to allow for axial movement of the shaft 150 in response to rotation of the lever 122. In the illustrated embodiment, the abutment member 154 is a fork having two prongs 158 that abut opposite side extensions of the locking member 126.
In operation, the lever 122 is moved to the down position to cause the locking member 126 to pivot out of engagement with the notches 102. Then the turntable 62 is rotated until the desired angular setting is achieved, at which time the lever 122 is rotated to the up position to allow the biased locking member 126 to engage the notch 102 with which it is aligned. The second biasing member 130 assists in returning the lever 122 to the up position when the lever 122 is rotated enough to place the second pivot point 146 just over the line of force defined by the longitudinal axis of the shaft 150.
The locking mechanism 78 may be used in conjunction with the detent mechanism 74 to quickly position the turntable 62 at a desired angular rotation (e.g., in increments of 45°) for installing or machining certain parts of the apparatus 14, and to lock the turntable 62 in that position while such installation or machining is carried out. Otherwise, the locking mechanism 78 may be used to lock the turntable 62 between the pre-set increments (e.g., every 45°).
The clamping mechanism 82 employing a first clamp-actuating mechanism 162 is illustrated in FIGS. 8-10. The illustrated clamping mechanism 82 includes a clamp 166 having a stationary member 170 and a movable member 174. The illustrated clamping mechanism 82 includes a pair of clamps 166. Both the stationary members 170 and the movable members 174 of each clamp 166 include abutment portions or jaws 178 that mirror the shape of a portion 182 of the apparatus 14 (e.g., a frame member of a motorcycle). When the movable members 174 are moved within slots 186 toward the stationary members 170, and into a clamping position illustrated in FIG. 9, the portion 182 of the apparatus 14 is snugly received between the abutment portions 178. The clamps 166 may also be moved into an opened position (FIG. 10) by moving the movable members 174 away from the stationary members 170. The portion 182 of the apparatus 14 is easily removed from the clamps 166 when the clamps 166 are in the opened position, but is firmly held in the clamps 166 when the clamps 166 are in the clamping position.
Referring to FIGS. 13-15, the clamps 166 are mounted on the platform 46 of the elevator 30 by way of fasteners 190, such as bolts. Various components of the clamps 166 are also interconnected with fasteners 194, such as bolts.
The first clamp-actuating mechanism 162 includes a screw member 198 that passes through the stationary members 170 and the movable members 174 of the clamps 166. The portion of the screw member 198 passing through the stationary members 170 is a smooth shaft that passes through the stationary members 170 for rotation with respect to the stationary members 170. The portion of the screw member 198 passing through the movable members 174 is threaded, and mates with threads in the movable members 174. The illustrated screw member 198 includes a head portion 202 to facilitate rotation of the screw member 198 with a tool 206, such as an air tool. When the screw member 198 is rotated by the tool 206, the movable members 174 are caused to move between the opened position and the clamping position depending on the direction the screw member 198 is rotated. Alternatively, the portion of the shaft passing through the stationary members 170 may have reverse threads, and the stationary members 170 may be allowed to move within slots. In that case, rotation of the screw member 198 would cause both of the clamp members 170, 174 to move toward or away from each other. In another alternative, the movable members 174 may be pivoted between the opened position and the closed position instead of sliding.
A clamping mechanism 82 incorporating a second clamp-actuating mechanism 210 is illustrated in FIGS. 11 and 12. This clamping mechanism 82 also includes a pair of clamps 166. However, each of the illustrated clamps 166 includes a pair of movable members 214. The illustrated movable members 214 are pivoted about generally horizontal axes of rotation, but the movable members 214 may also be movable in slots for translation parallel to the tabletop 66. The second clamp-actuating mechanism 210 includes a handle 218 and a lever bar 222. The lever bar 222 is interconnected with a cross-member 226 that is pivotally mounted at a pivot point 230. A pair of generally parallel link members 234 are pivotally interconnected with the cross-member 226. Each link member 234 is also pivotally interconnected with one of the movable members 214 of each of the clamps 166. When the lever 218 is pivoted in the direction shown by the arrow in FIG. 11, the cross-member 226 pivots about the pivot point 230, causing the link members 234 to move in opposite directions, and causing the clamps 166 to move toward an open position or a clamping position with respect to the portion 182 of the apparatus 14.
Thus, for example, a fixture 10 incorporating either the first or second clamp-actuating mechanism 162, 210 can be used to easily clamp onto a motorcycle frame at one end of an assembly line. As the frame moves along the assembly line, parts of the motorcycle are added to the frame, with assembly workers being able to raise and lower the elevator 30, and rotate the turntable 62 about the axis of rotation 86. At the end of the line, a motorcycle has been built on the fixture 10. The motorcycle is easily removed by opening the clamps 166 with the first or second clamp-actuating mechanism 162, 210.
Although particular embodiments of the present invention have been shown and described, other alternative embodiments will be apparent to those skilled in the art and are within the intended scope of the present invention. Thus, the present invention is to be limited only by the following claims.
|
An assembly line fixture includes an elevator having a mounting surface, and a turntable mounted on the mounting surface and rotatable about an axis of rotation with respect to the mounting surface. Also mounted on the mounting surface are a detent mechanism, a locking mechanism, and a clamping mechanism. The detent mechanism includes a roller that is spring biased against the turntable, and that is operable to resist rotation of the turntable at preselected angular positions. The locking mechanism includes a lever, a locking member, and a biasing member. The locking member engages notches in the turntable to prevent the turntable from rotating. The lever actuates the locking member and the biasing member biases the locking member toward the notches for engagement therewith. The clamping mechanism includes at least one clamp that is adapted to engage a portion of an apparatus. The clamping mechanism also includes a clamp-actuating mechanism that causes the clamp to close or open to respectively engage and disengage a portion of an apparatus.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/650,600 filed Feb. 7, 2005, which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to environmental sensors, and more particularly relates to sensors which utilize exponential growth of a signal initiated by interaction of a sensor element with characteristics of the environment.
BACKGROUND INFORMATION
Environmental sensors are used to detect various materials including chemical and biological agents. However, a need exists for improved sensors which can detect specific types of compounds and which can detect trace amounts of compounds.
SUMMARY OF THE INVENTION
This invention provides an environmental sensor system which is affected by environmental characteristics such as substances in the environment, the presence of electromagnetic radiation, and the like. The system includes a sensor element that is intrinsically sensitive or can be coated with a material that is sensitive to the specific environmental characteristic. The sensor may cause exponential growth of a system signal by parametric amplification. The quiescent operating point of the sensor is designed to be proximate to the threshold of onset or quenching of exponential growth.
The present invention represents an improvement over prior environmental sensors by utilizing exponential growth of a signal initiated by interaction of a sensor element with specific characteristics of the environment. The sensor system can have numerous embodiments, such as mechanical, electrical, magnetic or optical, as appropriate to the characteristic to be detected. Common features of these embodiments are the exponential growth of a sensor signal due to parametric amplification, and design of the quiescent operating point proximate to the threshold of onset or quenching of exponential growth.
In a physical system, one may distinguish dynamical variables, which usually change with changes in time, from material parameters, which usually are constant with changes in time. However, in any physical system, material parameters are constant only for sufficiently-small amplitudes of dynamical variation and for sufficiently-small changes in environmental parameters, such as temperature, external forces, incident radiation, or reaction with contiguous matter. When the amplitude of dynamical variation or the changes in environmental parameters are not sufficiently small, then the material parameters can have values which differ from those for small-amplitude dynamical variation. The parameters are then said to be nonlinear. A parametric amplifier is an amplifier utilizing a nonlinear material parameter or one that can be varied as a function of time by applying a suitable external influence known as a “pump”. An example is an electrical circuit consisting of a voltage generator, a resistor, a capacitor, and an inductor. The voltage and current in the circuit are dynamical variables; the resistance, capacitance, and inductance are parameters. If the capacitance is varied, for example, by mechanically varying the spacing of the capacitor electrodes (the “pump”), then parametric amplification of the voltage across the capacitor (the “signal”) can be produced.
The characteristic behavior of parametric amplification is the exponential growth of the amplitude of the signal when the amplitude of the pump exceeds some critical value. The exponential growth does not continue indefinitely, but eventually reaches saturation due to limitations of one or more components of the system. The gain factor, k, characterizing the growth of the signal is a function of material and dynamical quantities. When certain conditions are satisfied and the amplitude of the pump is such that k exceeds its critical value, then exponential growth of the signal is initiated. Features of this invention are the exponential growth of the signal during the time interval between threshold and saturation, and the dependence of the growth factor, k, on environmentally-sensitive quantities. Various embodiments of the parametric-amplifier system can be constructed according to these principles.
An aspect of the present invention is to provide a parametric amplification system comprising a dither transducer, a pump transducer, and an elastic rod connected between the dither and pump transducers.
Another aspect of the present invention is to provide an environmental sensor including a parametric amplifier which exhibits exponential temporal growth when exposed to an environmental characteristic.
A further aspect of the present invention is to provide a method of detecting an environmental characteristic. The method comprises exposing a sensor to an environment, and monitoring exponential temporal growth of a signal generated by the sensor upon exposure to the environmental characteristic.
These and other aspects of the present invention will be more apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a system used to produce parametric amplification in an elastic rod in accordance with an embodiment of the present invention.
FIG. 2 is a block diagram of an apparatus for exciting and measuring parametric amplification in an elastic rod in accordance with an embodiment of the present invention.
FIG. 3 is a graph of measured displacement at frequency 1 f as a function of time for bending motion in an elastic rod with the pump voltage at a frequency of 2f turned on at t=50 ms.
FIG. 4 shows growth of amplitude, G(t), of a bending motion at f=1.7 kHz as computed from a numerical solution of Eq. (4).
FIG. 5 shows variation of doubling time with attenuation near the critical point for parametric amplification in a rod vibrating in bending.
FIG. 6 is a block diagram of apparatus for laser switching of parametric amplification in a rod in accordance with an embodiment of the present invention.
FIG. 7 is a graph of photodetector voltage vs. time showing laser quenching of parametric amplification in a rod vibrating in bending.
FIG. 8 is a schematic diagram for a generator with EMF, E, connected in series with resistance, R, capacitance, C, and inductance, L.
FIG. 9 shows parametric amplifier gain, k, as a function of pump amplitude, a, for a series RLC circuit with variable capacitance.
FIG. 10 shows voltage across a capacitor as a function of time for parametric amplification due to variable capacitance for E=1 V, a=0.05, C 0 =35.9 pF, L=706 μH, f 0 =1 MHz, and R=50Ω.
FIG. 11 is a schematic diagram for a generator with EMF, E, and resistance, R g , connected to a parallel RLC network.
FIG. 12 shows voltage across a parallel network as a function of time for parametric amplification due to variable inductance for E=1 V, R g =1 kΩ, a=0.33, C 0 =50 pF, L 0 =1 μH, f 0 =22.5 MHz, and R=1 MΩ.
FIG. 13 shows voltage across a lossy capacitor for parametric amplification due to variable inductance for E=1 V, R g =50Ω, a=0.84, C 0 =50 pF, L 0 =1 μH, f 0 =22.5 MHz, and R=1 MΩ.
DETAILED DESCRIPTION
An embodiment of the invention provides an environmental sensor which utilizes parametric amplification of bending motion in an elastic rod. An example of such an assembly 10 is illustrated in FIG. 1 . The ends of an elastic rod 24 made of a material such as fused quartz, Teflon or Nitinol are attached to electro-mechanical transducers in the form of a dither transducer 20 and a pump transducer 22 . The size of the elastic rod 24 may be selected based upon the desired frequency of operation, for example, having a diameter of from less than 1 to greater than 10 or 100 mm, and a length of from less than 10 to greater than 100 mm. The dither transducer 20 may be a piezoelectric tube configured to bend perpendicular to its axis upon the application of voltage to its electrodes. The piezoelectric material of the dither transducer 20 may comprise lead-zirconium-titanate or any other suitable material, and the size of the tube may be selected based upon the desired frequency of operation, for example, having a diameter of from 1 or 2 to greater than 10 or 100 mm, and a length of from less than 10 to greater than 100 mm. The pump transducer 22 may be a piezoelectric tube configured to extend parallel to its axis upon the application of voltage to its electrodes. The piezoelectric material of the pump transducer 22 may comprise lead-zirconium-titanate or any other suitable material, and the size of the tube may be selected based upon the desired frequency of operation, for example, having a diameter of from 1 or 2 to greater than 10 or 100 mm, and a length of from less than 10 to greater than 100 mm. The transducers 20 and 22 are affixed to mounting plates 16 and 18 , respectively, which are in turn affixed to brackets 14 . The assembly is affixed to a base plate 12 .
The electrical components for exciting the transducers and the instrumentation for measuring the bending motion are illustrated in FIG. 2 . An AC voltage with frequency, f, from a signal generator is connected to the dither transducer 20 . The output of the signal generator is also connected to a frequency multiplier. The output of the frequency multiplier with frequency, 2 f , is connected to a voltage amplifier. The amplified voltage is connected to the pump transducer 22 .
In operation, the frequency, f, of the generator signal is adjusted to correspond to a bending resonance (its fundamental resonance, for example) of the elastic rod 24 . The amplitude is set at a convenient value. The amplitude of the longitudinal vibration (2 f ) of the pump transducer 22 is then increased from zero up to the critical value required for parametric amplification of the bending motion of the elastic rod 24 at frequency, f. When the pump amplitude is above the threshold value, the bending motion increases exponentially with time until the motion saturates.
The parametric amplification of the bending signal can be measured using the detection apparatus also shown in FIG. 2 . The signal generator, frequency multiplier, and oscilloscope are controlled via a general-purpose interface bus (GPIB) by the computer. With the frequency of the signal generator tuned to a bending resonance of the rod, the frequency-multiplier is gated on, and the displacement from equilibrium is recorded as a function of time using the waveform-digitizing oscilloscope. A beam from a laser is focused on the rod 24 and a photodetector detects the light scattered by the rod 24 . The effect of the motion of the rod 24 in the focal plane of the laser beam on the photodetector signal can be calibrated. The bending motion of the rod 24 can then be measured using a method known as optical-beam-deflection (OBD) sensing.
An example of the temporal development of the bending motion of the rod is shown in FIG. 3 . The pump voltage at a frequency twice that of the signal frequency was turned on at about t=150 ms. Also shown is a fit of an exponential function to the data. A good fit with a time constant of 62 ms is obtained until saturation begins.
A theoretical model of parametric amplification in elastic rods was developed so that environmental sensors could be quantitatively designed. The model is an elastic rod with (Young's) modulus of elasticity, E, density, ρ, radius, R, and length, L. The equation of motion of a rod in bending with losses (G. C. Wetsel, Jr. and M. A. Drummond Roby, “Dynamic Nanoscale Lateral-Force Determination”, Appl. Phys. Lett. 67, 2735-2737 (1995)) is
∂ 2 u ∂ t 2 + E ρ K 0 2 ∂ 4 ∂ z 4 [ u + α ∂ u ∂ t ] = 0 ( 1 )
where u is the transverse displacement from equilibrium of a point, z, on the rod at time, t, K 0 is the radius of gyration (K 0 =R/2 for a cylindrical rod of radius, R), and α is the parameter representing energy lost (the attenuation factor) from the vibration. For purposes of describing the results of the parametric amplification experiment, it was assumed that Eq. (1) is valid with the modification that Young's modulus is a function of time of the form,
E ( t )= E 0 (1+α sin ω p t ) (2)
where a=δE 0 /E 0 . The variables can be separated with the assumption, u(z,t)=U(z)G(t), to obtain a linear, fourth-order differential equation for U(z),
ⅆ 4 U ⅆ z 4 = K 4 U , ( 3 )
where K 4 =(ω 2 ρ)/(E 0 K 0 2 ) and a nonlinear second-order differential equation for G(t),
ⅆ 2 G ⅆ t 2 = - ω 2 ( 1 + a sin ω p t ) ( α ⅆ G ⅆ t + G ) ( 4 )
where ω 2 is the separation constant. The solution of Eq. (3) is well-known (e.g., G. C. Wetsel, Jr. and M. A. Drummond Roby, “Dynamic Nanoscale Lateral-Force Determination”, Appl. Phys. Lett. 67, 2735-2737 (1995)). The specific nature of the solution to Eq. (3) depends on the boundary conditions; the boundary conditions appropriate to this problem are that the rod is clamped at z=0 and z=L. For this case, the normal-mode resonant frequencies are given by
f ( n ) = v L K 0 β 2 ( n ) 2 π L 2 ( 5 )
where v L =(E/ρ) 1/2 , and β(n) depends on the specific normal mode. For the fundamental mode of vibration, β(1)=4.73004074486. As an example, for a rod 0.1395 mm in radius and 20.75 mm long fabricated from Nitinol, the fundamental resonant frequency is 1724 Hz.
Solution of the temporal equation yields parametric amplification. An approximate, analytical solution to Eq. (4) of the form,
G ( t )= g ( t ) e j(ωt+φ) +c.c. (6)
reveals that g=g 0 exp(kt), ω=ω p /2, and φ=0,2π, . . . so that
G ( t )= g 0 e kt e jω ρ t/2 +c.c.=e kt cos(ω p t /2) (7)
where the amplitude of u is subsumed in U(z), and
k = ω [ a - 2 αω 4 - a αω ] ( 8 )
There is exponential growth if k>0, which occurs if 2αω<a<4/(αω). For example, if f=1700 Hz α=5×10 −7 s, then 1.068×10 −2 <a<749.
Equation (4) was also numerically integrated using a computer. The essential features of the analytical solution were verified. An example of the exponential growth of G(t) is shown in FIG. 4 . Calculations based on the theoretical model are in good agreement with the experimental results.
Design of an environmental sensor utilizing parametric amplification of a rod in bending is based on Eq. (8). The exponential-growth factor, k, is an explicit function of dynamic and material parameters: k=k(ω, a, α). Since the device is operated at a bending resonant frequency, k is also an implicit function of the material parameters, ρ, E 0 , R, and L. When the pump is off (a=0), then the bending motion decays to zero from an initial value at a rate determined by the value of α. When the pump is turned on at a frequency equal to twice the resonant frequency of the bending mode, then the strength of the pump, a, competes with the energy-loss factor, α, to determine whether exponential decay or exponential growth occurs. For fixed α and variable a, then the critical value of pump strength, a c =2αω=4παf, must be exceeded in order for parametric amplification to occur. For fixed a and variable α, then extant parametric amplification will be quenched when the attenuation factor exceeds the critical value, α c =a/(4πf). Whereas the energy-loss parameter, α, is of direct and obvious importance in this embodiment, the other material parameters can also play an important role.
Practical applications of environmental sensing include the detection of environmental characteristics, such as toxins, which might make sudden appearances in trace amounts. Therefore, an important feature of environmental sensors is sensitivity. One measure of sensitivity to changes in α in this embodiment is the time, t 2 , required for the amplitude of bending motion to double. The doubling time is related to gain by t 2 =ln(2)/k. For example, if f=1700 Hz, α=6.336×10 −7 s, and a=0.0137, then k=0.4393 s −1 and t 2 =1.578 s; if f=1700 Hz α=6.4×10 −7 s, and a=0.0137, then k=0.0742 s −1 and t 2 =9.34 s. That is, a 1% change in αresults in a 492% change in t 2 in this example.
FIG. 5 shows a plot of log(t 2 ) vs. log(α); t 2 is essentially equal to 4 ln2/(αω) for small values of α, but increases rapidly with α as α→α c . The quiescent operating point of the sensor should be near the critical point; then the sensor will be optimally-responsive to environmental changes. Changes in other material parameters could be utilized in a similar manner as dictated by the environmental characteristic to be sensed.
One method of utilizing the sensitivity of bending motion of the rod to its environment is to make use of effects induced by electromagnetic radiation. In many substances, incident electromagnetic radiation is absorbed and rapidly converted into heat. This photothermal conversion produces thermal changes in material parameters and also induces motion in the material via thermoacoustic coupling (e.g., F. A. McDonald and G. C. Wetsel, Jr., “Theory of Photoacoustic and Photothermal Effects in Condensed Matter”, pp. 167-277 , Physical Acoustics , Vol. 18, W. P. Mason and R. N. Thurston, Eds., Academic Press, San Diego, Calif. (1988)). The intrinsic rod material or a coating applied to the rod could be chosen to be particularly susceptible to radiation of a particular wavelength and an affinity for a particular substance in the environment (e.g., biotoxins). Then, when interactions of that material with environmental substances shift the absorption wavelengths, photothermal conversion would be modified and hence its affect on the environmental sensor would be modified.
An example of the interaction of a parametric-amplification device with its environment is the toggling of the amplification off and on using photothermal heating by a laser. A system of controlled deflection of the laser beam to quench parametric amplification in the present embodiment is shown in FIG. 6 . The light from the OBD laser is scattered by the rod 24 and detected by the photodetector. The rod 24 is driven at a bending resonance with frequency, f, by the dither transducer 20 . The rod's modulus of elasticity is varied at 2f by the pump transducer 22 . Light from a heating laser passes through an acousto-optic (AO) modulator and iris and is reflected by a mirror toward the rod 24 . Parametric amplification is established by increasing the pump signal until the OBD (1f) signal is saturated. When the AO modulator is gated, the beam from the heating laser illuminates the rod 24 . The parametric amplification is then quenched. FIG. 7 shows the envelope of the OBD signal as captured on a waveform-digitizing oscilloscope. The parametric amplification can be repeatedly switched off and on by deflecting the heating laser beam on and off the rod.
In addition to the embodiment described above, alternate embodiments that incorporate exponential growth due to parametric amplification and sensitivity to environmental characteristics may be used. One such embodiment is an electrical network such as that shown in FIG. 8 . A resistor with resistance, R, a capacitor with capacitance, C, and an inductor with inductance, L, are connected in series with an AC generator with EMF, E, and frequency, f, tuned to the resonant frequency, f 0 , of the circuit. If the capacitance is varied, e.g., by varying the spacing, d, of the electrodes with an electromechanical transducer,
d ( t )= d 0 (1+α sin ω p t ) (9)
then an analysis similar to the one above shows that the voltage, v c , across the capacitor varies exponentially with time when ω=ω p /2, and φ=0,2,π, . . . The exponential factor is
k
=
ω
0
2
a
2
ω
p
-
α
2
,
α
=
R
/
L
.
(
10
)
If k>0, there is exponential gain; k=0 corresponds to constant amplitude. The critical value of a for exponential gain is
α c =RC 0 ω p . (11)
FIG. 9 shows k vs. a for representative values of the parameters. If f p /2=f 0 =1 MHz, then a c =0.02255. The circuit equation was solved numerically and v c (t) was computed. A plot is shown in FIG. 10 for typical values of the parameters. For operation on resonance ω=ω 0 =1/(L/C 0 ) 1/2 , and
k = a 4 LC 0 - R 2 L , ( 12 )
where C 0 is a function of the dielectric permittivity, ∈.
Design of an environmental sensor utilizing parametric amplification due to a variable capacitance in an RLC circuit may be based on Eq. (12). When the pump is off (a=0), then v c decays to zero from an initial value at a rate determined by the value of R/(2L). When the pump is turned on at a frequency equal to twice the resonant frequency of the circuit, then the strength of the pump, a, competes with energy-loss to determine whether exponential decay or exponential growth occurs as in the previous embodiment. One method of designing a sensor in this embodiment is to make use of the sensitivity of the dielectric permittivity, ∈, to changes in environmental characteristics. The dielectric could be fabricated from a material designed to be particularly sensitive to the environmental characteristic of interest. For example, the dielectric material could be a polymer, such as FEP, that has been infused with or coated with a substance appropriate to the design requirements of the sensor. Polymer dielectrics infused with a specific metal are particularly useful for this purpose. The gain factor, k, is also a function of circuit resistance. It is recognized that since dielectrics have energy losses in time-varying electric fields, environmental effects on the losses—the parallel resistance in an equivalent circuit for a lossy capacitor—can also be effectively utilized in parametric-amplifier based sensors.
An alternative embodiment is a parallel RLC network illustrated in FIG. 11 , where the inductance is varied. An AC generator with EMF, E, and resistance, R g , represented by the resistor, is connected to the parallel network consisting of an inductor with inductance, L, a capacitor with capacitance, C, and a resistor with resistance, R. The circuit equation for the voltage, v, across the parallel network was solved numerically for L=L 0 [1+a sin(ω p t +φ)]. An example of parametric amplification at ω=ω p /2 is shown in FIG. 12 for E=1 V, R g =50Ω, a=0.33, R=1 MΩ, L 0 =1 μH, and C=0.5 pF, f=22.5 MHz, and a=0.33.
Yet another embodiment is provided by an AC generator with EMF, E, and resistance, R g , connected in series with an inductance, L, and a lossy capacitor with capacitance, C, and parallel resistance, R. The circuit equation for the voltage, v c , across the lossy capacitor was solved numerically for L=L 0 [1+a sin(ω p t+φ)]. An example of parametric amplification at ω=ω p /3 is shown in FIG. 13 for E=1 V, R g =50 Ω, R=1 MΩ, L 0 =1 μH, C=0.5 pF, f=22.5 MHz, and a=0.84.
In accordance with the present invention, networks using variable inductance can be adapted to sense environmental characteristics. Coupling to the environment could occur through the magnetic permeability, μ, of the inductor. For example, if the inductor core material is a rare-earth magnet, such as an Nd—Fe—B alloy, then its magnetization is affected by temperature, chemically-aggressive media such as acids, and harmful gases such as hydrogen. Whereas these magnets often have protective coatings to preserve the magnetization, the coatings could be modified so that exposure to an aggressor would cause a change in the inductance, which would in turn modify the exponential growth of the parametric amplification. For example, a sensitive hydrogen detector could be designed based on parametric amplification in a variable-inductance RLC network.
In accordance with a further embodiment of the present invention, electromagnetic waveguides using variable parameters such as transverse dimensions can be adapted to sense environmental characteristics. For example, the capacitance of a transverse-electromagnetic transmission line may be varied by changing the spacing between the conductors guiding the wave. Access to the dielectric by substances in the environment may occur through a conducting wire mesh serving as one electrode. For example, in the case of RG-58 coaxial cable, a change in capacitance of the order of 2% at a signal frequency of 100 MHz would lead to exponential growth of the sensor signal.
Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.
|
A system for sensing characteristics of the environment is disclosed. Sensors utilize exponential growth of a signal initiated by interaction of a sensor element with characteristics of the environment. Specific substances in the environment can be detected. The sensor element may be intrinsically sensitive to the specific substance or can be coated with a material that is sensitive to the specific substance. The sensor component is designed such that it can be made to cause exponential growth of a system signal. The exponential growth of the sensor signal is produced by parametric amplification.
| 7
|
CLAIM FOR PRIORITY
This application claims the benefit of priority to German Application No. 103 24 502.2, filed in the German language on May 26, 2003, the contents of which are hereby incorporated by reference.
TECHNICAL FIELD OF THE INVENTION
The invention relates to a mask, in particular a photomask, for producing semiconductor devices, and to a method for producing semiconductor devices by means of such type of mask.
BACKGROUND OF THE INVENTION
For producing semiconductor devices, in particular silicon semiconductor devices, so-called photolithographic methods may, for instance, be used.
With these methods, the surface of a corresponding wafer—consisting of monocrystalline silicon—is subject to an oxidation process, and subsequently a light-sensitive photoresist layer is applied to the oxide layer.
Subsequently—by interconnecting an appropriate optical device—a photomask is placed above the wafer, the layout structure of which corresponds to the layout structure to be provided on the wafer—or a particular level of the wafer.
Then, the photomask—and thus also the corresponding structure on the photoresist—is exposed, and then the photomask is removed again.
When the photoresist is then developed and subject to an etching process, the exposed positions of the photoresist (and the respective positions of the oxide layer thereunder) are removed from the wafer—and the non-exposed positions are left (or—in the case of negative photoresist—in a correspondingly opposite manner the exposed positions).
Through the exposed windows, the monocrystalline silicon can now specifically be supplied with impurities, e.g. by corresponding diffusion or ion implantation processes; n-conductive regions may, for instance, be produced by the introduction of pentavalent atoms, e.g. phosphorus, and p-conductive regions may be produced by the introduction of trivalent atoms, e.g. boron.
The structures that can be put into practice by means of such photolithographic methods may range within the wavelengths of the light used for exposure.
Conventionally, for each level of the wafer (or for each level of the semiconductor devices or chips to be produced thereon, respectively) respective separate masks with respective different layout structures are used.
For the production of different chips, different mask sets have to be used.
If the chip layout is to be changed for a particular chip, new masks are needed (in particular e.g. a complete, new mask set).
This is of disadvantage especially since the production of masks is costly and expensive.
SUMMARY OF THE INVENTION
The invention provides a novel mask, in particular a photomask, for the production of semiconductor devices, and a novel method for the production of semiconductor devices.
In accordance with one embodiment of the invention, a mask, in particular a photomask, is provided for the production of semiconductor devices, wherein a region—assigned to at least two, and preferably all, semiconductor devices to be produced side by side on a wafer and to be exposed by means of the mask, or, in particular, the entire array or product field region of the mask, is provided completely with a layout structure, in particular with cell structures.
During the exposure of the wafer, partial regions of the mask—that are not required—can be faded out, in particular cell structures that are not required.
The above-mentioned photomask has—vis-à-vis conventional photomasks—i.e., the advantage of a substantially more homogeneous structure.
When the photomask has a defect at a particular position (which is exposed with a standard orientation of the photomask with respect to the wafer), the defect may, by appropriate shifting of the photomask, be shifted to a region that is faded out during exposure.
The above-mentioned photomask may—this is a special advantage—be used for exposing a plurality of different levels—that have, in particular, an identical cell structure—of one and the same wafer.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention will be explained in detail with reference to the embodiments and drawings. The drawings show:
FIG. 1 shows a top view of a conventional photomask;
FIG. 2 shows a top view of a photomask according to an embodiment of the present invention.
FIG. 3 shows a top view of a further photomask that is used—together with the photomask illustrated in FIG. 2 —for exposure of an individual level or layer of a wafer (or the semiconductor devices or chips to be produced thereon, respectively).
FIG. 4 shows a view of an aperture device used additionally with the exposure of a wafer by using the photomask illustrated in FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic top view of a conventional photomask 1 . The photomask 1 comprises a substrate layer—which is, in FIG. 1 , positioned at the bottom—e.g. a quartz layer (or e.g. a crown glass layer, a borosilicate glass layer, etc.), and a masking layer positioned above the substrate or quartz layer, respectively, e.g. a chromium layer (or e.g. an iron oxide layer, etc.).
During the production of the photomask 1 , the (top) masking layer, in particular chromium layer, is provided with a layout structure corresponding to the layout structure to be produced later on an appropriate wafer (or a particular level of the wafer, respectively), wherein—by means of an etching process, preferably a plasma etching process, the masking layer, preferably chromium layer, is completely removed at the corresponding positions (cf. e.g. the structure lines 4 a , 4 b , 4 c , 4 d , 4 e , 4 f illustrated (merely schematically) in FIG. 1 and positioned between chromium positions that have been left.
As is illustrated in FIG. 1 , the photomask 1 is divided into a plurality of substantially identical, rectangular regions 5 a, 5 b, 5 c, 5 d, 5 e, 5 f, 5 g, 5 h that are each provided with the same layout structure and are arranged array-like side by side in rows 2 a, 2 b, 2 c, 2 d, 2 e, 2 f and columns 3 a, 3 b, 3 c, 3 d, 3 e (and forming together an array region 9 ) (In FIG. 1 , the photomask regions positioned in rows 2 b, 2 c, 2 d, and 2 e and in the columns 3 a, 3 b, 3 c 3 d and 3 e corresponding to the photomask regions 5 a, 5 b, 5 c, 5 d, 5 e, 5 f, 5 g, and 5 h are illustrated, remaining photomask regions are partially illustrated by means of appropriate dots).
Each of the above-mentioned photomask regions 5 a , 5 b , 5 c , 5 d , 5 e , 5 f , 5 g , 5 h is used for the exposure of a particular, individual semiconductor device or chip to be produced on the wafer.
The semiconductor devices may, for instance, be appropriate logic and/or memory devices, e.g. ROM or RAM memory devices, in particular DRAMs.
Central regions 6 a , 6 b , 6 c , 6 d , 6 e , 6 f , 6 g , 6 h that are substantially identical, rectangular, and each have the same layout structure (here the above-mentioned structure lines 4 a , 4 b , 4 c , 4 d , 4 e , 4 f ) are each positioned centrally in the corresponding photomask regions 5 a , 5 b , 5 c , 5 d , 5 e , 5 f , 5 g , 5 h.
These may serve, for instance—with particular, individual memory devices to be produced on the wafer—for the exposure of regions on which the—actual—memory device memory cells are produced (“cell regions” 6 a , 6 b , 6 c , 6 d , 6 e , 6 f , 6 g , 6 h ).
The structure lines 4 a , 4 b , 3 c , 4 d , 4 e , 4 f positioned in the corresponding “cell regions” 6 a , 6 b , 6 c , 6 d , 6 e , 6 f , 6 g , 6 h and illustrated in FIG. 1 may, for instance, be substantially parallel to one another and may, for instance, each have a width and/or a mutual distance of e.g. approx. 30 nm-600 nm, in particular 50 nm-250 nm (wherein the width or the mutual distance of the structure lines 4 a , 4 b , 4 c , 4 d , 4 e , 4 f may—depending on the optical device that is later on connected between a corresponding wafer and the photomask 1 —e.g. correspond (with 1:1 photomasks) to the breadth and/or the mutual distance of circuit paths to be produced —later on—on the wafer by means of the photomask 1 , or (with 4:1 photomasks) e.g. to a four-fold thereof, etc., etc.
As is further illustrated in FIG. 1 , around the central regions (“cell regions”) 6 a , 6 b , 6 c , 6 d , 6 e , 6 f , 6 g , 6 h —and likewise in the above-mentioned photomask regions 5 a , 5 b , 5 c , 5 d , 5 e , 5 f , 5 g , 5 h (used for the exposure of particular, individual semiconductor devices)— there are positioned substantially identical, frame-shaped, regions 7 a , 7 b , 7 c , 7 d , 7 e , 7 f , 7 g , 7 h that are also provided with the same layout structure each.
These may, for instance, serve for the exposure of regions on the wafer on which the structures surrounding the—actual—memory device memory cells, possibly connected thereto, are produced (e.g. corresponding (connecting or pad) logic devices, (connecting) lines, spines, kerfs, etc. serving for connection of the memory cells to the outside) (“non-cell regions” 7 a , 7 b , 7 c , 7 d , 7 e , 7 f , 7 g , 7 h ).
In accordance with FIG. 1 , the above-mentioned photomask regions 5 a , 5 b , 5 c , 5 d , 5 e , 5 f , 5 g , 5 h —used for the exposure of particular, individual semiconductor devices—may be arranged in each row 2 a , 2 b , 2 c , 2 d , 2 e , 2 f and column 3 a , 3 b , 3 c , 3 d , 3 e in vertical and horizontal direction each with certain—equidistant—distances a, b from one another. The regions of the photomask 1 positioned (directly) between the regions 5 a , 5 b , 5 c , 5 d , 5 e , 5 f , 5 g , 5 h (and resulting from the distances a, b of the regions 5 a , 5 b , 5 c , 5 d , 5 e , 5 f , 5 g , 5 h from one another) are not used for the exposure of layout structures of the semiconductor devices to be produced on the wafer (but are each assigned to regions on the wafer positioned between the semiconductor devices to be produced and are therefore completely or substantially completely covered with the above-mentioned masking layer, in particular chromium layer).
The conventional photomask 1 illustrated in FIG. 1 is used for the exposure of a particular level or layer, respectively, of the wafer (or the semiconductor devices or chips to be produced thereon, respectively).
For the exposure of the remaining levels or layers (positioned above or below the above-mentioned level or layer) of the semiconductor devices or chips to be produced, further photomasks—that are, in general, in a correspondingly similar way to the photomask 1 illustrated in FIG. 1 , divided correspondingly into cell and non-cell regions—with respectively different layout structures are used (e.g. 10 to 40 (in particular 20 to 30) different photomasks for the exposure of 10 to 40 (in particular 20 to 30) different chip levels). For each level of the wafer (or for each level of the semiconductor devices or chips to be produced thereon, respectively) respectively separate photomasks with respectively different layout structures are thus conventionally used.
FIG. 2 shows a schematic view of a photomask 11 in accordance with an embodiment of the present invention.
The photomask 11 serves for the exposure of several semiconductor devices or chips to be produced in corresponding rows and columns side by side on one and the same wafer (or alternatively e.g. only for the exposure of one individual semiconductor device).
The semiconductor devices (or the individual semiconductor device) may, for instance, be (a) corresponding logic and/or memory device(s), e.g. (a) ROM or RAM memory device(s), in particular (a) DRAM(s).
The photomask 11 comprises a substrate layer, e.g. a quartz layer (or e.g. a crown glass layer, a borosilicate glass layer, etc)—positioned, in the drawing according to FIG. 2 , at the bottom —, and a masking layer, e.g. a chromium layer (or e.g. an iron oxide layer, etc.) positioned above the substrate or quartz layer, respectively.
During the production of the photomask 11 , the (top) masking layer, in particular chromium layer, is provided with a specific layout structure 18 that will still be explained in more detail in the following, wherein—by means of an etching process, preferably a plasma etching process—the masking layer, preferably chromium layer, is completely removed at the corresponding positions (cf. e.g. the structure lines 14 a , 14 b , 14 c , 14 d , 14 e , 14 f (illustrated merely schematically here) of the layout structure 18 positioned between chromium positions that have been left as illustrated in FIG. 1 ).
As results from FIG. 2 , the layout structure 18 (here: its structure lines 14 a , 14 b , 14 c , 14 d , 14 e , 14 f ) does not only extend over the respective regions or partial regions used for the exposure of an individual semiconductor device or chip to be produced on the corresponding wafer (corresponding approximately to regions 5 a , 5 b , 5 c , 5 d , 5 e , 5 f , 5 g , 5 h with the photomask 1 illustrated in FIG. 1 , or partial regions thereof, e.g. corresponding cell or non-cell regions 6 a , 6 b , 6 c , 6 d , 6 e , 6 f , 6 g , 6 h , 7 a , 7 b , 7 c , 7 d , 7 e , 7 f , 7 g , 7 h ), but over the entire array region 19 or product field region of the photomask 11 (or here: over a—circular—region corresponding to the entire wafer to be exposed, or a (somewhat) exceeding—e.g. rectangular—region)—apart e.g. from a mask edge region 12 in which e.g. a compensation structure and/or an alignment structure and/or a barcode structure and/or a PCM (Process Control Monitor) structure and/or a structureless frame region, etc. may be provided.
With alternative embodiments that are not illustrated here, the layout structure may also extend over the entire or substantially the entire region of the photomask 11 (i.e.—other than with the photomask 11 illustrated in FIG. 2 —also or partially also over the photomask edge region 12 ).
The layout structure 18 (here: each of the structure lines 14 a , 14 b , 14 c , 14 d , 14 e , 14 f that are extending continuously in one piece) in particular also extends over regions positioned between the actual regions used for the exposure of the semiconductor devices or chips to be produced on the wafer (e.g. over regions positioned (directly) between regions that correspond to the regions 5 a , 5 b , 5 c , 5 d , 5 e , 5 f , 5 g , 5 h with the photomask 1 illustrated in FIG. 1 , or over regions positioned between regions that correspond to the cell and non-cell regions 6 a , 6 b , 6 c , 6 d , 6 e , 6 f , 6 g , 6 h , 7 a , 7 b , 7 c , 7 d , 7 e , 7 f , 7 g , 7 h with the photomask 1 illustrated in FIG. 1 ).
The structure lines 14 a , 14 b , 14 c , 14 d , 14 e , 14 f of the layout structure 18 illustrated in FIG. 2 may e.g. be positioned substantially parallel to one another and may, for instance, each have a width and/or a mutual distance of e.g. approx. 30 nm-600 nm, in particular 50 nm-250 nm (wherein the width or the mutual line distance may—depending on the optical device connected later on between a corresponding wafer and the photomask 11 —e.g. correspond (with 1:1 photomasks) to the breadth and/or the mutual distance of circuit paths to be produced—later on—on the wafer by means of the photomask 11 , or (with 4:1 photomasks) e.g. to a four-fold thereof, etc., etc.
When an alternating phase mask is used as photomask 11 , the substrate layer, preferably a quartz layer, is etched away down to a predetermined total depth t 1 at every second structure line 14 a , 14 b , 14 c , 14 d , 14 e , 14 f produced, as explained above, by appropriate etching, preferably plasma etching, of the masking layer, preferably a chromium layer, by means of an appropriate, further etching process, preferably a plasma etching process.
In the region of the structure lines 14 a, 14 b, 14 c, 14 d, 14 e, 14 f, the substrate layer, preferably a layer, either has a relatively small total depth t 0 , or a relatively large total depth t 1 .
When such a photomask is positioned above a corresponding wafer and is exposed, it is achieved that respectively adjacent structure lines 14 a , 14 b , 14 c , 14 d , 14 e , 14 f —and thus light waves passing through correspondingly more or less deep positions of the substrate layer, preferably a quartz layer, are phase-distorted against each other by 180°, whereby—due to interference effects between the light waves—correspondingly more sharply limited intensity maxima of the light waves can be produced on the wafer than with the use of conventional photomasks.
Apart from the above-described types of masks, any further types of photomasks may also be used as photomask 11 , e.g. a tritone mask composed of three different layers (e.g. a chromium, a quartz and a phase-shifting layer), etc.
Alternatively, instead of a photomask, also an appropriate non-optical mask may be used, preferably a NGL (Next Generation Lithography) mask, e.g. an ultraviolet mask, in particular an EUV (Extended Ultraviolet) mask, or an IPL (Ion Projection Lithography) mask, etc.
The photomask 11 illustrated in FIG. 2 is—as will be explained in more detail in the following—used for the exposure of partial regions (here in particular e.g. for the exposure of the cell regions) of a particular level or layer of the wafer (or for the exposure of particular partial regions (here in particular e.g. for the exposure of the cell regions) of a particular level or layer of the semiconductor devices or chips to be produced on the wafer)—although the above-mentioned layout structure 18 also extends over non-cell regions (and beyond them).
For the exposure of the remaining partial regions of the corresponding level or layer of the semiconductor devices or chips to be produced on the wafer, a further photomask corresponding, for instance, to the photomask 21 illustrated in FIG. 3 , is used, as will also be explained in more detail further below.
The photomask 11 illustrated in FIG. 2 may—in addition to the exposure of partial regions of the above-mentioned (first) level or layer—also be used for the exposure of partial regions (in particular e.g. for the exposure of the cell regions) of one or a plurality of further levels or layers differing from the above-mentioned level or layer of the wafer (e.g. positioned above and/or below) (e.g. for the exposure of partial regions (in particular e.g. for the exposure of the cell regions) of one or a plurality of further levels or layers of the semiconductor devices or chips to be produced on the wafer)—e.g. for one or a plurality of further levels with correspondingly identical cell (line) structure as the above-mentioned level, or e.g. a cell (line) structure distorted by 90° (cf. explanations below).
For the exposure of the remaining partial regions of the corresponding further level(s) or layer(s) of the semiconductor devices or chips to be produced on the wafer, the above-mentioned photomask corresponding to the photomask 21 illustrated in FIG. 3 is used, or a (third) photomask (not illustrated here) having correspondingly different structures as the photomask 21 .
As is illustrated in FIG. 3 , the further photomask 21 adapted to be used—together with the photomask 11 illustrated in FIG. 2 —for the exposure of an individual level or layer of a wafer (or of an individual level or layer of the semiconductor devices or chips to be produced thereon, respectively) comprises a substrate layer, e.g. a quartz layer (or e.g. a crown glass layer, a borosilicate glass layer, etc.)—positioned at the bottom in the drawing of FIG. 3 —and a masking layer, e.g. a chromium layer (or e.g. an iron oxide layer, etc.) positioned above the substrate or quartz layer.
During the production of the photomask 21 , the (top) masking layer, preferably a chromium layer, is provided with specific layout structures that will still be explained in more detail in the following, wherein—by means of an etching process, preferably a plasma etching process—the masking layer, preferably a chromium layer, is completely removed at the corresponding positions.
As is illustrated in FIG. 3 , the photomask 21 is correspondingly similar to the photomask 1 illustrated in FIG. 1 divided into a plurality of substantially identical, rectangular regions 25 a, 25 b, 25 c, 25 d, 25 e, 25 f, 25 g, 25 h that are each provided with the same layout structure and are arranged array-like side by side in rows 22 a, 22 b, 22 c, 22 d, 22 e, 22 f and columns 23 a, 23 b, 23 c, 23 d, 23 e and forming together an “array region” 29 (In FIG. 3 , the photomask regions positioned in rows 22 b, 22 c, 22 d, and 22 e and in the columns 23 a, 23 b, 23 c, 23 d and 23 e corresponding to the photomask regions 25 a, 25 b, 25 c, 25 d, 25 e, 25 f, 25 g, and 25 h are illustrated, remaining photomask regions are partially illustrated by means of appropriate dots).
Each of the above-mentioned photomask regions 25 a , 25 b , 25 c , 25 d , 25 e , 25 f , 25 g , 25 h (or a respective partial region thereof, cf. below) is—as will be explained in more detail in the following—used for the exposure of a partial region (in particular e.g. of the non-cell region) of a particular, individual semiconductor device or chip to be produced on the wafer.
Central regions 26 a , 26 b , 26 c , 26 d , 26 e , 26 f , 26 g , 26 h that are of a substantially rectangular shape and that each have, on particular, individual memory devices to be produced on the wafer, assigned regions on which the—actual—memory device memory cells are produced (“cell regions” 26 a , 26 b , 26 c , 26 d , 26 e , 26 f , 26 g , 26 h ) are each positioned centrally in the corresponding photomask regions 25 a , 25 b , 25 c , 25 d , 25 e , 25 f , 25 g , 25 h , as is illustrated in FIG. 3 . Alternatively, several, e.g. four, nine, or sixteen, etc. corresponding (cell) regions—positioned side by side—may also be arranged in each photomask region 25 a , 25 b , 25 c , 25 d , 25 e , 25 f , 25 g , 25 h instead of one individual central or cell region 26 a , 26 b , 26 c , 26 d , 26 e , 26 f , 26 g , 26 h.
Other than with the photomask 1 illustrated in FIG. 1 , the cell regions 26 a , 26 b , 26 c , 26 d , 26 e , 26 f , 26 g , 26 h with the photomask 21 according to FIG. 3 are not provided with a layout structure (in particular e.g. not with structure lines)—although the corresponding level or layer, respectively, of the memory devices to be produced on the wafer has to be exposed with a structure, preferably a line structure, at the regions corresponding to the cell regions 26 a , 26 b , 26 c , 26 d , 26 e , 26 f , 26 g , 26 h (this happens—as will still be explained in more detail in the following—not by means of the photomask 21 illustrated in FIG. 3 , but by making use of the photomask 11 illustrated in FIG. 2 ).
Instead, the photomask 21 is—as illustrated in FIG. 3 —completely or substantially completely covered with the above-mentioned masking layer, preferably a chromium layer, at the cell regions.
In accordance with FIG. 3 , substantially identical, frame-shaped regions 27 a , 27 b , 27 c , 27 d , 27 e , 27 f , 27 g , 27 h are positioned around the structureless or substantially structureless central regions (“cell regions”) 26 a , 26 b , 26 c , 26 d , 26 e , 26 f , 26 g , 26 h —also in the above-mentioned photomask regions 25 a , 25 b , 25 c , 25 d , 25 e , 25 f , 25 g , 25 h (which are each assigned to particular, individual semiconductor devices).
The regions 27 a , 27 b , 27 c , 27 d , 27 e , 27 f , 27 g , 27 h may be provided with respectively identical or substantially identical layout structures.
These may, for instance, serve for the exposure of regions on the wafer on which the structures surrounding the—actual—memory device memory cells, possibly connected thereto, are produced (e.g. corresponding (connecting or pad) logic devices, (connecting) lines, spines, kerfs, etc. serving, for instance, for connection of the memory cells to the outside) (“non-cell regions” 27 a , 27 b , 27 c , 27 d , 27 e , 27 f , 27 g , 27 h ).
The layout structures provided at the respective regions 27 a , 27 b , 27 c , 27 d , 27 e , 27 f , 27 g , 27 h of the photomask 21 correspond to corresponding layout structures to be produced at the respective regions of the above-mentioned semiconductor device level or layer, respectively.
The layout structures provided at the respective regions 27 a , 27 b , 27 c , 27 d , 27 e , 27 f , 27 g , 27 h of the photomask 21 may, for instance, have (minimal) structure widths and/or (minimal) mutual distances of e.g. approx. 30 nm-600 nm, in particular 50 nm-250 nm (wherein the (minimal) structure widths or mutual distances may—depending on the optical device that is later on connected between a corresponding wafer and the photomask 21 —e.g. correspond (with 1:1 photomasks) to the (minimal) structure widths or distances of layout structures to be produced—later on—on the wafer by means of the photomask 21 , or (with 4:1 photomasks) e.g. to a four-fold thereof, etc., etc.
For the photomask 21 , apart from the type of mask described above, any other type of photomask may also be used, e.g. as described above in the connection with the photomask 11 illustrated in FIG. 2 —an alternating phase mask or e.g. a tritone mask constructed of three different layers (e.g. a chromium, a quartz, and a phase shifting layer), etc.
Alternatively, instead of a photomask, also an appropriate non-optical mask may be used, in particular a NGL (Next Generation Lithography) mask, e.g. an ultraviolet mask, in particular an EUV (Extended Ultraviolet) mask, or an IPL (Ion Projection Lithography) mask, etc.
In accordance with FIG. 3 , the above-mentioned photomask regions 25 a , 25 b , 25 c , 25 d , 25 e , 25 f , 25 g , 25 h —used for the exposure of particular, individual semiconductor devices—are arranged in each row 22 a , 22 b , 22 c , 22 d , 22 e , 22 f and column 23 a , 23 b , 23 c , 23 d , 23 e in vertical and horizontal direction each with certain—equidistant—distances from one another. The regions of the photomask 21 positioned (directly) between the regions 25 a , 25 b , 25 c , 25 d , 25 e , 25 f , 25 g , 25 h (and resulting from the distances of the regions 25 a , 25 b , 25 c , 25 d , 25 e , 25 f , 25 g , 25 h from one another) are not used for the exposure of layout structures of the semiconductor devices to be produced on the wafer (but are each assigned to regions on the wafer positioned between the semiconductor devices to be produced and are therefore completely or substantially completely covered with the above-mentioned masking layer, preferably a chromium layer).
With alternative embodiments, the photomask regions 25 a , 25 b , 25 c , 25 d , 25 e , 25 f , 25 g , 25 h may also be positioned directly adjacent to one another—without a distance therebetween.
The photomask 21 illustrated in FIG. 3 is—as has already been explained—only used for the exposure of partial regions—in particular e.g. of the non-cell regions (i.e. the structures directly surrounding the—actual—memory device memory cells, possibly connected thereto)—of a particular level or layer of the corresponding semiconductor devices or chips to be produced on the wafer.
To this end, the photomask 21 is positioned between a light source and the corresponding wafer (wherein appropriate optical devices—in particular those comprising an appropriate lens system—may be provided between the light source and the photomask 21 and/or between the photomask 21 and the wafer).
For the—preceding or subsequent—exposure of further partial regions of the same level or layer of the semiconductor devices or chips to be produced on the wafer (in particular for the exposure of the cell regions (i.e. of those regions on which the—actual—memory device memory cells are produced)) there serves—as has already been explained above—the photomask 11 illustrated in FIG. 2 .
Since this photomask 11 is—as explained above—completely or over the entire product field or array region 19 provided with the above-mentioned layout structure 18 , particular (partial) regions not to be exposed with the photomask 11 (in particular the non-cell regions (and the regions of the array region 19 positioned between different non-cell regions) are faded out during the exposure of the corresponding wafer with the photomask 11 .
To this end, for instance, an aperture means corresponding to the aperture means 31 illustrated in FIG. 4 (viewed from the top there) may be used.
The aperture means 31 is—during the exposure of the wafer with the photomask 11 —positioned, for instance, between the wafer and the photomask 11 (e.g. directly above the wafer, or below an optical device positioned between the wafer and the photomask—preferably an optical device comprising an appropriate lens system—, or e.g. directly below the photomask, or above the optical device positioned between the wafer and the photomask, etc.), or, for instance, between the photomask 11 and an appropriate light source (e.g. directly above the wafer, or below an optical device positioned between the light source and the photomask—preferably an optical device comprising an appropriate lens system—e.g. below an appropriate stepper or scanner device).
Alternatively, the aperture device 31 may, for instance, also be part of the optical device positioned above the photomask (in particular an optical device comprising an appropriate lens system), in particular part of the above-mentioned stepper or scanner device (so that an appropriate stepper or scanner aperture is then formed by the aperture device 31 ).
As is illustrated in FIG. 4 , and as will be explained in more detail in the following, the aperture device 31 is designed to be transparent in certain regions 36 a , 36 b , 36 c , 36 d , 36 e , 36 f , 36 g , 36 h , and otherwise non-transparent (or partially transparent) (non-transparent or partially transparent region 38 ).
For providing the above-mentioned (transparent or non-transparent (or partially transparent)) regions 36 a , 36 b , 36 c , 36 d , 36 e , 36 f , 36 g , 36 h , or 38 , respectively, the aperture device 31 may, for instance, comprise a transparent layer, e.g. a quartz layer—positioned at the bottom in the drawing of FIG. 4 —over the entire face of which (or at least over a region corresponding to the above-mentioned array region 19 ) a non-transparent layer, e.g. a chromium layer, is positioned, said layer being provided with appropriate recesses at the above-mentioned transparent regions 36 a , 36 b , 36 c , 36 d , 36 e , 36 f , 36 g , 36 h.
The above-mentioned transparent regions 36 a, 36 b, 36 c, 36 d, 36 e, 36 f, 36 g, 36 h are substantially identical and, for instance, of rectangular design and are over the entire region corresponding to the above-mentioned array region 19 arranged array-like side by side in rows 32 a, 32 b, 32 c, 32 d, 32 e, 32 f and columns 33 a, 33 b, 33 c, 33 d, 33 e (In FIG. 4 , the regions positioned in rows 32 b, 32 c, 32 d, and 32 e and in columns 33 a, 33 b, 33 c, 33 d and 33 e corresponding to the regions 36 a, 36 b, 36 c, 36 d, 36 e, 36 f, 36 g, and 36 h are illustrated, remaining photomask regions are partially illustrated by means of appropriate dots).
The transparent regions 36 a , 36 b , 36 c , 36 d , 36 e , 36 f , 36 g , 36 h correspond in their relative position and their proportions (possibly after appropriate imaging on the wafer by the above-mentioned optical device) to the above-mentioned wafer cell regions on which the—actual—memory device memory cells are to be produced.
The above-mentioned non-transparent region 38 of the aperture device 31 serves—during the exposure of the wafer by means of the photomask 11 —for fading out of those regions (here: in particular the non-cell regions and the regions between the non-cell regions) of the wafer that are not to be exposed during the use of the photomask 11 .
In other words, the aperture device 31 —in particular its non-transparent region 38 —prevents rays transmitted by the above-mentioned light source from hitting the above-mentioned non-cell regions.
Contrary to this—due to the transparency of the above-mentioned regions 36 a , 36 b , 36 c , 36 d , 36 e , 36 f , 36 g , 36 h of the aperture device 31 —the remaining partial regions of the wafer (in particular the above-mentioned cell regions) are exposed with the above-mentioned structure 18 provided on the photomask 11 .
The fading out of the above-mentioned partial regions, in particular the non-cell regions (and the wafer regions positioned therebetween), and the sole exposure of the remaining partial regions, in particular the cell regions, can, with the use of a mask corresponding to the photomask 11 illustrated in FIG. 2 , also be achieved in any other way than with the above-mentioned aperture device 31 .
An appropriately designed lithography scanner providing a region-fade-out-function may, for instance, be used for exposure of the wafer.
The use of the photomask 11 in forming a feature using a lithographic scanner is next described. A bundle of rays emitted by the appropriate scanner is directed in a substantially vertical direction from the top on the photomask 11 positioned between the wafer and the scanner. The resulting cone of light is rastered over the face of the photomask 11 along particular scanning directions that are substantially parallel to one another e.g. the scanning directions A, B, and C illustrated in FIG. 2 ).
Regions positioned vertically relative to the respective scanning directions A, B, C that do not have to be exposed may, for instance, be faded out by corresponding shutters provided at the scanner and extending in horizontal (or e.g. vertical) direction to the scanning direction, and regions positioned horizontally to the respective scanning directions A, B, C—that possibly do not have to be exposed—may be faded out by the scanning gap at the scanner being covered appropriately (completely or partially).
The above mentioned photomask 11 may—contrary to conventional photomasks—be used for the exposure of different levels or layers—having the same structure at the above-mentioned cell regions—of one and the same wafer.
Furthermore, it is possible to use the above mentioned photomask 11 for the exposure of different wafers having partially different structures (e.g., when particular levels or layers of the wafers have the same structure at the above-mentioned cell regions).
Moreover, the above-mentioned photomask 11 may, for instance, be used for the exposure of levels or layers—having identical structures at the above-mentioned cell regions which are, however, oriented in a way distorted vis-à-vis one another (in particular having identical structures apart from a 90° rotation)—of one and the same wafer, or for the exposure of—different—wafers having partially different structures (namely when particular levels or layers of the wafers have the same structure, apart from a rotation, in particular a 90° rotation, at the above-mentioned cell regions).
During exposure, the photomask 11 may be rotated, for example, by 90 degrees to align with the orientation of the respective target structure (cf. Arrow D, FIG. 2 ).
As results, for instance, from FIGS. 2 and 3 , the photomask 11 has—as compared to conventional photomasks 1 —moreover i.e., the advantage that it is of substantially more homogeneous structure than conventional photomasks.
When the photomask 11 has, at a particular position (which is exposed with respect to the wafer with a standard orientation of the photomask 11 ), the defect may, by appropriate shifting of the photomask 11 in vertical and/or horizontal direction (e.g. along the Arrow E and/or F illustrated in FIG. 2 ), be shifted in a region that is faded out during exposure—e.g. by the above-mentioned aperture device 31 .
Due to this fact, the photomask 11 may—despite the defect—(still) be used for wafer exposure.
|
A mask set for the production of integrated circuit chips, wherein a first mask has first features that form inner cell regions and a second mask has second features that form outer non-cell regions, so that the first and second masks do no expose a same region of a semiconductor wafer. An exposure system includes the mask set with an aperture device to fade out partial regions of the first features during exposure of the wafer by a light source. Furthermore, the mask set is used in a method of exposing a wafer for producing integrated circuit chips.
| 6
|
BACKGROUND OF THE INVENTION
The invention relates to a tensioner for an endless power transmission member such as an endless belt chain or the like, and a power transmission system that includes such a tensioner and power transmission member. More particularly, the invention relates to a spring type tensioner that biases the position of a pivot arm to which a rotatable pulley is mounted. While the tensioner of the invention may be used in various applications for tensioning and endless power transmission member, it is particularly useful in controlling belt tension of a V-ribbed belt as associated with front end accessory drives or a synchronous belt as associated with cam shaft drive systems for automotive applications.
Tensioners of the pivot arm type may use various types of spring bias means such as belville springs, volute springs, compression springs, or torsional coil springs. While the art discloses various types of spring means, the coil torsional spring is in prevalent use today in automotive applications. Examples of such tensioners with torsional springs are disclosed in U.S. Pat. No. 4,473,362 and U.S. Pat. No. 4,696,663. Although such tensioners are in wide spread use in automotive applications for satisfactorily controlling tension in a power transmission belt, the torsional springs used in such tensioners inherently introduce some design application problems which have to be considered for each power transmission system. For example, the torsional spring characteristically is positioned in some fashion about a pivot axis with one end operatively connected to a pivot arm and another end operatively connected to some type of support structure. Such an arrangement inherently introduces a couple about the pivot which must be carried both by the pivot and any pivot bushing that may be used.
Coiled torsional springs inherently introduce a variable force on the pivot arm which force varies in accordance with the spring's rate and consequently, the torque output of the pivot arm varies with the spring rate. Also in such tensioners, a component part of the spring force is typically used to effect variable damping of the pivot arm. In the '362 type of tensioner, a radially inward force results from winding the spring around the pivot and "pinching" an elastomeric bushing to effect a majority of a damping torque reacted at the pivot arm. the '663 tensioner, a radially outward force is generated by one of the spring ends which is used to press against a shoe type member against a cup to effect a damping torque reacted at the pulley. In both types of tensioners, the damping torque that is generated varies as a function of a spring rate and with movement of the pivot arm.
However, a goal in many tensioning applications is to provide a substantially constant force at a pulley so that a constant tension is achieved in the power transmission member such as an endless belt. To do this, torsional spring type tensioners must be mounted with their pivot arms angled in a geometric manner relative to the belt so that a trigonometric shortening and lengthening of the pivot arm compensates for variations introduced by the coiled torsional spring. Since the same spring is used to provide both a biasing force and a damping force in such tensioner designs, often times an iterative process is used to find a spring that will provide the necessary bias force and generate the necessary damping force for a particular geometric positioning of the pivot arm.
This invention is directed to circumvent the inherent drive design problems associated with coil torsional springs by using a compression spring to bias movement of a pivot arm and a second spring means to effect damping of the pivot arm. An example of a tensioner that uses a compression spring to bias movement of a pivot arm and a separate spring for damping appears in U.S. Pat. No. 4,299,584. In the '584 tensioner, the spring is retained in a tubular spring housing that is fixed to a support structure that does not move with movement of the pivot arm. The housing holds the spring in an aligned position relative to the support structure so that the compression spring like the torsional coil spring of the '362 and '663 patents, introduces a variable force on the pivot arm such that the torque output of the pivot arm varies with the spring rate. Also, the geometric arrangement of the '584 tensioner does not compensate for the variable torque output of the pivot arm and consequently, variable tension levels are introduced into the belt may be undesirable. Furthermore, the damping of the pivot arm is substantially constant because the damping means of a leaf spring exerting a constant force on a pad of friction material; this may be an undesirable combination with the variable torque output of the pivot arm for some drive applications.
SUMMARY OF THE INVENTION
In accordance with the invention, a tensioner is provided that is useful in conjunction with a flexible power transmission member in a drive system. The invention is particularly useful in power transmission belt systems such as those used in synchronous belt drive systems or V-ribbed front end accessory belt drive systems, both used in automotive applications.
The belt tensioner of the invention is of the pivot type with an idler pulley rotatably mounted to a pivot arm, a first spring to bias movement of the pivot arm, and a second or damping spring for inhibiting movement of the pivot arm. In accordance with the invention, a compression spring is used and is interpositioned between a support structure and the pivot arm in such a manner that the spring is permitted to move or articulate to change its effective lever arm or moment arm for all operative movements of the pivot arm. The mounting of a compression spring permits designing a tensioner where the torque output need not vary as a function of the spring rate, but rather, the torque may, in some applications, be designed to be substantially constant. When such a tensioner is used in a power transmission system with a flexible power transmission member, a substantially constant tension may be achieved without special geometric orientations of the tensioner. Alternatively, a geometric orientation may be used in combination with a changing of the moment arm of the spring to effect a new option in designing a tensioner for use in a particular power transmission system.
An advantage of the invention is that since there need be no geometric limitations of tensioner orientation to compensate for changes in torque output of the pivot arm, the tensioner may be fit within small space envelopes not achievable by prior art tensioners.
An object of the invention is to provide a tensioner where constant torque output of the pivot arm may be achieved. An advantage of such an object is that constant damping may be used and that the effects of the bias spring and damping spring may be independently varied for ease in adapting a tensioner to a particular power transmission system.
An advantage of the invention is that a change in spring rate of the pivot arm bias spring does not effect a change in the damping forces and conversely a change in the spring rate of a damping spring does not effect a change in the force of the spring of the pivot arm.
Another object of the invention is to use a compression spring where forces on a pivot may be minimized by reducing loads on the pivot whereby an integrally molded pivot may be used in lieu of a traditionally more expensive and stronger bolt or pin.
These and other objects or advantages of the invention will be apparent after reviewing the drawings and description thereof wherein:
FIG. 1 is a partial schematic front view of a drive system that includes a power transmission member such as a belt and a belt tensioner of the invention;
FIG. 2 is an enlarged partially broken away view of the belt tensioner of FIG. 1;
FIG. 3 is a view taken along the line 3--3 of FIG. 2;
FIG. 4 is a view taken along the line 4--4 of FIG. 2;
FIG. 5 is a view taken along the line 5--5 of FIG. 2;
FIG. 6 is a partial and partly broken view of FIG. 2 in the vicinity of line 3--3 showing alternate means for mounting a spring; and
FIG. 5 is a schematic view showing an exaggerated force diagram for a compression spring of the tensioner of FIG. 2.
DESCRIPTION OF PREFERRED EMBODIMENTS
While various features of the tensioner may be used in several power transmission systems that use a flexible power transmission member, the features are perhaps best described in conjunction with an automotive belt drive. Referring to FIG. 1, a belt drive system 10 is shown with a belt 12 entrained and tensioned around pulleys 14, 16. A tensioner 18 of the invention is interpositioned between belt spans 20, 22 where a pulley 24 engages the belt.
Referring to FIG. 2-5, the belt tensioner 18 is of the spring biased type and includes a support structure 26, a pivot arm 28, and a spring 30 biased between the support structure and pivot arm. The pivot arm 28 is pivotably mounted to the support structure by means of a pivot 32 and an optional, self lubricating polymeric sleeve-type bearing or bushing 34 that includes a thrust flange 36.
The pulley 24 is rotatably mounted to the pivot arm such as by means of a roller ball bearing 38 and is operative at a moment arm or lever arm LP from the pivot 32 as the pulley moves with the arm structure in pressing engagement against the belt.
The spring is a compression spring and is interpositioned between a post 38 of the support structure and is operative at a variable moment or lever arm LA, LB which is hereinafter further explained. The spring is mounted to the support structure and pivot arm so that the spring articulates with movements of the pivot arm and operates at a moment arm LA, LB that varies in length with articulated movements of the spring. The moment arm shortens with a shortening of length of the compression spring and lengthens with a lengthening of the compression spring as the pivot arm is pivoted. This is diagrammatically shown in FIG. 7 where the spring and its moment arm in one position is shown in solid form and, when pivoted, is shown in dotted form. Satisfactory combinations can be obtained where the length of the moment arm relative to the compressed length of the spring are from about 80 to 100 percent of each other.
Various means may be used for articulately mounting the spring to the support structure and pivot arm. A preferred means is illustrated in FIGS. 2 and 3. The post 38 of the support structure has a projection that includes a slot 40 that is substantially parallel to the pivot. Similarly, a projection on the pivot arm has a slot 42 which is also substantially parallel to the pivot. As best shown in FIG. 3, each end of the spring has an extension 44, 46, that fits in one of such slots. The slots, being substantially parallel with the pivot, allows the extended portions of the spring at each end to slightly rotate in each slot as the spring articulates to a new position as shown in dotted form in FIGS. 2 and 7.
Additional examples of means for articulately mounting the spring are illustrated in FIG. 6. One such means is in the form of a cup 48 having an inside diameter that is larger than the spring diameter so that the end portion of the spring may be inserted in the cup for retention. Another means for articulately mounting the spring is a boss 50 having an outside diameter less than the inside diameter of the spring so that the post may be inserted into one end portion of the spring. In such articulate mountings, the spring may slightly bow as illustrated by the dotted line as the pivot arm reciprocally moves between its operative positions.
A damping means 54 is included for inhibiting movement of the pivot arm and hence, the pulley against the belt when in use. The damping means includes a leg or lever extension 56 of the pivot arm, a damping spring 58 attached 60 to the support structure, a surface 62 of the support structure and a pad 64 of friction material. The leg 56 as an extension of the pivot arm structure, pivotably moves therewith in an arcuate damping zones as shown between the two positions in FIG. 1 and bounded by dotted lines 66. The damping spring may be a compression spring or is preferably in the form of a U-shaped leaf spring with a leg portion 68 juxtaposed the damping zone.
While the pad of friction material may be attached to the surface 62 of the support structure or the leg 68 of the spring 58, it is preferably carried by the leg 56. It is preferred that the leg have an aperture through which the pad of friction material is disposed and protrude at its opposite ends from oppositely facing sides of the leg portion as is shown in FIG. 4. In such an arrangement, the opposite ends of the pad are in friction surface sliding contact with the face 62 of the support structure and leg 68 of the spring. An advantage of positioning the friction material in the aperture of the leg is that it defines a means to adjust to a zero clearance between the arcuate movement of the leg portion and the surface of the support structure.
The pad of friction material may be of any chosen type but it optionally may be in the form of a polymeric material such as that sold under the trademark Delrin which exhibits a starting (static) friction that is less than its sliding (dynamic) friction.
The leaf spring 58 in contact with the polymeric pad and surface, provides substantially a constant damping force at a moment arm or lever LD in relation to the pivot 32. Preferably, the moment or lever arm LD for the damping means is greater than the operative moment arm between LA, LB for the spring to minimize the damping spring force while simultaneously precisely controlling the damping torque of the tensioner.
As illustrated by the vertical alignment of the support structure of FIGS. 3, FIG. 4, and FIG. 5, the spring 30, the damping means with leg 56, friction pad 64, and spring 58, are in substantially planer alignment for the advantage of minimizing or eliminating offset moments that could occur if such elements were not in alignment. Such an arrangement has the advantage of minimizing bearing sizes, pivot sizes, spring sizes and the like.
Use
In use, the tensioner 18 of the invention is positioned so that the pulley 24 is pressed against the belt forming spans 20, 22 that have an included angle A and define a line 70 that bisects such angle. The tensioner 18 may be held in its drive position such as by means of fasteners such as bolts 72, 74. The belt 22 imparts a force F that is substantially along the line 70 which bisects the angle A. Preferably, but optionally, the pivot arm is aligned at an angle B but is from about 80 to about 100 degrees relative to the force F on the pulley.
As best illustrated with reference to the force diagram of FIG. 7 and in conjunction with the motion illustrated by dotted lines in FIG. 2, the spring 30 exerts a force FA on the pivot arm at an operative moment or lever arm LA. As the pivot arm is moved to a second position, the spring shortens as illustrated by the dotted form in FIG. 7 and exerts a force FB at a shorter moment or lever arm LB. The moment arm varies in length with articulated movements of the spring where the moment arm shortens with a shortening of length of the compression spring, and lengthens with a lengthening of the compression spring as the pivot arm is pivoted. As a compression spring, the spring exerts a force FA, FB on the pivot arm that substantially lineally varies with the compressed length of the spring. More preferably, the mean product of the spring force and moment arm throughout the travel of the pivot arm is substantially constant. By making the means product of the spring force and moment arm substantially constant, the tensioner arm of the invention receives a substantially constant torque that is reacted at the pulley by an equal and opposite constant belt tension. The leaf spring operating on the friction pad provides a damping force at the pulley which is also substantially constant.
As shown in FIG. 2, the spring exerts a force on the pivot arm that is in a general direction of the pulley. The spring does not introduce a couple into the pivot or the pivot bushing and consequently, the pivot may be made without the need of a high strength or hardened part. As shown in FIG. 4, the pivot is an integrally molded part of the support structure and may be made of a lower strength material than steel such as aluminum or alloys thereof.
The foregoing example of use is illustrative of a geometric alignment where the pivot arm need not be angularly disposed so that a trigonometric foreshortening of the pivot arm is required to compensate for nonlinear torque outputs of the pivot arm. However, the principles of the invention may be used so that the geometry of the pivot arm as well as the articulated spring of the invention may be used in conjunction with each other to effect another solution to tensioner application problems.
The foregoing detailed description is made for the purpose of illustration only and is not intended to limit the scope of the appended claims.
|
A tensioner with a pulley rotatably mounted onto a pivot arm where movement of the pivot arm is biased with a compression spring and movement is inhibited with a damping device. The compression spring is articulately mounted in such a manner that the torque output measured at the pivot arm may be substantially constant if so desired.
| 5
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is the first application filed for the present invention.
TECHNICAL FIELD
[0002] The present invention relates to common house lamps, and more specifically, to electric lamps which are usable in certain religious observances such as those used by observant Jews during Sabbath.
BACKGROUND OF THE INVENTION
[0003] According to Halachah (traditional Jewish law), manipulating electricity during Sabbath is prohibited. Therefore, such activities as turning on or off a light switch is an infringement of Jewish law. In order to avoid these activities, it is common practice to either leave the lights on permanently during the periods of religious observance, or simply program timers that will automatically shut off the light at a predetermined time.
[0004] Several inconveniences can occur as a result of these limitations. For instance, if timers are set, it must be determined in advance what time the lights should be shut off at. Should there be a change of plan during the evening, it is not possible to reset the timers once Sabbath has started. As for leaving the light on all night, this is not a valid option in the bedroom, where darkness is eventually desired in order to sleep. In addition, intentionally touching a lamp during the Sabbath can constitute an infringement of the rules when they are followed in their strictest sense. In this case, one cannot pick up a lamp and move it into another room when the time comes to remove the light.
[0005] Some have attempted to cover lamps with dark clothing or opaque objects to prevent light from coming through without physically turning off the light. In addition to being a dangerous fire hazard, this practice is not an aesthetic one and may not completely block all light from being emitted from the lamp.
[0006] The prior art suggests various contraptions used to block light. For example, U.S. Pat. No. 4,809,145 to Bennett describes a free-standing and self-supporting lamp shade that could be placed over a lamp to block out the light, while leaving holes for the escape of heat. A shade base is provided to receive the shade. Using this device, light is not completely blocked, as can be seen in the figures. U.S. patent application 2003/0026099 to Dutka et al. describes an illumination device used to block out light for religious observance. While light is completely blocked using this device, the apparatus is complicated to make and is not compatible with standard lamps that may already be present in the home, nor can it be used as an ordinary house lamp.
[0007] Therefore, there is a need to provide an apparatus which will be aesthetically appealing and will allow one to selectively block out all light emitted from a lamp without requiring the kindling or extinguishing of electricity.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to overcome the drawbacks of the prior art by providing a simple design for a lamp that will allow a religious person to observe Jewish law during Shabbat.
[0009] It is also an object of the present invention to provide a device compatible with a standard lamp, that uses standard hardware, and can be adapted to a variety of existing lamp models already out on the market.
[0010] It is yet another object of the present invention to provide a device that can substitute a standard lamp.
[0011] In accordance with a first aspect of the present invention, there is provided a lamp for selectively blocking out light, the lamp comprising: a lamp body having a socket at one end for receiving a light bulb and electrically powering the light bulb; a removable opaque covering dome to be placed on top of the light bulb for substantially blocking all light being generated by the light bulb; a lamp shade having mounting means for mounting the lamp shade to the socket, and an upper aperture allowing vertical access to the light bulb for placing the dome over the light bulb within the lamp shade; and a support platter positioned substantially around the socket for supporting the covering dome such that the covering dome is independent of the lamp and does not come into contact with the lamp body and the light bulb.
[0012] In accordance with a second broad aspect of the present invention, there is provided a kit for use in combination with a lamp used to selectively block out light, the lamp having a lamp body with a socket at one end for receiving a light bulb and electrically powering the light bulb, the kit comprising: a lamp shade having mounting means for mounting the lamp shade to the socket, and an upper aperture allowing vertical access to the light bulb for placing a dome over the light bulb within the lamp shade; and a support platter positioned substantially around the socket for supporting the covering dome such that the covering dome is independent of the lamp and does not come into contact with the lamp body and the light bulb.
[0013] In accordance with a third broad aspect of the present invention, there is provided a kit for use in combination with a lamp used to selectively block out light, the lamp having a lamp body with a socket at one end for receiving a light bulb and electrically powering the light bulb, the kit comprising: a removable opaque covering dome to be placed on top of the light bulb for substantially blocking all light being generated by the light bulb; and a support platter positioned substantially around the socket for supporting the covering dome such that the covering dome is independent of the lamp and does not come into contact with the lamp body and the light bulb.
[0014] In accordance with a fourth broad aspect of the present invention, there is provided a lamp for selectively blocking out light, the lamp comprising: a lamp body having a lower base at a first end and a socket at a second end for receiving a light bulb and electrically powering the light bulb; a support platter directly connected to the socket, the support platter having a substantially centrally positioned aperture to mate with the socket; and a removable opaque covering dome to be placed over the light bulb and onto the support platter for substantially blocking light being generated by the light bulb.
[0015] Preferably, the lamp has a socket of the type which has a threaded ring used to secure a lamp shade with its own annular ring that is fitted around the socket. In this case, the support platter is placed between the ring of the lamp shade (its mounting means) and the threaded ring and no changes need to be made to the standard lamp. Alternatively, the socket may be of the type used with a harp or another clip adapter to connect lampshades of different styles to the socket. In this case, the harp or adaptor, which is usually attached to a lower part of the socket, can be cut and the platter can be secured (such as by welding) to the harp or adaptor. A lamp shade allowing the vertical access for the dome is can then be used with the lamp.
[0016] The lamp provided in accordance with the present invention has many advantages over the prior art. For example, a bulb that emits the equivalent of 100 Watts can be used because the heat dissipation within the dome is not a factor. The lamp can also provide 360° of light when the dome is not covering the light bulb. In addition, the lamp of the present invention has a cover that does not constitute an integral part of the lamp itself. It is considered a separate element to the lamp and therefore there is no need to come into contact with the lamp when using the present invention. The proposed lamp is simple and easy to use, while respecting all of the rules of the Jewish religion.
[0017] It should be understood that the various embodiments of the present invention can be used with standard lamp hardware and adapted to a variety of models. For example, all lamps with threaded ring and ring holder can be adapted to be used with the apparatus as described herein. As for the lamp shades, various adaptors allow lamps to accept shades of different styles. An adaptor that provides the upper aperture for allowing vertical access to the light bulb is compatible with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
[0019] FIGS. 1 a - 1 f are front elevation views of the lamp components in accordance with a preferred embodiment of the present invention;
[0020] FIG. 2 is an exploded view of the lamp as assembled, in accordance with a preferred embodiment of the present invention;
[0021] FIG. 3 is a front elevation view of the assembled lamp with the components under the lamp shade shown in dotted lines, in accordance with a preferred embodiment of the present invention;
[0022] FIG. 4 is a front elevation view of the assembled lamp without the lamp shade and with the covering dome, in accordance with a preferred embodiment of the present invention;
[0023] FIG. 5 is a front elevation view of the assembled lamp without the covering dome and exposing the light bulb, in accordance with a preferred embodiment of the present invention;
[0024] FIG. 6 is a perspective view of the covering dome, in accordance with a preferred embodiment of the present invention;
[0025] FIG. 7 is a front elevation view of a covering dome with a door to selectively let the light through;
[0026] FIG. 8 is a front elevation view of a covering dome with an aperture to let light through;
[0027] FIG. 9 is a front elevation view of a pair of concentric rotatable covering domes to selectively let light through;
[0028] FIG. 10 is a front elevation view showing the lamp shade with the branches and mounting means attached to the top of the shade, in accordance with another embodiment of the present invention.
[0029] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] FIGS. 1 a - 1 f show the lamp of the preferred embodiment in a disassembled state. FIG. 1 a shows a lamp structure 20 that has a base 22 , an elongated body 24 , and a socket 26 at an upper end. An electrical cord 28 extends from the base 22 . The electrical cord 28 is to be connected to a standard wall outlet to provide electricity to the lamp. Alternatively, the lamp may be battery operated and therefore be cordless. Electrically powering the light bulb should be understood as meaning through a wall outlet or a battery. A switch 30 to turn on the lamp can be present on the electrical cord 28 itself, as shown in the figure, or anywhere on the structure of the lamp (not shown). FIG. 1 b is a light bulb 32 , which is to be screwed into the socket 26 of the lamp structure 20 . FIG. 1 c shows a support platter 34 with a flange 36 around an outer perimeter and a circular aperture 38 positioned centrally. The circular aperture 38 is to be received by the socket 26 of the lamp structure 20 . An annular securing ring 33 having an aperture 35 and threading 37 on its inner surface, as seen in FIG. 1 d , is used to secure the support platter 34 to the socket 26 of the lamp structure 20 . This hardware can be a standard threaded ring as found in common lamps, or a new piece of hardware provided especially for the present invention. FIG. 1 e shows a covering dome 40 . The dome 40 has a hollow interior and a circular base. A handle 41 is used to manipulate the dome 40 . A lamp shade 42 is shown in FIG. 1 f . The lamp shade 42 has an aperture 44 at an upper end thereof for allowing vertical access from the top. Mounting means, such as the attachment ring 46 and the three branches that connect the ring 46 to the base of the shade 42 are used to mount the lamp shade 42 to the lamp structure 20 . The ring 46 is to be received by the socket 26 of the lamp structure 20 . The lamp shade may be removably mounted to the lamp structure, or permanently mounted, such as by welding.
[0031] As per FIG. 2 , the various components of the lamp seen in FIG. 1 are assembled together to form the lamp. The lamp shade 42 is first placed on the socket 26 . The socket has a narrow upper portion with a smaller diameter than the attachment ring 46 , and a wider lower portion on which the attachment ring 46 rests. From the top opening 44 of the lamp shade 42 , the support platter 34 is placed onto the socket 26 . The securing ring 33 is then placed on top of the support platter 34 and threadingly engages with the socket 26 via its inner threading 37 . The securing ring 33 stabilizes the support platter 34 such that it can support the covering dome 40 . The light bulb 32 is then screwed into the socket 26 of the lamp structure 20 . At this point, the lamp is capable of emitting light when turned on. To block the light while the electricity still powers the light bulb 32 , the covering dome 40 is inserted by the opening 44 of the lamp shade 42 and placed over the light bulb 32 onto the support platter 34 . (or any other assembly order).
[0032] FIG. 3 shows the lamp in a fully assembled state, with the components under the lamp shade 42 shown in dotted lines. The dome 40 sits on the platter 34 and covers the bulb 32 .
[0033] FIG. 4 is a view of the preferred embodiment of the lamp without the lamp shade 42 . A support platter 34 is positioned at socket level of the lamp body 24 . The support platter 34 is a flat surface that receives and supports the covering dome 40 . The flange 36 is used to secure the dome 40 on the support platter 34 and prevent it from falling off. Additionally, it helps to direct the user as the dome 40 is deposited onto the platter 34 .
[0034] FIG. 5 is an enlarged view of the support platter 34 and light bulb 32 assembled to the socket 26 of the lamp. In a preferred embodiment, the light bulb 32 is an energy saving compact fluorescent light bulb for longer life and energy savings. It can be appreciated that any type of light bulb having a base that can mate with the socket of the lamp can be used and that has a similar form factor. The bulbs used can be incandescent, fluorescent, halogen, etc. They can be of the type with the ballast built into the base, or the two-piece type in which the ballast is connected to an adaptor, the adaptor connecting into the light socket. In addition, a light bulb and platter can be integrated into one piece of hardware by having a bulb with an outwardly extending base that is capable of receiving the dome without requiring an additional platter.
[0035] FIG. 6 is a perspective view of the covering dome 40 in accordance with a preferred embodiment of the present invention. The dome 40 is preferably made of ceramic, but can be made of any type of non-melting material, such as metal, plastic, Teflon, etc. The dome 40 defines a hollow interior which completely covers the light bulb 32 and the base seals against the support platter 34 to prevent light from escaping. A handle 41 is used to manipulate the dome 40 . Other embodiments for the handle, such as a hoop or a projecting member, are also possible. It should be noted that the handle is insulated from the rest of the dome and therefore, remains cooler. The handle allows the user to manipulate the dome without getting burned.
[0036] Various embodiments are possible for the dome 40 . The covering dome 40 can be designed with an aperture on a vertical surface thereof and means for closing the aperture for selectively allowing light through the opening. In FIG. 7 , the means for closing the aperture is a door 43 . This door can be sliding or hinged and operable using a small handle. In FIG. 8 , no door is provided directly on the dome 40 . The aperture 45 is on a side of the dome 40 and can be covered using a second dome of larger diameter than the first dome. For example, the dome of FIG. 6 with no aperture, can be placed on top of the dome of FIG. 8 , provided the dome of FIG. 6 is of a larger diameter than that of FIG. 8 . Alternatively, the second dome may also have an aperture on a surface thereof. FIG. 9 displays two such domes ( 40 and 40 ′) one on top of the other. When the two domes ( 40 and 40 ′) are positioned such that the two apertures ( 45 and 45 ′) are aligned, light is projected therethrough. When the two domes ( 40 and 40 ′) are positioned such that the two apertures ( 45 and 45 ′) are not aligned, light is sealed within the covering structure. The dome can be of any shape that can properly cover the light bulb 32 .
[0037] Various embodiments are also possible for the support platter 34 . While the support platter 34 is circular in the preferred embodiment, different shapes are possible as long as the covering dome 40 is properly supported. For example, a square or hexagonal plate would also serve the function, which is to support the covering dome. The support platter 34 may be formed with a threading around an inner surface of the aperture 38 such that it can be threaded onto the socket. In this case, the securing ring 33 is no longer necessary to stabilize the platter 34 . The support platter 34 may have a recess along its surface such that the base of the covering dome fits into the recess and is thereby secured in place (not shown).
[0038] While the lamp shade 42 has been illustrated as an upside-down cone throughout the figures, it should be understood that various shapes are possible. For example, a right-side-up cone or cylindrical shaped lamp shade allowing vertical access to the bulb through the top is also consistent with the present invention. The branches 48 , of which there can be any number greater than two, can be attached to the top of the lamp shade, provided that they afford sufficient room to insert the covering dome via the top of the lamp shade, as shown in FIG. 10 .
[0039] As stated above, the present invention may be adapted to standard lamps. One embodiment of the present invention consists in a kit comprising a lamp shade and a support platter. The kit could additionally have a light bulb included, the light bulb being a special fluorescent light bulb that emits less heat than a standard incandescent light bulb, but still fits within the socket of a standard lamp. Therefore, a lamp having a different type of shade can be adapted by simply replacing the shade such that it allows the vertical dome to be inserted from the top, and the platter is inserted to receive the dome. The dome may be separate from the kit, or included in it.
[0040] In accordance with another embodiment of the present invention, a kit may consist of the dome and the platter. Since some lamps are already equipped with the lamp shades having the vertical access from the top, all that would be needed to adapt a standard lamp to the present invention is the dome and the platter to support the dome. Additionally, a light bulb may also be included in this kit. lamp shade that is completely opaque, sealed on the top and bottom, with a door on it.
[0041] It should be understood that the present invention may be applicable to table lamps, floor lamps, wall lamps (such as swing-arms), etc. The embodiments of the invention described above are intended to be exemplary only. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims.
|
There is described a lamp for selectively blocking out light, the lamp comprising: a lamp body having a socket at one end for receiving a light bulb and electrically powering the light bulb; a removable opaque covering dome to be placed on top of the light bulb for substantially blocking all light being generated by the light bulb; a lamp shade having mounting means for mounting the lamp shade to the socket, and an upper aperture allowing vertical access to the light bulb for placing the dome over the light bulb within the lamp shade; and a support platter positioned substantially around the socket for supporting the covering dome such that the covering dome is independent of the lamp and does not come into contact with the lamp body and the light bulb.
| 5
|
BACKGROUND OF THE INVENTION
(i) Field of the Invention
The present invention relates to novel diaminoindane derivatives and a process for the preparation thereof. The diaminoindane derivatives of the invention are useful as raw materials for isocyanates, epoxy resins, bismaleimides and the like and also as curing agents for isocyanates, for example, RIM urethanes. The diaminoindane derivatives can also be used as curing agents for epoxy resins and bismaleimides and can be added as modifiers to various resins, rubbers and the like.
(ii) Description of the Related Art
Diamine compounds which have been used for the above-described applications prior to the present invention include bis(4-aminophenyl)methane; 2,4-diamino-3,5-diethyltoluene and 2,6-diamino-3,5-diethyltoluene (hereinafter "DETDA" collectively); 2,4-diamino-5-tert-butyltoluene and 2,6-diamino-3-tert-butyltoluene (hereinafter "t-BTDA" collectively).
Bis(4-aminophenyl)methane (hereinafter "MDA") has been prepared by the condensation of aniline with formaldehyde.
As disclosed in U.S. Pat. No. 4,219,502 and European Patent No. 177,916 DETDA and t-BTDA have been prepared by ethylating or tert-butylating 2,4-diamino-toulene or 2,6-diaminotoluene.
The above diamines have both benefits and disadvantages in handling, properties and preparation. For example, bis(4-aminophenyl)methane is economical but has disadvantages such as a high melting point and does not form a homogeneous mixture. It is accompanied by a further drawback that it is unstable to heat, light and oxygen in air, and when employed as a curing agent, the curing reaction proceeds too quickly.
On the other hand, DETDA and t-BTDA which have been prepared by alkylation of diaminotoluenes are generally in a liquid form and enjoy easy handling. Their use as curing agents for RIM urethanes is however accompanied by the drawback that curing proceeds too quickly with DETDA and too slowly with t-BTDA.
SUMMARY OF THE INVENTION
The present invention overcomes the problems and disadvantages of the prior art by providing diaminoindane derivatives useful as raw materials for isocyanates, epoxy resins, bismaleimides and the like and as curing agents for urethanes.
It is an object of this invention to provide novel diaminoindane derivatives having a suitable degree of reactivity and are useful as curing agents for RIM urethanes.
It is a further object of this invention to provide a process for preparing these novel compounds.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the instrumentalities and combinations, particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention comprises diaminoindane derivatives represented by the following formula (I): ##STR2## wherein R 1 and R 2 each represent a hydrogen atom or a lower alkyl group having from 1 to 4 carbon atoms.
The present invention also provides a process for the preparing of the diaminoindane derivatives of the formula (I), comprising dinitrating an indane derivative represented by the following formula (II): ##STR3## wherein R 1 and R 2 have the same meanings as defined above with respect to the formula (I), and then reducting the dinitrated indane derivative.
The diaminoindane derivatives of the invention exhibit a more suitable curing velocity than conventional diamines, particularly when employed as curing agents for RIM urethanes. The diaminoindane derivatives exhibit a degree of reactivity which falls between the reactivities of DETDA and t-BTDA. The diaminoindane derivatives exhibit improved workability and cured articles prepared therefrom have significantly improved properties.
The diaminoindane derivatives of this invention are useful in numerous applications in addition to being useful as curing agents. Furthermore, these compounds may be prepared economically by the process of the invention.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows viscosity increase curves of urethanes in which various diamines were employed as curing agents. Letters A and B represent a diaminoindane derivative obtained in Example 1, and a diaminoindane derivative obtained in Example 3, respectively.
FIG. 2 is an IR spectrum (KBr) diagram of the diaminoindane derivative obtained in Example 1.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiments of applicants' invention.
The diaminoindane derivatives of this invention are represented the formula (I) and include the following exemplary compounds:
5,7-Diamino-1,1-dimethylindane;
4,6-Diamino-1,1-dimethylindane;
4,7-Diamino-1,1-dimethylindane;
5,7-Diamino-1,1,4-trimethylindane;
5,7-Diamino-1,1,6-trimethylindane;
5,7-Diamino-1,1-dimethyl-4-ethylindane;
5,7-Diamino-1,1-dimethyl-6-ethylindane;
5,7-Diamino-1,1-dimethyl-4-isopropylindane;
5,7-Diamino-1,1-dimethyl-6-isopropylindane;
5,7-Diamino-1,1-dimethyl-4-n-propylindane;
5,7-Diamino-1,1-dimethyl-6-n-propylindane;
5,7-Diamino-1,1-dimethyl-4-sec-butylindane;
5,7-Diamino-1,1-dimethyl-6-sec-butylindane;
5,7-Diamino-1,1-dimethyl-4-n-butylindane;
5,7-Diamino-1,1-dimethyl-6-n-butylindane;
5,7-Diamino-1,1-dimethyl-4-tert-butylindane;
5,7-Diamino-1,1-dimethyl-6-tert-butylindane;
5,7-Diamino-1,1,4,6-tetramethylindane;
6,7-Diamino-1,1,4,5-tetramethylindane;
5,6-Diamino-1,1,4,7-tetramethylindane;
4,7-Diamino-1,1,5,6-tetramethylindane;
5,7-Diamino-1,1-dimethyl-4,6-diethylindane;
5,7-Diamino-1,1-dimethyl-4,6-diisopropylindane; and
5,7-Diamino-1,1,4-trimethyl-6-tert-butylindane;
The diaminoindane derivatives of this invention can be prepared by dinitrating indane derivatives and then reducing the dinitrated intermediates.
Indane derivatives useful as raw materials in the process of this invention can be prepared by reacting corresponding benzene derivatives with isoprene in the presence of an acid catalyst [P.W.K. Flanagan, et al.: The Journal of Organic Chemistry, 33(5), 2000-2008 (1968)].
Exemplary suitable indane derivatives for use in the process of the invention include
1,1-Dimethylindane;
1,1,4-Trimethylindane;
1,1,6-Trimethylindane;
1,1-Dimethyl-4-ethylindane;
1,1-Dimethyl-6-ethylindane;
1,1-Dimethyl-4-isopropylindane;
1,1-Dimethyl-6-isopropylindane;
1,1-Dimethyl-4-n-propylindane;
1,1-Dimethyl-6-n-propylindane;
1,1-Dimethyl-4-sec-butylindane;
1,1-Dimethyl-6-sec-butylindane;
1,1-Dimethyl-4-n-butylindane;
1,1-Dimethyl-6-n-butylindane;
1,1-Dimethyl-4-tert-butylindane;
1,1-Dimethyl-6-tert-butylindane;
1,1,4,6-Tetramethylindane;
1,1,4,5-Tetramethylindane;
1,1,5,6-Tetramethylindane;
1,1,4,7-Tetramethylindane;
1,1,6,7-Tetramethylindane;
1,1-Dimethyl-4,6-diethylindane; and
1,1,4-TrimethYl-6-tert-butylindane.
A mixture of isomers formed from the reaction between a benzene derivative and isoprene is used in many industrial applications.
To prepare dinitroindane derivatives as intermediates from these raw materials, the raw materials are dinitrated with a conventional nitrating agent. A mixed acid, fuming nitric acid, nitric acid-acetic acid or any other suitable known nitrating agent can be used as the nitrating agent. Mixed acid or fuming nitric acid is preferably employed. When fuming nitric acid is used as a nitrating agent, 80-98% nitric acid may be used in a molar amount of from about 3 to about 12 times the indane derivative. When a mixed acid is used, it may be formed of a combination of nitric acid or a nitrate such as sodium nitrate or potassium nitrate and concentrated sulfuric acid. The indane derivative, nitric acid or a nitrate and concentrated sulfuric acid may be used in a molar ratio of from about 2.2 to about 5 mole of nitric acid or nitrate and from about 1 to about 5 mole of concentrated sulfuric acid per mole of indane derivative.
The dinitration reaction may be conducted in a reaction solvent as needed. Suitable exemplary reaction solvents include halogenated hydrocarbon solvents such as methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, chloroform, carbon tetrachloride, 1,1,2,2-tetrachloroethane and trichloroethylene.
The reaction temperature may be about 5° C. or lower, preferably in from about -30° C. to about 5° C. more preferably in a range of from about -20° C. to about 0° C.
If the reaction temperature is too low, the dinitration proceeds slowly and it is difficult to bring the dinitration to completion. On the other hand, unduly high reaction temperatures result in an extreme increase of byproducts, for example, due to oxidation of the methylene groups of the indane derivative, thereby leading to a lowered yield. Such unduly low or high temperatures are hence not preferred.
Dinitration at a temperature of about 5° C. or lower inhibits side reactions, whereby the diaminoindane derivatives of the invention can be prepared in a high yield.
The dinitration reaction can be effected by any suitable method, for example, by adding the indane derivative dropwise into the nitrating agent or by adding the nitrating agent dropwise into the indane derivative. When a mixed acid is used, the nitration reaction can be conducted, for example, by using the mixed acid prepared in advance or by mixing the raw material with one of the acids and then adding the other acid into the mixture.
After completion of the reaction, the reaction mixture is diluted with ice water to separate a powdery or oily substance. The substance is collected by filtration or is extracted with a solvent and then concentrated, whereby the dinitroindane derivative is obtained as an intermediate. When the dinitration reaction is conducted using a solvent, the reaction mixture separates into two layers provided that the reaction mixture is diluted with water after the reaction. It is hence only necessary to separate and concentrate the oil layer.
The dinitroindane derivative obtained by the above dinitration reaction is then reduced to obtain the corresponding diaminoindane derivatives of the invention.
No particular limitation is imposed on the method for reducing the dinitroindane derivative. Various methods adapted to reduce nitro groups into amino groups may be employed. Catalytic reduction is however most preferred from the industrial viewpoint.
Exemplary reducing catalysts suitable for the catalytic reduction include metal catalysts employed routinely for catalytic reduction, for example, nickel, palladium, platinum, rhodium, ruthenium, cobalt, copper, and the like. Use of a palladium catalyst is preferred from the industrial viewpoint.
These catalysts may be used in a metal form. However, they are usually employed in a form carried on the surface of a carrier such as carbon, barium sulfate, silica gel, alumina or celite or as Raney catalysts with nickel, cobalt, copper or the like.
No particular limitation is imposed on the amount of the catalyst to be used. It is preferable that the catalyst be employed in an amount of from about 0.01% to about 10% metal by weight based on the weight of the intermediate dinitroindane derivative. More preferably, when used in a metal form, the catalyst is employed in an amount of from about 2% to about 8% by weight, and in an amount of from about 0.1% to about 5% by weight when borne on a carrier.
No particular limitation is imposed on the reaction solvent providing that the solvent is inert to the reaction. Exemplary suitable solvents include alcohols such as methanol, ethanol and isopropyl alcohol; glycols such as ethylene glycol and propylene glycol; ethers such as ethyl ether, dioxane, tetrahydrofuran and methylcellosolve; aliphatic hydrocarbons such as hexane and cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; esters such as ethyl acetate and butyl acetate; halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2-trichloroethane and tetrachloroethane; and N,N-dimethylformamide. Alcohols, glycols and ethers may also be employed. When a reaction solvent which is immiscible with water is used, and the reaction velocity is slow, the reaction can be caused to proceed faster by adding a conventional phase transfer catalyst such as a quaternary ammonium salt or quaternary phosphonium salt.
The solvent is employed in an amount sufficient to suspend the intermediate or completely dissolve the same. Preferably, the solvent is employed in an amount from about 0.5 to about 10 times by weight of the intermediate.
Generally, the reaction is carried out at a temperature of from about 20° C to about 200° C, preferably from about 20° C to about 100° C. The reaction pressure is generally from about normal pressure to about 150 atm.
The catalytic reduction is generally conducted by adding the catalyst to a solution or suspension of the intermediate and then introducing hydrogen under stirring at a prescribed temperature. The end of the reaction can be determined from the amount of hydrogen absorbed or by means of thin-layer chromatography or high-performance liquid chromatography.
After completion of the reaction, the target product can be obtained by removing the catalyst and the like employed for the reduction, concentrating the filtrate and then allowing it to deposit as crystals. As an alternative, the target compound can also be isolated by distilling the filtrate.
The diaminoindane derivatives prepared in accordance with the process of this invention are often obtained as mixtures of isomers depending on the type of indane derivatives employed as raw material. Diaminoindane compounds derived respectively from an unsubstituted 1,1-dimethylindane, mono-substituted derivatives of 1,1-dimethylindane and a di-substituted derivative of 1,1-dimethylindane in accordance with the process of this invention were fractionated by silica gel column chromatography and their chemical structures were identified by NMR analysis. The following results were obtained.
From unsubstituted 1,1-dimethylindane, a composition was obtained containing a small amount of 4,7-diamino-1,1-dimethylindane in addition to 4,6-diamino-1,1-dimethylindane and 5,7-diamino-1,1-dimethylindane. The yields of orthodiamine compounds were very small and thus were ignorable.
One to three isomers were formed from a monosubstituted 1,1-dimethylindane. From 1,1,4-trimethylindane, 5,7-diamino-1,1,4-trimethylindane was obtained. Orthodiamine compounds were observed only in extremely trace concentrations. From 1,1,6-trimethylindane, a composition consisting of 5,7-diamino-1,1,6-trimethylindane, 4,7-diamino-1,1,6-trimetylindane and 4,5-diamino-1,1,6-trimethylindane was obtained.
Only one diamine compound was obtained from a di-substituted 1,1-dimethylindane. From 1,1,4,6-tetramethylindane, 5,7-diamino-1,1,4,6-tetramethylindane was obtained.
This invention will be further clarified by the following examples, which are intended to be purely exemplary of the invention. Example 1
A reaction flask fitted with a stirrer, a thermometer and a condenser was charged with 300 g (2.82 mol) of m-xylene. The content was cooled to -15° C, to which 165 g (1.56 mol) of 93% sulfuric acid was added dropwise. A mixture of 68 g (1.00 mol) of isoprene and 150 g (1.41 mol) of m-xylene was then added dropwise over 7 hours while maintaining the reaction temperature around -10° C. The resultant mixture was stirred for additional 1 hour at the same temperature. After completion of the reaction, the reaction mixture was left over and the resulting sulfuric acid layer was removed. The organic layer was added with 300 g of 20% saline, followed by neutralization with aqueous ammonia. The mixture was heated to 70-80° C. and the resulting water layer was removed. Excess m-xylene was distilled off under reduced pressure. The thus-obtained residue was distilled under reduced pressure to obtain 1,1,4,6-tetramethylindane as a colorless liquid.
Yield: 120 g (69%).
Boiling point: 105-106° C. (16 mmHg).
1 H-NMR (CDC1 3 ,TMS) δppm:
1.25 (6H, s, 1-Me ×2),
1.90 (2H, t, 2-CH 2 ),
2.21 (3H, s, 4-Me or 6-Me),
2.31 (3H, s, 4-Me or 6-Me),
2.72 (2H, t, 3-CH 2 ),
6.77 (2H, s, 5-H and 7-H).
One hundred twenty grams (0.688 mol) of the 1,1,4,6-tetramethylindane thus obtained were added dropwise to a mixture of 101 g (1.5 mol) of nitric acid having a specific gravity of 1.52, 417 g (4.17 mol) of 98% sulfuric acid and 300 g of 1,2-dichloroethane, which had been cooled to -5° C. in advance, over 2 hours while maintaining the reaction temperature within a range of from -5° C to 0° C. After the addition, the contents were stirred for additional 1 hour at the same temperature. After completion of the reaction, 400 g of water were added to the reaction mixture under cooling to dilute the sulfuric layer. The resultant mixture was allowed to stand to form an organic layer. The organic layer was separated and then 500 g of water were added. 1,2-Dichloroethane was distilled off as an azeotropic mixture. Deposited crystals were collected by filtration, washed with water and then dried to obtain 5,7-dinitro-1,1,4,6-tetramethylindane as pale yellow crystals.
Yield: 175 g (96%).
Melting point: 91-93° C. 1 H-NMR (CDC 3 , TMS) δppm:
1.38 (6H, s, 1-Me×2),
2.08 (2H, t, 2-CH 2 ),
2.20 (3H, s, 4-Me or 6-Me),
2.28 (3H, s, 4-Me or 6-Me),
2.87 (2H, t, 3-CH 2 ).
Elemental analysis:
______________________________________ C H N______________________________________Calculated (%): 59.09 6.10 10.60Found (%): 59.03 5.86 10.52______________________________________
One hundred seventy-five grams (0.662 mol) of the 5,7-dinitro-1,1,4,6-tetramethylindane thus obtained were dissolved in 500 g of methanol, and after addition of 17.5 g of 5% Pd/C (water content: 50%) to the resultant solution, the mixture was stirred at 50-60° C. for 84 hours in a hydrogen gas atmosphere. After completion of the reaction, the reaction mixture was filtered and the filtrate was concentrated under reduced pressure. The thus-obtained residue was distilled under reduced pressure to obtain 5,7-diamino-1,1,4,6-tetramethylindane as pale yellow crystals.
Yield: 124 g (92.1%).
Melting point: 77-78.5° C.
Boiling point: 148-150° C. (3 mmHg).
1 H-NMR (CDC1 3 , TMS) δppm:
1.38 (6H, s, 1-Me×2),
1.86 (2H, t, 2-CH 2 ),
1.99 (3H, s, 4-Me or 6-Me),
2.03 (3H, s, 4-Me or 6-Me),
2.73 (2H, t, 3-CH 2 ),
3.3-3.5 (4H, br. s, NH 2 ×2).
Elemental analysis:
______________________________________ C H N______________________________________Calculated (%): 76.42 9.87 13.71Found (%): 75.61 10.25 13.95______________________________________
EXAMPLES 2-4
From benzene, toluene and isopropylbenzene, the corresponding indane compounds were prepared, respectively. They were separately dinitrated and reduced in a similar manner to Example 1, whereby diamines having the diamine skeletons shown respectively in Table 1 were obtained.
TABLE 1__________________________________________________________________________Indane compoundComposition Diaminoindane Molar Yield.sup.1 Composition.sup.2Ex. Compound ratio (%) Compound Ratio m.p. b.p.__________________________________________________________________________ (°C.)2 1,1-Dimethylindane 10 92.0 4,6-Diamino-1,1-dimethylindane 47.8 80-89 127-130/ 4,7-Diamino-1,1-dimethylindane 14.5 (1 mmHg) 5,7-Diamino-1,1-dimethylindane 37.73 6-Methyl-1,1-dimethylindane 7 94.6 4,7-Diamino-1,1,6-trimethylindane 16.5 60-77 147.5-150/ 4-Methyl-1,1-dimethylindane 3 5,7-Diamino-1,1,6-trimethylindane 48.6 (4 mmHg) 4,5-Diamino-1,1,6-trimethylindane 9.2 5,7-Diamino-1,1,4-trimethylindane 25.74 6-Isopropyl-1,1-dimethylindane 9 94.5 4,7-Diamino-6-isopropyl-1,1-dimethylindane 8.9 81-91 158-161/ 4-Isopropyl-1,1-dimethylindane 1 5,7-Diamino-6-isopropyl-1,1-dimethylindane 75.8 (5 mmHg) 4,5-Diamino-6-isopropyl-1,1-dimethylindane 18.7 5,7-Diamino-4-isopropyl-1,1-dimethylindane 13.4__________________________________________________________________________ .sup.1 Yield based on the starting indane compound. .sup.2 The composition is determined by means of H.sup.1NMR and highperformance liquid chromatography. .sup.3 The ratio is the area determined by means of highperformance liqui chromatography.
Application Example
Using the diamines obtained in Examples 1 and 3, respectively and commercially-available 4,4'-diaminodiphenylmethane, DETDA and t-BTDA, their reactivities as curing agents for urethanes were compared. Namely, 0.025 mol of each diamine compound was dissolved in dioxypropylene glycol to give 100 parts of a solution. The solution was then added with 0.01 g of dibutyltin dilaurate and further with 12.1 g of an isocyanate which was a prepolymer obtained by reacting a mixture of diphenyl methanediisocyanate and a carbodimidomodified derivative thereof with tripropylene glycol and having a NCO content of 26%. The resultant mixture was then stirred.
As an index representing the reactivity, the viscosity increase (loss modulus) was measured by a "RHEOMETER" (manufactured by Toyo Seiki Seisaku-Sho, Ltd.) immediately after conducting the above stirring for 5 seconds.
The results are diagrammatically depicted in FIG. 1.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
|
The invention relates to diaminoindane derivatives represented by the following formula: ##STR1## wherein R 1 and R 2 are each selected from the group consisting of a hydrogen atom and a lower alkyl group having from 1 to 4 carbon atoms, and a process for preparing same.
| 2
|
This is a division of application Ser. No. 601,873, filed Aug. 4, 1975, now U.S. Pat. No. 4,023,949.
FIELD OF THE INVENTION
The field of art to which the invention pertains includes the field of air conditioning, more specifically the field of evaporative refrigeration.
BACKGROUND AND SUMMARY OF THE INVENTION
Evaporative air conditioners have found use in localities where there is a sufficient difference between the dry bulb temperature and the corresponding wet bulb temperature to provide a desirable heat transfer gradient without need for altering the moisture content of the useful air or for resorting to vapor compression refrigeration. For example, if the dry bulb temperature is 93° F and the corresponding wet bulb temperature is 70° F, there is a difference of 23° F available for air conditioning operation. Early coolers operated by evaporating water directly into the useful air, thereby increasing its moisture level, but subsequent coolers have been based on the fact that the occupants of an enclosure will experience a greater degree of comfort by cooling the air of the enclosure while maintaining, or reducing, its moisture content.
A variety of sophisticated designs have been proposed and utilized wherein the heat absorptive action of evaporation is employed to reduce the temperature of heat exchange apparatus and in which air is then passed through the apparatus for the purpose of cooling. The air that is used for effecting the evaporation (working air) is conducted to the outside of the room to be cooled and the air that is cooled by passing through the apparatus (useful air) is directed into the room. In this way, the heat abstracted from the liquid during the evaporation is not redelivered to the air of the room, nor is the moisture content of the useful air increased. In this regard, one can refer to the following U.S. Pat. Nos. Re. 17,998, 2,044,352, 2,150,514, 2,157,531, 2,174,060, 2,196,644, 2,209,939, 2,784,571 and 3,214,936. Additional patents of interest are: U.S. Pat. Nos. 1,542,081, 2,488,116 and 3,025,685. In more recent years, evaporative coolers have been replaced by vapor compression refrigeration units in which refrigerant fluid is alternately compressed and evaporated in a refrigeration cycle. Such units can be made quite compact, but are generally inefficient and, importantly, energy-intensive. Dwindling energy resources have required priorities in this regard to be reexamined and the need for improved, more efficient cooling devices has become evident.
The present invention satisfies the foregoing need in that it provides a highly efficient apparatus for cooling of air. The device operates more efficiently by a conjunction of features. Specifically, a heat exchanger is used that separates its dry and wet sides; evaporating water is kept separate from the useful air so that cooling is performed without the addition of water vapor to the useful air. Additionally, the major portion, preferably all, of the working air, is drawn from the load; i.e., the working air is recirculated from the enclosure to be cooled to the wet side of the heat exchanger. Furthermore, in a preferable mode of construction, the wet side of the heat exchanger operates by movement of the working air internally through conduits countercurrently to water flowing downwardly therethrough along the conduit inner surfaces, while the useful air passes through the dry side externally across the conduits.
Specific constructional details for maximum efficiency are given hereinafter. In a specific embodiment, additional increases in efficiency can be obtained by flowing the moisture-laden return air exhausting from the wet side of the heat exchanger in heat-exchange, but separated, relationship with fresh air flow upstream from the dry side of the heat exchanger. In a further embodiment, a composite, hybrid system is provided in which a minor portion only of the useful air, downstream of the dry side of the heat exchanger, is passed over the evaporator of a vapor compression refrigeration system. A sufficiently small amount of the useful air can thus be cooled sufficiently below its dew point to dehumidify that portion of the air resulting in a greater reduction in the dry bulb temperature of the useful air. Other features are provided which, while decreasing somewhat from the total efficiency of the basic system, provide a greater degree or rate of cooling than heretofore possible with evaporative coolers for specialized applications and/or for high cooling rate usage. In this regard, a particular embodiment calls for a portion of the returned air to be diverted to mix with the fresh air for further cooling by the heat exchanger. In another particular embodiment, useful under certain climatic conditions to provide a lower temperature but at higher energy levels, a portion of the cooled useful air emerging from the heat exchanger is diverted to mix with the working return air for countercurrent contact with the evaporating water.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic "circuit" diagram of an evaporative cooler system embodying basic concepts of the present invention;
FIG. 2 is a diagrammatic elevational view of a specific embodiment of the system of FIG. 1;
FIG. 3 is a plan view of a portion of the heat exchanger tube array and header, taken on line 3--3 of FIG. 2;
FIG. 4 is an enlarged view of a portion of FIG. 3 below the header; and
FIG. 5 is a diagrammatic elevational view of a hybrid evaporative cooler system which incorporates the components of a vapor compression refrigeration unit.
DETAILED DESCRIPTION
As required, detailed illustrative embodiments of the invention are disclosed herein. The embodiments exemplify the invention and are currently considered to be the best embodiments for such purposes. However, it is to be recognized that the units may be constructed in various other forms different from that disclosed. Accordingly, the specific structural details disclosed are representative and provide a basis for the claims which define the scope of the present invention.
As above-indicated, the present evaporative refrigeration system is one in which the evaporating water is kept separate from the cooling air stream by means of a heat exchanger so that cooling is performed without the addition of water vapor, achieving sensible cooling. To effect the maximum cooling available at the lowest energy cost, at least a major portion, preferably all, of the working air used for the wet side of the apparatus is drawn from the room to be cooled (load), because it has a lower wet bulb temperature than outside, fresh air and thus a larger temperature differential can be obtained than if fresh air were used for that purpose. It is also preferred that the major portion of useful air, i.e., air passing through the dry side of the heat exchanger, be fresh air. A particularly useful form of apparatus to accomplish the foregoing is one utilizing an array of spaced vertically directed hollow elongated tubular members. The wet side is accomplished by gravity flow of water downwardly along the inner surfaces of the tubes in conjunction with countercurrent flow of returned air from the load, to exhaust. The dry side is accomplished by fresh air flowing in thermal conductive contact with the outer surfaces of the tubular members for cooling thereof, the cooled fresh air being delivered to the enclosure.
Referring to FIG. 1, there are illustrated various air flow paths which can be utilized by the present embodiment. The system includes a heat exchanger 10 through which fresh air 12 passes on the dry side emerging as two streams 14 and 16 of cooled useful air for flowing to two different zone locations 18 and 20, respectively, of an enclosure 22 to be cooled. A stream of return air 24 is flowed back to the heat exchanger 10 and constitutes a working fluid for evaporation of water within the heat exchanger 10, as will be described in more detail hereinafter. The moisture-laden return air exits as an exhaust stream 26, which, in a particular embodiment, is flowed in heat exchange relationship, as indicated at 28, with the fresh air 12 before being disposed exteriorly of the device and of the enclosure.
In accordance with a particular variation of operation, a portion of the return air can be diverted as a recirculation stream 30 to mix with the fresh air 12. By such means, the enclosure can be cooled more quickly than otherwise, although at a higher energy cost. In accordance with other variations of operation, portions of the cooled air streams 14 and 16 can be diverted as a by-pass streams 32 and 34, respectively, to mix with the working return air stream 24, passing through the wet side of the heat exchanger 10. Such a configuration is useful under certain climatic conditions to enable a lower temperature, but again at a higher energy cost.
Referring now to FIG. 2, the heat exchanger 10 comprises an array of spaced vertically directed hollow elongated tubular members 36 stacked between top and bottom header 38 and 40, respectively, so as to form a dry side enclosure 42 bounded on top and bottom by the headers 38 and 40, on the downstream side by a side wall 44 and on the upstream side by a filter 46. The side wall 44 is spaced sufficiently from the array of tubular members 36 so as to accommodate therein a pair of blowers 48 and 50. The blowers 48 and 50 are shown stacked one above the other, but may be disposed laterally adjacent each other. They draw fresh air 12 via ductwork 52 through the filter 46, past the external surfaces of the tubular members 36 in the dry side 42 of the heat exchanger, where the fresh air is cooled, and then distributes the cooled air to ductwork 54 and 56, opening into the enclosure 22, as the separate cooled air streams 14 and 16 referred to above. It is preferred to draw, rather than push, the useful air through the heat exchanger as such provides the most uniform air distribution without recourse to baffles, static plates or other such devices which would introduce additional resistance to airflow in the system. By using a pair of blowers 48 and 50, the cooled air can be passed to spaced zones 18 and 20 in the enclosure 22. The blowers 48 and 50 are variable speed blowers which are independently controlled by their own thermostats 58 and 60 located as desired respective the enclosure zones 18 and 20 to be cooled.
Ductwork 62 communicates with the enclosure 22 at 64 and conveys return air 24 to a blower compartment 66 in which a return air blower 68 pushes the return air into a plenum 70. The plenum 70 is disposed below and in communication with the interior surfaces of the tubular members 36 and is separated from the dry side of the heat exchanger by means of the bottom header 40. The plenum 70 also serves as a sump for containing a reservoir of water 72 for evaporation. The water 72 is fed by means of a water pump 74 and a suitable pipeline 76 to an array of manifold tubes 78 overlying the top header 38. The water 72 emerges from jets 80 in the manifold tube array 78 onto the top header 38 flowing into and downwardly along the inner surfaces of the tubular members 36, by the force of gravity, returning to the plenum 70 and reservoir of water 72 therein. The blower 68 pushes the working return air 24 upwardly through the tubular member 36 countercurrently to flow of the water 72, resulting in evaporation of a portion of the water 72, thereby abstracting heat from the walls of the tubular members 36. The moisture-laden air is discharged as an exhaust stream 36 from the top of the heat exchanger where it is conducted by ductwork 82 to a point of discharge 84. The ductwork 82 is formed with an annular section surrounding the fresh air ductwork 52 to provide a heat exchange assembly 28 to pre-cool the fresh air 12.
Although the return air 24 is shown as being pushed through the wet side of the heat exchanger by the blower 68, an alternative, somewhat more efficient, arrangement is to mount the blower at the top of the heat exchanger to draw the moist air through the wet side and into the ductwork 82.
Referring more specifically to the plenum 70, water which is not consumed in the evaporation process flows from the inner surfaces of the tubular members 36 and drips into the reservoir of water 72. The pump 74 can be a submersible pump as shown located within the reservoir of water 72, or can be external to the reservoir. Water is introduced into the plenum-sump region by means of a ball-float valve 86 connected to an input pipe 88. Scale and/or lime formations are minimized by use of a bleed-down system defined by a syphon 90. The syphon is located in the plenum, spaced just above the operational level of the reservoir 72 as determined by the ball-float valve 86 but below the level reached when operation of the unit is terminated. At that time, the reservoir water level will rise due to natural drain-back and the syphon 90 will cause a partial draining or bleed-down to expel contaminated water. Other methods of reducing contamination build-up, e.g., by means of a bleed line in the discharge line from the pump, can be used.
Other methods of water distribution than the manifold 78 can be used. For example, a trough network can be disposed over the top header 38 whereby water flows by gravity through notches in the sides of the troughs. Alternatively, a water trough system can be constructed integral with the top header 38 whereby the troughs would be disposed between the tubes and the water would flow from the troughs into and down through the tubes directly.
As earlier indicated, provision is made for recirculation of return air and for bypass of cooled air. With respect to the first provision, ductwork 92 leads from the return ductwork 62 to a region 94 adjacent the bottom of the fresh air filter 46. By such means, a portion of the return air 24 can be diverted, as shown at 98, to mix with the fresh air 12, thereby increasing the cooling rate. The amount of return air thus recirculated can be effected by means of a damper 100 disposed in the recirculation ductwork 92.
With respect to the second provision, ductwork 102 and 104 can be connected to the supply ductwork 54 and 56 to permit flow of bypass cooled air 32 and 34 therethrough to the return air blower compartment 66, regulated by dampers 106 and 108 (the lower portion of the ductwork 104 being hidden by the ductwork 102 in the view of FIG. 2). By such means a lower useful air temperature is achieved.
Details of construction of the array of tubular members 36 can be seen in FIGS. 3 and 4. The tubular members 36 are substantially square in external cross-sectional configuration, but are formed with substantially rounded corners. By using squared tubes, an array matrix can be obtained that permits greater external surface area than other configurations. The extent of spacing between the tubes is chosen so as to obtain a desired flow rate of fresh air on the dry side. Referring in particular to FIG. 4, in the specific configuration illustrated, the distance 110 between diagonally adjacent tubes is about twice the distance 112 between laterally adjacent tubes. In general, the distances chosen with respect to any particular size tubes should be such as to permit the desired flow rate in the free area between the tubes. Preferably, the external side dimension of each tube is greater than three times the external distance between laterally adjacent tubes and a ratio of about 5.6 is illustrated in FIG. 4. Referring again particularly to FIG. 3, a portion only of the header 38 is illustrated and the specific tubular array illustrated is comprised of 449 tubes arranged in 12 rows of twenty tubes each alternating with eleven rows of 19 tubes each. The particular tubes illustrated have a wall thickness of 0.03-0.04 inch. With the specific array illustrated, and an external side dimension of 1.25 inch, lateral distance between tubes of 0.225 inch and diagonal distance between tubes of 0.45 inch, the air "sees" a dry side free area of 1.79 ft 2 .
Again referring particularly to FIG. 4, the inner surfaces of the tubes are formed with longitudinal grooves 114 which parallel the flow of water and wet side air. The grooves serve to draw and spread the water by capillary action to wet the inner tube surfaces, providing a uniform film to enhance evaporation.
An example of the operating efficiency of the specific apparatus of FIGS. 2-4, can be calculated for a particular enclosure. With the dampers 100, 106 and 108 closed, with a heat exchanger efficiency of 80%, with fresh air at 93° F dry bulb and 70° F wet bulb, after equilibrium conditions have been obtained, at 1680 feet per minute operation, the air supplied to the enclosure will be 71.6 ° F dry bulb. If the enclosure heat load is 30,000 BTU/hr. the air leaving the enclosure will be 80.8° F dry bulb and 66.2° F wet bulb, with an average room or enclosure condition of 76° F dry bulb at 58% relative humidity. If in place of return air from the load, one would use fresh air as the working air for the wet side of the heat exchanger (70° F wet bulb temperature) the resultant cooled enclosure would have an average dry bulb temperature of 74.6° F instead of 71.6° F. Accordingly, there is demonstrated the importance of using the return air as the working fluid on the wet side of the heat exchanger, as provided for by the present construction. Furthermore, while it is not possible to achieve 100% efficiency, an efficiency of as much as 90% can be achieved by an increase in the number of heat exchange tubes. Under such conditions, with the present type of construction, a useful air stream can be obtained having a dry bulb temperature of 67.8° F.
The foregoing apparatus has a capacity of 30,000 BTU per hour and is comparable to a vapor compression refrigeration unit of about 37.500-42,800 BTU per hour total capacity (3-3.5 tons). Vapor compression refrigeration units have inherent limitations in the sensible capacity of their cooling coils (between 70 and 80%) whereas an evaporative cooler of the present construction is totally sensible. Furthermore, a comparative vapor compression refrigeration unit would require power consumption of from 4 to 8 killowatts whereas the above illustrated evaporative cooler has a power consumption of about 1 to 1.5 kilowatts.
Referring now to FIG. 5, as a further embodiment of the invention, a composite hybrid system is illustrated in which a portion of the cooled air stream is further cooled by heat exchange with the evaporator of a vapor compression refrigeration unit. Otherwise, the system is substantially the same as that illustrated in FIG. 2 except for the ommission of the heat exchange ductwork, the lateral disposition of the dry side blowers (one of which 48' only is shown) and resultant modification of configuration of the associated ductwork 102' and 104'. In this hybrid embodiment, the vapor compression refrigeration unit is defined by a compressor 116 connected by appropriate refrigerant line tubing 118 to a condenser coil 120 which in turn is connected by refrigerant line tubing 122 to an evaporator coil 124 connected via refrigerant line tubing 126 back to the compressor 116. The evaporator coil 124 is disposed in the dry side compartment of the heat exchanger downstream of the tubular members 36' so as to operate in the lowest possible air temperature region within the apparatus. Only a minor portion, preferably less than 25%, of the cooled air leaving the heat exchanger is contacted by the evaporator coil 124 so that a sufficient drop in temperature is accomplished in that portion of the cooled air stream to fall below the dew point. If the entire air stream were to pass by the evaporator coil, the drop in temperature would be insufficient to reach the dew point, but with only small amount of the air being so processed, the dew point is passed and the air is dehumidified. For example, in processing 14% of the cooled air past the evaporator coil 124, a dry bulb reduction of 3.8° F can be obtained compared to operation without dehumidification.
The moisture removed from the air, which in the example, is at approximately 53° F, is collected at the base of the evaporator coil 241 and drained to the plenum region 70', by means of an evaporate collection tube 128. The evaporate water will be of lower temperature than the wet bulb temperature of the wet side air and will therefore further enhance the performance of the unit. Since the pressure at the wet side is higher than that of the dry side, a "p-trap" 130 is formed at the end of the evaporate collection tube 128, to prevent blow-back of the condensed moisture into the dry side. By removing some of the moisture from the useful air, the wet bulb temperature is further reduced, so that after circulating through the enclosure or load, it is recirculated back to pass through the wet side of the heat exchanger as working air with a lower web bulb temperature, thereby cooling the heat exchanger tubes toward that lower temperature by evaporating the water on the wet side. This increases the effectiveness of the heat exchanger resulting in a further depression of the dry bulb temperature of the incoming useful air on the dry side. In the example presented herein, this additional cooling effect reduces the average enclosure temperature an additional 1° F.
As a further aid to operation and economy, the condenser coil 120 is disposed in the discharge path of the wet side of the heat exchanger. Accordingly, the condensing process takes place in an air stream of 65° F as opposed to the outside air temperature of 93° F. The combination results in significant reductions in energy required to operate the vapor compression refrigeration unit, resulting in a power requirement of only 50% of normal.
|
Air is evaporatively cooled by water in which the evaporating water is kept separate from the useful air (cooled air stream) by means of a heat exchanger so that cooling is performed without the addition of water vapor to the useful air, and in which the working air, absorbing the water vapor, is drawn from the load. A heat exchanger is disclosed which operates by movement of the working air internally through tubular conduits countercurrently to water flowing downwardly on the inner surfaces thereof while the air to be cooled passes externally across the conduits.
| 5
|
FIELD OF THE INVENTION
The present invention relates generally to devices for producing asphaltic product, and more particularly to an apparatus for processing recycled asphalt paving material.
BACKGROUND
For at least the past 15 to 20 years, it has been known to incorporate recycled asphalt pavement (RAP) with various quantities of virgin aggregate material to produce a desirable and consistent blend for resurfacing roads. To produce such blends, the challenge for manufacturers has been to create a production unit that addresses the problems currently associated with the production of RAP, namely: (1) the generation of environmental pollutants; and (2) the production of by-products which adversely affect the life expectancy of the equipment used in the plants. In addition, it is always desirable to design the system so that a minimum amount of energy is required, and production costs are thereby minimized. The above concerns are particularly significant when RAP is added in percentages of 20% or more. For example, the by-products and pollutants created by combining cold RAP with superheated virgin aggregate causes hydrocarbons and steam which chokes the filtering system of the main plant which in turn wreaks havoc with pressures in the baghouse and static pressure in the combustion chamber resulting in lower production rates.
The superheating of virgin aggregate also creates a volatile situation in drum mix plants because as the higher percentages of recycle are being incorporated into the hot mix asphalt, the virgin aggregate material (VAM) temperature must be raised, often above the flash point of the liquid asphalt cement (AC), in order to reach the job specified mix temperature.
In batch plants the enormous amount of steam created by combining the RAP, the VAM and the liquid AC in the mill may cause an explosion which destroys the properties of the virgin liquid AC while creating hydrocarbons which cannot be recaptured and are thus released into the atmosphere.
Various artisans have attempted to address the problems associated with asphalt recycling facilities. For example, U.S. Pat. No. 4,600,379 to Elliott discloses a drum heating and mixing apparatus having two, concentric drums that heat aggregate material first in the inner drum and then in the space between the inner and outer drums. An exhaust gas outlet duct operatively connects the exhaust gas from the inner drum to the atmosphere, while an exhaust gas feedback siphons gas emitted in the space between the drums for incineration through the system burner. In the Elliott system only some of the hydrocarbons are returned to the drum drying burner so that the volume of steam and hydrocarbons produced by the system is not being totally captured. At higher rates of RAP therefore, the system, if not choked off, will vent into either the atmosphere or the filter house, potentially causing the filter house bags to clog.
U.S. Pat. No. 5,090,813 to McFarland and U.S. Pat. No. 5,201,839 to Swisher each include a step to take at least some of the moisture out of the RAP before it is added to the VAM. A parallel dryer is used with a portion of the area set aside for preheating the RAP. Total air for the system is supplied by one exhaust fan thus gases created by both dryers must pass through the filter house. The area set aside for preheating the RAP is approximately one quarter of the total area of both the RAP and mixing dryer and the counterflow aggregate dryer. Therefore chamber temperatures tend to reach undesirable heights because of the rate at which the RAP drying burner must operate in order to raise the temp of the RAP. Total moisture removed from the RAP cannot be established before introduction of the RAP to the VAM.
U.S. Pat. No. 5,251,976 to Milstead is directly related to RAP being introduced in the Hot Elevator of the batch type plant and a diversion chute booting into designated hot bin #1. The percentages are normally controlled in much the same way a blending control is used on the drum mix type plants. This type of operation limits the contractor of a batch plant to one type of mix at any one time. Unfortunately, both state and federal regulations prohibit this type of mixing method because the segregation of the RAP and VAM cannot be controlled. Also moisture from the RAP causes corrosion of the bins, screens, and the hot elevator in a short period of time.
U.S. Pat. No. 4,540,287 to Servas et al. discloses an apparatus which is used to combine RAP and VAM in a totally separate mixing drum with liquid AC and all hydrocarbons and steam being directed to the main plant burner. Job specified mix temperature is established after mixing has been completed. Problems that have arisen on this apparatus are the ignition or flaming of the mix while trying to achieve desired temperatures; and when attached to a batch plant, again, as with almost all the previously discussed designs, the versatility of changing different types of mixes throughout the day is very limited.
A recent survey regarding asphalt recycling conducted by Future Technology Surveys of Lilburn, Ga., determined that the asphalt manufacturing industry is particularly concerned with: (1) a simple technology which will result in one piece of equipment that meets industry standards for processing recycle for both batch plant and drum mix operations; and (2) operating costs in running recycle. The present invention addresses both of those concerns.
SUMMARY OF THE INVENTION
Briefly describing one embodiment of the present invention, there is provided a recycled asphalt product (RAP) drying apparatus comprising a three-zone counterflow RAP dryer and a duct system to recycle essentially all of the hot gases back through the system. The three-zone RAP dryer has a combustion zone at one end, a drying zone at the other end, and a buffer zone between the combustion and drying zones. A RAP inlet to introduce RAP into the dryer is included at one end of the drying zone, and a RAP outlet to remove RAP from the dryer is included at the other end of the drying zone. A duct pathway routes hot air from the drying zone back to the buffer zone so that hot air may be recycled through the apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the basic RAP drying apparatus of the present invention, according to one preferred embodiment.
FIG. 2 shows the RAP drying system of the present invention, including the associated components.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to preferred embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the described device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
As briefly described above, the present invention is a RAP drying apparatus that operates more efficiently than prior art systems by recycling essentially all of the hot air produced by the burner. The apparatus includes a three-zone RAP dryer (including a combustion zone, a buffer zone and a drying zone) and a duct pathway to route hot air from the drying zone of the RAP dryer back to the buffer zone of the dryer. In one preferred embodiment the duct pathway routes hot air from the drying zone back to the combustion zone before further routing it to the buffer zone of the apparatus.
Referring to the drawings, FIG. 1 is a side elevational view of one preferred embodiment of the apparatus of the present invention. As shown in the Figure, RAP drying apparatus 10 includes RAP dryer 11 and duct pathway 12. A booster fan 13 and an inertial separator 14 are preferably included in duct pathway 12.
RAP dryer 11 has two ends, first end 11a and second end 11b. A drying zone 21 is located at the first end 11a of RAP dryer 11, and a combustion zone 23 is located at the second end 11b. A buffer zone 22 is positioned between drying zone 21 and combustion zone 23. A combustion burner 20 is provided at the second end 11b of the dryer (with the associated flame being confined to combustion zone 23) to provide heat to the dryer.
RAP charging chute 26, RAP discharge chute 27 and trickle chute 28 are also preferably included in the apparatus to facilitate the flow of RAP through the system.
A dryer motor 30 is preferably included to turn drying zone 21. RAP dryer 11 is of the counterflow type, which allows for either a counter clockwise or clockwise rotation. In one preferred embodiment the rotation is clockwise, viewing from the discharging end. The speed of the rotation is controlled by variable speed motor 30, which drives RAP dryer 11 and thereby regulates the rate of RAP flow through the dryer.
During HMA production, both RAP and aggregate dryers will run simultaneously, heating their respective material to desired materials. RAP dryer 11 is fed by a variable speed motor control from a recycle holding bin which shuttles the material up the recycle bin conveyor and assures that the desired amount of recycle necessary to maintain the correct recycle to virgin material mix percentages is dropped into the recycle charging chute 26. The material dropping from recycle charging chute 26 is then received by the RAP dryer veiling flights (not shown) so that the drying process can begin.
Material to be dried is heated by the hot air stream and continually veiled in a counterflow direction through the RAP dryer 11. Upon reaching discharge sweeps, the RAP exits the RAP dryer 11 through RAP discharge chute 27.
The hot air stream utilized in the drying process is created by burner 20, with the flame being contained in combustion zone 23. The hot air stream travels from the combustion zone 23 through buffer zone 22, before heating the RAP in drying zone 21.
After drying the RAP, the hot air is then pulled through duct pathway 12 for recirculation through the system. The hot air stream volume and velocity are controlled by booster fan 13, and by the various dampers preferably included in the system. In particular, dampers 34 and 35 are preferably included in duct pathway 12. A separator 14 captures any of the "fines" material in the air stream and sends the captured fines through the trickle valve chute 28 into the RAP discharge chute 27, thus blending the fines with the dried recycle before the recycle reaches the dry RAP conveyor.
Once the hot air stream has been purged of fines, it is then diverted to one of two ducts. The majority of the hot air stream passes through the reburn duct 41 back into the stationary buffer zone 22 to be reheated by the RAP combustion burner 20. Because the heat of the hot air stream is retained in RAP dryer 11, the air passing through the reburn duct 41 prevents the stationary combustion zone 23 from reaching the undesirable high temperatures usually associated with stationary combustion zones.
FIG. 2 shows certain components of the existing asphalt production facility with which the inventive apparatus is designed to work. For example, main plant duct 52, knock-out box 53, baghouse 55, exhaust fan 57 and exhaust stack 58 are shown. Preferably, the drying apparatus 10 is connected to the main plant equipment by dryer-to-plant duct 60.
If for any reason the hot air stream needs to be pulled at a greater rate, a louver damper 61 controlling the air flow to the main plant can be opened into the vented air stream which is contained in the RAP to main plant duct.
Also contained in the RAP-to-main plant duct is an isolation damper 52 which serves two purposes. First, this damper can be closed to isolate the RAP drying system from the main plant system when RAP is not required for the HMA. Second, in the event that the buffer zone scanners 65 should detect a flame, the isolation damper will automatically close to contain the flame in the RAP drying system.
Any minuscule amount of air that may need to be vented through the RAP to main plant duct will be carried through the main plant duct and processed through the main plant knock out box assuring that any of the RAP fines passing through the RAP to main plant duct are captured and taken to either a return screw conveyor or by pneumatic means to a fines silo. The purged air is taken to a filter house and any minute dust particles are collected on the filters, resulting in clean air being pulled by the exhaust fan and vented through the stack exhaust of the main plant.
The velocity and volume of the hot air stream is controlled automatically by the RAP booster fan louver damper maintaining the RAP dryer pressure as close as possible to positive which in turn creates a much more efficient drying environment than they typical aggregate drying process.
The desired discharge temperature of the finished RAP will be between 170 degrees and 180 degrees. The RAP thermocouple senses the temperature of the RAP discharge chute and sends the temperature reading to an automatic burner control. Should the temperature rise more than 20 degrees above the desired set point, the control will shut down the RAP combustion burner 20 insuring that no undesirable hydrocarbons can be produced and eliminating the chance that the RAP will reach its flash point.
Final product generated by the RAP drying process indicated in FIG. 1 is then taken by the dry rap conveyor and is either blended with the VAM in the RAP chute in the hot elevator and taken by the hot elevator 71 to the top of the batch tower or taken to an intermediate port and blended with the VAM in the designated mixing zone of the drum mix plant to produce the HMA.
As higher percentages of recycle are being incorporated into the HMA, the VAM temperatures must be raised, often times above the flash point of the liquid AC, in order to reach the job specified mix temperature. This invention will keep the virgin aggregate below the flash point while still sustaining the job specified mix temperature.
Further, the present invention will raise the recycle temperature allowing for the lowering of the VAM temperature which will, in turn, not only eliminate the explosion in the batch tower but will also eliminate the production of hydrocarbons.
Finally, the variable speed motor on the RAP dryer cuts down segregation, improving the quality of the mix and allowing deviations in drying time for various sizes and types of recycle.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
|
A recycled asphalt product (RAP) drying apparatus comprising a three-zone counterflow RAP dryer and a duct system to recycle essentially all of the hot gases back through the system. The three-zone RAP dryer has a combustion zone at one end, a drying zone at the other end, and a buffer zone between the combustion and drying zones. A RAP inlet to introduce RAP into the dryer is included at one end of the drying zone, and a RAP outlet to remove RAP from the dryer is included at the other end of the drying zone. A duct pathway routes hot air from the drying zone back to the buffer zone so that hot air may be recycled through the apparatus.
| 4
|
[0001] This application claims the benefit of Taiwan application Serial No. 101102922, filed Jan. 30, 2012, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates in general to a television system, and more particularly, to a technique for integrating heterogeneous operating systems in a television system.
[0004] 2. Description of the Related Art
[0005] As technology products and the Internet both expand and converge, types and quantity of resources including text, graphics, video clips, music and games acquirable by a user through the Internet have expanded at an overwhelmingly fast pace. Therefore, it is a common vision and trend to incorporate Internet resources into household or commercial multimedia systems that can then provide users with more convenient and versatile information entertainment platforms.
[0006] A principal part of a multimedia system is the television. Therefore, it is a goal of television system designers to effectively integrate resources and applications acquired through the Internet into a television system.
[0007] A key issue in the above integration is that, not all applications acquired through the Internet are compatible to an operating system of the television system. For example, an operating environment of a television system may be Linux, whereas an application acquired through the Internet is only suitable in an Android operating system. The Linux operating system and the Android operating system have a same kernel but different function libraries—the two operating systems are heterogeneous operating systems. In a situation where the operating environment or the application stays unmodified, the application cannot be executed in the television system.
[0008] To overcome the foregoing incompatibility issue, a common approach is to modify original source code of television system software, so that the modified source code can adapt to an application compatible to another operating system. However, such approach requiring substantial modifications to the source code of the television system software is not only time and effort consuming but also extremely difficult. Moreover, when further integration of different types of operating systems in the television system is desired, such an approach of modifying the source code of the television system software is almost infeasible. Therefore, flexibility and augmentation possibilities rendered by an Internet television achieved through the foregoing conventional solution are rather unsatisfactory.
SUMMARY OF THE INVENTION
[0009] The invention is directed to a television system, in which an application management module is utilized to allow applications of heterogeneous operating systems having different function libraries to be simultaneously displayed in a same display image and utilized without modifying source code.
[0010] According to one embodiment of the present invention, a storage medium disposed in a television is provided. Code of a television software system is stored in the storage medium. The television software system comprises a first application, a second application and an application management module. The first application has a first function library. The second application has a second function library different from the first function library. The application management module manages the first application and the second application according to the first function library and the second function library, respectively.
[0011] According to another embodiment of the present invention, a method for managing applications is provided. The method is applied to a television software system of the television. The television software system comprises a first application, a second application and an application management module. The method for managing applications comprises steps of: a) receiving a call for a target application; b) determining whether the target application is a focus application in the applications; and c) when the target application is not the focus application, sending a focus withdrawal command to the focus application and sending a focus assigning command to the target application. The above steps (a), (b) and (c) are performed by the application management module.
[0012] According to yet another embodiment of the present invention, a method for managing applications is provided. The method is applied to a television software system of the television. The television software system comprises a first application, a second application and an application management module. The method for managing applications comprises steps of: receiving a user command; determining by the application management module whether the user command is a hotkey command; determining by the application management module whether the hotkey command is disabled; when the user command is the hotkey command and the hotkey command is disabled, sending the user command to a focus application in the applications by the application management module; and when the user command is the hotkey command and the hotkey command is not disabled, sending the user command to a target application corresponding to the hotkey command in the applications by the application management module.
[0013] For a system designer, the television system structure according to the present invention offers an advantage that a main source code of a main operating system of a television system does not need to undergo substantial modifications for adapting to various operating system having different function libraries. In addition, by defining a common application interface and management mechanism, original source codes of applications compliant to different operating systems can be directly adopted such that a time and effort consuming porting procedure is not needed. For a user, the foregoing television system is capable of accommodating and integrating applications provided by various heterogeneous systems, thereby significantly enhancing augmentation possibilities and convenience.
[0014] The above and other aspects of the invention will become better understood with regard to the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1A is a block diagram of a television system according to one embodiment of the present invention.
[0016] FIG. 1B is a block diagram of a hardware structure of a television system according to one embodiment of the present invention.
[0017] FIGS. 2A to 2F are examples of an application management module coordinating activation, termination, focus switching and resource switching of applications according to one embodiment of the present invention.
[0018] FIG. 3 is an example of state changes of an application in a television system according to one embodiment of the present invention.
[0019] FIG. 4 is a flowchart of an application management module determining to which application the user command is to be transmitted according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] FIG. 1A shows a structure of a television system according to one embodiment of the present invention. Referring to FIG. 1A , a television system 100 comprises an application management module 10 , a main operating platform 20 , a television signal playback application 22 , a web-based software system application 24 , a flash-based software system application 26 , a local software system application 28 , and an Android operating system 30 . In this embodiment, software systems of the applications 22 to 28 and the Android system 30 correspond to a same kernel but have different function libraries, and may thus be regarded as heterogeneous software systems. In the following description, a Linux operating system is taken as an example for the main operating system 20 for explaining the embodiment rather than limiting the present invention.
[0021] FIG. 1B shows an exemplary hardware structure of the television system 100 . A central processor 61 executes various software applications in the system. A memory 62 is for temporarily storing data. A demultiplexer 63 decomposes a television signal into a video bitstream and an audio bitstream, and respectively provides the two bitstreams to a video decoder 64 and an audio decoder 65 . An output signal from the video decoder 64 is transmitted to the memory 62 , and is utilized by a scaler 66 and a graphic engine 67 . The graphic engine 67 generates an image of an on-screen display (OSD), a rendered game and/or various applications. The scaler 66 scales a video image to generate a video image suitable for a panel resolution. A sound-effect digital processor 68 receives the output from the audio decoder 65 to further generate various sound effects, e.g., a surround sound effect. A storage device 69 stores codes of the software applications required by the television system. For example, the storage device 69 is a hard disc or a flash memory. The storage device 69 may also be integrated in the memory 62 .
[0022] In practice, the video decoder 64 , the audio decoder 65 , the scaler 66 , the graphic engine 67 and the sound-effect digital processor 68 in FIG. 1B are system resources that the applications in FIG. 1A can request for use.
[0023] The application management module 10 manages applications of multiple heterogeneous software systems of the television system 100 according to function libraries of the software systems. More specifically, the application management module 10 is for managing applications installed in the television system 100 . In practice, functions of the television signal playback application 22 are not limited to playing television signals but may also process multimedia signals of other specifications. For example, the web-based application 24 is a web broadcasting playback application, the flash-based application 26 is an online video-playing application, and the local application 28 is a web call application.
[0024] The applications of the Android operating system 30 comprise at least one application, i.e., an Android application. For example, the Android application 34 is a game, a browser, a multimedia playback application, an interface widget, or other types of Android applications. In this embodiment, a framework of the Android operating system 30 comprises a launcher 32 capable of communicating with the application management module 10 . In practice, the launcher 32 may be modified from an inherent launcher in the
[0025] Android operating system 30 so that the launcher 32 becomes capable of communicating with the application management module 10 .
[0026] In this embodiment, the application management module 10 directly communicates with the applications 22 to 28 , and communicates with the Android application 34 via the launcher 32 . As shown in FIG. 1A , for example, the above communications (e.g., transmitting/receiving a request or a command) are performed through an inter-process communication (IPC) channel 40 . Referring to FIG. 1A , the applications 22 to 28 may respectively be regarded as a direct client of the application management module 10 , and communicate with the application management module 10 via an application interfaces (API) 80 provided by the application management module 10 . For the Android application 34 in the Android operating system 30 , the launcher 32 may be regarded as a direct client of the application management module 10 , and communicates with the application management module 10 via the API 80 provided by the application management module 10 . In contribution to the communication conversion function provided by the launcher 32 , the source code need not be modified to adapt to the main operating platform 20 of the television system 100 regardless of the type of the Android application 34 . On the other hand, the application management module 10 may also implement the same management mechanism (the same APIs 80 ) to control the applications 22 to 28 and the Android application 34 .
[0027] In one embodiment, after the various applications (e.g., the applications 22 to 28 and the Android application 34 in FIG. 1A ) are installed in the television system 100 , related information (e.g., names, graphics, software systems and execution paths) of the applications are collectively registered to an application definition file. The application management module 10 can learn what applications are installed in the television system 100 , and utilize the application definition file as a reference basis for managing the applications.
[0028] Further, a directory application compatible to the Linux operating system may be installed in the television system 100 . The directory application enumerates (e.g., through texts or graphics) the applications installed in the television system 100 for the reference of a user. For example, after being activated, the directory application can be presented as a graphic interface on a screen of the television system 100 to display all icons of the applications, so that a user is allowed to select an application to be activated or deactivated through a control device such as a remote controller or a mouse. The foregoing application definition file may also serve as an information source for the directory application. For example, the application management module 10 may be designed as to read the current application information from the application definition file each time when the television system 100 is turned on, and then provide the information to the directory application.
[0029] Referring to FIG. 1A , the television system 100 comprises a user interface 50 . In practice, the television system 100 may concurrently comprise different user control interfaces, e.g., a radio-frequency/infrared controller, panel buttons, a mouse and a keyboard. Thus, for example, the user interface 50 may correspondingly be a remote control signal receiver, a mouse signal receiver, a keyboard/button signal receiver, or an interface integrated with the above receiving functions. In this embodiment, a user command received by the user interface 50 is predetermined to be provided to a focus application in the applications, and is usually an application at an uppermost layer displayed on the screen.
[0030] As the user interface 50 receives the user command, the command is transmitted to the application management module 10 via the IPC channel 40 and is then processed by the application management module 10 . When the user command is determined as corresponding to one of the applications 22 to 28 , the application management module 10 directly forwards the command to the application via the IPC channel 40 . In contrast, when the user command corresponds to the Android application 34 , the application management module 10 transmits the command to the launcher 32 via the IPC channel 40 , and the command is then forwarded to the Android application 34 by the launcher 32 .
[0031] As previously stated, the application management module 10 is for managing the applications 22 to 28 as well as the application 34 . In practice, the so-called management may include activating/terminating an application, transferring a focus permission among applications, and coordinating system resources (e.g., display images, sound effects and networks) for requests and access permission of applications. That is to say, the application management module 10 manages the applications through a focus permission and a resource permission. In practice, since the applications are compliant to different software systems, the applications may respectively have dedicated a focus assigning function, a focus withdrawal function, a resource assigning function, a resource withdrawal function and a termination function. The application management module 10 can communicate with the applications according to the functions of the applications. Examples of the application management module 10 coordinating the activation, termination, focus switching and resource switching of the applications shall be given with reference to FIGS. 2A to 2F .
[0032] Referring to FIG. 2A , in this example, the user selects and activates a target application B via a directory application A. The target application B is originally in an activated state (e.g., being executed in the background) but is not a focus application. The directory application A sends a request for calling the target application B to the application management module 10 . Before transferring the focus to the target application B, the application management module 10 first sends a focus withdrawal command to an original focus application C, and sends a focus assigning command to the target application B to accordingly make the target application B as the new target application. In other words, after receiving a call directly to a target application, the application management module 10 first determines whether the target application is a focus application. When the target application is not the focus application, the application management module 10 sends a focus withdrawal command to an original application, and then sends a focus assigning command to the called target application.
[0033] Referring to FIG. 2B , in this example, the user similarly selects and activates the target application B via the directory application A. The target application B is originally in a deactivated state. After receiving the request for calling for the target application B from the directory application A, the application management module 10 first sends a focus withdrawal command to the original focus application C and then activates the target application B. In this example, a callback function list is transmitted to the application management module 10 by the target application B after the target application B is activated. A main function of the callback function list is to inform the application management module 10 which applicable functions and the expected function formats that are to be used for communicating with the target application B, and to simultaneously notify the application management module 10 that the activation procedure is successful. For example, the callback function list comprises a focus assigning function, a focus withdrawal function, a resource assigning function, a resource withdrawal function and a termination function. After receiving the callback function list, the application management module 10 sends a focus assigning command to the target application B according to the focus assigning function.
[0034] It is known from the two above examples that, after receiving the request for calling the target application B, the application management module 10 first determines whether the target application B is an application in execution, and the application management module 10 first activates the target application B when the target application B is not the application in execution. It should be noted that, in other embodiments, the foregoing callback mechanism is not necessary for communication between the application management module 10 and the applications. For example, function formats suitable for the applications may be stored in advance in the application management module 10 or in a periphery file. Since operation rules of the applications are different, an advantage of using the callback mechanism is that the application management module 10 is not required to pre-record the functions and operation rules of all the applications of the television system 100 .
[0035] Referring to FIG. 2C , in this example, an application D originally in execution in the background sends a request for becoming a focus application to the application management module 10 . Accordingly, the application management module 10 first sends a focus withdrawal command to the original focus application C, and then sends a focus assigning command to the application D. For example, the original focus application C may be the television signal playback application 22 , and the application D may be a web call application. In order to catch a user's attention, the web call application may be designed to request the application management module 10 to become a focus application presented at the uppermost layer of the screen upon receiving an incoming call message.
[0036] In an actual application, the request for transferring the focus from the original focus application C to the application D may be a forced-on request transmitted by the main operating system 20 . For example, the main operating system 20 activates the application D at a specific time point according to a predetermined condition defined by a user, and predetermines that application D becomes the focus application once the application D is activated.
[0037] Referring to FIG. 2D , in this example, an approach for coordinating the resource switching among the applications by the application management module 10 shall be explained. For example, the system resources of the television system 100 , e.g., the video decoder 64 , the audio decoder 65 , the scaler 66 , the graphic engine 67 , and the sound-effect digital processor 68 in FIG. 1B , are shared by all the applications. The application management module 10 may be adopted to coordinate the system resource requirements of the applications. When the application D sends a request for obtaining the audio/video processing resource to the application management module 10 , the application management module 10 first sends a resource withdrawal command to an original resource-using application E, and then sends a resource assigning command to the application D. In practice, the application management module 10 may determine to withdraw all or a part of the resource from the original resource-using application E based on actual circumstances. When the application D demands a sole access to the video/audio processing resource, the application management module 10 withdraws all the resource from the original resource-using application E. In addition, when the audio processing resource and the video processing resource of the television system 100 are independently operable, the application management module 10 may respectively assign the two types of resources to different applications.
[0038] Referring to FIG. 2E , in this example, the user selects and activates the target application B via the directory application A. The target application B is originally in a deactivated state, and the application management module 10 is aware that the video/audio processing resource is required for executing the target application B. After receiving the request for calling the target application B from the directory application A, the application management module 10 first sends a focus withdrawal command to the original focus application C, then sends a resource withdrawal command to the original resource-using application E, and then activates the target application B. As shown in FIG. 2E , after receiving the callback function list provided by the target application B, the application management module 10 sequentially sends a focus assigning command and a resource assigning command to the target application B according to the focus assigning function and the resource assigning function in the callback function list. In practice, the original focus application C and the original resource-using application E may be a same application.
[0039] Referring to FIG. 2F , a main difference between this example and the example in FIG. 2E is that, the target application B and the original resource-using application E in this example cannot coexist. Therefore, before activating the target application B, the application management module 10 first sends a termination command to the original resource-using application E. In other words, before activating the target application B, the application management module 10 first determines whether a current application conflicts with the target application B. When the current application conflicts with the target application B, the application management module 10 first sends a termination command to the current application and then activates the target application B. In practice, applications which conflict with the target application B may be recorded in the callback function list provided by the target application B to the application management module 10 , or may be recorded in the application definition file.
[0040] Deduced from the above examples, a state of an application of a television system 100 may be concluded as shown in FIG. 3 . Before being activated or terminated, an application is in a non-focus with no-resource state. The application management module 10 is in charge of activating or terminating an application, and also handles switching of a focus permission and a resource permission among applications. As previously described, when transmitting or receiving various types of commands from the applications, the application management module 10 directly communicates with the applications 22 to 28 , and communicates with the application 34 via the launcher 32 . For example, when the television signal playback application 22 needs a video/audio processing resource, the television signal playback application 22 directly sends a request to the application management module 10 . When the Android application 34 needs the video/audio processing resource, a request is sent to the application management module 10 via the launcher 32 .
[0041] In practice, in addition to the directory application A, the user may also send a command for activating, deactivating or adjusting operating parameters of a target application via a remote controller or a hotkey on a keyboard, and the target application is not necessarily a focus application. It should be noted that, when certain applications become a focus application having the focus permission, the applications disable hotkeys of other applications. This situation is to be taken into consideration when the application management module 10 forwards the user command received by the user interface 50 .
[0042] FIG. 4 shows a flowchart of the application management module 10 determining to which application the user command is to be transmitted according to one embodiment of the present invention. When receiving a user command transmitted from the user interface 50 , the application management module 10 first performs Step S 41 to determine whether the command is a hotkey request corresponding to a target application. When a result of Step S 41 is affirmative, the application management module 10 performs Step S 42 to determine whether the command is a disabled hotkey request (i.e., the hotkey disabled by a current focus application). When a result of Step S 42 is negative, the application management module 10 performs Step S 44 , in which the application management module 10 sends the user command to the target application. Conversely, when the result of Step S 41 is negative or when the result of Step S 42 is affirmative, the application management module 10 performs Step S 43 to send the user command to the focus application.
[0043] In practice, the application management module 10 may send the user command to a buffer corresponding to the target application or the focus application. In other words, each application in execution may be designed to correspond to a buffer for storing the user command. An advantage of storing the user command at a client end rather in the application management module 10 is that, overall system performance is maintained by preventing a client from periodically querying the application management module 10 whether there is a new user command.
[0044] In one embodiment of the present invention, an activation time of the main operating system 20 is earlier than an activation time of the Android operating system 30 , so that an effect of embedding a widget of the Android interface into a television image can be achieved.
[0045] Although only one application 34 is depicted in the operating system 30 , a plurality of applications compliant to the operating system 30 may be installed in the television system 100 . Under such conditions, the application management module 10 may still be designed to regard all the applications compliant to the operating system 30 as one single client, and communicates with the applications via the launcher 32 . For example, all focus transferring requests or resource requests coming from the applications compliant to the operating system 30 may be regarded as requests of the launcher 32 . According to a response from the application management module 10 received by the launcher 32 , the operating system 30 may determine how to assign the focus or how to distribute resources.
[0046] It is known from the above description that the operations and management method of the application management module 10 are suitable for the television system 100 comprising a plurality of heterogeneous software systems (e.g., the applications 22 to 28 as well as the Android operating system 30 ). The heterogeneous software systems may directly communication with the application management module 10 or may communicate with the application management module 10 via the launcher. In contrast, the application management module 10 may also regard the heterogeneous software systems as different clients that can be managed by a same management mechanism (e.g., a same application interface).
[0047] For a system designer, the television system structure according to the present invention offers an advantage that the main source code of the main operating system 20 of the television system 100 does not need to undergo substantial modifications for adapting to various software systems having different function libraries. In addition, by defining a common application interface and management mechanism, original source code of the applications compliant to different software systems can be directly adopted such that a time and effort consuming porting procedure is not needed. For a user, the foregoing television system is capable of accommodating and integrating applications provided by various heterogeneous systems, thereby significantly enhancing augmentation possibilities and convenience.
[0048] While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
|
A storage medium disposed in a television is provided. A code of a television software system is stored in the storage medium. The television software system includes a first application, a second application and an application management module. The first application has a first function library. The second application has a second function library different from the first function library. The application management module manages the first application and the second application according to the first function library and the second function library, respectively.
| 7
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a gear-mesh type automatic transmission system capable of controlling clutch on/off operation, i.e., operation for changing over the clutch between a meshing state (on-state) and a released state (off-state). More particularly, the present invention is concerned with an improvement of the gear-mesh type automatic transmission system such that shock which may take place upon coupling of the clutch in succession to changeover of speed stage in the gear-mesh type automatic transmission system can be suppressed or mitigated regardless of time-dependent deterioration (i.e., deterioration as a function of time lapse) of the clutch.
[0003] 2. Description of Related Art
[0004] Heretofore, there have been proposed and developed for practical applications a variety of gear-mesh type automatic transmissions employing gear-mesh type transmissions. By way of example, in the control apparatus for the gear-mesh type automatic transmission system disclosed in Japanese Patent Laid-Open No. 63-270252 (1988), the output torque or power of an engine such as an internal combustion engine is inputted to a gear-mesh type automatic transmission through coupling operation (on-operation) of an electromagnetic clutch.
[0005] Further, in the case of the control apparatus described in the publication cited above, combination of operations of a pair of hydraulic/electromagnetic valves is adopted. More specifically, selection of a desired or target speed stage is realized by driving or actuating correspondingly a selection-dedicated three position hydraulic cylinder while changeover to the selected speed stage is realized by actuating a three position hydraulic cylinder dedicated for the gear shift operation.
[0006] Further, as a conventional clutch control unit known heretofore, there may be mentioned one disclosed, for example, in Japanese Patent Laid-Open No. 60-35633 (1985). In this known clutch control apparatus, an electromagnetic clutch is so controlled that coupling thereof is carried out at a constant speed or rate. In that case, the clutch on/off performance of the apparatus will gradually change as a function of time lapse due to deterioration (abrasion) which the clutch undergoes during operation thereof.
[0007] Consequently, for a same clutch exciting current, there arises difference in the clutch coupling operation performance between a new electromagnetic clutch and a used one.
[0008] In particular, in the case where the clutch is coupled through a constant-speed control (open-loop control), there is a tendency that shock is more likely to take place upon coupling of the clutch in succession to speed stage changeover as the deterioration (abrasion) of the clutch gets aggravated even if occurrence of such shock can be controlled to be suppressed for the new clutch.
[0009] Furthermore, the clutch coupling force may differ from one to another electromagnetic clutch. Thus, for performing the open loop control mentioned above, it is necessary to determine in advance the clutch coupling speed in consideration of the intrinsic performance of the clutch to be employed so that the shock occurring upon clutch coupling operation succeeding to the speed stage changeover operation can be suppressed or mitigated at the least.
[0010] As is apparent from the foregoing, the conventional gear-mesh type automatic transmission system suffers a problem that shock may occur upon coupling of the clutch in succession to the speed changeover operation of the transmission due to the time-dependent deterioration such as abrasion of the clutch.
[0011] Further, for effectuating the open loop control, the clutch coupling speed has to be determined in advance in consideration of dispersion of the coupling force among the individual electromagnetic clutches so that occurrence of the shock upon clutch coupling operation succeeding to the speed stage changeover of the transmission can be suppressed, giving rise to another problem.
SUMMARY OF THE INVENTION
[0012] In the light of the state of the art described above, it is an object of the present invention to provide a gear-mesh type automatic transmission system capable of suppressing or mitigating shock which is likely to occur upon coupling of a clutch in succession to changeover of the speed stage regardless of time-dependent deterioration or abrasion of the clutch.
[0013] Another object of the present invention is to provide a gear-mesh type automatic transmission system capable of controlling the clutch coupling speed so as to mitigate shock which is likely to occur upon clutch coupling operation succeeding to changeover of the speed stage of the gear-mesh type transmission in spite of dispersion among individual clutches.
[0014] In view of the above and other objects which will become apparent as the description proceeds, there is provided according to a general aspect of the present invention a gear-mesh type automatic transmission system which includes a gear-mesh type transmission for outputting an output power of an engine at a selected gear ratio, an electromagnetic clutch for effectuating transmission and interruption of the output power from an output shaft of the engine to an input shaft of the gear-mesh type transmission, a shift/select actuator for shifting a speed change gear to a shift/select position in the gear-mesh type transmission, a shift/select position sensor for detecting a shift/select position of the speed change gear in the gear-mesh type transmission, and a control unit for driving the shift/select actuator in accordance with a shift lever position selected by a driver while monitoring the shift/select position, to thereby change over automatically the gear-mesh type transmission to a desired speed stage, wherein the control unit is so designed as to couple the electromagnetic clutch by controlling through a feedback loop a rate of change of a slip rotation speed determined as difference between rotation speed of the engine and that of the input shaft of the transmission in succession to the speed stage changeover of the gear-mesh type transmission.
[0015] In a preferred mode for carrying out the invention, a plurality of control subperiods may be provided for the control unit in conjunction with coupling of the electromagnetic clutch, wherein a target slip speed change rate may be set for each of the plural control subperiods, for thereby effectuating feedback control of a command current value for the electromagnetic clutch.
[0016] In another preferred mode for carrying out the invention, condition for termination may be set for each of the plural control subperiods, wherein the control unit may preferably be so designed that every time the condition for termination is satisfied, the feedback control is caused to transit to a succeeding one of the plural control subperiods in a sequential manner.
[0017] In yet another mode for carrying out the invention, the control unit should preferably be so designed as to cause a first control subperiod to make transition to a second control subperiod when a predetermined time has lapsed in the first control subperiod immediately in succession to changeover of the speed stage of the gear-mesh type transmission, while when the slip rotation speed in the second control subperiod becomes smaller than a predetermined value inclusive, transition is made from the second control subperiod to a third control subperiod.
[0018] In still another mode for carrying out the invention, the control unit should preferably be so designed as to determine arithmetically a command current value for the electromagnetic clutch through an open loop control in a last control subperiod succeeding to the plural control subperiods.
[0019] In a further mode for carrying out the invention, the control unit should preferably be so designed that when condition for terminating the last control subperiod is satisfied, processing for completing the coupling operation of the electromagnetic clutch is executed.
[0020] In a yet further mode for carrying out the invention, the control unit should preferably be so designed that at a time point when an exciting current for the electromagnetic clutch has reached a target value, decision is made that the condition for terminating the last control subperiod is satisfied.
[0021] By virtue of the arrangements described above, there can be obtained a gear-mesh type automatic transmission system capable of controlling clutch coupling speed so as to mitigate shock which is otherwise likely to occur upon coupling of the clutch in succession to changeover of the speed stage regardless of the time-dependent deterioration of the electromagnetic clutch and the intrinsic performance dispersion among individual clutches.
[0022] The above and other objects, features and attendant advantages of the present invention will more easily be understood by reading the following description of the preferred embodiments thereof taken, only by way of example, in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In the course of the description which follows, reference is made to the drawings, in which:
[0024] [0024]FIG. 1 is a block diagram showing generally and schematically a structure of a gear-mesh type automatic transmission system according to a first embodiment of the present invention;
[0025] [0025]FIG. 2 is a timing chart for illustrating clutch coupling control operation in the gear-mesh type automatic transmission system according to the first embodiment of the invention shown in FIG. 1;
[0026] [0026]FIG. 3 is a flow chart for illustrating a decision processing for clutch coupling control in the gear-mesh type automatic transmission system according to the first embodiment of the invention; and
[0027] [0027]FIG. 4 is a flow chart for illustrating a clutch coupling control operation upon speed stage changeover from a first to a second speed stage in the gear-mesh type automatic transmission system according to the first embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The present invention will be described in detail in conjunction with what is presently considered as preferred or typical embodiments thereof by reference to the drawings. In the following description, like reference characters designate like or corresponding parts throughout the several views.
[0029] Embodiment 1
[0030] [0030]FIG. 1 is a block diagram showing generally and schematically a structure of the gear-mesh type automatic transmission system (which may also be termed as the gear-mesh type automatic speed change gear system) according to a first embodiment of the present invention. Referring to the figure, reference numeral 1 denotes an engine such as an internal combustion engine having an output shaft, i.e., a crank shaft 21 , on which an electromagnetic clutch 2 is mounted. A gear-mesh type speed change gear or transmission 3 is installed on an output shaft 22 of the electromagnetic clutch 2 . Parenthetically, the output shaft 22 of the electromagnetic clutch 2 constitutes an input shaft of the gear-mesh type transmission 3 . Accordingly, the shaft 22 may also be referred to as the input shaft of the gear-mesh type transmission 3 . The output torque of the gear-mesh type transmission 3 is operatively transmitted to tires (not shown) of a motor vehicle (not shown either) via an output shaft 23 of the transmission.
[0031] The engine 1 , the electromagnetic clutch 2 and the gear-mesh type transmission 3 are controlled by a control unit 4 which may be constituted by a microcomputer or microprocessor.
[0032] The gear-mesh type transmission 3 is provided with a shift/select actuator 5 and a shift/select position sensor 6 . The shift/select actuator 5 is designed to serve for gear change operation of the gear-mesh type transmission 3 , while the shift/select position sensor 6 is employed for detecting a shift/select position of the gear-mesh type transmission 3 .
[0033] An accelerator pedal (not shown) manipulated by an operator or a driver of the motor vehicle is provided with an accelerator pedal position sensor 7 for detecting a accelerator pedal depression stroke. Further provided is a shift lever 8 which is manipulated by the driver for outputting a signal indicative of the shift lever position.
[0034] A transmission output shaft rotation speed sensor 9 is provided in association with the output shaft of the gear-mesh type transmission 3 for detecting the rotation speed (rpm) of the output shaft 23 of the transmission 3 .
[0035] Output signals of the shift/select position sensor 6 , the accelerator pedal position sensor 7 , the shift lever 8 and the transmission output shaft rotation speed sensor 9 are inputted to (or fetched by) the control unit 4 .
[0036] Installed within an intake pipe 11 of the engine 1 is a throttle valve 12 the opening degree of which is controlled through a throttle valve actuator 10 .
[0037] The control unit 4 is so designed or programmed to control the gear-mesh type transmission 3 by controlling the shift/select actuator 5 while controlling the output torque of the engine 1 by controlling the throttle valve actuator 10 on the basis of the input signals delivered from the various sensors mentioned previously.
[0038] More specifically, the control unit 4 may be so designed or programmed as to process the output signal of the accelerator pedal position sensor 7 which indicates proportionally the accelerator pedal depression stroke, to thereby determine arithmetically the desired or target throttle valve opening degree which conforms to the accelerator pedal depression stroke to thereby drive the throttle valve actuator 10 so that the throttle valve can assume a position corresponding to a desired or target opening degree. In other words, the throttle valve 12 is controlled through a feedback control loop including the control unit 4 .
[0039] Supplied to the electromagnetic clutch 2 is a clutch exciting current of a magnitude which is proportional to the torque to be transmitted through the clutch (hereinafter also referred to as the clutch transmitting torque) under the control of the control unit 4 so that transmission/interruption (on/off) of the engine output torque from the crank shaft 21 to the input shaft 22 of the transmission 3 can controllably be realized.
[0040] Although it is presumed that the electromagnetic clutch 2 is employed in the case of the gear-mesh type automatic transmission system now under consideration, it goes without saying that a clutch of hydraulically driven type may equally be employed in place of the electromagnetic clutch 2 .
[0041] The gear-mesh type transmission 3 may include, for example, five sets of forward speed-change gears which mutually differ in respect to the gear ratio and one set of rearward speed-change gears, although they are omitted from illustration in the figure. The gear-mesh type transmission 3 undergoes speed change operations of the shift/select actuator 5 which is dedicated for the speed gear change operation under the control of the control unit 4 so that the desired or target speed stage can be put into effect. In other words, the gear-mesh type transmission 3 undergoes a feedback control so that the desired or target speed stage can be effectuated or validated.
[0042] Further, the control unit 4 is so designed or programmed as to fetch the signal indicating the accelerator pedal depression stroke, the position signal (switch signal) indicating the position of the shift lever 8 and the signal indicating the rotation speed (rpm) of the output shaft 23 of the transmission from the output of the accelerator pedal position sensor 7 , the shift lever position sensor and the transmission output shaft rotation speed sensor 9 , respectively, to thereby determine the speed stage suited for the running state of the motor vehicle in accordance with a relevant transmission shift pattern (not shown).
[0043] Additionally, the control unit 4 is designed or programmed to output a control signal for the shift/select actuator 5 while checking the shift/select position on the basis of the detection signal outputted from the shift/select position sensor 6 so that the speed change operation of the gear-mesh type transmission 3 can be performed for setting or validating the target speed stage.
[0044] Now, referring to a timing chart shown in FIG. 2, description will turn to the clutch coupling control operation in the gear-mesh type automatic transmission system according to the first embodiment of the invention shown in FIG. 1. Incidentally, the timing chart of FIG. 2 illustrates changes of the rotation speed (rpm) of the engine 1 (or the crank shaft 21 ), rotation speed (rpm) of the input shaft 22 of the transmission 3 , rate of change of the desired or target slip rotation speed (hereinafter also referred to as the target slip speed change rate) and the clutch current, respectively, as a function of time lapse.
[0045] More specifically, the timing chart shown in FIG. 2 is depicted in conjunction with the clutch control carried out after the speed stage changeover operation of the gear-mesh type transmission 3 . For convenience of the discussion, the clutch control period is assumed as being divided into four subperiods, i.e., subperiod A, subperiod B, subperiod C and subperiod D, wherein status transition is made from the subperiod A to the subperiod B, from the subperiod B to the subperiod C and from the subperiod C to the subperiod D in this order.
[0046] At first, in the subperiod A which starts from the time point at which the clutch coupling control operation begins, feedback control is so performed that the rate of change of a slip rotation speed (i.e., difference between the engine rotation speed and the input shaft rotation speed of the transmission, hereinafter also referred to as the slip speed change rate) remains at a low level. Thus, shock which would otherwise take place upon clutch coupling control operation can be mitigated.
[0047] Subsequently, in the subperiod B, a target slip speed change rate is set primarily in view of shortening the time taken for the speed change, because shock is difficult to occur even when the slip speed change rate is increased to a certain extent upon lapse of a certain time from the start of the clutch coupling control operation, whereon the feedback control is performed.
[0048] In succession, when the engine rotation speed approaches the rotation speed of the input shaft 22 of the gear-mesh type transmission 3 , a target slip speed change rate is set at a low level for intercoupling or combining together the engine rotation speed and the rotation speed of the input shaft of the gear-mesh type transmission 3 because shock is difficult to occur whereon the feedback control described previously is performed. This control is carried out during the subperiod C.
[0049] Finally, in the subperiod D, after coincidence has been detected between the engine rotation speed and the rotation speed of the input shaft 22 of the transmission 3 , the command value for the exciting current is increased at a constant rate through an open loop control toward a desired or target clutch excitation current value at which the engine output torque can sufficiently and satisfactorily be transmitted from the crank shaft 21 to the input shaft 22 of the transmission 3 .
[0050] In that case, the target clutch current ITGT in ampere or [A] for the feedback control can arithmetically be determined in accordance with the undermentioned expression (1):
ITGT= ( Ii ) n+KP·{ ( dNslp/dt ) o− ( dNslp/dt ) n}+KD·{ ( dNslp/dt )( n− 1)−( dNslp/dt ) n} (1)
[0051] where
[0052] (Ii)n in [A] represents an integral term of the target clutch current in the instant arithmetic operation,
[0053] KP in [A/(r/min/10 ms)] represents a proportional gain, (dNslp/dt)o in [r/min/10 ms] represents the target slip speed change rate,
[0054] (dNslp/dt)n in [r/min/10 ms] represents the slip speed change rate in the instant arithmetic operation,
[0055] KD in [A/(r/min/10 ms)] represents a differential gain, and
[0056] (dNslp/dt)(n− 1 ) in [r/min/10 ms] represents the target slip speed change rate in the preceding arithmetic operation.
[0057] In this conjunction, the target clutch current (Ii)n in [A] in the instant or current arithmetic operation can be determined in accordance with the following expression (2):
( Ii ) n= ( Ii )( n− 1)+ KI· {( dNslp/dt ) o− ( dNslp/dt ) n} (2)
[0058] where
[0059] (Ii)(n−1) in [A] represents the integral term of the target clutch current in the preceding arithmetic operation, and
[0060] KI in [A/(r/min/10 ms)] represents an integral gain.
[0061] Next, by reference to FIG. 3, description will turn to a basic decision processing procedure for the clutch coupling control operation in the gear-mesh type automatic transmission system according to the first embodiment of the invention. FIG. 3 is a flow chart for illustrating the decision processing for the clutch coupling control operation in the gear-mesh type automatic transmission system according to the first embodiment of the invention. The processing procedure or routine shown in FIG. 3 may be executed periodically at a predetermined time interval, e.g. every 10 ms.
[0062] Referring to FIG. 3, decision is made in a step S as to whether or not a clutch coupling request has been issued after the speed stage changeover or shift operation of the gear-mesh type transmission 3 . When it is decided that the clutch coupling request has not been issued (i.e., when the decision step S 1 results in negation “No”), the processing routine shown in FIG. 3 is terminated intactly.
[0063] On the other hand, when decision is made in the step S 1 to the effect that the clutch coupling request is issued (i.e., when the decision step S 1 results in affirmation “Yes”), then the processing routine proceeds to a step S 2 where it is decided whether or not the clutch coupling request now concerned is issued in conjunction with the speed stage changeover or shift from the first to the second speed stage.
[0064] When it is decided in the step S 2 that the clutch coupling request is issued in conjunction with the speed changeover or shift operation from the first to the second speed stage (i.e., when the decision step S 2 results in affirmation “Yes”), processing for the clutch coupling operation is executed in conjunction with the speed shift operation from the first to the second speed stage in a step S 3 , whereupon the processing routine shown in FIG. 3 comes to an end.
[0065] On the contrary, when the decision step S 2 results in negation “No”, indicating that the clutch coupling operation is not for the speed shift from the first to the second speed stage, then the clutch coupling processing for other speed shift operation is executed in a step S 4 . Needless to say, processing steps similar to those shown in FIG. 3 are executed for the clutch coupling operation relevant to the other speed change request.
[0066] Next, referring to FIG. 4, description will be made in concrete concerning the processing for the clutch coupling operation (FIG. 3, step S 3 ) performed in succession to the speed shift or changeover, for example, from the first to the second speed stage in the gear-mesh type automatic transmission system according to the first embodiment of the invention. By the way, FIG. 4 is a flow chart for illustrating a clutch coupling control operation succeeding to the speed changeover from the first to the second speed stage in the gear-mesh type automatic transmission system according to the instant embodiment of the invention.
[0067] Referring to FIG. 4, decision is first made in a step S 10 whether the control subperiod for the clutch coupling control for the speed shift from the first to the second speed stage falls in any one of the control subperiods A to D (see FIG. 2). When it is decided that the control subperiod is one of the subperiod A to subperiod C, then the target slip speed change rate is set for the relevant control subperiod (step S 11 , 21 or 31 ).
[0068] Further, when it is decided in the step S 10 that the control subperiod falls within the subperiod D, an increasing rate of the clutch current command value is set in a step S 41 .
[0069] Next, in succession to execution of the step S 11 , S 21 or the step S 31 in the subperiod A, the subperiod B or the subperiod C, the relevant current command value for exciting the electromagnetic clutch 2 is arithmetically determined in accordance with the expressions (1) and (2) for performing the feedback control described previously (step S 50 ).
[0070] On the other hand, after execution of the step S 41 for the subperiod D, the exciting current command value of the electromagnetic clutch 2 for the open loop control is arithmetically determined without executing the feedback control described hereinbefore (step S 51 ).
[0071] Subsequently, in succession to each step S 50 or S 51 described above, decision is made in a step S 12 , S 22 , S 32 or S 42 whether or not the condition of termination for the subperiod A, B, C or D is satisfied.
[0072] More specifically, in the step S 12 , decision is made as to the condition of termination for the subperiod A (e.g. lapse of 200 ms). When the decision results in that the subperiod-A terminating condition is satisfied (i.e., when the decision step S 12 results in affirmation “Yes”), then the control subperiod is updated to the subperiod B (step S 13 ), whereupon the processing routine shown in FIG. 4 comes to an end.
[0073] Further, in the step S 22 , decision is made as the condition of termination for the subperiod B, for example, as to whether or not the slip rotation speed (i.e., difference in rpm between the engine rotation speed and the input shaft rotation speed of the transmission, also referred to simply as the slip speed) is less than 300 rpm inclusive. When the decision results in that the subperiod-B terminating condition is satisfied (i.e., when the decision step S 22 results in affirmation “Yes”), then the control subperiod is updated to the subperiod C (step S 23 ), whereupon the processing routine shown in FIG. 4 comes to an end.
[0074] Further, in the step S 32 , decision is made as the condition of termination of the subperiod C, for example, as to whether or not the slip speed is less than 10 rpm inclusive. When the decision results in that the subperiod-C terminating condition is satisfied (i.e., when the decision step S 32 results in affirmation “Yes”), then the control subperiod is updated to the subperiod D (step S 33 ), whereupon the processing routine shown in FIG. 4 comes to an end.
[0075] Finally, in the step S 42 , decision is made as to the condition for termination of the subperiod D (e.g. as to whether the clutch exciting current has reached the target value). When the decision results in that the subperiod-D terminating condition is satisfied (i.e., when the decision step S 42 results in affirmation “Yes”), then a processing for completing the clutch coupling control operation is executed (step S 43 ), whereupon the processing routine shown in FIG. 4 comes to an end.
[0076] On the other hand, when decision is made in each step S 12 , S 22 , S 32 or S 42 such that the condition for termination of the relevant control subperiod is not satisfied (i.e., when the decision step S 12 , S 22 , S 32 or S 42 results in negation “No”), then the processing routine illustrated in FIG. 4 is immediately terminated.
[0077] As is apparent from the foregoing, by carrying out the coupling control of the electromagnetic clutch 2 after changeover of the speed stage of the gear-mesh type transmission 3 through feedback control of the rate of change of the slip speed, occurrence of shock due to deterioration or abrasion of the electromagnetic clutch 2 upon changeover or shift of the speed stage can satisfactorily be suppressed or prevented.
[0078] Further, the coupling control of the electromagnetic clutch 2 can be executed without paying attention to dispersion or variance in the degree of coupling force among the individual electromagnetic clutches 2 .
[0079] Many modifications and variations of the present invention are possible in the light of the above techniques. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
|
A gear-mesh type automatic transmission system capable of controlling clutch coupling speed so as to mitigate shock likely to occur upon changeover of speed stage regardless of not only time-dependent deterioration of an electromagnetic clutch but also dispersion among individual clutches. The gear-mesh type automatic transmission system includes an electromagnetic clutch ( 2 ) for effectuating transmission and interruption of output power from an output shaft ( 21 ) of an engine ( 1 ) to an input shaft ( 22 ) of a gear-mesh type transmission ( 3 ), a shift/select actuator ( 5 ) for shifting a speed change gear to a shift/select position in the gear-mesh type transmission ( 3 ), a shift/select position sensor ( 6 ) for detecting a shift/select position of the speed change gear, and a control unit ( 4 ) for driving the shift/select actuator ( 5 ) in accordance with a shift lever position selected by a driver, to thereby change over automatically the gear-mesh type transmission ( 3 ) to a target speed stage. The control unit ( 4 ) is designed to couple the electromagnetic clutch ( 2 ) while carrying out a feedback control on the basis of a rate of change of a slip rotation speed in succession to the speed stage changeover.
| 5
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the manufacture of uniform glass fiber mats by the wet-laid process, and more particularly, it is concerned with improved glass fiber dispersion compositions for use in such a process.
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 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; 3,021,255; 3,050,427; 3,103,461; 3,108,891; 3,228,825; 3,634,054; 3,749,638; 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 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.
For example, such polymeric suspending aids materials as polyacrylamides, hydroxyethyl cellulose and the like, provide a highly viscous aqueous solution at high material concentrations, which is difficult to handle, and particularly, which drains very slowly through the mat forming screen, or foraminous belt. Furthermore, the degree of the suspension formed using such materials is only fair, and suspensions having a fiber consistency of more than 0.005% give poor quality mats. The viscous suspensions also trap air upon agitation near the formation zone to form stable foams which adversely affect the uniformity and strength of the mats. Finally, the polymers are not effective at low concentrations, and so are expensive for use in what should be a low cost process.
A number of surfactant materials also have been tried for dispersing glass fibers in water, for example, the cationic nitrogen surfactants described in Ger. DT No. 2454354/Fr. Demande No. 2,250,719 (June, 1975). With these surfactants, the glass fiber filaments are drawn from an extruder nozzle, coated with the cationic surfactant, and moistened before chopping into short-length fibers. The chopped fibers then are compounded in another aqueous solution of a cationic surfactant. Accordingly, in this process, the cationic surfactants are applied in two stages to form an aqueous solution and provide acceptable mats at reasonable speeds of mat production. Furthermore, the quality of the dispersions using the materials of this patent application also is poor.
Therefore, it is apparent that for a glass fiber dispersion technique to be effective, it is necessary that the dispersions meet several rigid criteria simultaneously which can provide means for making the desired high quality glass fiber mats at a rapid rate of production in an economically acceptable process. Such criteria are listed below:
1. The dispersing surfactant should provide a uniform dispersion of glass fibers in water effectively at low surfactant concentrations.
2. The dispersions should be efficient at high glass fiber consistencies so that the mats may be formed without having to expend an unnecessarily large amount of energy to separate and handle large quantities of water.
3. The dispersion compositions preferably should not be accompanied by a substantial increase in the viscosity of the medium, which would necessitate extensive pumping equipment at the screen to separate the fibers from the water, and which would make drying of the wet mat difficult.
4. The dispersion compositions should be capable of producing glass fiber mats which have a uniform distribution of fibers characterized by a multidirectional array of fibers. The finished mat product should possess uniform high-strength properties, particularly good tensile strength.
5. The dispersions should be capable of use in the wet-laid process in conventional equipment, at high rates of mat production, without generation of unwanted foams, and without corroding the plant machinery.
6. The surfactant materials preferably should be readily available, at low cost, and be capable of use either by direct addition to the fibers in water, or by precoating the fibers with the surfactant before admixing with water to form the aqueous dispersion composition.
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 improved glass fiber dispersions for making uniform glass fiber mats by the wet-laid process. The well dispersed glass fiber compositions of this invention are prepared by mixing bundles of chopped glass fibers in water with a surfactant which is a polyethoxylated derivative of the reaction product of fatty acids and polyethylenepolyamines. The dispersions are formed at relatively high glass fiber consistencies and at low surfactant concentrations. The resultant dispersions then are used to make very high quality glass fiber mats at high rates of production.
DETAILED DESCRIPTION OF THE INVENTION
The dispersant of the invention is a polyethoxylated derivative of the amide condensation product of fatty acids and polyethylenepolyamines. The preferred dispersant is made by condensing one mole of a mixture of coco and tallow fatty acids with one mole of a mixture of diethylenetriamine and triethylenetetramine, and then ethoxylating the resultant mixed amides with ethylene oxide.
The condensation reaction preferably is run with one mole of a 60/40 molecular mixture of diethylenetriamine and diethylenetetraamine at about 190°-200° C. under pressure of 450 lbs per sq. in. for 5 hours. The ethoxylation reaction is carried out on the resultant mixed amides with about 10-50 moles of ethylene oxides, preferably about 13.5 moles, at a temperature of about 120°-130° C., for a period of about 10 hours, in the presence of an alkaline catalyst, suitably caustic.
The fatty acids may contain from C 8 -C 30 carbon atoms, preferably C 12 -C 18 . The final product is sold as "Antarox G-200" by the GAF Corporation, New York, N.Y.
The product contains many discrete molecular species of which the most prominent and functional structures are the following: ##STR1## wherein a through k are positive integers; a and e can be simultaneously or individually zero; b, f, g and j can be individually, simultaneously or in any combination, zero; b cannot be zero unless a is zero; f and g cannot be zero unless e is zero; 200≧a+b+2c+4d+e+f+g+2h+2i+j+2k≧10; and R is alkyl, C 8 -C 30 .
In a typical wet-laid process for making glass fiber mats, a stock suspension of bundles of the fibrous material of predetermined fiber consistency is prepared by vigorous agitation with the dispersant 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 may be dried, if necessary, then treated with a binder, and, finally, thoroughly dried to give a finished non-woven mat product.
In the process of the present invention for the production of glass fiber mats, the 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 3-20 microns in diameter, preferably about 15 microns. In one embodiment, the fibers are added to water containing the surfactant of the invention to form a well-dispersed composition. Suitably, the dispersant 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 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 dispersant, and, preferably, between 0.025 to 0.25%.
As a feature of the invention, the glass fibers may be dispersed in the 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 a tenth of the fiber consistency.
The dispersion compositions of the invention 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.
The dispersion compositions of the invention produce glass fiber mats which have a high density of fibers therein 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.
The following examples will more particularly illustrate the invention.
EXAMPLE 1
To 200 ml. of water containing 400 ppm of Antarox G-200 surfactant (100% active, 0.08 g.) was added 1 g. of chopped bundles of E-fiberglass (1" in length, 15 microns in diameter) with vigorous agitation (2500 rpm) for about 20 minutes. An excellent dispersion of the bundles into filaments of the glass fibers was obtained at a resulting fiber consistency of 0.5%. The dispersion thus-formed was made into a glass mat in a laboratory Williams apparatus, dried and cured with a binder. The finished mat product exhibited a uniform distribution and multidirectional array of fibers therein.
EXAMPLE 2
The process of mat formation was carried out as in Example 1 at a 20 ppm concentration of Antarox G-200 dispersant and at a fiber consistency of 0.07%, which was diluted to a formation consistency of 0.02% before mat formation, using E-glass fiber bundles, 1/2" in length, and 15 microns in diameter. The agitation was carried out in a Lightening mixer at medium speed for about 20 minutes. The dispersion was passed through a mat-forming screen to form an excellent glass mat which was dried and cured as before.
|
What is provided herein is a method of dispersing bundles of glass fibers for making uniform glass fiber mats by the wet-laid process. Well-dispersed glass fiber compositions are prepared herein by agitating chopped bundles of glass fibers in water with a small amount of a surfactant which is a polyethoxylated derivative of the amide condensation product of fatty acids and polyethylenepolyamines. The dispersions are formed at relatively high glass fiber consistencies, and at low surfactant concentrations.
| 3
|
BRIEF DESCRIPTION OF THE INVENTION
A water soluble linear aminoplast-ether copolymer containing aminoplast segments interlinked through ether segments. These linear aminoplast ethers are extremely desirable associate thickeners for use in water based coating compositions.
BACKGROUND TO THE INVENTION
Aminoplasts are defined herein and in the claims as an A-stage class of thermosetting resin based on the reaction of an amine with an aldehyde and the related acetals containing amines or amides. The most commercially used aldehyde is formaldehyde, and the most important amines are urea and melamine. They are used in molding, adhesives, laminating, textile finishes, permanent-press fabrics, wash-and-wear apparel fabrics, protective coatings, paper manufacture, leather treatment, binders for fabrics, foundry sands, graphite resistors, plaster-of-paris fortification, foam structures, and ion-exchange resins. A significant structural component of an aminoplast resin is the amino group to which is bonded at least one alkylol or alkylol ether or ester functional group. Those functional groups enter into condensation (heterolytic) reactions and provide the leaving groups for the reaction. The aminoplast typically provides at least two of such amino groups per molecule and one or two functional groups per amino group. The condensation reaction can generate a low to moderate molecular weight polymer (as would occur in making a B-stage resin), a highly crosslinked polymer (as would occur in making a thermoset C-stage resin) by homopolymerization or copolymerization, or it can generate a modification of the resin that either provides other type functionality or eliminates such functionality from the resin. For example, a starting monomer that contains the amino group with an associated methylol or methylol ether or ester group can be partially condensed and modified with a monomer that possesses, in addition, different functionality (such as ethylenic unsaturation) and such partial modification allows the aminoplast to be dimerized, oligomerized or polymerized by a homolytic reaction through such different functionality to form aminoplasts with a plethora of methylol and/or methylol ether and/or ester groups. This same result can be achieved by different route, by having the skeleton of the aminoplast possess other functional groups that can enter into heterolytic or homolytic reactions. For example, methacrylamide can be reacted with formaldehyde to form an aminoplast, and through the unsaturation, polymerization can be effected to create a linear polymer with pendant methylol or methylol ether or ester functional groups. Illustrative of such aminoplasts are the following: ##STR2## wherein R is hydrogen, alkyl containing 1 to about 4 carbon atoms, and acyl containing 1 to about 4 carbon atoms; R 0 is alkyl of from 1 to about 4 carbon atoms, aryl, cycloalkyl, and the like; R 1 is alkyl of from 1 to about 4 carbon atoms; and x is 0 or 1, and y is at least 2.
The RO-- functionality of such aminoplasts provide the leaving groups of the alkylol (e.g., methylol) or alkylol ether or ester (e.g., methylol ether or ester) functional groups. Alkylol (e.g., methylol), alkylol ether (e.g., methylol ether) or alkylol ester (e.g., methylol ester) groups can condense with them selves to form ROH volatile compounds or water. They can condense with complementary functional groups, such as compounds containing active hydrogen groups, e.g., primary and secondary amines, carboxylic acids, alcohols, phenols, mercaptans, carboxamides (including amides from urea, thiourea), and the like.
Most aminoplasts contain a minor amount of dimer and oligomer products. These products are formed in the making of the aminoplast and represent precondensation between aminoplast monomers. The dimer and oligomer products contain substantially more --OR functionality than the aminoplast monomer.
As noted above, aminoplasts are used to form thermoset resin structures. Because they contain at least two RO-- functional groups, they are used to react in systems that contain at least two complementary functional groups. Frequently, aminoplasts are added to resin formulations as one of many components. In such embodiments, there are no perceptible step-wise reactions between the aminoplast and any other component of the formulation. In such situations, it is not feasible to determine with any degree of accuracy as to which of the specific components of the formulation the aminoplast reacts.
The term "associative thickener" is art recognized to mean a nonionic hydrophobically modified water-soluble polymer capable of interacting in aqueous solution with itself and with other species such as latex particles. Typically they are made by polymerizing polyethylene oxide prepolymers with isocyanates. Mono-ols or diols with large aryl, alkyl, or aryl/alkyl groups are included to provide the hydrophobic modification. They are described in a number of patents. Hoy et al., U.S. Pat. No. 4,426,485, patented Jan. 17, 1984, broadly describes these materials as "a water-soluble, thermoplastic, organic polymer . . . having segments of bunched monovalent hydrophobic groups." This patent, in its "Description of the Prior Art," discusses a major segment of the prior art, and without endorsing the conclusions therein stated, reference is made to such description to offer a background to this invention.
The two Emmons et al. patents, U.S. Pat. No. 4,079,028 and U.S. Pat. No. 4,155,892, patented Mar. 14, 1978 and May 22, 1979, respectively, describe polyurethane associative thickeners that contain hydrophobic groups interconnected by hydrophilic polyether groups. The thickeners are nonionic.
There are a number of commercial associative thickeners based on the descriptions of the Hoy et al. and Emmons et al. patents.
Background on the use of thickeners in waterborne polymer systems, including those embraced in the characterization of this invention is set forth in the extensive literature on the subject, such as U.S. Pat. Nos. 4,426,485, 4,155,892, 4,079,028; 3,035,004; 2,795,564; 2,875,166 and 3,037,952, for example. The polymeric thickeners of this invention are also suitable as substitutes for the polymeric thickeners in the polymeric systems disclosed in U.S. Pat. Nos. 2,875,166 and 3,035,004 and in Canadian Pat. No. 623,617.
For the purposes of this invention and the discussion of the prior art, the skeletal unit of the aminoplast is the structure of the aminoplast minus the RO-- leaving groups bonded to alkylene of the alkylol or alkylol ether or ester of the aminoplast, regardless of whether any of the RO-- groups are removed from the aminoplast. That skeletal unit is referred to herein and in the claims as "Amp."
In the following description and in the claims hereof, the term "water dispersible," as such relates to aminoplast containing compositions and precursors to such compositions, that are water soluble or mechanically dispersible in water in a stable particulate form. A stable particulate form is one that retains its chemical characteristics after an extended period of time. It can be mechanically mixed in such particulate form in water, for an extended period of time at normal ambient conditions.
The term "linear," when used herein and in the claims to characterize a polymer, relates to a polymer that is devoid of crosslinking or branching that renders the polymer solid and cured. A "wholly linear" polymer is a polymer that is devoid of crosslinking and branching. A linear polymer may or may not be a wholly linear polymer.
The symbols and designations used herein are intended to be consistently applied, especially as used in formulations and equations, unless specifically stated otherwise.
THE INVENTION
This invention relates to aminoplast-ether copolymers formed by a process that does not rely on an urethane-forming polymerization reaction in order to generate the copolymer's backbone structure.
This invention relates to a novel linear aminoplast-ether copolymer of the formula: ##STR3## where the divalent R 01 contains a divalent alkyleneoxy containing moiety, Amp is the skeletal residue of an aminoplast, as stated above, R is defined above, p is a positive number that is equal to the free valence of Amp minus 2, RO is bonded to alkylene units of Amp, and a is a number greater than 1, preferably greater than 2. Amp includes any dimer and oligomer component of the aminoplast. In a much preferred embodiment of the invention, R 01 is derived from a water dispersible alkylene polyether, preferably a water soluble alkylene polyether, and the novel linear aminoplast copolymer of the invention is water dispersible, and preferably, water soluble.
In addition, the invention relates to a novel linear aminoplast-ether co-polymer that contains one or more pendant groups, preferably hydrophobic pendant groups. Such a copolymer contains a unit of the formula: ##STR4## wherein R 02 is a hydrophobic group, different from RO--, that is covalently bonded to Amp through a heteroatom and contains at least two carbon atoms, preferably at least two sequential carbon atoms,
p 2 is number that is equal to the free valence of Amp minus (2+q), and
q is a positive number. The copolymer preferably contains a ratio of q/a that is at least about 0.01.
In another embodiment of the invention, the novel linear aminoplast-ether copolymer possesses end groups characterized by a component of the units making up the copolymer, or a monofunctional group that effectively end-caps the copolymer, forming the end group. This yields a copolymer of the formula: ##STR5## wherein each R 00 is the same or different terminal group, such as hydrogen, --R 01 --H, Amp bonded --(OR) p1 , --Amp--(OR) p1 , or any other monofunctional organic groups, such as alkyl, cycloalkyl, aryl, alkaryl, aralkyl, alkyoxyalkyl, aroxyalkyl, cycloalkoxyalkyl, and the like, and p 1 is a positive number that is equal to the free valence of Amp minus 1. In addition, the invention encompasses a copolymer of the formula: ##STR6## where each R 001 is the same or different, and is R 00 or R 02 .
A preferred composition of the invention is the novel linear aminoplast-ether copolymer comprising units of the formula: ##STR7## wherein R 01 and R are described above, n has a value of at least 2, x is 0 or 1, s is (3+x)-2, and the average value of x in the copolymer is about 0 to about 0.05. Another preferred composition of the invention is a novel linear aminoplast-ether copolymer having the formula: ##STR8## where s+t equals (i) the free valence of the ##STR9## moiety and (ii) 4-x; and the average value of t/s+t is about 0.01 to about 0.5.
In a further preferred embodiment of the invention, the novel linear aminoplast-ether copolymer of the invention comprises a copolymer that possesses end groups as illustrated by the following structure: ##STR10## wherein each R 002 is the same or different terminal group, such as hydrogen, --R 01 --H, --(OR) p1 , --Amp 0 --(OR) p1 , or any other monofunctional organic groups, such as alkyl, cycloalkyl, aryl, alkaryl, aralkyl, alkyoxyalkyl, aroxyalkyl, cycloalkoxyalkyl, and the like, and p 1 is a positive number that is equal to the free valence of Amp 0 minus 1. Amp 0 is depicted in formula V. In a preferred embodiment of the invention, the novel linear aminoplast-ether copolymer of the invention comprises a copolymer that possesses end groups affecting the performance of the copolymer. Such embodiment is illustrated by the following structure: ##STR11## wherein each R 003 is the same or different terminal group, such as hydrogen, --R 01 --H, --(OR) p1 , --Amp 0 --(OR) p1 , --R 02 or any other monofunctional organic groups, such as alkyl, cycloalkyl, aryl, alkaryl, aralkyl, alkyoxyalkyl, aroxyalkyl, cycloalkoxyalkyl, and the like, and p 1 is a positive number that is equal to the free valence of Amp 0 minus 1. Amp 0 has the same meaning as Amp.
In the foregoing characterizations set forth in formulae I, Ia, II, IIa, III, IIIa, IV, and IVa, each --OR and --OR 02 group is directly bonded to Amp through a hydrocarbyl moiety bonded to nitrogen therein.
This invention also relates to aqueous systems that contain any one or more of the above defined compositions. The invention relates to a thickened water containing composition in which water is present in a major amount and one or more of the aminoplast-based compositions of formulae I, Ia, II and IIa in a minor amount. Particularly preferred are such thickened water containing systems wherein the aminoplast-based compositions are the aminoplast-based compositions of formulae III, IIIa, IV and IVa. Particularly preferred water-based systems are coating, adhesive, quenchant, flocculant, cosmetic, ink, textile printing, paste, personal care product, cosmetics, hydraulic fluid, and the like, compositions.
In addition, the invention relates to a water-based composition that contains a major amount of water, minor amount of an associative thickener of the formula: ##STR12## wherein R 03 is a monovalent hydrophobe as illustrated in the definition of R 02 , and v has an average value of about 2 to about 10,000, and an amount of a "dispersed polymer" that is greater than the amount of the associative thickener, which dispersed polymer provides the basic utility for the composition. In this sense, the dispersed polymer is typically solvent dispersible, i.e., it has the capacity of being dissolved by a solvent, and on drying the composition, i.e., removing water and solvent present, the dispersed polymer is curable to either a solid thermoset structure or a solid thermoplastic.
Another feature of the invention is the method for making the linear aminoplast-ether copolymer. The method comprises the copolymerization reaction of a polyfunctional aminoplast with an ether containing two active hydrogen terminal groups, in the presence of an acid catalyst, especially a Bronsted-Lowery acid provided in catalytically effective amounts. The reaction is continued until the desired molecular weight is achieved. The desired molecular weight of the copolymer is dependent on the intended use of the copolymer. The molecular weight of the copolymer may range from about 12,000 to about 300,000, preferably from about 20,000 to about 100,000, and most preferably from about 30,000 to about 80,000. The aminoplast is a polymerizable resin of the general formula: ##STR13## wherein z is a positive number having a value of at least 2. The ether containing two active hydrogen terminal groups comprises a wide variety of compositions. A preferred class of them is nonionic. Illustrative of a preferred class of such ethers are polyalkylene oxides of the formula:
H-- Alkylene Oxide --H VIII.
where "alkylene oxide" is a divalent moiety containing at least two alkylene oxide units in which
1. the alkylene oxide units form a linear chain and provide a terminal OH, or
2. the alkylene oxide are bonded to a starter molecule, such as a diamine, urea, carbamate, phenoxy, amide, bis-imide, and the like, and providing a terminal OH, and/or
3. in which alkylene oxide are bonded to a terminal group that possesses a moiety that provides the active hydrogen (--H in formula VIII).
Further illustrative of such a preferred class are the water dispersible polyether compounds of the formula:
H.sub.x1 X--(R.sub.04).sub.x4 (R.sub.05).sub.x5 (R.sub.06).sub.x6 (R.sub.07).sub.x7 (R.sub.08).sub.x8 --XH.sub.x2 IX.
wherein
X is an active hydrogen-attached functional moiety such as oxy (--O--), sulfidyl (--S--), amino ( >N-- ), carboxy (--COO--), carboxamido, silyl, phosphoryl, ureido, and the like;
R 04 and R 08 are alkyl of 2 to about 8 carbon atoms;
R 05 and R 07 are one or more alkylene oxide units, e.g., such as water dispersible ethylene oxide, propylene oxide, mixed ethylene oxide/1,2-propylene oxide, mixed ethylene oxide/1,3-propylene oxide, mixed ethylene oxide/1,2-butylene oxide, mixed ethylene oxide/1,4-butylene oxide, and the like;
R 06 is a divalent group such as alkyleneoxy, alkylenepolyamine, cycloalkylene polyamine, phenoxy, uriedo, carbamate, amide, and the like;
x1 and x2 are each equal to the free valence of X;
x3, x4, x5, x6 and x7 are each 0 or 1, and one or more of x4 and x6 is 1.
Specific illustrations of a limited class of polyethers encompassed by formula IX are the Carbowax® and Pluronic® polyether diols sold by Union Carbide Chemicals & Plastics, Inc. and BASF Wyandotte, respectively. There are a variety of functional fluids based on alkylene oxides that are sold by Union Carbide Chemicals & Plastics, Inc. and BASF Wyandotte that are encompassed by formula IX. The molecular weight of the polyether reagent may range from about 106 and lower, to about 35,000, and higher.
DETAILED DESCRIPTION OF THE INVENTION
The linear aminoplast-ether copolymers of formula I et seq. are made by the novel condensation reaction of a polyfunctional aminoplast with a difunctional polyether (alone or with another polyol, as characterized with respect to formulae XII and XIII) in the presence of an acid catalyst. In the prior art, as noted above, aminoplasts are condensed with polyfunctional compounds to produce thermosetting resins or thermoset products (i.e., C-stage resin). The reaction of this invention produces a linear copolymer. Thus, the copolymers of formulae I, II, III, IV, and V are either liquid or thermoplastic solids that are solvent soluble and water dispersible.
This invention converts aminoplast reagents to make associative thickener copolymers. Aminoplast reagents include, but are not restricted to, aldehyde reaction products of melamines, ureas, benzoguanamines, glycolurils, and the like, to produce the array of aminoplasts, including but not limited to those described in FIG. 1 above. While any of these can be used to make associative thickeners, the glycolurils, such as those of formula X ##STR14## where R and x are defined above, have shown appropriate hydrolytic stability, when reacted with the polyether compounds, such as those encompassed by formula IX, to meet commercial criteria for associative thickener containing coating compositions. However, the reaction products of such aminoplasts with, e.g., thiols and NH groups from amides and carbamates, encompassed by formula IX, are much more hydrolytically stable than aminoplast ether linkages. Reaction with more hindered hydroxyl groups aids in providing a more stable product. The use of such reactants allow for the production of most hydrolytically stable aminoplast-based copolymers.
Suitable polyethers include such diverse polyalkylene polyethers as those having the formula: ##STR15## where x10 has a value of from about 1 to about 400, R 12 are alkyl of 1 to about 4 carbon atoms or acyl of 1 to about 3 carbon atoms. The preferred polyethers are water soluble. The most preferred polyethers are the alkylene polyethers where the predominant alkylene groups are ethylene. The most desirable polyethers are polyethylene oxide diols that possess molecular weights from about 1,000 to about 20,000.
Illustrative of the desirable polyethylene oxide diols are those of the formula:
HO--(--CH.sub.2 CH.sub.2 O).sub.x11 CH.sub.2 CH.sub.2 OH XI.
wherein x11 has a value of about 20 to about 500, preferably from about 50 to about 350, and most preferably from about 100 to about 250.
A further desirable embodiment of the invention is the modification of the linear aminoplast-ether copolymers of the invention by including a minor mole proportion of the following unit structure in the repeating structure of the copolymer:
--Amp--R.sub.13 -- XII.
wherein R 13 is the residue of a diol possessing greater hydrophobicity than R 01 , thereby providing for a linear copolymer containing the structure ##STR16## wherein x29 has a value that is greater than x30. Preferably, x30/x29 is less than about 1, preferably less than about 0.33. Illustrative of such R 13 groups are ##STR17## wherein x31 has a value of about 8 to about 20, x32 has a value of about 8 to about 23, x33 and x34 have values of 0 to about 8. The linear copolymer of formula XIII may be modified to possess the terminal groups of formulae Ia, IIa, IIIa, and IVa, discussed above.
The invention encompasses the linear aminoplast-ether copolymers embraced by formulae I and XIII, that contain, as well, hydrophobe pendant groups. This is illustrated by the presence of significant hydrophobic groups extending from aminoplast component of the linear backbone of the aminoplast-ether copolymer. Such hydrophobe groups are typically bonded to the backbone through ether or ester groups, as illustrated in formula VI. The nature of the hydrophobe can enhance the performance of the resulting aminoplast-ether copolymer as an associative thickener. Aromatic groups, e.g., phenyl, biphenyl, anthracyl, and the like, present in the hydrophobes are better than hydrophobes based on wholly aliphatic containing groups, especially for high shear viscosity attributes when used in water, and especially so with respect to the use of the associative thickeners of the invention in latex paints. Suitable hydrophobe groups are derived from alcohols, thiols, carboxylic acids, carboxamides, and carbamates of the formula: ##STR18## wherein R 09 is hydrogen, alkyl of 8 to about 24 carbon atoms, alkenyl of 8 to about 24 carbon atoms and alkynyl of 8 to about 24 carbon atoms, R 10 is mono, di and tri(aryl), R 11 is aryl, mono, di and tri(alkaryl), mono, di and tri(alkcycloalkyl), alkenyl and alkynyl where the alkyl, alkenyl and alkynyl contain 1 to about 24 carbon atoms and the cycloalkyl contains about 4 to about 8 carbon atoms, R 12 is one or more alkylene oxide, Y is an active hydrogen containing group such as OH, SH, COOH, CONHR 08 , NR 09 COOH, x13, x14, x15 and x16 are 0 or 1, and two or more of x13, x14, x15 and x16 have the value of 1 at the same time. Illustrative of such hydrophobe groups are the following precursor compounds from which the hydrophobe is derived: ##STR19## where the derived hydrophobes are ##STR20## and in which R 14 is hydrogen or alkyl of 1 to about 12 carbon atoms, R 15 is aryl or alkyl of 8 to 24 carbon atoms, x17 has a value of 7 to 23, x18 has a value of 1 to about 20, x19 has a value of 0 to about 8, x20 is 0 or 1, x21 is 0 or 1, x22 has a value of 1 to about 20, x23 has a value of 1 to about 23, x24 has a value of 0 to about 120, x25 has a value of 1 to about 20, x26 has a value of about 8 to about 60, and x27 is 0 or 1, the sum of x19 and x20 is 1 to about 23, and the sum of x22 and x25 is 1 to about 20. Another class of such hydrophobes are based on partially saponified fatty acid glycerides such as partially saponified linseed oil, tall oil, cottonseed oil, castor oil, coconut oil, corn oil, oiticica oil, perilla oil, poppyseed oil, rapeseed oil, and the like. A further class of such hydrophobes are ethoxylates of such partially saponified fatty acid glycerides. Illustrative of such esters are ##STR21## where R 16 are the hydrocarbyl portion of the natural fatty acid component of the fatty acid glycerides. Their ethoxylates are illustrated as ##STR22## where x28 has a value of 1 to about 200, and R 16 are the natural fatty acid component of the natural oil.
The choice of hydrophobe is primarily dependent on the use ascribed for the associative thickener of the invention. For example, the copolymer without the hydrophobe provides wetting agent and viscosity control features in water and with water-based compositions. In the demanding area of water-based coatings, it is desirable to include a hydrophobe as a component of the aminoplast-ether copolymer of the invention. Any of the aforementioned hydrophobes will affect the viscosity of a latex paint giving rise to benefits to the paint. However, certain of the hydrophobes in combination with certain of the aminoplast-ether copolymers, provide associative thickeners that essentially satisfy the most demanding commercial standards. For example, the use of dodecylphenol ethoxylates as the hydrophobe achieves particularly desirable high shear viscosity characteristics, resistance to spatter and gloss retention in semi-gloss paints when compared to nonylphenol and octylphenol ethoxylates which have often been employed in making associative thickeners with urethane in the polymer backbone. It has also been observed that using tristyrylphenol ethoxylates improves the gloss of semi-gloss paints even further and provides better high shear resistance according to the ICI cone and plate viscometer reading in flat latex paints. Reacting Bisphenol A into the associative thickeners (to form the copolymer of formula XIII) reduces the syneresis common when using associative thickeners in concert with cellulosics.
This invention relates to the use of any aminoplast, including those specifically recited in FIG. 1 above, to make the copolymer of the invention. Of these aminoplasts, exceptionally performing associative thickeners are obtained from the reaction of glycolurils with alkylene oxide glycols to form copolymers in which there are incorporated hydrophobic pendant and/or terminal moieties.
The production of the aminoplast-ether copolymers of the invention are made by solvent or melt polymerization. The typical preparation of an aminoplast-, such as glycoluril-, based associative thickener involves dissolving the aminoplast (e.g., glycoluril), a polyether compounds within the scope of formula IX (such as a Carbowax® polyether sold by Union Carbide Chemical and Plastics, Inc., Danbury, Conn.), with or without the addition of a more hydrophobic polyol within the scope of formula XII, and an ethoxylated hydrophobe, in a stripping solvent, such as alkylated benzene (e.g., toluene or xylenes). Prior to the combination of these reagent, each may be dried by azeotropic distillation with toluene, xylenes, or a mixture of them, or by any other drying procedure. Total concentration of the reagents in the solvent may be maintained from about 10 to about 60 weight %. The temperature of the mixture may be brought to about 60-140° C., preferably to about 80-120° C. An acid catalyst, such as a sulfonic acid catalyst, is then added. The reaction mixture is placed under reduced pressure to bring about a steady distillation of the toluene/xylenes which azeotropes the alcohol byproduct that must be removed in order for the reaction to proceed. Fresh solvent is constantly added to maintain a constant level. The reaction is allowed to proceed until a given high viscosity is achieved as measured by Gardner bubble tubes or until viscosity increase ceases. Such viscosity increase indicates an increase in the molecular weight of the copolymer.
SPECIFIC ILLUSTRATION OF SOLVENT PROCESS
1. Polyether polyol, hydrophobe and azeotroping solvent (e.g., toluene) are added to an appropriately sized container that accommodates a heater, temperature reading device, a nitrogen inlet, and a Dean Stark water trap and condenser.
2. The mixture of step 1 is heated to reflux to dry the mixture by azeotropic distillation. When water removal ceases, the mixture is cooled to about 100° C., and the water trap is removed. A distillation column and receiving vessel are installed.
3. Glycoluril (e.g., Powderlink 1174) is added and allowed to dissolve.
4. The catalyst is added and vacuum is applied. The pressure is reduced to a level that causes a steady distillation of solvent at about 100° C. The solvent is continually replenished from a pressure equalizing add funnel.
5. As the reaction proceeds, samples are removed and cooled to room temperature, and the Gardner bubble viscosity is measured.
6. When the proper viscosity is reached, the heat is removed and the mixture is cooled in a water bath. When the temperature has been reduced to below 75° C., an amine neutralizing agent is added. When the temperature is reduced to below 65° C., the polymer solution is poured out onto trays to air dry.
7. The dried polymer is cut into strips and redissolved in water or water/cosolvent mixture.
Polymerization in the melt involves the admixture of the same reagents in the absence of a solvent with a heavy duty laboratory mixer (such as an Universal Sigma Blade Mixer, sold by Baker Perkins Guittard SA, Paris, France) at a temperature sufficient to generate leaving groups and remove the reaction condensation products. The ventilation of the reaction is necessary in order to shift the reaction to the right and prevent an equilibrium reaction from occurring that impedes the reaction before the desired degree of polymerization is achieved.
Catalysts useable for effecting the copolymerization reaction includes the standard Bronsted-Lowery acid catalysts typically used for the condensation of aminoplast resins. Such acid catalysts include mineral acids (e.g., HCl, H 2 SO 4 , H 3 PO 4 , and the like), aryl sulfonic and alkylated aryl sulfonic acids, such as benzene sulfonic acid, p-toluene sulfonic acid, 1-naphthalene sulfonic acid, 2-naphthalene sulfonic acid, naphthalene-1,5-disulfonic acid, naphthalene-2,7-disulfonic acid, 1,3,6-naphthalene trisulfonic acid, naphtholsulfonic acid, dinonylnaphthalene disulfonic acid, dodecylbenzene sulfonic acid, oxalic acid, maleic acid, hexamic acid, alkyl phosphate ester, phthalic acid, and copolymerized acrylic acid. Of these catalysts, the sulfonic acid catalysts are the most effective and efficient for making the copolymers of the invention and dodecylbenzene sulfonic acid is the most preferred sulfonic acid catalyst.
Glycolurils are marketed by Cytec Industries as Cymel 1170, 1171, 1175 and Powderlink 1174. The Cymel typically contain a relatively high dimer/oligomer content of up to about 20 weight percent. Powderlink 1174 is a purer form that is solely the methyl ether of the formula: ##STR23## with about 3-5 weight percent of a dimer-oligomer of the monomer form. The purer the monomeric form of the aminoplast, the better it is in forming the copolymers of the invention. In about 5-7 weight percent of Powderlink 1174, x is 0, and such monomer form is trifunctional. The dimer-oligomer forms provide greater amounts of methoxy per molecule. For example, the dimer contains 6 methoxy functional groups. Such tri- and hexa-functionality does not alter this invention. The glycoluril ether linkage is much more resistant to hydrolysis than other aminoplast ether bonds. The higher dimer-oligomer content of the less pure glycolurils is not as favored as the lower dimeroligomer content of Powderlink 1174. 1
The ratio of aminoplast resin to the difunctional polyether is not narrowly critical. Typically, either the aminoplast resin or the difunctional polyether may be used in molar excess or stoichiometrically equivalent amounts in making the linear copolymer of the invention. In characterizing stoichiometry of the aminoplast resin, the resin is treated as being difunctional since linearity, according to the invention, is achieved when the aminoplast resin functions as a difunctional monomer even though the resin has the capability of higher functionality, e.g., tri- and tetrafunctionality, as the case may be. Thus, more than one mole of a polyether diol to one mole of, e.g., a glycoluril such as Powderlink 1174, represents a stoichiometric excess of the polyether to the glycoluril. Using this characterization, one may use between 1-2 moles of one of these reagents to 1 mole of the other. Either the polyether or the aminoplast may be in excess. However, it is more typical to use a mole amount of one reagent of about 1-1.75 to 1 of the other reagent. Typically, one employs a molar excess of the aminoplast resin because one may incorporate more hydrophobicity into the copolymer this way. This is especially the case when the copolymer is dimeric to oligomeric (e.g., possessing less than about 15 repeating units). When making higher polymeric structures, one uses a greater proportion of the polyether reagent, up to a 1:1 mole ratio. In general, it is desirable to use a molar excess of aminoplast of about 1.001-1.5 moles to 1 mole of the difunctional polyether. The amount of monofunctional hydrophobe reagent, in the typical case, should not exceed about 2 moles, nor be less than about 0.001 mole, of the monofunctional hydrophobe per mole of reacted aminoplast resin in the copolymer of the invention. Usually, the amount of monofunctional hydrophobe ranges from about 1 mole to about 0.01 mole per mole of reacted aminoplast.
The use of aminoplast reagents leads to an unexpected degree of formulating latitude in polymer synthesis. By varying the ratios of polyether and hydrophobe components, it is possible to make a large number of associative thickener copolymers that impart ICI viscosity of 1.2 poise in flat paint at 4.5 lb. loading, but which give a range of 15,000 to 75,000 centipoise at low shear. This latitude permits the facile tailoring of associative thickeners for a wide variety of paint and nonpaint applications.
The associative thickeners of the invention are particularly suitable for use in waterborne coating compositions. Waterborne coatings may be defined as coatings that contain water as the major volatile component and utilize water to dilute the coating to application consistency. These coatings consist mainly of resinous binder, pigments, water, and organic solvent. The type of pigmentation and the method of incorporation of the pigment vary widely.
Waterborne coatings can be made by dispersing, emulsifying or emulsion polymerizing the resin binder by use of added surfactants. This technique leads to opaque liquids. Because some hard resins are difficult or impossible to disperse directly into water, the resin sometimes can be dissolved in a water-immiscible solvent, and the resulting solution dispersed by the use of added surfactants. In this case, the solvent aids subsequent film coalescence. Surface activity or water dispersability also can be introduced into resin molecules by chemical modification of the resin by introducing functional polar groups such as the carboxyl group.
Some very finely dispersed resins appear as clear or slightly hazy liquids; they frequently are described as soluble, solubilized, colloidal dispersions, micro-emulsions, hydrosols, etc. These resins contain built-in functional groups that confer water "solubility" upon the resin, and, normally, external added surfactants are not used.
Waterborne resin binders can be classified as anionic, cationic, or non-ionic. Anionic dispersions are characterized by negative charges on the resin or by negative charges on the surfactant associated with the resin. Cationic dispersions have a positive charge on the resin or on the surfactant associated with the resin. Nonionic dispersions are those that have been dispersed by addition of nonionic surfactants or that contain a built-in hydrophilic segment such as polyethylene oxide which is part of the main chain of a relatively hydrophobic resin molecule.
The coating compositions may be of the thermosetting or thermoplastic varieties. The resin used in forming the coating may be insoluble in water, and the conversion of such a resin into a waterborne system typically involves converting the resin into an emulsion or dispersion. In the context of this invention, the waterborne composition contains the aminoplast-ether copolymer associative thickener of the invention.
The aqueous polymer dispersions may be prepared according to well known emulsion polymerization procedures, using one or more emulsifiers of an anionic, cationic, or nonionic type. Mixtures of two or more nonneutralizing emulsifiers regardless of type may be used. The amount of emulsifier may range from about 0.1 to 10% by weight or sometimes even more, based on the weight of the total monomer charge. In general, the molecular weight of these emulsion polymers is high, e.g., from about 100,000 to 10,000,000 number average molecular weight, most commonly above 500,000.
The water insoluble resin may be any of those known in the art, and may be a conventional natural or synthetic polymer latex emulsified with one of a nonionic, cationic or anionic surfactant. The primary resins are based on homopolymerized and copolymerized olefinic monomers such as vinyl acetate; vinyl chloride; styrene; butadiene; vinylidene chloride; acrylonitrile; methacrylonitrile; acrylic acid; methacrylic acid; alkyl acrylates; alkyl methacrylates; acrylamide; methacrylamide; hydroxyethyl methacrylate ("HEMA"); glycidyl methacrylate; dihydroxypropyl methacrylate; homopolymers of C 2 -C 40 alpha-olefins such as ethylene, isobutylene, octene, nonene, and styrene, and the like; copolymers of one or more of these hydrocarbons with one or more esters, nitriles or amides of acrylic acid or of methacrylic acid or with vinyl esters, such as vinyl acetate and vinyl chloride, or with vinylidene chloride; and diene polymers, such as copolymers of butadiene with one or more of styrene, vinyl toluene, acrylonitrile, methacrylonitrile, and esters of acrylic acid or methacrylic acid, and the like. It is also quite common to include a small amount, such as 0.1 to 5% or more, of an acid monomer in the monomer mixture used for making the copolymers mentioned above by emulsion polymerization. Acids used include acrylic, methacrylic, itaconic, crotonic, maleic, fumaric, and the like.
The vinyl acetate copolymers are well-known and include copolymers such as vinyl acetate/butyl acrylate/2-ethylhexyl acrylate, vinyl acetate/butyl maleate, vinyl acetate/ethylene, vinyl acetate/vinyl chloride/butyl acrylate and vinyl acetate/vinyl chloride/ethylene.
Other waterborne systems involve reactive copolymers that are crosslinked by the presence of complementary functional groups in the system. For example, a copolymer of acrylic ester/glycidylmethacrylate can be emulsified and crosslinked by the presence of a melamine-formaldehyde resin similarly emulsified in the system. In another system, a copolymer of HEMA and another acrylate, hydroxyl terminated polyesters, polyethers, or polyurethanes, can be emulsified and crosslinked by the presence of either an aminoplast resin, a polyisocyanate or blocked polyisocyanate.
The term "acrylic polymer" means any polymer wherein at least 50% by weight is an acrylic or methacrylic acid or ester, including mixtures of such acids and esters individually and together. The term "vinyl acetate polymer" means any polymer containing at least 50% by weight of vinyl acetate.
Even small particle size (about 0.1-0.15 micron) acrylic and other latices are thickened effectively, and flow and leveling improved, by thickeners of the invention.
EXAMPLE 1
Carbowax® 8000 2 (300 grams, 0.0357 moles), Igepal RC-620 3 (23.0 grams, 0.0338 moles), a mixture of dodecylphenolethoxylates, were combined with 1356 grams toluene in a 2 liter reaction vessel fitted with a Dean Stark water trap. The mixture was refluxed under nitrogen to remove water by azeotropic distillation. The Dean Stark trap was removed, and a distillation column was fitted to the flask. Powderlink 1174 (15.92 grams, 0.050 moles) was added and the temperature was raised to 100° C. and Nacure 5076 4 (1.38 grams) (dodecylbenzene sulfonic acid) was added. Vacuum was applied to reduce the pressure inside the vessel to approximately 510 mm Hg. At this pressure the toluene distilled at a slow, steady rate. The toluene was constantly replenished to maintain a constant solvent level. This proceeded for 125 minutes at which time the viscosity was "X" on the Gardner bubble scale. The copolymer solution was cooled to 70° C. and dimethylethanolamine (0.53 gram) was added to quench the acid. The copolymer solution was cooled further to 60° C. and then poured out onto trays to air dry. The dried polymer was cut into small pieces and was dissolved at 20% polymer solids in a 4/1 water-diethylene glycol monobutyl ether mixture.
EXAMPLE 2
Procedure For Making Associative Thickeners Without Solvent
Carbowax 8000 (2204 grams, 0.262 moles) Igepal RC620 (168.9 grams, 0.248 moles), and 500 grams of toluene were placed in a 12 liter vessel equipped with a Dean Stark water trap. The materials were heated to reflux to azeotrope off water. Once the mixture was dry the remainder of the toluene was removed with vacuum. Powderlink 1174 (117.0 grams, 0.367 moles) was added and allowed to melt out. After the Powderlink had melted the material in the vessel was transferred to a a liter sigma blade mixer pre-heated to 105° C. The mixer was turned to run at 20 rpm. Nacure 5076 catalyst (7.10 grams) was added and the top was placed on the mixer. Vacuum was applied (27/30 in. achieved) and held for 1.75 hours as the viscosity increased. When the material had become quite viscous the heat was removed and dimethylethanolamine (3.87 grams, 0.043 mole) in 10 grams of toluene was added and the mixture was allowed to stir for a further 30 minutes. Diethyleneglycol monobutyl ether (1850 grams) and deionized water (7200 grams) were added and the mixture was allowed to stir until the material had dissolved. The resulting solution was filtered through a cone filter. Paint results are as follows:
______________________________________flat vinyl acrylic semi-gloss vinyl acrylic:(formulation below): (formulation below):______________________________________ICI:1.05 poise ICI:0.90 poiseStormer: 104 KU Stormer: 78 KUBrookfield: 49,000 cps Brookfield: 8,000 cps______________________________________
EXAMPLE 3
Using the procedure of Example 1, with the indicated modifications, the following other aminoplast-ether copolymers were made:
______________________________________Aminoplast-ether copolymer formulatlonReagent Concentration______________________________________Cymel 1171 (mixed ether glycoluril).sup.5 0.0628 molesCarbowax 8000 0.0349 molesTergitol NP-10.sup.6 0.0489 molesp-Toluene sulfonic acid 0.53 gramstoluene 1412 grams______________________________________ .sup.5 Cytec Industries, Inc. .sup.6 Ethoxylated nonyl phenol, sold by Union Carbide Chemical & Plastics, Inc.
Conditions: The maximum reaction temperature was 100° C. The reaction was carried out at atmospheric pressure (no vacuum pulled). The Gardner scale was used in monitoring viscosity.
______________________________________Reagent Concentration______________________________________Cymel 303 (hexamethoxymethylmelamine).sup.7 0.070 molesCarbowax 8000 0.047 molesTergitol NP-10 0.052 molesp-Toluene sulfonic acid 0.94 gramstoluene 1,665 grams______________________________________
Conditions: The maximum reaction temperature was 100° C. The reaction was carried out at atmospheric pressure (no vacuum pulled). The Gardner scale was used in monitoring viscosity.
Evaluation in Semi-Gloss Latex Paint Formulation
The 20% solution of example 1 was evaluated in a semi-gloss trade paint formulation, which consisted of a 24.4% PVC system using UCAR 376 vinyl-acrylic latex with Ti-Pure R-900 TiO 2 . Listed below are the rheological and application results for example 1 and two commercial nonionic associative thickeners.
______________________________________ Loading, Brook- active fieldAssociative lbs/100 cps @ Stormer ICI 60°Thickeners gallons 0.5 rpm KU poise Sag gloss______________________________________Example 1 5.0 9,720 85 1.00 10.0 45Acrysol SCT-270.sup.8 5.0 13,200 95 1.22 13.6 59Acrysol RM-825.sup.9 5.0 2,640 85 1.14 6.8 37______________________________________ .sup.7 Cytec Industries, Inc. .sup.8 Rohm & Haas Company, Philadelphia, PA .sup.9 Rohm & Haas Company, Philadelphia, PA
______________________________________Evaluation In Flat Latex Paint Formulation Loading, activeAssociative lbs/100 Brookfield Stormer ICI SpatterThickeners gallons cps @ 0.5 rpm KU poise amount______________________________________Example 1 4.5 36,240 106 1.22 traceAcrysol SCT-270 4.5 59,600 118 1.40 nilAcrysol RM-825 4.5 10,000 95 1.25 trace______________________________________
Procedure For Making and Testing Latex Paint Using Aminoplast Based Associative Thickeners
The following are the two primary formulations for evaluating aminoplast based associative thickeners. One is of a flat vinyl acrylic and the other is a semi-gloss vinyl acrylic. Typically both formulations are made in 5 gallon batches that are split into pints after the grind and let-down stage, but prior to the addition of the premix which contains the associative thickener.
The premix is added while the paint is being well agitated to ensure that the associative thickener is well incorporated into the paint. The paint is then allowed to sit at rest for 60 minutes to allow the material to further equilibrate followed by rheological measurements which involve
1. viscosity measurement in Krebs Units (KU) on a Stormer viscometer (ASTM D 562-81)
2. high shear measurement in poise at 10,000 s -1 on an ICI cone and plate viscometer (ASTM D 4287-83)
3. pH and temperature measurements are obtained.
The paints are maintained at room temperature (˜23.5° C.) and are evaluated as above at 24 hours, 1 week, 1, 2, 3, 6, and 12 months with the following additions:
1. a syneresis measurement is obtained by determining the amount in millimeters of the clear liquid that may separate to the top of the paint
2. a low shear measurement is obtained in centipoise (cps) at 0.5 rpm on a Brookfield RVT viscometer (ASTM D 2196-86).
After the 24 hour rheological measurements the flat paints are evaluated for spatter resistance according to ASTM procedure D 4707-87 with the exception that the paints are rated by the amount of spatter produced from nil, trace, slight, definite and pronounced. After the 24 hour Theological measurements the semi-gloss paints are evaluated for gloss at 60° C. after 1 day and 1 week room temperature air dry of a 0.004 mil draw down. Also the semi-gloss paints are evaluated for sag and leveling according to ASTM procedures D 4400-84 and D 2801-69.
The hydrolytic stability of the associative thickeners are determined by subjecting the paints to an elevated temperature (48.9° C.) for 4 weeks with rheological measurements obtained at 1 week intervals. The associative thickeners are determined to be stable if the Stormer viscosity does not lose more than 10% of the initial value.
Procedure For Making Latex Paint
1. Add water (and propylene glycol for semi-gloss) to 5-gallon container, begin agitation on a Hockmeyer Model Lab 2 type disperser equipped with a 4 inch dispersing blade.
2. Add HEC for the flat formulation and let mix agitate 5 minutes at low speed (˜1000 rpm).
3. Add dispersant and mix 5 minutes, add other additives and pigment(s) and grind at high speed (˜2000 rpm) for the specified time.
4. For the semi-gloss formulation prepare a premix in a separate container consisting of the water, HEC and ammonia, ensuring that the HEC is well dispersed in the water prior to the addition of the ammonia.
5. Add remaining let-down ingredients and agitate for 40 minutes, check weight per gallon and pH, divide into pint containers.
______________________________________Flat vinyl acrylicGrind Stage Supplier Pounds Gallons______________________________________Water 170.94 20.52Cellosize ER-15K Union Carbide 1.00 0.09(HEC thickener) Mix HEC 5 minutes at low speed.Tamol 731 (dispersant) Rohm & Haas 10.50 1.14Proxel GXL (preserva- Zeneca Biocides 1.00 0.10tive)Colloids 643 Rhone-Poulenc 2.00 0.26(defoamer)AMP-95 (Co- Angus Chemical 1.00 0.13dispersant)Tergitol NP-10 Rohm & Haas 1.00 0.11(Nonionic surfactant)TI-Pure R-901 (TiO.sub.2 DuPont 200.00 6.40Primary HidingPigment) Grind TiO.sub.2 @ high speed 20 minutesASP-400 (Aluminum Minerals & Chemicals 125.0 5.82Silicate extenderpigment)Duramite CaCO.sub.3 Thompson, Weinman & Co. 201.2 8.91(extender pigment) Grind @ high speed 20 minutes Record maximum grind temperatureLet DownWater 50.00 6.00UCAR 376 (Vinyl- Union Carbide 271.5 30.00acrylic latex 55%solids)Texanol (Coalescing Eastman Chemical 7.90 1.00Agent)Ammonia (pH ad- Aldrich 1.00 0.12justing agent) Sub total: 1044.04 Mix at low speed 30 minutes Weight/Gallon 12.95 Record pH: Remove and divide into pints (522 grams/pint)Premix:Propylene glycol Chemcentral 18.60 2.15(freeze thaw agent)Water 117.70 14.13Associative thickener Example 1 above 22.50 2.60at 20% solidsColloids 643 Rhone-Poulenc 4.00 0.52(defoamer) Total: 1206.84 100.00 Pigment volume concentration % 55.34 Volume Solids % 38.19______________________________________
______________________________________Semi-gloss vinyl acrylicGrind Stage Supplier Pounds Gallons______________________________________Water 9.58 1.15Propylene glycol Chemocentral 60.00 6.94Tamol 731 (dispersant) Rohm & Haas 10.20 1.11Colloids 643 (defoamer) Rhone Poulenc 1.25 0.16Ti-Pure R-900 (TiO.sub.2 DuPont 255.00 7.66Hiding Pigment) Grind TiO.sub.2 @ high speed 30 minutes; record maximum grind temperature:Let DownWater 130.00 15.61Cellocize ER-15,000 (HEC 1.00 0.09thickener) Premix water and HEC, add ammonia, agitate 10 minutesUCAR 376 (Vinyl-acrylic latex Union Carbide 417.00 46.0855% solids)Ammonia 2.00 0.24Texanol (Coalescing Agent) Eastman Chemical 11.50 1.45Triton GR-7M (Anionic Rohm & Haas 1.00 0.12surfactant)Colloids 643 (defoamer) Rhone Poulenc 1.25 0.16Nuosept 95 (biocide) Huls America 3.00 0.33 Sub Total 902.78 Mix at low speed 30 minutesPremix:Water 129.80 15.58Triton x 114 (nonionic Rohm & Haas 1.00 0.11surfactant)Associative Thickener at Example 1 above 25.00 2.8920% solidsColoids 643 (defoamer) Rhone Poulenc 2.50 0.33 Total: 1061.08 100.00 Pigment volume concentration %: 23.19 Volume solids %: 33.03______________________________________
|
A linear aminoplast-ether copolymer of the formula: ##STR1## where the divalent R 01 contains a divalent alkyleneoxy containing moiety, Amp is the skeletal residue of an aminoplast, R is hydrogen, alkyl containing 1 to about 4 carbon atoms, and acyl containing 1 to about 4 carbon atoms, p is a positive number that is equal to the free valence of Amp minus 2, RO is bonded to alkylene units of Amp, and a is a number greater than 1. The method for making the copolymer is described.
| 2
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and amplifier for cancelling magnetic coupling, and more particularly, to a method and amplifier capable of reducing in-phase/quadrature-phase (IQ) phase imbalance and gain imbalance, and minimizing layout area.
2. Description of the Prior Art
In communication systems, a carrier is frequently utilized for carrying baseband signals that contain data. Generally, a carrier is a high frequency signal. However, due to bandwidth limitation, a transmitter adopts a modulation scheme with high bandwidth efficiency. A quadrature amplitude modulation (QAM) is one of frequently utilized modulation schemes.
Generally, in a QAM system, signals are processed in two different paths. Ideally, the incoming signals are multiplied by an in-phase carrier (in-phase carrier) g sin wt and a quadrature-phase carrier g cos wt two mixers for modulation in the two paths, respectively, wherein g is the gain, and w is the angular frequency. In practice, factors such as magnetic coupling between inductors, temperature, process and supply voltage offset may result in gain imbalance and phase imbalance between the in-phase carrier g sin wt and the quadrature-phase carrier g cos wt, i.e. in-phase/quadrature-phase (IQ) imbalance. In other words, the oscillating signals utilized by the mixers may become (g+α)sin wt and g cos(wt+θ), where α is the gain imbalance and θ is the phase imbalance. In such a condition, there will be gain imbalance and phase imbalance between the mixed in-phase signal and the mixed quadrature-phase signal.
For example, please refer to FIG. 1A , which is a schematic diagram of a conventional quadrature amplifier 100 . For clearly illustrating, the quadrature amplifier 100 shown in FIG. 1A only includes differential amplifiers 102 , 104 and inductors 106 , 108 , while other components of the quadrature amplifier 100 are not shown. The inductors 106 , 108 form inductors of two inductor capacitor (LC) tanks, respectively. The amplifier 102 and the inductor 106 are in an in-phase path (I path), and the amplifier 104 and the inductor 108 are in a quadrature-phase path (Q path), wherein a distance between the inductors 106 and 108 is H. In the quadrature amplifier 100 , terminals IN and IP in the in-phase path output an in-phase negative signal S 1 and an in-phase positive signal S 2 , respectively, and terminals QN and QP in the quadrature-phase path output a quadrature-phase negative signal S 3 and a quadrature-phase positive signal S 4 , respectively. Ideally, a phase difference between the in-phase positive signal S 2 and the quadrature-phase positive signal S 4 is 90 degree. However, in order to keep carrier frequency within a range, inductors are utilized to achieve band-pass effect, and magnetic coupling between inductors may induce magnetic fields and generate corresponding induced currents, causing IQ imbalance.
For example, as shown in FIG. 1B to FIG. 1D , which are schematic diagrams of IQ phase imbalance between the in-phase positive signal S 2 and the quadrature-phase positive signal S 4 when the inductors 106 and 108 shown in FIG. 1A have different coil winding directions. In FIG. 1B , coil winding directions of the inductors 106 and 108 are clockwise, and thus magnetic field directions are downwards through paper. In such a situation, magnetic coupling between inductors having magnetic fields with a same direction generates induced currents, which shifts the in-phase positive signal S 2 and the quadrature-phase positive signal S 4 from original solid lines to dotted lines. Take a point A shown in FIG. 1B as an example, ideally, a phase of the in-phase positive signal S 2 is 0 degree and a phase of the quadrature-phase positive signal S 4 is 90 degree, such that a phase difference in between is 90 degree. However, after being affected by the induced currents generated by magnetic coupling between inductors having magnetic fields with the same direction, the phase of the in-phase positive signal S 2 is greater than 0 degree and the phase of the quadrature-phase positive signal S 4 is less than 90 degree, such that the phase difference in between is less than 90 degree, causing IQ phase imbalance.
Similarly, in FIG. 1D , coil winding directions of the inductors 106 and 108 are counterclockwise, and thus magnetic field directions are upwards through paper. Magnetic coupling between inductors having magnetic fields with a same direction generates induced currents, which results a phase difference between the in-phase positive signal S 2 and the quadrature-phase positive signal S 4 less than 90 degree, causing IQ phase imbalance. Similarly, in FIG. 1C , coil winding directions of the inductors 106 and 108 are clockwise and counterclockwise, respectively, and thus magnetic field directions are downwards through paper and upwards through paper, respectively. Take a point C shown in FIG. 1C as an example, after being affected by induced currents generated by magnetic coupling between inductors having magnetic fields with opposite directions, a phase of the in-phase positive signal S 2 less than 0 degree and a phase of the quadrature-phase positive signal S 4 is greater than 90 degree, such that a phase difference in between is greater than 90 degree, causing IQ phase imbalance.
In the prior art, in order to reduce IQ imbalance caused by magnetic coupling between inductors, the distance H between the inductors 106 and 108 is required to be very long, so as to reduce induced currents. As a result, large layout area is required, and magnetic coupling effect can not be totally eliminated, wherein the issue of IQ imbalance can not be effectively solved. Thus, there is a need for improvement of the prior art.
SUMMARY OF THE INVENTION
It is therefore an objective of the present invention to provide a method and amplifier for cancelling magnetic coupling.
The present invention discloses a method for cancelling magnetic coupling in an amplifier. The amplifier includes a first path and a second path for outputting a first signal and a second signal, respectively. The second signal and the first signal have a specific phase difference. The method includes steps of forming a first inductor capacitor (LC) tank and a second LC tank in the first path; and forming a third LC tank and a fourth LC tank in the second path.
The present invention further discloses an amplifier capable of cancelling internal magnetic coupling between inductors on different paths. The amplifier includes a first path, for outputting a first signal, comprising a first inductor capacitor (LC) tank and a second LC tank; and a second path, for outputting a second signal, comprising a third LC tank and a fourth LC tank, the second signal and the first signal having a specific phase difference.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic diagram of a conventional quadrature amplifier.
FIG. 1B to FIG. 1D are schematic diagrams of IQ phase imbalance between an in-phase positive signal and a quadrature-phase positive signal when the inductors shown in FIG. 1A have different coil winding directions.
FIG. 2A is a schematic diagram of an amplifier according to an embodiment of the present invention.
FIG. 2B is a schematic diagram of magnetic coupling between inductors shown in FIG. 2A .
FIG. 3A and FIG. 3B are schematic diagrams of inductors shown in FIG. 2A having different coil winding directions.
FIG. 4A is a schematic diagram of IQ imbalance magnitude of the quadrature amplifier shown in FIG. 1A .
FIG. 4B is a schematic diagram of IQ imbalance magnitude of the amplifier shown in FIG. 2A .
FIG. 5A is a schematic diagram of an amplifier according to another embodiment of the present invention.
FIG. 5B is a schematic diagram of magnetic coupling between inductors shown in FIG. 5A .
FIG. 6A and FIG. 6B are schematic diagrams of inductors shown in FIG. 5A having different coil winding directions.
FIG. 7 is a schematic diagram of a process according to an embodiment of the present invention.
DETAILED DESCRIPTION
Please refer to FIG. 2A , which is a schematic diagram of an amplifier 200 according to an embodiment of the present invention. For simplicity, the amplifier 200 shown in FIG. 2A only includes an in-phase path (I path), for outputting an in-phase negative signal S 1 ′ and an in-phase positive signal S 2 ′ at a terminal IN and a terminal IP, respectively, and a quadrature-phase path, for outputting a quadrature-phase negative signal S 3 ′ and a quadrature-phase positive signal S 4 ′ at a terminal QN and a terminal QP, respectively. In detail, the in-phase path includes differential amplifiers 202 , 204 and inductors 206 , 208 . The quadrature-phase path includes differential amplifiers 210 , 212 and inductors 214 , 216 . The inductors 206 , 208 , 214 , 216 form inductors of inductor capacitor (LC) tanks, respectively. The in-phase path and the quadrature-phase path are cross, i.e. the differential amplifiers 202 , 212 and the inductors 206 , 216 are in parallel with the differential amplifiers 210 , 204 and the inductors 214 , 208 . Noticeably, the amplifier 200 can further include components such as feedback circuit, which is not limited to this, and amplifiers 202 , 204 , 210 , 212 are not limited to differential amplifiers.
By increasing an amount of LC tanks and adjusting relative positions and coil winding directions, i.e. magnetic field directions, of the inductors 206 , 208 , 214 and 216 in the amplifier 200 , the magnetic coupling between inductors can effective cancelled, so as to reduce IQ imbalance. Thus, a phase difference between the in-phase positive signal S 2 ′ and the quadrature-phase positive signal S 4 ′ is substantially 90 degree, and layout area is minimized. Please refer to FIG. 2B , which is a schematic diagram of the magnetic coupling between the inductors 206 , 208 , 214 and 216 shown in FIG. 2A . K 1 is a magnetic coupling coefficient between the inductors 206 and 214 or the inductors 208 and 216 , K 2 is a magnetic coupling coefficient between the inductors 206 and 216 or the inductors 214 and 208 , and K 3 is a magnetic coupling coefficient between the inductors 206 and 208 or the inductors 214 and 216 . Since IQ imbalance between signals with a same phase is small, an effect the magnetic coupling coefficient K 3 can be ignored. Therefore, as long as relative distances and the coil winding directions of the inductors 206 , 208 , 214 and 216 are properly adjusted, induced currents generated by magnetic coupling can be cancelled with each other, so as to reduce IQ imbalance and minimize layout area. For example, by properly adjusting the relative distances and the coil winding directions of the inductors 206 , 214 and 216 , magnetic coupling the inductor 206 by the magnetic coupling coefficients K 1 and K 2 has a same magnitude with opposite directions, i.e. induced currents can be cancelled with each other, so as to reduce IQ imbalance, and minimize layout area.
In detail, please refer to FIG. 3A and FIG. 3B , which are schematic diagrams of the inductors 206 , 208 , 214 and 216 shown in FIG. 2A having different coil winding directions. In FIG. 3A , coil winding directions of the inductors 206 and 214 are clockwise, and thus magnetic field directions thereof are downwards through paper, while coil winding directions of the inductor 208 and 216 are counterclockwise, and thus magnetic field directions thereof are upwards through paper. In such a condition, since IQ imbalance between signals with a same phase is small, the effect the magnetic coupling coefficient K 3 can be ignored. Therefore, for the inductor 206 , magnetic coupling generated by the inductor 208 can be ignored, and the inductor 214 and inductor 216 can be adjusted to have a same distance with the inductor 206 . Therefore, the inductor 214 and inductor 216 can induce magnetic fields on the inductor 206 with a same magnitude but a upwards through paper direction and a downwards through paper direction, respectively, such that corresponding induced currents on the inductor 206 are cancelled with each other. By the same token, induced currents on the inductor 208 , 214 and 216 can also be cancelled. As a result, the present invention can adjust induced currents to be cancelled with each other, so as to reduce IQ imbalance, and minimize layout area. Similarly, as shown in FIG. 3B , coil winding directions of the inductor 206 and 216 are clockwise, and thus magnetic field directions are downwards through paper, while coil winding directions of the inductor 208 and 214 are counterclockwise, and thus magnetic field directions are upwards through paper. Therefore, the above effect can also be achieved, and is not narrated hereinafter.
Please refer to FIG. 4A and FIG. 4B . FIG. 4A is a schematic diagram of IQ imbalance magnitude of the quadrature amplifier 100 shown in FIG. 1A . FIG. 4B is a schematic diagram of IQ imbalance magnitude of the amplifier 200 shown in FIG. 2A . FIG. 4A and FIG. 4B are obtained by measuring a difference between in-phase positive signal and quadrature-phase positive signal at different frequencies. Ideally, there are only signals at carrier frequency minus baseband frequency, i.e. points D, F. In practice, IQ imbalance magnitude is obtained by measuring a difference between signals at carrier frequency minus baseband frequency and signals at carrier frequency plus baseband frequency, i.e. points E, G, wherein lower difference indicates worse IQ imbalance. As can be seen from FIG. 4A and FIG. 4B , IQ imbalance magnitude of FIG. 4A is 37.7 dB, and IQ imbalance magnitude of FIG. 4B is 52.3 dB. Therefore, the present invention gain extra 14.6 dB of IQ imbalance magnitude than the prior art. Noticeably, in normal communication systems, IQ imbalance magnitude is required to be higher than 40 dB. As a result, other than adjusting induced currents to be cancelled with each other, so as to reduce IQ imbalance and minimize layout area, the present invention can more comply with requirements of communication systems than the prior art.
Noticeably, the spirit of the present invention is to adjust relative positions and coil winding directions of inductors inside an amplifier, to cancel magnetic coupling between different internal paths, so as to reduce IQ imbalance. Those skilled in the art should make modifications or alterations accordingly which belong to the scope of the present invention. For example, the amplifier 200 is not limited to generate in-phase signals and quadrature-phase signals with 90 degree phase difference, and can to generate signals with other fixed phase differences, such as 45 degree or 135 degree. The amplifier 200 is also not limited to only include the in-phase path and the quadrature-phase path, and can include more than two paths with a specific phase difference. An amount of LC tanks is not limited to four, and can be any amount. All modifications or alterations belong to the scope of the present invention, as long as magnetic coupling between different internal paths can be cancelled by adjusting relative positions and coil winding directions of internal inductors of LC tanks of the amplifier.
In addition, relative positions of the inductors inside the amplifier 200 are not limited to the above description that the in-phase path and the quadrature-phase path are cross. In other embodiments, the in-phase path and the quadrature-phase path can be in parallel as well, which can still cancel magnetic coupling between different internal paths by adjusting relative positions and coil winding directions inside inductors of the amplifier.
For example, please refer to FIG. 5A and FIG. 5B . FIG. 5A is a schematic diagram of an amplifier 500 according to an embodiment of the present invention. A difference between the amplifier 500 and the amplifier 200 is that the amplifier 500 the in-phase path and the quadrature-phase path are in parallel, i.e. differential amplifiers 502 , 504 and inductors 506 , 508 are in parallel with differential amplifiers 510 , 512 and inductors 514 , 516 . Operating principles of the amplifier 500 are similar to those of the amplifier 200 , and are not narrated hereinafter. FIG. 5B is a schematic diagram of magnetic coupling between inductors 506 , 508 , 514 and 516 shown in FIG. 5A . K 1 ′ is a magnetic coupling coefficient between the inductors 506 and 514 or the inductors 508 and 516 , K 2 ′ is a magnetic coupling coefficient between the inductors 506 and 508 or the inductors 514 and 516 , and K 3 ′ is a magnetic coupling coefficient between the inductors 506 and 516 or the inductors 514 and 508 . K 1 ′, K 2 ′ and K 3 ′ are magnetic coupling coefficients between inductors, respectively. In such a condition, since IQ imbalance between signals with a same phase is small, an effect the magnetic coupling coefficient K 2 ′ can be ignored. Therefore, as long as relative distances and the coil winding directions of the inductors 506 , 508 , 514 and 516 are properly adjusted, induced currents generated by magnetic coupling can be cancelled with each other, so as to reduce IQ imbalance.
Please continue to refer to FIG. 6A and FIG. 6B , which are schematic diagrams of the inductors 506 , 508 , 514 and 516 shown in FIG. 5A having different coil winding directions. In FIG. 6A , coil winding directions of the inductors 506 and 514 are clockwise, and thus magnetic field directions are downwards through paper, while coil winding directions of the inductors 508 and 516 are counterclockwise, and thus magnetic field directions are upwards through paper. In such a condition, since IQ imbalance between signals with a same phase is small, the effect the magnetic coupling coefficient K 2 ′ can be ignored. Therefore, in order to make the magnetic coupling coefficients K 1 ′ and K 3 ′ to be cancelled with each other, the inductors 506 , 508 , 514 and 516 can be arranged corresponding to four vertices of a rhombus or a distance H′ between the inductors 506 , 514 can be lengthened, to induce magnetic fields with a same magnitude but opposite directions, such that corresponding induced currents are cancelled with each other. Similarly, FIG. 6B is another schematic diagram of coil winding directions, and is similar to the above description.
Therefore, a method for the amplifier 200 to cancel magnetic coupling can be summarized into is a process 70 . As shown in FIG. 7 , the process 70 includes following steps:
Step 700 : Start.
Step 702 : Form the inductors 206 and 208 in the in-phase path.
Step 704 : Form the inductors 214 and 216 in the quadrature-phase path.
Step 706 : End.
Noticeably, the inductors 206 , 208 , 214 , 216 form inductors of LC tanks, respectively. By adjusting the relative distances and the coil winding directions of the inductors 206 , 208 , 214 and 216 , induced currents on the inductors generated by magnetic coupling can be cancelled with each other. Detailed description can be derived by referring the above description, and is not narrated hereinafter.
In the prior art, a distance between an in-phase path and a quadrature-phase path has to be lengthened, to reduce induced currents, so as to reduce IQ imbalance. In comparison, the present invention increases an amount of LC tanks on the in-phase path and the quadrature-phase path, respectively, and then adjusts relative distances and coil winding directions of inductors of the LC tanks. Therefore, induced magnetic fields on the inductors can be cancelled with each other, to reduce induced currents, and thus reduce IQ imbalance. As a result, the present invention can reduce IQ imbalance with small layout area.
To sum up, the present invention cancels magnetic coupling by increasing and adjusting LC tanks, and thus can effectively reduce IQ imbalance with small layout area.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention.
|
A method for cancelling magnetic coupling in an amplifier is disclosed. The amplifier includes a first path and a second path for outputting a first signal and a second signal, respectively, and the first signal and the second signal have a specific phase difference. The method includes forming a first LC tank and a second LC tank in the first path, and forming a third LC tank and a forth LC tank in the second path.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The application claims priority from U.S. Provisional Patent Application No. 61/394,774, filed on Oct. 20, 2010, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to operation of a social introduction and communication service. Specifically, the invention relates to initiating an electronic conversation between a first user and at least one other user selected by the first user before or after filtering transmitted identifying information according to attributes selected by the located user. The first user may seek other users present at a particular location.
[0003] Electronic matching services exist, often via networks, to identify and bring together two or more people that somehow indicate a desire to initiate a conversation for social, business, or other reasons. Many such services attempt to make matches based on interests, beliefs, goals, background, history, race, ethnicity, and personalities. However, these matching services do not often account for advance on-site assessments made from observations at particular locations.
[0004] Upon observing a person (perhaps via images of a person), many matching services allow users to communicate via telephone, by email, text message, web services, or even in person. However, such matching services do not have systems or facilities to permit users to observe other users live, perhaps interacting with other users. Also, not everyone is comfortable communicating with a new person openly, for reasons of shyness, confidentiality, avoidance of encouraging stalking behavior, and other reasons. Many users may seek to initiate conversations without the embarrassment of public rejection in a bar, restaurant, concert location, classroom, or other venue. Thus, many users are desirable of engaging in a gradual communication before engaging in a more personal introduction to strangers.
[0005] Portable devices are increasingly used for multiple tasks that range from telephony to video to computing to audio and other entertainment and instructional uses. Portable devices may be used to facilitate communication, including via a communication service. Such devices may include mobile telephones, personal digital assistants (PDAs), portable video/music players, electronic books, electronic book readers, tablet computers, portable gaming devices, and the like. Some of such devices include the iPad (trademarked by Apple, Inc.), the iPod (trademarked by Apple, Inc.), the iPhone (trademarked by Apple, Inc.), the BlackBerry (trademarked by RIM, Inc.), the Android (trademarked by Google, Inc.), Android-based devices, and other portable devices.
[0006] It would be advantageous to provide a communications service that would include one or more of the features of 1) detecting (or establishing or allowing entry of) a user's location; 2) assigning identifying information to the user (or allowing identifying information to be entered by a user); 3) assigning identifying information to other users (or allowing users to enter identifying information) at the approximate same location of the located user; 4) filtering the transmitted identifying information according to attributes selected by the located user; and 5) initiating an electronic conversation between the located user and at least one of the other users selected by the located user.
SUMMARY OF THE INVENTION
[0007] In one aspect of the present invention, a method for operating a communications service comprises determining the location of users, via geo-positional searching (GPS), WiFi signals, signal triangulation, and/or user registration; assigning identifying information to the located user; communicating with a computer server to store the user location and assigned identifying information; retrieving a list from a computer of other users at the approximate same location of the located user; assigning identifying information to the other users at the approximate same location of the located user; transmitting the identifying information of the other users to the located user; filtering the transmitted identifying information according to attributes selected by the located user; initiating an electronic conversation between the located user and at least one of the other users selected by the located user. The determining step may comprise geo-positional searching (GPS), signal triangulation, WiFi signals, navigational methods, and/or user registration.
[0008] A located user may provide a response to an option to ignore, respond to, or block contact with one or more of the other users. One may desire to encounter new potential users and incorporate the new users into a list of contacts for further communication. New users may be added to a list of users while at a particular location or at a plurality of locations.
[0009] In another aspect of the present invention, the communicating step occurs via one or more of MMS, SMS, text messaging, Internet, website, radio, telephone, telegraph, television, video, or other suitable forms of communication.
[0010] In a further aspect of the present invention, the electronic conversation in the initiating step occurs via one or more of MMS, SMS, text messaging, Internet, website, radio, telephone, telegraph, television, video display, or other suitable methods.
[0011] In a still further aspect of the present invention, the located user provides a response to an option to ignore, respond to, or block contact (temporarily or permanently) with one or more of the other users. The users may be one of members of a created virtual community network and/or non-members of a created virtual community network.
[0012] In yet another aspect of the present invention, an apparatus may comprise a processor; the processor configured to receive an invitation from an inviter to execute at least a part of a software application; execute at least part of the software application; and reveal an identifying characteristic of the inviter to an invitee/challengee. The identity of the inviter may be revealed.
[0013] The invention may further comprise receiving an invitation from an inviter. Also, an inviter may reveal an identifying characteristic of the inviter to an invitee. If desired, the invitee may reveal an identifying characteristic of the invitee to the inviter, Inviters and invitees may choose what and how much of any information (such as identifying characteristics) to provide into the system and/or to other users. Various users may reveal information regarding certain users to other users.
[0014] Several social media arrangements rely on a user communicating with an established group of “friends” or users. While the present invention permits ongoing communication with lists of users and associates, the present invention also facilitates interacting with others that are possibly unacquainted with a particular user. Invitations, challenges, and other communications may facilitate introductions using the present invention.
[0015] The processor may be further configured to receive a request to prepare an invitation/challenge to an additional invitee/challengee; prepare the invitation/challenge to the additional invitee/challengee; submit a request to transmit the invitation/challenge to the additional invitee/challengee; and monitor the status of the invitation/challenge.
[0016] The apparatus may further comprise a challenge generator that generates a challenge to elicit a response from a first viewer, one or more second viewers, one or more third viewers and one or more nth viewers; a challenge-response module that determines whether the first viewer, the one or more second viewers, the one or more third viewers, and the one or more nth viewers have entered a response to the challenge to confirm whether the challenge has been reviewed by the first viewer, the one or more second viewers, the one or more third viewers, and the one or more nth viewers respectively; and a report generation module that generates a response report for each of the first viewer, the one or more second viewers, the one or more third viewers, and the one or more nth viewers based on the response from the first viewer the one or more second viewers, the one or more third viewers, and the one or more nth viewers.
[0017] In still yet a further aspect of the present invention, a computer program product comprising computer-readable program code portions may comprise a first program code portion configured to receive notification of an invitation via a software application; a second program code portion configured to prepare an invitation; and a third program code portion configured to transmit the invitation to an invitee/challengee to allow the invitee/challengee to access at least a portion of the software application.
[0018] The third program code portion may further comprise a program code portion to transmit the invitation via short message service message, multimedia messaging service message, electronic mail, or other messaging protocol. The third program code portion may be configured to reveal an identifying characteristic of the inviter/challenger to an invitee/challengee. The computer program product may further comprise a fourth program code portion for confirming viewing of the invitation/challenge by the invitee/challengee.
[0019] These and other aspects, objects, features and advantages of the present invention, are specifically set forth in, or will become apparent from, the following detailed description of an exemplary embodiment of the invention when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic block diagram of a mobile communication device, according to an embodiment of the present invention;
[0021] FIG. 2 is a block diagram of an apparatus for screening communications, according to an embodiment of the present invention;
[0022] FIG. 3 is a block diagram of network components, according to an embodiment of the present invention;
[0023] FIG. 4 is a flowchart of a method, according to another embodiment of the present invention;
[0024] FIG. 5 is a flowchart of another method, according to another embodiment of the present invention; and
[0025] FIG. 6 is a flowchart of yet another method, according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
[0027] Referring now to the drawings in detail, wherein like reference characters refer to like elements, there is shown in FIG. 1 a block diagram of a mobile communication device 10 that may benefit from embodiments of the present invention. It should be understood, however, that the mobile communication device shown and hereinafter described is merely illustrative of one type of electronic device that may benefit from embodiments of the present invention and, therefore, should not be taken to limit the scope of the present invention. While several embodiments of an electronic device are illustrated and will be hereinafter described for purposes of example, other types of electronic devices, such as mobile telephones, mobile computers, portable digital assistants (PDAs), pagers, laptop computers, desktop computers, tablet computers gaming devices, televisions, and other types of electronic systems, may employ the present invention.
[0028] As shown, the mobile communication device 10 may include an antenna 12 in communication with a transmitter 14 and a receiver 16 . The mobile communication device 10 may also include a controller 20 or other processor that provides signals to and from the transmitter and receiver, respectively. These signals may include signaling information according to an air interface standard of an applicable cellular or other mobile system, and/or any number of different wireless networking techniques, comprising but not limited to Wireless-Fidelity (Wi-Fi), wireless LAN (WLAN) techniques such as IEEE 802.11 and/or the like. Additionally, these signals may include speech data, user-generated data, user-requested data, and/or the like. The mobile communication device 10 may be capable of operating with one or more air interface standards, communication protocols, modulation types, access types, and/or the like. More particularly, the communication device 10 may be capable of operating according with various first generation (1G), second generation (2G), 2.5G, third-generation (3G) communication protocols, 3.9G, fourth-generation (4G) communication protocols, and/or the like. For example, the mobile communication device 10 may be capable of operating in accordance with 2G wireless communication protocols IS-136 (TDMA), GSM, and IS-95 (CDMA). For example, the mobile communication device 10 may be capable of operating in accordance with 2.5G wireless communication protocols GPRS, EDGE, or the like. Further, for example, the mobile terminal may be capable of operating in accordance with 3G wireless communication protocols such as UMTS, CDMA2000, WCDMA and TD-SCDMA. The mobile communication device 10 may be additionally capable of operating in accordance with 3.9G wireless communication protocols such as LTE or E-UTRAN. Additionally, for example, the mobile communication device 10 may be capable of operating in accordance with fourth-generation (4G) wireless communication protocols or the like as well as similar wireless communication protocols that may be developed in the future.
[0029] Some Narrow-band Advanced Mobile Phone Systems (VAMPS), as well as Total Access Communication Systems (TACS), and mobile communication devices may also benefit from embodiments of this invention, as should dual or higher mode phones (e.g., digital/analog or TDMA/CDMA/analog phones). Furthermore, the mobile communication device 10 may be capable of operating according to Wireless Fidelity (Wi-Fi) protocols. It is understood that the controller 20 may comprise the circuitry desirable for implementing audio and logic functions of the mobile terminal 10 . In one example, the controller 20 may comprise a digital signal processor device, a microprocessor device, an analog-to-digital converter, a digital-to-analog converter, and/or the like. Any control and signal processing functions of the mobile communication device 10 may be allocated between these devices according to the respective capabilities. The controller may additionally comprise an internal voice coder (VC) 20 a, an internal data modem (DM) 20 b, and/or the like. Furthermore, the controller may comprise functionality to operate one or more software programs, which may be stored in memory. For example, the controller 20 may be capable of operating a connectivity program, such as a Web browser. The connectivity program may allow the mobile communication device 10 to transmit and receive Web content, such as location-based content, according to a protocol, such as Wireless Application Protocol (WAP), hypertext transfer protocol (HTTP), and/or the like. The mobile communication device 10 may be capable of using a Transmission Control Protocol/Internet Protocol (TCP/IP) to transmit and receive Web content across the Internet.
[0030] The mobile communication device 10 may also comprise a user interface including a conventional earphone or speaker 24 , a ringer 22 , a microphone 26 , a display 28 , a user input interface, and/or the like, which may be coupled to the controller 20 . Although not shown, the mobile communication device 10 may comprise a battery for powering various circuits related to the mobile communication device 10 , for example, a circuit to provide mechanical vibration as a detectable output. The user input interface may comprise devices allowing the mobile communication device 10 to receive data, such as a keypad 30 , a touch display (not shown), a joystick (not shown), and/or other input device. In embodiments including a keypad, the keypad may comprise conventional numeric (0-9) and related keys (#, *, and/or other keys for operating the mobile terminal.
[0031] As shown in FIG. 1 , the mobile communication device 10 may also include one or more means for sharing and/or obtaining data. For example, the mobile communication device 10 may comprise a short-range radio frequency (RF) transceiver and/or interrogator 64 so data may be shared with and/or obtained from electronic devices in accordance with RF techniques. The mobile communication device 10 may comprise other short-range transceivers, such as, for example an infrared (IR) transceiver 66 , a Bluetooth™ (BT) transceiver 68 operating using Bluetooth™ brand wireless technology developed by the Bluetooth™ Special Interest Group, and/or the like. The Bluetooth transceiver 68 may be capable of operating according to Wibree™ radio standards. In this regard, the mobile communication device 10 and, in particular, the short-range transceiver may be capable of transmitting data to and/or receiving data from electronic devices within a proximity of the mobile terminal, such as within 10 meters or more, for example. Although not shown, the mobile communication device 10 may be capable of transmitting and/or receiving data from electronic devices according to various wireless networking techniques, including Wireless Fidelity (Wi-Fi), WLAN techniques such as IEEE 802.11 techniques, and/or the like.
[0032] The mobile communication device 10 may comprise memory, such as a subscriber identity module (SIM) 38 , a removable user identity module (R-UIM), and/or the like, which may store information elements related to a mobile subscriber. In addition to the SIM, the mobile communication device 10 may comprise other removable and/or fixed memory. In this regard, the mobile terminal may comprise volatile memory 40 , such as volatile Random Access Memory (RAM), which may comprise a cache area for temporary storage of data. The mobile communication device 10 may comprise other non-volatile memory 42 , which may be embedded and/or may be removable. The non-volatile memory may comprise an EEPROM, flash memory, and/or the like. The various memories may store one or more software programs, instructions, pieces of information, data, and/or the like which may be used by the mobile communication device 10 for performing functions of the mobile communication device 10 . For example, the memories may comprise an identifier, such as an international mobile equipment identity (IMEI) code, capable of uniquely identifying the mobile communication device 10 .
[0033] Referring now to FIG. 2 , an example apparatus 200 for providing software application invitations is described. Apparatus 200 may be embodied as a network element, e.g. a server, or other network device including, for example, a mobile terminal, such as mobile communication device 10 of FIG. 1 . The apparatus 200 may include, or otherwise be in communication with, a processor 205 , a user interface 215 , a communication interface 220 , and/or a memory device 210 . The memory device 210 may include, for example, volatile and/or non-volatile memory (e.g., volatile memory 40 and/or non-volatile memory 42 ). The memory device 210 may be accessed via a local network or otherwise available remotely. In other embodiments, the memory device 210 may be separate from apparatus 200 but may be accessed by apparatus 200 locally, such as, for example, a memory card, Secure Digital (“SD”) card, and/or the like, via a local network, or otherwise available remotely. The memory device 210 may be configured to store information, data, applications, instructions, or the like for enabling the apparatus to carry out various functions in accordance with example embodiments of the present invention.
[0034] For example, the memory device 210 could be configured to buffer input data for processing by the processor 205 . Additionally or alternatively, the memory device 210 may be configured to store instructions for execution by the processor 205 . As another alternative, the memory device 210 may be one of a plurality of databases that store information in the form of static and/or dynamic information, for example, in association with user contacts, one or more response tables, a log of software applications invitations, and/or the like.
[0035] The processor 205 may be embodied in various ways. For example, the processor 205 may be embodied as various processing means including a microprocessor, a coprocessor, a controller (e.g., controller 30 from FIG. 1 ), or various other processing elements including integrated circuits such as, for example, an ASIC (application specific integrated circuit) or FPGA (field programmable gate array). In another example embodiment, the processor 205 may be configured to execute instructions stored in the memory device 210 or otherwise accessible to the processor 205 .
[0036] The user interface 215 may be in communication with the processor 205 to receive an indication of a user input at the user interface 215 and/or to provide an audible, visual, mechanical, or other output to the user. The user interface 215 may include, for example, a keyboard, a mouse, a joystick, a touch screen display, a conventional display, a microphone, a speaker, or other input/output mechanisms. For example, in an embodiment in which the apparatus 200 is embodied as a mobile terminal (e.g., the mobile communication device 10 of FIG. 1 ), the user interface 215 may include, among other devices or elements, any or all of the speaker 24 , the ringer 22 , the microphone 26 , the display 28 , and the keyboard 30 . In an exemplary embodiment in which the apparatus 200 is embodied as a server, the user interface 215 may be limited, or even eliminated.
[0037] The communication interface 220 may be embodied as any device or means embodied in either hardware, software, or a combination of hardware and software that is configured to receive and/or transmit data from/to a network and/or any other device or module in communication with the apparatus 200 . The communication interface 220 may include, for example, an antenna, a transmitter, a receiver, a transceiver, a network card, network adapter, network interface card and/or supporting hardware or software for enabling communications with network 225 , which may be any type of wired or wireless network. The communication interface 220 may enable the receipt and transmission of communications using remote devices (e.g., a contacts server 240 , a user platform 245 and 250 , or the like). For example, in an embodiment in which the apparatus 200 is embodied as a mobile terminal (e.g., the mobile communication device 10 of FIG. 1 ), the communication interface 225 may include, among other devices or elements, any or all of an antenna 12 , a transmitter 14 , a receiver 16 , a radio frequency (RF) transceiver and/or interrogator 64 , an infrared (IR) transceiver 66 , a Bluetooth™ (BT) transceiver 68 , an internal voice coder (VC) 20 a, and an internal data modem (DM) 20 b.
[0038] As used herein, “communications” and “communication events” may be used interchangeably and may include, but are not limited to, telephone calls, short message service (SMS) messages, multimedia messaging service (MMS) messages, e-mails, Internet Protocol communication and/or the like, and transfer or other sharing of files between the apparatus 200 and the remote devices. Sometimes as used herein, the generic term “messages” may be used to refer to SMS messages, MMS messages, e-mails, text messages, file transfers and/or the like. As such, via the communication interface 220 and the network 225 , the apparatus 200 may communicate with the contacts server 240 , the user platform 245 , and/or the user platform 250 .
[0039] As noted above, the apparatus 200 may be configured to communicate with a contacts server 240 . The contacts server 240 may be any type of computing device for storing, retrieving, computing, transmitting, and receiving data. The contacts server 240 may include a memory device, a processor, and a communication interface for communicating with the network 225 . In some embodiments, the contacts server 240 may be a web server, database server, file server, or the like. According to various embodiments, the contacts server 240 may be a storage location for user contacts. In this regard, a user may upload one or more user contacts to the contacts server 240 via, for example, network 225 . For example, one or more user contacts associated with the user platform 245 and/or the user platform 250 may be uploaded to the contacts server 240 via network 225 . Conversely, a user may update one or more user contacts maintained on the contacts server 240 via, for example, network 225 , and download/transfer to the user platform 245 , via, for example, network 225 .
[0040] In one example, user contacts associated with the user platform 245 and/or the user platform 250 maintained on the contacts server 240 may be updated and then downloaded back to the user platform 245 and/or the user platform 250 . Similarly, a user may exchange or share one or more user contacts with another user, using respective user platforms 245 and 250 , in other words uploading or updating one or more user contacts between the user platforms, via, for example, network 225 . As such, and as described below, one or more user contacts may be synchronized with, for example, contacts server 240 and/or between user platforms 245 and/or 250 . Further, one or more user contacts may be received from the contacts server 240 by various network entities including apparatus 200 .
[0041] The user platforms 245 , 250 may also be of any type of device for storing, retrieving, computing, transmitting and receiving data. In some embodiments, user platforms 245 , 250 may be embodied as a mobile communication device 10 of FIG. 1 or the like. Alternatively, the user platforms may be fixed, such as in instances in which a work station serves as a user platform. User platforms may be associated with one or more user contacts such that a user contact may be used to direct communications to the user platforms and a user of the user platform. In some embodiments, user contacts may direct communications to a central holding location (e.g., a server) that may be accessed by a user via user platforms 245 , 250 . For example, email may be directed by a user contact to a server for holding until a user can access the server via a user platform and retrieve the email. In the alternative, email may be directed to a server for holding by a user contact and subsequently transferred to a user platform. User platforms 245 , 250 are representative of a plurality of user platforms, and as such any number of user platforms may be included in FIG. 2 . In some embodiments, via the user platforms 245 , 250 , a user may access an example online service such as, but not limited to, a website, a social networking website, a website dedicated to users of software applications such as, for example, a game website, a blog website, a web feed, a widget, or the like, using a browser, a dedicated application, or the like.
[0042] User platform 250 , as well as any other user platform, may also be associated with a phonebook 255 . The phonebook 255 may include data including user contacts and additional associated information. The phonebook 255 may be stored on a memory device that is included with the user platform 255 or external to the user platform 250 , similar to contacts server 240 . As described below, the data within the phonebook 255 may be synchronized with, for example, a contacts server 240 .
[0043] The apparatus 200 also includes a response receiver 230 , a response comparator 232 , an invitation generator 234 , and a response table generator 236 , which may be any means or device embodied in hardware, software, or a combination of hardware and software that is configured to carry out the respective functions as described herein. In an example embodiment, the processor 205 may include, or otherwise control the response/challenge receiver 230 , the response/challenge comparator 232 , the invitation/challenge generator 234 , and the response/challenge table generator 236 . In various example embodiments, the response/challenge receiver 230 , the response/challenge comparator 232 , and the invitation/challenge generator 234 may reside on a server, or other network device including a mobile terminal, such as mobile communication device 10 of FIG. 1 .
[0044] The response/challenge receiver 230 may be configured to receive one or more responses accomplished by a user, and as such, may be embodied by various means, including user interface 215 , communication interface 220 , the processor 205 , and/or the like. In this regard, a user may access and execute a software application, and accomplish one or more response(s)/challenges as a result of their execution of the software application. As used herein, “software application”, “software”, or “application” may be used interchangeably to refer to a game application, a word or other data processing application, media applications, media files (e.g., music, video, picture, podcast files, and/or the like) and/or the like. A software application may be organized by a developer of the software application to provide a user with an opportunity to accomplish various different responses. The software application may be accessed and/or executed using user platforms 245 and/or 250 . In some embodiments, the software application may be accessed through an online service. In this regard and as an example, a user may access an online service to execute a software application, such as playing a video game, running a social media application, or other applications.
[0045] In this regard, and referring now to FIG. 3 , an embodiment of a system in accordance with aspects of the present invention is illustrated. The system 300 of
[0046] FIG. 3 may include a service application 302 , a front-end service 312 , a back-end service 322 , a back-end storage device 332 , and a front-end storage device 342 . The service application 302 , the front-end service 312 , the back-end service 322 , the back-end storage device 332 , and the front-end storage device 342 may be interconnected via the illustrated network 325 , which may operate in similar manner to network 225 .
[0047] The back-end service 322 may be embodied as or provided by apparatus 200 and the back-end service 322 may be an online service. The back-end storage device 332 and the front-end storage device 342 may operate in similar manner to the memory device 210 , as discussed herein above. The back-end storage device 332 may store one or more response/invitation tables, invitations, and/or the like. The front-end storage device 342 may store information associated with the user, the user's contacts, other users of the software application, and/or the like.
[0048] The service application 302 may be a software or hardware application residing and operating on a platform, such as a computer, mobile terminal, or the like, that may be used to interact with the front-end service 312 , the back-end service 322 , and/or allow the front-end service 312 and the back-end service 322 to interact with each other. In some embodiments, one or more of the front-end service 312 , the back-end service 322 , the front-end storage device 342 , and the back-end storage device 332 may reside and operate on a platform, such as a mobile terminal, computer, and/or the like. In some embodiments, the service application 302 may reside and operate on the apparatus 200 , the user platforms 245 , 250 , or the like, and may operate in similar manner to apparatus 200 , the user platforms 245 , 250 , or the like. The service application 302 may be downloaded to and/or installed on the platform. Via the service application 302 , the front-end service 312 and the back-end service 322 may interact with each other to send and receive data, such as challenges/responses, user information, user contacts, and/or the like. The service application 302 may facilitate the gathering and/or storage of challenges/responses, usage attributes and/or user contacts for subsequent transmission to the front-end service 312 and/or the back-end service 322 .
[0049] The service application 302 may also include authentication means to provide security features during the interaction between the front-end service 312 and the back-end service 322 . The authentication means may be embodied as the processor 205 , the front-end service 312 , the back-end service 322 , and/or the like, and, in one embodiment, may include computer instructions executed by one or more of the foregoing components. For example, the back-end service 322 may authenticate itself via the authentication means before exchanging information and/or accessing information maintained on the front-end storage device 342 , and vice versa. Upon verification, the back-end service may be provided with access to, and allowed to exchange information with the front-end service 312 , and vice versa. In some embodiments, the back-end storage device 332 and the front-end storage device 342 may be embodied in one storage device that may operate in similar manner to the memory device 210 .
[0050] Referring back to FIG. 2 , upon executing the software application, the user may receive or send a response/challenge. For example, the user may reach a certain user or users, provide challenge communications (e.g., “are you available?”), complete a certain level in a hierarchy of users, join special groups of users, gain a certain amount of familiarity, experience, proficiency level, and/or the like. The response/challenge receiver 230 may be configured to receive and/or retrieve one or more responses or challenges accomplished by a user. The one or more responses/challenges may be received and/or retrieved immediately upon being sent by a user or upon termination of the execution of the application by the user or by the application. In some embodiments, the response/challenge receiver 230 may be configured to store the one or more responses/challenges of the user in the memory device 210 to be retrieved at a later time to generate one or more invitations to the user's contacts to execute a portion of the software application.
[0051] In addition to receiving and/or retrieving the one or more responses of the user, the response/challenge receiver 230 may also receive and/or retrieve information regarding the software application to identify the response/challenge table associated with the software application. In some embodiments, one or more response/challenge tables may be stored in the memory device 210 .
[0052] FIG. 2 , the response/challenge comparator 232 may be configured to compare the one or more responses/challenges received and/or retrieved by the response receiver 230 with the entries of the response/challenge table identified by the response/challenge receiver 230 to identify the options available in generating invitations to the user's contacts. The response/challenge comparator 232 may receive one or more responses/challenges, compare the one or more received responses/challenges with the entries in the response/challenge table, and determine which portion(s) of the application and/or additional attributes or information related to the application to send via invitations based at least in part on the comparison. The response/challenge comparator 232 may be embodied by various means including the processor 205 , which may execute computer instructions stored, for example, in memory device 210 . In some embodiments, the response/challenge comparator 232 may also receive and/or retrieve information regarding the software application to identify the response/challenge table associated with the software application. The response/challenge comparator 232 may receive and/or retrieve the one or more responses/challenges received and/or retrieved by the response/challenge receiver 230 and compare them to the entries of the identified response/challenge table. The response/challenge comparator 232 may identify one or more entries corresponding to the one or more responses/challenges and thus determine the one or more trial versions, activation codes, number of times to send invitations to execute the software application, and/or any additional information associated with the one or more responses/challenges of the user in executing the software application.
[0053] The invitation/challenge generator 234 may be configured to generate one or more invitations and/or challenges based at least in part on the one or more entries identified by the response comparator 232 . The invitation/challenge generator 234 may be embodied by various means including the processor 205 , which may execute computer instructions stored, for example, in memory device 210 . Upon accomplishing a response/challenge, the user may receive a request from the invitation/challenge generator 234 to send a portion of or the entire application as executed thus far to the user's contacts or potential contacts. The request may be provided immediately after the response, after the software application indicates to the user a termination of the execution or after the user terminates execution of the application. The user may desire to send one or more invitations at any moment such as, for example, upon receiving the requests, after terminating the execution of the application or after reaching a termination point of the application for a particular execution session. In other embodiments, the user may suspend the execution of the application, send one or more challenges or invitations, and then continue the execution of the application.
[0054] The challenge or invitation may be generated based at least in part on the one or more entries in the response table corresponding to the one or more responses of the user or challenger/inviter. Generating an invitation or challenge may also be based at least in part on the submission of various information from the user or challenger/inviter. As such, the user or challenger/inviter may be prompted by the invitation/challenger generator 234 to submit various types of information. In this regard, the user or challenger/inviter may be requested to submit a shown challenge, invitation, or proposal. As used herein, a “challenge” may refer to challenging one or more invitees to exceed or accomplish the response accomplished by the inviter. An invitation” may refer to inviting one or more users to challenge one or more users. For example, the inviter/challenger may have completed a certain level in the application in a certain amount of time. As such, the inviter/challenger may challenge or invite the one or more invitees or users to complete the same level in the same or better time. As another example, the inviter/challenger may have accrued a certain amount of points. As such, the inviter/challenger may invite/challenge the one or more invitees or other users to accrue the same or more amount of points. Additionally, the user or invitee/challenger may be requested to submit a hidden message to be displayed to the one or more invitees/challengers upon completion of the challenge/invitation. In some embodiments, the message may be gradually displayed as the invitee is completing the challenge. The message may include the identity of the inviter/challenger and may be any message desired by the inviter/challenger. In some embodiments, there may be a message in the event the invitee completes the challenge. In other embodiments, another message may be presented in the event the invitee/challenger fails to complete the challenge after a predetermined number of attempts. The present invention may be used for advertisement, marketing, education, and other purposes.
[0055] Further, the inviter/challenger may be requested by the invitation/challenge generator 234 to submit the contacts to whom the invitations to execute the application may be sent. As discussed above, the user or inviter may be accessing the application from an online service using user platforms 245 and/or 250 . In this regard, the invitation/challenge generator 234 may be configured to access the phonebook 255 of the user platform 250 and/or 245 . As such, the one or more invitees may be selected from the contacts stored in the phonebook 255 . In other embodiments, the invitation/challenge generator 234 may be configured to access the contacts of the user, challenger, or inviter stored on a remote server, such as, for example, contacts server 240 . In different embodiments, the user or inviter may be accessing the application from a website, such as, for example, a social network website.
[0056] The invitation/challenge generator 234 may be configured to access the contacts of the user or inviter maintained by the social network website. The invitation/challenge generator 234 may retrieve all necessary information regarding one or more contacts or potential contacts of the user (e.g. name, telephone number, email address, and/or the like) from the social network website and transfer the information to apparatus 200 . The information may be stored in a temporary storage location on memory device 210 and/or the like. The invitation/challenge generator 234 may then use the information to generate the invitations/challenges. In other embodiments, the invitation/challenge generator 234 may generate the one or more invitations/challenges, as described in further detail, without the information of the contacts of the user, and forward the invitations/challenges to the social network website. The user, challenger, or inviter may then select the one or more individual contacts or group of contacts to send the invitations/challenges,
[0057] In the alternative, the social network website may automatically send the invitations and/or challenges. The invitation/challenge generator 234 may be configured to include information that may allow the social network website to automatically send the invitations/challenges. For example, the user may have a particular group or a sub-group on the social network website. As such, the invitation/challenge generator 234 may be configured to include information related to those groups. In further embodiments, the user may be accessing the software application from an online service dedicated to other users of the application, related or unrelated applications, and/or the like. In this regard, a similar approach described above with respect to the social network website may be applicable. As such, the invitation/challenge generator 234 may be configured to access these users as user's contacts or potential contacts. The invitation/challenge generator 234 may be configured to access and/or retrieve the user's contacts at various moments, such as, for example, upon the user accessing the software application, during the execution of the application, upon accomplishing an invitation, response or challenge, after terminating the execution of the application, and/or the like. Upon retrieving a selected user's contacts, the user may be requested to choose one or more contacts to receive the one or more invitations. As discussed above, the number of times to send the invitations is based at least in part on the response of the challenger/inviter or challengee and/or invitee as indicated in the response table. As such, the invitation/challenge generator 234 may set the maximum of invitations/challenges that may be sent to the user's contacts.
[0058] In some embodiments, the user may choose to send a default invitation and/or challenge and as such, may not submit any customized information. In this regard, the invitation/challenge generator 234 may submit all the information necessary to generate the invitation/challenge. Once the information has been received, the invitation/challenge generator 234 may proceed to compile the one or more invitations/challenges and send them to one or more invitees, challengees (challenge recipients), or a user's contacts. The one or more invitations/challenges may be embedded with information related to the user or inviter such as, for example, name, e-mail address, other identifiers, and/or the like. The one or more invitations/challenges may comprise a hyperlink and/or other means to access the trial version of the software application.
[0059] The invitation/challenge generator 234 may determine an expiration time for the invitation/challenge. In other embodiments, the invitations/challenges and/or the trial versions or portions of the software application may be indefinitely valid. The one or more invitations/challenges may be sent to one or more user's contacts using various communications methods such as, for example, short message service (SMS) message, multimedia messaging service (MMS) message, e-mail, instant messaging, other messaging protocol, and/or the like. The invitations may be directed by the invitation/challenge generator 234 to a server for holding until the one or more invitees can access the server via a user platform and retrieve the invitation/challenge. In the alternative, the invitation/challenge may be directed to a server for holding and subsequently transferred to a user platform of the invitees/challengees.
[0060] The invitation/challenge generator 234 may also maintain one or more records associating the user or inviter/challenger with the one or more invitations/challenges sent, along with additional information related to the one or more invitations/challenges and/or trial versions. As such, the user, challenger, or inviter may monitor the status of the invitations/challenge. The one or more records may be published to an online service website such as a website, a social networking website, a website dedicated to users of software applications such as, for example, a game website, a blog website, a dating website, a web feed, a widget, or the like, using a browser, a dedicated application, service, or the like, which the users may access. The user, invitee/challengee, or inviter/challenger may monitor what invitations/challenges have been sent, received, and/or opened. The user, challenger, or inviter may also monitor which invitations/challenges have been presented and what was the response. The user, challengee, invitee, challenger, or inviter may further determine which one or more invitations/challenges or responses have been forwarded to additional users. The additional users may be contacts of the user, invitee/challengee, or inviter/challenger (e.g. members of the phonebook, social network website contacts, and fellow users of the applications and/or the like).
[0061] The invitee/challenge may receive an invitation from the user, challenger, or inviter without knowing the identity of the user, challenger, or inviter, in other words, the identity of the user, challenger, or inviter may not be initially revealed to the invitee/challengee, or vice versa, or other suitable combinations and variations. The invitation/challenge may include a message, from the user, challenger, or invitee or a default message, challenging the invitee/challengee. The anonymous nature of the invitation/challenge may spark the curiosity of the invitee/challengee. In some embodiments, the invitation/challenge may be authenticated by the user platform of the invitee/challengee to verify that the invitation/challenge is from a trusted source. As such, an authentication means, similar to the one described above, may identify that the inviter/challenger is a member of invitee's or challengee's user contacts (phonebook contact, contact stored remotely on server, or social networking website contact, and/or the like) by analyzing the user, challenger, or inviter's information that may be embedded in the invitation/challenge, although not revealed to appeal to the curiosity of the invitee. For example, a note indicating “You know this person” may be presented after verifying the identity of the inviter/challenger. For example, if the authentication means identifies the inviter/challenger to be a member of the invitee's or challengee's user contacts (phonebook contact, contact stored remotely on server, or website (e.g. social networking website) contact and/or the like, the invitee/challengee may be shown or otherwise notified (e.g. by vibrating the user platform, showing a note, playing a sound, and/or the like or a combination thereof) that “You have been challenged to a quiz game. You know the person who has challenged you. Do you dare to find out who he or she is?” Alternatively, if the invitation/challenge is sent by a contact not previously known to the invitee/challengee, the notification may indicate, for example, “An anonymous person has sent you a proposal. To find out who he or she is, complete the challenge!” Nevertheless, the invitation/challenge may have been authenticated by the user platform of the invitee/challengee to verify that the invitation/challenge is from a trusted source. After the invitation/challenge has been authenticated, the invitee/challengee may open the invitation/challenge, access the trial version of the application, and execute the application. The invitee/challengee may be allowed to execute the application and attempt to accomplish a response or meet the criteria of a challenge/invitation a predetermined number of times. The invitee/challengee may accomplish a response or meet the criteria of the invitation/challenge defined by the inviter/challenger. As such, the identity of the inviter/challenger and/or the hidden message may be revealed to the invitee/challengee. The invitee/challengee may receive a request to send one or more invitations/challenges to contacts of the invitee/challengee and undergo the same process as described above. In some embodiments, the invitation/challenge generator 234 may be configured to determine whether the invitee/challengee has already received the particular free trial version being sent or any trial version of the software application and as such may prevent the user from receiving the same trial version multiple times.
[0062] Referring to FIG. 4 , a method 400 of the present invention may include a Step 410 of determining the location of users. Step 420 may comprise assigning identifying information to the located user. Another step, Step 430 may include communicating with a computer server to store the user location and assigned identifying information. A Step 440 may involve retrieving a list from a computer of other users at the same approximate location of the located user. Assigning identifying information from the other users to the located user comprises Step 450 . Step 450 may also comprise assigning identifying information to other users or other configurations of exchanging information between users. A Step 460 may include transmitting the identifying information of the other users to the located user. Step 470 may involve filtering the transmitted identifying information according to attributes selected by the located user. Another step, Step 480 comprises initiating an electronic conversation between the located user and at least one of the other users selected by the located user. Yet another Step 490 comprises providing a response to an option to ignore, respond to, or block contact with one or more of the other users.
[0063] Another method 500 is shown in the flowchart of FIG. 5 . Step 510 comprises receiving an invitation from an inviter to execute at least a part of a software application. Another Step 520 may comprise executing at least part of a software application. Yet another Step 530 may include revealing an identifying characteristic of the challenger/inviter to an invitee/challengee. An additional Step 540 may involve receiving a request to prepare an invitation to an additional invitee/challengee. Step 550 may comprise preparing the invitation to the additional invitee/challengee. A Step 560 may include submitting a request to transmit the invitation to the additional invitee/challengee.
[0064] In FIG. 6 , another method 600 according to the present invention is displayed. A Step 610 may comprise receiving notification of an invitation via a software application. Another Step 620 may involve preparing an invitation. Yet another step, Step 630 may include transmitting the invitation/challenge to an invitee/challengee to allow the invitee/challengee to access at least a portion of the software application. A Step 640 may comprise revealing an identifying characteristic of the inviter/challenger to an invitee/challengee.
[0065] It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. Furthermore, a method herein described may be performed in one or more sequences other than the sequence presented expressly herein. As another example, any reference to an invitation may be considered to be a reference to a challenge. Any reference to an inviter may be considered to be a reference to a challenger. Also, any reference to an invitee may be considered to also be a reference to a challengee.
|
The present invention provides a method using one or more computers when conducting screened communications. The invention may comprise locating a first user and allowing other users to access the first user's personal attributes while allowing the first user to access the personal attributes of the other users. The users may filter potential communication participants based on each user's preferences and relative rankings regarding personal attributes of other users. More than one communication levels, with different communication formats, may be provided for a user to communicate with other users. A user may use the system to locate a particular type of person and/or venues with specific attributes. A user may use the system anonymously or with a pseudonym. Users may communicate at a particular location with or without observing another user at the particular location or at a different location.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent Application No. 10-2007-0059323 filed with the Korean Intellectual Property Office on Jun. 18, 2007, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a printed circuit board and to a method of manufacturing the printed circuit board.
[0004] 2. Description of the Related Art
[0005] Among the various methods for manufacturing a printed circuit board, one method currently being used to manufacture a high-density printed circuit board is illustrated in FIGS. 1A to 1H , which includes forming bumps 3 on a board 2 , stacking on an insulation layer 4 , and stacking this in turn onto a multi-layer board 1 , etc., while applying heat and pressure. This is referred to as a B2it method. With the B2it method, vias for interlayer conduction can be formed in a simple manner, whereby manufacturing efficiency can be increased.
[0006] The B2it method includes forming paste bumps, using copper (Cu), silver (Ag), etc., on a copper foil, piling an insulation layer with the copper foil, and then applying heat and pressure for stacking. In the B2it method, the process of printing the paste has to be performed such that the bumps have a height sufficient to penetrate the insulation layer. Thus, as illustrated in FIGS. 2A and 2B , the conductive paste 3 a, 3 b may be printed on the lands 9 formed on an insulation layer 4 ′ over a series of four or five repetitions. As such, the repeated printing intended for forming the bumps to a particular height can lower productivity, and can cause spreading at the lower ends of the bumps.
SUMMARY
[0007] An aspect of the invention is to provide a printed circuit board and a method of manufacturing the printed circuit board, which improve productivity and resolve the problem of spreading.
[0008] One aspect of the invention provides a method of manufacturing a printed circuit board by forming at least one bump for interlayer conduction on a surface of a board and stacking an insulation layer on the surface of the board. The method includes forming at least one dam on the surface of the board that surrounds a region corresponding to the bump, forming the bump by printing conductive paste onto the region corresponding to the bump, and stacking the insulation layer onto the surface of the board.
[0009] Forming the dam can be performed by selectively etching a metal layer stacked on the surface of the board, and the dam can be made of a material including copper.
[0010] Another aspect of the invention provides a printed circuit board that includes a board, a bump formed on a surface of the board, a dam formed on the surface of the board that surrounds an edge of the bump, and a first insulation layer stacked on the surface of the board.
[0011] The board can be a copper clad laminate (CCL), which has a copper foil stacked on a second insulation layer, in which case the dam may be shaped by selectively removing the copper foil.
[0012] Additional aspects and advantages of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1A , FIG. 1B , FIG. 1C , FIG. 1D , FIG. 1E , FIG. 1F , FIG. 1G , and FIG. 1H are cross-sectional views representing a flow diagram for a method of manufacturing a printed circuit board according to the related art.
[0014] FIG. 2A and FIG. 2B are cross-sectional views representing a flow diagram for a method of forming bumps according to the related art.
[0015] FIG. 3 is a flowchart illustrating a method of manufacturing a printed circuit board according to an aspect of the invention.
[0016] FIG. 4A , FIG. 4B , FIG. 4C , FIG. 4D , FIG. 4E , FIG. 4F , FIG. 4G , and FIG. 4H are cross-sectional views representing a flow diagram for the method illustrated in FIG. 3 .
[0017] FIG. 5 is a plan view illustrating a board on which dams have been formed.
[0018] FIG. 6A and FIG. 6B are cross-sectional views representing a flow diagram for a method of forming bumps.
[0019] FIG. 7 is a cross-sectional view of a printed circuit board according to another aspect of the invention.
DETAILED DESCRIPTION
[0020] The printed circuit board and method of manufacturing the printed circuit board according to certain embodiments of the invention will be described below in more detail with reference to the accompanying drawings. Those components that are the same or are in correspondence are rendered the same reference numeral regardless of the figure number, and redundant explanations are omitted.
[0021] First, the method of manufacturing a printed circuit board according to one aspect of the invention will be described as follows.
[0022] FIG. 3 is a flowchart illustrating a method of manufacturing a printed circuit board according to an aspect of the invention, and FIG. 4A through FIG. 4H are cross-sectional views representing a flow diagram for the method illustrated in FIG. 3 . In FIGS. 4A to 4H are illustrated a four-layer board 10 , insulation layers 20 a, 20 b, patterns 22 a, 22 b, dams 24 , bumps 30 , and bump boards 40 .
[0023] First, dams 24 may be formed, which surround regions corresponding to bumps 30 , on a surface of a board (S 10 ). The board may provide the position where the bumps 30 are to be formed, and in this particular embodiment, an insulation layer 20 a can be used for the board. Of course, the board can take a form other than an insulation layer 20 a. For example, a double-sided printed circuit board can be used that already has particular patterns formed on either side.
[0024] The insulation layer 20 a may serve to electrically insulate the upper and lower layers of the printed circuit board. A particular pattern may be formed on the lower surface of the insulation layer 20 a, and may even have several layers of boards stacked thereon.
[0025] A dam 24 can serve to confine the region of a bump that interconnects layers, as well as to provide support for the bump 30 . A method of forming the dams 24 will be described in more detail as follows.
[0026] First, an etching resist (not shown) may be formed on a metal layer (not shown) stacked on a surface of the insulation layer 20 a (S 11 ). The etching resist (not shown) can be formed to cover the metal layer (not shown) in positions where the dams 24 are to be formed. This etching resist (not shown) can be formed using a mask, by a method of exposure and development, etc. A copper clad laminate (CCL), which has a copper foil stacked on either side of an insulating layer, can be used for the insulation layer 20 a and the metal layer (not shown) stacked on the insulation layers 20 a.
[0027] Next, an etchant may be provided (S 12 ). Using an etchant, the portions other than those portions covered by the etching resist (not shown) can be removed. Afterwards, the etching resist (not shown) may be removed (S 13 ).
[0028] In cases where the dams 24 are formed by the method described above, the dams 24 can be formed simultaneously during the process for forming the patterns 22 a, etc., on the insulation layer 20 a. As such, since there is no need for a separate process in forming the dams 24 , the manufacturing process can be simplified. An example of the patterns 22 a and dams 24 formed on the insulation layer 20 a is illustrated in FIG. 4B and FIG. 5 .
[0029] After thus forming the dams 24 , conductive paste may be printed to form the bumps 30 (S 20 ). As illustrated in FIGS. 6A and 6B , the regions where the conductive paste 30 a, 30 b are printed may be surrounded by the dams 24 . Therefore, during the procedure for forming the bumps 30 by printing the conductive paste 30 a, 30 b, the lower ends of the bumps 30 may be supported by the dams 24 , and the areas of the board occupied by the bumps 30 can be limited by the dams 24 . In this way, the lower ends of the bumps 30 can be prevented from spreading to a wider area than that intended. Also, compared to those cases in which dams 24 are not formed, relatively larger amounts of conductive paste 30 a, 30 b can be printed in one round.
[0030] Therefore, the number of repetitions of printing for forming the bumps 30 to a particular height can be reduced, to confer an aspect of increased productivity. The results of repeatedly printing the conductive paste 30 a, 30 b are illustrated in FIGS. 6A and 6B , and the bumps 30 thus formed can be seen also in FIG. 4C .
[0031] Next, an insulation layer may be stacked on to form a bump board (S 30 ). The insulation layer 20 b can be stacked over the insulation layer 20 a on which the bumps 30 and the pattern 22 a are formed, where the bumps 30 can be made to penetrate the insulation layer 20 b. The insulation layer 20 b may serve to provide electrical insulation between layers, and can be made, for example, from Prepreg.
[0032] Bump boards 40 formed as above may be stacked onto a four-layer board 10 , as illustrated in FIG. 4E , to implement a multi-layer printed circuit board such as that illustrated in FIG. 4F .
[0033] Afterwards, holes 26 can be perforated in the outermost layers, as illustrated in FIG. 4G , and interlayer conduction can be provided at the outermost layers using a method such as forming plating layers 28 in the holes 26 .
[0034] An example of a printed circuit board manufactured by the method described above is illustrated in FIG. 7 . FIG. 7 is a cross-sectional view of a printed circuit board according to another aspect of the invention. In FIG. 7 are illustrated a four-layer board 10 , insulation layers 20 a, 20 b, patterns 22 a, 22 b, dams 24 , bumps 30 , and bump boards 40 .
[0035] In the case of the printed circuit board according to this embodiment, conduction between layers can be implemented by elements including the bumps 30 which penetrate the insulation layers, and the plating layers which are formed in the holes 26 . A dam 24 can be formed around the edge of a bump 30 to surround the bump 30 , where such dams 24 may facilitate the forming of the bumps 30 while preventing spreading.
[0036] The insulation layers 20 a, on which the dams 24 are formed, and the patterns 22 a, 22 b formed on these insulation layers 20 a can be formed by selectively removing the copper foils of a copper clad laminate, where the dams 24 can be formed by the same method, as already described above.
[0037] According to certain embodiments of the invention as set forth above, by forming dams and printing the bumps for interlayer conduction inside the dams, productivity can be improved and the problem of spreading can be resolved.
[0038] While the spirit of the invention has been described in detail with reference to particular embodiments, the embodiments are for illustrative purposes only and do not limit the invention. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the invention.
|
A printed circuit board and a method of manufacturing the printed circuit board are disclosed. The method of manufacturing a printed circuit board, by forming at least one bump for interlayer conduction on a surface of a board and stacking an insulation layer on the surface of the board, can include the operations of forming at least one dam on the surface of the board that surrounds a region corresponding to the bump, forming the bump by printing conductive paste onto the region corresponding to the bump, and stacking the insulation layer onto the surface of the board. This method can be utilized to improve productivity and resolve the problem of spreading.
| 7
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to filters, and more particularly to a filter housing which accepts plural replaceable filter elements to be contained within a single housing. The filter elements are disposed in series for filtering purposes. The housing accommodates flushing without requiring removal of the filter elements.
2. Description of the Prior Art
In light of many contaminants which may become entrained in water supplied by domestic plumbing systems, it is desirable to filter the water prior to employing the same for human consumption. Many filters are commercial products featuring filter cartridges which are readily installed and serviced by residential occupants who may lack specialized skills of a plumber. These filters conventionally comprise housings which enclose one or more filtering elements. Consequently, separate replaceable filtering elements are readily available from commercial sources.
A filter seen in U.S. Pat. No. 3,780,869, issued to Zaharias Krongos on Dec. 25, 1973, has a housing formed in two threadably mating parts, which housing encloses plural replaceable filter elements. The filter of Krongos lacks the flushing circuitry, serial filtration circuitry, and inlet and outlet arrangement of the present invention.
U.S. Pat. No. 30,366, issued to M. W. Warne on Oct. 9, 1860, shows a vessel having plural compartments each containing filtration material and connected in series. The device of Warne lacks the flushing circuitry, inlet and outlet arrangement of the present invention, readily replaceable filter cartridges capable of holding their form without supporting, surrounding walls, and adjustable compression of such filter cartridges, all being features of the present invention.
U.S. Pat. No. 136,364, issued to Walter M. Conger on Mar. 4, 1873, illustrates a filter having filter elements disposed in series and also flushing circuitry. However, the device of Conger lacks the threaded, separable, two part housing of the present invention, flushing circuitry contained within a part of the housing, adjustable compression of filter cartridges elements, and the inlet and outlet arrangement, and internal flow scheme of the present invention.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
The present invention provides a readily installed and serviced filter apparatus which employs readily available filter cartridges and which further enables ready flushing. The novel filter apparatus includes a threaded, two part housing which can be opened to expose the plural filter cartridges without interrupting liquid connections. The housing includes an inner canister which is adjustably compressed by a bolt accessible from the exterior of the filter, to secure filter cartridges by compression. The filter has one threaded inlet and two threaded outlets, one outlet for filtered water and the other to discharge waste when flushing.
The filter apparatus accepts a plurality of filter cartridges. Internal liquid flow circuitry passes water serially through the several cartridges. This ability may be exploited to subject all water to filters designed to trap different contaminants. The filter can be flushed automatically or with minimal difficulty, in particular requiring neither removal of the filter cartridges nor disassembly from the domestic plumbing system. The filter is configured to assure that water employed for flushing will not be discharged in common with filtered water.
Accordingly, it is one object of the invention to provide a water filter readily connectable to a domestic plumbing system.
It is another object of the invention to provide a water filter which accepts plural filter elements.
It is a further object of the invention that the filter employ commercially available filter cartridges.
Still another object of the invention is to enable flushing without requiring removal of filter elements.
Yet another object of the invention is to prevent water employed to flush the filter to be discharged in common with filtered water.
An additional object of the invention is to provide a filter housing which opens to expose filter elements without requiring disassembly from the domestic plumbing system.
It is again an object of the invention to enable compression of the housing to secure filter cartridges.
Yet another object of the invention is to provide serial flow through plural filter cartridges.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
FIG. 1 is an exploded, perspective view of the invention.
FIG. 2 is an environmental, side elevational view of the invention, with some environmental components shown diagrammatically.
FIG. 3 is an exaggerated, diagrammatic representation of fluid circuitry of liquid being filtered.
FIG. 4 is a modified plan view of the invention showing only passages introducing liquids for filtering, transferring liquids between adjacent filtering chambers, and discharging filtered liquid.
FIG. 5 is a cross sectional view of the invention.
FIG. 6 is an isometric, diagrammatic representation of flushing circuitry.
FIG. 7 is a modified top plan view of the top of the novel filter housing, wherein arrows indicate flow during flushing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to FIG. 1 of the drawings, novel multi-element filter housing 10 is seen to comprise a cap 12 having an inlet 14, a first outlet 16 for discharging flushing liquid, and a second outlet 18 for discharging filtered liquid. A canister 20 divided into four separated chambers 22 by four internal walls 24 contains one filter cartridge 26 in each chamber 22. Filter cartridges 26 are annular, open at the top and at the bottom, and are conventional, commercially available products. Filter cartridges 26 may differ in their filtration characteristics despite similar dimensions and configuration. Canister 20 has a solid or continuous bottom 28, a peripheral wall 30, and an open top 32. Bottom 28 and wall 30 are continuous, so as to retain liquid within canister 20. Circumferential grooves (see FIG. 5) formed towards the top and bottom of canister 20 are provided to seat O-rings 34.
A retainer 36 holds canister 20 against the bottom surface 38 of cap 12 when secured to cap 12. Retainer 36 has male threads 40 which mate with female threads 42 formed in cap 12. Threading retainer 36 to cap 12 squeezes or pins canister 20 against cap 12. Canister 20 is dimensioned and configured such that both canister 20 and filter cartridges 26 come to abut cap 12 simultaneously when canister 20 is threaded to cap 12. Vertically disposed pick up tubes 44, the purpose of which will be explained hereinafter, depend from bottom surface 38 of cap 12, and are configured and located to project into chambers 22 without interfering with filter cartridges 26. Pick up tubes 44 each are dimensioned and configured to terminate proximate bottom 28 of canister 20 when canister 20 abuts cap 12. Each pick up tube 44 is also configured and located to project into its one corresponding chamber 22 of canister 20.
Position of canister 20 relative to cap 12 is critical to alignment of fluid conduits. Consequently, canister 20 may not rotate about axis 46. Nub 48, which also serves to align canister 20 concentrically with respect to cap 12, is configured other than circular in cross section, so that it acts as a keying element constraining canister 20 and cap 12 against mutual rotation. Nub 48 fits into a correspondingly configured recess 50 (see FIG. 5) formed in cap 12.
Retainer 36 has a continuous annular wall 52 and a continuous floor 54, and thus surrounds and seals canister 20 between cap 12 and retainer 36 when retainer 36 is tightened and fully engages cap 12.
FIG. 2 depicts filter housing 10 as it would be installed in a domestic plumbing system. Direction of flow of water is indicated by arrows. Incoming water flows in the direction of arrow 56. Filtered water is discharged from outlet 18 in a direction indicated by arrow 58. Flushing employs water from inlet 14, but keeps flushing water separated from filtered water. Flushing water is discharged from outlet 18 as indicated by arrow 60. Inlet 14 is connected to a supply of pressurized water, as represented by conduit 2. Outlet 18 is connected to a pipe or conduit 4 supplying spigots (not shown) and water utilizing appliances (not shown). Outlet 16 is connected to a pipe or conduit 6 arranged to discharge flushing water to a suitable drain (not shown) or other facility for disposal. Conduit 6 is controlled by a solenoid valve 7 which is, in turn, controlled by a suitable control is device 8. Control device 8 may be a time clock, a manual switch, or any other device enabling manual or automatic operation of solenoid valve 7.
Liquid flow through filter housing 10 is shown in simplified, diagrammatic manner in FIG. 3. Unfiltered water obtained from the domestic water supply enters one chamber 22 (see FIG. 1) from cap 12, as indicated by arrow 62. It will be recalled from FIG. 1 that chambers 22 are separated from one another by walls 24. A port 64 (see FIG. 5) admitting water is arranged to discharge this water outside the open center of the filter cartridge 26 occupying the chamber 22 receiving water. As this chamber 22 fills, pressure will urge water through the filtering element of cartridge 26 into the open center. Filtered water descends to a passage formed in the bottom of canister 20. This passage conducts water to a second chamber 22, as indicated by arrow 66. Water enters the second chamber 22 outside the open center of the second filter cartridge 26. As the second chamber 22 fills, water passes through the filtering element of the second filter cartridge 26 into the open center.
Another passage conducts water to a third chamber 22, as indicated by arrow 68, where the process of filtration and passage of water to the open center of a filter cartridge is again repeated. Water passes as shown by arrow 70 to the fourth chamber where it is once more filtered under influence of fluid pressure. However, the bottom 28 (see FIG. 1) of canister 20 is closed beneath the fourth filter cartridge 26. A passage formed in cap 12 is open to the center of the fourth filter cartridge 26, and filtered water passes to outlet 18 (see FIG. 4) through this passage, as indicated by arrow 72. In summary, filter housing 10 conducts liquid serially through the various filter elements or cartridges 26 contained within filter housing 10. Water is thereby subjected to the cumulative effect of all four filters. This may result in highly efficient or thorough filtration, if all filter cartridges 26 are of similar filtration characteristics. Alternatively, filter cartridges 26 may have different filtration characteristics. Illustratively, different contaminants could be trapped by different filter cartridges 26. Use of four different filter cartridges could be exploited to eliminate many different contaminants which could be present in unfiltered water passing through the domestic plumbing system.
Passages formed in bottom 28 of canister 20 are illustrated in the plan view of FIG. 4. Water discharged from port 64 fills chamber 22A and open center 74 of filter cartridge 26A. This water is conducted by a canister internal passage 76 to chamber 22B. Water will fill open center 78 of filter cartridge 26B, then pass through a canister internal passage 80 to chamber 22C. Water will finally pass through a canister internal passage 82 to chamber 22D. Thus passages 76, 80, 82 each communicates between adjacent chambers 22A, 22B, 22C, 22D, transferring liquid in serial fashion from one chamber 22A, 22B, or 22C to subsequent chambers 22B, 22C, 22D. Water leaves chamber 22D through a port 94 of outlet 18.
Certain components of novel filter housing 10 have been omitted for clarity in the view of FIG. 4. FIG. 5 shows the components omitted from FIG. 4. Walls 24 and filter cartridges 26 are omitted from FIG. 5 for clarity. Pick up tubes 44 are seen to depend from bottom surface 38, there being one pick up tube 44 for each chamber 22 (see FIG. 1) of canister 20. FIG. 5 also shows internal passages formed in cap 12 and in bottom 28 of canister 20. A first cap internal passage 86 conducts incoming water into the first chamber 22A (see FIG. 4). A second cap internal passage 88 comprises a portion of the flushing circuit. A third cap internal passage 90 conducts filtered water to outlet 18. Passages 86, 88, 90 all extend from bottom surface 38 of cap 12 to their respective inlet 14, outlet 16, and outlet 18.
Thus far, the filtering circuit has been described. The filtering circuit includes first cap internal passage 86, passages 76, 80, and 82 located in bottom 28 of canister 20, and third cap internal passage 90. The flushing circuit also utilizes first cap internal passage 86 for supplying flushing water, and passages 76, 80, and 82 to transfer water sequentially to each chamber 22. Water discharged from each chamber 22, rather than being collected in third cap internal passage 90 for disposal, is instead collected in second cap internal passage 88. Water and contaminants pass upwardly through pick up tubes 44, which communicate in parallel with passage 90. Water and contaminants are finally discharged through outlet 16 without coming into contact with and subsequently fouling third cap internal passage 88.
The flushing circuit, although not all components of filter housing 10, is shown diagrammatically in its entirety in FIG. 6. Direction of flow is indicated by arrows (unnumbered in the view of FIG. 6). The view of FIG. 6 clearly shows collection of liquid from each chamber 22 (see FIG. 1) at the bottom of pick up tubes 44. It should be stressed at this point that nub 48 (see FIG. 1) is keyed to assure that first cap internal passage 86 is disposed in vertical registry and fluid communication with one chamber 22 (see FIG. 1) and third cap internal passage 90 is disposed in vertical registry and fluid communication with another chamber 22 when cap 12 is secured to canister 20. In particular, that chamber 22 not provided with a canister internal passage 76, 80, or 82 opening to the chamber 22 outside its respective filter cartridge 26 is disposed in vertical registry with port 64 of cap internal passage 86. Similarly, that chamber 22 not provided with a cap internal passage 76, 80, or 82 opening to the chamber 22 at the open center of its respective filter cartridge 26 is disposed in vertical registry with port 94 (see FIG. 4) of cap internal passage 90.
FIG. 7 shows a representative configuration of cap 12 as it relates to first, second, and third cap internal passages 86, 88, 90. Flow of the flushing circuit is shown in arrows (unnumbered in the view of FIG. 7).
Returning to FIG. 5, seating and concentric alignment of canister 20 within retainer 36 is assured by a shoulder 92, and by cooperation between nub 48 and recess 50.
FIG. 5 also shows a tightening member assuring tight abutment of individual filter cartridges 26 (see FIG. 1) against the bottom surface 38 of cap 12. A bolt 96 threads into floor 54 of retainer 36. When retainer is fully threaded against cap 12, turning bolt 96 so that it progressively and adjustably moves upwardly (towards cap 12 in the depiction of FIG. 5) will cause bolt 96 to bear against a piston 98. Piston 98 will then urge canister 12 against cap 20 responsive to this adjustment. Piston 98 is a protective member or plate slidably disposed within retainer 36 which transmits force from bolt 96 against canister 20 without allowing bolt 96 to damage canister 20. A spin plate 100 which fits against surface 38 of cap 12 provides a measure of resilience and a surface having suitable low friction characteristics to seat and seal the upper surfaces of filter cartridges 26, canister 20, and retainer 36 when tightening retainer 36 to cap 12. Spin plate 100 comprises three members, there being top and bottom layers of nylon and a center layer of metal.
The present invention is susceptible to variations and modifications which may be introduced without departing from the inventive concept. Several examples of modifications will be set forth. Filter housing 10 may be provided with any number of chambers 22 and appropriate fluid circuitry to accommodate any number of filter cartridges 26. Inlet 14 and outlets 16, 18 may be formed as female members within cap 12 rather than the male members depicted. Threads 40 and 42 joining retainer 36 to cap 12 could be replaced by screws (not shown), latching arms (not shown), or other fastening elements which could serve in their place.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
|
A filter housing assuring serial filtration of a liquid through plural filter cartridges and enabling flushing without requiring removal of the filter cartridges. The filter housing has a cap including a liquid inlet, a filtered liquid outlet, a flush liquid outlet, and internal passages. The filter cartridges are held within a canister which is pressed against the cap and constrained against rotation with the cap. A retaining member surrounding and bearing against the canister threads to the cap. The canister is divided into chambers, and has passages in its floor arranged to enable serial transfer of liquid from one chamber to the next. Flushing employs liquid introduced under normal pressure. Passages leading to the flush liquid outlet enable flushing to proceed when the flush liquid outlet is opened. At other times, filtered liquid will pass through passages leading to the filtered liquid outlet. Liquid is circulated to assure filtration even when flushing, so that contamination of filtered liquid is precluded.
| 1
|
Microfiche Appendix of Computer Program Listing is filed herewith, 2 Microfiches; 84Frames.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to the analysis of metal failure, and specifically to combining automated visual aids with an expert system having a knowledge base of metal failure.
2. Background of the Invention
For many years the problems associated with metal failure in the industrial environment have been researched and documented. This knowledge is extensive and is mainly in the hands of metallurgical experts. The costs of repairing components due to metal failures is high. Expert systems have been employed in industrial plants, service companies, and medical institutions to diagnose problems or illnesses. Expert systems have not been used in conjunction with visual displays for metal failure analysis.
Metal failures are analyzed using metallurgical expertise and techniques. These metal failures may occur in components such as pumps, valves, turbine blades, gears, shafts, drives, and virtually any other mechanical structural or aerospace metallic component. Normally sections of pieces of the damaged component are sent to a metallurgist outside the plant site where the failure occurred. The metallurgist may be form an independent consulting firm or may be employed by the company where the failure occurred if the expense of a full-time expert can be justified. Even if a company has a full-time metallurgist, the metallurgist may be far from the emergency at hand, working out of a distant home office. Since metal analysis must be performed by the metallurgist in person, a great deal of time and expense are wasted either by shipping failed parts to the metallurgist or by transporting the expert to the failure site.
Normally these metal failure experts rely on private knowledge and past experiences to analyze the failed component rather than just chemical or physical evaluation procedures. These "intuitive" and knowledge based techniques are often performed in an apparently unsystematic fashion. This apparently unsystematic procedure is comparable to the question and answer routines physicians use in diagnosing a patient's illness. An "If-Then" type logic precedes actual physical or biological tests and can often be used to determine the exact cause of the problem or illness, and is used conjunction with a visual examination. Subsequent testing is used for verification.
First, the metallurgist asks the maintenance staff questions pertaining to the material, locations, and environment where the failure is concerned. Visual inspections may be performed. In metallurgical failure analysis, the appearance can often indicate the cause of a problem with a component, but this information has been unavailable until now to the personnel who routinely repair, replace, or inspect the component in question. From the appearance of the failed component the failure mechanisms can often be determined, or it may be determined that further testing is needed. Often these tests are performed as a means of verifying the mechanism before the root-cause is confirmed by the metallurgist. The tests may be non-destructive-evaluations(ultrasonic, radiography, computer tomography, etc.); chemical tests(hydrogen, embrittlement, erosion/corrosion analysis; etc.) or physical tests(stress tests, fatigue testing, hardness testing, etc.). This process has not been well systematized for non-experts by the prior art because of lack of visual display providing correlation between observations and relevant conditions for isolating failure mechanisms.
Another object is to provide an expert system with relevant exemplary video displays correlated to both information gathering and solution presentation modes.
A further principal object of the present invention is to be able to use a visually aided expert system as an inanimate metallurgical consultant for determining the failure mechanisms and root-causes of the metal failure and deterioration.
Another important object is to provide an expert system for trouble-shooting metal failures which provides the equivalent of the human expertise employed by the metallurgical specialist, whose expertise would not be lot due to retirement, promotion, death or transfer.
Another paramount object of the invention is to provide visual aids depicting both a macroscopic and microscopic appearance of metal failure that are coordinated for display by an expert system program and which can be used by an operator in the system to find a failure mechanism and to conduct root cause analysis.
It is an object of the invention to provide a knowledge base housed in an expert system which would be constantly upgraded at appropriate intervals. A further paramount object of the invention is to assure that the knowledge contained in an expert system is easily transferable and can be applied at many different locations simultaneously.
It is also an object of the invention to provide an expert system for use in metal failure analysis which can provide immediate solutions whereby valuable time is conserved and corrective actions are implemented quickly at a time when obtaining this information is essential.
SUMMARY OF THE INVENTION
I have invented a system and method for metal failure analysis using a visually aided computer based expert system. It can be used to analyze metal failures in aircraft, industrial equipment, metal structures, nonindustrial equipment, and similar applications. It is an expert system that uses rule-based investigative procedures. An if-then based logic course is followed by the rules incorporated in the knowledge base. Thus, it creates a understandable systematic approach in determining the failure mechanism that can be used by non-expert as opposed to the normal, apparently non-systematic, intuitive course followed by human experts.
Through automated visuals emanating from a slide viewer/projector or other pictographic or photographic apparatus, the system uses pictures of failed metal components in identifying the failure mechanism. By showing an individual what to look for it assists the individual in arriving at a decision of information to be supplied to the expert system. The appearance of a component can be accurate indicator of metallurgical properties of the component. Only after determining or analyzing the macroscopic or microscopic appearance does the expert system or its human expert counterpart suggest further specific testing to determine or verify the failure mechanism.
Repeat failures in all types of metal components often are similar in appearance and can be represented on color or black and white transparencies, video displays or other photographic or pictographic means. An expert system program can be effectively structured on rules based on failed metal appearance, among other factors. Overall, in all areas of metal failures these can number in the thousands, but when broken down by specific components and failure mechanisms the different guises are few and are systematically manageable when combined with he rule-based investigative procedures employed by the expert system. By coupling these logically sequenced visual images with an expert system a unique tool has been created to aid the non-expert in determining the failure mechanisms in failed metal components, using information as to appearance, location, environment, preceding history or events and so on. It can also be used for training purposes. The system and method also incorporates a data base to provide statistical data to plan inspections, update the rules of the knowledge base, or to generate reports detailing a failure incident.
The system can be operated on a micro computer or other data processing system and includes both expert system and database software. These are linked by an interface card to a computer controlled visual display, such as a slide projector, video disk, or video tape.
Graphics displayed on the computer's monitor interact with the various data base sections. Detailed diagrams of the equipment components in question are displayed on the monitor and specific areas of each can be examined closely. The specific parts have their own records which can be pulled up for updating and review. Actual photographs of the various parts can also be displayed on the visual display. The different examples of metal failures can also be reviewed in this fashion.
Besides the expert system(diagnostic)and database modules, the system also contains an information retrieval module. This module contains additional information on nondestructive evaluation (NDE) methods, welding procedures, root-cause analysis, metallurgical testing, corrective actions, references to other sources of information and similar information.
Once the expert system(diagnostic module)has determined the failure mechanism, a root-cause is projected. If the expert system is unable to determine the failure mechanism due to a lack of data if can still project probable mechanisms using the data it has already obtained. In some instances further information, such as the results of metallurgical tests, is needed by the program to determine the failure mechanism and root-cause. If this is the case, the program will ask for a direct the user to the information it needs.
It is an object of the present invention to provide a micro-computer based expert system for metal failure analysis having an video or photographic display.
These and other objects of the present invention will be apparent from the detailed description, taken with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a system for a micro-computer based metal failure analysis expert system with visual display according to the invention;
FIG. 2 is a hierarchical diagram of systems and record files;
FIG. 3 is a flow chart for the expert system subsystem, including access to the visual display;
FIG. 4 is a hierarchical diagram of the data base subsystem; and
FIG. 5 is a hierarchical diagram of the information retrieval subsystem.
DETAILED DESCRIPTION
Reference is now made to the figures wherein like numbers refer to like parts throughout. FIG. 1 discloses in block diagram a suitable micro computer structure for implementation of the present invention. A hardware system, generally designated 10 is provided which comprises a personal computer 12, an output device such as a cathode ray tube 14, an input device such as keyboard 16 and a visual display apparatus 18. The visual display apparatus 18 is connected to the personal computer by an interface 20. The visual display 18 is preferably a software controllable visual system. In the preferred embodiment, a software selectable slide system, such as a DUKANE PRO 120 system available from Dukane Corporation can be used. Of course, those skilled in the art will recognize that other visual devices could be used without departing from the spirit and teachings of the present invention. For example, a software controllable video disk might be used, particularly one that can receive new visual images from time to time.
The micro computer 12 comprises a user interface 22 which substantially interconnects the components of the hardware system 10. Associated with the personal computer 12 are various processing commands comprising the control functions of the system. These command structures are preferably implemented in software, but they may also be implemented by EPROMS(erasable programmable read only memory), or by other invariable data processing devices. The control systems comprise an expert system 24, a data base system 26 and an information retrieval system 28, all of which are completely described below. The micro computer 12 further comprises a memory device 2 for storing data.
The interrelationship between the various control systems can best be understood with reference to FIG. 2. The expert system 24 may be invoked to identify a failure mechanism from metal fatigue or otherwise in a system. Expert systems are known in the art. For example, a basic expert system tool is described in U.S. Pat. No. 4,648,044 to Hardy, et al. Using the expert system, a user will interact with the system by responding to queries presented by the expert system with information or selections. To aid the user in making selections, the knowledge base 27 is accessed by the expert system 24 as the inquiry proceeds. From time to time visual records 29 will also be accessed by the expert system to supplement requests for information or to allow the user to select from different visual possibilities to identify the type of a problem or failure. As the user and expert system interact, a record is created of the incident and the expert system 24 gathers data in the incident file 30. This data relates to the specific incident under investigation. The incident file 30 represents not only a record of the particular incident under investigation, but can also be used to accumulate historical and statistical data related to a particular industrial installation or plant. Through inquiry and response, the expert system will identify a likely candidate for a mode of failure related to a particular industrial incident, or it will recognize that insufficient data has been supplied and return a report indicating that no analysis can be made. If an analysis is made, the expert system should again direct the attention of the user to possible causes of the identified failure and to additional test which may be performed to isolate the failure mode in a root failure analysis 32.
The second control system provided is the data base system 26. This system is used primarily to access records of incidents previously stored through the expert system. However, the data base system can also be used to build its own records of incidents, even if a failure analysis is not performed. The data base system 26 provides the user with access to individual incident and to statistical compilations of numerous incidents. The user is assisted in understanding the incident by access to the visual records 29 which provide generalized visual displays of types of failure modes or parts. It will be noted that by using a high quality visual display, such as the photographic slide projecting visual display 18 mentioned above, a very clear understanding of the part or type of failure can be expected. The data base system 26 can also access the expert system 24 and the knowledge base 27 from time to time to perform subanalysis of particular incidents file.
The third control system is the information retrieval system 28. Using the information retrieval system 28, a user can access the knowledge base 27 and associated visual records 29 in the manner of a reference library. No information on a particular incident is required. Examples of parts, types of failure, or other information can be retrieved quickly and easily.
As pointed out above, both the expert system 24 and the data base system 26 can accumulate incident information in the incident file 30. From time to time the information in the incident file 30 is complied statistically to modify 32 the knowledge base 27. This enables the knowledge base 27 to be continually updated by ongoing accumulation of information.
Reference is now made to FIG. 3, wherein a flow chart for an expert system, including access to visual records is disclosed. The expert system 24 is invoked at a start command 34. In a conventional manner, the knowledge base 27 is accessed 36 to commence a user-computer interaction. As information is gathered from the user, an inference engine 38 selects among possible inquiry pathways. A typical inference engine is described in Hardy, U.S. Pat. No. 4,648,044, mentioned above. If the inference engine 38 concludes that the goal of the inquiry was reached 40, that is, that a possible failure mode has been identified, control of the program will be directed to the root failure analysis 32 more particularly described below. If the goal has not been reached 40, a further question will be presented 42 regarding location, material, event, operating history, appearance or other relevant factor. When a question has been isolated, it will be determined 44 if a picture or visual display is associated with the particular question. This may comprise either a single visual display or a series of visual displays which may be associated with a multiple part question. If a picture is found, a command is issued to the visual display 18 to display 46 the picture. A user response 48 to the question is then required. The system 24 will then check 50 for a valid response and either return control for re-entry of the response if the response was invalid, or, if the response was valid, branch to the inference engine 38. The loop is continued until it is determined that the inquiry has been successful and the goal has been reached 40.
When the goal has been reached 40, program control branches, in the preferred embodiment, to a root failure analysis 32. Inquiry 50 is made if the selected possible failure mode has a probable cause of failure. If it can not be determined that the root cause of failure has been reliably identified, an attempt to verify 54 the location and appearance of the failure will be made. The root failure analysis system 32 will check 56 to determine if there is visual data available associated with a particular possible failure mode. If visual data is available, it will be displayed 58 on the video display 18. A response is then requested 60 from the user to determine if the location and appearance is verified. If the user agrees that the visual appearance of the possible failure cause is sufficiently similar to the actual appearance of failed parts, data related to the failure cause is retrieved 62. This data may relate to suggested additional tests which may be performed to further isolate the root causes of a failure or may identify, for example, possible steps which may be taken to alleviate the causes of failure. If no additional data is found, a report 64 is made. If it is determined 52 that the identified possible root failure is indeed the most probable, appropriate recommendations for further testing for preventative or other measures will be made 66. When the root failure analysis 32 is substantially complete, the information gathered during the expert system operation 24 and the root failure analysis 32 will be stored 68 for information retrieval in the incident file 30. A program listing has been provided in a Microfiche Appendix, which is incorporated herein by reference.
Reference is now made to FIG. 4 wherein a functional diagram of the data base system 26 is disclosed. When the data base system is invoked 68 the user may choose to either correlate data 70 or to collect incident data 71. If data is to be correlated 70 the user may further choose to recall incident specific data 72 related to a particular incident which has previously been recorded. Statistical data 74 may be complied concerning a range of incidents already available and collected in the system. Different parameters may be selected for statistical analysis. Such factors may include specific plants, time periods, types of parts, types of failure or other types of information available to the system. If the user chooses to collect incident data 71, an abbreviated form is provided to accumulate data which might otherwise be collected through the expert system 24. At intervals during the data collection process, the user may choose to branch to the expert system to verify data 76. Through this means, the user will have access to the visual records 28 through the visual display 18 to compare 78 the visuals. This will permit the user to increase confidence level in the accuracy of information by comparing the expected information with the visual examples. A program listing has been provided in a Microfiche Appendix, which is incorporated herein by reference.
The third system is the information retrieval system 28. A functional block diagram of this system is disclosed in FIG. 5. When the information retrieval system is invoked 80, the user may choose to directly modify 82 the knowledge base or to merely access 84 the knowledge base as a computerized index. As information is retrieved, the associated visuals 86 will be recalled from the visual records 28 and displayed through the visual display 18. A program listing has been provided in a Microfiche Appendix, which is incorporated herein by reference.
Each of these systems, therefore, provide interactive access to the visual information contained in the visual records 28. It can be expected, therefore, that the systems can be used with substantial accuracy by persons with minimal expertise. Rapid access to visual information correlated with specific information seeking-questions will increase the reliability of the information gathered and of the resulting analysis. The invention may be embodied in other specific forms without departing from the spirit or teachings of the present invention. All embodiments, therefore, which come within the meaning and range of the doctrine equivalents are intended to be included herein and the scope of the invention should be determined by the appended claims, and not by the foregoing description.
|
Apparatus and a method for providing a micro-computer based expert system having a knowledge base of failure analysis, as it pertains to metallic components. The apparatus and method includes interactive initialization procedure which includes communications between the user and the knowledge base. The sytem and method incorporates automated visual aids for the analysis of metal failure.
| 8
|
BACKGROUND OF THE INVENTION
The invention relates generally to couplers for selectively interconnecting cranes and backhoes to various earth and material handling devices such as buckets, blades and claws and more specifically to a coupler which may be permanently attached to the crane boom or backhoe dipper stick which automatically attaches to and manually releases from a bucket, blade, claw or material handling attachment.
The broad utility of cranes and backhoes is apparent from the even broader array of attachments with which such devices are utilized. For example, buckets, grapples, blades, picks and hooks are all commonly used with cranes and backhoes. Furthermore, within the broad category of buckets are numerous styles and sizes intended for digging variously shaped trenches in diverse material or relocating materials, for example, from or to the ground or a dump truck.
With this versatility comes the attendant problem of interchanging such attachments on a given crane or backhoe. Given the specialization of attachments one particular attachment may only be utilized for a brief task and changing attachments becomes an ever present and time consuming problem.
The problem has not gone unaddressed. There exists a relatively extensive collection of devices having the purpose of permitting expeditious connection, use and release of one attachment and re-connection of another. Generally speaking, these devices can be segregated into two classes: those which require manual activation to connect and/or release an attachment and those which incorporate remotely controlled mechanisms which render the coupling and disconnection substantially automatic. Manually activated devices will be reviewed first.
U.S. Pat. No. 4,187,050 to Barbee teaches a quick disconnect coupling mechanism which includes a forward, curved member which opens to the rear and engages a forward crossbar on a bucket and a rear hook-like member which receives a rear bucket crossbar. The rear member pivots to a crossbar retaining position and is maintained there by a spring biased latch. U.S. Pat. No. 4,214,840 to Beales teaches a quick-release coupler having a pair of parallel crossbars which are received within correspondingly positioned, diversely oriented throats on a bucket which also includes a spring biased latch mechanism. A hydraulically operated latch mechanism is also disclosed.
In U.S. Pat. No. 4,297,074 to Ballinger, the bucket likewise includes a pair of parallel spaced-apart crossbars which are engaged by a coupling member having front throats and rear throats which are oriented at 90° to one another. A pivotable locking clevis disposed on the rear bucket crossbar secures the coupler to the bucket. In U.S. Pat. No. 4,436,477 to Lenertz et al.. a coupler includes similarly oriented front and rear throats as well as a pivoting hook which translates to engage and retain a rear bucket crossbar in the rear throat of the coupler.
U.S. Pat. No. 4,632,595 to Schaeff utilizes a bucket having a forward crossbar member and rear plate. The coupler includes forward opening throats which engage the front crossbar member and a spring biased latch at the rear which hooks on the underside of the plate. Attachment is automatic and release requires manual translation of the hook to overcome a biasing spring.
U.S. Pat. No. 4,810,162 to Foster teaches another variation on a coupler having an open forward throat which engages a forward crossbar in a bucket and a moving member at the rear which pivots and engages a rear crossbar. The frame of the coupler includes slots for receiving the rear crossbar and a pivoting member spaced between the walls of the coupler which engages the bucket crossbar and pivots to retain the crossbar in the rear coupler slots. In U.S. Pat. No. 4,854,813 to Degeeter et al., the bucket includes forward and rearward circular reentrant regions which receive complementarily configured and disposed transverse members on the boom. A sliding latch is manually positioned to retain the bucket boom components in the re-entrant regions of the bucket.
U.S. Pat. No. 4,955,779 presents another connector wherein the bucket includes opposed re-entrant channels and the coupler includes complementarily disposed members which engage the reentrant portions and secure the bucket to the boom. In U.S. Pat. No. 4,986,722 to Kaczmarczyk et al., a combination of the above features are found. At the front of the bucket, a circular cross member is utilized which is engaged by a transverse slot on the boom coupler. At the rear of the bucket are a pair of spaced apart slotted members which receive a transverse circular member disposed on the boom. A manually operable latch retains the rear transverse boom member in the slots of the bucket.
The second group of prior art patents includes remotely activatable coupling devices. U.S. Pat. No. 4,355,945 to Pilch teaches a coupling mechanism similar to that disclosed in U.S. Pat. No. 4,436,477. The bucket includes a pair of transversely disposed spaced-apart crossbars and the coupler includes sidewalls slotted at the front to engage the front crossbar and a hydraulically operated pivotable hook which engages the rear crossbar and clamps the coupler thereto.
In U.S. Pat. No. 4,480,955, the bucket includes unique coupling features, namely, a forward triangularly configured crossbar and a rearward hook. The coupler includes complementary members, namely, a transversely disposed triangular notch at the front and a hydraulically operated wedge which engages the hook. U.S. Pat. No. 4,881,867 presents a coupler configured to engage parallel transversely oriented bucket crossbars. The coupler includes a first throat for engaging the forward crossbar and a hydraulically operated movable jaw extending from the coupler housing which engages the rear bucket crossbar. U.S. Pat. No. 4,944,628 teaches a novel locking mechanism wherein a hydraulic cylinder rotates a cam to couple and uncouple a bucket and boom.
The foregoing review of prior art patents reveals that improvements in the art of such coupling mechanisms are both possible and desirable. For example, many utilize non-standard interconnecting components which may only be used with complementarily configured devices, thereby limiting their versatility and adaptability. Others require the crane or backhoe operator to dismount to connect and disconnect the attachment. This can be a time consuming and frustrating task since the operator may have to adjust the crane or boom, dismount to connect the attachment or, if the boom is not properly positioned relative to the attachment, repeatedly remount and readjust the boom before it can be connected to the attachment.
SUMMARY OF THE INVENTION
A semi-automatic coupling apparatus is permanently installed at the terminus of a backhoe dipper stick, crane boom or similar device and facilitates connection and disconnection of various earth working and material handling attachments. The coupling apparatus includes pairs of aligned, spaced-apart bushings which receive complementarily sized crossbars which extend through similarly arranged bushings in the terminal portion of the crane boom or dipper stick and secure the coupler to the boom or dipper stick. The coupler includes first, forward facing throats which engage a forward crossbar on an attachment such as a bucket and second downward facing throats which engage a rear crossbar. A latching mechanism includes a trip lever actuated by advance of the rear crossbar into the rear throats, releasing a wedge which retains the rear crossbar in the rear throats. A reset arm may be manually activated to retract the wedge and permit release of the bucket from the coupler.
The coupling apparatus facilitates addition or retrofitting to a boom or dipper stick and engagement with a bucket or other device previously coupled directly to the boom or dipper stick. An alternate embodiment of the coupler includes a remotely activated hydraulic or pneumatic cylinder which is coupled to the wedge and may be remotely controlled to couple or release a bucket or other attachment.
Thus it is an object of the present invention to provide a semi-automatic boom or dipper stick to attachment coupler.
It is a further object of the present invention to provide a boom or dipper stick to attachment coupler which facilitates ready, automatic coupling of an attachment but which must be manually activated to release the attachment.
It is a still further object of the present invention to provide a boom or dipper stick to attachment coupler having standardized coupling components facilitating retrofitting of the coupler to existing equipment in order to provide automatic coupling of attachments and manual release thereof.
Further objects and advantages of the present invention will become apparent by reference to the following specification and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a full sectional view of a bucket and semi-automatic coupling apparatus according to the instant invention disposed upon a backhoe dipper stick with the coupling apparatus partially engaged to the bucket;
FIG. 2 is a full sectional view of a bucket and semi-automatic coupling apparatus according to the instant invention disposed upon a backhoe dipper stick with the coupling apparatus fully engaged to the bucket;
FIG. 3 is an end elevational view of a semi-automatic coupling apparatus according to the present invention;
FIG. 4 is a full sectional view of a semi-automatic coupling apparatus according to the present invention in the fully engaged position;
FIG. 5 is a fragmentary elevational view in partial section of the right rear, sidewall portion of a semi-automatic coupling apparatus according to the present invention;
FIG. 6 is an exploded perspective view of a semi-automatic coupling apparatus according to the present invention; and
FIG. 7 is a side elevational view with portions broken away of a first alternate embodiment of a coupling apparatus according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 and 3, a semi-automatic coupling apparatus according to the present invention is illustrated and generally designated by the reference numeral 10. The coupling apparatus 10 includes a pair of spaced-apart, symmetrical left and right body sidewall assemblies 12A and 12B. The body sidewall assemblies 12A and 12B both define generally irregular curved peripheries and which may be chosen to satisfy both structural and esthetic considerations. The left sidewall assembly 12A includes an elongate left first, outer plate 14A and the right sidewall assembly 12B includes an elongate right first, outer plate 14B. Each of the first, outer plates 14A and 14B includes a respective one of a first pair of aligned bushings 16A and 16B disposed generally adjacent one end and a respective one of a second pair of aligned bushings 18A and 18B disposed proximate the middle.
The bushings 16A and 16B define a first axis and the bushings 18A and 18B define a second axis preferably spaced a standardized distance therefrom. The distance is chosen to correspond to the conventional design spacing between crossbars on a bucket or other attachment such that a backbone dipper stick or crane boom linkage such as the beams 20 and 22 engage the coupling apparatus 10 and translate it in the same way as a device attached directly thereto in response to positioning commands. The first pair of bushings 16A and 16B receive a front captive crossbar 24 which extends through a complementary transverse aperture in the terminal portion of the beam 20 and the second pair of bushings 18A and 18B receive a rear captive crossbar 26 which extends through a complementary transverse aperture in the terminal portion of the beam 22.
The coupling apparatus 10 may be utilized with not only a variety of cranes or backhoes (not illustrated) but also a wide variety of buckets and other earth moving equipment such as blades, picks and the like. In FIG. 1, there is illustrated a conventional bucket 30 having a plurality of teeth 32, one of which is illustrated in FIG. 1, disposed in a transversely aligned, spaced-apart array along the leading edge of the bucket 30. The bucket 30 also includes an attachment structure 34 generally adjacent the upper portion of the bucket 30. The attachment structure 34 includes a pair of parallel plates 36, one of which is illustrated in FIG. 1, which support and secure a transversely disposed front crossbar 38 and a spaced-apart parallel rear crossbar 40. The spacing between the axes of the front crossbar 38 and the rear crossbar 40 is preferably the same distance as the spacing between the axes of the bushings 16A and 16B and 18A and 18B such that the coupling apparatus 10 may be readily interposed between a boom or dipper stick and a bucket or other attachment.
It will thus be appreciated that the coupling apparatus 10 is an intermediate or adaptor-like device which is disposed between components of a backhoe dipper stick or crane boom and a bucket or other attachment where, previously, the boom or dipper stick was coupled directly to the bucket or other attachment. The width, i.e., the interior transverse axial distance between the faces of the bushings 16A and 16B and 18A and 18B, the distance marked W 1 in FIG. 3, is the same spacing between the parallel plates 36 of a conventional bucket 30 such that the terminal portions of the beams 20 and 22 of the dipper stick or boom may be received therebetween with little axial play.
The sidewall assemblies 12A and 12B further include a pair of symmetrically configured and disposed left and right second, middle plates 42A and 42B, respectively, which generally depend from and are secured to the outer plates 14A and 14B. To the opposed, interior surfaces of the plates 42A and 42B are secured respective left and right third, inner plates 44A and 44B. The third, inner plates 44A and 44B define features which receive the crossbars 38 and 40 of the bucket 30 or similarly spaced and configured mounting components of other attachments. Thus, the outside face-to-face width of the third, inner plates 44A and 44B, designated by the letter W 2 in FIG. 3, is the same as the interior bushing width W 1 . A bucket 30 or other attachment having a width W 2 between the parallel plates 36 which was fabricated to receive the transverse terminal portions of the beams 20 and 22 of a dipper stick or boom will receive the coupling apparatus and specifically the mounting plates 44A and 44B without shims, spacers or other instrumentalities.
Referring now to FIGS. 3, 4 and 5, there is disposed and secured on the opposed surfaces of the third, inner plates 44A and 44B a first pair of identical, irregular interior plates 46A and 46B disposed adjacent the front of the coupling apparatus 10 and a second pair of identical, irregular interior plates 48A and 48B disposed adjacent the rear of the coupling apparatus 10. A protective cover 50 extends between the second, middle plates 42A and 42B. The cover 50 generally conforms to the profile of the upper edge of the third, inner plates 44A and 44B and protects the mechanism of the coupling apparatus 10 from dirt and debris.
The sidewall assemblies 12A and 12B including the plates 14A and 14B, 42A and 42B, 44A and 44B, 46A and 46B and 48A and 48B are preferably steel and are secured together by welding or other suitable high strength fastening means such as fasteners and the like. Alternatively, the stepped configuration of the sidewall assemblies 12A and 12B, including the panels 14A and 14B, 42A and 42B, 44A and 44B, 46A and 46B and 48A and 48B, may be achieved by machining from solid metal stock or the assemblies 12A and 12B may be fabricated by a combination of such components and processes.
The left and right sidewall assemblies 12A and 12B are spaced-apart and secured together by a plurality of metal plates or panels extending and secured therebetween by welding. A first transverse panel 60 extends between the third, inner plates 44A and 44B generally adjacent a lower linear edge of the interior plates 46A and 46B. A second transverse panel 62 likewise extends between and is secured by weldment to the third, inner plates 44A and 44B and interior plates 46A and 46B. The second transverse panel 62 defines a centrally disposed through opening 64 and a pair of smaller, vertically aligned openings 66A and 66B. A third transverse panel 68 also extends between and is secured to the inner plates 44A and 44B and is aligned with a lower edge thereof. Spaced from and parallel to the panel 68 is a fourth transverse panel 70 which is similarly disposed and secured between the third, inner plates 44A and 44B. The third transverse panel 68 and the fourth transverse panel 70 define a transversely elongate passageway 72 therebetween. A rectangular aperture 74 is formed in the fourth transverse panel 70. Finally, a fifth transverse panel 76 extends between the sidewall assemblies 12A and 12B adjacent the rear of the coupling assembly 10 in contact with the ends of the plates 42A and 42B, 44A and 44B and 48A and 48B. The fifth panel 76 is secured to the just recited plates by weldments. A plate 78 disposed parallel to and intermediate the sidewall assemblies 12A and 12B is coupled to the panel 76 by welds and defines an oval aperture 80 which may receive a chain, hook or other lifting device which may, in turn, be utilized to conveniently raise and transport objects which are not readily moveable within the bucket 30 or other attachment to the coupling apparatus 10.
With continuing reference to FIGS. 3, 4 and 5, it will be appreciated that the first pair of irregular plates 44A and 44B define a first pair of spaced-apart aligned throats 86A and 86B. The throats 86A and 86B define semi-circular re-entrant regions having tangentially extending sidewalls. The adjacent interior plates 46A and 46B define a second pair of smaller diameter throats 88A and 88B having a diameter just slightly larger than the diameter of the crossbar 38. The second pair of aligned throats 88A and 88B likewise define a semi-circular re-entrant region having generally similar though shorter tangentially extending sidewalls. The distinct diameters of the first pair of throats 86A and 86B and the second pair of throats 88A and 88B provide distinct functions. The slightly larger size of the first pair of throats 86A and 86B assist alignment of the front crossbar 38 of a bucket 30 with the coupling assembly 10 whereas the smaller size of the second pair of throats 88A and 88B relatively closely engages the crossbar 38 and thus minimizes unwanted movement or play between the coupling apparatus 10 and the bucket 30.
It will thus be appreciated that the first pair of throats 86A and 86B function with the front crossbar 38 as positioning and alignment members whereas the second pair of throats 88A and 88B function as the actual front crossbar 38 engagement members and load bearing structures.
At the opposite end of the coupling apparatus 10 the third inner panels 44A and 44B define a third pair of spaced-apart aligned throats 90A and 90B defining semi-circular re-entrant regions having tangentially extending sidewalls. The adjacent interior plates 48A and 48B define a fourth pair of spaced-apart throats 92A and 92B, respectively. The throats 92A and 92B define a semi-circular region and each includes a tangentially extending sidewall. The third pair of throats 92A and 92B have a larger diameter and act as an aligning and positioning components for the rear crossbar 40 whereas the fourth pair of throats 92A and 92B act as engagement and load bearing members having a diameter just slightly larger than the diameter of the rear crossbar 40 thereby engaging and receiving the crossbar 40 with little play or movement. The first and the second pair of throats 86A and 86B and 88A and 88B open, i.e., define lines of access, at an angle preferably 90° to the line of access of the third and the fourth pair of throats 90A and 90B and 92A and 92B.
It will be appreciated that the center axes of the first pair of throats 86A and 86B and 88A and 88B are coaxial. Likewise, the center axes of the third pair of throats 90A and 90B and the fourth pair of throats 92A and 92B are coaxial. The distance between the axis of the first and the second pair of throats 86A and 86B and 88A and 88B and the third and the fourth pair of throats 90A and 90B and 92A and 92B preferably defines the standardized center-to-center distance between the transversely disposed crossbars 38 and 40 of the bucket 30. It will also be appreciated that the reference to and description of pairs of throats relates to and results from the utilization of the pair of spaced-apart sidewall assemblies 12A and 12B which define and include the throats 86A and 86B, 88A and 88B, 90A and 90B and 92A and 92B. The coupling apparatus 10, however, could readily be constructed with a continuous, solid transverse member defining the front crossbar 38 engaging throats 88A and 88B and a substantially continuous transverse member defining the rear crossbar receiving throats 92A and 92B which would be referred to as the front throat and the rear throat. In other words, with regard to the term throats, it should be construed to include a single, continuous or substantially continuous throat or a pair of spaced-apart throats as such constructions are equivalent and contemplated by the inventor.
The lower aperture 66A of the interior panel 62 receives a bolt 98 which is threadably received within and secures a stanchion 100 on the opposite face of the second transverse panel 62. The stanchion 100 includes a radially extending through aperture 102 which receives a pivot pin 104 which in turn pivotally supports a clevis assembly 106. The clevis assembly 106 likewise includes a pair of opposed aligned openings 108 which receive the pivot pin 104. The pivot pin 104 functions as the fulcrum for the clevis assembly 106 which operates as a first class lever. A stub shaft 112 extends obliquely from the clevis assembly 106. An operator bar 114 (illustrated in FIG. 2) includes a complementarily sized, axially extending blind opening 116. The operator bar 114 may be engaged upon the stub shaft 112 to pivot the clevis assembly 106 about the fulcrum defined by a pivot pin 104.
The clevis assembly 106 also defines a second pair of spaced-apart aligned apertures 118 which receive a second pivot pin 120. The second pivot pin 120 passes through a complementarily sized radially disposed aperture 122 in an actuator rod 124. The actuator rod 124 includes a step and a reduced diameter region 126 having threads 128 adjacent its terminus. The actuator rod 124 extends through the aperture 64 in the second transverse panel 62 and receives a compression spring 130 thereabout. The compression spring 130 is axially constrained between a face of the transverse panel 62 and a wedge block 132. The wedge block 132 is generally U-shaped and includes a pair of spaced-apart arms 134 which each define a spaced-apart obliquely oriented cam surface 136. Disposed between the arms 134 is an obliquely disposed latch surface 138. The wedge block 132 is constrained to translate obliquely in the passageway 72 defined by the interior panels 68 and 70.
The wedge block 132 also defines a through aperture 140 which receives the reduced diameter region 126 of the actuator rod 124. A threaded fastener such as a nut 142 retains the wedge block 132 on the actuator rod 124 and maintains the compression spring 130 thereabout. Preferably, a lock washer 144 or other anti-rotation device such as a cotter pin extending through castellations in the nut 142 (both not illustrated) is utilized to inhibit rotation of the nut 142 on the threads 128. It will be appreciated that rotation of the nut 142 not only permits preload adjustment of the compression spring 130 but also permits adjustment of the position of the wedge block 132 and particularly the oblique surfaces 136 relative to the rear crossbar 40 received within the pair of throats 92A and 92B.
A threaded fastener 148 extends through the small, upper aperture 66B of the second transverse panel 62 and retains a clevis 150 on one face thereof. The clevis 150 includes a pair of aligned spaced-apart apertures 152 which receive and retain a pivot pin 154 which, in turn, pivotally mounts a latch member 156. The latch member 156 includes a through passageway 158 having a diameter slightly larger than the pivot pin 154 which receives the pivot pin 154. The latch member 156 also defines a primary hook or latch 160 and a secondary hook or latch 162. The primary latch 160 is disposed in alignment with the latch surface 138 of the wedge block 132 and extends through the aperture 74 in the panel 70. The primary latch 160 of the latch member 156 is capable of engaging the latch surface 138 and retaining the wedge block 132 in the position illustrated in FIG. 1 such that the rear crossbar 40 may be received within the throats 92A and 92B and may be moved upwardly to release the wedge block 132 to retain the rear crossbar 40 within the throats 92A and 92B.
A first tension spring 164 extends between an aperture 166 in the latch member 156 and an attachment structure 168 such as a hook or pin disposed upon a crossbar 170. The ends of the crossbar 170 are received and secured within complementarily configured notches 172A and 172B in the second pair of irregular interior plates 48A and 48B, respectively. The first tension spring 164 biases the latch member 156 and particularly the primary latch 160 toward the wedge block 132.
Disposed in operable relationship with the latch member 156 is a pawl assembly 174. The pawl assembly 174 defines a clevis like member having a through aperture 176 which receives a transverse pin 178. The transverse pin 178 extends between and is secured to the second pair of irregular interior plates 48A and 48B. A pair of spacers 180, one of which is disposed on each side of the pawl assembly 174, are received on the transverse pin 178 and maintain the pawl assembly 174 in alignment with the latch member 156. A pawl 186 is pivotally secured to the pawl assembly 174 by a pivot pin 188 extending between and retained within aligned, spaced-apart apertures 190 in the pawl assembly 174 and through an aperture 192 in the pawl 186 having a diameter slightly larger than the diameter of the pivot pin 188. A second tension spring 194 extends between the lower portion of the pawl 186 and a captive pin 196 received within and extending between an aligned, spaced-apart pair of apertures 198. The second tension spring 194 biases the pawl 186 in a counterclockwise direction as illustrated in FIGS. 4 and 5. The pawl 186 engages the secondary latch 162 on the latch member 156 and moves the latch member 156 in a counterclockwise direction as viewed in FIGS. 4 and 5 when the pawl assembly 174 is acted upon by the rear crossbar 40 entering the third and the fourth pair of throats 90A and 90B and 92A and 92B, respectively. A third tension spring 202 is disposed between the captive pin 196 and the attachment member 168. The third tension spring 202 biases the pawl assembly 174 in a counterclockwise direction as viewed in FIGS. 4 and 5, driving the pawl assembly 174 toward the third pair of throats 90A and 90B and the fourth pair of throats 92A and 92B.
The pawl assembly 174 also includes a depending tab or ear 206. A crossbar 208 extends between and is secured to the second pair of irregular interior plates 48A and 48B. The pawl assembly 174 is illustrated in FIG. 4 in the position it assumes when the coupler apparatus 10 is coupled to a bucket 30 or other attachment. When the rear crossbar 40 of the bucket 30 descends from the throats 92A and 92B, the pawl assembly 174 rotates counterclockwise under the influence of the tension spring 202 and gravity, through an angle of about 35° at which point the ear 206 contacts the crossbar 208. The pawl assembly 174 is then in the position illustrated in FIG 1.
Referring now to FIG. 7, a first alternate embodiment of the coupler apparatus 10 is illustrated and designated by the reference numeral 10'. The alternate embodiment coupler apparatus 10' is similar to the preferred embodiment coupler apparatus 10 in most respects. Structurally, it includes the same left and right sidewall assemblies 12A and 12B, respectively, and the bushing assemblies 16A and 16B and 18A and 18B. Likewise, it includes the same aligned left and right pairs of throats, the front throats 86A and 88A and the rear throats 90A and 92A being illustrated. The alternate embodiment coupler apparatus 10' also includes the interior panels 68 and 70. The opening 74 in the upper panel 70 may be omitted, if desired. Similarly, the wedge block 132 having spaced-apart oblique surfaces 136 is utilized and disposed between the panels 68 and 70 for sliding translation.
The wedge block 132 is coupled by the use of any conventional fastener to a piston rod 210 which extends between the wedge block 132 and a single acting hydraulic or pneumatic cylinder 212. A compression spring 214 is disposed about the piston rod 210 and biases the wedge block 132 to the position illustrated in FIG. 7. A hydraulic or pneumatic hose 216 couples the interior of the hydraulic or pneumatic cylinder 212 with a source of controlled, pressurized air or hydraulic fluid (not illustrated). When air or hydraulic fluid under pressure is supplied through the hydraulic or pneumatic line 216 to the hydraulic or pneumatic cylinder 212, the piston rod 210 translates to the left as illustrated in FIG. 7, against the force of the compression spring 214, translating the wedge block 132 to the left such that the third pair of throats 90A and 90B and the fourth pair of throats 92A and 92B are open and permit entry or egress of a bucket crossbar such as the crossbar 40 associated with the bucket 30 illustrated in FIGS. 1 and 2. Upon the termination of hydraulic or pneumatic pressure, the wedge block 132 returns to the position illustrated in FIG. 7 under the force and influence of the compression spring 214. The compression spring 214 functions as a fail safe device to ensure that any attachment coupled by a crossbar member 40 within the throats 90A and 90B and 92A and 92B will remain so attached unless hydraulic or pneumatic pressure is specifically applied to permit release of such attachment. Thus, the maintenance of hydraulic or pneumatic pressure in the hydraulic or pneumatic cylinder 212 is not necessary to maintain an attachment within the coupling apparatus 10'.
The operation of the preferred embodiment coupling apparatus 10 and alternate embodiment coupling apparatus 10' will now be described. First with reference to the preferred embodiment coupling apparatus 10, it will be assumed that the operator of a crane or backhoe (both not illustrated) is desirous of engaging an attachment such as the bucket 30. Accordingly, the boom or dipper stick represented by the beams 20 and 22 and the coupling apparatus 10 are arranged relative to the bucket 30 such that the front crossbar 38 may be received within the front pair of throats 88A and 88B as illustrated in FIG. 1. During this initial linkup, it will be appreciated that the throats 86A and 86B having a slightly larger diameter assist in alignment of the throats 88A and 88B with the front crossbar 38 as previously noted.
When the front crossbar 38 is fully seated within the throats 88A and 88B, the beam 22 is extended relative to the beam 20 such that the coupling apparatus 10 pivots about the axis of the front crossbar 38 in a clockwise direction and the coupling apparatus 10 moves to the position illustrated generally in FIG. 2.
At this time, the rear crossbar 40 contacts the body of the pawl assembly 174 driving it up and counterclockwise from the position illustrated in FIG. 1 to the position illustrated in FIGS. 2 and 4. Such motion of the pawl assembly 174 engages the secondary latch 162 of the latch member 156, moving it upwardly and in a counterclockwise direction about the pivot pin 154. This motion of the latch member 156 causes the primary latch 160 to move upwardly, off the obliquely disposed latch surface 138 of the wedge block 132 thereby releasing the wedge block 132. Under the influence of the compression spring 130, the wedge block 132 translates to the right and the oblique cam surfaces 136 both engage the rear crossbar 40 of the bucket 30 and drive it upwardly into intimate engagement with the fourth pair of throats 92A and 92B. At this time, the bucket 30 is coupled to the coupling apparatus 10 and thus to the backhoe or crane (not illustrated).
To release the bucket 30, the bucket 30 is positioned on the ground or other stable horizontal surface and the operator bar 114 (illustrated in FIG. 2) is seated upon the stub shaft 112. The operator bar 114 is manually moved downwardly in a counterclockwise direction about the pivot pin 104. Through the action of the clevis assembly 106, the wedge block 132, which is coupled to the clevis assembly 106 by the actuator rod 124, is translated upwardly, to the left in FIGS. 1 and 2 until the primary latch 160 of the latch member 156 re-engages the oblique latch surface 138 of the wedge block 132. At this time, the coupling assembly 10 may be rotated about the axis of the front crossbar 38 by manipulation of the crane or boom and specifically the beam 22. As the rear crossbar 40 exits the throats 92A and 92B, the pawl assembly 174, under the influence of the third tension spring 202 resets. In the reset position, the pawl 186 is below and disposed in operable engagement with the secondary latch 162 of the latch member 156. The coupling apparatus 10, which is now generally in the position illustrated in FIG. 1, may be completely disengaged from the bucket 30 by further rotation of the coupling apparatus 10 about the front crossbar 30 and lifting thereof or moving the coupling apparatus 10 up and to the right as illustrated in FIG. 1 by appropriate adjustment of the crane or boom. It will thus be appreciated that while linkup of the coupling apparatus 10 with a bucket 30 or other attachment is automatic, that is, accomplished without manual assistance, release of said bucket 30 or other attachment requires express, manual intervention. The apparatus is thus denominated semi-automatic.
With reference now to FIG. 7, it will be appreciated that the operation of the alternate embodiment coupler apparatus 10' is similarly straightforward. The alignment and engagement of the front crossbar 38 of a bucket 30 are performed in the identical manner. To engage the rear crossbar 40 of a bucket, pressurized fluid which may be either hydraulic fluid or air, as appropriate, is supplied to the cylinder 212 through the line 216 to retract the wedge block 132 against the force of the compression spring 214 such that the rear crossbar 40 may readily be received within the fourth pair of throats 92A and 92B. The coupling apparatus 10 is then rotated such that the rear crossbar 40 fully seats within the throats 92A and 92B and pressurized fluid is released from the cylinder 212. The compression spring 214 then returns the wedge block 132 to the position illustrated in FIG. 7. It will be appreciated that the compression spring 214 functions as a fail safe device to ensure that at all times when pressurized fluid is not applied to the cylinder 212, the wedge block 132 remains extended so that a bucket 30 or other attachment is positively retained within the alternate embodiment coupling apparatus 10'. To release the bucket 30, the above recited steps are undertaken in the reverse order.
The foregoing disclosure is the best mode devised by the inventor for practicing this invention. It is apparent, however, that devices incorporating modifications and variations will be obvious to one skilled in the art of mechanical couplers. Inasmuch as the foregoing disclosure is intended to enable one skilled in the pertinent art to practice the instant invention, it should not be construed to be limited thereby but should be construed to include such aforementioned obvious variations and be limited only by the spirit and scope of the following claims.
|
A semi-automatic coupling apparatus is installed at the terminus of a backhoe dipper stick, crane boom or similar device and facilitates connection and disconnection of various earth working and material handling attachments. The coupler includes first, forward facing throats which engage a forward crossbar on an attachment such as a bucket and second, downward facing throats which engage a rear crossbar. A latching mechanism includes a pawl actuated by advance of the rear crossbar into the rear throats. The pawl releases a spring biased wedge member which retains the rear crossbar in the rear throat. A reset linkage may be manually activated to retract the wedge and permit release of the bucket from the coupler. An alternate embodiment of the coupler includes a remotely activated hydraulic or pneumatic cylinder which is coupled to the spring biased wedge member.
| 4
|
BACKGROUND OF THE INVENTION
[0001] First generation of cartridge revolvers was single action and they come with the detached cylinder for loading. Remove of a hot cylinder after firing was too hard and it was weak points of removable cylinders. Later models used a fixed cylinder with a loading gate at rear of cylinder and an under barrel rod to extract. In those revolvers only one chamber is exposed at a time and it waste a lots of time to unload the shells and reload the cartridges. To solve above problem, designers develop the top break and swing out cylinders with extractor to improve the revolver and make the reloading easier. But nobody try to design a revolver with ejector. Six years ago when I read an article about handguns and compare between semi autos and revolvers, I got an idea to design a revolver with ejector system. This design is result of my research.
BRIEF SUMMERY OF THE INVENTION
[0002] This is a double action revolver with the concealed hammer. This revolver is available in .357 magnum caliber but this design is feasible on other usual calibers of revolvers. Capacity of the cylinder is 8 rounds and barrel length is 4″. For the unprofessional views, external shape of this gun is same as other revolvers but everything is different, specially 95 percent of the internal parts are totally new with different mechanism. Biggest invention on this design is the ejector system. It means, after each fire, shell pulled out of the gun. In addition to the new safety systems, this gun designed with the new safety lever. Another innovation in this revolver is disassembling and reassembling of parts just by levers, simple and without usage of any tools. I believe my design make an evolution in revolver guns.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 page 1 / 34 is a perspective view of the revolver.
[0004] FIG. 2 page 2 / 34 is a side view of the revolver.
[0005] FIG. 3 page 3 / 34 is a top view of the revolver.
[0006] FIG. 4 page 4 / 34 is a front view of the revolver.
[0007] FIG. 5 page 4 / 34 is a back view of the revolver.
[0008] FIG. 6 page 5 / 34 is exploded view of the revolver. to see the parts list please refer to the Detailed Description of the Invention, paragraph [0105].
[0009] FIG. 7 page 6 / 34 is overall view of the revolver.
[0010] FIG. 8 page 7 / 34 is cutaway of the revolver. Parts list is same as FIG. 6 .
[0011] FIG. 9 page 8 / 34 shows the Trigger mechanism.
[0012] FIG. 10 page 8 / 34 shows the Trigger in action.
[0013] FIG. 11 page 9 / 34 shows the Internal Cylinder.
[0014] FIG. 12 page 9 / 34 shows the exploded view of the Internal Cylinder components.
[0015] FIG. 13 page 10 / 34 shows the Cylinder (feed system) and its situation in the Frame.
[0016] FIG. 14 page 10 / 34 shows the exploded view of the Cylinder parts.
[0017] FIG. 15 page 10 / 34 shows the Yoke.
[0018] FIG. 16 page 10 / 34 shows the Ratchet mechanism.
[0019] FIG. 17 page 11 / 34 shows the Yoke latch and its mechanism.
[0020] FIG. 18 page 11 / 34 shows the Frame Hole and its situation on the Frame.
[0021] FIG. 19 page 11 / 34 shows how the Transfer Pin block the rotary motion of Rotator.
[0022] FIG. 20 page 12 / 34 shows the situation of the Rotator at open position of Cylinder.
[0023] FIG. 21 page 12 / 34 shows the situation of the Rotator when user close the Cylinder.
[0024] FIG. 22 page 12 / 34 shows the situation of the Rotator at close position of Cylinder.
[0025] FIG. 23 page 13 / 34 is internal parts at the rest condition of revolver.
[0026] FIG. 24 page 13 / 34 shows the movement of internal parts, when we pull the Trigger.
[0027] FIG. 25 page 14 / 34 shows the continuous movement of internal parts.
[0028] FIG. 26 page 14 / 34 shows the spring loaded Hammer in cocked position.
[0029] FIG. 27 page 15 / 34 shows the release of Hammer and Transfer Pin.
[0030] FIG. 28 page 15 / 34 shows strike of the Firing Pin by Hammer and fire of bullet.
[0031] FIG. 29 page 16 / 34 shows the movement of internal parts after fire, and rotation of Rotator.
[0032] FIG. 30 page 16 / 34 shows the condition of shell under the Eject Port.
[0033] FIG. 31 page 17 / 34 shows the ejection of shell by the Ejector Spring.
[0034] FIG. 32 page 17 / 34 is internal parts after end of a firing cycle.
[0035] FIG. 33 page 18 / 38 shows the lock mechanism of the Firing Pin.
[0036] FIG. 34 page 18 / 34 shows the release of the Firing Pin from lock position.
[0037] FIG. 35 page 19 / 34 is safety system of Hammer to isolate it from Firing Pin.
[0038] FIG. 36 page 19 / 34 shows the Hammer Safety System after squeeze of the Trigger.
[0039] FIG. 37 page 19 / 34 shows condition of the Hammer Safety System after strike.
[0040] FIG. 38 page 19 / 34 shows movement of Hammer Safety System after firing.
[0041] FIG. 39 page 20 / 34 is the Releaser Button at rest condition.
[0042] FIG. 40 page 20 / 34 shows the push of the Releaser Button.
[0043] FIG. 41 page 20 / 34 shows the action of Releaser Button Safety System.
[0044] FIG. 42 page 21 / 34 shows The Dent of Frame.
[0045] FIG. 43 page 21 / 34 shows an non ejected shell because of problem in Ejector Spring.
[0046] FIG. 44 page 21 / 34 shows how Frame Dent, return of non ejected shell to chamber.
[0047] FIG. 45 page 22 / 34 shows the situation of Gaps on the Hinge of Rotator Cover.
[0048] FIG. 46 page 22 / 34 shows the situation of Gaps and Trigger Tooth, when the Cylinder is close.
[0049] FIG. 47 page 22 / 34 shows the situation of Gaps and Trigger Tooth, after pull of Trigger.
[0050] FIG. 48 page 22 / 34 shows the situation of Gaps and Trigger Tooth, at opening of Cylinder.
[0051] FIG. 49 page 22 / 34 shows the situation of Gaps and Trigger Tooth, when the Cylinder is completely open.
[0052] FIG. 50 page 23 / 34 shows the engage of Transfer Pin and Extractor when the Cylinder is Close.
[0053] FIG. 51 page 23 / 34 is Rotator in adjusted position, when Cylinder is open.
[0054] FIG. 52 page 23 / 34 is Rotator in adjusted position, when closing of Cylinder.
[0055] FIG. 53 page 23 / 34 is Rotator in unadjusted position, when Cylinder is open.
[0056] FIG. 54 page 23 / 34 shows how the Transfer Pin blocked the unadjusted Rotator.
[0057] FIG. 55 page 24 / 34 shows the Safety Lever at fire mode or safe mode from view of operator.
[0058] FIG. 56 page 24 / 34 shows the Lock System and its internal parts at the fire mode.
[0059] FIG. 57 page 24 / 34 shows the turning of Lock System to the safe mode.
[0060] FIG. 58 page 24 / 34 shows the Lock System and its internal parts at the safe mode.
[0061] FIG. 59 page 25 / 34 shows how load of revolver.
[0062] FIG. 60 page 25 / 34 shows how load of revolver.
[0063] FIG. 61 page 25 / 34 shows how load of revolver.
[0064] FIG. 62 page 25 / 34 shows how load of revolver.
[0065] FIG. 63 page 26 / 34 shows how unload of revolver.
[0066] FIG. 64 page 26 / 34 shows how unload of revolver.
[0067] FIG. 65 page 26 / 34 shows how unload of revolver.
[0068] FIG. 66 page 26 / 34 shows how unload of revolver.
[0069] FIG. 67 page 27 / 34 shows the mechanism of Bolt to release the Cylinder.
[0070] FIG. 68 page 27 / 34 shows the opening of Cylinder.
[0071] FIG. 69 page 27 / 34 shows the Extractor mechanism to unload the gun.
[0072] FIG. 70 page 28 / 34 shows the Yoke Latch mechanism to lock the Cylinder Unit.
[0073] FIG. 71 page 28 / 34 shows removing of the Cylinder Unit from the Frame.
[0074] FIG. 72 page 29 / 34 shows opening of Cylinder Unit components.
[0075] FIG. 73 page 29 / 34 shows how to opening of the Extractor Rod.
[0076] FIG. 74 page 29 / 34 shows opening of Rotator components.
[0077] FIG. 75 page 29 / 34 shows how to release the Pawl and its Spring from Yoke.
[0078] FIG. 76 page 29 / 34 shows opening of the Yoke Latch, its Cover and its Spring.
[0079] FIG. 77 page 30 / 34 shows situation of Barrel Latch on the Frame.
[0080] FIG. 78 page 30 / 34 shows engage of Barrel Latch with Barrel and Barrel shroud.
[0081] FIG. 79 page 30 / 34 shows how the Barrel Latch release the Barrel and Barrel shroud.
[0082] FIG. 80 page 30 / 34 shows release the Barrel Shroud from the Frame.
[0083] FIG. 81 page 30 / 34 shows rotation of Barrel to release it.
[0084] FIG. 82 page 30 / 34 shows remove of the Barrel from the Frame.
[0085] FIG. 83 page 30 / 34 shows remove of the Barrel Latch, its Cover and its Spring from the Frame.
[0086] FIG. 84 page 30 / 34 shows release of the Front Sight from the Barrel Shroud.
[0087] FIG. 85 page 30 / 34 shows opening of the Locking Bolt Cover and release of the Locking Bolt and its Spring.
[0088] FIG. 86 page 31 / 34 shows the removing of the Grip Cover from Grip.
[0089] FIG. 87 page 31 / 34 shows the mechanism of Grip Latch Lever and how to remove the Grip.
[0090] FIG. 88 page 31 / 34 shows the release of Frame Cover, Strain Lever and Grip Latch Lever.
[0091] FIG. 89 page 31 / 34 shows how release of Strain Lever from its Flat Spring and Grip Latch Lever parts.
[0092] FIG. 90 page 32 / 34 shows how to remove the Side Plate and Trigger Cover.
[0093] FIG. 91 page 32 / 34 shows how to remove the Hammer and Main Spring.
[0094] FIG. 92 page 32 / 34 shows disassemble of the Main Spring, Hammer and Sear.
[0095] FIG. 93 page 32 / 34 shows remove of the Trigger, Internal Cylinder and Bolt.
[0096] FIG. 94 page 32 / 34 shows disassemble of the Trigger, Internal Cylinder and Bolt.
[0097] FIG. 95 page 33 / 34 shows the removing condition of Lock System from the Frame.
[0098] FIG. 96 page 33 / 34 shows the removing condition of Firing Pin from the Frame.
[0099] FIG. 97 page 33 / 34 shows removing of the Rear Sight to install the Scope Mounts.
[0100] FIG. 98 page 34 / 34 shows how to adjust the amount of pressure on the Trigger without tools.
[0101] FIG. 99 page 34 / 34 shows adjust the amount of pressure on the Trigger by a screwdriver.
[0102] All of drawings designed and drawn by myself.
DETAILED DESCRIPTION OF THE INVENTION
[0103] This is an automatic revolver, it means after firing, ejection mechanism pull out the shell until all cartridges have been fired. After finish of rounds, when you open the cylinder, there is no shell in the chambers. Therefore it decrease time of reloading and at minimum time we have a revolver ready to fire. I have tried to remove the weak points of revolvers in compare with the semi auto handguns. First step, I add an ejector system to this revolver. Second, I have designed a safety lever for this revolver to provide the maximum safety in addition of the new internal safety system. This design is unique among all type of revolvers and firearms because, there is no screw involve in revolver. Only the Extractor Rod has helical ridges. It reduces the production costs and makes the gun easy to repair. Usually you need special wrenches to complete disassemble and reassemble of each handgun. But In this design, complete disassemble and assemble of revolver even opening of the barrel is possible without any kind of tools.
[0104] My design is double action only and hammer of the gun totally concealed. This is safer than external hammers, specially for the operator. For the easier and faster acquisition of target I have designed a three dot sight for this revolver. Self illuminated dots are highly visible in the dark areas. Also frame of this gun is drilled and ready to install the scope mounts. A good grip improves control of the gun during firing sequences. Ergonomically designed rubber grip with finger grooves provide the confidence to control of the revolver even when wet. Ninety five percent of internal parts and its mechanism are new. I have tried to design the fewer internal parts to better reliability and durability. Usage of common springs in internal parts decrease the manufacturing cost. There are no springs under stress in revolver when you storing your gun without bullet. To see the 3 view and perspective view of the gun please see FIG. 1 to 5 .
[0105] To description of the gun mechanism, first I have to explain about some of the internal parts and components. Exploded view, FIG. 6 shows the internal and external parts of the gnu. FIGS. 7 & 8 shows the overall view and cutaway of the gun. For better understood of descriptions, name of each part come with its number according to this parts list.
PARTS LIST
[0000]
1 —Front Sight
2 —Barrel Shroud
3 —Locking Bolt Cover
4 —Locking Bolt Spring
5 —Locking Bolt
6 —Barrel
7 —Extractor Rod
8 —Extractor Spring
9 —Center Pin Spring
10 —Center Pin
11 —Yoke Latch
12 —Yoke Latch Spring
13 —Yoke
14 —Pawl
15 —Pawl Spring
16 —Yoke Latch Cover
17 —Rotator
18 —Flat Ejector Springs
19 —Extractor
20 —Rotator Cover
21 —Frame
22 —Barrel Latch Cover
23 —Barrel Latch
24 —Barrel Latch Spring
25 —Rear Sight
26 —Side Plate
27 —Safety Lever
28 —Firing Pin
29 —Firing Pin Spring
30 —Firing Pin Cover
31 —Releaser Button and Bolt
32 —Bolt Spring
33 —Lock System Flat Spring
34 —Lock System
35 —Main Spring
36 —Hammer
37 —Sear
38 —Sear Torsion Spring
39 —Stirrup Pin
40 —Stirrup
41 —Internal Cylinder
42 —Piston Spring
43 —Piston
44 —Transfer Pin
45 —Transfer Pin Torsion Spring
46 —Connecting Rod
47 —Trigger
48 —Trigger Cover
49 —Frame Cover
50 —Strain Lever Flat Spring
51 —Strain Lever
52 —Grip Latch Lever
53 —Grip Latch
54 —Grip Latch Spring
55 —Grip Latch
56 —Grip Cover
57 —Grip
Trigger System
[0163] Please refer to the FIG. 9 and FIG. 10 , Trigger 47 seems a lever action but it is a hinged action trigger. I have designed a unique trigger specially for this revolver. Trigger 47 is linked to the Piston 43 of Internal Cylinder 41 , by Push Rod 46 . Squeeze of the Trigger 47 , press this Piston 43 against its Spring 42 . After firing, Spring of the Piston 42 return back the Trigger 47 to the initial condition. Trigger 47 is DAO (Double Action Only) and it does these jobs:
[0164] 1—Cock the Hammer 36 .
[0165] 2—Press the Piston 43 of Internal Cylinder 41 against its Spring 42 .
Internal Cylinder
[0166] Internal cylinder 41 is heart of this revolver and plays seven important roles in this gun. To see the components and mechanism of internal cylinder please see the FIG. 11 and FIG. 12 . as I described, Trigger 47 linked to the Piston 43 by a Push Rod 46 and its transfer, movement of Trigger 47 to the Piston 43 of Internal Cylinder 41 against a Compression Spring 42 . There is a Transfer Pin 44 beside of Piston 43 . It's able to move back against of a Torsion Spring 45 . In the initial condition of Piston 43 (when internal parts are at the rest) end of Transfer Pin 44 blocked by Internal Cylinders 41 jag and it can't travel back. See the FIG. 11 . Just squeeze of Trigger 47 and move up the Piston 43 release the end of Transfer Pin 44 and it would move back. Internal Cylinder 41 unit played these important jobs:
1—Spring 42 of Piston 43 , play role of the triggers spring and after squeeze, return it back to the initial condition. 2—Piston Bolt FIG. 12 , locks the Firing Pin 28 at the rest condition for safety reasons (I will explain in Safety Systems regarding this action). 3—Piston Stopper FIG. 12 , detach the Hammer 36 from the Firing Pin 28 for safety reasons (I will explain in Safety Systems regarding this action). 4—Piston Tooth FIG. 12 , lock the Bolt and Releaser Button 31 at the firing cycle for safety reasons (I will explain in Safety Systems regarding this action). 5—Transfer Pin 44 , provide the rotary motion for the Rotator 17 in firing cycle (I will explain in Firing Mechanism regarding this action). 6—Transfer Pin 44 , block the rotary motion of Rotator 17 at the rest condition of gun (I will explain in Unit of Cylinder regarding this action). 7—Transfer Pin 44 , blocked the unadjusted Rotator 17 , when user close the open Cylinder (feed system) for safety reasons (I will explain in Safety Systems regarding this action).
Unit of Cylinder (Feed System)
[0174] One of the biggest differences between this revolver and usual revolvers is this Cylinder because it's fixed in its place and doesn't rotate. The Unit of Cylinder is mounted on a hinge and swing out to the left side of frame to load or reload. There is 2 point Cylinder lockup FIG. 13 . Capacity of this Cylinder is 8 rounds of .357 magnum cartridges. Ejector system (Ejector Tooth, Eject Port & Flat Ejector Springs 18 ) is installed on the Cylinder, FIG. 13 . In the revolver guns when you squeeze the trigger, it turns the cylinder and cocks the hammer, later release the cocked hammer to strike the primer. On the other hand, rotary motion of cylinder is before the firing of the revolver. But in this design Trigger cock the Hammer, release it to fire the gun then Internal Cylinder turn the Rotator 17 of Cylinder (Feed System). To see the component of Cylinder (Feed System), refer to the FIG. 14 .
[0175] FIG. 14 , Unit of Cylinder is included: Yoke 13 , Rotator 17 and Cover of Cylinder 20 . Cylinder is fixed in its place and just Rotator 17 is able to rotary motion. Chambers are on the Rotator 17 . To prevent of gas licking, bullet and two millimetre of its case insert to the circular part of chamber. Rest of the bullet case insert in the U-Shape of chamber FIG. 14 .
[0176] There is a Round Gear in the front side of Rotator 17 . Each tooth of the Gear has a steeply slopes edges and gently slopes in the other sides. For better understanding I add a rotated view of Rotator 17 to FIG. 14 .
[0177] Refer to the FIG. 15 , there is a Pawl 14 and Flat Spring 15 on the Yoke 13 . Engagement of this Pawl 14 and Round Gear of Rotator played role of a Ratchet FIG. 16 . Specific shape of the Round Gear and pressure of Pawl's Flat Spring 15 adjust the Rotator 17 at specified points. At these points Chambers are exactly aligned of the Barrel. Rotator 17 just rotates in clockwise because of Ratchet FIG. 16 .
[0178] Refer to the FIG. 17 , There is a Latch 11 inside the Yoke 13 . Push inward of Yoke Latch 11 , against its Spring 12 engage the Latch Pin and Ratchet together and locked the Rotator 17 . There is a Hole at this point of Frame FIG. 18 Yoke Latch 11 fixed in this place. Yoke Latch 11 play two important roles:
1—It locked the Unit of Cylinder in the Frame exactly same as a lock bolt. 2—When you open or close the Cylinder Unit, special shape of the Frame Hole, FIG. 18 push up the Yoke Latch 11 against of Latch Spring 12 and locked the Rotator 17 .
[0181] Refer to the FIG. 19 (for better understanding, Cover of Cylinder 20 is transparent in this view) at the rest condition of revolver and close position of Cylinder Unit, endpoint of Transfer Pin 44 is locked by Cylinder Jag 41 and it is not able to move back. Transfer Pin 44 engaged to Extractor Gear 19 and lock the Rotator 17 to prevent of turn it clock wise.
[0182] FIG. 20 is front view of the revolver. In this condition Cylinder is completely open, Rotator 17 is free to rotary motion left side in the adjusted points and right side motion is not possible, because of Ratchet.
[0183] FIG. 21 , When we close the Cylinder, Frame Hole push up the Yoke Latch 11 and pin of the Yoke Latch engage the Ratchet Gear and lock the Rotator 17 totally. In this position rotary motion of Rotator 17 is impossible.
[0184] FIG. 22 , In the complete close position of Cylinder, Frame Hole let the Yoke Latch's Spring 12 to push down the Yoke Latch 11 and release the Ratchet gear, but Rotator 17 is not able to turn. In this position Ratchet, prevent the Rotator 17 from turning right and Transfer pin FIG. 19 , prevent the rotator 17 from turning left.
Fire Mechanism
[0185] Now I explain about the firing mechanism of this revolver. Please see the FIG. 23 , this is Initial condition. Revolver is at rest. For better understanding of firing mechanism, Cover of Cylinder is transparent, also I add another view from back side of Cylinder to the FIG. 23 to 32 . Situation of Cylinder Cover 20 , Rotator 17 , Transfer Pin 44 , Extractor Gear 19 , Ratchet, Ejector Port and Ejector Tooth is clear.
[0186] FIG. 24 , Trigger 47 squeezed by operator. Same as double action guns, Trigger 47 is in engaged position with the Sear 37 . Pull the Trigger 47 loaded the Hammer 36 against Main Spring 35 . Trigger 47 linked to the Piston 43 of Internal Cylinder 41 by a Push Rod 46 and move up the Piston 43 in Internal Cylinder 41 against Piston Spring 42 . Transfer Pin 44 (inside of the Piston) slide up on the Extractor Gear 19 and travel back against its Torsion Spring 45 , but it is not able to turn the Rotator 17 because of ratchet.
[0187] FIG. 25 , Movement is Continuous.
[0188] FIG. 26 , Spring loaded Hammer 36 is in cocked position and ready to strike.
[0189] FIG. 27 , Small amount of pressure on the Trigger 47 , release the tensioned Hammer 36 . Also Transfer pin 44 is in the end of Ratchet Gear 19 and latched with it by push of its Torsion Spring 45 .
[0190] FIG. 28 , In this view head of Hammer 36 and Barrel Cutted for better understanding. Hammer 36 strike the Firing Pin 28 and Firing Pin strike the primer of chambered cartridge and fire the bullet.
[0191] FIG. 29 , After firing, When operator release the Trigger 47 , Piston Spring 42 push down the Piston 43 and try to return back the Trigger 47 to the first position. With move down of Piston 43 , Transfer Pin 44 (now latched with Extractor Gear 19 ) move down too and turn the Rotator 17 . By turning Rotator 17 , rim of the shell slide on Ejector Tooth, pulled back and released from the circular shape of chamber. Movement of Ratchet component is clear at back view of the Cylinder.
[0192] FIG. 30 , Movement is Continuous and Trigger 47 push back the Sear 37 against its Torsion Spring 38 to engage with it again. Stopper of piston push back the Hammer 36 .
[0193] FIG. 31 , By rotary motion of Rotator 17 , shell goes under the Eject Port. Now shell is without protect of Cylinder Cover 20 and shoot off by pressure of Ejector Flat Spring 18
[0194] FIG. 32 , Movement is Continuous and return the internal parts to initial condition. One firing cycle is complete.
Safety Systems
[0195] First precedence for the gun designers is safety of the gun. There are six safety systems and a safety lever to maximized safety of this revolver. If you drop or roughly handle the loaded weapon, accidental discharge never happened.
[0196] To prevent of accidental discharge, Firing Pin 28 has a Tooth, it is engaged and blocked by Piston Bolt when it is at rest FIG. 33 .
[0197] Firing Pin 28 unlocked when the Trigger 47 is pulled by operator FIG. 34 . Because pulling of the Trigger 47 , move up the Piston 43 and Piston Bolt doesn't obstruct the Firing Pin Tooth.
[0198] The Hammer 36 itself cannot contact the Firing Pin 28 to prevent accidental discharge FIG. 35 . There is a Stopper in the back side of Piston 43 and it isolates the Hammer 36 from Firing Pin 28 .
[0199] By pull the Trigger 47 and move up the Piston 43 , Stopper moved up too FIG. 36 . [ 0142 ] When the Hammer 36 strikes the Firing Pin 28 , Stopper goes exactly in the Hammer's Hole and it is not between Hammer 36 and Firing Pin 28 . FIG. 37 , For better understanding head of Hammer shows cutted at FIGS. 37 & 38
[0200] After discharge and release of the Trigger 47 by user, Spring of Piston 42 pushed down the Piston 43 and Stopper. FIG. 38 , Inclined surface shape of Stopper slides up and push backward the Hammer 36 . In this position until initial condition, Stopper is between Hammer 36 and Firing Pin 28 and isolate those again.
[0201] To prevent accidental opening of Cylinder Unit in the firing cycle, I add another new safety device to this revolver. When Trigger 47 is at rest, you can push the Releaser Button 31 against its Spring 32 and open the Cylinder to reload or unload the weapon FIGS. 39 & 40 .
[0202] By squeeze of Trigger 47 and move up the Piston 43 , Pistons Tooth locked the Bolt and Releaser Button 31 FIG. 41 . Until end of firing cycle and return of the Trigger 47 to initial condition, Releaser Button 31 will be locked.
[0203] Misfire (Failure to Discharge) is an important problem it sometimes occurred in automatic firearms. Damaged cartridge is main reason of this problem. Misfire caused to malfunction, stop, and even damaged of the gun. To prevent of this problem I have designed a new safety system.
[0204] There is a Dent on frame of this revolver in the back side of cylinder FIG. 42 . When Ejector Tooth, pulls back the shell, end point of the shell goes exactly in this Dent FIG. 43 . If the cartridge doesn't fire because of any problem in primer or powder, after pull back of cartridge by Ejector Tooth, Flat Ejector Spring (under the shell) is not able to shoot out the cartridge because bullet is still in the Chamber and it is stuck the cartridge. Rotary motion of the Rotator 17 and special shape of Dent (same as inclined surface) push forward the damaged cartridge in chamber to the initial condition FIG. 44 , and it doesn't make problem for the next firing cycle. After firing, operator can use the extractor to unload the damaged cartridge.
[0205] If the Cylinder Unit does not closed completely and latched in its place, firing of the gun is impossible because of a new safety system. Action of the Trigger is depending on the Cylinder condition. Cover of the Cylinder 20 has two gaps on its Hinge FIG. 45 .
[0206] FIG. 46 , There is a Tooth on the front side of Trigger 47 . When Triggers Tooth and Hinge Gap are alignment of each other, Trigger 47 is able to work. This is possible when the Cylinder is in close condition or complete open condition FIG. 47 .
[0207] When you open the Cylinder FIG. 48 , by swing out of Cylinder, Hinge Gaps turn from front of Triggers Tooth and edge of the Covers Hinge, block the Triggers Tooth.
[0208] In the complete open condition of the Cylinder another gap of Cylinder Hinge is in front of Trigger Tooth and action of Trigger 47 is possible again FIG. 49 .
[0209] Lack of the alignment between chamber and barrel is a dangerous condition in the revolver guns. Sometimes when the operator close the cylinder quickly with the flick of the wrist, the cylinder latched but chamber and barrel are out of alignment and it caused bullet damage, stuck of the bullet and even explode of the cylinder. It is the weak point of swing out cylinder designs. This problem never occurred at this design because Cylinder Ratchet keeps the Rotator at Adjusted points FIG. 16 . If the chamber is not aligned to the barrel because of any problem in the cylinder, you can't close the cylinder completely and when the cylinder is not latched in its place trigger doesn't action because of above safety system. Refer to the line [0148].
[0210] As I described Transfer Pin 44 is locked at the rest condition (by Internal Cylinder Jag) FIG. 50 .
[0211] FIG. 51 Shows the adjusted place of Rotator 17 when Cylinder is open. Round Gear of Extractor is adjusted to never become engage with Transfer Pin 44 at the closing of Cylinder FIG. 52 .
[0212] when the Rotator 17 is in unadjusted place, FIG. 53 , Round Gear of Extractor is unadjusted too and Transfer Pin 44 blocked it at closing position FIG. 54 . If the Cylinder can't completely close, Trigger doesn't work.
[0213] The Safety Lever 27 , situated above Releaser Button 31 in the back side of revolver FIG. 55 . When the operator focused on the sights to aim the target, Safety lever 27 is under view of operator and the user understand the gun is in fire mode or not, without looking at another place except target. Action of this lever is easily possible with thumb of the firing or supporting hand. Usage of this lever is comfortable for both right hand and left hand operators. Refer to FIG. 56 , Components of Lock System 34 are: Lever 27 , Lock Bolt and Flat Spring 33 . Also there is a tooth beside of Hammer 36 to engage with Lock System.
[0214] FIG. 56 , I add a reverse angle view from lock system to FIG. 56 to 58 for better understanding. In this condition FIG. 56 , revolver is in fire mode. Lock Bolt is in up position and doesn't block the Hammer Tooth.
[0215] FIG. 57 , By turn up of the Safety Lever 27 against pressure of its Flat Spring 33 , Lock Bolt, it linked to the Safety Lever Button 27 turn down, engage with Hammer Tooth and lock it.
[0216] FIG. 58 , Now revolver is at safe state. Lock Bolt is in front of Hammer Tooth, against of Hammer 36 movement and it prevent the firing mechanism from moving.
Load and Reload of the Revolver
[0217] You have to load the gun to prepare it to use. Loading of this revolver is simple. To Load the gun: Point the gun in a safe direction.
[0218] To open the Cylinder, push the Releaser Button 31 inward FIG. 59 .
[0219] Hold the Releaser Button 31 , push the Cylinder 20 and Swing it out completely from the left side of the revolver FIG. 60 .
[0220] You can place individual cartridges in to the chambers or load the gun with a speed loader at once. You should push the cartridges to the chambers firmly because flat ejector springs are against insert of cartridges FIG. 61 .
[0221] Push the Cylinder 20 in to frame completely and close it FIG. 62 .
[0222] To unload the gun: Point the barrel in a safe direction.
[0223] To open the Cylinder, press the Releaser Button 31 inward FIG. 63 .
[0224] Hold the Releaser Button 31 , push the Cylinder 20 and Swing it out completely from the left side of the revolver FIG. 64 .
[0225] Press the Push Rod 7 , firmly and release all of the cartridges. Allow push rod to return forward under its spring pressure FIG. 65 .
[0226] Push the Cylinder 20 in to frame completely and close it FIG. 66 .
Disassemble and Reassemble of the Gun
[0227] When you want to disassemble a revolver, at least you need a screwdriver to remove the side plate. After that you have access to the internal parts. Specific wrench is necessary to release the barrel from the frame. I have designed a revolver same as automatic guns, it's disassembled by levers.
[0228] Even for complete disassemble of semi autos you need the three or four kind of tools, but in my design you are needless of any tools to assemble or disassemble of the gun. Also replacing of the defective parts can be done easily in least time.
[0229] Refer to the FIG. 7 , compression springs no. 4 , 9 , 12 , 24 , 29 , 32 , 54 and torsion springs no. 38 & 45 are same to decrease the manufacturing cost.
[0230] To disassemble: Point the gun in a safe direction.
[0231] Press the Releaser Button 31 inward to open the Cylinder FIG. 67 .
[0232] FIG. 68 , Hold the Releaser Button 31 at this condition and open the Cylinder 20 .
[0233] If your revolver is loaded, push the Extractor Rod 7 to unload your revolver FIG. 69 .
[0234] Pullout the Yoke Latch Button 11 and hold it FIG. 70 .
[0235] Hold the Yoke Latch Button 11 , pull the Unit of Cylinder to front side and remove it from the Frame FIG. 71 .
[0236] Now you can separate the Unit of Cylinder parts (Yoke 13 , Rotator 17 and Cylinder Cover 20 ) FIG. 72 .
[0237] Unscrew the Extractor Rod 7 counter cloak wise to loosen and release it FIG. 73 .
[0238] When you remove the Extractor 19 and its Rod 7 from Rotator 17 , all internal part and springs (Extractor Spring 8 , Center Pin 10 , Center Pin Spring 9 and Flat Ejector Springs 18 ) would be separate FIG. 74 .
[0239] Push the Pawls Flat Spring 15 inward and release the Pawl 14 and its Flat Spring 15 from the Yoke 13 . You can press it by end of Extractor Rods 7 help, FIG. 75 .
[0240] FIG. 76 , Pull the Yoke Latch Cover 16 outside. Release the Yoke Latch Spring 12 . Rotate the Yoke Latch 11 toward Yoke 13 and pull it outside to separate it from Yoke 13 .
[0241] Barrel 6 and Barrel Shroud 2 are locked by Barrel Latch 23 in its position FIGS. 77 & 78
[0242] Push down the Barrel Latch 23 and keep it at this condition FIG. 79 .
[0243] Pull out the Barrel Shroud 2 from the Frame FIG. 80 .
[0244] Turn the Barrel 6 clock wise and pull it out FIGS. 81 & 82 .
[0245] FIG. 83 , By pull out the Cover of Barrel Latch 22 , you can remove the Barrel Latch 23 and its Spring 24 from the Body 21 .
[0246] Press the Front Sight 1 inward and remove it from Barrel Shroud 2 , FIG. 84 .
[0247] Turn out the Seesaw Cover 3 and separate Locking Bolt 5 and its Spring 4 from Barrel Shroud 2 , FIG. 85 .
[0248] FIG. 86 , Pull out the Grip Cover 56 .
[0249] FIG. 87 , By turn the Grip Latch Lever 52 to back side against its Spring 54 , Grip Latches 53 & 55 release the Grip 57 . Hold the Lever 52 at this condition and pull the Grip 57 out
[0250] FIGS. 88 & 89 , you can remove the Frame Cover 49 , then release the Grip Latch Lever 52 , Grip Latches 53 & 55 , Grip Latch Spring 54 , Strain Lever 51 and its Flat Spring 50 .
[0251] Pull out the Sliding Side Plate 26 and then remove the Trigger Cover 48 , FIG. 90 .
[0252] Release the Hammer 36 and Main Spring 35 from the Frame 21 , FIG. 91 .
[0253] By pulling the Stirrup Pin 39 out, you can separate Hammer 36 , Stirrup 40 and Main Spring 35 , FIG. 92 . By push back the end of Torsion Springs 38 , release the Sear 37 from Hammer 36 . You can press it by help of the Main Springs end, FIG. 92 .
[0254] First remove the Trigger 47 , Piston 43 and Internal Cylinder 41 , then release the Bolt 31 from Frame, FIG. 93 .
[0255] FIG. 94 , Pull the Trigger 47 and Connecting Rod 46 toward yourself and pull it down. Turn the Connecting Rod 46 to front side and remove the Trigger 47 . Separate the Internal Cylinder 41 , Piston Spring 42 and Piston 43 . Piston 43 has the two pieces. When you separate these two pieces, you can release the Transfer Pin 44 and its Torsion Spring 45 from Piston 43 . Remove Bolt Spring 32 from the Bolt 31 .
[0256] FIG. 95 , Pull out the Lock System 34 , hold it and remove the Safety Lever 27 from the Frame. Now you can release the Lock System 34 and its Flat Spring 33 completely.
[0257] FIG. 96 , Remove the Firing Pin Cover 30 . Release the Firing Pin 28 and Firing Pin Spring 29 from the Frame.
[0258] FIG. 97 , Push back the Rear Sight 25 and release it. Frame is drilled and tapped for the scope mounts.
[0259] To reassemble of revolver do the reverse direction.
Adjust the Trigger
[0260] You can adjust amount of the pressure on the trigger and set it up for the best use. It's simple and possible without any kind of the tools.
[0261] Move the Grip Cover 56 from its position FIG. 86 .
[0262] Pull the Grip Latch Lever 52 to the back side, keep it at this situation and move out the Grip 57 , FIG. 87 .
[0263] FIG. 98 , Now you have access to the Strain Lever 51 . There is the five adjustment point for this lever on its Flat Spring 50 . By rotate up the Lever 51 you decrease the pressure of Main Spring 35 and Trigger 47 . By move down the Lever 51 you can increase the pressure of Main Spring 35 and Trigger 47 . You must put the lever exactly at the setting points.
[0264] FIG. 99 , If you have access to slotted or cross slotted head screwdriver, you can do it without remove of the grip. Screw head shape of Strain Lever 51 is accessible from right side of the gun. By rotate up and rotate down the Lever 51 , same as open condition of the gun you can adjust pressure of the trigger. Special shape of Flat Spring 50 , helps you to put the Lever 51 at the setting points. You can feel it because pressure of Flat Spring 50 decreased at the adjust points.
|
This design relates generally to firearms and more particularly is a hammerless revolver with ejector system, to replace the hand ejecting system in usual revolvers. External shape of this revolver designed according to ergonomic facts. Internal components and mechanisms are totally new and specially designed for this revolver. Simplify in internal parts plus new kind of safety systems and a manual safety lever make this revolver, durable, safe and easy to repair. To decrease the manufacturing costs there is not screw in the parts of this revolver and most of spiral springs are common. Disassemble and reassemble of this revolver is possible without tools or wrenches. This is next generation of revolver guns.
| 5
|
FIELD OF THE INVENTION
[0001] The invention relates to the pharmaceutical field, concretely to the combined use of 2 active principles, pterostilbene and quercetin, in the manufacture of medicinal products that can be used for cancer treatment.
STATE OF THE ART
[0002] Various phenolic compounds, including resveratrol (RESV), display powerful antioxidant effects and may have therapeutic applications in diseases related to oxidative stress such as cancer (1-3). The anticancer activity of RESV was reported for the first time by Jang et al. in 1997 (4). The mechanisms by which RESV exerts its antitumor effects are being actively investigated (3) and may include for example: a) inhibition of ribonucleotide reductase (5), DNA polymerase (6), protein kinase C (7), or cyclooxygenase-2 (8) activities; b) inhibition of carcinogenesis mediated by reactive species of oxygen (4) or of cellular proliferation (9); and c) activation of cell death by apoptosis (10-13). However, the RESV-mediated potential inhibition of cancer growth is severely limited owing to its low bioavailability (14). Consequently, it appears that structural changes are necessary in the RESV molecule in order to increase its bioavailability while preserving its biological activity. The OH of 4′ and the stereoisomerism in its trans conformation are absolutely necessary for inhibition of cellular proliferation (15). Pterostilbene (PTER), a naturally occurring analog, of RESV but approximately 60-100 times more powerful as an antifungal agent, exhibits similar anticancer properties (16). Furthermore, the flavonoids are some of the most powerful antioxidants because they have one or more of the following structural elements: an o-diphenolic group, a double bond at 2-3 conjugated with the 4-oxo function, OH groups in positions 3 and 5. Quercetin (QUER) combines these three properties, and previous studies have confirmed that it also has antitumor properties, probably due to immune stimulation, elimination of free radicals, alteration of the mitotic cycle of the tumor cells, modification of gene expression, antiangiogenic activity, or induction of apoptosis, or a combination of these effects (2, 17). Concretely, QUER has been described (US 2003/0054357) in the treatment of prostate cancer. There are patents (WO02/34262) which highlight the antioxidant effect of certain flavonoids, concretely of a combination of quercetin plus catechin for use in the treatment and prevention of circulatory or cardiac disorders, by preventing platelet aggregation.
[0003] However, since it has not been demonstrated that the potential anticancer effects are effective in systemic administration, we investigated the anticancer properties of combined systemic administration of PTER and QUER at bioavailable concentrations. We found that their combination strongly inhibits the growth of the metastatic malignant melanoma B16-F10 (B16M-F10).
[0004] Abbreviations: B16M-F10, melanoma B16-F10; RESV, resveratrol; t-RESV, trans-resveratrol; PTER, pterostilbene; t-PTER, trans-pterostilbene; QUER, quercetin; HSE, hepatic sinusoidal endothelium; VCAM-1, vascular cell adhesion molecule 1; VLA-4, very late activation antigen 4; B16M-F10/Tet-Bcl-2, melanoma B16-F10 that overexpresses Bcl-2; LC-MS/MS, high-performance liquid chromatography and mass spectrometry; i.v., intravenous/intravenously; i.p., intraperitoneal; SD, standard deviation.
REFERENCES
[0005] [1] Yang C S, Landau J M, Huang M T, and Newmark H L (2001). Inhibition of carcinogenesis by dietary polyphenolic compounds. Annu Rev Nutr 21, 381-406.
[0006] [2] Ross J A, and Kasum C M (2002). Dietary flavonoids: bioavailability, metabolic effects, and safety. Annu Rev Nutr 22, 19-34.
[0007] [3] Pervaiz S (2003). Resveratrol: from grapevines to mammalian biology. FASEB J 17, 1975-1985.
[0008] [4] Jang M, Cai L, Udeani G O, Slowing K V, Thomas C F, Beecher C W, Fong H H, Farnsworth N R, Kinghorn A D, Mehta R G, et al. (1997). Cancer chemopreventive activity of resveratrol, a natural product derived from grapes. Science 275, 218-220.
[0009] [5] Fontecave M, Lepoivre M, Elleingand E, Gerez C, and Guittet O (1998). Resveratrol, a remarkable inhibitor of ribonucleotide reductase. FEBS Lett 421, 277-279.
[0010] [6] Sun N J, Woo S H, Cassady J M, and Snapka R M (2003). DNA polymerase and topoisomerase II inhibitors from Psoralea corylifolia. J Nat Prod 66, 734.
[0011] [7] Stewart J R, Ward N E, Ioannides C G, and O'Brian C A (1999). Resveratrol preferentially inhibits protein kinase C-catalyzed phosphorylation of a cofactor-independent, arginine-rich protein substrate by a novel mechanism. Biochemistry 38, 13244-13251.
[0012] [8] Subbaramaiah K, Chung W J, Michaluart P, Telang N, Tanabe T, Inoue H, Jang M, Pezzuto J M, and Dannenberg A J (1998). Resveratrol inhibits cyclooxygenase-2 transcription and activity in phorbol ester-treated human mammary epithelial cells. J Biol Chem 273, 21875-21882.
[0013] [9] Sauer H, Wartenberg M, and Hescheler J (2001). Reactive oxygen species as intracellular messengers during cell growth and differentiation. Cell Physiol Biochem 11, 173-186.
[0014] [10] Clement M V, Hirpara J L, Chawdhury S H, and Pervaiz S (1998). Chemopreventive agent resveratrol, a natural product derived from grapes, triggers CD95 signaling-dependent apoptosis in human tumor cells. Blood 92, 996-1002.
[0015] [11] She Q B, Bode A M, Ma W Y, Chen N Y, and Dong Z (2001). Resveratrol-induced activation of p53 and apoptosis is mediated by extracellular-signal-regulated protein kinases and p38 kinase. Cancer Res 61, 1604-1610.
[0016] [12] Tinhofer I, Bernhard D, Senfter M, Anether G, Loeffler M, Kroemer G, Kofler R, Csordas A, and Greil R (2001). Resveratrol, a tumor-suppressive compound from grapes, induces apoptosis via a novel mitochondrial pathway controlled by Bcl-2. FASEB J 15, 1613-1615.
[0017] [13] Scarlatti F, Sala G, Somenzi G, Signorelli P, Sacchi N, and Ghidoni R (2003). Resveratrol induces growth inhibition and apoptosis in metastatic breast cancer cells via de novo ceramide signaling. FASEB J 17, 2339-2341.
[0018] [14] Asensi M, Medina I, Ortega A, Carretero J, Bano M C, Obrador E, and Estrela J M (2002). Inhibition of cancer growth by resveratrol is related to its low bioavailability. Free Radic Biol Med 33, 387-398.
[0019] [15] Stivala L A, Savio M, Carafoli F, Perucca P, Bianchi L, Maga G, Forti L, Pagnoni U M, Albini A, Prosperi E, et al. (2001). Specific structural determinants are responsibie for the antioxidant activity and the cell cycle effects of resveratrol. J Biol Chem 276, 22586-22594.
[0020] [16] Rimando A M, Cuendet M, Desmarchelier C, Mehta R G, Pezzuto J M, and Duke S O (2002). Cancer chemopreventive and antioxidant activities of pterostilbene, a naturally occurring analogue of resveratrol. J Agric Food Chem 50, 3453-3457.
[0021] [17] Lamson D W, and Brignall M S (2000). Antioxidants and cancer, part 3: quercetin. Altern Med Rev 5, 196-208.
[0022] [18] Tuck K L, Tan H W, and Hayball P J (2000). A simple procedure for the deuteration of phenols. Journal of Labelled Compounds and Radiopharmaceuticals 43, 817-823.
[0023] [19] Navarro J, Obrador E, Pellicer J A, Aseni M, Vina J, and Estrela J M (1997). Blood glutathione as an index of radiation-induced oxidative stress in mice and humans. Free Radic Biol Med 22, 1203-1209.
[0024] [20] Carretero J, Obrador E, Esteve J M, Ortega A, Pellicer J A, Sempere F V, and Estrela J M (2001). Tumoricidal activity of endothelial cells. Inhibition of endothelial nitric oxide production abrogates tumor cytotoxicity induced by hepatic sinusoidal endothelium in response to B16 melanoma adhesion in vitro. J Biol Chem 276, 25775-25782.
[0025] [21] Anasagasti M J, Martin J J, Mendoza L, Obrador E, Estrela J M, McCuskey R S, and Vidal-Vanaclocha F (1998). Glutathione protects metastatic melanoma cells against oxidative stress in the murine hepatic microvasculature. Hepatology 27, 1249-1256.
[0026] [22] Carretero J, Obrador E, Anasagasti M J, Martin J J, Vidal-Vanaclocha F, and Estrela J M (1999). Growth-associated changes in glutathione content correlate with liver metastatic activity of B16 melanoma cells. Clin Exp Metastasis 17, 567-574.
[0027] [23] Ohigashi H, Shinkai K, Mukai M, Ishikawa O, Imaoka S, Iwanaga T, and Akedo H (1989). In vitro invasion of endothelial cell monolayer by rat ascites hepatoma cells. Jpn J Cancer Res 80, 818-821.
[0028] [24] Braman R S, and Hendrix S A (1989). Nanogram nitrite and nitrate determination in environmental and biological materials by vanadium (III) reduction with chemiluminescence detection. Anal Chem 61, 2715-2718.
[0029] [25] Okahara H, Yagita H, Miyake K, and Okumura K (1994). Involvement of very late activation antigen 4 (VLA-4) and vascular cell adhesion molecule (VCAM-1) in tumor necrosis factor alpha enhancement of experimental metastasis. Cancer Res 54, 3233-3236.
[0030] [26] Obrador E, Carretero J, Esteve J M, Pellicer. J A, Pascual A, Petschen I, and Estrela J M (2001). Glutamine potentiates TNF-alpha-induced tumor cytotoxicity. Free Radic Biol Med 31, 642-650.
[0031] [27] Eissa S, and Seada L S (1998). Quantitation of bcl-2 protein in bladder cancer tissue by enzyme immunoassay: comparison with Western blot and immunohistochemistry. Clin Chem 44, 1423-1429.
[0032] [28] Rimm E B, Katan M B, Ascherio A, Stampfer M J, and Willett W C (1996). Relation between intake of flavonoids and risk for coronary heart disease in male health professionals. Ann Intern Med 125, 384-389.
[0033] [29] Day A J, Bao Y, Morgan M R, and Williamson G (2000). Conjugation position of quercetin glucuronides and effect on biological activity. Free Radic Biol Med 29, 1234-1243.
[0034] [30] Goldberg D M, Van J, and Soleas G J (2003). Absorption of three wine-related polyphenols in three different matrices by healthy subjects. Clin Biochem 36, 79-87.
[0035] [31] Off F W, Wang H R, Lafrenie R M, Scherbarth S, and Nance D M (2000). Interactions between cancer cells and the endothelium in metastasis. J Pathol 190, 310-329.
[0036] [32] Burdon R H (1995). Superoxide and hydrogen peroxide in relation to mammalian cell proliferation. Free Radic Biol Med 18, 775-794.
[0037] [33] Fremont L (2000). Biological effects of resveratrol. Life Sci 66, 663-673.
[0038] [34] Bravo L (1998). Polyphenols: chemistry, dietary sources, metabolism, and nutritional significance. Nutr Rev 56, 317-333.
[0039] [35] Walle T (2004). Absorption and metabolism of flavonoids. Free Radic Biol Med 36, 829-837.
[0040] [36] Davies K J (1995). Oxidative stress: the paradox of aerobic life. Biochem Soc Symp 61, 1-31.
DESCRIPTION OF THE INVENTION
[0041] For the purposes of the invention, PTER and QUER are also to be understood as meaning any pharmaceutically acceptable salt, particularly the sulfates of both polyphenols, as well as any other pharmaceutically acceptable derivative, particularly the glucuronides of any of the above-mentioned polyphenols.
[0042] The bioavailability and the biological efficacy in vivo are critical factors that have to be correlated before drawing any conclusion about the potential health benefits of the polyphenols (14, 30, 33, 34). As shown in FIG. 2 , where the effect of t-RESV, t-PTER, or QUER was studied, inhibition of the proliferation of B16M-F10 cells in vitro was more potent in the presence of t-PTER+QUER. The bioavailable concentrations of PTER and QUER, measured in the plasma after oral administration, were unable to inhibit the growth of B16M-F10 cells, even in cases when the concentrations of these polyphenols were constant throughout the culture time, see Example 2. However, the bioavailable concentrations of PTER or QUER, measured in the plasma after i.v. administration (see FIG. 1 ), inhibited tumor growth by up to 56%, even in cases when both polyphenols were only present for 60 minutes in each 24 hours of culture ( FIG. 2 ), without increasing the rate of cell death (cell viability still being >95%, as in the controls, in all cases).
[0043] On the basis of these facts, concerning the differences in bioavailability, and the data shown in FIG. 2 , we selected the combination PTER+QUER for studying its effect on metastatic progression. As shown in Table 3, the effect of t-PTER, QUER, t-RESV, or combinations thereof, on the in-vitro interaction between B16M-F10 cells and the vascular endothelium was investigated. Parallel with the effect on tumor growth ( FIG. 2 ), the combination of PTER plus QUER was the one that displayed the greatest capacity for reducing (by approximately 74%) the formation of tumor colonies in an in-vitro invasion test (Table 3).
[0044] To demonstrate that natural polyphenols such as t-PTER and QUER inhibit the metastatic growth in vivo of a highly malignant tumor and increase the survival of the carrier, we employed daily i.v. administration of high doses (20 mg/kg of body weight administered once daily). However, various possible protocols can be considered at this point. For example, if it proved more effective, and nontoxic to humans, the doses could be increased. Furthermore, our results do not rule out possible benefits from the use of oral administration.
[0045] In fact, t-RESV inhibits the expression of VCAM-1 at very low concentrations (1 μM) (14). Nevertheless, as pointed out by Goldberg et al. (30) and taking into account the metabolism in vivo of these small polyphenols (see for example 34-35), investigations of this nature ought to focus on the benefits of its conjugates (for example glucuronides and sulfates). Moreover, the doses required for inhibiting metastatic growth may depend on the type of cell. Furthermore, the combination t-PTER+QUER might also be useful in other pathologies associated with oxidative stress (for example diabetes, arteriosclerosis, neurodegenerative diseases, or ischaemic heart disease) (36) where the doses required for obtaining benefits might be similar or completely different. In conclusion, our findings highlight the applications of combinations of polyphenols in cancer therapy. Moreover, since the administration of polyphenols can be combined with biotherapy, cytotoxic drugs and/or ionizing radiation, the mechanisms described in the invention may have useful applications for improving therapy against metastatic melanoma and, possibly, against other types of malignant tumors.
DETAILED DESCRIPTION OF THE INVENTION
EXAMPLE 1
Plasma Levels of Pterostilbene and Quercetin Animals and “in-vivo” Administration of Polyphenols
[0046] The mice (C57BL/6J, male, 6-8 weeks) were from Charles River Spain (Barcelona). The procedures and animal care were based on institutional standards and complied with national and international laws and policies (Directive 86/609, OJ L 358. 1 of the Council of the European Community, of 12 Dec. 1987) and the “Guide for the Care and Use of Laboratory Animals” of the National Institutes of Health (NIH, USA) (NIH Publication No. 85-23, 1985). All the animals were fed according to concentrated laboratory diets (Letica, Barcelona, Spain) allowing them free access to food and submitting them to a cycle of 12 hours of light/12 hours of darkness with ambient temperature of 22° C. The experiments were begun at 10.00 a.m. to minimize the effects of diurnal variations.
[0047] For the pharmacokinetic studies and for the daily treatment, the mice were administered i.v. (via the jugular vein, where a permanent catheter had previously been fixed by surgical methods; i.v. administration was carried out slowly for 1 minute), and orally (via stomach tube), 20 mg/kg of t-PTER (dissolved in ethanol 0.5 ml/kg of animal weight) or QUER (dissolved in dimethylsulfoxide:saline, 1:0.5 0.15 ml/kg of weight). In general, the compositions based on a combination of PTER and QUER can contain, as excipients, those stated previously or any others that are pharmaceutically acceptable. The presentation of said compositions can be, non-limitatively, in the form of solids such as tablets, capsules, pellets, pills, etc. and liquid presentations such as drops, syrups, injectables, etc. Moreover, the active principles (PTER and QUER) of the composition can be in their uncombined forms or in the form of pharmaceutically acceptable salts, including esters. The t-PTER was synthesized in our laboratory following standardized reactions of Wittig and Heck (www.orgsyn.org), whereas the QUER was obtained from Sigma Chemical Co. (San Luis, Mo., USA). The 3 H-t-PTER (2.2 Ci/mmol), labeled in the ortho and para positions of the benzene rings, was prepared in our laboratory according to a method similar to that used for the deuteration of phenols (18). 14 C-QUER (50 mCi/mmol), labeled in position 4 of the carbon ring, was obtained from the NCI Radiochemical Carcinogen Repository of Chemsyn Laboratories (Kansas City, Mo., USA). The radioactivity was measured using a Varisette 2700 TR analyzer from Packard. Blood was collected by means of the catheter in 1-ml syringes that contained heparin sodium (0.05 ml of a 5% solution in 6.9% NaCl). The plasma and the erythrocytes were separated as described previously (19).
[0048] Determination of Pterostilbene and Quercetin by Liquid Chromatography and Mass Spectrometry (LC-MS/MS)
[0049] LC-MS/MS was carried out using a Quattro Micro triple quadrupole mass spectrometer (Micromass, Manchester, UK) equipped with an LC-10Advp pump, an SLC-10Avp control system and an SIL-10Advp autoinjector from Shimadzu. The samples were analyzed by reverse-phase high-performance liquid chromatography using a Prodigy ODS column (100×2 mm) from Phenomenex (Torrance, Calif., USA), with a particle size of 3 μm. In all cases, 40 μl was injected into the column. Column temperature was maintained at 25° C. The following gradient system was used, pumped through the column at 0.2 ml/minute (min/% A/% B/% C) (A, methanol; B, 10% acetonitrile and 90% ammonium formate 10 mM pH 3.75; C, ammonium formate 10 mM pH 3.75): 0/5/5/90, 10/5/5/90, 20/5/90/5, 30/100/0/0, 40/5/5/90. The negative ion tandem mass spectra obtained by electrospray were recorded with the electrospray capillary fixed at 3.5 keV and at a temperature of the source block of 120° C. Nitrogen was used as nebulizer gas and drying gas, with flows of 300 and 30 l/h, respectively. Argon at 1.5×10 −3 mbar was used as the collision gas for collision-induced dissociation. A test was carried out based on LC-MS/MS with tracking of multiple reactions using the transitions m/z 255-240 for PTER and 300-151 for QUER, which in both cases represent favorable fragmentation routes for these deprotonated molecules. The calibration curves were obtained using a reference standard of PTER or QUER (0.01-100 μM) and it was found in each case that they were linear with coefficients of correlation >0.99. The limits of detection and quantification of our method were 0.01 μM.
[0050] Depending on dietary habits, the human intake of flavones and flavonols (the commonest flavonoids) is ˜3-70 mg/day, of which between 60 and 70% is QUER [the main sources include tea, wine, berries, apples and onions (28)]. However, there are no reports on estimates for the intake of PTER, which is present for example in extracts from the duramen of P. marsupium, and is employed in ayurvedic medicine for the treatment of diabetes, and in black grapes (although quantitative studies have shown that for every 10 parts of RESV, there are only 1-2 parts of PTER) (16 and references therein). As shown in FIG. 1 , after i.v. administration of 20 mg/kg of t-PTER or QUER to mice (a dose which represents, for a human adult with 70 kg body weight, ˜1000 times the maximum amount of PTER found in one kilogram of black grapes, and ˜20 times the maximum daily intake of QUER), their highest plasma concentrations (˜95 μM of PTER and ˜46 μM of QUER 5 minutes after administration) decreases to ˜1 μM in 120 minutes for QUER and 480 minutes for PTER. Following an identical protocol, previously we found that the highest concentration of QUER in plasma ˜43 μM (5 minutes after i.v. administration to rabbits) falls to ˜1 μM in 60 minutes (14). We calculated a plasma half-life of RESV in the mouse of ˜10.2 minutes (Estrela et al., unpublished data). From the data in FIG. 1 , we calculated a half-life of PTER and QUER of ˜77.9 and 20.1 minutes, respectively (see FIG. 1 ). The levels of PTER and QUER in whole blood of mice were not significantly different from those mentioned previously for the plasma. At least 99% of the PTER measured in plasma or blood was in the trans form.
[0051] For comparison, t-PTER or QUER (20 mg/kg) was also administered orally. A mixture of 3 H-t-PTER (5 μCi/mouse) and t-PTER without labeling or of 14 C-QUER (2 μCi/mouse) and QUER without labeling was administered, for the purpose of differentiating between unchanged free polyphenols and their metabolites/conjugates generated in vivo. In order to calculate the free forms, we effected measurements by LC/MS-MS (see the methodology described previously in this document). After applying the corresponding corrections per dilutions, the radioactivity of the samples that contained only free PTER or QUER was subtracted from the total radioactivity measured in an equivalent sample of plasma. As shown in Table 1, after oral administration the plasma levels of PTER and QUER showed some peaks at 60 and 10 minutes, respectively. However, the total levels of PTER and QUER (unchanged free polyphenols plus their metabolites and conjugated forms) were very different. The total concentration of PTER was >10 μM between 30 and 240 minutes after its administration, whereas the levels of total QUER only remained >1 μM in the first 10 minutes (Table 1). During these periods of time, the free PTER represented a small percentage of the total (15-35%), whereas free QUER (except for the first 5 minutes) was almost undetectable (0.5%) (Table 1).
[0000]
TABLE 1
Plasma levels of pterostilbene and quercetin
after oral administration in mice.
Time
PTER
QUER
(minutes)
(μM)
(% free)
(μM)
(% free)
5
2.9 ± 0.6
67 ± 13
1.6 ± 0.3
22 ± 6
10
6.6 ± 1.8*
50 ± 10
2.3 ± 0.7
<0.5*
30
11.1 ± 3.0*
35 ± 5*
0.6 ± 0.2*
<0.5*
60
18.2 ± 2.7*
17 ± 6*
0.2 ± 0.1*
<0.5*
120
13.3 ± 3.4*
15 ± 3*
0.07 ± 0.01*
<0.5*
240
10.6 ± 1.2*
16 ± 4*
0.05 ± 0.02*
<0.5*
480
7.1 ± 0.8*
14 ± 4*
0.05 ± 0.02*
<0.5*
720
1.6 ± 0.5*
12 ± 2*
0.04 ± 0.01*
<0.5*
1440
n.d.
n.d.
n.d.
n.d.
[0052] The animals were treated with 20 mg/kg of body weight of t-PTER or QUER. A group of 6-7 mice was sacrificed at each time point. Not detectable=n.d. *P<0.01 comparing the data obtained at 10-1440 minutes with the data found 5 minutes after administration of the polyphenol.
[0053] Extravascular Levels of Pterostilbene and Quercetin
[0054] To supplement the pharmacokinetics in plasma/blood, we also evaluated the bioavailability of PTER and QUER in extravascular tissues. As shown in Table 2, after their i.v. administration to mice, the highest content of PTER and QUER in brain, lung, liver and kidney occurred within the first 5 minutes after administration (Table 2). Therefore, it appears that neither of the polyphenols is subject to extravascular accumulation and that their presence in various tissues (Table 2) is parallel in time to their bioavailability in the bloodstream ( FIG. 1 ).
[0000]
TABLE 2
Extravascular levels of pterostilbene and quercetin after intravenous administration in mice.
Time
Brain
Lung
Liver
Kidney
(min)
PTER
QUER
PTER
QUER
PTER
QUER
PTER
QUER
5
5 ± 1
4 ± 1
36 ± 6
15 ± 3
14 ± 4
9 ± 3
3 ± 1
1 ± 0.2
10
2 ± 0.5*
2 ± 0.4*
15 ± 3*
8 ± 2*
7 ± 1*
3 ± 1*
3 ± 0.3
1 ± 0.5
30
n.d.
n.d.
6 ± 1*
2 ± 0.6*
3 ± 0.5*
1 ± 0.2*
2 ± 0.4*
n.d.
60
n.d.
n.d.
2 ± 1*
n.d.
n.d.
n.d.
1 ± 0.3*
n.d.
[0055] The animals were treated with t-PTER or QUER (20 mg/kg, containing 5 μCi of 3 H-t-PTER or 2 μCi 14 C-QUER). A group of 4-5 mice was sacrificed at each time point. Not detectable=n.d. *P<0.01 comparing the data obtained at 10-60 minutes with the data found 5 minutes after administration of the polyphenol.
EXAMPLE 2
Inhibition of the Growth of Melanoma B16 Cells “in vitro” Culture of Tumor Cells
[0056] B16M-F10 cells were cultured in Dulbecco's modified Eagle's medium (DMEM; Gibco Labs., Grand Island, N.Y., USA), pH 7.4, supplemented with 10% fetal serum (Gibco), HEPES 10 mM, NaHCO 3 40 mM, 100 U/ml of penicillin and 100 μg/ml of streptomycin (20).
[0057] The B16M-F10 melanoma, highly aggressive, is a model that is widely used for investigating metastatic spread and tissue invasion (21), and for this reason was chosen for our studies. In the first group of experiments, we studied the effect in vitro of t-PTER+
[0058] QUER on the growth of B16M-F10 cells. To reproduce the conditions in vivo after i.v. administration, we incubated B16M-F10 cells in the presence of t-PTER (40 μM) and/or QUER (20 μM) for a limited period (60 minutes) (this represents a value that approximates to the average of the concentrations of PTER and QUER measured in the plasma during the first hour after i.v. administration of 20 mg/kg of each polyphenol ( FIG. 2 ). For comparison, we also used t-RESV (12 μM; selection of this concentration was based on a similar criterion, see the data cited in ref. 14). The polyphenols were added to the incubation medium every 24 hours and, as mentioned, they were only present for 60 minutes. As shown in FIG. 2 , t-PTER and QUER inhibited the growth of B16M-F10 by 40 and 19%, respectively. However, when both were present the inhibition of growth increased to ˜56%, which suggests an additive effect (in the presence of t-PTER+QUER ˜77.7% of the cells accumulated in G0/G1, whereas ˜13.2% and 9.1% were in phases S and G2/M, respectively; moreover, the controls, which were growing exponentially, displayed a distribution of the cell cycle of ˜58.0% in G0/G1, 22.4% in S and 19.6% in G2/M; n=6 in both cases; cell viability was still >95% in all cases). In our experimental conditions, t-RESV did not have a significant effect on the growth rate of tumor cells ( FIG. 2 ). Furthermore, t-RESV did not significantly affect the percentage inhibition of the growth of B16M-F10 promoted by t-PTER+QUER ( FIG. 2 ).
[0059] Also for comparison, we incubated B16M-F10 cells in the presence of t-PTER+QUER at concentrations representing an approximate average value of the total level of each polyphenol measured in the plasma in the first hour after oral administration (11 μM of PTER and 1 μM of QUER) (see Table 1). Both polyphenols, as free forms, were constantly present in the incubation medium. Although both PTER and QUER undergo metabolic transformations after oral administration, the use of free forms is a valid approach since it is not to be expected that their metabolites/conjugates would display more potent antitumor activity (see for example refs. 29-30). However, in these conditions t-PTER (11 μM) and/or QUER (1 μM) did not have a significant effect on the levels of control of growth of the B16M-F10 cells in vitro (similar levels of control corresponding to those in FIG. 2 ).
[0060] The total levels of free polyphenols added to the incubation medium remained unchanged throughout the culture time, indicating that the cancer cells did not metabolize t-PTER or QUER.
EXAMPLE 3
Interaction between B16 Melanoma Cells and Endothelial Cells “in vitro” Isolation and Culture of Hepatic Sinusoidal Endothelium
[0061] C57BL/6J mice were used (male, 10 to 12 weeks old) from IFFA Credo (L'Arbreole, France). The hepatic sinusoidal endothelium (HSE) was separated and identified as described previously (20). The sinusoidal cells were separated in a gradient of 17.5% metrizamide (w/v). The HSE cultures were established and maintained in pyrogen-free DMEM supplemented as described previously for the B16M-F10 cells. Differential adhesion of the endothelial cells to the collagen matrix and washing permitted complete removal of other types of sinusoidal cells (Kupffer's cells, astrocytes, lymphocytes) from the culture flasks.
[0062] Tests of Adhesion and Cytotoxicity between B16 Melanoma Cells and Endothelial Cells
[0063] The B16M-F10 cells were labeled with 2′,7′-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester (BCECF-AM; Moleculer Probes, Eugene, Oreg., USA) (10 6 cells were incubated for 20 minutes at 37° C. in 1 ml of DMEM buffered with HEPES that contained 50 μg of BCECF-AM and 5 μl of DMSO). After washing, the cells that contained BCECF-AM were resuspended in DMEM buffered with HEPES without phenol red at a concentration of 2.5×10 6 cells/ml and were added (0.2 ml/well) to the endothelial cell culture (seeded 24 hours previously), as well as to wells of plastic and controls previously treated with collagen. The plates were then incubated at 37° C. and, 20 minutes later, the wells were washed three times with fresh medium, and then their fluorescence was read using a Fluoroskan Ascent FL (Labsystems, Manchester, UK). The number of adhering tumor cells was quantified with arbitrary fluorescence units based on the percentage relative to the initial number of B16M-F10 cells added to the HSE culture (20). The damage caused to the B16M-F10 cells during their adhesion in vitro to the HSE was evaluated as described previously (21) using tumor cells labeled with calcein-AM (Molecular Probes, Eugene, Oreg., USA). The integrity of the B16M-F10 cells cultivated on their own was evaluated by exclusion of trypan blue and measuring the lactate dehydrogenase released to the extracellular medium (22). The other reagents used in the tumoral cytotoxicity experiments were from Sigma.
[0064] Cytokines
[0065] Recombinant murine TNF-(2×10 7 U/mg of protein) and recombinant murine interferon-(IFN-; 10 5 U/mg of protein) were obtained from Sigma. The concentrated solutions (5×10 5 U TNF-/ml and 25×10 4 U IFN-/ml) were diluted in sterile saline (0.9% NaCl), adjusted to pH 7.0, and stored at 4° C.
[0066] Test of “in-vitro” Invasion of the Monolayer of Hepatic Endothelial Cells by B16 Melanoma Cells
[0067] The test of invasion of the endothelial cell monolayer by B16M-F10 cells was carried out in accordance with the method of Ohigashi et al. (23) with some modifications. The HSE cells were seeded on culture plates with grids coated with gelatin (1%). When the cells attained confluence, the culture medium was replaced with freshly prepared medium. After 2 hours of incubation, the cultures were washed with DMEM and then the B16M-F10 cells were seeded on the HSE cells, maintaining the culture for 5 days. The invasion capacity of the B16M-F10 cells was measured by counting the number of colonies per 1 cm 2 formed under the HSE monolayer using a phase-contrast microscope.
[0068] Measurement of H 2 O 2 , Nitrite and Nitrate
[0069] The test of production of H 2 O 2 was based on the H 2 O 2 — dependent oxidation of homovanillic acid (3-methoxy-4-hydroxyphenylacetic acid), mediated by radish peroxidase, to give a highly fluorescent dimer (2,2′-dihydroxydiphenyl-5,5′-diacetic acid) (20). For this purpose, the cells were cultivated in the presence of homovanillic acid 100 μM and 1 U of radish peroxidase/ml. A linear relation was obtained between fluorescence (excitation=312 nm and emission=420 nm) and the amount of H 2 O 2 in the range 0.1-12 nmol per 2 ml of test sample.
[0070] The determinations of nitrite and nitrate were performed using the methodology of Braman and Hendrix (24). Briefly, the levels of NO 2 − were determined by chemiluminescence detection of NO in the presence of iodide/acetic acid (which reduces the NO 2 − , but not the NO 3 − , to NO). Total NO x (NO 2 − plus NO 3 − ) was determined by measuring the production of NO in samples submitted to a boiling solution of VCl 3 /HCl (which will reduce both the NO 2 − and the NO 3 − to NO). The levels of NO 3 − were determined by subtracting the value for NO 2 − from the value for NO x . Quantification was effected using a standard curve obtained from known quantities of NO 2 − and NO 3 − .
[0071] Flow Cytometry
[0072] Expression of the intercellular adhesion molecules was analyzed by flow cytometry (25). For this purpose, B16M-F10 cells (1×10 6 ) were incubated for 1 hour at 4° C. with 1 μg of a monoclonal antibody (rat IgG2b type, clone PS/2 from Serotec, Oxford, UK) against the mouse very late activation antigen 4 (VLA-4). The HSE (1×10 6 cells) was incubated with 2 μg of a monoclonal antibody (rat IgG type, kappa, clone M/K-2 from R & D Systems, Minn., USA) against the mouse vascular cellular adhesion molecule 1 (VCAM-1). The B16M-F10 and HSE cells were washed twice with PBS and were then treated, for 1 hour at 4° C., with a goat antibody to rat immunoglobins labeled with fluorescein isothiocyanate (Serotec). After washing twice with PBS, the cells were analyzed using a fluorescence-activated cell separator (FACscan, Becton Dickinson, Sunnyvale, Calif., USA). The proliferation and/or viability of the B16M-F10 and HSE cells were not affected by these monoclonal antibodies (even after adding up to 100 μg of antibody/ml of culture medium) (data not shown).
[0073] In addition to the effect of PTER+QUER on tumor growth, we investigated the antimetastatic potential. The interaction of B16M-F10 and HSE cells was studied in vitro first. On the basis of the results obtained previously, we chose brief periods of exposure (60 minutes) of the metastatic cells to the polyphenols (at the concentrations measured in the plasma after their i.v. administration). Since the interaction of the metastatic cells with the endothelial cells and Kupffer's cells activates the local release of proinflammatory cytokines [promoters of adhesion of cancer cells to the endothelium and of invasion (14, 31)], we investigated the effect of the polyphenols on the adhesion of B16M-F10 cells to the HSE in the presence of TNF- and IFN-—this combination of cytokines induces maximum activation of the HSE (see ref. 20 and the references therein) (Table 3). As described previously, t-RESV inhibits the adhesion of tumor cells to the endothelium (˜47%) without increasing the HSE-induced cytotoxicity on the metastatic cells (14). A similar effect (˜60% inhibition of adhesion) was found in the presence of t-PTER (Table 3). In contrast, QUER increased the death of B16M-F10 cells induced by the HSE (˜48%) but without affecting the level of adhesion (Table 3). As shown in Table 3, by combining t-PTER+QUER we obtained the lowest percentage adhesion of B16M-F10 cells to the HSE and the highest percentage cytotoxicity in the adhering cancer cells. On testing the invasion in vitro of monolayers of hepatic endothelial cells by B16M-F10 cells, we found a marked decrease (˜74%) in the number of colonies formed in the presence of t-PTER and QUER (Table 3).
[0000]
TABLE 3
Effect of brief exposure to resveratrol, pterostilbene
and/or quercetin on the interaction in vitro between
B16M-F10 cells and the vascular endothelium.
Number of
Tumor cells
colonies
Adhesion
Cytotoxicity
penetrated
Additions
(%)
(% of adhering
per cm 2
None
100 ± 15
15 ± 2
157 ± 17
RESV
53 ± 7**
12 ± 3
104 ± 12**
PTER
40 ± 6**
19 ± 3*
89 ± 9**
QUER
98 ± 11
52 ± 6**
106 ± 15**
RESV + PTER
32 ± 4**
17 ± 4
77 ± 8**
RESV + QUER
55 ± 7**
55 ± 7**
70 ± 7**
PTER + QUER
37 ± 5**
54 ± 5**
41 ± 5**
[0074] HSE cells, previously cultured for 24 hours [±polyphenol(s), added 12 hours from seeding and removed by washing 60 minutes later], were cocultured with B16M-F10 cells previously cultured for 72 hours [±polyphenol(s), as in FIG. 2 ]. Cytokines [100 units of TNF-/ml and 50 units of IFN-/ml, see (20)] or the vehicle (physiological saline) were added to the culture media 12 hours before starting the cocultures. The proportion of adhesion of the tumor cells to the HSE was ˜1:1 in the cultures treated with cytokines in the absence of polyphenols (this value was assigned an adhesion level of 100%). In the experiments of adhesion between B16M-F10 cells and endothelial cells, 20 minutes after adding the B16M-F10 to the HSE, the plates were washed in the manner described in the methodology. In the tests of endothelium-induced cytotoxicity on the B16M-F10 cells, the tumor damage (expressed as the percentage of tumor cells that lost viability during the incubation period of 4-6 hours, see the methodology) was determined after 6 hours of incubation. During the 6-hour incubation period, the percentage viability of the HSE cells was 99-100% in all cases. All of the tests were carried out in the absence or in the presence of t-RESV (12 μM), t-PTER (40 μM), and/or QUER (20 μM). The values represent mean values±SD from 5-6 different experiments in each case. *P<0.05, **p<0.01 comparing the incubations in the presence and in the absence of polyphenol(s).
[0075] The adhesion of B16M-F10 cells to the HSE induces the release of NO and H 2 O 2 from the endothelium, causing partial death of the metastatic cells (20). We had previously observed that H 2 O 2 was not cytotoxic in the absence of NO, however, the NO-induced tumoral cytotoxicity was increased by H 2 O 2 owing to the formation of potent oxidants such as − H and − ONOO radicals by a process that is dependent on metal ions (20). During the interaction of B16M-F10 and HSE in the presence of t-PTER and QUER (both present x 60 minutes as in Table 3), the NO x that had accumulated in the culture medium during a period of 3 hours was not significantly different from that of the controls (7.5±1.3 nmol/10 6 cells; n=6). In contrast, t-PTER and QUER lowered the production of H 2 O 2 from 70±12 nmol/10 6 cells (controls) to 34±10 nmol/10 6 cells (n=5-6 in both cases, P>0.01). It is inferred from this that the antioxidizing potential of these polyphenols should contribute, at least partially, to checking the cytotoxicity induced by the HSE on the B16M-F10 cells. Although, obviously, other mechanisms activated by t-PTER and/or QUER are promoting the decrease in metastatic activity (Table 3). In this sense, since H 2 O 2 can act as a growth-promoting intracellular messenger (32), at least partially, the inhibition of tumor growth induced by t-PTER and QUER ( FIG. 2 ) might be explained by a decrease of H 2 O 2 — dependent intracellular signals.
EXAMPLE 4
Growth of Metastases in the Liver RT-PCR and Detection of mRNA Expression
[0076] Total RNA was isolated with Trizol (Invitrogen, San Diego, Calif., USA). The cDNA was obtained using a hexamer and the MultiScribe inverse transcriptase kit, following the manufacturer's instructions (TaqMan RT Reagents, Applied Biosystems, Foster City, Calif., USA). Quantitative PCR was carried out using AmpliTaq Gold DNA polymerase (Applied Biosystems) with specific primers: SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15 and SEQ ID NO: 16.
[0077] Quantification of the transcription of each mRNA was carried out with SYBR Green I and an iCycler detection system (Biorad, Hercules, Calif., USA), relating it to the mRNA of glyceraldehyde-3P-dehydrogenase (GAPDH). The target cDNAs were amplified in separate tubes using the following conditions: 10 minutes at 95° C., 40 cycles of amplification (denaturing at 95° C. for 30 seconds; pairing and extension at 60° C. for 1 minute per cycle). The increase in fluorescence was measured in real time during the extension stage. The threshold cycle (C T ) was determined, and then the expression relative to the gene was calculated as: change of expression=2 −(C T ) , where C T =C T target−C T GAPCH, and (C T )=C T treated−C T control.
[0078] Transfer and Analysis of the bcl-2 Gene
[0079] The Tet-off gene expression system (Clontech, Palo Alto, Calif., USA) was used for inserting the mouse bcl-2 gene and transfecting the B16M-F10 cells, as described previously (26) and following the manufacturer's instructions. The protein Bcl-2 was quantified in the soluble cytosolic fraction by enzyme immunoassay (27) using a test based on a monoclonal antibody from Sigma (San Luis, Mo., USA) (a Bcl-2 unit was defined as the amount of Bcl-2 protein in 1000 non-transfected B16M-F10 cells).
[0080] Experimental Metastases
[0081] Hepatic metastases were induced by i.v. inoculations (portal vein), in anesthetized mice (Nembutal, 50 mg/kg i.p.), of 4×10 5 viable B16M-F10 cells suspended in 0.2 ml of DMEM. The mice were sacrificed by cervical dislocation 10 days after inoculation. The livers were fixed by immersion for 24 hours at 22° C. in 10% formaldehyde in PBS (pH 7.4), and were subsequently embedded in paraffin. The density of metastases (average number of foci/100 mm 3 of liver detected in fifteen sections of 10×10 mm 2 per liver) and the volume of metastases (average percentage of liver volume occupied by metastases) were determined as described previously (22).
[0082] Presentation of the Results and Statistical Significance
[0083] The data are presented as mean value±SD corresponding to the stated number of different experiments. Statistical analyses were carried out using the Student t-test, and values of P<0.05 were regarded as significant.
[0084] This methodology makes it possible for the effect of PTER and QUER to be studied in vivo. For this purpose, mice were inoculated with B16M-F10 control cells or B16M-F10/Tet-Bcl-2 which overexpressed Bcl-2. Both subgroups of cells were cultivated beforehand in the absence or in the presence of t-PTER and QUER. B16M-F10 cells were cultivated for 72 hours. t-RESV (12 μM), t-PTER (40 μM), and QUER (20 μM) were added at 6, 30 and 54 hours of culture time, and were present in each case for just 60 minutes. Then they were removed from the culture flasks by washing (3 times with PBS) and the medium was renewed. The levels of Bcl-2 in the B16M-F10 control cells and cells treated with Tet-Bcl-2 were 24±5 and 105±14 units/mg of protein, respectively (n=5 in each case, P<0.01). The number of adhering cells shown in the table was calculated at 60 minutes postinjection (no significant differences were found when the measurements were effected at 30, 120, 180, 240 or 360 minutes postinjection, data not shown). The number of intact cells was calculated at 6 hours postinjection. The experimental microscopy data in vivo are mean values±SD corresponding to 4-5 different experiments. The growth of metastases in the liver was evaluated as stated in the corresponding section of the description, and in this case the mice were treated daily (×10 days) with t-PTER and/or QUER (20 mg/kg of body weight) administered i.v. (the data are mean values±SD corresponding to 25 mice per group). A similar method and equal number of mice per group were used for evaluating the survival of the carrier animals. The test of significance relates, in all the groups, to comparison between cases with PTER and/or QUER and cases without additions (*P<0.05 and **P<0.01), and to comparison between the B16M-F10/Tet-Bcl-2 cells with the B16M-F10 control cells ( + P<0.05, ++ P<0.01). As shown in Table 4, t-PTER and QUER lowered the intracellular levels of Bcl-2 and the number of B16M-F10 and B16M-F10/Tet-Bcl-2 cells adhering to the endothelium. However, owing to differences in the level of Bcl-2 between the two cellular subgroups, t-PTER and QUER only lowered the percentage of adhering and intact cells in the case of the B16M-F10 control cells (Table 4). In consequence, although the untreated mice, which had been inoculated with B16M-F10 or B16M-F10/Tet-Bcl-2 cells, displayed similar levels of metastatic growth in the liver and a similar survival of the host, the effect of daily i.v. administration of t-PTER and QUER was more evident in the B16M-F10 control cells: 74% decrease in the density and volume of metastases and a doubling of the survival of the carrier host (Table 4). This is the first time that the combined administration in vivo of natural polyphenols has induced inhibition of metastatic growth of a highly malignant tumor and an increase in the survival of the carrier. As can be seen in the aforementioned Table 4, PTER and QUER, separately, also lower the density and volume of the metastases, but their combination produces a synergistic effect on the tumor greater than 100% if we take as the baseline the respective action of each one separately. Conversely, separately, neither of these compounds significantly increased the survival of the host cells, compared with the doubling of the survival rate observed with the combined action of both polyphenols.
[0000]
TABLE 4
Growth of metastases in the liver of mice after intrasplenic
injection of B16M-F10 cells treated with PTER and QUER
and which contained different levels of Bcl-2.
Melanoma
B16M-F10/ter-
Additions
B16M-F10
Bcl-2
Intracellular
NONE
35 ± 5
160 ± 25 ++
levels of Bcl-
PTER
21 ± 4**
151 ± 18 ++
2 before
QUER
9 ± 3**
125 ± 13* ++
inoculation
PTER + QUER
7 ± 2**
118 ± 16** ++
(units/mg
protein)
Number of
NONE
45 ± 7
42 ± 6
cells adhering
PTER
20 ± 5**
21 ± 4**
to the HSE
QUER
46 ± 9
40 ± 7
(average
PTER + QUER
18 ± 4**
17 ± 3**
number per
lobe)
Intact cells
NONE
83 ± 14
85 ± 13
(percentage of
PTER
85 ± 17
91 ± 20
cells adhering
QUER
52 ± 8**
87 ± 13 ++
to the HSE)
PTER + QUER
48 ± 10**
90 ± 17 ++
Density of
NONE
27 ± 5
29 ± 5
metastases
PTER
18 ± 4**
15 ± 3**
(number of
QUER
15 ± 4**
26 ± 516 ++
foci/100 mm 3 )
PTER + QUER
7 ± 2**
20 ± 4* ++
Volume of
NONE
22 ± 4
25 ± 6
metastases
PTER
14 ± 4**
15 ± 3**
(percentage of
QUER
12 ± 3**
24 ± 5 ++
liver volume)
PTER + QUER
6 ± 2**
19 ± 5 ++
Survival of
NONE
13 ± 2
12 ± 1
the carrier
PTER
15 ± 2
12 ± 2
(days)
QUER
15 ± 1
13 ± 2
PTER + QUER
27 ± 3**
14 ± 2**
DESCRIPTION OF DRAWINGS
[0085] FIG. 1 . Plasma levels and half-life of pterostilbene and quercetin after intravenous administration in mice. The animals were treated with t-PTER (empty circles) or QUER (filled circles) (20 mg/kg of body weight). The plasma levels were determined as explained in the description. The results are mean values±SD corresponding to 5-6 mice at each time point, measured in minutes (abscissa). In the box, the same is shown on a logarithmic scale.
[0086] FIG. 2 . Inhibition in vitro of the growth of B16M-F10 cells by brief exposure to resveratrol (RESV), pterostilbene (PTER) and/or quercetin (QUER). All the points are mean values±SD corresponding to 5-6 independent experiments. *P<0.05, **P<0.01 compared with the control values.
|
The invention relates to the combined use of pterostilbene and quercetin for the production of cancer treatment medicaments. The in vitro growth of melanoma cells B16-F10 (B16M-F10) is inhibited (56%) by combined exposures of short duration (60 min/day) to PTER (40 μM)+QUER (20 μM) (˜average values of plasma concentrations measured within the first hour following the IV administration of 20 mg of each polyphenol/kg ˜). The combined intravenous administration of PTER+QUER (20 mg/kg×day) to mice inhibits (73%) the metastatic growth of melanoma B16M-F10 in the liver, a common site for metastasis development. The invention demonstrates that the combination of PTER+QUER inhibits the growth of malignant melanoma metastasis and prolongs the survival of the carrier host.
| 0
|
BACKGROUND
The invention relates to a separator for mechanically separating an actuator and an operating mechanism which is adapted to be displaced by said actuator. Examples of actuators and operating mechanisms of the type in question have been described e.g. in DE 202 13 391, WO 2008/125136 of the present applicant. The actuator in question is normally driven electrically by one or a plurality of motors and displaces an operating element of the operating mechanism. Such an operating mechanism is e.g. a choke, a valve, a BOP (blow-out preventer) or the like. Such operating mechanisms are used in the field of oil or natural gas drilling/production.
In the case of such known units comprising actuators and operating mechanisms, safety measures have already been taken so as to displace e.g. the operating mechanism to a safe position if the actuator should fail.
All the hitherto known safety measures are, however, comparatively complicated from the structural point of view and must additionally be installed in particular in the operating mechanism or in the actuator.
SUMMARY
It is the object of the present invention to allow the actuator and the operating mechanism to be mechanically separated by a suitable separator in a simple way, without such a separator leading to any structural modifications or enlargements of the actuator and/or the operating mechanism. In addition, the separator according to the present invention should be operable easily, in particular by an external user, and allow predetermined displacement of the operating mechanism.
According to the present invention, the separator is arranged between the actuator and the operating mechanism. This has the effect that structural modifications of the actuator and of the operating mechanism can be dispensed with. The separator according to the present invention comprises a driving mechanism. For example, the driving mechanism can be a clutch with first and second clutch components. The first clutch component is associated with the actuator and the second clutch component is associated with the operating mechanism. By displacing the clutch components from a clutch engagement position to a clutch release position, the driving connection between the actuator and the operating mechanism is separated. This displacement to the release position simultaneously enables the operating mechanism to assume a safe position, which, especially in the case of oil or natural gas production, is necessary for avoiding e.g. an unintentional escape of oil or gas.
In order to be easily able to move the clutch components relative to one another, at least one of the components of the driving mechanism is provided with an application part. In order to be able to displace this application part and, consequently, the component connected thereto, the application part is adapted to be brought into releasable engagement with an external displacement part which is suitable for handling by a user.
It is thus possible to separate the operating mechanism from the actuator and to shift it to a safe position even if the actuator should fail to operate or operate incorrectly.
In order to allow easy engagement of the application part and of the displacement part, the application part may be pin-shaped.
According to another embodiment, the application part can be an annular ring, which projects, in particular in the radial direction, at least at certain locations.
In order to allow an adequate engagement with the application part in both cases, the displacement part may be provided with at least one reception slot for the application part. This reception slot has inserted therein e.g. the pin-shaped application part, which can then be displaced in an adequate manner by moving the displacement part so as to shift e.g. the separator to a release position.
In order to allow the application part to be inserted into the displacement part more easily, the reception slot can in this respect be provided with an opening which widens towards the application part. The reception slot and the application part can thus be associated more easily.
This will be of advantage in particular for an external user, which may also be an ROV (Remote Operated Vehicle) or the like.
When a pin-shaped application part and an application ring are compared with one another, it turns out that they differ insofar as a pin-shaped application part should normally be arranged on the respective driving mechanism component such that it is secured against rotation relative thereto, so as to allow a reliable engagement with the displacement part. Such an engagement that prevents relative rotation will normally not be necessary in the case of an application ring.
Furthermore, it should be pointed out that neither a hydraulic nor a electric supply is necessary according to the present invention, since the separator carries out a mechanical separation by means of the external user.
According to another embodiment, the displacement part can be a rotatable displacement cylinder. This displacement cylinder includes it its circumferential surface the reception slot, which may e.g. be helical in shape. By rotating the displacement cylinder in an adequate manner, also the application part will be displaced and, consequently, the mechanical separation will be carried out by means of the separator. The displacement cylinder can in this respect be arranged outside of and in closely spaced relationship with the application part so that an adequate engagement and cooperation of these two components is possible.
It is also imaginable that the displacement cylinder surrounds the application part, so that the latter engages, from the interior of the displacement cylinder, a complementary groove as a reception slot.
Also in the case of these two embodiments, the respective reception slot can be adapted to be brought into engagement with the application part via an extended opening.
When the displacement part has been used as intended, it can be removed from the external user and e.g. be carried along by said external user.
In order to allow the respective driving mechanism components to be produced easily and such that a reliable engagement can be established, if a clutch is used, the first and second clutch components can be implemented as clutch sleeves which are adapted to be inserted into one another. When the respective clutch sleeves have been inserted into one another, e.g. the clutch engagement position is realized, whereas the clutch release position is realized when the clutch sleeves are separated at least partially or drawn apart partially.
In order to allow each of the clutch sleeves to be associated with and releasably connected to the actuator and the operating mechanism, respectively, each clutch sleeve may comprise a sleeve bottom and a sleeve reception opening located opposite to said sleeve bottom. The sleeve bottom serves e.g. for fastening the respective clutch sleeve to a part of the actuator or of the operating mechanism. The respective parts of the actuator and of the operating mechanism are, when no separator is provided, directly connected to one another so as to allow through this connection a displacement of the operating mechanism through the actuator.
The sleeve reception openings of the clutch sleeves serve to insert the respective clutch sleeves into one another until the clutch engagement position has been reached.
In order to simplify the connection of the two clutch sleeves in the clutch engagement position as well as the connection to the actuator or the operating mechanism, the separator may additionally comprise a clutch push rod. This clutch push rod is arranged in the interior of the clutch sleeves and connected to e.g. a respective actuator element of the actuator.
In order to easily realize the engagement position and also the release position, one of said clutch sleeves may be provided with a conically narrowing portion, said conically narrowing portion being in contact with an edge portion of the other clutch sleeve in the engagement position. Due to this contact, the two clutch sleeves are coupled to one another so that a rotary movement of the actuator can be transmitted to the operating mechanism via the coupled clutch components. The release position is in this respect established by eliminating the contact between the edge portion and the conically narrowing portion.
In order to support in this respect the contact between the edge portion and the conically narrowing portion, the edge portion may have, on the inner side thereof, a projection which protrudes radially inwards and which is adapted to be brought into supporting engagement with a complementary circumferential groove of the clutch push rod. This engagement is established in particular in the engagement position.
It is possible to move only one driving mechanism component and to realize thus the engagement position or the release position. Furthermore, it is possible that respective application parts protrude from each component, so that each component can be displaced separately by means of a respective displacement part. In this respect, it should be taken into account that it is also possible to establish the engagement position by only displacing one component by an application part, whereas the displacement of the other application part on the other component has the effect that e.g. the operating mechanism will be displaced to a specific position.
By adequately arranging and implementing the application part and the displacement part, further variations of displacing each component as well as of displacing the components relative to one another are possible.
It is, for example, possible to establish the release position by means of an application part of a component, whereas, depending on the type of operating mechanism, the operating mechanism can be opened or closed or adjusted in some other way, also variably, by means of displacing the other application part of the other component.
A simple embodiment of such an application part is an annular flange which projects radially outwards, at least at certain locations. This annular flange is arranged on the component or, if the embodiment is a clutch, the clutch sleeve.
It has already been pointed out that the separator can be arranged between the actuator and the operating mechanism. In order to easily allow this mode of arrangement also in the case of different types of operating mechanisms and actuators on the basis of a small number of structural modifications, the separator may be configured in particular as a retrofittable module. When no separator is provided, the actuator and the associated operating mechanism are in direct contact with one another so as to interconnect the respective elements.
In the area of this connection, the separator is then arranged in the form of a module, so that the connection between the actuator and the operating mechanism can be separated externally and mechanically. In this respect, it may suffice when, depending on the respective operating mechanism used, e.g. only the displacement part is configured such that it allows, on the basis of a variable structural design of the respective reception slot or of the displacement portion, cf. the embodiments following hereinbelow, a displacement of the operating mechanism to a safe starting position.
This means that respective different displacement parts can be used for each of the choke, valve, BOP or the like.
In view of the fact that, in the field of maritime oil or natural gas production, it may be comparatively difficult to bring the displacement part and the application part into suitable engagement with one another, the separator may comprise a guide unit for the displacement part. Normally, such a guide unit will work such that will guide the displacement part already before the latter comes into contact with the application part and guide said displacement part accurately to the application part in a reproducible manner.
The use of such a guide unit provides a higher mechanical load capacity, which may otherwise perhaps not be given to a sufficient extent during a first direct contact between the application part and the displacement part.
It is imaginable that the guide unit guides the displacement part directly to the application part. An indirect guidance is, however, imaginable as well, by providing the displacement part with at least one guide element for engagement with the guide unit. This has the effect that the guidance and the influence which the displacement part has on the application part are separated from one another.
In order to realize a comparatively simple guide unit, the latter may comprise one or a plurality of generally C-shaped, slotted guide sleeves for guiding generally rod-shaped guide elements.
The C-shape of the guide sleeves will be of advantage in particular in cases where e.g. two guide elements have arranged between them a displacement plate as a displacement part. This displacement plate extends through the slots in the C-shaped guide sleeves and is provided with at least one displacement portion projecting in the direction of the application part. Guided by the guide elements in the guide sleeves, this displacement portion comes into contact with the application part and allows an adequate displacement of said application part.
In order to allow in the case of a simple linear movement of the displacement portion as a displacement part an adequate displacement of the application part transversely to this linear direction, the displacement portion can be delimited by at least one displacement bevel. The displacement portion comes into contact with the application part via its displacement bevel and, in response to a further linear displacement of the displacement portion, the displacement bevel pushes the application part in an adequate direction.
In order to improve guidance in this respect and in order to make it mechanically more stable, guide elements can be releasably fastened to upper and lower narrow sides of the displacement plate. Accordingly, the guide unit is provided with associated guide sleeves.
In order to simplify the handling of the displacement part by an external user, the displacement part may be provided with a handling end portion, the displacement plate being laterally fastened to said handling end portion in a releasable manner. It is also possible to fasten displacement plates on both sides of the handling end portion. Such a handling end portion is provided with a suitable coupling possibility for an external user, e.g. an ROV or the like.
In order to allow, in combination with sufficient mechanical stability, a certain elasticity of the displacement part, the displacement plate and the handling end portion may be fastened via elastic inserts. Such inserts consist e.g. of an elastic rubber or plastic material and allow a linear guidance or alignment of the guide elements, although a certain flexibility of the guide elements is still given.
Depending on the respective embodiment, the displacement plate may comprise various displacement portions with respective displacement bevels for each clutch component and its application part, or the displacement plate may comprise a displacement portion with two opposed displacement bevels, the first of said displacement bevels cooperating with the application part of the first clutch component and the second one cooperating with the application part of the second clutch component.
In both cases each of the clutch components can be displaced separately and in a variable manner, depending on the structural design of the displacement bevels, by displacing only one displacement part.
As regards the displacement bevels, it should additionally be pointed out that they may have different inclination angles, which, when coming into contact with the application part, influence the displacement of the latter.
Due to adequate guidance and by means of these bevels, the driving mechanism components are positioned such the respective operating element of the operating mechanism will be displaced to a defined position.
In order to support the contact between the application part and the displacement bevel, at least one component can be acted upon by a spring, in particular in the direction of the engagement position.
A mechanically stable and reliable system can be realized by arranging the displacement plates in pairs side by side with respective guide elements. These juxtaposed displacement plates are plates of a similar type, but it is also imaginable that one displacement plate displaces the first component and the other displacement plate displaces the second component.
In order to simplify the cooperation of guide sleeves and guide elements, the guide unit or the respective guide sleeve may be provided with a widening reception opening in the direction of the guide element.
The respective displacement plates may preferably also be produced by cutting them out of a plate-shaped steel material, and such cutting may be executed by means of laser, plasma or water jet cutting. In order to avoid marine growth on the respective guide sleeves, in particular when these sleeves are used for maritime purposes, it is additionally possible to insert polyurethane rods or the like into the guide sleeves, when the latter are not in use.
DRAWINGS
In the following advantageous embodiments of the present invention will be explained in more detail on the basis of the enclosed figures of the drawing, in which:
FIG. 1 shows a schematic representation of a separator according to a first embodiment of the invention in a sectional side view;
FIG. 2 shows a top view of the embodiment according to FIG. 1 ;
FIG. 3 shows, in analogy with FIG. 1 , a representation of a second embodiment;
FIG. 4 shows a top view of the second embodiment according to FIG. 3 with a displacement part;
FIG. 5 shows, in analogy with FIG. 1 , a view of a third embodiment;
FIG. 6 shows, in analogy with FIG. 1 , a representation of a fourth embodiment;
FIG. 7 shows a representation of a fifth embodiment according to the present invention in a longitudinal section;
FIG. 8 shows a side view of the embodiment according to FIG. 7 ;
FIG. 9 shows, in analogy with FIG. 7 , a representation of a sixth embodiment;
FIG. 10 shows a cross-sectional view of the embodiment according to FIG. 9 ;
FIGS. 11 to 14 show various relative positions of clutch components according to the present invention;
FIGS. 15 to 17 show various relative positions of the displacement part and the module housing with part of ROV in FIG. 15 ;
FIG. 18 shows a longitudinal section through an embodiment of a displacement part;
FIG. 19 shows a cross-section through the embodiment according to FIG. 18 ;
FIG. 20 shows a rear view of the embodiment according to FIG. 18 ;
FIG. 21 shows a further embodiment of a displacement part;
FIG. 22 shows still another embodiment of a displacement part;
FIG. 23 shows an embodiment of a displacement part with a displacement portion;
FIG. 24 shows an embodiment of a displacement part with two displacement portions; and
FIG. 25 shows, in analogy with FIG. 24 , an embodiment with different displacement bevels of the displacement portions.
DETAILED DESCRIPTION
FIGS. 1 to 6 show schematic diagrams of different embodiments of a separator comprising an application part 6 and a displacement part 7 .
FIGS. 1 and 2 show a first embodiment of a separator in a longitudinal section and in a top view. In the representations according to FIGS. 1 to 6 the actuator and the operating mechanism are not shown, nor are respective parts used for coupling and decoupling shown in these figures.
What is, however, shown is the principle of the present invention.
In particular, an application part 6 is shown, which has essentially the shape of a pin that projects radially outwards from a sleeve. The sleeve is secured to a shaft such that it is secured against rotation relative thereto, said shaft extending between the non-depicted actuator and the operating mechanism. A displacement part 7 comprising a reception slot 11 is adapted to be moved into contact with the application part 6 from outside and externally. The reception slot 11 is open towards the application part and is provided with a reception opening 12 that widens in this direction. The displacement part 7 can be moved by a user, such a user being e.g. an ROV (Remote Operated Vehicle).
When the application part 6 has been arranged in the reception slot 11 , cf. FIG. 2 , the displacement part can be displaced to the left or to the right in FIG. 2 , i.e. in the longitudinal direction of the shaft, whereby the application part 6 will be displaced in this direction. This will cause coupling or decoupling within the separator so that the actuator and the operating mechanism are separated from or connected to one another.
FIGS. 3 and 4 show a second embodiment, which differs from the above embodiment essentially with respect to the shape of the application part 6 . Instead of a pin-shaped application part according to FIGS. 1 and 2 , an application ring 10 is used in FIGS. 3 and 4 , said application ring 10 extending around the respective shaft and projecting radially outwards therefrom. In this case, it is not necessary to connect the application ring or the respective sleeve and the shaft such that they are secured against rotation relative to one another.
Additional embodiments are shown in FIGS. 5 and 6 . In these embodiments, the displacement part is not plate-shaped, as has been the case with the preceding embodiments, but cylindrical, and is thus configured as a displacement cylinder 13 . This displacement cylinder 13 is rotatable about an axis so that, when the rotation takes place, the pin-shaped application part 6 moves along the helical reception slot 11 and is thus displaced in the longitudinal direction of the shaft. The reception slot 11 is arranged in an outer surface of the displacement cylinder 13 and may, if necessary, also extend up to and into the interior of the displacement cylinder 13 .
Such a displacement cylinder 13 with a continuous reception slot 11 is shown in the fourth embodiment according to FIG. 6 . Also in this case, the displacement cylinder 13 is rotated for displacing the application part 6 in the longitudinal direction of the associated shaft. The displacement cylinder 13 surrounds the shaft as well as the application part 6 , which is inserted into the respective reception slot 11 from inside. At least in the embodiment according to FIG. 6 , the reception slot is also provided with respective reception openings 12 at the ends of the reception slot.
In the case of all the embodiments according to FIGS. 1 to 6 , a connection between the actuator and the operating mechanism is separated or influenced mechanically so that the driving connection between these two elements will be interrupted.
For actuating the respective displacement part 7 , it is not necessary to provide any electric or hydraulic supply, but the displacement part 7 is operated mechanically, e.g. by an ROV 55 , see FIG. 15 .
In the above embodiments and also in the embodiments following hereinbelow, it is not necessary to actuate the actuator in its interior or to eliminate the self-holding function in an actuator of the self-locking function type. Instead, a direct separation of the driving connection between the actuator and the operating mechanism is executed and possibly also a displacement of the operating mechanism to a safe starting position. Depending on the operating mechanism used, the safe starting positions may differ from one another. In the case of a valve or a choke, the aimed-at starting position may be a fully closed or a fully open position, or an arbitrary intermediate position.
Further embodiments are shown in the figures following hereinbelow.
FIG. 7 shows a vertical section through a fifth embodiment of a separator of the type in question. This separator is inserted between the actuator 2 and the operating mechanism 3 in the form of a module 28 . The movement connection between the actuator and the operating mechanism extends through the separator 1 , cf. in this respect also the assignment of a first component 4 to the actuator 2 and of a second component 5 to the operating mechanism 3 . In this embodiment the separator driving mechanism is a clutch and both the first component 4 and the second component 5 are clutch components. The second clutch component 5 is connected to a respective operating element of the operating mechanism 3 , a movement connection existing between the first and second clutch components 4 , 5 only in the clutch engagement position 8 , cf. in this respect also FIG. 11 to FIG. 14 . In FIG. 7 , the clutch components are arranged in the clutch engagement position 8 . In the interior of the two clutch components, a clutch push rod 20 is additionally provided. One end of this clutch push rod 20 is releasably connected to a respective operating element of the actuator 2 and serves to transmit, in the clutch engagement position, a rotary motion to the second clutch component 5 and, via said second clutch component 5 , to the respective operating element of the operating mechanism 3 .
The clutch components 4 and 5 and the clutch push rod 20 are arranged within a module housing 29 of the module 28 . This module housing 29 is open in the direction of the displacement part 7 , cf. in this respect also FIGS. 15 to 17 , and, perpendicularly to this direction, it is closed by approximately C-shaped housing walls. These housing walls are releasably connected to the actuator and the operating mechanism, respectively.
On one side of the module housing 29 , a guide unit 30 is provided. This guide unit 30 comprises two guide sleeves 35 and 36 , cf. also FIG. 8 , which are arranged one above the other in spaced relationship with one another. The guide sleeves 35 and 36 have different diameters, said diameters being adapted to the respective diameters of associated guide elements 31 , 32 , cf. FIGS. 15 to 17 . The displacement part 7 and the application part 6 are thus associated with one another in an oriented manner.
In the embodiment according to FIGS. 7 and 8 , two application parts are provided, one application part 6 having the shape of a radially outwardly projecting annular flange 27 protruding from the outer surface of the first clutch component 4 and, analogously thereto, an application part 26 , which also has the shape of an annular flange 27 , protrudes from the second clutch component 5 . The second clutch component 5 comprises in this case a second clutch sleeve 15 and a plate-shaped connection part provided with the respective application part 26 .
In FIG. 7 , various positions of the application part 6 of the first clutch component 4 are shown. In the position of the application part 6 represented by the solid line, the clutch engagement position 8 is realized, whereas in the additional positions of the application part 6 , which are indicated by broken lines, respective clutch release positions 9 are realized, cf. also FIGS. 11 to 14 . At least the first clutch component 4 has pressure applied thereto by a spring element 51 in the direction of the second clutch component 5 .
At the respective clutch engagement position 8 , the clutch components are inserted into one another to such an extent that they are in rotary frictional engagement with one another due to the fact that a conical portion 21 , cf. also FIG. 13 , cooperates with an edge portion 22 as well as due to the fact that this edge portion 22 engages a circumferential groove 25 of the clutch push rod 20 , cf. also FIG. 11 .
In FIG. 8 it can additionally be seen that the respective guide sleeves 35 and 36 are provided with reception openings 52 at one end thereof, said reception openings 52 widening in the direction of the displacement part.
The guide sleeves 35 and 36 are releasably secured to the module housing 29 , cf. also FIG. 10 .
The embodiment according to FIGS. 9 and 10 differs from that according to FIGS. 7 and 8 with respect to the dual arrangement of the guide sleeves 35 and 36 on both sides of the clutch components 4 and 5 .
As for the rest, the embodiment according to FIGS. 9 and 10 corresponds to that according to FIGS. 7 and 8 as regards function and use. In correspondence with FIGS. 9 and 10 , also the associated displacement part 7 is provided with two respective guide elements, cf. the statements made with respect to the figures following hereinbelow.
FIGS. 11 and 14 show various relative positions of the clutch components 4 and 5 , which are configured as first and second clutch sleeves 14 , 15 in the case of all the respective embodiments.
Such a clutch sleeve 14 or 15 each comprises a sleeve bottom 16 , 18 and a sleeve reception opening 17 , 19 , which is open in the direction of the other clutch component. It is thus possible to insert the two clutch sleeves 14 , 15 into one another, cf, e.g. FIG. 11 , 12 or 14 .
FIG. 11 shows the clutch engagement position 8 and FIG. 12 shows the clutch release position 9 . At the clutch release position 9 , the clutch push rod 20 is still connected to the second clutch sleeve 15 . This connection is established in that an annular projection 24 , which is formed on the inner side 23 of the edge portion 22 , is in engagement with a complementary circumferential groove 25 provided in a head on an end of the clutch push rod 20 .
The respective application parts 6 and displacement parts 7 are not shown in FIGS. 11 to 14 for the sake of simplicity. The displacement of the respective clutch sleeves 14 , 15 is, however, based on the cooperation of the application part 6 and the displacement part 7 , as will be described in more detail in the following.
In FIG. 13 , the clutch sleeves are still decoupled, but the clutch push rod 20 and the second clutch sleeve 15 are now separated as well, i.e. the annular projection 24 and the circumferential groove 25 are no longer in engagement with one another.
At this position of the clutch sleeve, the actuator is at an open position and, due to the further displacement of the second clutch sleeve 15 in the direction of the operating mechanism 3 , the latter is at a closed position.
In FIG. 14 , the actuator is at a closed position and, due to the displacement of the second clutch sleeve 15 in the opposite direction in comparison with FIG. 13 , the operating mechanism is at an open position.
FIGS. 15 to 17 show for the embodiments according to FIGS. 7 to 14 a respective cooperation of the displacement part 7 and the associated application parts 6 . In FIG. 15 , the respective displacement part 7 is held by means of its handling end portion 49 by the external user, e.g. an ROV, and is then moved in the direction of the separator 1 .
The displacement part 7 comprises, in addition to a displacement plate 37 , guide elements 31 and 32 provided on the upper and lower ends of said displacement plate 37 . These guide elements 31 and 32 are substantially rod-shaped and are used for insertion into guide sleeves 35 and 36 of the guide unit 30 , cf. also FIG. 16 , The insertion of the guide elements is facilitated by the reception openings 52 of the guide sleeves 35 and 36 , said reception openings 52 widening in the direction of the guide elements.
In FIG. 17 , the displacement part 7 has been inserted into the separator 1 to the highest possible degree.
During insertion, cf. FIGS. 16 and 17 , the displacement plate 37 comes into contact with the respective application part 6 . In the embodiment according to FIGS. 15 to 17 , the displacement plate 37 is substantially composed of two parts, cf, also FIG. 18 , where a first part is defined by a first displacement portion 41 and a second part is defined by a second displacement portion 42 . The different displacement portions come into contact with the different application parts 6 and 26 , respectively. When the displacement part 7 is inserted still further, cf. FIG. 17 , the application parts 6 and 26 slide along respective displacement bevels 43 and 45 of the displacement portions 41 and 42 , and due to this movement, cf. FIGS. 11 to 14 , the clutch sleeves 14 and 15 are raised or lowered in the direction in question
The application part 6 , for example, slides along a respective displacement bevel 43 , cf. also FIGS. 7 and 9 , and the application part 26 slides along the displacement bevel 45 . The raising and lowering of the respective application parts and also the moment at which said raising and lowering takes place result from the length of the displacement portions 41 , 42 and from the inclination angles of the displacement bevels 43 and 45 .
From a comparison between FIGS. 15 to 17 and FIGS. 7 and 9 it can erg. be seen that the application part 6 is raised first, cf. in this respect the final coupling position according to FIG. 12 , and that, a short time after said raising of the application part 6 , the application part 26 is raised analogously by the displacement bevel 45 , cf. e.g. FIG. 14 .
The respective guide elements 31 and 32 are releasably secured to upper and lower narrow sides 47 , 48 of the displacement plate, cf. also FIGS. 18 to 20 . The displacement plate itself is laterally secured to the handling end portion 49 in a releasable manner, cf. FIG. 19 .
FIGS. 18 to 20 show the displacement part 7 according to FIGS. 15 to 17 in detail and in an enlarged representation. There is, however, one difference. The displacement bevel 44 on a lower surface of the respective displacement portion 41 is, in the case of the embodiment according to FIGS. 18 and 20 , slightly inclined to the bottom right in said figures, whereas in the case of the embodiment according to FIGS. 15 to 17 it extends horizontally without any inclination.
Furthermore, the displacement bevel 45 in the embodiment according to FIGS. 18 to 20 extends slightly less steeply than that in the embodiment according to FIGS. 15 to 17 .
It should here be pointed out that a plurality of differently inclined displacement bevels and complementary lengths of the displacement portions are possible and can be selected according to requirements for the actuator and the operating mechanism and the respective separator.
FIG. 18 corresponds to a longitudinal section through the displacement part 7 , FIG. 19 corresponds to a cross-section in the longitudinal direction of the displacement part 7 according to FIG. 18 , and FIG. 20 is a rear view of the displacement part in question.
The displacement part 7 includes the displacement plate 37 which comprises two displacement portions 41 and 42 . The displacement portion 41 has an upper displacement bevel 43 and a lower displacement bevel 44 . The displacement bevel 43 comes into contact with the application part 6 , and the latter moves, in response to a respective movement of the displacement part 7 , along the displacement bevel 43 upwards in FIGS. 7 and 9 .
Due to the gently inclined displacement bevel 45 of the displacement portion 42 and the corresponding displacement bevel 44 of the displacement portion 41 , the application part 26 according to FIGS. 7 and 9 is moved only slightly towards the operating mechanism, so that, at the position of the displacement part 7 according to FIG. 17 , said operating mechanism is essentially still open to approx. 50%. This means that, analogously to FIG. 13 , the application part 26 is moved only slightly towards the operating mechanism so that the closed condition is not reached.
The arrangement and the structural design of the displacement portions 41 and 42 correspond substantially to those according to FIG. 24 . This applies analogously to the displacement parts 7 according to FIGS. 15 and 25 .
In FIG. 18 , it can especially be seen that the respective guide elements 31 and 34 are arranged on the upper and lower narrow sides 47 and 48 of the displacement plate 37 in question. In addition, FIGS. 18 and 20 describe a displacement part 7 with two displacement plates, cf. also FIGS. 19 and 20 , which are arranged parallel to one another and which are both provided with respective guide elements 31 , 32 and 33 , 34 . The guide elements are essentially circular, cf. also FIG. 20 , and are inserted into complementary circular openings of the guide sleeves 35 and 36 . The guide elements taper and can thus be assigned more easily to the reception openings 52 of the guide sleeves 35 and 36 .
The displacement portions 41 and 42 , cf. also FIGS. 19 and 20 , are laterally fastened to the handling end portion 49 in a releasable manner. In the respective fastening areas, elastic inserts 50 are arranged. Although these elastic inserts 50 allow the guide elements to extend precisely linearly, a certain elasticity of the guide elements and of the displacement portions relative to the handling end portion 49 is, however, possible.
The handling end portion 49 is provided with a reception means or a coupling for a respective unit of the ROV for handling the displacement part 7 .
The structural design of the displacement part 7 is configured analogously in the case of an arrangement of a displacement portion on only one side of the handling end portion 49 , cf. e.g. the provision of the guide unit 30 on only one side of the separator according to FIG. 7 .
FIGS. 21 and 22 show additional embodiments of displacement parts 7 . The cooperation of these displacement parts with the application parts takes place analogously to the other embodiments and will here not be described in detail. Also the structural design of the separator is essentially identical, cf. the respective clutch components 4 , 5 and application parts 6 , 26 associated therewith. In the case of the embodiment according to FIG. 21 , a difference exists insofar as the application part 26 projects directly from the second clutch component 5 , cf. in this respect the slightly different structural design according to FIG. 7 .
Another difference exists with respect to the way in which the displacement part 7 is guided relative to the module housing 29 , which does not comprise any guide sleeves in this case. Nor is the displacement part 7 provided with rod-shaped guide elements, said rod-shaped guide elements being replaced by rotatable guide balls on the upper and lower narrow sides 47 , 48 of the displacement plate 38 of the displacement part 7 . This applies analogously also to the displacement part 7 according to FIG. 22 .
In FIG. 21 a few positions of the application part 6 relative to the displacement bevel 43 and of the application part 26 relative to the displacement bevel 45 are indicated by broken lines.
When the displacement part 7 is being inserted, it moves, cf. in this respect again the statements made in connection with FIGS. 15 to 17 , from the lower position shown in FIG. 21 up to and into the upper position shown. This applies analogously to the application part 26 , which also moves from a lower position into an upper position, said movement taking, however, place with a time shift to the movement of application part 6 . This means that the clutch components are decoupled and the second clutch component is raised, cf. e.g. FIG. 14 .
The displacement parts 7 of the hitherto described embodiments each had two displacement portions 41 and 42 , whereas the displacement part 7 according to FIG. 22 , cf. the displacement plate 39 , only has one displacement portion 41 . This displacement portion 41 has, on its upper and lower narrow sides, the displacement bevels 43 and 44 which respectively come into contact with the two application parts 6 and 26 . This has the effect that the application part 6 is raised by the displacement bevel 43 , cf. in this respect also FIGS. 11 and 12 , whereas the application part 26 and, consequently, the second clutch component 5 are displaced downwards by the displacement bevel 44 , cf. in this respect also FIG. 13 .
FIGS. 23 to 25 show various displacement parts 7 once more. Also the displacement part 7 according to FIG. 23 only has one displacement portion 41 of a displacement plate 40 analogously to FIG. 22 . This arrangement essentially results in a displacement of the clutch components according to FIG. 13 .
The displacement part 7 according to FIG. 24 comprises two displacement portions 41 and 42 , the displacement portion 41 with its displacement bevel 43 raising the first clutch component of the application part 6 and displacing, through of its displacement bevel 44 and the displacement bevel 45 of the displacement portion 42 , the second clutch component by means of the application part 26 to a position at which the operating mechanism is open to approx. 50%.
The displacement part 7 according to FIG. 25 leads to an essentially 100% opening of the operating mechanism by raising the second clutch component in an appropriate manner, cf. also FIG. 14 .
From the above it can be seen that the separator according to the present invention comprising a displacement part offers a plurality of possibilities of adjusting the actuator and the associated operating mechanism, said adjustment possibilities concerning not only a decoupling of these two elements but also a displacement of an operating element of the operating mechanism by an external mechanical action via a ROV.
In addition, only some of the large number of variations are described in the figures enclosed, additional variations being possible by providing the displacement portions with a suitable shape and length and the displacement bevels with a suitable inclination.
All this is possible on the basis of an only simple linear movement of the respective displacement part by means of the ROV so as to eliminate in certain cases the cooperation of the actuator and of the operating mechanism. An electric or hydraulic supply is not necessary for this separation. In addition, it is not necessary to take any structural measures with respect to the actuator or the operating mechanism, since the respective separator can simply be arranged between these two elements. Suitable standard fastening areas, to which the separator according to the present invention is adapted, can be used. This also applies to the mode of fastening by means of screws or the like.
Likewise, it is possible that respective displacement parts can easily be retracted by the ROV so that the operating mechanism can then be repositioned by means of the actuator.
|
The separator serves to mechanically separate an actuator and an operating mechanism, such as a choke, a valve, a blow-out preventer or the like, which is displaceable by said actuator, for use especially in the field of oil or natural gas production. The separator is adapted to be arranged between the actuator and the operating mechanism and comprises at least a first component associated with the actuator and a second component associated with the operating mechanism. These first and second components are displaceable relative to one another by means of at least one application part, which is connected to the first or second component, between an engagement position and a release position. The application part is adapted to be brought into releasable engagement with a displacement part which is suitable for handling by a user. This allows the actuator and the operating mechanism to be easily separated by the respective separator, without said separator leading to any structural modifications or enlargements of the actuator and/or operating mechanism. In addition, the separator is easily operable especially by an external user, and a predetermined displacement of the operating mechanism is made possible.
| 4
|
UNITED STATES. PATENT DOCUMENTS
[0001]
[0000]
5,256,710
October 1993
Krivohlavek
5,750,598
May 1998
Krivohlavek
6,569,925
May 2003
Baumgardner
BACKGROUND TO THE INVENTION
[0002] 1. Field of this Invention
[0003] This invention relates to a non-free sulfur cured polymer modified asphalt composition comprising a polymer modified asphalt, a proprietary non-free sulfur curing agent and organic acid activator.
[0004] 2. Description of Prior Art
[0005] Pavements are made with blends of asphalt and aggregate, typically in the ratio of 5 to 7% of asphalt in 93 to 95% of aggregate mixed at elevated temperatures ranging from 173° C. to as high as 250° C. or higher. In order to get the mix done at this high temperatures, the contractors generally have to get asphalt delivered to the construction site hot, heating from the time the asphalt is prepared ready for delivery to the site. It can take anywhere from 24 to 72 hours from the time the asphalt is warmed up to the time it is used at the construction site. This time period may even be longer if the asphalt were required to be polymer modified as the modification normally takes between one hour and 24 hours, depending on the type of polymer selected for the blend. In the process of heating the asphalt, especially the polymer modified version, the high heat tends to degrade the polymer and renders the desirable properties of the polymer ineffective. Hence there is a need for an additive or additives that would improve the heat resistance of the asphalt-both neat and polymer modified. We have perfected a system that would resist the heat degradation of asphalt. The system uses a proprietary vulcanizing additives product to cure the polymer modified asphalt. In asphalt, cure has traditionally been with elemental free sulfur. Free elemental sulfur does not contribute to resistance to heat aging of the asphalt. On the contrary free sulfur accelerates the heat aging of asphalt, and in particular the polymer that is present in polymer modified grades. In addition, free sulfur creates fire hazard which had resulted in many fire accidents in the past during the addition of sulfur to asphalt. Also, free sulfur addition results in objectionable odor from oxides of sulfur developed during the hot mixing process.
[0006] In the past many non-sulfur free cure systems were developed for use in curing asphalt. One of them is U.S. Pat. No. 5,256,710 issued on Oct. 26, 1993 to Dennis Krivohlavek that discloses a composition of phenolic or phenol-formaldehyde two-step resins either alone or in combination with each other for curing polymer modified asphalt. Also it discloses the mixture that may be used in combinations with elemental sulfur, as cross-linking or co- vulcanization catalysts or agents and (optionally) process oils to produce a product of enhanced performance suitable for commercial, construction and other industrial applications where asphalts or bitumen are to be used. It is different from the present invention in that it uses phenolic or phenol formaldehyde cure systems. In addition it also recommends its use with elemental sulfur both of which are not part of the cure components in the present invention. Nor is the phenol formaldehyde system disclosed in U.S. Pat. No. 5,256,710 has any claim with respect to improved resistance to heat aging and the ability to retain higher elastic properties.
[0007] One other patent awarded to Mr. Gayton L. Baumgardner et al, U.S. Pat. No. 6,569,925 issued on May 27, 2003 resembles some parts of the present invention in the components which are termed as accelerator-gel additives. The primary objective of that patent as spelt out under the title “Objects and Summary of the Invention” states that: “1) To provide a stable, composition for delivering accelerator into the liquid polymer-asphalt mixing during the production of polymer modified asphalt 2) To provide a stable accelerator-gel suspension that will not separate during storage or during manufacturing processes incorporating its use such as when added to the polymer asphalt system 3) To provide a stable accelerator-gel additive that may be premixed and stored at ambient temperature and is of a liquid or gel nature that offers ease of handling and pumpability under the normal processing conditions and at temperatures below 140°F.” That invention does not at any point claim to provide enhanced resistance to heat aging, nor retain the asphalt blend's elastic properties under long duration of heating at high temperatures. Furthermore, U.S. Pat. No. 6,569,925 characterizes sulfur as an accelerator, contrary to the claim it is sulfur free. Hence there is no relevance between the present invention and that of Mr. Gaylon's.
[0008] Other than that there are no other patents from our search having similar invention to address the problem of heat aging and retention of elastic properties. Therefore, there is a need for a solution to develop an asphalt composition with additives that confer heat resistance, and which at the same time cures the asphalt without elemental sulfur.
[0009] In the light of the problems associated with extensive heating of polymer modified asphalt during the preparation and subsequent storage and transportation at high temperatures to the road construction site, it is the objective of the present invention to provide a an asphalt composition that has chemical curatives without any elemental sulfur for the purpose of curing the asphalt.
[0010] It is another objective of this present invention to provide safe non-free sulfur preparation of asphalt composition that eliminates toxic fumes which is typical with addition of elemental sulfur to highly heated asphalt blends. In addition it is also another objective of the invention to provide an asphalt composition conferred with resistance to heat aging of the asphalt, and in particular the polymer present in the asphalt with elemental sulfur-free chemical for curing.
[0011] It is also a further objective of the invention to confer heat resistance to the asphalt/polymer blends in order to retain the elastic properties of the polymer in the blends, thus providing better service life of pavement under freeze and thaw conditions in cold weather.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The present invention is related to composition and preparation of a polymer modified asphalt blend with enhanced resistance to heat aging at elevated temperatures for extended length of time.
[0013] The composition comprises a polymer modified asphalt, a cure chemical made from reaction product of sulfenamides and inorganic oxides in combination with organic acids that together when heated in the polymer modified asphalt medium cross links the polymer and to certain extent the asphalt. This can be used in the normal course of blending polymer in asphalt and curing for road pavement, tack coat and chip seal applications. It is also useful in cross linking asphalt roofing insulation and road crack sealants to increase their service life.
[0014] The accelerator/organic oxide reaction product, a proprietary curative manufactured and sold under the name of “EcorCure” by Quantum Polymer Composites of Cleveland, Ohio comes in the form of thick paste which when warmed up turns to free flowing viscous liquid.
[0015] An activator may be added to increase the reaction of the curing agent “EcorCure.” The activators for the cure may be selected from the group comprising organic acids, namely Stearic Acid, Palmitic Acid, Oleic Acid and Linoleic Acid or combinations thereof. The organic acid activators may be in liquid, pastilles, flakes or pellets.
[0016] The polymer used in the polymer modification of the asphalt is devulcanized tire rubber manufactured and sold by Quantum Polymer Composites of Cleveland, Ohio. The devulcanized tire rubber is sold under the brand name of “ECORPHALT.” It is processed from rubber recovered from used tires. Hence it has some carbon black and other chemicals used in tire manufacture. ECORPHALT comes in the form of free flowing pellets. It is dissolved in asphalt using a high shear stirrer, and heated to around 173° C. for anywhere between 30 minutes and 6 hours depending on the source and grade of asphalt used. Besides ECORPHALT, other traditional polymers selected from the group comprising Natural Rubber (NR), Synthetic Polyisoprene rubber (IR), Styrene Butadiene Rubber (SBR), Butyl Rubber (BR or IIR for Isobutylene Isoprene Rubber), Styrene, Butadiene Styrene block copolymer (SBS), Styrene, Isoprene, Styrene Rubber (SIS), Styrene, Ethylene Butylene Styrene Rubber (SEBS), and Ethylene Propylene Diene Monomer or commonly known as EPDM Rubber or blends thereof.
[0017] The asphalt selected are from the group comprising asphalts derived from petroleum distillation process, naturally occurring asphalt, asphalt from various petroleum sources and blends thereof. The asphalt vary from source to source in their composition and their physical properties such as viscosity.
[0018] Finally the asphalt blend according to this invention is prepared by first selecting the asphalt, the polymer's, the ECORPHALT, the proprietary ECORCURE, Organic Acid/s, and then blending them in the following sequence to asphalt that is heated to around 173° C. while mixing using high shear stirrer.
[0019] First the selected polymer or polymers is added slowly over 5 to 10 minutes.
[0020] Next the mix is continued to be stirred for further 30 minutes before adding the organic acid, again slowly over a 3 to 5 minute period.
[0021] Followed by further stirring for additional 30 minutes before adding the ECORCURE which can be injected into the asphalt being stirred with no time lapse.
[0022] The mix is then continuously stirred for further 30 minutes to 4 hours. The mix is ready for use at the end of this process.
[0023] The resultant polymer modified asphalt cured with non-free sulfur vulcanizing composition, ECOCURE, exhibits high degree of resistance to heat aging and degradation relative to those cured with elemental sulfur.
[0024] The foregoing features and process techniques can be modified, combined or substituted by one skilled in the art. Hence it is intended that our claims to cover all additions, modifications, combinations and permutations.
|
This invention relates to an asphalt composition cured with non-free sulfur components that enhance its elastic properties and at the same time increases its resistance to degradation due to high heating for prolonged period as practiced in asphalt preparations for road pavement.
| 2
|
BACKGROUND OF THE INVENTION
Telephony-over-local area network (ToL) systems allow computers on local area networks (LANs) or packet networks to function as telephony clients. While such systems are advantageous in that a separate telephone need not be provided, the integration of the telephone with the computer means that a user of a telephony application can have access to the entire computer network.
While the use of a screen saver is known to prohibit unauthorized access to a computer without inputting an appropriate password, it is undesirable to have a conventional screen saver functioning during a ToL telephone conversation. For example, activation of a screen saver during such a conversation can cause the ongoing communication to fail, or can limit access to some features. As such, use of a screen saver is not an adequate solution to computer security during a ToL conversation.
Further, while systems are known which will “lock” a user into a particular window of a graphical user interface (GUI) during a particular process, such systems do not “unlock” the window until the function is completed. Thus, there is no way for a user to both execute the process and carry on another procedure using another program.
SUMMARY OF THE INVENTION
A telephony-over-LAN (ToL) system is provided having a graphical user interface (GUI) wherein an authorized or guest user may be locked within a ToL window, having full access to the ToL features, but denied access to other parts of the computer system. In such a system, the terminal user or subscriber may click on a “Guest” button on the ToL client GUI screen before leaving the computer. The ToL guest user may then execute the call normally. According to a first embodiment of the invention, the ToL client locks the user into the ToL client screen. Keystrokes and mouse cursor movements which would allow exiting the ToL client are prevented. According to a second embodiment, of the invention, the ToL client screen is “maximized” and the minimize or resize window functions are blocked. When the terminal subscriber returns, a password is entered to regain full access to the computer.
Broadly speaking, according to the present invention, a ToL controller is provided which monitors cursor and keyboard inputs, and prevents any commands from being executed which would allow an unauthorized user to exit the ToL client application or its associated window. The ToL controller is further configured to accept password authorization, to release the window or exit lock.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention is obtained when the following detailed description is considered in conjunction with the following drawings in which:
FIG. 1 illustrates an exemplary computer system according to an embodiment of the invention;
FIG. 2 is a block diagram of the computer system of FIG. 1 ;
FIG. 3A and FIG. 3B illustrate exemplary graphical user interface(s) according to an embodiment of the invention;
FIG. 4 is a diagram of an exemplary graphical user interface according to another embodiment of the invention;
FIG. 5 is a flowchart illustrating operation of an aspect of an embodiment the invention;
FIG. 6 is a flowchart illustrating operation of an aspect of an embodiment the invention; and
FIG. 7 is a flowchart illustrating operation of an aspect of an embodiment the invention.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to the drawings and, with particular attention to FIG. 1 , an exemplary computer 10 , including a system unit 11 , a keyboard 12 , a mouse 13 , and a display 14 are depicted. The computer 10 may include ToL client terminal functionality according to the present invention. The screen 160 of the display device 14 is used to present the graphical user interface (GUI) and particularly, the ToL client window 3008 . The graphical user interface supported by the operating system allows the user to employ a point-and-click method of input, i.e., by moving the mouse pointer or cursor 150 to an icon representing a data object at a particular location on the screen 160 and pressing one or more of the mouse buttons to perform a user command or selection. As will be explained in greater detail below, the computer 10 is configured to prevent an unauthorized user from accessing commands or selections which would access portions of the computer system external to the ToL client window or functions.
FIG. 2 shows a block diagram of the components of the personal computer shown in FIG. 1 . The system unit 11 includes a system bus or a plurality of system buses 21 to which various components are coupled and by which communication between the various components is accomplished. The microprocessor 22 is coupled to the system bus 21 and is supported by the read only memory (ROM) 23 and the random access memory (RAM) 24 also connected to the system bus 21 . The microprocessor 22 may be embodied as any of a variety of microprocessors, including the Intel x86, Pentium or Pentium compatible processors.
The ROM 23 contains among other code the basic input output system (BIOS) which controls basic hardware operations such as the interaction of the disk drives and the keyboard. The RAM 24 is the main memory into which the operating system and applications programs are loaded. The memory management chip 25 is connected to the system bus 21 and controls direct memory access operations including passing data between the RAM 24 and hard disk drive 26 and floppy disk drive 27 . The CD ROM drive 32 , is also coupled to the system bus 21 and is used to store a large amount of data, such as a multimedia program or a large database.
Also connected to the system bus 21 are various I/O controllers: The keyboard controller 28 , the mouse controller 29 , the video controller 30 , and the audio controller 31 . The keyboard controller 28 provides the hardware interface for the keyboard 12 ; the mouse controller 29 provides the hardware interface for the mouse 13 ; the video controller 30 is the hardware interface for the video display 14 ; and the audio controller 31 is the hardware interface for the speakers 15 and microphone 16 . The speaker 15 and the microphone 16 allow for audio communication during ToL operation.
An I/O controller 40 enables communication over a network 46 , such as a packet network. More particularly, the I/O controller 40 may be an H.323 Recommendation interface, to allow for telephony or multimedia communications via the packet switched network.
One embodiment of the present invention is provided as a set of instructions in a code module resident in the RAM 24 . Until required by the computer system, the set of instructions may be stored in another computer memory, such as the hard disk 26 , on an optical disk for use in the CD ROM drive 32 , or a floppy disk for use in the floppy disk drive 27 . As shown in the figure, the operating system 50 , the ToL client application 52 , the guest mode controller 54 , and the password database 56 are resident in the RAM 24 .
As will be discussed in greater detail below, the operating system 50 functions to generate a graphical user interface on the display 14 . The ToL application program 52 performs ToL functionality, including generation of a ToL client window in the GUI. The guest mode program 54 , which may be embodied as a component of the ToL client application 52 , functions to cause entry into and exit from a guest mode, as will be discussed in greater detail below. Finally, the database 56 stores a list of authorized users and their passwords.
Turning now to FIG. 3A , a diagram of an exemplary graphical user interface (GUI) according to an embodiment of the invention is illustrated.
The graphical user interface 3000 is representative, for example, of the Windows 95, Windows 98, Windows NT, or similar graphical user interfaces, available from Microsoft Corp. Other graphical user interfaces may be employed, however. As is known, the GUI program is part of the operating system 50 executed by the microprocessor 22 . The microprocessor 22 sends signals to the video controller 30 , which displays the GUI 3000 on the graphic display 14 .
As shown, the GUI 3000 includes a ToL client window 3008 . A location of the ToL client window 3008 relative to other portions of the GUI 3000 and other items on the screen are maintained in a known manner. In particular, the system (i.e., the microprocessor 22 ) is always aware of the locations of boundaries of the ToL client window 3008 .
The ToL client window 3008 includes thereon a cursor 3012 . Movement of the cursor 3012 is accomplished via manipulations of the mouse 13 , which sends signals to the mouse controller 29 and/or the microprocessor 22 in a known manner. The video controller 30 then processes signals received from the microprocessor 22 to display the cursor on the graphic display 14 . An exemplary ToL client window 3008 is the GUI for the Siemens HiNet™ RC 3000 system, available from Siemens.
The GUI 3000 further includes one or more second windows 3010 , which are representative of, for example, other applications programs, such as word processors or spreadsheets. Further, one or more icons 3002 , 3004 , 3006 , representative of other applications programs may be available.
Also included in the ToL client window 3008 is a Guest icon 3013 according to the present invention. Clicking on the guest icon 3013 will cause entry into a guest mode according to the present invention, wherein a guest user is locked or prevented from accessing portions of the computer system, such as the one or more other windows 3010 , or the one or more program icons 3002 , 3004 , 3006 , other than the ToL client window 3008 .
More particularly, manipulations of the mouse 13 , in conjunction with location information regarding the cursor 3012 are received as signals by the mouse controller 29 and analyzed by the microprocessor 22 . As is known, manipulations of the mouse are translated into a coordinate system of the cursor 3012 relative to the ToL client window 3008 and the GUI 3000 , generally. According to the present invention, the movements of the cursor 3012 external to the ToL client window 3008 are disallowed, and the cursor 3012 is prevented from exiting the ToL client window 3008 .
In addition, the microprocessor 22 monitors signals received from the keyboard controller 28 . The keyboard controller 28 sends signals to the microprocessor 22 indicative of manipulations, i.e., keystrokes, on the keyboard 12 . Such keystrokes may include manipulations of letters, numbers, or function keys, or combinations thereof. In guest mode, the microprocessor 22 disallows any commands which would allow exit from the ToL client window 3008 and therefore access to other portions of the computer system.
It is noted that, alternatively to or in conjunction with the features described above, entry into the guest mode may cause the microprocessor 22 to issue one or more commands to the video controller 30 to “blank” the screen external to the ToL client window 3008 . Thus, for example, the icons 3002 , 3004 , 3006 and the window 3010 may be blended into the wallpaper or otherwise concealed from view.
FIG. 3B illustrates a variant on the above-described embodiment. In particular, the ToL client window 3008 is shown in an expanded or maximized state, wherein the ToL client window 3008 is maximized to fill the entire GUI screen 3000 . As is known, this may be accomplished through clicking on a Maximize button. If the ToL client window 3008 is already in the maximized state when the Guest button 3013 is clicked, the guest user will be prevented from minimizing or otherwise altering the size of the ToL client window 3008 . Thus, the guest user will be prevented from even seeing other portions of the screen of the GUI 3000 . Also, as in the above embodiment, keystrokes on the keyboard 12 are prevented from allowing the guest user to exit the ToL client window 3008 .
Once the guest user has finished his telephone call, the ToL client subscriber may click on the Guest button 3013 again (or another button which provides the same functionality). In response, the microprocessor 22 accesses the guest mode program 54 and sends a command to the video controller 30 to display the password window 4000 ( FIG. 4 ). The password window 4000 includes a password entry field 4002 and an Enter button 4004 . The ToL client subscriber may type the password into the password entry field 4002 and click the Enter button 4004 . The microprocessor 22 reads the password and accesses the database 56 to determine whether the entered password is the same as a stored password. If so, the guest mode is released and the ToL client user may access other portions of the computer system. It is noted that the password may be the user's network log in password, or may be a separate password independently set. Further, the microprocessor 22 may be programmed to prevent the release from guest mode if a predetermined number of incorrect password entries have occurred.
Turning now to FIG. 5 , a flowchart illustrating password setting according to an embodiment of the invention is shown. In particular, in a step 5002 , the ToL client user clicks the guest button or otherwise accesses a guest mode preferences screen (not shown). For example, a manipulation of the mouse 13 , such as double clicking, is interpreted by the microprocessor 22 as a command to access such a screen. In a step 5004 , the user may select a password entry mode, for example, by clicking an appropriate menu choice or icon. The microprocessor 22 receives a corresponding signal from the mouse controller 29 and generates a password entry screen, which may be similar to the password screen 4000 ( FIG. 4 ). In a step 5006 , the ToL client user enters a user selected password into a password entry screen and clicks or otherwise causes the microprocessor to read the entered password. In a step 5008 , the ToL client user may be presented with the password entry screen again, to confirm proper entry of the password. Once the password entry has been confirmed (i.e., the previously entered password compared with the confirmation password), the password is stored by the microprocessor in the database 56 on the hard disk. Finally, in a step 5012 , the ToL client user may exit from the password entry mode.
Operation of the guest mode is shown in greater detail with reference to FIG. 6 . In particular, in a step 6002 , the ToL client user may click on the guest button, if a guest user has need to use the ToL telephone. As discussed above, this causes the microprocessor 22 , responsive to the ToL application program 52 and the guest mode program 54 , to enter into a guest mode wherein the guest user is prevented from accessing other portions of the computer system. Thus, in a step 6004 , the microprocessor “locks” the guest user into the ToL client window, which may include blanking other portions of the GUI screen or maximizing the ToL client window. In steps 6006 and 6008 , the microprocessor monitors keyboard keystrokes and mouse movements. Thus, the microprocessor 22 monitors the inputs from the mouse controller 29 and the keyboard controller 28 for any which would be unauthorized. For example, the microprocessor 22 may compare the movements of the cursor 3012 with the coordinates of the ToL client window. If a manipulation of the cursor would result in its leaving the ToL client window, it is prevented. Thus, in a step 6010 , the microprocessor determines, for each entry or signal received from the keyboard controller 28 and the mouse controller 29 , whether a command is authorized. Authorized commands are those which relate to movements of the mouse or cursor within the ToL client window or which pertain to ToL client functionality. If a command is authorized, the system proceeds with and executes it, in a step 6014 . If, however, the command is unauthorized, no action will be undertaken, other than, perhaps, to display a warning message, in a step 6012 .
Once the guest user has finished his call, the ToL client user may cause the system to exit the guest mode, as shown in the flowchart of FIG. 7 . In a step 7002 , the ToL client user clicks on the guest button 3013 . This causes the microprocessor 22 to cause the display of the password window 4000 ( FIG. 4 ), in a step 7004 . The ToL client user then types in the password and the microprocessor determines whether the entered password is correct, in a step 7006 . For example, the microprocessor 22 may access a database in the disk drive and compare the stored password with the entered password. If the password is correct, then in a step 7008 , the microprocessor releases the system from the guest mode and allows access to the entire computer system. However, if the password is determined not to be correct, then the guest mode is not released. In such a case, a limit on the number of password entry tries may be provided. Further, it is noted that the subscriber may release the guest mode according to the method of FIG. 7 while a call is ongoing.
|
A telephony-over-LAN (ToL) system having a graphical user interface (GUI) wherein an authorized or guest user may be locked within a ToL window, having full access to the ToL features, but denied access to other parts of the computer system. In such a system, the terminal user or subscriber may click on a “Guest” button on the ToL client GUI screen before leaving the computer. The ToL guest user may then execute the call normally. According to a first embodiment of the invention, the ToL client locks the user into the ToL client screen. Keystrokes and mouse cursor movements which would allow exiting the ToL client are prevented. According to a second embodiment, of the invention, the ToL client screen is “maximized” and the minimize or resize window functions are blocked. When the terminal subscriber returns, a password is entered to regain full access to the computer.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Patent Application Ser. No. 60/825,286, filed Sep. 12, 2006, the entirety of which is incorporated herein by reference.
FIELD OF INVENTION
The present invention relates to the field of solid state switching devices. In particular, to a solid-state switch with short circuit protection.
BACKGROUND
A switching circuit, such as a relay or a triac, is typically employed to switch high voltage/power circuits with a lower voltage/power control signal. The control signal is generated by a secondary (control) device. Current switching applications (for example a Class 2 application switching a voltage less than 30V) typically use switching technologies including relays or triac devices. Other applications may include opto-isolated Field Effect Transistors (FET); typically, these circuits are limited to maximum load currents of a few milliamps (mA).
FIG. 1 is a schematic representation of an exemplary relay switch 100 that works through energizing (V Con ) a coil 110 that acts as a magnet to pull down a gate 120 that connects a high voltage (V High ) to the power circuit and enables a current flow. Latching relays (not illustrated) can have one or two coils. An impulse closes the circuit and a feedback loop keeps the gate closed. A reverse pulse opens the circuit or a second coil is energized to open the circuit.
The following limitations with relays are based on the analysis of a Class 2 application operating below 30V alternating current (AC). These limitations may also apply to circuits operating outside the 30V AC range:
When used in an application such as thermostat control, the operating voltage is typically 24V and the dissipation is 140 mW (for a non-latching relay). The operating range of a thermostat is between 18 and 30V, and at 30V the power dissipation increases to 220 mW. The thermostat control can typically run three devices (i.e. three loads each having an associated relay) resulting in a total power dissipation of approximately 600 mW. This adds significant heat to a temperature sensitive thermostatic control. A further limitation of relays is arcing. Arcing occurs when the load current momentarily bridges the air gap as the relay gate opens. This causes electromagnetic (EM) noise and radio frequency (RF) interference that can adversely affect the operation of the thermostat, or other devices, particularly RF devices. In addition, when opening the relay gate, the sudden cutting off of control current in the relay coil also causes a momentary voltage spike in the control circuit potentially causing failure in the electrical components of the device. Secondary parts such as voltage suppressors can be used to reduce the voltage arcing, although these add to cost and space requirements on circuit boards. A relay can also degrade over time and may be ineffective when switched from a high power to a low power application. The contact surfaces wear out which degrades their ability to form a proper contact in a low power application. The relay is also limited in the number of times it can switch in a lifetime, typically from 100K to 1M operations. Switching of the relay is limited to a few cycles per minute. In the event of a controller failure, the coil may be latched and continue running the appliance indefinitely (applies to latching relays only). There is no inherent short circuit protection on a relay device. Relays (regular and especially the latching type) are typically more expensive and occupy more volume than corresponding solid state devices.
The following limitations with triacs are based on the analysis of a Class 2 application operating below 30V AC. These limitations may also apply to circuits operating outside the 30V AC range:
Triacs can only operate in an AC application (i.e. with an AC powered load). Triacs require a switching current and have a typical voltage drop of 1-2V. They are not suitable for millivolt (mV) applications. A limitation to triacs also relates to brownout conditions. In a brownout condition, the controlled voltage can drop to 18V. If a triac operates with a 2V drop, an overall 16V signal may be too low for proper operation. Since the control signal is 5 to 20 mA, the heat dissipation can be significant. Triacs usually require secondary circuitry to isolate the source and switching voltage. This is commonly done with opto-couplers which add to overall costs of the device. By way of an example, a Triac switching 300 mA of current per circuit with 3 circuits active at once having a 2V drop will dissipate 1.8 W of power, which will add significant thermal offset to a thermostat application where accurate temperature readings are desired. In comparison, an exemplary MOSFET circuit in a similar application will dissipate 0.054 W of power. Triacs may have leakage current through the device. In a low power application, the small (leakage) current may be interpreted as a false signal.
What is needed is a switching mechanism for switching high voltage/power circuits with a lower voltage/power control signal that mitigates some or all of the disadvantages described above.
SUMMARY OF INVENTION
A solid state switch that employs a controller driven input, and MOSFET power switching devices is disclosed. The controller can test for a short-circuit on the load side of the MOSFET power switching devices before putting the switch in a sustained conductive state.
In one aspect of the present invention there is provided, a method of operating a microprocessor controlled solid-state switch having a metal-oxide semiconductor field-effect transistor (MOSFET) based output stage for switching a load, the method comprising the steps of: receiving a command to put the solid-state switch in a conductive state; checking a wait timer for a zero duration; repeating the step of checking, when the duration is non-zero; generating an input signal pulse from the microprocessor to put the output stage in a conductive state, when the duration is zero; taking a sample voltage at the output stage; responsive to the sample voltage, determining that the switch is in one of a short-circuit condition and a non-short-circuit condition; resetting the wait timer to a pre-determined non-zero value and repeating the step of checking, when the switch is in a short-circuit condition; and generating an input signal from the microprocessor to put the output stage in a sustained conductive state, when the switch is in a non-short-circuit condition.
In another aspect of the present invention there is provided, a solid-state switch, for switching a load, comprising: a booster circuit for receiving a substantially square-wave input signal, electrically decoupling the signal, and generating a control signal that is an amplified version of an envelope of the input signal; a filter circuit for receiving the control signal and reshaping the signal into a output stage driving signal having smaller rise and fall times; an output stage having one or more metal-oxide semiconductor field-effect transistors (MOSFET), for receiving the output stage driving signal and responsive to the output stage driving signal putting the MOSFET in one of a conductive and a non-conductive state; a microprocessor for: receiving a command to put the solid-state switch in a conductive state; checking a wait timer for a zero duration; repeating the step of checking, when the duration is non-zero; generating an input signal pulse from the microprocessor to put the output stage in a conductive state, when the duration is zero; taking a sample voltage at the output stage; responsive to the sample voltage, determining that the switch is in one of a short-circuit condition and a non-short-circuit condition; resetting the wait timer to a pre-determined non-zero value and repeating the step of checking, when the switch is in a short-circuit condition; and generating an input signal from the microprocessor to put the output stage in a sustained conductive state, when the switch is in a non-short-circuit condition.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art or science to which it pertains upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF DRAWINGS
The present invention will be described in conjunction with drawings in which:
FIG. 1 is a schematic representation of an exemplary relay switch.
FIG. 2 is a schematic representation of an exemplary solid-state switch in situ in an exemplary thermostat control.
FIG. 3 is a schematic representation of an exemplary boost circuit.
FIG. 4 is a schematic representation of an exemplary signal V Control .
FIG. 5 is a schematic representation of an exemplary signal V Threshold .
FIG. 6 is a schematic representation of an exemplary filter circuit.
FIG. 7 is a schematic representation of an exemplary signal V MOS .
FIGS. 8A and 8B are schematic representations of exemplary output stages.
FIG. 9 is a schematic representation of an exemplary signal V Out illustrating a normal and a short circuit condition at zero crossing.
FIG. 10 is a schematic representation of a DC signal V Out illustrating a normal and a short circuit condition.
FIG. 11 is a flowchart representing steps in an exemplary control algorithm for the solid state switch.
FIG. 12 is a schematic representation of a configuration for detecting short circuits at the output stage 240 .
DETAILED DESCRIPTION
FIG. 2 is a schematic representation of an exemplary solid-state switch 200 in situ in an exemplary thermostat control 250 . The solid-state switch 200 (herein after the switch) comprises a controller driven input 210 , a boost circuit 220 , a filter circuit (a.k.a. a latching circuit) 230 , and an output stage 240 . The controller driven input 210 can, for example, receive a signal from a microprocessor 270 (e.g. the Microchip Technology Inc. PIC 18F6527) or other similar well known programmable device (e.g. microcontrollers, Programmable Gate Arrays (PGA), Programmable Logic Arrays (PLA), Application-Specific Integrated Circuits (ASIC)) capable of providing a control function signal. The exemplary thermostat control 250 comprises a power supply 260 , an alternating current (AC) to direct current (DC) converter 265 , a signal conditioning unit 262 , a microprocessor 270 having an analog to digital converter 275 , a communication unit 280 , a display unit 285 , buttons 290 for user input, sensors 295 and one or more solid state switches 200 .
FIG. 3 is a schematic representation of an exemplary boost circuit 220 . The boost circuit 220 is provided with a low power high frequency signal (V 1 ) at the input 210 by the microprocessor 270 . The signal V 1 is boosted through the boosting circuitry through the combination of a resistive network (R 1 & R 2 ) and an NPN transistor (N 1 ). Voltage V 2 is substantially higher than the maximum voltage of the signal V 1 . Voltage V 2 can be derived from the AC-DC converter 265 (connection not illustrated). Further, the circuit uses two capacitors (C 1 & C 2 ) to provide signal isolation. The isolated signal is passed through a peak-detector which uses two diodes (D 1 & D 2 ) and a capacitor (C 3 ). The output of the boost circuit is referred to as V Control . The smaller the capacitance of C 1 & C 2 , the greater the isolation. The increased isolation comes at the expense of increased rise and fall times (i.e. increased wave-like attenuation of the signal) of V Control . FIG. 4 is a schematic representation of an exemplary signal V Control and the signal V 1 from which it was derived. In FIG. 4 and in all other figures in this document representing voltage signals the vertical dimension represents voltage increasing from bottom to top and the horizontal dimension represents time increasing from left to right, unless otherwise specified. The output signal V Control represented in FIG. 4 is the result of applying a square wave input signal V 1 to the boost circuit 220 . The increased rise and fall times can be seen in the sloped vertical signal components and the rounded shoulders of the signal V Control .
The output signal V Control is an amplified version of the envelope of signal V 1 . The waveform of signal (V Control ) is unfavorable for application to MOSFET devices due to the highly resistive nature of MOSFET devices when turned on at V Threshold . FIG. 5 is a schematic representation of an exemplary signal V Control . In FIG. 5 the vertical axis represents the internal resistance of a MOSFET device, increasing from bottom to top, and the horizontal axis represents time increasing from left to right. The label V Threshold on the horizontal axis represents the point in time that corresponds to the gate voltage applied to the MOSFET device achieving V Threshold . In an illustrative example represented in FIG. 5 , the MOSFET device is in series with a 24Ω load. At 24V and 1 A of load current, the power loss through the MOSFET during switching would be substantial when switching is prolonged (i.e. the time delay to achieving V Threshold is significant), which would significantly impact the operation of a temperature sensitive device such as, for example, a thermostat control. Further, the power dissipation through the MOSFET could lead to its destruction under short circuit conditions.
FIG. 6 is a schematic representation of an exemplary filter circuit 230 . To address the above described problem, the signal V Control is fed through the filtering circuit 230 comprised of a resistive network (R 3 to R 6 ) and transistor network (N 2 & N 3 ) that create an output signal V MOS for input to the output stage. FIG. 7 is a schematic representation of an exemplary signal V MOS and the signal V Control from which it was derived. The waveform (V MOS ) has a substantially square waveform that significantly limits the time in which the MOSFET transistors operate in a highly resistive mode during on/off transitions. By improving the rise and fall times compared to V Control the signal V MOS minimizes the delay in achieving V Threshold at the gate of the MOSFET devices.
FIG. 8A is a schematic representation of an exemplary output stage 240 . V MOS is fed into the output stage 240 . The output stage 240 comprises a dual N-channel MOSFET circuit (Q 1 and Q 2 ) that controls the output voltage V Out . The signal V MOS is applied to the gates of the MOSFET devices Q 1 , Q 2 . The load to be controlled (i.e. switched ON and OFF) and a high voltage (V High ) source (not illustrated) can be connected in series with the drains of the MOSFET devices Q 1 , Q 2 .
FIG. 8B is a schematic representation of an alternative exemplary output stage 240 comprising a dual P-channel MOSFET circuit (Q 1 and Q 2 ). The embodiment of FIG. 8B operates in substantially the same way as the embodiment of FIG. 8A except that signal V MOS is applied to the sources of the MOSFET devices Q 1 , Q 2 .
In a further alternative embodiment (not illustrated) for DC switching only, the output stage 240 comprises a single MOSFET device (Q 1 ). V High and the load are connected respectively to the drain and the source of Q 1 . V MOS is applied between the gate and the source of Q 1 .
Prior to the microprocessor 270 signaling the output stage 240 into a sustained ON (i.e. conductive) state, it can pulse the input 210 of the switch 200 and sample the voltage at the output stage 240 to detect short circuits in either AC or DC applications. FIG. 12 is a schematic representation of a configuration for detecting short circuits at the output stage 240 . The signal conditioning unit 262 is connected between the source of V High (e.g. power supply 260 ) and the output stage 240 in order to sense V High . The microprocessor 270 in conjunction with the signal conditioning unit 262 is able to analyze the sensed voltage V High .
FIG. 9 is a schematic representation of an exemplary sensed (i.e. sampled) signal V High illustrating (in the expanded views) both a normal (i.e. non-short-circuit) (V Normal ) and a short circuit (V short-circuit ) condition at zero crossing. A typical AC signal has a zero crossing where the slope of the change in voltage is at a maximum. At the zero crossing, the microprocessor 270 pulses the input signal V 1 to turn the output of the switch 200 on and tests the voltage at the crossing. If the slope (i.e. the rate of change of the voltage) is below a desired threshold (V Threshold ), the microprocessor 270 interprets that the load-side of the output stage 240 is in a short circuit state (V short-circuit ) and the microprocessor stops (i.e. de-asserts) the signal V 1 , allowing the output stage 240 to go into an OFF (i.e. open) state preventing damage to the output stage 240 and connected devices (e.g. the load).
FIG. 11 is a flowchart representing steps in an exemplary control algorithm (i.e. method) 1100 for the solid-state switch 200 . The method 1100 allows the microprocessor 270 to detect an unexpected slope and reset the output stage 240 to an OFF state. The microprocessor 270 receives an ON command 1110 which, in the example of a thermostat application, may be a signal to turn on the fan, heat, AC, or other external circuits. A “wait” timer is checked 1120 . When the timer duration is non-zero, it indicates that a short circuit fault has been previously detected and processing returns to step 1120 . The timer duration is zero (“0”) 1130 when no short circuit fault has been previously detected or when a previously non-zero timer duration has expired; processing continues at step 1140 . The microprocessor 270 detects a zero voltage crossing 1140 , generates a short duration series of output driving pulses 1150 , takes a sample of the AC voltage and computes the slope 1160 . If the signal slope (e.g. V Normal ) is greater than the threshold slope (V Threshold ) 1170 indicating a non-short-circuit (i.e. normal) condition, then the microprocessor activates the desired output 1180 . If the signal slope (e.g. V short-circuit ) is less than the threshold slope (V Threshold ) indicating that a short circuit is detected, then the microprocessor resets the timer duration to a predetermined non-zero value 1190 .
Referring again to FIG. 12 , in an alternative embodiment of the apparatus and method for the solid-state switch 200 , in order to detect a short circuit on the output stage 240 in a DC application (i.e. a DC load), an inductor 300 is placed in series with the load 310 between the power supply 260 (i.e. the source of V High ) and the output stage 240 and V High is sensed for analysis. In an alternative embodiment (not illustrated), the inductor is placed between the output stage 240 and the load and V Load is sensed for analysis. FIG. 10 is a schematic representation of an exemplary DC signal V High illustrating both a normal (i.e. non-short-circuit) and a short circuit condition. Instead of measuring the change in slope as in the AC application, the microprocessor 270 tests for a drop in voltage V High to below a pre-defined threshold. Upon short circuit detection, the microprocessor 270 resets the “wait” timer to a non-zero value.
In a further alternative embodiment for use in a DC application, no inductor is needed when the impedance of the power supply (i.e. the source of V High ) is sufficiently high so that the output stage 240 is not damaged during the brief period of the short-circuit analysis.
The method according to the present invention can be implemented by a computer program product comprising computer executable instructions stored on a computer-readable storage medium.
It will be apparent to one skilled in the art that numerous modifications and departures from the specific embodiments described herein may be made without departing from the spirit and scope of the present invention.
|
A solid state switch that employs a controller driven input and MOSFET power switching devices is disclosed. The controller can test for a short-circuit on the load side of the MOSFET power switching devices before putting the switch in a sustained conductive state.
| 7
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for mining coal with a heated basic aqueous fluid to form coalate, and removing the coalate from the coal formation.
2. Prior Art
It is generally known that coal is removed from the ground using two methods, either strip mining, in which the coal is merely dug out of the ground by mechanical or hydraulic means and transferred to the place of use, or underground mining using methods such as slurry mining (see U.S. Pat. No. 3,260,548 to Reichl), room and pillar, or longwall. The means for taking the coal out of the ground in the room and pillar or longwall methods are generally mechanical cutters, rippers, planers, loaders, etc. In slurry mining hydraulic apparatus is used to direct pressurized water at the coal seam to disaggregate the coal and form a slurry which is then pumped out of the mine to the surface. In all of these coal mining techniques it is first necessary to loosen the coal from the formation using some means such as explosives, hydraulic pressure, or physically contacting the coal with cutters, etc., before the coal can be transported away from the mine and to the place of use. Such methods require much time and large capital outlays for expensive loosening equipment.
Attempts have been made in the coal industry to find an agent which would attack the coal in such a way that the bonds between the coal constituents would be weakened and mechanical separation of the coal could be facilitated. Such a process is taught by U.S. Pat. No. 1,532,826 to Lessing, wherein the coal is treated with an acid or an aryl amine to facilitate mechanical segregation of the coal. Although such an acid treatment facilitates disaggregation by mechanical means the treatment does not result in complete disaggregation of the coal. Somewhat greater disaggegation of coal by solutions containing sodium hydroxide, among other constituents, is taught by U.S. Pat. No. 3,815,826 to Aldrich et al.
It has now been discovered that by contacting a coal formation of high oxygen content coal with a heated basic aqueous solution, particularly sodium hydroxide, the coal can be substantially dissolved. Although it has been generally known that finely ground bituminous coal can be treated with an aqueous alkali solution at elevated temperatures to obtain a coke-like residue, and that the hydrogenation of these residues forms products which are more hydrocarbon-like in nature than does a similar hydrogenation of the coal itself, (see for example "Action of Aqueous Alkali on a Bituminous Coal" by Leo Kasehagen in Industrial and Engineering Chemistry, May, 1937), it was surprising indeed to discover that coal of relatively high oxygen content may be mined when contacted with a heated basic aqueous solution and dissolved in situ. This phenomena can be utilized to remove a complete coal formation more easily than the coal could be mechanically removed or removed by slurry mining. Further, the basic aqueous solution can be regenerated with an agent such as an acid or base.
SUMMARY OF THE INVENTION
Broadly, this invention is a process for dissolving subterranean coal of high oxygen content which comprises contacting said coal with a heated basic aqueous solution, preferably sodium hydroxide, for a time sufficient to dissolve the coal. This invention can also be used to dissolve subterranean coal in beds which outcrop from the surface of the earth. It will be appreciated that, when the process of this invention is used to recover coal from an underground formation, it is preferred to first penetrate the coal bed with at least one borehole, then pump the heated basic aqueous solution down the borehole to contact the underground seam of coal. Either periodic or continuous enlargement of the wellbore in the vicinity of alkali injection by removal of some of the dissolved coal is necessary to continue dissolution of the coal.
The heated basic aqueous solution is maintained in contact with the coal for a time sufficient to substantially dissolve said coal. The coal thus dissolved can then be transported to a receiving terminal, preferably above ground, either by mechanical means or by application of pressure to the coalate in the mine.
In another aspect of this invention, after the coalate has been removed to the surface or another convenient location, the aqueous base is regenerated with an acid or base.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified diagram of the cross section of a single borehole communicating between the surface of the earth and a coal seam.
FIG. 2 shows a cross section of a formation penetrated by at least two boreholes.
DETAILED DESCRIPTION OF THE INVENTION
In its broadest aspect, the process of the instant invention pertains to the dissolution of relatively high oxygen content coal in situ and removal from the coal seam. Coal generally refers to the commonly known substance which is a solid, brittle, more or less distinctly stratified, combustible carbonaceous rock, which has been formed by partial-to-complete decomposition of vegetation over a period of many years, and varies in color from dark brown to black. Coal is entirely different from oil shale or tar sand. The coal is generally not fusible without decomposition, and has limited solubility in most solvents. The types of coal which can be dissolved, using the process of this invention, include all coals of high oxygen content, such as lignite, sub-bituminous, bituminous of various classifications, i.e., low, medium, and high rank bituminous; semi-bituminous coal, semi-anthracite, anthracite, and super-anthracite coal. Generally it is found that the process is particularly useful for sub-bituminous coal of high oxygen content, especially those deposits found in Western U.S., such as in the Big Horn Mine, WY.
While it is not completely understood how contacting with heated basic aqueous solutions such as caustic solutions causes high oxygen content coal to substantially dissolve, and it is not desired to be bound by any particular theory, it is though that the primary cause of the reaction is the dissolution of constituents of the coal which behave like humic acids. That is, humic acid-like material of the coal, which has been formed from vegetable matter, is more subject to attack by the basic solution than others. The basic solution dissolves this material, thus forming channels within the coal, ultimately weakening the binding and the adhesion between the coal constituents, and causing the coal to substantially dissolve.
The heated basic aqueous solution contemplated for use in the process of the invention is a water solution of a basic substance, i.e., a substance which, when added to water, will increase the hydroxide ion concentration of the water. Generally, this includes many oxides and hydroxides such as those of the alkaline metals, i.e., sodium, lithium, potassium, and the like. Of these sodium hydroxide is particularly preferred. Other heated basic aqueous solutions such as alkaline carbonates or bicarbonates, e.g., sodium carbonate and sodium bicarbonate, may also be used in the process of this invention, but with a lesser degree of effectiveness. The solutions useful in the process of this invention vary in strength from a lower range of about 0.5 percent by weight (% w) of the basic substance, and preferably 2% w, to an upper range of about 20% w, preferably about 5% w, depending on solubilities of the basic substance. It appears that generally the amount of basic substance needed to effectively dissolve the coal will range from about a lower limit of 0.2 part up to about 1 part by weight of the basic substance per part by weight of coal, and not much advantage is gained by exceeding about 0.3 parts base per part coal.
Generally, it is found that the effectivenss of the treatment of high oxygen content coal increases with increasing temperature, that is, the coal dissolves more completely in a given time period as the temperature increases. Thus, the temperature range over which the coal can be treated with the heated basic aqueous solution extends substantially over a range of temperatures from about 175° C to substantially higher, depending of course upon pressures employed. For the more practical pressures envisioned, this temperature range is approximately from 175° to 250° with 200° C being about optimal for Big Horn coal. At 250° C it is necessary to go to special materials of construction such as Hastelloy and similar corrosion resistant materials which reduce the economic attractiveness of the process.
The length of time which the basic aqueous solution must be held in contact with the coal appears to depend upon the type of coal, as well as the strength and temperature of the basic solution. Generally, the more concentrated and heated the base is, the faster the dissolution will be, and generally the process is most effective on high oxygen content sub-bituminous and bituminous type coals. Generally, at the base/coal ratios given above, it is found that the contact time will be less than 48 hours and preferably less than 12 hours but more than 1 hour.
The pressure at which the reaction is carried out can be atmospheric, sub-atmospheric, or super-atmospheric. However it is preferred to use a pressure which is atmospheric or above depending on the depth of the coal formation being treated. Pressure should be adequate to prevent formation fluid invasion and interruption of solution injection. In cases where no communication with outside fluids exists it may be desirable to maintain sufficient pressure to support overburden and prevent collapse into the process zone.
The gaseous environment in which the coal is treated may be inert or reactive, but is preferably inert, i.e., an environment which does not substantially react with the coal, such as nitrogen or methane.
Although, as pointed out above, the process of this invention comprises dissolving a coal bed that is below the surface of the ground by contacting with a basic aqueous solution, if the basic aqueous solution is used to treat a bed of coal that outcrops at the surface of the earth, i.e., an open pit mine, coal can be dissolved completely by treatment with the basic aqueous solution and is therefore more readily removable.
The coal can be contacted in any of the methods known in the art. For instance, if the coal is in an open pit mine, the basic aqueous solution can merely be poured or pumped to the exposed surface of the coal and allowed to contact the coal until it dissolves sufficiently to be removed. The dissolution can be speeded up by circulating the basic aqueous solution over the surface of the coal. It is also foreseen that heated basic aqueous solution could be sprayed onto the coal at hydraulic pressures sufficient to assist in the dissolution of the coal.
The basic aqueous solution can be regenerated by several routes. For example, if heated aqueous sodium hydroxide were utilized to form liquid sodium coalate, the sodium hydroxide can be regenerated by reacting the sodium coalate with CO 2 gas or carbonic acid to form acid coalate. Generally, strong acids such as nitric, sulfuric, hydrochloric, etc. work better than weaker acids such as carbonic, acetic, etc. Instead of an acid, another base may be utilized to regenerate the basic aqueous solution employed to form the coalate. Again taking sodium coalate as an example, sodium hydroxide can be regenerated therefrom by reacting the sodium coalate with calcium hydroxide to form calcium coalate and sodium hydroxide. Other bases such as barium hydroxide and magnesium hydroxide work well, as do all of the oxide and hydroxides of the alkaline metals. Other materials may precipitate the coalate without regenerating the basic aqueous solution. For example, calcium chloride (or some other metal halide) will precipitate calcium coalate but produce sodium chloride instead of the more desired sodium hydroxide.
Reference is made in the following discussion to FIG. 1 for the purposes of further explaining the process of this invention but not in a limiting manner. Where the coal lies beneath the earth's surface 17, it is preferred to carry out the process of this invention by penetrating the overburden 14 and the coal seam 13 so that communication is established between the surface and the coal seam. The penetration of the coal bed is generally done by any known methods of drilling and establishing a borehole 10 communicating between the earth's surface 17 and the coal formation 13 underground. When communication has been established, the heated basic aqueous solution from storage 18 is passed through the borehole 10 and into contact with the coal bed 13. This can be done merely by pumping the heated basic aqueous solution through the well borehole so that the solution contacts the coal at the lower end of the borehole. To increase initial contact, a cavern 15 may be formed around the underground end of the well borehole, by explosive means, hydraulic pressure, or mechanical means known in the art, so that more surface area of the coal is exposed to the heated basic aqueous solution when it is pumped down. In order to increase the contact of the heated basic aqueous solution with the surface of the coal even more, the formation may be fractured by any of the conventional methods known in the art, such as hydrofracting, explosive means, nuclear means, etc. Further, if the coal is associated with water-soluble minerals, these minerals can first be dissolved out by passing water through the borehole into contact with the water-soluble minerals, and withdrawing the solution of water-soluble minerals in the water. Thereafter, the heated basic aqueous solution can be pumped down the borehole to contact the exposed coal surfaces. If the water-soluble minerals are base-forming, the heated basic solution formed by injecting heated water may be left in contact with the coal for a time sufficient to dissolve it.
The process of the invention may be carried out by installing a tubing string 12 down the center of borehole 10. The heated basic aqueous solution is pumped down the annular opening 11 into contact with the coal, then the coalate is pumped out of contact through tubing string 12 to the receiving terminal 16. The roles of tubing and the annular opening may be reversed.
In some cases it is preferable to penetrate the coal formation with at least two boreholes, as shown in FIG. 2 -- one an injection well 20 and the other a production well 21, then fracturing the formation, using conventional means mentioned before, or otherwise creating permeable connections between wells such as drilling or mining, to establish communication between the two wells, and pumping the head basic aqueous solution down the injection well into contact with the coal formation, through the fractures 22 to the production well, and out the production well. The heated basic solution is maintained in contact with the coal for a sufficent time to dissolve the coal. In some cases, it is preferable to penetrate the formation with more than one injection well and more than one production well surrounding the injection wells, establishing communication between the injection wells and the production wells, passing the heated basic solution through the injection wells to the formation and out through the various production wells. This can be done using generally any type of well configuration taught in the prior art such as 5, 7, 9 and 13 spot patterns.
After communication is established between the surface and the coal seam using one of the techniques described above, the coal is contacted with the heated basic aqueous solution for a period of time sufficient to dissolve the coal and form a solution which is then transferred out a tubing string 12 (FIG. 1) or a production well 21 (FIG. 2) to a receiving terminal 16 for further treatment.
It appears that the basic material reacts with the coal to form a coalate solution. It is preferable to attempt to regenerate the basic material or the alkaline metal value from the coal at or near the point at which the coalate is taken from the ground. This may be done by treating the coalate to extract the alkaline metal values prior to extracting energy values from the coalate, or the coalate may be first used to recover energy values and thereafter the alkaline metal may be recovered, e.g. from the remaining ash after burning the coalate to obtain heat values.
This invention will be further explained in detail with reference to the following embodiments which are given in way of illustration only and not by way of limitation.
EXAMPLES
The products from a given batch of Big Horn coal treated with excess sodium hydroxide solution at 250° C were analyzed. Results showed that approximately 85 percent of the dry coal treated was converted to gaseous or water-soluble products and that the undissolved residue contained essentially all of the original coal ash. Humic acid products with an equivalent weight range of 625 ± 50 grams made up most of the dissolved products and when recovered as acid precipitated material had heat contents slightly higher than the original coal. Calcium hydroxide added to solutions of the humic acids resulted in the precipitation of insoluble complexes. The data below were obtained from a single 200 gram moisture-free sample of Big Horn coal treated with approximately 4 molar sodium hydroxide solution.
The coal sample with 600 ml distilled water and 100 grams sodium hydroxide were charged to a one liter, high pressure, Hastelloy `B`, lined reactor. The sealed vessel was then heated in a forced air convection oven at 250° C for 24 hours. After the reaction mixture was cooled, undissolved gases were recovered, and the reactor contents were diluted with water, centrifuged, and the insoluble fraction washed extensively. Combined washings and filtrate were finally diluted to 5,500 ml and are subsequently referred to as the "5,500 ml" solution.
In addition to coal dissolution products the "5,500 ml" solution contained a significant quantity of unreacted sodium hydroxide. The products in solution included CO 2 (present as Na 2 CO 3 ), sodium humate and the sodium salts of some low molecular weight organic acids.
Undissolved components included a small quantity of gases and an insoluble residue of coal. A material balance for the 200 gram, moisture-free coal sample is shown in Table 1. There is a small uncertainty in the weight of product described as "acid soluble components". These low molecular weight, colorless organic acids (remaining in solution after acid precipitation of humic acids) were estimated by measuring the quantity of non-carbonate carbon in solution. The results were then treated as if all the dissolved carbon were present as acetic acid which is probably the major solution component after removal of humic acid.
Table 1 also shows the small quantity of gases, others than CO 2 , which were evolved with sodium hydroxide dissolution of the coal. A mass spectrometric analysis of these gases is given in Table 2.
That fraction of the coal sample which was not dissolved by treatment with sodium hydroxide is the 16 percent "insoluble residue" of Table 1. Essentially all the inorganic material in the original coal is contained in this residue. Its ash content is 26.2 percent.
The humic acids yield shown in Table 1 is a mean value for results obtained by three separation methods. These data are given in Table 3. The material recovered is described as `humus` in Table 3 to indicate the product is free of moisture and ash and has been calculated to a humic acid basis. Analyses for products actually separated by precipitation with hydrochloric acid, carbonic acid, and calcium hydroxide are shown in Tables 4, 5 and 6 respectively.
In the calcium humate separation, Table 6, carbonate present as sodium carbonate in the "5,500 ml" solution was coprecipitated with calcium humate complex. This accounts for the large quantity of ash shown in the product analysis. Calcium content of the ash by atomic absorption analysis was 59.7 percent and sodium content by the same procedure was 1.3 percent indicating 0.32 percent sodium by weight for the unashed calcium humate product. A spectrochemical analysis for the ash of Table 6 is shown in Table 7. The presence of many of the elements seen here reflect the attack of sodium hydroxide on the Hastelloy reactor liner.
Table 8 gives heats of combustion values determined for the insoluble residue, gases and dissolution products from the "5,500 ml" solution. About 76 percent of the recovered heat value is in the humic acids. The heat content is approximately 64 percent of the original moisture-free coal and their heat value per unit weight is slightly more than that of the moisture-free coal; 12,600 Btu/lb for the humic acids vs. 12,370 Btu/lb for moisture-free Big Horn coal.
Total oxygen in the combined dissolution products is about 27 percent by weight. In comparison the oxygen content of moisture-free Big Horn coal is about 16.9 percent. The relatively large quantity of oxygen taken up with sodium hydroxide dissolution offers some explanation for the missing heat in Table 8. The exothermic heat accompanying these hydrolytic reactions is evidently on the order of 2,000 Btu/lb moisture-free coal (16.4 percent of 12,370 Btu/lb = 2,029).
Table 1______________________________________APPROXIMATE MATERIAL BALANCE FORBIG HORN COAL SAMPLE TREATED WITHSODIUM HYDROXIDE (200 GRAM SAMPLE) Weight % M. F.Product (grams) Sample______________________________________Gases (other than CO.sub.2) 0.02 0.01Insoluble Residue 33.38 16.15Humic Acids 125.73 60.83Carbon Dioxide* 24.65 11.93Acid Soluble Component** 22.90 11.08Total 206.68 103.34______________________________________ *Determined as Na.sub.2 CO.sub.3 by potentiometric and conductometric procedures. **Calculated as Acetic Acid based on dissolved non-carbonate carbon determination.
Table 2______________________________________GASES OTHER THAN CO.sub.2 * PRODUCED WITHSODIUM HYDROXIDE DISSOLUTION OF BIG HORNCOAL (GAS YIELD VOLUME APPROXIMATELY 40 ML)______________________________________ mol %Component (Normalized)______________________________________Hydrogen 58.27Methane 32.48Ethane 4.94Propane 3.16Butane 1.15Total 100.00______________________________________ *Approximately 12 percent of the moisture free sample was converted to CO.sub.2 by treatment with sodium hydroxide. These results are given in Material Balance, Table 1.
Table 3______________________________________RECOVERY OF HUMUS MATERIAL FROM"5500" SODIUM HUMATE SOLUTIONSeparation Humic Recovered Method (gram/liter)______________________________________Hydrochloric Acid 23.04Carbonic Acid 22.85Calcium Hydroxide 22.70Mean 22.86______________________________________
Table 4______________________________________ELEMENTAL ANALYSIS OF HCl-PRECIPITATED HUMIC ACIDS FROM "5500" SOLUTION______________________________________Element Wt %______________________________________Carbon 73.17Hydrogen 5.13Nitrogen 1.34Sulfur 0.51Oxygen* 16.85Ash 3.00______________________________________ *Oxygen by different
Table 5______________________________________HUMIC ACIDS PRECIPITATED FROM "5505"SOLUTION WITH CARBONIC ACIDElement Wt %______________________________________Carbon 72.18Hydrogen 5.14Nitrogen 1.33Sulfur 0.48Oxygen* 18.25Ash 2.62______________________________________ *Oxygen by difference
Table 6______________________________________HUMATES PRECIPITATED FROM "5500"SOLUTION WITH CALCIUM HYDROXIDEElement Wt %______________________________________Carbon 48.98Hydrogen 3.72Nitrogen 0.96Sulfur 0.30Oxygen* 22.28Ash** 23.76______________________________________ *Oxygen by different **Ash includes calcium used to precipitate calcium humate, as well as calcium consumed in precipitating carbonate ion as CaCO.sub.3.
Table 7______________________________________SPECTROCHEMICAL ANALYSIS FOR 800° C ASH FROMCALCIUM HYDROXIDE PRECIPITATED HUMATES______________________________________Element %______________________________________Aluminum 1.00Barium 0.02Boron 0.70Calcium* 59.70Chromium 0.20Cobalt 0.03Copper 0.02Iron 2.00Magnesium 1.00Manganese 0.06Molybdenum 0.03Nickel 0.05Silicon 6.00Sodium* 1.35Strontium 0.02Titanium 0.20Vanadium 0.05______________________________________ *Results by Atomic Absorption Analysis
Table 8______________________________________HEAT BALANCE FOR BIG HORN COAL SAMPLETREATED WITH SODIUM HYDROXIDE(5461 BTU IN COAL CHARGED) Heat of CombustionProduct (Btu)______________________________________Gases 1Insoluble Residue 759 (13.9%)Humic Acids 3,493 (64.0%)Carbon Dioxide 0Acid Sol. Components 315 (5.7%) Total 4,568 = 83.6%Loss or Unaccounted For 893 = 16.4%______________________________________
|
This invention is a process for mining an underground formation of coal having high oxygen content by contacting the coal with a heated basic aqueous solution for a time sufficient to dissolve at least a portion of the coal formation to produce a coalate. Periodically or continuously, some of the dissolved material is removed to facilitate or improve access to the coal formation. The dissolved coal or coalate is then treated with a regenerating agent to recover basic aqueous solution from the coalate.
| 4
|
This application is division of application Ser. No. 09,414,175, filed Oct. 7, 1999, now U.S. Pat. No. 6,321,493.
FIELD OF THE INVENTION
The present invention relates generally to connectors for tubular skylights.
BACKGROUND
Tubular skylights have been provided for illuminating the interiors of buildings in an aesthetically pleasing and energy efficient way with natural sunlight. An example of a commercially successful skylight is disclosed in the present assignee's U.S. Pat. No. 5,099,622, and further examples of effective tubular skylights are disclosed in the present assignee's U.S. Pat. No. 5,896,713 and in allowed U.S. patent application Ser. No. 09/126,331, all of which are incorporated herein by reference.
In tubular skylights such as the those mentioned above, a transparent plastic dome is mounted on a roof of a building by means of a metal flashing that is attached to the roof. Extending down from the dome is a metal tube that has a highly reflective inner surface. The tube extends down to the ceiling of the interior room sought to be illuminated, where it terminates at a disk-shaped light diffuser mounted on the ceiling by means of one or more support rings that engage the lower end of the tube.
It will be appreciated that with the above general description of tubular skylights in mind, many components must be connected together. As but one example, the tube itself is ordinarily made from a flat sheet of metal that is bent into a cylindrical shape to form the tube, with the opposite ends of the sheet of metal slightly overlapping each other in the cylindrical configuration and being held in the cylindrical configuration by manually taping the length of the joint between the ends of the bent sheet. As understood by the present invention, while effective, the above-mentioned manual means for forming the tube can result in tubes having diameters that might exhibit deviations slightly from design. Moreover, it is sometimes desirable that the tube slightly taper, i.e., assume a slightly frustoconical shape, and it is difficult to precisely configure a tube to have such a shape using the manual taping method described above. Fortunately, the present invention recognizes that it is possible to easily and with a high degree of repeatability effect a precisely-configured skylight tube.
As another example, consider the connection between the plastic dome and metal flashing. A metal screw is advanced through an ABS washer that is positioned in a hole in the dome, and the screw engages the metal flashing. As recognized herein, the washer can sometimes undesirably rotate in the hole of the dome, thereby rendering it less than optimally effective as a connection interface with the screw and, hence, the flashing to which the dome is mounted.
As yet other examples, connecting the diffuser and the various support rings to the lower end of the tube and to the ceiling must be accomplished in relatively confined areas, and accordingly can be a cumbersome and time-consuming task. The present invention understands that such connections can be effected quickly and securely by the novel connecting systems and methods disclosed herein.
SUMMARY OF THE INVENTION
A light transmitting member for a skylight includes a sheet defining opposed axial edges. The sheet can be bent into a light transmitting configuration, wherein the axial edges are juxtaposed with each other and a light transmitting channel is established by the sheet. First and second sets of axially spaced tab elements are formed along respective axial edges of the sheet. A first tab element in the first set includes a tab while a second tab element in the second set defines a tab opening. As disclosed in detail below, the tab is movable between an engage configuration, wherein the tab can be received through the tab opening, and a lock configuration, wherein the tab cannot be removed from the tab opening to thereby hold the sheet in the light transmitting configuration. Indeed, at least upper and lower tab elements include respective tabs and respective tab openings, and the tab of each tab element in a pair is receivable through the tab opening of the other tab element in the pair.
In a preferred embodiment, each set of tab elements includes at least two tab elements. The tab elements in the first set are juxtaposed with respective tab elements in the second set when the member is in the light transmitting configuration to establish plural tab element pairs. Each tab element is integral to the sheet, i.e., the sheet is cut to form the tabs, with the tabs being retained on the sheet by an uncut living hinge.
Furthermore, the sheet is formed with at least two upper tab elements in each set of tab elements. The upper tab elements of one set are axially and radially spaced from each other to facilitate selectively establishing one of: a frusto-conical shape, and a cylindrical shape, of the sheet in the light transmitting configuration.
In another aspect, a method for forming a skylight tube includes providing a sheet defining first and second opposed edges, and forming plural tabs along at least the first edge and forming plural tab openings along at least the second edge. The method further includes advancing the tabs through respective tab openings with the sheet in a light transmitting configuration. Then, the tabs are bent to hold the sheet in the light transmitting configuration.
In yet another aspect, a skylight tube includes a sheet having a reflective surface. Fasteners are formed integrally on the sheet. The fasteners can be moved to hold the sheet in a light transmitting configuration, wherein the reflective surface is an inside surface.
In another aspect, a skylight dome fastener adaptor includes a hollow body defining an outer surface. Plural ribs are formed on the outer surface and are configured for engaging a hole in a skylight dome in an interference fit to impede rotation of the body in the hole.
In still another aspect, a lower skylight assembly includes a skylight dress ring that has a vertical flange formed with at least one clip hole. A skylight support ring has a vertical flange closely spaced from the vertical flange of the dress ring and terminating in a horizontal flange defining a ratchet aperture. Per present principles, a zip clip has an elongated body defining opposed first and second elongated surfaces, and a clip protrudes from one of the surfaces and is received in the clip hole of the dress ring. Also, at least one of the surfaces of the zip clip is formed with ratchet structure that engages the ratchet aperture of the support ring to thereby hold the dress ring onto the support ring.
In yet another embodiment, a zip tie has an elongated body defining first and second ends. A ratchet structure is formed on the body. Moreover, a clip arm is attached to and extends perpendicularly away from the first end of the body. Still further, the clip arm defines a channel. The channel is configured to receive a threaded fastener in self-tapping threadable engagement.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a skylight tube sheet prior to fastening the sheet in the light transmitting configuration;
FIG. 2 is a perspective view of a skylight tube sheet in the light transmitting configuration in an exploded relationship with a skylight dome and a diffuser plate;
FIG. 3 is a perspective view of the skylight dome fastener adaptor, in exploded relationship with a skylight dome, fastener, and flashing, with portions of the dome and flashing cut away for clarity;
FIG. 4 is a partial cross-sectional view of the lower end of a skylight, showing a zip clip engaging the dress ring with the support ring, with the zip clip illustrated as being displaced into the support ring to better illustrate the ratchet opening;
FIG. 5 is a cross-sectional view of the present zip tie with dry wall screw receiving channel, in operable engagement with a ceiling ring and dress ring.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIGS. 1 and 2, a light transmitting member is shown, generally designated 10 , for transmitting light from a roof-mounted plastic transparent dome 12 to a ceiling-mounted diffuser plate 14 . As disclosed in detail below, the member 10 can be formed in a cylindrical configuration or in a slightly tapered, i.e., frusto-conical, configuration to establish a skylight tube.
As shown in FIG. 1, the member 10 includes a metal sheet 16 that defines opposed axial edges 18 , 20 . When the sheet 16 is bent in the light transmitting configuration shown in FIG. 2, the axial edges 18 , 20 are closely juxtaposed with each other and indeed overlap each other. In the light transmitting configuration, the sheet 16 defines a light transmitting channel 21 that is bounded by an inside surface on which is disposed a reflective coating 22 , to render the inside surface highly reflective.
In accordance with the present invention, to provide a means for holding the sheet 16 in the light transmitting configuration shown in FIG. 2, fasteners are formed on the sheet 16 . More specifically, first and second sets 24 , 26 of tab elements, generally designated 28 , are formed integrally in the sheet 16 along respective axial edges 18 , 20 , as best shown in FIG. 1 . The tab elements 28 in a set accordingly are axially spaced from each other. More specifically, each set 24 , 26 of tab elements includes two upper elements 28 as shown, two lower elements 28 , and a single middle element 28 , although other element patterns can be established in accordance with present principles. In any case, as can be appreciated in reference to FIGS. 1 and 2, the tab elements 28 in the first set 24 are juxtaposed with respective tab elements 28 in the second set 26 when the sheet 16 is in the light transmitting configuration, to establish plural tab element pairs for purposes to be shortly disclosed.
In the second set 26 of tab elements, the elements 28 are colinear with each other as shown in FIG. 1 . Also, in the second set 26 , the two upper and two lower tab elements 28 each include a respective tab 30 formed by a cut in the sheet 16 around three sides of the tab 30 , with a fourth side of the tab 30 being uncut and consequently establishing a living hinge 32 about which the tab 30 can be pivoted. The free end 34 of each tab 30 , i.e., the end opposite the respective living hinge 32 , can be rounded as shown for safety. When the tab 30 is pivoted away from the sheet 16 , a tab opening 36 is established as shown best in FIG. 1 . If desired, the tab of the middle tab element 28 M in the second set 26 can be removed, such that the middle element 28 M consists of a permanent aperture as shown in FIG. 1 .
The tab elements 28 in the first set 24 are essentially identical in construction and operation to the tab elements 28 in the second set 26 shown in FIG. 1 and described above, with the following exceptions. The top-most element 28 T, middle element 28 N, and bottom-most element 28 B are axially aligned with each other as shown. On the other hand, a second top element 28 TS that is closely spaced from the top-most element 28 T and second bottom element 28 BS that is closely spaced from the bottom-most element 28 B are axially aligned with other and are slightly axially and radially spaced from the top-most and bottom-most elements 28 T, 28 B, respectively. The middle element 28 N of the first set 24 of elements includes both a tab and a tab opening as shown.
With the above disclosure in mind, it may now be appreciated that the tab 30 of the top-most element 28 T in the first set 24 can be moved about its respective living hinge 32 to an engage configuration, wherein the tab 30 extends radially outwardly from the sheet 16 and the tab 30 can be received through the tab opening 36 of the corresponding tab element 28 in the opposite set 26 . Also, the tab 30 can be moved to a lock configuration, wherein the tab 30 is folded back away from the opening 36 in which it is received to overlap the sheet 16 , such that the tab 30 cannot be easily removed from the tab opening 36 (without bending the tab) to thereby hold the sheet 16 in the light transmitting configuration. Likewise, the tab 30 of the middle element 28 N in the first set 24 can be engaged with the middle element 28 M of the second set 26 , and the bottom-most element 28 B of the first set 24 can engage the corresponding element in the second set 26 of tab elements. It is to be understood that the tabs 30 in the second set 26 can be likewise interlocked with tab openings 36 in the first set 24 of tab elements. In the example above, the second top element 28 TS and second bottom element 28 BS are not used, and a skylight tube is provided that has a cylindrical configuration and a maximum diameter.
It is to be further appreciated that instead of using the top-most and bottom-most elements 28 T, 28 B, the second top element 28 TS and second bottom element 28 BS can be used in conjunction with the middle element 28 N of the first set 24 , thus providing a skylight tube with a cylindrical configuration and a minimum diameter. Still further, a skylight tube can be provided that has a slightly frusto-conical shape by using the top-most element 28 T, middle element 28 N, and second bottom element 28 BS of the first set 24 . Or, a skylight tube can be provided that has a slightly frusto-conical shape by using the second top element 28 TS, middle element 28 N, and bottom-most element 28 B of the first set 24 .
FIG. 3 shows a skylight dome fastener adaptor 40 that can be disposed in a hole 42 of a plastic transparent skylight dome 44 . The top lip portion of a metal flashing 46 can be juxtaposed with the dome 44 . The flashing 46 is formed with a hole 48 that is juxtaposed with the hole 42 of the dome 44 and that indeed is coaxial therewith. With this structure, the threaded shank 50 of a fastener 52 is advanced through the adaptor 40 and can be threadably engaged with the hole 48 of the flashing 46 (or with a nut opposite the hole 48 ) to hold the dome 44 against the flashing 46 .
As shown in FIG. 3, the adaptor 40 includes a hollow hard plastic rigid body 54 that defines an outer surface 56 , and plural, preferably three, ribs 58 are formed on the outer surface 56 . The ribs 58 engage the hole 42 in the skylight dome 44 in an interference fit to impede rotation of the body 54 in the hole 42 when torque is applied to the fastener 52 .
In the preferred embodiment shown, each rib 58 includes an axially aligned outer edge 60 and opposed ramped sides 62 , 64 that extend from the edge 60 to the outer surface 56 of the body 54 . Thus, the ribs 58 have triangular cross-sections. As intended by the present invention, the ribs 58 are formed integrally with the body 54 .
In one preferred embodiment, the body 54 is formed with opposed chamfered ends 66 , 68 as shown. If desired, each rib 54 can include respective rib extensions 70 , 72 that are formed on respective ends 66 , 68 of the body 54 .
Now referring to FIG. 4, a lower portion of a skylight assembly is shown, generally designated 80 . The assembly 80 includes a ring-shaped plastic skylight dress ring 82 that supports a disk-shaped diffuser plate 84 . In the preferred embodiment shown, the dress ring 82 is formed with a ring-shaped vertical flange 86 that in turn is formed with one or more clip holes 88 . Moreover, a metal or plastic ring-shaped skylight support ring 90 has a vertical flange 92 that is closely spaced from and parallel to the vertical flange 86 of the dress ring 82 . As shown in FIG. 4, the vertical flange 92 of the support ring 90 terminates at its upper edge in a ring-shaped horizontal flange 94 that defines at least one ratchet aperture 96 therethrough. A ratchet tooth 97 extends into the ratchet aperture 96 . If desired, a resilient ring-shaped rubber or plastic seal 98 can be disposed between the vertical flange 86 of the dress ring 82 and a lower metal skylight tube segment 100 .
In accordance with present principles, a flexible plastic zip clip 102 holds the dress ring 82 and support ring 90 together. To facilitate this, the zip clip 102 has an elongated body as shown that defines opposed inner and outer elongated surfaces 104 , 106 . A small parallelepiped-shaped clip 108 protrudes from the inner surface 104 , and the clip 108 is closely received in the clip hole 88 of the dress ring 82 . Furthermore, the outer surface 106 of the zip clip 102 is formed with zip tie-like ratchet structure 110 that is configured to engage the ratchet tooth 97 of the support ring 90 and thereby hold the dress ring 82 onto the support ring 90 . Both the clip 108 and ratchet structure 110 are made integrally with the body of the zip clip 102 .
In a particularly preferred embodiment, the dress ring 82 is formed with a ramp 110 that terminates in an abutment 112 . As shown in FIG. 4, the lower end of the zip clip 102 is sandwiched between the abutment 112 and the vertical flange 86 of the dress ring 82 , to support the zip clip 102 . If desired, a small piece of felt 114 can be glued into the ratchet aperture 96 , with the zip clip 102 being biased against the felt 114 as indicated by the arrow 116 in FIG. 4 .
FIG. 5 shows a flexible plastic zip tie 120 that includes an elongated body defining first and second ends 122 , 124 . A zip tie-like ratchet structure 125 is integrally formed on the zip tie 120 as shown. Furthermore, a rigid clip arm 126 is formed integrally with and extends perpendicularly away from the end 124 of the tie. In accordance with present principles, the clip arm 126 defines a channel 128 generally parallel to the body of the zip tie 120 and thus perpendicular to the clip arm 126 . It is to be appreciated in reference to FIG. 5 that the channel 128 receives a threaded fastener 130 , such as a dry wall screw, with the fastener 130 self-tapping in the channel 128 as it is engaged therewith.
With this structure, the zip tie 120 can be used to interconnect skylight assembly components such as a ceiling ring 132 and dress ring 134 holding a diffuser plate 136 with a portion of dry wall. More specifically, the zip tie 120 ratchetably engages the ceiling ring 132 and dress ring 134 in respective ratchet slots 138 , 140 , and then a structure such as a beam or ceiling or wall can be clamped between the arm 126 and ceiling ring 132 . Moreover, the fastener 130 can be manipulated to engage further wall or ceiling structure above the zip tie 120 . Completing the description of FIG. 5, the ceiling ring 132 engages a lower portion 142 of a skylight tube, and a resilient seal ring 144 can be sandwiched between the dress ring 134 and lower portion 142 .
While the particular SYSTEMS AND METHODS FOR CONNECTING SKYLIGHT COMPONENTS as herein shown and described in detail is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and is thus representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more”. All structural and functional equivalents to the elements of the above-described preferred embodiment that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for”.
|
Various skylight connectors are disclosed. A sheet is integrally formed with tabs along opposed axial edges of the sheet, and the sheet can be bent into a tubular configuration with the tabs along one edge engaging tab holes along the other edge and vice-versa to hold the sheet in the tubular configuration. Also, a skylight dome fastener adaptor includes a hollow body, and ribs are formed on the outer surface to engage a hole in a skylight dome to impede rotation of the body in the hole when a fastener is disposed in the adaptor and threadably engaged with a dome flashing. Additionally, various quick connect zip ties and clips are disclosed for quickly and easily engaging components of a skylight assembly.
| 4
|
BACKGROUND OF THE INVENTION
This invention relates to a shuttleless loom of the type having unidirectional weft thread carriers.
It is known that, in addition to conventional weaving looms wherein the weft thread is inserted between the warp threads by means of a shuttle, reciprocating to and fro and housing a spool or cop with the thread thereon, so called shuttleless looms have been developed, wherein the weft thread is inserted by a weft thread carrier which is spool-less and configurated such as to grip the weft thread at one side or end of the shed and release it at the opposite side or end after having crossed the whole width of the fabric. Specifically, a number of such carriers are provided, each carrier being first brought to a position for gripping the weft thread supplied by a spool arranged on a stationary support, and then thrown across the shed by means of a torsion bar which confers to the stationary carrier the necessary acceleration and velocity, as required by the weight and thickness of the weft and by the cloth width, whereafter the thread is cut off, the carrier brought to stop and then returned to its initial position, e.g. by means of a conveyor located under the warp. The carriers operate one after the other. Looms operating on this general principle are commonly referred to as Sulzer shuttleless looms.
The advantages provided by such looms over the looms of conventional design are noteworthy. Indeed, since it is no longer necessary to transfer the thread-carrying spool across the shed, it becomes possible to effect a marked reduction in the size of the movable carriers and, accordingly, in the moving masses involved, with resulting lower energy requirements and increased throwing velocities. This velocity increase brings about a remarkable increase in the production rate with respect to the traditional looms, for a given machine size.
By contrast to such advantages over the traditional looms, the shortcomings of the system just described should be taken into account. Firstly, it should be noted that the stopping of the carrier on completion of the weft insertion step causes a waste of useful energy, which becomes higher as the throwing velocity increases, that same energy amount having to be replenished on the next throw. Furthermore, the noise and vibration should not be underestimated which are constantly set up by the sudden stop of the carriers on completion of the weft insertion step. There exists also a limitation to the reciprocation speed of the sley which, when using high carrier throwing velocities, is bound to reciprocate so quickly that remarkable and unacceptable vibrations are generated as a certain throwing velocity is exceeded. The carriers themselves, owing to the mechanical stresses whereto they are constantly subjected along their tails and tips, have to be made of a suitable material. All this prevents the production rate of such known looms from exceeding a given output limit.
SUMMARY OF THE INVENTION
It is a primary object of this invention to overcome such limitations of the prior art by providing a shuttleless loom equipped with at least one unidirectional weft thread carrier, which loom is so constructed as to limit the energy consumption for a given working speed and is thus capable of higher performance rates, even at high speeds.
It is another object of the invention to provide a loom of the type described above, featuring an improved carrier throwing device which generates practically no vibration and noise.
A further object of the invention is to provide a loom of the type described above, which is capable of operating at higher speeds than hitherto possible with the conventional shuttleless looms.
These and other objects, which will appear from the following detailed description, are achieved by a shuttleless loom of the type having at least one unidirectional weft thread carrier, comprising a throwing and recovering device for said carrier, wherein said device includes a guide for said carrier between the carrier emergence area from the shed and the insertion area thereof into the shed, said guide having progressive deviation and reversal portions, respectively at said emergence area from the shed and said insertion area into the shed, and means in said guide for accelerating said carrier to bring it back to the initial throwing velocity.
Advantageously, said progressive deviation and reversal portions are respectively composed of a substantially "U"-shaped guide portion at the carrier emergence area from the shed, and of a circular guide portion at the carrier insertion area into the shed, said circular guide portion being substantially tangent to a linear return portion and linear throw portion of said guide, respectively, said acceleration means comprising a flywheel defining the inner wall of said circular guide portion and provided with entraining means for said carrier, means being further provided for controlling the throwing of said carrier out of said circular guide portion.
With such an approach, the carrier is no longer slowed down and stopped at the end of the shed crossing step and its throw energy no longer totally destroyed, as is the case with the Sulzer loom at the moment of impinging against the stop surface at the emergence from the shed, but is rather recovered for the most part, there occurring only a minimal loss due to resistances and friction. Since the carrier substantially maintains its throw energy, deducting the obvious losses, until it is returned to the throwing area, all that is required is to supply each carrier, before each new throw cycle, with that amount of energy as went lost during its motion. That energy amount may be supplied to the carrier during one or more revolutions within the circular guide, as entrained about by the flywheel. All this results in higher output rates than were obtainable with the Sulzer type of loom. Thanks to the higher carrier velocity provided, more time remains available for reciprocating the sley, which is then reciprocable at lower rates, thereby less vibration is generated. The re-use of the carrier energy leads to improved loom performance.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invention will become apparent from the following description of a preferred embodiment thereof, provided by way of example and illustrated in the accompanying drawings, in which:
FIG. 1 is a cross-sectional general layout view of a loom according to the invention, some details of the throwing and recovering device being omitted and appearing instead in the following figures;
FIG. 2 shows a detail of the throwing device in sectional view along the line II--II of FIG. 4;
FIGS. 3 and 4 show respectively a top view and a cross-sectional view along the line IV--IV of the device illustrated in FIG. 2;
FIG. 5 shows a detail of the carrier entraining means in the throwing device;
FIG. 6 is a view similar to FIG. 2 but illustrating the carrier throwing step;
FIG. 7 is a schematic elevational view of a loom according to the invention;
FIG. 8 shows a carrier for a loom according to this invention, the carrier being shown during the weft thread pick up step;
FIGS. 9 and 10 are, respectively, a top plan view and a front view of the carrier shown in FIG. 8; and
FIG. 11 shows the carrier of FIG. 8 at the moment of releasing the weft thread.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference initially to FIG. 1 of the drawings, the loom according to the invention comprises two side frames 1 and 2, between which the device for throwing and recovering the carrier 3 is located, the device comprising a guide 4 for the carrier, arranged to cause the carrier to move along a closed path one portion of which passes through the shed. The guide 4 includes arcuate deviation portions 4a and 4b at opposite sides of the loom for the progressive deviation and reversal of the carrier 3 from the linear throwing portion 5 to the linear return portion 4c, and viceversa.
The reference numeral 6 denotes generally the throwing assembly, to be described in detail hereinafter, while the numeral 7 denotes a thread guide for the weft thread 8, and 9 denotes a cutting device. The numeral 10 denotes the sley, of conventional design, carrying the reed 11, while 12 denotes the warp threads wherebetween the shed is defined.
The throwing assembly or device 6, shown enlarged in FIG. 2, comprises a supporting structure 13 affixed to the side frame 1 and defining a circular recess or cavity 14 wherein a flywheel 15 is rotatably mounted, the cavity 14 and the flywheel 15 being so dimensioned and shaped peripherally as to define a circular guide 16. In the supporting structure 13, moreover, linear guide portions 17 and 18, respectively for throwing and returning or recovering the carrier 3, are provided which are substantially tangent to the circular guide 16. The flywheel 15 is integral with the shaft 19, supported by the structure 13 and driven by the machine own drive means, not shown, at an angular velocity such as to produce a flywheel peripheral speed equal to the desired throwing speed.
The flywheel 15 is provided with carrier entraining means, e.g. a pawl or dog 20 (or even a number of such pawls 20), projecting from the flywheel periphery and preferably seated resiliently in a seat 21 of the flywheel under the action of a bias spring 22 which tends to hold the pawl out of the bottom of the flywheel 15 peripheral groove.
At the connection area of the linear portion 17 with the circular guide 16, a swingable door 23 is located rigid at one end of an arm 24 mounted pivotally on the structure 13 at 25 so as to be swingable in a plane perpendicular to the axis of the flywheel 15. The door 23 is housed in an aperture of the structure 13 and has an arcuate shape such as to define a peripheral wall portion of the circular guide 16 when in the closed position illustrated in FIG. 2. At the end of the arm 24 opposite to the door, the end of a spring 26 is attached, the other end thereof being attached to the structure 13 at 27. A locking lever 28, pivotally mounted to the projection 29 of the structure 13 and program controlled between the positions shown in dotted and full lines in FIG. 2 allows the door 23 to be opened. The timed opening of this door for the carrier throwing is obtained for example through a cam control, including a cam 30 having a recessed portion 31 and followed by the tip of an arm 32 rigid with the arm 24. The cam 30 is driven to rotate by the shaft 19 through a pair of gears 33,34 so designed that one revolution of the cam 30 corresponds to one or more complete revolutions of the flywheel 15. As deductible from FIGS. 2 and 6, the embodiment shown is so conceived that the opening of the door 23 is only made possible when the lever 28 is in the position shown in dotted lines in FIG. 2 (corresponding to that shown in full lines in FIG. 6). In the unreleased condition shown in full lines in FIG. 2, the door 23 cannot be opened and the arm 32 simply overrides the low portion 31 of the cam, since the biassing action of the spring 26 is absent, with no danger for the whole assembly. The opening of the door 23, i.e. the shifting of the stop lever 28 to the position shown in dotted lines in FIG. 2, is controlled by a central control system: the stop lever 28 is normally held in the dotted position shown in FIG. 2 (corresponding to the position shown in full lines in FIG. 6), thus allowing the opening of the door 23 at each revolution of the cam 30, whereas, in the event of a thread breaking or for other reasons, it can be driven to the position shown in full lines in FIG. 2, thereby to prevent the opening of the door and thus the throwing of the carrier, even if the flywheel is rotating.
At the connection area of the linear recovery or return portion 18 with the circular guide 16, a swingable door 35 is provided which is configurated such as to complete the outer peripheral part of the circular guide 16 in said connection area. The door 35 may be moved automatically to the position of FIG. 6 when the carrier arrives, or may be shifted under control.
A bobbin carrier 36 is arranged fixedly on the support structure 13 and supports a spool 37 carrying the weft thread 8. The numeral 38 denotes a vacuum nozzle effective to hold the thread 8 within the path of the carrier emerging from the throwing assembly 6 (FIG. 2), the nozzle being located upstream with respect to the cutting members 9.
FIG. 7 shows how the throwing assembly 6 is timed to the movement of the sley 10, as required, the motion both of the assembly 6 and the sley being derived from the main drive shaft 39. The shaft 19 of the flywheel 15 is driven through a bevel gear pair 40, while for the reciprocating motion of the sley 10 there is provided, in a known manner, a reciprocating structure 41 which carries the sley 10 and is linked to the loom frame at 42. The reciprocating structure 41 carries the eyelets 43 for guiding the carrier and, on the opposite side, a cam following roller 44, arranged to engage a cam 45. Such an engagement is ensured by a spring 46. The ratios of the various gears and the angular arrangement of the cams 30 and 45 are such as to produce one stroke of the sley after each throw, after the carrier has crossed the shed. The numeral 47 denotes the heddles, of conventional design, and 48 the beam taking up the cloth 49.
The operation of the device just described is the following.
The carrier 3, before being thrown, is centrifuged in the structure 13 by means of the flywheel 15 and pawl 20, the door 23 being closed. Thus, the carrier acquires the necessary throw off velocity, which had been reduced during the preceding cycle. At a suitable instant, as allowed by the stop 28, the door 23 opens under the action of the cam 30, and the carrier starts along the linear throwing portion 17 emerging at a very high speed from the structure 13. Facing the latter, there is a weft thread 8, suction drawn by the vacuum nozzle 38 and arranged in the very path of the carrier which then catches the weft thread in its movement, as explained hereinafter. The carrier then passes through the eyelets 43 entraining the weft thread. On emerging from the shed, before the carrier reaches the entry 50 of the guide 4, the weft thread is cutt off on one side by the cutting device 9, while the end on the other side is released from the carrier in a manner to be explained owing to the action of a device shown schematically at 51. The free end of the thread unwound from the spool 37 is suction drawn by the vacuum nozzle 38 and is caused to be positioned at a pick up position for the next insertion of the weft.
The carrier 3, after leaving the weft thread, enters the portion 4a of the guide and is progressively deviated without being stopped entirely, thereby it continues in its movement with an energy only slightly smaller than the throwing energy, the difference being due to the losses occurring during the entrainment of the weft thread. The carrier 3 continues its stroke through the linear return portion of the guide 4 and re-enters, still at very high speed, the circular guide 16. Here it is reached by the flywheel pawl 20, which rotates faster, i.e. at the throwing peripheral speed. The carrier is then brought once again to the throwing speed level after one or more revolutions of the flywheel 15, with a very moderate consumption of energy, since the carrier has retained most of its energy and speed. From now onwards, a new throwing step or cycle takes place, as described. The resilient arrangement of the pawl 20 prevents damage in the event that the carrier enters the guide 16 at the very moment the pawl 20 passes by.
A carrier effective to engage the weft thread and release it while moving, as required by the device described hereinabove, is shown in FIGS. 8 to 11. It comprises, in the example illustrated, a gripper with two arms 52,53 journaled at 54 and so shaped as to define a thread entering recess 55 in the forward portion, a clamp between the adhering surfaces 56,57 and a following widening 58. A stop member 59 is provided at the rear end, which is mounted pivotally to one of the arms, preferably the upper one 52, and presents a shaped end which matches the rear end of the other arm 53, whereby the gripper is normally held closed and prevented from opening. The weft thread 8 is caused to enter the entering recess 55 during the gripper movement and remains locked therewithin since it tends to wedge into the apex wherefrom the adhering walls 56,57 originate.
In order to open the gripper and release the thread a longitudinal groove 60 is provided in the gripper arm locked by the stop member 59, said groove extending along the arm length up to the end engaged by the member 59. That groove is entered by the obstacle 51 located at the shed end before the entry 50 of the guide 4, which obstacle, on striking the member 59 during the relative movement between the gripper and the obstacle, causes said member 59 to swing to the position shown in FIG. 11, allowing the arms 52,53 to open and to release the thread. Said release action is also facilitated by the provision of the widening 58. As visible in FIG. 1, the obstacle 51 is very near to the entry 50 of guide portion 4a so that when the obstacle 51 engages the member 59 the gripper carrier 3 has already entered the guide portion 4a and can no more be deviated out of its path. The opening of the two arms 52,53 may be made automatic by reason of the location of the pivot point 54 between the gripper center of gravity and the rear part of the gripper, or may be favored by a light torsion spring intervening between the two arms.
The invention just described is susceptible of numerous modifications and variations, all of which fall within the inventive concept. Thus, for example, a plurality of consecutively operating carriers may be provided. In fact, while one of the carriers is being accelerated by the assembly 6 another may insert the weft thread and a further one may return to the assembly 6, the number of consecutively operating carriers depending principally from the size of the loom. An accelerating device may also be provided in the return portion before the assembly 6 at the arcuate guide portion 4a. In addition, between the spool 37 and thread guide 7, a thread supply may be provided so as to reduce the tractive effort on the thread during the entrainment thereof by the carrier, or possibly in order to avoid too sudden a tearing action as the moving carrier picks up the thread. Furthermore, the thread could be supplied to the carrier already within the guide 16, e.g. by feeding the thread through the flywheel shaft and the entrainer 20, in which case the thread would be attached to the carrier at its tail portion, as provided by the Sulzer looms. The guide 4 may, obviously, have a cross-section configuration different from the one shown herein. The door 23 control may also be different from the one described hereinabove, for instance electromagnetic, responsive to a flywheel revolution counter or tachometer device.
|
A shuttleless loom having at least one weft thread carrier movable across the whole shed for inserting a weft thread between the warp threads, and a device for throwing and recovering the weft thread carrier. The device comprises a guide for returning the carrier which has passed across the shed to the throwing position without stopping it and means such as a flywheel for accelerating the returned carrier to confer to it the initial throw speed. The flywheel defines the inner wall of a circular guide portion tangent to a throwing and a returning portion of the guide and has means for entraining the thread carrier. A controlled throw door causes the accelerated carrier to be timely thrown out of the circular guide portion for catching the weft thread and inserting it between the warp threads.
| 3
|
RELATED PATENT APPLICATION
[0001] This application is related to US patent application docket number ATC 03-001, Ser. No. 10/659,633, filed on Sep. 10, 2003, assigned to the same assignee as the present invention, which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to ceiling panels and in particular to ceiling panels placed over and capable of being attached directly an existing ceiling or wall surface.
[0004] 2. Description of Related Art
[0005] Many homes and businesses use ceiling panels as a way to add lighting, acoustic absorption and decoration. There are many ways to attach the ceiling panels, but most require a mechanism to be attached to the ceiling or ceiling joists to which the ceiling panels are, or can be, attached. Some application of ceiling tile require plywood or equivalent, strips of wood or metal rails and/or channels, to first be attached to the ceiling, and then the ceiling tile is attached to the strips of wood or the plywood. In other applications a hanger mechanism is attached to the ceiling upon which the ceiling tile is suspended below the original ceiling. These mechanisms add difficulty and expense to the installation of ceiling tile and can define the limits of the design of the tile.
[0006] U.S. Pat. No. 3,936,990 (Garrison Jr. deceased et al.) is directed to a suspended ceiling using grid members and interlocking clips. U.S. Pat. No. 3,950,916 (Kasprzak) is directed to a unique clip to support suspension members for ceiling panels. U.S. Pat. No. 4,117,642 (Eckert et al.) is directed to a clip structure to hold together ceiling panels. US Des. 421,897 (Wasecheck et al.) is directed to a ceiling panel hold down clip. U.S. Pat. No. 4,437,287 (Halfaker) is directed to rectangular metal ceiling panels having separated perforate and imperforate faces. U.S. Pat. No. 4,480,360 (Brugman et al.) is directed to a clip for mounting a wall or ceiling panel structure. U.S. Pat. No. 4,580,382 (Judkins et al.) is directed to a ceiling attachment member for attaching flanged ceiling panels. U.S. Pat. No. 4,599,831 (Magaha, Jr.) is directed to a device for securing ceiling panels to a T-bar support. U.S. Pat. No. 4,781,005 (Rijnders) is directed to an adapter for use with a support grid for ceiling elements. U.S. Pat. No. 4,858,409 (Handley et al.) is directed to a support member for supporting ceiling panels along its length. U.S. Pat. No. 4,884,383 (Rijnders) is directed to a support grid for ceiling elements. U.S. Pat. No. 4,951,443 (Caferro) is directed to a panel and clip constriction for attaching ceiling panels. U.S. Pat. No. 5,191,743 (Gailey) is directed to a concealing trim assembly for wall or ceiling panel systems. U.S. Pat. No. 5,202,174 (Capaul) is directed to a ceiling panel structure comprising a glass fiber ply, a gypsum board and a perforated vinyl lamina. U.S. Pat. No. 5,253,463 (Witmyer) is directed to safety mechanisms to prevent kerfed ceiling panels from falling. U.S. Pat. No. 5,428,930 (Bagley et al.) is directed to a concealed suspension ceiling system using a T-bar grid network and butterfly clips. U.S. Pat. No. 5,507,125 (McClure) is directed to plastic ceiling panels mounted in a grid of T-rails. U.S. Pat. No. 5,535,566 (Wilson et al.) is directed to a concealed suspension ceiling system using a T-bar grid network. U.S. Pat. No. 5,878,541 (Gruber) is directed to a ceiling construction for reinforced concrete ceilings. U.S. Pat. No. 6,079,177 (Halchuck) is directed to a ceiling panel assembly that connects directly to ceiling joists. U.S. Pat. No. 6,108,994 (Bodine) and U.S. Pat. No. 6,230,463 (Bodine) are directed to a suspended ceiling panel that conceals the suspension system. U.S. Pat. No. 6,155,764 (Russo) is directed to a support mechanism for wearing on the torso and for raising into place a ceiling panel such as sheet rock. U.S. Pat. No. 6,208,733 (LaLonde) is directed to a direct mount grid for mounting ceiling panels close to a mounting surface. U.S. Pat. No. 6,467,228 (Wendt et al.) is directed to a hinged ceiling panel. U.S. Pat. No. 6,499,262 (Pinchot et al.) is directed to an acoustical ceiling panel for a suspended ceiling.
[0007] Attaching ceiling panels to an existing ceiling can be a time consuming effort to install the necessary structure and hardware by which the panels are attached or suspended below the existing surface of a room. A design and method that would allow panels to be attached directly to a room surface will greatly reduce the installation time and expense. The major problem is that sheet rock forms most existing room surfaces, and sheet rock has a limited capability to support weight. Spreading the attachment technique over the entire ceiling provides a way of using the limited strength of the sheet rock and allows a plurality of decorative ceiling panels to be installed and remain attached without falling to the floor.
SUMMARY OF THE INVENTION
[0008] It is an objective of the present invention Is to form a decorative panel of moderate size that can be attached to the surface of a room and interlocked with the adjacent decorative panel to form a contiguous pattern.
[0009] It is also an objective of the present invention to form the decorative panel from a sheet of metal.
[0010] It is still an objective of the present invention to form a decorative panel from any material that can be shaped to form a panel that is directly attached to the surface of a room and interlocked with additional adjacent decorative panels that are subsequently attached directly to the room surface.
[0011] It is also still an objective of the present invention to attach a first decorative panel directly to an original room surface, made of sheet rock ceiling or any other building material forming a flat room surface with screws and obscure the screws from view with adjacent decorative panels that are interlocked with the first panel, hiding the screws from view and subsequently attaching to the original room surface with screws.
[0012] It is further an objective of the present invention to first attached the decorative panels in a row along a first edge of a surface and then attach additional decorative panels along a second edge of the surface perpendicular to the first edge interlocking adjacent decorative panels to obscure mounting screws from view and making a contiguous decorative design.
[0013] In the present invention a decorative panel is formed from a metal sheet, or any other material that can be subsequently formed, by pressing a design into the material of the sheet. The starting sheet of material is approximately twenty-seven inches square with corners that have been cut off and with holes for screws punched into the sheet along two adjacent edges. These two adjacent edges become female flanges when forming of the metal sheet is complete. The other two adjacent edges form male flanges that will help support the finished decorative panel when the male flange is inserted into the female flange which is mounted on a room surface such as a ceiling.
[0014] The corners of the metal sheet are cut at an angle approximately forty-five degrees to allow the flange areas on all four sides located beyond a decorative pattern area to be formed. A decorative pattern is formed in an area at a distance from all four edges of the starting sheet. When using a metal material a decorative pattern is formed by pressing the sheet of metal between a female die, or mold, and a male die, which also begins the formation of the edges that provide two female and two male flanges. The area on the outer extremities of the metal sheet beyond the decorative pattern area are pressed down toward the back side of the decorative panel by the press along the sides of the male die forming an “L” shaped bend. After removal from the die, the outer portion of female flanges are bent back upward hinging at the base of the “L” and forming a “V” shape. In the final flange bend the “V” shaped flange is bent back under the decorative panel, and the “V” is pressed together such that the opening of the “V” becomes narrow and held slightly open by two elongated dimples running the length of female flanges to allow joining to a male flange on an adjacent decorative panel. One leg of the “V” extends beyond the area of the decorative pattern upon which are located the holes that will be used to hold the decorative panel to a ceiling. The flange areas comprise a female and a male flange that are formed on opposite edges of the decorative area where along two adjacent edges of the decorative panel female flanges are formed and along the two remaining adjacent edges male flanges are formed. The female flanges extending beyond the area of the decorative design contain holes for mounting screws. The male flanges extending beyond the area of the decorative design have a smooth surface of the original sheet of material and are inserted into the female flange of an adjacent decorative panel to help hold the panel to which the male flange is attached to the room surface. The female flanges are folded in three folds to form the female flange that comprises a portion under the decorative design area to receive the male flange, and a portion extending beyond the decorative area containing mounting holes for attaching the decorative panel to a room surface. The male flanges are folded in one folding step to produce an “L” shaped male flange that protrudes outward from the decorative area and mates with the female flange of adjacent decorative panels when being attached to a room surface. The male flange slips into the female flange over the heads of the mounting screws holding the panel with the female flange to the room surface and obscuring the mounting screws from view.
[0015] The decorative panels are first installed in a first column, running along one edge of an area on the surface of a room with a first panel located at a corner of the area that is to receive the decorative panels, where the female flanges are oriented away from the corner in the direction of the remaining area. Each decorative panel is held in position by six screws, three along each edge of the female flanges. If the original surface is created from a building material called sheet rock, the screws are of a type particularly suited for the sheet rock material. A second decorative panel is positioned adjacent to the first panel in the first column such that a male flange is positioned into the female flange, and the decorative areas of the first and second panel are butted together, obscuring the mounting screws and forming an extended decorative pattern along the first column. Then the second decorative panel is attached to the room surface with six screws, using three mounting holes located in each of the two female flanges of the second decorative panel. Subsequent panels are attached to the room surface in the first column in a similar fashion. The mounting process continues in the first column until the first column is completely populated with the decorative panels.
[0016] A first row is formed along a second edge of an area on the surface of a room perpendicular to the first column producing an “L” shape. A third decorative panel is positioned next to the first panel in the first row with a male flange of the third panel positioned into the female flange of the first panel, obscuring the heads of the mounting screws holding the first panel to the room surface. The first and third panels are butted together forming an extended decorative pattern along the first row. Then the third decorative panel is attached to the room surface using six mounting screws, three each in the holes of the two female flanges. Subsequent decorative panels are attached in the first row in a similar fashion, extending the decorative pattern to the end of the first row.
[0017] Subsequent columns and rows adjacent to the first column and row are populated with additional decorative panels by mating male and female flanges and fastening each panel to the surface of the room directly with screws. This process of populating the area of a surface of a room with decorative panels continues until a last panel is positioned and fastened to the surface of the room.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] This invention will be described with reference to the accompanying drawings, wherein:
[0019] FIG. 1A is a diagram of the present invention showing a prepared sheet of material ready for forming;
[0020] FIG. 1B is a diagram of the present invention of a sheet of material with a pressed design thereon;
[0021] FIG. 2A is a diagram of the present invention showing the partial formed female edges after a first bending operation;
[0022] FIG. 2B is a diagram of the present invention showing the formed male edges;
[0023] FIG. 3 is a diagram of the present invention showing the partial formed female edges after a second bending operation;
[0024] FIG. 4A is a diagram of the present invention showing a formed decorative panel;
[0025] FIG. 4B is a cross section of the formed decorative panel showing an edge containing a male flange;
[0026] FIG. 4C is a cross section of the formed decorative panel showing an edge containing a female flange;
[0027] FIG. 5A is a diagram of the present invention showing the population of an area within a room with decorative panels; and
[0028] FIG. 5B is a diagram of the present invention showing the mating of a male and female flange and the attachment of the female flange to a surface of a room.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] In FIG. 1A is shown a sheet 10 of tin-plated alloy steel used to form a decorative panel of the present invention. The sheet measures approximately twenty-seven inches square and contains punched holes 11 on two adjacent sides designated as female sides of the panel. The holes are used in attaching a finished decorative panel to surface of a room. Opposite the female sides are edges designated as male sides 15 . Within the sheet is shown an area 12 in which a decorative design is to be formed. The decorative design area is approximately two feet square and offset from the center of the sheet by approximately one half inch in each the “x” and “y” directions. The corners 13 are cut at an angle of approximately forty-five degrees and are positions so that the cut for each corner is tangent to the respective corner of the area 12 . The edges containing the punched holes 14 are formed into female flanges that attached the decorative panel to a surface. The edges without holes 15 are formed into male flanges, which mate with female flanges of adjacent decorative panels.
[0030] In FIG. 1B is shown a sheet of tin plated alloy steel 20 after a decorative pattern 21 has been formed into the sheet using a press with a female die, or mold, and a male die. Two elongated dimples, or protrusions, 22 are formed on the two female sides 14 , which contain the punched holes 11 . The elongated dimples, or protrusions, are used to allow easy insertion of a male flange of an adjacent decorative panel into a female flange of the completed decorative panel by keeping a folded female flange slightly open. A view of the corner where the two female sides 14 come together is shown in FIG. 2A and a corner view of the joining of the two male sides is shown in FIG. 2B .
[0031] In FIG. 2A is an isometric view of the corner 30 where the two folded female sides 14 ( FIG. 1B ) come together after the first fold 24 of the area on the panel that contains the two female edges. In this first fold, the female edges form an “L” shape The panel 20 containing the formed decorative pattern 21 is shown resting on the male die 22 of the press. In FIG. 2B is shown the corner 31 where the two male sides 15 ( FIG. 1B ) come together again forming an “L” shaped male flange 25 . The vertical leg of the “L” is much shorter than that of the vertical leg for the female edges 24 in FIG. 2A .
[0032] In FIG. 3 is shown a second fold of the female edges 34 into an inverted “V” shape. Behind the second folded female edges is the area of the backside of the formed decorative pattern 35 . The outer leg of the inverted “V” 36 is longer than the inner leg, which will allow the punched holes 11 to be exposed after the final fold so that the holes can be used to mount the finished decorative panel. The area 37 of the fold requires a cutting away of a slight amount of material so that the two female flanges that are formed in the final fold come together properly and are able to receive a mating male flange from adjacent decorative panels when assembled together on a surface of a room, i.e. a ceiling or a wall.
[0033] In FIG. 4A is shown the final formed decorative panel 50 . The female sides 36 ( FIG. 3 ) are folded under the back of the area containing the decorative pattern 51 . The “V” shaped female edges 36 are pressed together creating a narrow opening to receive a male flange 25 ( FIG. 2B ) and permitting the punched holes 11 to be exposed. In FIG. 4B is shown a cross section of the male flange 35 and a potion of the area of the decorative pattern 51 . The vertical edge of the “L” shaped male flange has a length that aligns the foot of the “L” shape with an opening in the female flange 52 . FIG. 4C shows a cross section of the final folded and pressed together shape of the female flange 52 . A mounting hole 11 is shown in the in the expose leg of the female flange 52 along with the dimples, or protrusions, 22 that extend the length of the flange to keep the female flange slightly open. After the final fold when the mechanical processing of the decorative panel is completed, the panel is coated, for instance by electro static painting, which is heat dried before being assembled together with additional decorative panels on a surface.
[0034] In FIG. 5A is a diagram of the present invention showing the mounting of a plurality of decorative panels 72 onto a surface of a room. Each of the panes has a lower male flange 35 b , a left male flange 35 a , an upper female flange 52 a and a right female flange 52 b . The surface of the room has a grid, either imaginary or laid out by a chalk string, or equivalent, with columns C 1 to Cn and rows R 1 to Rm. The decorative panels, hereafter called panels, are first positioned, mated with adjacent panel previously installed and connected to a room surface (ceiling or wall) in an “L” shaped pattern starting in a first column C 1 and a first row R 1 at the outer edge of the area that is to be covered with the panels. Either the first column C 1 or the first row R 1 can be populated first starting at the corner position, C 1 and R 1 . Any corner of the area can be the starting position, but for purposes of the description herein the starting position is designated as the lower left corner of FIG. 5A .
[0035] A first decorative panel 62 is position in the corner formed by column C 1 and row R 1 with the female flanges pointing towards the area to be populated. Once the first decorative panel is positioned, the panel is fastened to the room surface with screws or other suitable mounting mechanisms. If the surface of the room is made of sheet rock material, then sheet rock screws are used to fasten the panel through the exposed holes in the female flanges. As described herein, each female flange 52 a and 52 b has three mounting holes 11 ; however, there maybe a greater or fewer number of holes needed to be used to attach the panels to a surface, for instance if the surface was a strong material such as wood, then one or two screws or other suitable fastening mechanisms might be used to attach the panels.
[0036] Once the first decorative panel 62 has been positioned and fastened to the room surface, a second panel 63 in C 1 and R 2 is mated with the first panel 62 by aligning the second panel 63 with the first panel 62 and inserting lower male flange of panel 63 into the upper female flange of panel 62 The two panels 62 and 63 are butted together eliminating any discernable gap between the two panels and covering the fastening mechanisms used for panel 62 . Panel 63 is then fastened to the material forming the surface in a fashion similar to the first panel 62 . The next panel is positioned either above the second panel 63 in C 1 or to the right of panel 62 in R 1 . Herein it is assumed for illustration purposes that the next panel 64 is positioned above panel 63 , aligned and mated with panel 63 and mounted to the surface in a similar fashion as described for panel 63 mating with panel 62 . The important part of the initial population of the area 60 is to first populate the first column C 1 and the first row R 1 before any additional columns and rows are populated to allow the mounting holes of each panel to be accessible for fastening a panel to the material forming the surface upon which the panels are being assembled.
[0037] The column C 1 is populated with additional panels in like fashion as describe for panels 62 and 63 until a final panel 65 is positioned and fastened to the surface. Then panel 66 is position in the first row R 1 to the right of panel 62 , mated with panel 62 by inserting a left male flange of panel 66 into the right female flange of panel 62 , butting the two panels 66 and 62 together to eliminate any discernable gap, covering the fastening mechanisms in the mounting holes in panel 62 and fastening panel 66 to the surface using the punched holes in the two female flanges 52 a and 52 b of panel 66 . Outer row R 1 of the area 69 is populated with additional panels in a similar fashion as used for panel 66 , until the final panel 67 in column Cn is positioned and mated with the panel to the left in row R 1 and fastened in place.
[0038] Continuing to refer to FIG. 5A , next a panel 68 is positioned into column C 2 and row R 2 where the left male flange 35 b of panel 68 is inserted into the right female flange 52 b of panel 63 , and the lower male flange 35 a of panel 68 is inserted into the upper female flange 52 a of panel 66 . Panel 68 is aligned with panels 63 and 66 , butting panel 68 against panels 63 and 66 to eliminate any discernable gaps, covering the fastening hardware in panels 63 and 66 , and fastening panel 68 to the surface material. Then panel 69 is positioned, aligned and butted against panels 64 and 68 , where the left male flange 35 b of panel 69 is inserted into the right female flange 52 b of panel 64 , and the lower male flange 35 a of panel 69 is inserted into the upper female flange 52 a of panel 68 . Column C 2 is populated with panels using a similar procedure as used for panel 69 , and when column C 2 is populated row 2 is populated.
[0039] Panel 71 is positioned into C 3 and R 2 , aligned, mated and butted against panels 68 and 70 , where a left male flange 35 b of panel 71 is mated with a right female 52 b of panel 68 and a lower male flange 35 a of panel 71 id mated with a upper female flange 52 a of panel 70 . Panel 71 is then fastened to the material forming the surface of the area 60 . The population of the surface area 60 with panels continues until the last panel 72 in column Cn and row Rm has been position, aligned, and mated with the adjacent panels, and the last panel 72 is fastened to the material forming the surface of the room.
[0040] In FIG. 5B is shown a cross section of a mating of a male flange 90 of a panel 70 ( FIG. 5A ) to a female flange 92 of panel 66 . The female flange 92 is fastened to a material 95 forming the surface upon which both panels 66 and 70 are being fastened. Prior to the mating of panels 66 and 70 , the female flange 92 of panel 66 is formed into a closed “V” shape where one leg of the “V” longer and is used to allow fastening panel 66 to the building material 95 using a screw in this example. If the material is sheet rock, the screw is a sheet rock screw or equivalent. There are shown two elongated dimples (protrusions) 96 , which run the length of the female flange that hold open, slightly, the “V” shape of the female flange to allow the insertion of the male flange 90 formed as part of panel 70 . The male flange 90 is formed into an “L” shape and has a smooth surface free of protrusions or perturbations similar to the elongated dimples 96 of the female flange 90 .
[0041] 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 various changes in form and details may be made without departing from the spirit and scope of the invention.
|
A decorative panel, method of manufacture and installation on a surface of a room is described. The decorative panel is formed from a material that can shaped having a decorative portion, two female mounting portions and two male portions. The female portions have punched holes for fastening the panels directly to a surface, and the male portions of an adjacent panel are position into the female portions to partially hold the adjacent panel and to obscure from view the punched holes and fastening hardware. The panel design and installation method allows the decorative panels to be attached directly to a building material such as sheet rock without any intervening supporting structure.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of priority to U.S. Provisional Application Ser. No. 60/722,847, filed on Sep. 29, 2005, the contents of which are incorporated herein by reference.
BACKGROUND
Apoptosis is a genetically regulated mechanism for programmed cell death, which is important from embryogenesis throughout adult life. It eliminates cells that are not useful to the multicellular organism by mechanisms that are distinct from the mechanisms that kill cells due to injury, anoxia, etc. Apoptosis is initiated by a signal to the cell, which activates a cascade of reactions involving various protein factors and proteolytic enzymes. The very specialized proteases involved, called caspases, are normally present in proenzyme form, and are activated by a cleavage mechanism. They then hydrolyze specific proteins, which initiates disassembly of the cell. Textbook of Biochemistry with Clinical Correlations, 5 th ed., pg. 23 (Thomas M. Devlin, ed., Wiley-Liss (2002)).
Different types of cells have different receptors that can be stimulated to initiate apoptosis; the specificity of these receptors is obviously critical to the survival of an organism, because it determines which cells survive and which die. Dysfunctions in the apoptosis machinery are associated with a variety of disorders including immune disorders, inflammatory conditions, malignancies, neurodegenerative diseases, and viral infections that affect the immune system. Id. See also TNF, Apoptosis and Autoimmunity. A Common Thread? , B. Beutler and F. Bazzoni, Blood Cells, Molecules, and Diseases, 24(10), 216-30 (1998) (electronic journal, available online at http://www.scripps.edu/bcmd/).
Apoptosis has been described as a systematic process for eliminating unneeded or defective cells to maintain balance. C. B. Thompson, Science , vol. 267, 1456-61 (1995). Thus apoptosis provides a mechanism which could also be useful to eliminate defective cells such as malignancies if it could be selectively triggered in those cells. Tumor necrosis factor (TNF), a cytokine which selectively initiates apoptosis in tumor cells, demonstrated that treatment of cancer could in theory be accomplished with this approach, and efforts related to TNF continue, often focused on ways to control production of cytokines.
A substance referred to as T4 immune stimulating factor (TISF) has been identified and described recently due to its immune-stimulating activities. U.S. Pat. No. 5,616,554. TISF is alternatively referred to as Epithyme™ and as S-Celergin at times herein and in other references. It is one of a number of factors that have been described which stimulate various stages of CD4+ lymphocyte development. TISF stimulates a normally unresponsive population of cells at a later stage of the development process, while a different factor stimulating an earlier stage of the process is described, for example, in Beardsley, et al., PNAS 80: 6005 (1983).
TISF is a polypeptide that is typically glycosylated. It “stimulates, enhances or regulates cell-mediated immune responsiveness” by stimulating mature T-lymphocytes as described in U.S. Pat. No. 5,616,554. It is thus able to enhance the immune response of animals to infectious agents and to some malignancies. Id. In addition, TISF has been reported to promote hematopoiesis, or blood cell development, possibly by its ability to stimulate CD4+ lymphocytes. U.S. application Ser. No. 10/938,451. Thus in cats having feline immunodeficiency virus or feline leukemia virus infections, treatment with TISF increased lymphocyte counts, and also increased red blood cell, platelet and granulocyte levels. Id.
Cytokines, broadly defined, are cell-derived hormone-like peptides that regulate cellular replication, differentiation, or activation related to defense and/or repair of the host organism. Thus based on its activities described above, TISF may be considered a cytokine, like interferon, TNF, and the interleukins. However, as described in U.S. Pat. No. 5,616,554, TISF is distinct from the known cytokines.
Surprisingly in light of its ability to stimulate hematopoiesis, it has now been found that TISF is also capable of initiating apoptosis in some cell populations, including certain types of blood cells. In particular, it has been found that TISF selectively causes cell death or cessation of tissue growth in aberrant T-cells, such as lymphoma cells, lymphocytes that carry HIV virus, and leukemic cells. While reported to be capable of stimulating an immune response that could in theory target malignant cells, see U.S. Pat. No. 5,616,554, it is surprising to find that TISF can cause cell death selectively in compromised T-cells in the absence of any immune response, as demonstrated by in vitro experiments.
The present invention relates to methods of using TISF to treat disorders characterized by production, development, or activity of aberrant T-cells. Because it operates by a mechanism independent of the stimulation of the immune response previously associated with TISF, it provides methods to treat such conditions in immune-compromised individuals where a treatment relying on stimulation of the subject's immune response would not be expected to work well. For example, it is especially well suited to the treatment of subjects having an immune disorder such as HIV and treatment of subjects who are concurrently receiving immune-suppression drugs.
Each reference cited herein is incorporated by reference in its entirety. No citation of any document is an admission that such document constitutes prior art to this application.
BRIEF SUMMARY OF THE INVENTION
The present invention provides methods for treating disorders characterized by production, development, or activity of aberrant cells of hematopoietic origin, and especially of aberrant leukocytes or T-cells. While not limited by any theory of how the methods operate, the invention originated in the discovery that TISF stops growth of and induces apoptosis in aberrant T-cells. Aberrant T-cell disorders include those where T-cells have become malignant or infected with a virus. Apoptosis is selectively triggered in such T-cells by treatment with TISF or a peptide related to TISF (herein referred to as a TISF peptide). Thus TISF or TISF peptides and compositions comprising such peptides are useful for the treatment of these disorders, which include a variety of T-cell lymphomas like mycosis fungoides, T-cell leukemias, and some viral infections like HIV that are harbored by T-cells. Typically, the TISF is obtained in substantially pure form from a mammalian tissue or cell, as by culturing a mammalian cell followed by extracting the TISF or TISF peptide and using conventional methods to purify the TISF or TISF peptide. In certain embodiments, TISF is produced by a thymic cell culture, and TISF peptides are often prepared by modifications of TISF from such cultures, typically by selective proteolysis.
The invention also includes pharmaceutical compositions comprising TISF or a TISF peptide, preferably in substantially pure form, in combination with at least one pharmaceutically acceptable excipient. It further includes methods for the preparation of a medicament for the treatment of disorders characterized by aberrant production, development, or activity of T-cells or other cells of hematopoietic origin, where such medicament comprises TISF or a TISF peptide.
The invention also provides methods to induce apoptosis in an aberrant lymphocyte by contacting the aberrant lymphocyte with TISF or a TISF peptide. The lymphocyte may be contacted with TISF or a TISF peptide ex vivo or in vivo, and in many embodiments, the lymphocyte is contacted with TISF or a TISF peptide in vivo, often in a human or other mammal. The subject may be one diagnosed with a T-cell lymphoma such as those described herein, or with a T-cell leukemia, or it may be a subject diagnosed with HIV, wherein the aberrant hematopoietic cells are those containing HIV virus.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the rate of growth of CTCL tumors using the mouse xenograft CTCL model system in mice receiving a single dose of TISF as described in Example 5.
FIG. 2 shows the rate of growth of CTCL tumors using the mouse xenograft CTCL model system. The squares represent an untreated control, while the diamonds represent growth rate of tumors in mice receiving several doses of TISF per week as described in Example 6.
FIG. 3 shows the body weight for the control and treated mice from Example 6.
FIG. 4 shows the rate of tumor growth (Tumor volume) for CTCL tumors in the mouse xenograft model, using the supernatant from a TISF producing cell culture (“TPA supernatant”) and using a partially purified sample of TISF (“TPA purified”), demonstrating that the cell culture supernatant has a tumor growth-suppression effect, while the purified TISF composition has a much greater growth-suppression effect. The tests were performed according to Example 5, and the dates indicate when tumor volume was assessed following an initial treatment with TISF or the supernatant.
FIG. 5 shows the rate of tumor growth (Tumor volume) for CTCL tumors in the mouse xenograft model using a composition containing a partially purified TISF (identified as TPA) at two different concentrations: “TPA 10×” (the dashed line) represents a ten-fold higher TISF concentration than TPA (squares). Both concentrations have an effect on tumor growth for at least several weeks after administration of TISF, and the response is dose dependent. The tests were performed according to Example 5, and the dates indicate when tumor volume was assessed following an initial treatment with TISF.
FIG. 6 summarizes the histological examination of each of the mice used in the experiment described in Example 6.
FIG. 7 shows histological images of tumor tissue from representative mice from the experiment described in Example 6.
DETAILED DESCRIPTION OF THE INVENTION
TISF is described as a 50 kD protein with an isoelectric point of 6.5, which may be glycosylated. It is also sometimes referred to as S-Celergin, and a product referred to as “Thymic Protein A”, which is a thymus cell culture extract, reportedly contains TISF. Methods for the production and isolation of TISF that are applicable to preparation of TISF from a mammalian species are described in U.S. Pat. No. 5,616,554.
As used herein, the term “TISF” refers to a protein having the physical and biological properties of a TISF proteinaceous substance as described in U.S. Pat. No. 5,616,554. The substance may be obtained for instance by isolation from thymic tissue of cells of a mammalian species such as bovine, ursine, equine, feline, canine, murine, or human. U.S. Pat. No. 5,616,554 provides methods for producing and characterizing TISF from a culture of thymus cells obtained from the appropriate mammalian species, and is incorporated herein by reference in its entirety.
As used herein the term “mammalian TISF” refers to a protein that has the physical and biological properties of TISF found in a mammalian species, without regard to how the protein was actually obtained. Thus, for example, the TISF obtained from a cell culture is included within the scope of the claims provided it has the same biological and physical properties as that found in a mammalian species. Similarly, “human TISF” refers to the peptide having the physical and biological properties of TISF found in humans, and is not limited to TISF that was obtained from a human.
As used herein, the term “TISF peptide” refers to a polypeptide or glycosylated polypeptide obtainable by partial hydrolysis or proteolysis of a protein referred to as TISF in U.S. Pat. No. 5,616,554, provided the material retains at least 20% of the activity of TISF from a mammalian species, as measured by the mouse xenograft model described herein.
TISF has been found to inhibit growth of aberrant cells of hematopoietic origin. These aberrant cells include cells that lack normal growth regulation means, and cells that are compromised by an infecting virus or detrimental mutation. TISF, and TISF peptides, inhibit the growth of such aberrant cells and thereby alleviate symptoms associated with the production, activity or development of such aberrant cells.
TISF has been shown to inhibit cell growth in a culture of lymphoma cells in a dose-dependent manner, as demonstrated by 3 H-thymidine incorporation experiments. It was also shown to increase cell death rate among lymphocytes infected with the HIV virus. In such cells, TISF also slowed the production of virus. Furthermore, when cells of human myelomonocytic leukemia cell line K562 were treated with TISF, the level of apoptosis in that cell culture increased by more than two-fold over a control. By comparison, TISF exerted no effect on growth rate of the cells of a non-lymphoid malignant cell line, demonstrating that the effect on lymphoma cells is not a general cytotoxic effect, nor is it attributable to a systemic immune response induced by TISF.
TISF has also been tested for its effect on a cutaneous T-cell lymphoma (CTCL), using a mouse xenograft model described by T. S. Burger, et al., in Experimental Dermatology , vol. 13, 406-12 (2004). Cutaneous T-cell lymphomas (CTCLs) are a group of lymphoproliferative disorders involving the skin. The most common form is mycosis fungoides (MF), in which malignant growth of T-cells occurs in the form of patches and later tumors on the skin. Id. Burger, et al., discloses a method for growing human MF tumors in immune-deficient nude mice, and demonstrates that the malignant cells spread to the lymph nodes, blood stream and other organs. Using this model system, it has now been shown that TISF dramatically slows the growth of a CTCL tumor. The effect becomes apparent within days after administration of a dose of TISF, and the effect of a single dose continues for at least two weeks during the rapid growth phase of the model tumor, as shown in FIG. 1 .
These data indicate that malignant cells and virus-infected cells of lymphoid or myeloid origin are induced by TISF to initiate apoptosis, and that the effect can be achieved in vivo as well as in vitro. This biological activity of TISF may usefully be applied to the treatment of a variety of disorders which are characterized by aberrant T-cells or other aberrant cells of hematopoietic origin. Such disorders include various lymphomas involving T cells, including adult T-cell lymphoma, Precursor T-cell lymphoblastic lymphoma, extranodal natural killer T-cell lymphoma, enteropathy T-cell type lymphoma, hepatosplenic T-cell lymphoma, subcutaneous panniculitis like T-cell lymphoma, mycosis fungoides or cutaneous T-cell lymphoma (CTCL), Sezary syndrome (the leukemic phase of CTCL), anaplastic large cell lymphoma, peripheral T-cell lymphoma, and angioimmunoblastic T-cell lymphoma. Additional disorders treatable by the methods and compositions described herein include certain leukemias, such as childhood leukemia of T-cell origin, adult T-cell leukemia, lymphocytic leukemia, chronic T-cell leukemia, myeloid leukemia, and erythroid leukemia. These disorders also include those viral conditions where lymphocytes are infected, and specifically HIV infection is included. TISF may benefit subjects having HIV in other ways, too, because of its immunostimulatory effects and promotion of hematopoiesis, but the present invention provides a method to induce apoptosis of the aberrant T-cells and thus reduce viral load for HIV patients.
In the case of HIV, treatment with TISF may be used to reduce the direct effects of the disease, to slow its progression, or to reduce its transmissibility, since TISF not only slows proliferation of the infected cells but also reduces production of virus. While T-cells infected with HIV are commonly killed by apoptosis caused by immune responses, it has been postulated that those T-cells harboring HIV virus that are not killed may be a critical reservoir for development of the infection. A. D. Bradley, et al., Blood , vol. 96(9), 2951-64 (November 2000). Thus a mechanism to kill those refractory HIV-infected cells might provide a substantial improvement to existing therapeutic protocols.
TISF or a TISF peptide may also be used in ex vivo applications. These ex vivo applications can include in vitro treatment of an aberrant T-cell, such as in a cell culture, as well as extracorporeal treatment of a tissue, cell or sample taken from a subject. The methods and compositions may, for example, be used to treat marrow samples, blood cells, or stem cell products collected for use in transplantation methods, to reduce or eliminate aberrant T-cells from such samples.
TISF may be obtained by purification from a host animal, but is alternatively obtained by purification from a thymic cell culture by methods such as those described in U.S. Pat. No. 5,616,554, which is herein incorporated by reference in its entirety. TISF is obtainable from feline, canine, ursine, equine, murine, or bovine species or from humans; in a preferred embodiment, the TISF is obtained or obtainable from the same species as the species of the subject to be treated. TISF may be used to treat aberrant T-cell conditions in canine, feline, and bovine subjects as well as in human subjects.
TISF peptides may be obtained by partial hydrolysis of or partial proteolysis of TISF using methods well known to those of ordinary skill in the art, such as methods described in D. W. Cleveland, et al., J. Biol. Chem . Vol. 252(3), 1102-1106 (1977) for peptide mapping. Many proteases suitable for partial digestion of peptides are known, and they can be used to partially hydrolyze TISF to produce fragments of TISF referred to herein as TISF peptides. Such fragments are within the scope of the invention provided they maintain at least 20% of the activity of a TISF as described above. Thus the term “TISF peptide” includes peptides obtained or obtainable by partial hydrolysis or partial proteolysis of a TISF from a mammalian species, provided the peptide possesses at least 20% of the biological activity of TISF, and includes TISF peptides obtained from human TISF by partial proteolysis. TISF peptides are preferably at least about 20 amino acids in length, more preferably at least about 40 amino acids in length; and they may optionally include modifications of the amino acids that correspond to those found in TISF such as glycosylations, methylations, lipidations, and the like.
TISF or a TISF peptide may be administered parenterally, intraperitoneally, topically or orally. Parenteral administration is often preferred, and intraperitoneal administration is sometimes preferred. The TISF or TISF peptide may be admixed with pharmaceutically acceptable diluents, excipients, stabilizing agents, solubilizing agents, or other pharmaceutically-indicated agents, and it may optionally be incorporated into a liposomal or slow-release matrix for administration or transdermal delivery. Typically it is delivered by injection of a pharmaceutical composition comprising TISF or a TISF peptide admixed with at least one pharmaceutically acceptable excipient.
Suitable pharmaceutical carriers and diluents, as well as pharmaceutical necessities for their use in pharmaceutical formulations, are described in Remington's Pharmaceutical Sciences (Alfonso Gennaro et al., eds., 17th ed., Mack Publishing Co., Easton Pa., 1985), a standard reference text in this field, in the USP/NF, and in Lachman et al. ( The Theory & Practice of Industrial Pharmacy, 2nd ed., Lea & Febiger, Philadelphia Pa., 1976). In the case of rectal and vaginal administration, the compositions are administered using methods and carriers standardly used in administering pharmaceutical materials to these regions. For example, suppositories, creams (e.g., cocoa butter), or jellies, as well as standard vaginal applicators, droppers, syringes, or enemas may be used, as determined to be appropriate by one skilled in the art. Intravenous, intramuscular, intraperitoneal, or other types of injection administration are often advantageous, for TISF or TISF peptides; suitable compositions for such administration are well known to those skilled in the art, and appropriate excipients may be identified by reference to other polypeptide pharmaceutical compositions.
The compositions of the invention may be administered by any route clinically indicated, such as by application to the surface of mucosal membranes (including: intranasal, oral, ocular, gastrointestinal, rectal, vaginal, or genito-urinary). Alternatively, parenteral (e.g., intravenous (IV), subcutaneous, intraperitoneal, or intramuscular) modes of administration may also be used. Because TISF or a TISF peptide is a polypeptide, and is thus potentially subject to degradation upon oral or topical administration, administration by parenteral (injection) methods including intravenous delivery is often preferred. To maximize its efficient utilization, intravenous delivery of TISF or a TISF peptide is sometimes preferred and such delivery may be concurrent with delivery of other nutrient, hydration or therapeutic agents as appropriate. For intravenous administration, TISF or a TISF peptide is preferably dissolved in an aqueous or isotonic solution such as saline; phosphate buffer may be added as needed to ensure stability of the composition. Further details of compositions suitable for administration of TISF and TISF peptides are well-known to those of skill in the art by reference to other pharmaceutical compositions which contain polypeptides.
The methods of the invention typically include treatment of a subject diagnosed as in need of treatment for an aberrant activity, development or production of a T-cell or cell of hematopoietic origin, wherein the subject is treated with an effective amount of TISF or a TISF peptide. A subject can be diagnosed as in need of such treatment by one of ordinary skill, who can determine whether the subject has aberrant production, development or activity of T-cells or other hematopoietic cells using known methods to evaluate these parameters, or by diagnosing the subject by independent means as a subject having a condition known to include aberrant production, development or activity of such cells. One of ordinary skill can then determine an effective amount of TISF or a TISF peptide by monitoring the subject for improvement in response to an initial dose and determining future dosage levels according to the subject's response to the initial dose, or by using results of such treatment in similar subjects.
The amount of TISF or TISF peptide to be administered depends on the particular subject and indications, and can be determined and adjusted using routine optimization methods. Dosage may be adjusted according to the subject's size or body weight, for example, and may be based on the subject's overall health, as well as other medications or treatments administered to the subject. The mode and frequency of administration can also be determined according to the desired effect, as one skilled in the art will appreciate, and the effectiveness of the chosen regimen can readily be ascertained by monitoring the effect on the targeted hematopoietic or T-cell population, allowing the regimen to be optimized for the particular subject being treated. In general, TISF or a TISF peptide will be administered in compositions which deliver amounts of TISF or a TISF peptide ranging between about 1 μg and 500 mg per kilogram of body weight of the subject. Preferred doses are generally between about 5 μg/kg and 100 mg/kg, or between 10 μg/kg and 50 mg/kg. A dosage of 10 μg/kg to 10 mg/kg is often utilized.
Where the material is not administered in a continuous fashion such as by intravenous drip, administration may be repeated as is determined to be necessary by one skilled in the art, considering the severity of the subject's need for treatment and what other treatments the subject is receiving. In appropriate circumstances, TISF or a TISF peptide may be delivered continuously to a subject via an intravenous fluid delivery system. While a single administration of TISF or a TISF peptide has been demonstrated to produce effects lasting for several days to several weeks, repeated administration at intervals of a few hours to a month are contemplated and are within the scope of the invention. Thus TISF or a TISF peptide may be administered one to three times daily, or it may be administered one to three times per week, or one to two times per month. Determination of the dose required and the frequency of treatment required are within the ordinary skill in the art, since dosage and frequency can be adjusted until the desired effect is achieved. Progress is readily monitored by standard methods for monitoring tumor growth in CTCL, for example, or by methods for monitoring viral load in an HIV patient, for example.
Since TISF or a TISF peptide may be used to treat viral infections such as HIV and a variety of T-cell lymphomas, it is also contemplated that TISF or a TISF peptide may be admixed with or administered with other therapeutic agents appropriate for treating patients having such disorders, including but not limited to antiretroviral agents such as HIV protease inhibitors and reverse transcriptase inhibitors, radiotherapeutic treatments, and antineoplastic therapeutic agents such as alkylating agents, purine nucleoside analogs, and corticosteroids. Compositions containing a mixture of such other therapeutic agents with TISF or a TISF peptide are thus contemplated, as are treatment protocols which utilize TISF or a TISF peptide in combination with such agents. Similarly, such compositions may comprise more than one TISF and/or TISF peptide.
TISF or a TISF peptide may be administered to a subject via various means, including parenteral (especially intravenous delivery), oral, topical and intraperitoneal administration. In some cases, local delivery as by an injection or topical method may be preferred to deliver the active material to a specific location on the subject's body known to need treatment. Methods known to be useful for the administration of peptide therapeutics can be applied. The material can be delivered by suppositories or by implanted slow-release depot methods known in the art where appropriate.
A minimal effective dosage of TISF or a TISF peptide is often about 1 μg/kg of the recipient subject's body weight; preferably, at least about 5 μg per kilogram of the subject's body weight is administered to the animal, with an upper limit of about 500 mg/kg. TISF or a TISF peptide may efficaciously be administered alone or in combination with another immune potentiator, and may be incorporated in a pharmaceutically acceptable carrier or excipient. It may also be incorporated into an isotonic solution for intravenous administration.
The present invention can be better understood by way of the following examples which are representative of certain preferred embodiments thereof, but which are not to be construed as limiting the scope of the invention.
EXAMPLES
Example 1
Lymphoma cells were incubated for 48 hr in the presence of TISF at several different concentrations. The cells were then treated with 3 H-thymidine to measure cell proliferation. At each concentration, TISF inhibited cell growth. As a control to determine whether the effect was a general cytotoxicity, a non-lymphoid malignant cell line was also treated with TISF, and TISF had no effect on the rate of growth in that case.
Example 2
Lymphocytes infected with the HIV virus were incubated with TISF at different doses. Cell death occurred at each concentration tested, and the extent was dose-dependent. Moreover, the concentration of TISF correlated with decreased production of virus.
Example 3
The human myelomonocytic leukemia cell line K562 was incubated with TISF. The rate of apoptosis increased more than two-fold over that in a control culture.
Example 4
TISF may be obtained by the following procedures from U.S. Pat. No. 5,616,554.
A cloned cell line of thymic cells may be established as described herein. For example, in accordance with the present invention, thymic stromal cells of feline origin were established as a continuously replicating, cloned cell line, according to the method described in Beardsley, et al., PNAS 80:6005 (1983), which is incorporated herein by reference. A selection process was used to isolate a cell line producing homogenous TISF.
The same technique has been employed to establish cloned thymic epithelial cell lines from thymic tissue removed from juvenile dogs and calves and from human thymic remnants removed from children undergoing cardiac surgery.
Preparation of Thymic Cell Lines: Briefly, the procedure for reproducibly obtaining the cell lines of the present invention is as follows. Thymus tissue was removed aseptically under general anesthesia. The tissue removed was placed immediately into tissue culture. A primary culture of about 1×10 8 thymocytes was established in a 60 mm Petri dish in 5 ml of DMEM and 20% fetal calf serum. After about 48 hours, the thymocytes were gently washed away and the scattered few adherent cells were fed with 50% fresh DMEM containing 20% fetal calf serum and 50% conditioned medium, obtained after centrifugation of the thymocytes. Primary cultures containing a variety of cell types were maintained by weekly feeding with a similar 50:50 mixture of fresh and conditioned medium. After about four weeks, several isolated colonies of epithelial-like cells covered the plate. At this time, a secondary culture was made by transfer of several of these colonies scraped from the primary culture. Growth tended to be slow until the third subculture, when cells began to form a monolayer within 4-5 days. Cloning of the cells by limiting dilution at one cell per well was less successful than “seeding” the wells with three or four individual cells, which tended to grow to confluency. Single cells plated in limiting dilution were more likely to grow to confluency if epidermal growth factor was added at 6 ng/ml to wells containing single cells.
Clones exhibiting epithelial-like morphology were grown out and the supernatants tested for their ability to enhance alloreactivity in whole thymocyte populations. Supernatants from confluent thymus-derived cultures were tested for their capacity to promote thymocyte functional activity. For example, one such method involved testing the ability of the supernatant to augment the cytotoxic T lymphocyte (CTL) response of thymocytes to allogenic major histocompatibility complex (MHC) antigen. Supernatants exhibiting the capacity to induce or enhance cell-mediated immune responsiveness were preferentially selected for testing and further purification.
Cells are preferably propagated in Dulbecco's minimal essential medium (DMEM) high glucose formulation (Irvine Scientific, Santa Ana, Calif.), supplemented with L-glutamine and one or more appropriate antibiotics (i.e., penicillin G 100 IU/ml; streptomycin 100 μg/ml). The medium may further be supplemented with 1-10% fetal bovine serum or proven serum-free substitute (e.g. Serxtend™, Irvine Scientific, Santa Ana, Calif.). Maintenance medium is made as noted above, without the serum.
The cell cultures may be propagated and maintained according to known methods. Those used in the present invention were propagated in an artificial capillary bed (hollow fiber bioreactor) according to the method described in Knazek and Gullino, Tissue Culture Methods and Applications , Chapt. 7, p. 321 et seq., Kruse and Patterson, eds., Academic Press, N.Y., 1973, which is incorporated herein by reference. Another means of propagating and maintaining a cell line is via weekly passage and growth in DMEM and 10% fetal calf serum. The growth medium may be removed from 5-day cultures and replaced with serum-free DMEM for 24 hours. The 24-hour supernatant is useful as the source of thymic factor. A cloned feline cell line in accordance with the present invention is permanently maintained by the inventor under the designation Fe2F, a canine cell line is permanently maintained under the designation Ca-9, a bovine cell line is permanently maintained under the designation TF4, and a human cell line is permanently maintained under the designation HU1.
In a preferred embodiment, as illustrated by the following examples, thymic stromal cell-derived TISF is produced by type II epithelial cells. Cloned cells from a primary culture of thymic tissue are selected initially on the basis of morphology (see Beardsley, et al., PNAS 80:6005 (1983)), for example, for a description of desired morphological characteristics). Secondarily, cloned lines are selected on the basis of production of TISF, as determined by known in vivo or in vitro bioassay procedures. Purity of the cultures is maintained via regular monitoring for invasive organisms including viruses, bacteria, and fungi.
Purification of Thymic Factor: TISF is a strongly cationic glycoprotein, and may be purified with cation exchange resin. Purification of the supernatants selected produced a substantially homogeneous factor (TISF). Using known assay techniques as described above, it is now apparent that the effective component of TISF is comprised of at least one polypeptide substantially free of additional endogenous materials. The human, feline, canine and bovine TISF of the present invention are substantially homogeneous 50 kDa glycoproteins with isoelectric points of 6.5.
The amino acid composition of TISF is unlike that of any known cytokine or thymic peptide. The amino acid composition of bovine TISF was determined by conventional methods known to those of skill in the art and is as follows.
Asparagine/Aspartate—8.8%; Threonine—3.5%; Serine—14.7%; Glutamine/Glutamate—13.3%; Proline—2.2%; Glycine—25.7%; Alanine—6.1%; Valine—4.3%; Isoleucine—3.4%; Leucine—6.3%; Tyrosine—2.3%; Phenylalanine—2.6%; Histidine—2.2%; Lysine—4.7%
TISF was purified on a larger scale according to the following protocol. Seed cultures of Fe2F, Ca-9, TF4, or HU 1 were removed from frozen culture and grown in 25 Cm 2 tissue culture dishes in supplemented DMEM. After 14-21 days incubation at 36° C., cultures were used to inoculate a hollow fiber bioreactor. 5×10 6 -10 8 cells were inoculated into the extracapillary space (ECS) of an artificial capillary bed. One liter of DMEM supplemented with L-glutamine and antibiotics (e.g., penicillin G, 100 U/ml or streptomycin, 100 μg/ml) was circulated in the capillary bed.
After seeding the reactor and allowing for adaptation (3-6 weeks), the concentration of fetal bovine serum was gradually decreased to approximately 0.5% in the media. Cultures were fed every other day by replacement of the circulating capillary bed media. Product was harvested from the media removed from the ECS of the reactor. In one procedure, for example, 500-1000 ml media was exchanged in the capillary bed and 30 ml in the ECS.
When one liter of ECS fluid was collected, it was clarified by centrifugation. The clarified material was passed through a sterile chromatography column which contained a strong cation exchange resin (Sepharose S, Pharmacia) with a high affinity for the product at low salt concentrations. The column was eluted with increasing salt concentrations to 0.5M, whereby all extraneous material was removed from the column. The strongly cationic product was then eluted with sterile 2M buffered saline. The material was then diluted with sterile water to the concentration of normal saline. The final product has a preferable concentration of about 1 μg/ml. The product may be lyophilized, if desired, for long term storage.
Example 5
Model cutaneous T-cell lymphoma (CTCL) tumors were established in mice by the method described in T. S. Burger, et al., Establishment of a mouse xenograft model for mycosis fungoides, Experimental Dermatology, 13, 406-412 (2004). Approximately 14 days after implanting tumor cells, the mice were treated with TISF. Tumor volume in mm 3 was evaluated according to Burger, et al., as Size=length×(width) 2 ×0.5. At about the time of the treatment, the tumor growth rate increased sharply in untreated mice, while the single dose of TISF significantly suppressed the tumor growth rate in treated animals. The results are summarized in FIGS. 1 , 4 and 5 . FIG. 1 shows that tumor volume was over twice as large in untreated mice as in treated mice three days after treatment. FIG. 4 shows that a strong effect from a single dose is maintained at least 19 days after a single treatment, and that the effect is much stronger when a purified TISF composition is used. FIG. 5 illustrates that the effect of TISF is dose-dependent.
Example 6
Six-week old NMRI nude mice were obtained from Harlan Winkelmann, Borchen, Germany, and were maintained in individual ventilated cages, food and water ad libitum. CTCL tumor tissue was implanted under anesthesia in the flank of the animals on Nov. 24, 2004, and tumor size was monitored twice weekly using the methods described in Experimental Dermatology, 13, 406-412 (2004). Groups of 10 animals were used for a treatment group and a control group.
The treatment group animals were treated with 100 μL injections of reconstituted TISF solution; the control group animals were injected with 100 μL of dilute saline solution. Treatments were administered daily as follows: Dec. 13-17, 2004; Dec. 20-24, 2004; Dec. 27-31, 2004; and Jan. 3-5, 2005. The animals were sacrificed on Jan. 6, 2005.
When treatments began, the tumor volume was approximately 80 mm 3 . FIG. 2 shows the rate of tumor growth in the control group (represented by square data points) and the treated group (represented by diamond-shaped data points), and demonstrates that the treatment slowed tumor growth substantially. When the animals were sacrificed, tumor volume was nearly three times larger in the untreated (control) animals when compared to the treated animals. FIG. 3 shows the body weights of the animals, and indicates that treatment with TISF had no significant effect on the overall growth rate of the treated animals.
Tissue from the tumors was stained with hematoxylin and eosin for histological examination. Tumor tissue from the treated animals demonstrated a slight increase in coagulative necrosis and a slight increase in angiogenesis relative to the controls. FIG. 4 shows the results of the histological examination of each animal, and FIG. 5 shows representative images of the tumor tissue from treated and untreated animals.
Example 7
Cytotoxicity was measured using a standard MTT assay protocol. MyLa cells were seeded in 96-well plates and TISF, diluted with cell culture medium, was added. Cells were incubated for 16 hours, and cell growth inhibition was measured by standard methods.
TISF Dilution
(reconstituted peptide:medium)
% Inhibition of Cell Growth
4:100
40%
2:100
52%
1:100
54%
0.5:100
52%
0.25:100
35%
0.12:100
44%
0.07:100
17%
0.03:100
11%
The foregoing examples are intended to better explain certain aspects and embodiments of the present invention, and are not intended to define its scope or imply limitations thereon.
|
T4 Immune Stimulating Factor (TISF) selectively induces aberrant T-cells to initiate apoptosis. TISF and peptides that are related to TISF (TISF peptides) are therefore useful for the treatment of disorders characterized by aberrant production, development, or activity of T-cells or other cells of hematopoietic origin. This invention relates to methods of using TISF or a TISF peptide to treat such conditions, compositions containing TISF or a TISF peptide for use in such treatments, and use of TISF or a TISF peptide for the manufacture of pharmaceuticals.
| 0
|
FIELD OF THE INVENTION
This invention is related to Multi-port memory architecture. More particularly, this invention describes the improved architecture for a multi-port memory to enable a reliable differential sensing by creating a common noise while canceling the coupling level.
BACKGROUND OF THE INVENTION
Single port memory allows either a read or write operation for each cycle time. Typically, the single port memory uses either 6 transistor static memory cells (6 T SRAM) or a single 1-transistor dynamic cell ( 1 T). FIG. 1-A shows a transistor level schematic for the typical 6 T SRAM cell 0 . It consists of four NMOS transistors 1 , 2 , 5 , and 6 , and two PMOS transistors 3 and 4 . The PMOSs 3 and 4 and NMOSs 5 and 6 configure a CMOS cross-coupled latch, which maintains a data bit as a storage element. The NMOSs 1 and 2 are used to couple the nodes 7 and 8 to the bitlines (BL and bBL) when a wordline WL is activated. This allows the data bit to be read or written from the BL and bBL. FIG. 1-B shows a transistor level schematic for a dynamic memory cell 10 . It consists of one NMOS transistor 11 and capacitor 12 (1 T DRAM cell). When a WL is activated, the NMOS 11 couples the capacitor 12 to the BL. This allows a data bit stored in the capacitor 12 to be read or written from BL.
Regardless of the 6 T SRAM or 1 T DRAM, only one WL per array can be activated either for a read or write. This is because activating two or more WLs causes a data contention on the common BL. In order to improve the array utilization, a high performance memory system requires a simultaneous read and write operation.
FIG. 2-A shows a transistor level schematic for a dual port static memory cell. It consists of four NMOS transistors 21 , 22 , 25 and 26 , and two PMOS transistors 3 and 4 . Unlike the 1 port SRAM cell, the gates of the NMOS switching transistors, 1 A and 1 B, couple to different wordlines WL 0 and WL 1 . By activating two word lines, WL 0 and WL 1 , a first memory cell coupling to the WL 0 and a second memory cell coupling to the WL 1 can be simultaneously read or written through BL 0 and BL 1 without having a data contention. In accordance with standard usage in the field, the phrase “simultaneously read or written” means ‘during the same clock cycle’. As those skilled in the art are aware, activating WL 0 (or WL 1 ) will turn on all the counterpart transistors 21 (or 22 ) in the row. If the cell to be read and the cell to be written are in the same row, the state of the data will be undefined until the voltages within the cell have stabilized. One of the read and write operations will therefore be delayed according to a convention to avoid contaminating the data. Preferably, the write operation will be done first so that the read operation produces the current data.
FIG. 2B shows a transistor level schematic for a dual port dynamic memory cell. It consists of two NMOS switching transistors 14 A and 14 B, and one capacitor 16 . Similar to the dual port static memory cell, the gates of NMOS switching transistors, 14 A and 14 B couple to the different wordlines WL 0 and WL 1 . By activating two WL 0 and WL 1 , the memory cell coupling to the WL 0 and the memory cell coupling to the WL 1 can be simultaneously read or written through BL 0 and BL 1 without having a data contention.
FIG. 3A shows a transistor level schematic of the 3 T gain cell. The NMOS transistor 34 couples the storage node 32 to the write bitline WBL for a write operation, when the write wordline WWL goes high. The storage node 32 may preferably have a capacitor 35 to store the data bit. The data bit stored in a storage node 32 can be read out to the read bitline RBL when a read wordline RWL goes high. If the storage node 32 contains a high level, two NMOS transistors 31 and 33 are both on, discharging the RBL. If the storage node keeps a low voltage, the NMOS transistor 33 is off, keeping the RBL at the precharged voltage.
FIG. 3-B shows a transistor level schematic for the 2 T gain cell. Similar to the 3 T gain cell, the NMOS transistor 34 couples the storage node 32 to the write bitline WBL for a write operation, when the write wordline WWL goes high. The storage node 32 may preferably have a capacitor 35 to keep the data bit. Unlike the 3 T gain cell, the read NMOS switching transistors 31 are eliminated. The source of the NMOS transistor 32 couples to the read wordline RWL. This thus allows a data bit read operation by measuring a NMOS 33 transistor resistance. A typical method is to apply a voltage between RBL and RWL. They are both high unless they are selected. To read the data bits, RWL goes low. If the data bit is low, the NMOS 33 is off, keeping the RBL at high level. If the data bit is high, the NMOS 33 is on, making the RBL go low. Regardless of the 3 T gain cell or 2 T gain cell discussed above, these cells also allow simultaneous read and write operations.
FIG. 4 shows a memory array architecture for the 3 T gain cell which allows simultaneous read and write operations. A memory 40 consists of an array of 3 T gain cells 42 arranged in a matrix. However, another memory cell, which has a read and write port, may be used. The memory cells are controlled by their corresponding read wordline RWL, write wordline WWL, read bitline RBL, and write bitline WBL. The data bit on the RBL is sensed by the corresponding sense amplifier 43 . The WBL is driven by the write driver circuit 44 . It is assumed that the memory cells 42 A and 42 C are in a write mode by activating WWL 0 , and the memory cells 42 B and 42 D are in a read mode by activating RWL 1 , while disabling WWL 1 and RWL 0 . The memory cell data bits in the cells 42 B and 42 D are read out to the RBL 0 and RBL 1 . They are sensed by the corresponding sense amplifiers 43 . A typical sense amplifier utilizes a reference voltage VREF, which allows discrimination between the voltage on the RBL corresponding to the case of reading either a 1 or a 0 from the memory cell. The memory cell data bits in the memory cells 42 A and 42 C are written through the WBL 0 and WBL 1 . The WBL 0 and WBL 1 are driven by the corresponding write bitline drivers 44 . Note that these read and write operation are simultaneously enabled, which causes a potential RBL and WBL coupling noise.
FIG. 5 shows a simplified RBL and WBL coupling noise model and simulated waveform. It is assumed that the data bit on the RBL 1 is being sensed by utilizing the sense amplifier 43 , while the adjacent WBL 0 and WBL 1 are driven by the write drivers 44 for a write mode. It is also assumed that a read bitline RBL 1 is precharged to VDD through the PMOS 55 . Assuming that the gain cell stores a low data bit, the RBL should maintain VDD. However, when the WBLs go high or low, due to the coupling capacitor between RBL and WBLs, the RBL goes high or low depending on the WBL voltage swing. As shown in a simulation, this coupling noise is as large as 250 mV even if the PMOS load device is not disabled during the sensing operation. Over 250 mV coupling noise makes a simultaneous read and write operation difficult or potentially impossible.
RBL shielding techniques may be used to eliminate this coupling noise. However, this would increase the cell area significantly. Note that this WBL coupling noise to the RBL is a unique problem that results from enabling a simultaneous read and write operation. Note that a conventional BL twisting method is not applicable to cancel the noise, because of a single ended RBL and WBL configuration used in this array.
SUMMARY OF THE INVENTION
The invention relates to an architecture for a memory array of multi-port cells that enables reliable differential sensing by creating common mode noise while simultaneously canceling the coupling level.
A feature of the invention is the use of a pair of twisted bitlines for both the read bitlines and the write bitlines.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B show prior art SRAM and DRAM cells.
FIGS. 2A and 2B show prior art two-port SRAM and DRAM cells.
FIGS. 3A and 3B show alternative prior art DRAM cells.
FIG. 4 shows a prior art array architecture.
FIG. 5 shows a model of noise generation in an array.
FIG. 6 shows an array with interleaved read bitlines for generation of common mode noise.
FIG. 7 shows an array with interleaved write bitlines for cancellation of common mode noise.
FIG. 8 shows an array according to the invention.
FIG. 9 shows a layout of an array.
DETAILED DESCRIPTION
FIG. 6 shows a first method to overcome the problem described in the copending application Ser. No. 10/604,994, filed Aug. 29, 2003 and incorporated by reference in its entirety. A single memory array 60 comprises a plurality of 3 T gain cells arranged in a matrix. However, other memory cells, which have a read and write port, may be used to configure a memory array. The single memory array is further divided into two memory sections 60 A and 60 B. Each WBL is extended into the two memory sections 60 A and 60 B. On the other hand, each RBL 67 in a same column is divided into two local RBL (LRBLA and LRBLB). Each memory column further contains hierarchical read bitlines 66 (HRBLA and HRBLB) that do not connect to the cells. They are arranged over the LRBLA and LRBLB in a different wiring layer. LRBLA and LRBLB (line 67 ) are coupled to the HRBLB and HRBLA (line 66 ) respectively by vertically twisting structure 68 .
The effect of the twisting structure 68 is that the two sections of the bitlines contribute equal and opposite signals to the sense amp; i.e. the two sections have opposite senses of reception in that the same field produces signals of opposite polarity in the two sections of the bitlines. The differential nature of reception of the sense amp input converts the opposite current flows to the same direction so that the received noise from the WBL cancels out on the two sides of the sense amp. The LRBLA and HRBLB in a row 0 are coupled to a differential sense amplifier 63 A. The HRBLA occupies the input to the sense amplifier that would be used by a reference cell in the layout of FIG. 4 .
Similarly, the LRBLA and HRBLB in a row 1 are coupled to a differential sense amplifier 63 B. This interleaved sense amplifier arrangement makes it easy to accommodate sense amplifiers 63 . Optionally, both SA 63 A and 63 B may be arranged only at the A or B side (or without interleaving them). Similar to the sense amplifiers, write driver arrangement 64 A and 64 B is also preferably interleaved. Optionally, both write drivers 64 A and 64 B may be arranged only at the A or B side (or without interleaving them). Each memory section A and B further contains a reference wordline REFWL coupling to reference cells 69 . The reference cell located in this example is within the array not outside of the array. The crossing dot over refwl and LRBLA in FIG. 6 represents the reference cell. The reference cell concept and its timing with regard to RWL is well known to those skilled in the art. The reference cells are connected to a reference voltage (VREF), so that when the reference cell is accessed, the RBL or RBLB which the reference cell is connected to is discharged to a level that is midway between that of the case of a cell storing a high or a low. Each read bitline couples to a PMOS load device 65 , which is always on. Alternatively, a PMOS device may be turned off when a read wordline RWL is selected.
An advantageous feature of this invention is that driving a WBL creates a coupling noise to both LRBLA and LRBLB by the same amount. Coupling between the WBL and the LRBLA and LRBLB is denoted by capacitor 62 A Coupling to the adjacent column is denoted by capacitor 62 B. This is because half of the read line adjacent to WBL is LRBLA and the other half of the read line adjacent to WBL is LRBLB. This generates the common noise, making differential sensing possible.
This first method creates a common noise environment to maintain the differential signal, but the level of the coupling noise is not cancelled. Canceling of common mode level shift is important to avoid a sensing speed dependency on the data pattern. In addition, a WBL couples to all the cells in a column, resulting in a large capacitive write load.
FIG. 7 shows a second method to overcome the problem described in the copending application. A single memory array 70 comprises a plurality of 3 T gain cells arranged in a matrix. However, other memory cells, which have a read and write port, may be used to configure a memory array. The single memory array 70 further is divided into two memory sections 70 A and 70 B. Unlike the first embodiment, each RBL is extended into two memory sections 70 A and 70 B. They are directly coupled to the corresponding sense amplifier 73 together with the other input VREF. On the other hand, each WBL in a column is divided into two local WBL (LWBLA and LWBLB). Each memory section of the column further contains a hierarchical write bitline (HWBLA and HWBLB). The HWBLA and HWLBLB are arranged over the LWBLA and LWBLB in another metal layer. LWBLA and LWBLB are coupled to the HWBLB and HWBLA respectively by vertically twisting them at the twisting area 78 . The LWBLA and HWBLB in a row 0 are coupled to write drivers 74 A and 741 A located at the edge of the memory section A. Similarly, the LWBLA and HWBLB in a row 1 are coupled to the write drivers 74 B and 741 B located at the edge of the memory section B. This interleaved circuit arrangement makes it easy to accommodate the write driver circuitry. Optionally, both all drivers 74 A, 741 A, 74 B and 741 B may be arranged only at either A or B side (or without interleaving them). Similar to the write drivers 74 , sense amplifiers 73 A and 73 B are arranged in an interleaving manner, with one input of the SA connected to (externally supplied) VREF. More particularly, the RBL in a row 0 and the RBL in a row 1 are coupled to the sense amplifiers 73 A located at the A section and 73 B located at the B section, respectively. Optionally, they may be arranged at either A or B side (or without interleaving them). Each read bitline is connected to a PMOS load device 65 , which is always on. Alternatively, a PMOS device may be turned off when a read wordline RWL is selected. An advantageous feature of this invention is that the write drivers 74 and 741 drive the corresponding HWBLA connecting to LWBLB through vertical twist 78 and drive LWLBLA connecting to HWLBLB in the opposite direction (with the opposite polarity). Thus the opposite polarity of the signals received in the adjacent RBL cancels the coupling noise to the adjacent RBL 173 . This is because half of the adjacent RBL 173 is close to LWBLA and the other half of the adjacent RBL 173 is close to LWBLB, where LWBLA and LWBLB swing in the opposite direction. This allows the RBL sensing operation by utilizing a constant RBL reference voltage VREF. The VREF voltage is set to a half level when the RBL discharges when the high data bit would be read out from the memory cell. This second embodiment has the following two disadvantages over the previous embodiment. Firstly, the number of the cells coupling to the RBL is 2× of that for the first method, because one RBL supports all the column. In addition, the differential signal on the RBL pair depends on the speed of the HWBL swing, which may have a skew.
This invention overcomes the disadvantages of the first and second methods for multi-port memory by utilizing a 3 dimensional twisted bitline architecture for both read and write bitline.
A 3 dimensional twisted bitline architecture is shown in FIG. 8 , where each column for both RBL and WBL Pair is divided into 4 segments as shown in FIG. 8 . A section 80 A of the memory array comprises rows 0 and 1 and a section 80 B comprises the remaining rows 2 and 3 . Each row has a Read Word Line RWL and a Write Word Line WWL. Rows 0 and 3 also have a Reference Word Line. REFWL that supplies the reference voltage to the sense amp to determine the data status of the accessed cell by RWL.
On the left of the figure, Column N has corresponding peripheral circuits comprising: a) a sense amp 83 B normally connected to RBLB and RBL and controllably connected by control means shown in FIG. 9 to the reference word line; and b) a pair of write bitline drivers 84 B to drive WBL and WBLB. We need only a single side SA, write bitline driver for column N. The duplication of sense amplifiers and write bitline drivers is an option that provides reduced capacitance between the cells and the sense and drivers.
The sense amplifiers and drivers are activated if the address of the cell to be read from or written to lies in the corresponding half of the array; i.e. if the cell to be read is in section 80 B, the upper sense amp will be activated and the lower sense amp will be disabled. Similarly, for the write bitline drivers. A pair of drivers will be activated if the cell to be written to lies in the adjacent half of the array.
By using two levels of metal, true and complement read bitlines (RBL, RBLB) are formed by vertically twisting the read lines at a point between rows 1 and 2 . The vertical connection may be implemented simply by a pair of vias. Similarly, the write bitlines (WBL and WBLB) are also vertically twisted at points between rows 0 and 1 and between rows 2 and 3 . By twisting the RBLs, voltage coupled from an adjacent active WBL will appear as common mode noise on the RBL. Furthermore by providing complementary twisted write bitlines, rail-to-rail swings on the write bitlines result in minimal common mode voltage disturbance on the RBL.
An array according to the invention thus has an arrangement of read bitlines to suppress the common mode noise and an arrangement of write bitlines to suppress the differential mode noise. As an example, the common mode noise on the read lines has been simulated to be as much as 0.25V in the embodiment of FIG. 6 . The embodiment of FIG. 7 eliminates the noise level coupled to the read bitlines for the same parameters. Creating the common noise and canceling of the common noise level shift is important to avoid a sensing speed dependency on the data pattern. In addition, both RBL and WBL are coupled to half of the cells in the same column, resulting in a fast read and write operation.
FIG. 9 illustrates a layout of an array according to the invention. At the center, areas 92 and 92 A contain WWL drivers and RWL drivers. Illustratively, area 90 A contains columns in the lower half of the figure and area 90 B contains corresponding columns in the upper half.
Areas 93 A, 94 A and 95 A in the lower half of the figure contain peripheral circuits as described above, containing the sense amplifiers, write drivers and RPBUF that are located near the columns that they write to or read from. At the bottom, a set of I/O circuits 96 A interface with off-chip portions of the system that the chip is part of. In this case, there are 512 columns in the block illustrated. The number of columns per block will vary with different designs. A corresponding set of areas 93 B, 94 B, 95 B and 96 B contain corresponding circuits for the upper half.
At the lower left, the write addresses come in from external sources and processed by the logic in write control 91 , which recognize whether the write address is in the upper or lower half of the array and activate circuits accordingly. Similarly, the read addresses enter in the lower right and are processed by read control 91 A. For example, if a read operation is to be performed in the lower half, the correct sense amp in the lower portion will be activated and the sense amp on the upper portion of that column will be disabled, so as to reduce the capacitive load during the read operation.
While the invention has been described in terms of a single preferred embodiment, those skilled in the art will recognize that the invention can be practiced in various versions within the spirit and scope of the following claims.
|
A memory array of dual part cells has a pair of twisted write bitlines and a pair of twisted read bitlines for each column. The twist is made by alternating the vertical position of each bitline pair in each section of a column, with the result of generating common mode nose and of reducing differential mode noise.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority benefit under 35 U.S.C. Section 119(e) to U.S. Provisional Patent Ser. No. 61/304,106 filed on Feb. 12, 2010 the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to methods and systems for hydrocarbon recovery. More particularly, but not by way of limitation, embodiments of the present invention include methods and systems for enhanced hydrocarbon recovery through secondary recovery operations.
BACKGROUND OF THE INVENTION
[0003] Petroleum (crude oil) is a finite resource that naturally occurs as a liquid in formations in the earth. Usually, crude oil is extracted by drilling wells into underground reservoirs. If the pressure of the crude oil underground is sufficient, then that pressure will cause the oil to rise to the surface. When pressure of the crude oil is sufficiently high, recovery simply involves constructing pipelines to carry the crude oil to storage facilities (e.g. tank batteries). This is known as primary recovery. If the pressure of the crude oil in the reservoir is insufficient to cause it to rise to the surface, then secondary means of recovery have to be used to recover the oil. Secondary oil recovery includes: pumping, water injection, natural gas reinjection, air injection, carbon dioxide injection or injection of some other gas into the reservoir.
[0004] The extraction of crude oil from a reservoir by conventional (primary/secondary oil) recovery technology, however, leaves behind a significant portion of the total amount of oil in that reservoir. Traditionally, the oil recovered from a reservoir, using conventional technology as compared to the total amount of oil in the reservoir, is about 33%. Thus, on average, when only conventional methods are used, approximately 67% of the oil in a reservoir is “stranded” in that reservoir. Consequently, an enhanced oil recovery (EOR) processes are used to increase crude oil recovery factors from reservoirs.
[0005] One method of enhanced oil recovery is by utilizing a waterflooding technique. Waterflooding in these reservoirs is characterized by early water breakthrough and rapidly increasing water-oil ratios to an uneconomic level. The injected water tends to travel only through the fractures and not interact with the rock matrix. That is, the water cannot penetrate into the matrix and thereby displace and recover oil trapped in the porous matrix. This injected water tends to recover only the oil left behind in the fracture system following primary production. This limited or no interaction of the water with the matrix is caused in large part by the matrix portion not being water-wet. That is, the matrix will not spontaneously imbibe water.
[0006] One approach to increase the penetration of a water phase with the matrix blocks containing trapped oil is to add a surfactant to the water. A surfactant is a wetting agent that lowers the interfacial tension between fluids or substances. Applied in oil recovery, surfactants reduce the interfacial tension that may prevent oil droplets from moving easily through a reservoir. The use of surfactants in aiding oil to move easily through the reservoir involves the creation of microemulsions. Microemulsions are generally clear, stable, mixtures of oil, water and surfactant, sometimes in combination with a co-surfactant. By themselves, oil and water are immiscible but when oil and water are mixed with the appropriate surfactant, the oil water and surfactant are brought into a single microemulsion phase. The microemulsion's salinity affects the microemulsion's effectiveness in enhancing the recovery of oil from a reservoir. Salinity is a measure of salt content.
[0007] Many EOR techniques have been disclosed in the past yet the EOR process is not widely used by the industry for several reasons. For example, in the EOR processes employing chemicals, petroleum sulfonates and synthetic alkylaryl sulfonates are predominantly used as the surfactant to lower the interfacial tension (IFT) between the residual oil and the injection fluid in order to overcome the capillary forces trapping the oil. Partially hydrolyzed polyacrylamides are generally employed as the viscosifier for mobility control. Both the polymers and surfactants used are not salt and multivalent cation tolerant and therefore either a fresh water source or pre-treatment of the injection water is required. Also, a costly hydration unit is often required for the polymer in order to properly dissolve and develop its viscosity. Furthermore, often a high concentration of the surfactant is required for proper oil displacement, or, alkali is used with the surfactant to enhance the interfacial tension and reduce the surfactant adsorption. In addition, the polyacrylamide may precipitate and cause serious formation damage when contacting the connate water containing multivalent cations. Most polymers are not stable at temperatures above 140° C. and are irreversibly degraded by shear. The huge up-front investment and product limitations currently discourage the wide use of the EOR process.
[0008] The importance of surfactant and polymer adsorption to the practicality and economics of the chemical flooding process has long been recognized because adsorption directly affects the quantity and rate at which surfactant and polymer can be propagated through the reservoir. However, surfactant and polymer floods require precise salinity environment to be effective. Furthermore, lower interfacial tensions induced by surfactant and polymer injection, however, cannot be attained at high sodium chloride concentrations. Additionally, surfactant precipitation and polymer rheological behavior is controlled by the salinity of the brine, which limits the range of salinity under which such processes must be operated.
[0009] Additionally, previous attempt to lower the salinity of the formation by preflushing before EOR processes application has lead to formation damage.
[0010] Therefore, a need exists for a reservoir with appropriate low-salinity characteristics for surfactants and polymer optimum efficiency for enhanced oil recovery.
SUMMARY OF THE INVENTION
[0011] In an embodiment of the present invention, a method to enhance oil recovery from a hydrocarbon-containing formation, the method includes: (a) injecting a mixture of high salinity brine and low salinity brine into the formation, wherein the mixture is injected into the formation through a first pump, wherein the first pump is a automated control pump, wherein the mixture is injected at a flow rate based on the physical characteristics of the formation, wherein the flow rate of the mixture gradually and continuously decreases, wherein the flow rate of the mixture gradually and continuously decreases the concentration within the formation; (b) simultaneously with step(a), injecting fresh water into the formation, wherein the mixture is injected into the formation through a second pump, wherein the second pump is an automated control pump, wherein the fresh water is injected into the formation at a flow rate based on the physical characteristics of the formation, wherein the flow rate gradually and continuously increases; and (c) introducing surfactants and/or polymers into the formation, wherein the surfactant acts as a motive force to drive the hydrocarbons towards one or more production wells.
[0012] In another embodiment of the present invention, a method to enhance oil recovery from a hydrocarbon-containing formation, the method includes: (a) injecting a mixture of high salinity brine and low salinity brine into the formation; (b) simultaneously with step(a), injecting fresh water into the formation; and (c) introducing surfactant and/or polymers into the formation, wherein the surfactant acts as a motive force to drive the hydrocarbons towards one or more production wells.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention, together with further advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
[0014] FIG. 1 shows permeability and conductivity profiles during high salinity and fresh water salinity displacement during laboratory experimentation utilizing sandstone sample A.
[0015] FIG. 2 shows permeability and conductivity profiles during high salinity and fresh water salinity displacement during laboratory experimentation utilizing sandstone sample B.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not as a limitation of the invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations that come within the scope of the appended claims and their equivalents.
[0017] A fundamental requirement for a successful chemical flood is to provide an adequate ionic environment for surfactant and polymer, to ensure that the desired interfacial activity, phase behavior, and mobility control are maintained. Establishing an appropriate reservoir salinity level to reduce the surfactant and polymer adsorption consequently reduce the optimal costs and results in additional retrieval of downhole hydrocarbons.
[0018] Surfactant and polymer displacement efficiency depends essentially on lowering the interfacial tension and maintaining reservoir permeability and injectability. An understanding of the relationship between low tensions and phase behavior shows the displacement mechanisms necessity of controlling, if not maintaining, the conditions of optimum flow and phase behavior. Thus, the use of water salinity gradient for gradual and continuous dilution of high salinity brine in the system is better suited for surfactant and polymer flooding conditions than the preflush technique or any method used to prevent precipitation, salting out, adsorption or phase inversion.
[0019] In an embodiment, a mixture of low salinity brine and high salinity brine are pumped into the hydrocarbon-containing formation to gradually and continuously reduce the salinity within the formation. In an embodiment, the pump is an automated control pump. The mixture is injected into the formation at a flow rate dependent on the physical characteristics of the formation. In an embodiment, the mixture is injected into the formation at a ramp rate of Q to 0.
[0020] Simultaneously with injecting the high and low salinity mixture into the formation, a second pump injects fresh water into the formation. In an embodiment, the pump is an automated control pump. The fresh water is injected into the formation at a rate dependent on the physical characteristics of the formation. In an embodiment, the fresh water is injected into the formation at a ramp rate from 0 to Q.
[0021] In an embodiment, the first pump and the second pump are pumping inside an inline mixer. The total flow rate exiting the mixer is Q. The salinity is thus gradually and continuously reduced.
[0022] In an embodiment, a mixture of low salinity brine and high salinity brine are pumped into the hydrocarbon-containing formation to gradually and continuously reduce the salinity within the formation to prevent formation damage.
[0023] In an embodiment, a mixture of low salinity brine and high salinity brine are pumped into the hydrocarbon-containing formation to gradually and continuously reduce the salinity within the formation to established a favorable environment for chemical flooding
Example
[0024] From simulation results, it was discovered that an optimum salinity profile embodying principles of the present invention provided a higher oil recovery.
[0025] A sandstone core sample, 1.5 inch in diameter and 3 inches in length, which was vacuum saturated with high salinity brine (35,000 ppm) was placed in a coreholder. Next, a 500 psi overburden pressure is applied to the core sample.
[0026] The coreholder, containing the core sample, is then connected to an automatic controlled pump, which delivers a mixture of high salinity brine and low salinity brine at a chosen flow rate Q calculated based on the physical characteristics of the sample. Pressures upstream and downstream of the sample were recorded using high pressure transducers for permeability determination. The permeability was computed using Darcy's law for one dimensional flow of a homogeneous fluid through porous media.
[0027] After the pressure drop across the core stabilized and the high salinity brine permeability was established, a second pump was connected to deliver fresh water. The first pump and the second pump were connected to an inline mixer. The two pumps were set in a way so that the high salinity brine delivery rate ramped down from Q to 0, while the fresh water delivery rate ramped up from 0 to Q. The total flow rate exiting the mixer was constant at Q during the entire experiment. This step gradually and continuously decreased the water salinity from 35,000 ppm to 0 ppm. The upstream and downstream pressure helped quantify the damage, if any.
[0028] FIGS. 1 and 2 provide examples of permeability and conductivity profiles during high salinity and fresh water displacement under experimental conditions utilizing two different core samples.
[0029] The process was then switched back to the high salinity brine to verify that the permeability of the sample had not been compromised. After the pressure drop across the core stabilized and the high salinity brine permeability was reestablished, the flow rate was abruptly (i.e., shocked) changed from the salt water solution to fresh water. This step confirmed that the sample used was sensitive to water chemistry and the injection scheme. The presence of clay particles in the effluent stream from the shocked cores was detected by the turbinity measurements.
[0030] The preferred embodiment of the present invention has been disclosed and illustrated. However, the invention is intended to be as broad as defined in the claims below. Those skilled in the art may be able to study the preferred embodiments and identify other ways to practice the invention that are not exactly as described in the present invention. It is the intent of the inventors that variations and equivalents of the invention are within the scope of the claims below and the description, abstract and drawings not to be used to limit the scope of the invention.
REFERENCES
[0031] All of the references cited herein are expressly incorporated by reference. The discussion of any reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication data after the priority date of this application. Incorporated references are listed again here for convenience:
1. Kia, S. F.; Fogler, H. S; Reed, M. G., “Effect of salt composition on clay release in Berea Sandstones”, Soc. of Petrol. Engrs., 1987, SPE Int'l. Symposium on Oilfield Chemistry, San Antonia, Tex. 2. Sharma, M. M., Yortsos, Y. C., “Permeability impairment due to fines migration in Sandstones”, Soc. of Petrol. Engrs., 1986, SPE Formation Damage Control Symposium, Lafayette, La. 3. Lake, L. W.; Helfferich, F., “Cation exchange in chemical flooding: Part 2—The effect of dispersion, cation exchange, and polymer/surfactant adsorption on chemical flooding environment”, Soc. of Petrol. Engrs., 1978, pp. 16, (6), 435-444. 4. Hiraski, G., “Ion exchange with clays in the presence of surfactant”, Soc. of Petrol. Engrs., 1982, pp. 22, (2), 181-192, SPE Formation Evaluation. 5. Campbell, T. C., “Chemical flooding: A comparison between alkaline and soft saline preflush system for removal of hardness ions from reservoir brines”, Soc. of Petrol. Engrs., 1978, SPE Oilfield in Geothermal Chemistry Symposium, Houston, Tex. 6. Delshad, M.; Han, W.; Pope, G. A.; Sepehrnoori, K.; Wu, W.; Yang, R.; Zhao, L., “Alkaline/Surfactant/Polymer Flood Prediction for the Karamay Oil Field”, Soc. of Petrol. Engrs., 1998, SPE/DOW Improved Oil Recovery Symposium, Tulsa, Okla. 7. Griffith, T. D., “Application of the ion exchange process to reservoir preflushes”, SPE Annual Fall Technical Conference and Exhibition, American Institute of Minin, Metalllurgical, and Petroleum Engineer, Inc., Houston, Tex., 1978. 8. Healy, R. N.; Reed, R. L., “Immiscible Microemulsion Flooding”, 1977, pp. 17, (2), 129-139. 9. Hill, H. J., “Cation Exchange in Chemical Flooding: Part 3—Experimental”, 1978, 18, (6), 445-456. 10. Hill, H. J.; Helfferich, F. G.; Lake, L. W.; Reisberg, J.; Pope, G. A., “Cation Exchange and Chemical Flooding”, SPE Journal of Petroleum Technology, 1977, pp. 29, (10), 1336-1338. 11. Hirasaki, G., “Ion Exchange with Clay in the Presence of Surfactant”, 1982, pp. 22, (2), 181-192. 12. Lake, L. W.; Helfferich, F., “Cation Exchange Chemical Flooding: Part 2—The Effect of Dispersion, Cation Exchange, and Polymer/Surfactant Adsorption on Chemical Flooding Environment”, 1978, pp. 18, (6), 435-444. 13. Okasha, T. M.; Alshiwaish, A., “Effect of brine salinity on interfacial tension in Arab-D Carbonate Reservoir, Saudi Arabia”, Soc. of Petrol. Engrs., 2009, SPE Middle East Oil and Gas Show and Conference, Bahrain, Bahrain. 14. Pope, G. A.; Lake, L. W.; Helfferich, F. G., “Cation Exchange in Chemical Flooding: Part 1—Basic Theory Without Dispersion”, 1978, pp. 18, (6), 418-434. 15. Sharma, M. M.; Yortsos, Y. C., “Permeability impairment due to fines migration in Sandstones”, Soc. of Petrol. Engrs., 1986, SPE Formation Damage Control Symposium, Lafayette, La. 16. Tang, G. Q.; Morrow, N. R., “Influence of brine composition and fines migration on crude oil/brine/rock interactions and oil recovery”, Journal of Petroleum Science and Engineering, 1999, pp. 24, (2-4), 99-111. 17. Valdya, R. N.; Folger, H. S., “Fines migration and formation damage: Influence of pH and ion exchange”, SPE Production Engineering, 1992, pp. 7, (4), 325-330.
|
The present invention relates generally to methods and systems for hydrocarbon recovery. More particularly, but not by way of limitation, embodiments of the present invention include methods and systems for enhanced hydrocarbon recovery through secondary recovery operations.
| 4
|
This is a continuation of application Ser. No. 08/242,105, filed May 13, 1994, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the coding of video signals and in particular the coding of video signals for storage and subsequent transmission.
2. Related Art
Broadcast quality television signals require around 6 MHz of analogue bandwidth or in excess of 100 Mbit/s of information for a digital format obtained by sequentially sampling an analogue signal to produce a PCM digital signal.
Such high bit rate signals are expensive to transmit and for transmission cost reasons therefore it is desirable to reduce the amount of information required. This can be done by taking advantage of the correlation between neighbouring elements of a picture (pixels) and thus compromising between the reduction in information and the quality of the picture.
Redundancy reduction techniques assume there is some correlation between neighbouring pixels, either in space and/or in time. For instance, in an area of a scene which is relatively uniform (for instance a wall of a room), the pixel values of neighbouring pixels within this area are likely to be fairly close. Similarly, in a fairly static scene, the pixels of one frame will correspond closely to the equivalent pixels of a previous frame.
Hence pixels of a single frame can be coded with respect to their relationship to each other (intraframe coding) and/or with respect to their relationship with pixels of neighbouring frames (interframe coding). Intraframe coded frames (intrapictures) can clearly be decoded without reference to any other frame whilst interframe coded frames (interframes) require information relating to the frames used in the prediction. Differential coding techniques may also be used to compress video signals further. Since interframe differential coding may result in the irretrievable loss of some information owing to transmission errors, artifacts will occur in a decoded picture if only interframe differential coding is used. It is thus usual for a combination of intra- and inter-frame coding techniques to be used, the intraframes restoring the integrity of the decoded signal.
Other compression techniques can also be employed; for instance transform coding which seeks to exploit the correlation of pixel magnitudes within a frame by finding another set of coefficients, the magnitude of many of which will be relatively small. These coefficients can then be quantised coarsely or omitted altogether. The transform coefficients of a frame can thus be coded using less information. One popular form of transform coding uses the discrete cosine transform (DCT).
Another form of interframe compression technique is motion compensation coding which involves the identification of areas in successive frames which appear to correspond but have moved within the frame. A motion vector is calculated for each such area and a predicted frame is then formed from the previous frame and the motion vectors. Errors between the predicted frame and the actual frame are then calculated and, together with the motion vectors, coded. This may result in less information than that of two frames taken together.
The compression of video signals is the subject of much standardisation work. One such standard is the ISO-IEC 11172 standard "Coding of moving pictures and audio for digital storage media at up to about 1.5 Mbit/s", known as MPEG-1, which relates to the storage of video and associated audio on digital storage media such as CD-ROM, digital audio tape (DAT), tape drives, writable optical drives or for transmission over telecommunication channels such as an integrated services digital network (ISDN) and local area networks. Such coding techniques are attractive for the provision of audiovisual services over limited bandwidth systems.
The time taken to access and retrieve a stored video signal can be prohibitive to the provision of interactive video services in which a consumer selects a particular service from a range of available services. The access time is increased dramatically if the stored video signal requires further processing before it can be output to a display device.
A recent development in such services is the provision of home entertainment or shopping services in which a consumer selects a service from a range on offer and the relevant video signal is transmitted to the consumer's premises from a central server. In a video-on-demand environment, for example, a consumer uses a central video server in the manner of a remote video cassette player. Consumers therefore expect the same facilities as they would have on their own video cassette player e.g. the facility to play, pause, stop, fast forward and reverse.
Various processors are available which provide these facilities. When a consumer requests play, the coded video signal stored at the remote server is transmitted to the consumer. A local decoder at the consumer's premises decodes the incoming signal to produce a video image on a television set. In the pause mode, a pause signal is sent to the server which, in response, sends a signal to the consumer's decoder indicating that the frame is unchanged.
When fast forward or reverse is selected however, the coded signal must be processed further by the video server. When a consumer requests fast forward, a signal is sent to the server which then transmits every, say, fourth frame of the coded signal. If the video signal is in an uncompressed format, the server has to locate the beginning of every fourth frame in the video signal and transmit these to the consumer. This is very processor and time intensive and may result in a delay that would be unacceptable to consumers.
Similarly, if compression coding techniques have been employed, the fifth frame of the picture may have been coded with reference to the fourth frame. If in the fast forward mode only the first, fifth, ninth etc. frames are to be sent, each frame to be sent must be recoded with respect to the preceding frame to be sent. This is very processor- and time-intensive. For video signals coded using only intraframe coding, it is known to provide a fast forward mode by extracting the intraframe coded frames (intrapictures) from the encoded video signal and transmitting these frames in their original order. Similarly they could be sent in the reverse order for the fast reverse mode. However, not only does the server, on receiving a fast forward request signal, have to search the coded signal for intrapictures but the bit rate of the resulting signal will be increased as compared to the play mode since the intrapictures include very little compression. The decoder at the consumer's premises therefore has to be able to manage excessive changes in the bit rate.
SUMMARY OF THE INVENTION
In accordance with the invention a method of coding a moving picture comprises generating a first sequence of digital signals representing a set of images of the moving picture and at least one further sequence of digital signals representing a further set of images of the moving picture.
It will be appreciated that the generated sequences of digital signals will have an increased storage requirement compared to a sequence which represents a play mode. However, the coded sequences of data can be played back without any further processing of the data. In addition, since the sequences are coded using the same coding means, the average bit rate of the sequences will be the same. A decoder for decoding the sequences can therefore be simplified as compared to known decoders since the decoder does not need to include means for managing excessive changes in bit rate.
The sequences may be generated using any suitable coding techniques such as PCM or compression coding. A combination of intraframe, interframe, differential, DCT and motion compensation techniques may be used. Preferably a technique that conforms to IS 11172 or CCITT Recommendation H.261 is employed.
The sequences preferably represent a play mode and any combination of a reverse play mode, a fast forward mode or a fast reverse mode, the further set of images in the latter two cases being a subset of the first set of images. Any suitable number of playback modes may be provided; for example two fast forward modes may be coded, one at three times the speed of the normal play mode and another at six times the speed of the play mode.
The sequences may be generated by interframe differential coding. Preferably, the first sequence is generated by comparing, at each input of a new frame of the moving picture, a current frame of the moving picture with a frame immediately preceding the current frame and a further sequence is generated by comparing, at the input of every nth frame of the moving picture, the current frame with the preceding such frame, where n is an integer greater than 1.
The invention also provides a data carrier having recorded thereon a first sequence of digital signals representing a set of images of a moving picture and at least one further sequence of digital signals representing a further set of images of the moving picture.
Preferably the or each further set of images is a subset of the first set. The subset may represent a fast forward playback mode and/or a fast reverse playback mode.
The data carrier may take any suitable form, for instance CD-ROM, DAT, tape drives or writable optical drives. For a typical fast forward or fast reverse sequence to run at 6 times the play speed, an extra storage capacity of 16% would be required compared to the storage capacity required for a sequence corresponding to the play mode only.
There is also provided according to the invention a video replay apparatus comprising switching means for switching between a first sequential file and a second sequential file of a record medium, a position counter for recording the current position on a sequential file being played and means, responsive to the position counter and to information stored on the record medium, to determine a corresponding position on the other sequential file.
Preferably the determining means, responsive to information stored on the record medium relating to the lengths of the sequential files, calculates the proportion of the length of the file being played that is represented by the current position in said file and calculates the position in the said other file that corresponds to the same proportion of the length of the other file. Thus if the file being played represents a play mode of a moving picture and the current position is 25% through the sequential file, the corresponding position in a second sequential file representing a fast forward mode, is 25% through the second file.
Similarly, if the first file represents a play mode of a moving picture and the second file represents a reverse mode, the corresponding position in the reverse mode can be determined by calculating the remaining proportion of the length of the file being played and calculating the position in the said other file that corresponds to the remaining proportion of the file being played. Hence if the player is 75% of the way through the first file, the corresponding position is 25% of the way through the second file.
The video replay apparatus may be used in an interactive video system in which the record medium is accessed in response to a signal from a remote consumer and a relevant sequence is output for reception by a decoder at the consumer's premises.
According to a further aspect of the invention a video coder comprises a preprocessor for selecting frames of a video signal, coding means for generating a first sequence of digital signals representing a set of images of a moving picture and at least one further sequence of digital signals representing a further set of images of the moving picture, and means for writing the sequences onto a data carrier.
The or each further set of images may be a subset of the first set, so representing fast forward or fast reverse playback modes of the moving picture. The coder is preferably operable to encode every frame of a moving picture and also operable to encode every nth frame of the moving picture, where n is an integer greater than 1.
Preferably the coding means includes interframe differential coding means.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described further by way of example only with reference to the accompanying drawings in which:
FIG. 1 shows a coder according to the invention;
FIG. 2 is a schematic diagram indicating coded sequences produced by the coder of FIG. 1; and
FIG. 3 shows an interactive video system according to the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
FIG. 1 shows a coder 2 for coding a digital video signal according to the MPEG-1 standard. This standard relates to the coding of video at bit rates around 1.5 Mbit/s. The MPEG-1 standard features intrapictures and predicted pictures, which may be coded with reference to a preceding intrapicture or a preceding predicted picture. The MPEG-1 standard also features interpolated pictures which are coded with reference to a past and a future intrapicture or predicted picture.
The coder of FIG. 1 is intended to generate coded sequences representing three playback modes of the input video signal: play, fast forward and fast reverse. To generate a fast forward or reverse sequence at n times normal play speed, every nth frame of the input video is coded. Hence a fast forward speed that is 3 times normal play speed corresponds to every third input frame after the first being coded and, similarly, the reverse speed corresponds to every third input frame, in the reverse order, being coded.
A digital video signal representing a moving picture is input to a preprocessor 3 which selects the frames of the video signal which are to be coded. When the play sequence is to be generated, the preprocessor does not need to reorganise the input signal and thus the frames are passed directly to a current frame store 4. When a sequence other than the play sequence is to be generated, the preprocessor must select the frames to be coded. For instance, to generate a sequence representing a fast forward playback mode at three times the normal play mode, the preprocessor 3 outputs the first and every third frame thereafter to the current frame store 4. Similarly, when a reverse mode is to be coded, the preprocessor selects the relevant frames from the input video signal, when it is played in reverse.
The frames selected by the preprocessor 3 are input, frame by frame, to the current frame store 4 which stores a single input frame of the video signal. The first input frame of the video signal is coded as an intrapicture and thus is the only input to a subtracter S. The output of the subtracter S is input to a DCT transformer 6 which transforms the input data into DCT coefficients which are then quantised by a quantiser 8. The data then passes to a variable length coder (VLC) 10 which codes the data from the quantiser. The resulting coded data for the first frame is then stored on a record medium 12. Data from the quantiser 8 also passes to an inverse quantiser 18 and an inverse DCT 20 to reproduce the current frame of the input signal. This frame is stored in a previous frame store 22. A second frame store 24 stores subsequent frames which, together with the frame stored in the previous frame store 22, can be used to code a frame using bidirectional coding techniques, as is required in the MPEG-1 standard. Following frames of the input signal are coded using forward prediction, bidirectional prediction or intraframe techniques.
To generate a play sequence, every input frame is coded. For this purpose, as described above, the output of the inverse DCT 20 is stored in the previous frame store 22. On the input of a second frame to the current frame store 4, the contents of the previous frame store 22 and the current frame store 4 are input to a motion estimator 26 which calculates the motion vectors for the current frame. The motion vectors are input to a motion compensation predictor 28 together with the contents of the previous frame store 22 to produce a prediction of the current frame. This predicted frame is subtracted from the actual current frame of the input signal by the subtracter S and the resulting difference signal processed by the DCT 6 and the quantiser 8. The signal is then coded, as described above, by the VLC 10 which also multiplexes the coded difference signal with the motion vectors, quantisation parameters and inter/intra classification necessary for subsequent decoding. This coded data is then stored on the record medium 12.
The processing of the input video signal continues on a frame by frame basis until the whole video signal is coded. The record medium 12 will then contain a sequence of coded data representing the play mode of the video signal.
To generate a fast forward sequence at three times the normal play speed, every third input frame after the first frame is coded. When the fourth frame of the video signal is input to the current frame store 4 from the preprocessor 3, the predicted frame calculated from the contents of the previous frame store 22 (i.e the first frame) are subtracted by subtracter S from the actual fourth frame stored in current frame store 4. The difference signal produced is then processed by the DCT 6, the qualitiser 8 and the VLC 10 and stored on the record medium 12. This coding process continues for every third frame as schematically illustrated in FIG. 2.
Similarly, to generate a fast reverse sequence, every third frame of the reversed video signal is coded. This coded sequence is also stored on the record medium 12.
Hence three sequences of coded data are generated independently of each other: one representing the play mode, one representing the fast forward mode and one representing the fast reverse mode. All the sequences have the same constant average bit rate since they are encoded using the same technique.
FIG. 3 shows a system for supplying video-on-demand. A server 30, for instance a mainframe computer, is connected to a number of remote decoders 32 located at consumers'premises via telecommunication links 34. The server 30 receives signals from the consumers and accesses a record medium 12 which stores coded sequences of data. On receipt of a signal from a consumer, the server accesses the relevant coded sequence and transmits the sequence to the consumer's decoder 32 via the link 34. The decoder 32 at the consumer's premises decodes the coded sequence and displays the resulting video signal on a television set.
If a consumer requests a playback mode, the server 30 is able to move from one sequence to the other without an unacceptable positioning error within the sequence owing to the constant average bit rate of the coded sequences. Interpolation from one sequence to another can be achieved using a pointer to the position within the sequence and the lengths of the particular sequence. That is to say:
pos.sub.fast forward =pos .sub.play ×length.sub.fast forward /length.sub.play
where:
pos=position within the sequence, in any suitable dimension e.g. time, bits etc.
length=length of sequence, in the same units as pos
Thus, if a consumer has viewed 75% of a film and requests fast forward, the server calculates the corresponding position in the fast forward sequence as follows:
pos.sub.fast forward =75×length.sub.fast forward /100
i.e. the server accesses the fast forward sequence three quarters of the way through the sequence. When the consumer requests play mode, the server calculates the position reached within the fast forward sequence and calculates the corresponding position within the play sequence, as described above.
Similarly, the corresponding position within a fast reverse sequence can be calculated from the current position within the play sequence as follows:
pos.sub.reverse =(length.sub.play -pos.sub.play)×length.sub.reverse /length.sub.play
Whilst the above embodiment of the invention has been described with reference to a video-on-demand system, it should be appreciated that the invention may be employed in any other suitable interactive video system, for instance home shopping or entertainment services.
|
A method of coding a moving picture comprising generating a first sequence of digital signals representing a set of images of a moving picture and at least one further sequence of digital signals representing a further set of images of the moving picture and writing the sequences onto a data carrier. The or each further set of images may be a subset of the first set. An interactive video system can access and transmit a sequence as requested by a consumer without further processing of the digital signals.
| 7
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to bearings, and more particularly to a sliding ceramic bearing which can be readily produced.
[0003] 2. Prior Art
[0004] Sliding bearings and rolling bearings are popularly used in applications such as attaching a rotary axle to a machine frame, etc.
[0005] Common types of rolling bearings include ball bearings, roller bearings and needle bearings, in which rolling members such as balls, rollers, and needles are provided between an inner ring and an outer ring. The friction between the inner ring and the outer ring is known as “rolling friction,” and is generally very small. Therefore, rolling bearings provide good high-speed operating capabilities. However, the roller members between the inner ring and the outer ring are prone to crack or deform under a heavy load. When this happens, the operating precision is dramatically decreased. In addition, the manufacturing costs of roller bearings are very high, especially roller bearings used in small devices such as computer fans.
[0006] Therefore, in small devices, sliding bearings are often used because of their relatively low manufacturing costs. A typical sliding bearing comprises an annular bearing sleeve having a circular bore, and a cylindrical shaft rotating in the bore. Most bearing sleeves used today are made of a copper-based alloy or stainless steel. The friction between the bearing sleeve and the shaft is known as “sliding friction,” and is generally very large. To reduce the friction between the shaft and the bearing sleeve, a diameter of the bore of the bearing sleeve is configured slightly larger than a diameter of the shaft in order to provide an operating clearance, and an oil film is established in the operating clearance to act as a lubricant. Because of the operating clearance, the shaft is usually not located exactly along a central axis of the bearing sleeve. Instead, the shaft is displaced slightly from the central axis so that it rotates about an axis that is eccentric to the central axis. This leads to unsteady rotation of components mounted on the bearing sleeve. However, if the operating clearance is configured to have a reduced size, the lubricant therein may be forced out. When this happens, the bearing sleeve directly contacts the shaft, and the sliding bearing rapidly wears out. Therefore, sliding bearings usually have short lifetimes.
[0007] With the development of technology in fields where slide bearings are applied, modem slide bearings are being required to rotate at unprecedented high speeds. The problem of “sliding friction” is becoming commensurately more important. Traditional low abrasion, high hardness materials used for slide bearings are increasingly unable to provide satisfactory high-speed, long-life performance under harsh operating conditions. New materials for bearings are being eagerly sought. It has been found that certain ceramics have high compression strength, high friction resistance, and a small coefficient of friction. Ceramics are now widely considered to be a more serviceable material for slide bearings than traditional materials. Studies have shown that in ceramic slide bearings, it is feasible to reduce the contact area between the bearing sleeve and the shaft in order to reduce the friction therebetween, without diminishing the operating reliability of the slide bearing.
[0008] Taiwan Patent Publication No. 495118 discloses a sliding bearing made of ceramic material. In order to reduce the contact area between the bearing sleeve and the shaft, either an outer surface of the shaft or an inner surface of the bearing sleeve is configured to be non-cylindrical. When the bearing sleeve receives the shaft therein, at least a portion of the outer surface of the shaft does not contact the inner surface of the bearing sleeve, so that the contact area is reduced. However, the advantages of high compression strengthen and high abrasive resistance of the ceramic material also present novel problems in manufacturing the bearing sleeve, as detailed below.
[0009] Referring to FIG. 1, to attain a high degree of surface smoothness, a bore 4 of a bearing sleeve 1 needs to be ground with a grinding machine 2 . The grinding machine 2 has a grinding bit 3 rotatingly machining the surface of the bearing sleeve 1 that defines the bore 4 . During this process, the grinding bit 3 is subjected to a diametrical force by the bearing sleeve 1 . This causes the grinding bit 3 to bend, especially when the grinding bit 3 is extended far into the bore 4 . As a result, the ground bore 4 is irregular. That is, a diameter of the bore 4 nearest the grinding machine 2 is larger than a diameter of the bore 4 farthest from the grinding machine 2 . One means of ameliorating this problem is to perform double-ended grinding. Referring to FIG. 2, two grinding machines 2 are provided to simultaneously grind the bore 4 at opposite ends thereof. Each grinding bit 3 has to penetrate only halfway into the bore 4 . Accordingly, the grinding bits 3 are subjected to reduced diametrical forces, and the ground bore 4 is more uniform. However, it is generally not possible to completely eliminate irregularity of the bore 4 . In addition, the two ground halves of the bore 4 may not be precisely coaxial, due to inherent manufacturing error.
SUMMARY OF THE INVENTION
[0010] Accordingly, an object of the present invention is to provide a ceramic bearing which can be easily produced.
[0011] To achieve the above-mentioned object, a ceramic bearing assembly in accordance with a preferred embodiment of the present invention comprises a shaft adapted for being mounted to a complementary supporting structure, and a bearing sleeve rotatably receiving the shaft. The bearing sleeve comprises an inside wall surrounding the shaft, and an outer surface adapted for being mounted to a rotatable body. A series of first bearing blocks is formed at the inside wall at a first end of the bearing sleeve, and a series of second bearing blocks is formed at the inside wall at a second end of the bearing sleeve. The first bearing blocks are arranged in circular fashion, and the second bearing blocks are arranged in circular fashion complementarily offset from the first bearing blocks. Each of the first and second bearing blocks defines a concave bearing surface, the bearing surfaces cooperatively supporting the shaft therebetween.
[0012] Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of the preferred embodiment of the present invention with attached drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 is an exploded, isometric view of a ceramic bearing assembly in accordance with the preferred embodiment of the present invention, the ceramic bearing assembly comprising a bearing sleeve and a cylindrical shaft;
[0014] [0014]FIG. 2 is a schematic, cross-sectional view of the bearing sleeve of the ceramic bearing assembly of FIG. 1, corresponding to line II-II thereof;
[0015] [0015]FIG. 3 is a schematic, cross-sectional view of the bearing sleeve of the ceramic bearing assembly of FIG. 1, corresponding to line III-III thereof;
[0016] [0016]FIG. 4 is a schematic, cross-sectional view of the bearing sleeve of the ceramic bearing assembly of FIG. 1, corresponding to line IV-IV thereof;
[0017] [0017]FIG. 5 is a left end elevation of the bearing sleeve of the ceramic bearing assembly of FIG. 1;
[0018] [0018]FIG. 6 is a schematic side elevation of two grinding machines grinding an inside wall of the bearing sleeve of the ceramic bearing assembly of FIG. 1; and
[0019] [0019]FIGS. 7 and 8 are schematic side elevations of respective grinding machines grinding an inside wall of a conventional bearing sleeve.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] Referring to FIG. 1, a ceramic bearing assembly in accordance with the preferred embodiment of the present invention comprises a bearing sleeve 10 made of ceramic material, and a cylindrical shaft 20 fitted in the bearing sleeve 10 . The shaft 20 is adapted to be mounted to a complementary supporting structure.
[0021] The bearing sleeve 10 has a cylindrical outer surface. The outer surface is adapted for being mounted in a bore of a rotatable body (not shown). A series of evenly spaced first grooves 12 and a series of evenly spaced second grooves 14 are defined in an inside wall of the bearing sleeve 10 . The first and second grooves 12 , 14 are each generally parallel to and equidistant from an axis of rotation 18 of the bearing sleeve 10 . The first grooves 12 span from a first end of the bearing sleeve 10 toward a second end of the bearing sleeve 10 . The first grooves 12 are slightly tapered, such that they are narrowest at inmost ends thereof and widest at the first end of the bearing sleeve 10 . The second grooves 14 span from the second end of the bearing sleeve 10 toward the first end of the bearing sleeve 10 . The second grooves 14 are slightly tapered, such that they are narrowest at inmost ends thereof and widest at the second end of the bearing sleeve 10 . The first and second grooves 12 , 14 are disposed adjacent each other in alternate fashion in a center portion of the bearing sleeve 10 between the first and second ends.
[0022] Referring also to FIG. 5, a series of evenly spaced first bearing blocks 120 is formed at the inside wall of the bearing sleeve 10 at the first end of the bearing sleeve 10 . The first bearing blocks 120 extend from the first end of the bearing sleeve 10 to inmost ends of the second grooves 14 respectively. Thus the first bearing blocks 120 and the first grooves 12 are arranged at the first end of the bearing sleeve 10 in alternate fashion. Each first bearing block 120 is slightly tapered, such that it is widest at an inmost end thereof and narrowest at the first end of the bearing sleeve 10 . Each first bearing block 120 defines a concave first bearing surface 122 thereon. A radius of curvature of the first bearing surface 122 corresponds to the axis 18 of the bearing sleeve 10 . Said radius of curvature is substantially the same as a radius of the shaft 20 . A series of evenly spaced second bearing blocks 140 is formed at the inside wall of the bearing sleeve 10 at the second end of the bearing sleeve 10 . The second bearing blocks 140 extend from the second end of the bearing sleeve 10 to inmost ends of the first grooves 12 respectively. Thus the second bearing blocks 140 and the second grooves 14 are arranged at the second end of the bearing sleeve 10 in alternate fashion. Each second bearing block 140 is slightly tapered, such that it is widest at an inmost end thereof and narrowest at the second end of the bearing sleeve 10 . Each second bearing block 140 defines a concave second bearing surface 142 thereon. A radius of curvature of the second bearing surface 142 corresponds to the axis 18 of the bearing sleeve 10 , and is the same as the radius of curvature of the first bearing surface 122 .
[0023] Referring to FIG. 4, each first groove 12 has an open end at the first end of the bearing sleeve 10 , and an opposite dead end at the corresponding second bearing block 140 . Similarly, each second groove 14 has an open end at the second end of the bearing sleeve 10 , and an opposite dead end at the corresponding first bearing block 120 . It is noted that FIG. 4 shows only one first groove 12 and its corresponding second bearing block 140 , and only one second groove 14 and its corresponding first bearing block 120 . This construction of the bearing sleeve 10 is advantageously accomplished by injection molding, as described in detail below. However, it should be noted that the configuration of the bearing sleeve 10 may have other alternative forms, and that construction of the bearing sleeve 10 may be accomplished by means other than injection molding.
[0024] In the preferred embodiment of the present invention, there are three first grooves 12 , three second grooves 14 , three first bearing blocks 120 and three second bearing blocks 140 . In alternative embodiments, other numbers of these components may be adopted according to need.
[0025] In assembly, the shaft 20 is received in the bearing sleeve 10 . Referring to FIGS. 2 and 3, a profile of the shaft 20 is shown in dashed lines. A first end of the shaft 20 is surrounded and supported by the first bearing surfaces 122 of the first bearing blocks 120 , and an opposite second end of the shaft 20 is surrounded and supported by the second bearing surfaces 142 of the second bearing blocks 140 .
[0026] Generally, the bearing sleeve 10 is produced by three steps. First, a ceramic greenbody is formed, by injection molding a composite comprising ceramic powder dispersed within a thermoplastic polymer. Second, the polymer is burned out, and the resulting porous greenbody is sintered to a dense ceramic body having a same shape. Third and finally, referring to FIG. 6, grinding machines 30 are used to grind the first and second bearing surfaces 122 , 142 until a high degree of surface smoothness is obtained. Preferably, the first and second bearing surfaces 122 , 142 are ground at a same time by two respective grinding bits 32 of two grinding machines 30 . This not only saves manufacturing time, but also reduces manufacturing error. This is because the bearing sleeve 10 only needs to be fixed on a work table a single time.
[0027] The grinding process only needs to be applied to the first and second bearing surfaces 122 , 142 of the first and second bearing blocks 120 , 140 , with the first and second bearing blocks 120 , 140 being located at the opposite first and second ends of the bearing sleeve 10 . Therefore, when the first and second bearing surfaces 122 , 142 are ground by the respective grinding bits 32 of the grinding machines 30 , the grinding bits 32 do not have to penetrate very far into the bearing sleeve 10 . Accordingly, the grinding bits 32 are subjected to reduced diametrical forces produced by the bearing sleeve 10 , and the precision of manufacturing the bearing sleeve 10 is effectively increased. In addition, production of the bearing sleeve 10 is speedier and more efficient, because of the relatively small sizes of the first and second bearing surfaces 122 , 142 that are ground.
[0028] In the preferred embodiment of the present invention, the whole of the bearing sleeve 10 is made of ceramic material. In an alternative embodiment, only portions of the bearing blocks 120 , 140 at the first and second bearing surfaces 122 , 142 are made of ceramic material.
[0029] It is understood that the invention may be embodied in other forms without departing from the spirit thereof. The above-described examples and embodiments are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given above.
|
A ceramic bearing assembly includes a shaft ( 20 ), and a bearing sleeve ( 10 ) rotatably receiving the shaft. The bearing sleeve includes an inside wall. First and second bearing blocks ( 120, 140 ) are formed at the inside wall at first and second ends of the bearing sleeve respectively. The first bearing blocks are arranged in circular fashion, and the second bearing blocks are arranged in circular fashion complementarily offset from the first bearing blocks. Each of the first and second bearing members defines a concave bearing surface ( 122, 142 ), the bearing surfaces cooperatively supporting the shaft therebetween.
| 5
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. application Ser. No. 13/412,656 filed Mar. 6, 2012, which is a division of U.S. application Ser. No. 12/264,962 filed Nov. 5, 2008, now abandoned, the entire contents of each of which is incorporated by reference herein.
TECHNICAL FIELD
[0002] The present invention relates to a composite engineered wood material piece and its method of fabrication. The wood material piece has a top wood layer secured to a substrate layer provided with the grooves which are sized and oriented such as to substantially eliminate the effects of telegraphy in the top finished surface of the top wood layer.
BACKGROUND ART
[0003] It is well known in the prior art to fabricate wood boards, particularly for the construction of wood floors, wherein the wood boards are formed from solid wood or laminated wood which contains grooves in the back surface thereof whereby to enhance the flexibility of the boards. It is also known to fabricate wood flooring strips having small wooden slats glued to the backside thereof at regular spaced intervals to add additional flexibility to the floor board. The desired flexibility of floor boards is that they can conform to irregularities in the subfloor to which the boards are to be secured. Generally these floor boards are of thicknesses of inch up to about 1 inch and provided with tongue and grooves whereby to engage one another in a side-by-side and end-to-end relationship. Such boards and the disadvantages of the related prior art are discussed for example in U.S. Pat. No. 5,283,102 issued on Feb. 1, 1994.
[0004] In recent years, laminated wood boards have become thinner with the top solid wood layer also becoming thinner normally in the range of about ⅛ inch and such laminated wood boards are installed directly on a solid wood floor or on a sound absorbing material secured to the subfloor. Transverse grooves are formed in the substrate layer of these laminated boards to provide the desired flexibility of the boards to facilitate installation thereof. However, because the top wood layer is relatively thin as compared to the substrate layer to which it is secured, the grooves formed in the substrate layer become visible in the top surface of the top wood layer by the phenomenon of telegraphy. Accordingly, the grooves need to be made very shallow and the top surface of the top wood layer is preferably of light tone or provided with a non-lustre varnish in an attempt to try to conceal the appearance or reflection of these grooves in the top surface. Therefore, laminated products have been constructed with the top wood layer having a thickness ratio in the range of one-to-one with respect to the substrate and thus affecting the flexibility of the wood board and increasing the cost thereof.
SUMMARY OF THE INVENTION
[0005] It is a feature of the present invention to provide a composite engineered wood material piece and method of fabrication which substantially overcomes the above-mentioned disadvantages of telegraphy.
[0006] According to the above feature, from a broad aspect, the present invention provides a composite engineered wood material piece which is comprised of a top wood layer secured to a substrate layer by binding means. The substrate layer has a plurality of grooves formed therein from a bottom surface thereof to enhance the flexibility of the wood material piece. The grooves are spaced from one another by one or more predetermined space distances and have one or more predetermined depth and width calculated based on parameters of the material piece to substantially eliminate the effects of telegraphy of the grooves on a top finished surface of the top wood layer.
[0007] According to a further broad aspect of the present invention, there is provided a method of fabricating a composite engineered wood material piece having a top wood layer secured to a substrate layer by binding means. The method comprises the steps of calculating from known parameters of the top wood layer and substrate layer, the depth, width and spacing of the grooves to be formed in a bottom surface of the substrate layer to enhance the flexibility of the wood material layer while substantially eliminating the effects of telegraphy of the grooves on a top finished surface of the top wood layer. The method further comprises forming a plurality of grooves in the bottom surface of the substrate layer having dimensions and spacing as calculated from the known parameters.
[0008] According to a further broad aspect, the predetermined depth and width and spacing of the grooves, in accordance with the present invention, are effected by the analysis of the following parameters: a) the type of wood of the top wood layer, b) the intrinsic properties of the substrate layer, c) the thickness ratio between the top wood layer and the substrate layer, d) the top surface texture of the top wood layer, e) the properties of the binding means, and f) the type of finish coating to be applied to a top surface of the top wood layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:
[0010] FIG. 1 is a fragmented perspective view of a section of a composite engineered wood material piece constructed in accordance with the present invention;
[0011] FIG. 2 is a side view of an example of a composite engineered wood material piece constructed in accordance with the present invention;
[0012] FIG. 3A is a perspective top view of a top wood layer to be secured to a substrate layer and formed of oak material having a clearly defined and visible grain surface texture;
[0013] FIG. 3B is a perspective view similar to FIG. 3A but showing a top wood layer fabricated from a different type of wood, herein maple wood having a faint wood grain; and
[0014] FIG. 4 is a plan view of the rear surface of a composite engineered wood material piece having grooves therein formed of different spacing, size and orientation to provide a sheet adapted to be cut to a template shape to produce a contoured sheet having different flexible regional characteristics to form a top surface of a shaped member, such as an article of furniture, an irregularly shaped wall surface or a multitude of other articles.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0015] Referring now to the drawings and more particularly to FIG. 1 , there is shown generally at 10 a composite engineered wood material piece such as a floor board or slats constructed in accordance with the prior art and which comprises a top wood layer constructed of a superior material such as oak, pine or maple and secured by a glue layer 12 to a substrate layer 13 . Grooves 14 are formed in the substrate material 13 from a bottom surface 15 thereof and at spaced intervals whereby to provide flexibility to the floor board 10 . As previously described, such grooves 14 , through the phenomenon of telegraphy, form shaded zones 16 in the top finished surface 17 of the top wood layer 11 .
[0016] The present invention addresses this phenomenon of telegraphy and substantially eliminates the effects thereof on the top finished surface 17 . This is achieved by calculating the dimension of the depth and width as well as the spacing of the grooves from a set of parameters of the top wood layer and the substrate layer. These parameters include the type of wood of the top wood layer, the intrinsic properties of the substrate layer, the thickness ratio between the top wood layer and the substrate layer, the top surface texture of the top wood layer, the properties of the binding means and the type of finish coating to be applied to a top surface of the top wood layer. All of these parameters have an interrelationship with respect to one another and produce the resulting telegraphy. It has been ascertained that this telegraphy is caused by four phenomenon and namely the induced tension within the composite laminated material piece, the deformation of the composite material piece caused by deflection when it is installed on a irregular subsurface, the change in humidity in the composite material piece causing it to expand and retract, and the dispersion or conduction of humidity throughout the composite wood material piece.
[0017] Because the composite engineered wood material piece of the present invention is comprised of two distinct laminated wood materials, namely a top wood layer 11 of wood material and a substrate layer comprised of laminated or compressed inferior wood material glued together or other suitable type of substrate. These glued materials will be subject to tension and stress which will produce the telegraphy of the grooves formed in the bottom surface thereof. The ratio between the thickness of the top wood layer 11 and the substrate layer 13 is an important factor in determining the spacing 18 , see FIG. 1 , between the grooves 14 . If the ratio between the thickness of the top wood layer 11 and that of the substrate layer 13 is close to 1 , the telegraphy of the grooves will be very weak due to the thickness of the top wood layer 11 which is less conductive. However, if the ration between the top wood layer and the substrate layer is 1:10, the telegraphy would be greatly amplified as the top wood layer is very thin compared to the substrate layer. Accordingly, the spacing 18 between the grooves will require to be closer to one another and the dimension of the depth 19 of the groove would have to be shorter. The width 20 of the grooves may also be made narrower.
Example 1
[0018] If the top wood layer 11 has a thickness of 8 mm and the substrate layer 13 has a thickness of 8 mm, the telegraphy of the grooves 14 formed in the substrate layer is nearly inexistent for the reason that the substrate layer cannot have much effect on the top wood layer which is of equal thickness. However, if the top wood layer is of 1 mm thickness and the substrate layer much thicker, say 8 mm, the telegraphy of the grooves would be very visible. Therefore, the ratio between the thickness of the top wood layer and the substrate layer is an important factor to consider in the determination of the configuration and spacing of the grooves.
Example 2
[0019] Considering now two top wood layers 11 , one of 2 mm and one of 4 mm, glued on a 6 mm thick substrate and with the grooves being spaced-apart 2 inches and having a depth of 4 mm. The groove telegraphy in the 2 mm top wood layer will be very visible. Accordingly, the spacing between the grooves will need to be reduced to 1 inch to reduce substantially the telegraphy. However, for the top wood layer of 4 mm a groove spacing of 1½ inches would be sufficient to obtain an acceptable level of reduction of the telegraphy.
[0020] Another important factor to consider is the binding material which is preferably a glue coating applied between the top wood layer 11 and the substrate layer 13 with further application of pressure by means of presses, as is well known in the art. The adhesive material can also be polyurethane foam or contact cement applied to opposed surfaces to be mated and let dry before the layers are contacted under pressure. The adhesive binder or glue 12 has a predetermined elastic property and thickness and such is also a factor in the determination of the predetermined spacing 18 of the grooves 14 . Glue which is very flexible will permit a spacing 18 between the grooves which is larger or permit a depth of groove which is deeper as the glue acts as a relaxation zone for the constraints of the substrate layer. The glue, or other binding agent, could also acts as vapour barrier and reduces the transmission of humidity.
[0021] Another important factor taken into consideration is the depth 19 of the grooves 14 . The ratio between the depth 19 of the grooves 14 and the thickness of the substrate layer 13 has an impact on the telegraphy and the flexibility of the wood material piece 10 . For a top layer to substrate layer ratio of 1:8 and less, the wood material piece 10 would have less flexibility and less telegraphy. Depending on the nature of the substrate layer, it has been ascertained that a certain flexibility can be achieved with a ratio of 1:3 but the telegraphy phenomenon will be increased. In order to reduce telegraphy, the spacing 18 between the grooves will be reduced as above-mentioned. It is pointed out that a ratio of 7:8 can provoke important telegraphy in the top finished surface of the top layer.
[0022] The depth 19 of the grooves also has a negative effect in that it defuses humidity within the substrate layer and can provoke increased telegraphy on the top surface 17 of the top wood layer 11 . Although the glue layer 12 and the glue present in the substrate provide a barrier to humidity, this barrier is broken at each groove 14 . As pointed out herein above the reason for the grooves is to diminish the rigidity of the composite material piece or layer in order to facilitate installation on irregular subsurfaces.
Example 3
[0023] With reference to FIG. 2 , there is shown a specific composite engineered wood material piece 10 ′ constructed in accordance with the present invention. The top wood layer 11 is formed of maple wood and has a thickness of 4 mm. The substrate layer 13 is formed of birch wood and has a thickness of 9 mm. If the grooves 14 ′ have a depth of 2 mm, the telegraphy in the top finished surface 17 is practically invisible. However, if the grooves 14 ″ have a depth of 8 mm, for the same groove width, the telegraphy would be very visible in the top finished surface 17 . However, the grooves 14 ′ are not deep enough to provide the desired flexibility of the composite wood material piece 10 .
[0024] Another important factor taken into consideration is the composition of the substrate layer 13 . The intrinsic properties of the substrate layer 13 have an important effect on telegraphy. Substrate layers of material all have a specific density and modulus of elasticity and hygroscopic properties as well as other characteristics. By the formation of grooves in the substrate layer, there is created constraints in the substrate layer which are manifest on the top finished surface of the top wood layer. A substrate material which has a high hygroscopic movement will be, affected substantially by the formation of grooves and would have a greater impact on the appearance of the grooves on the top surface of the top wood layer. Accordingly, rigidity of the substrate layer affects telegraphy. The tensions which exit in certain substrate materials due to their lamination and the orientation of wood particles and fibres, can also provoke telegraphy when grooves are formed in such material. As above-described, the humidity barrier characteristic of the substrate is also an important factor.
Example 4
[0025] We will now consider the effects of a top wood layer 11 having a thickness of 4 mm secured to two types of substrate layer 13 , namely a substrate layer constructed of MDF material and having a thickness of 8 mm as compared to a substrate layer of the same thickness but fabricated from plywood material. During humidity variations, the MDF substrate layer will have more important dimensional instability and will provoke more telegraphy when compared to the plywood sheet substrate which has a greater dimensional stability. Thus, the composite material which has a substrate layer having a greater modulus of elasticity will provoke increased telegraphy on the finished surface of the top wood layer as there will be more deformation in the surrounding area of the grooves.
[0026] Another factor to consider in the determination of the configuration and spacing of the grooves is the top surface texture of the top wood layer. FIG. 3A shows a top wood layer formed of oak material which is a very rigid wood material having a very high modulus of elasticity and such with therefore greatly reduce the telegraphy of the grooves. The oak wood has a pronounced textured grain 26 which also conceals defects in the top finished surface 17 . When the wood material pieces are used as floor boards, one or more coats of varnish are applied to the top surface 17 for shine and durability. It has been found that a glossy surface is more conductive of the telegraphy phenomenon that is a less glossy surface. Also, if a stain is applied to the top surface of the top wood layer, the darker the stain, the more visible becomes any telegraphy and this may also be taken into consideration when calculating the size and spacing of the groove.
Example 5
[0027] As described above with reference to FIG. 3A and 3B , there is shown the oak material top layer 25 which is darker and provided with a pronounced textured grain and a maple wood top layer 27 which is lighter and contains less grain. The maple top wood layer 27 will show more telegraphy than the oak layer. Both top wood layers 25 and 27 have a thickness of 2 mm and are secured to a same substrate layer. It has been found that the maple top wood layer produces a more important telegraphy than does the oak layer 25 . Also, the textured grain 28 in the maple wood 27 is less pronounced and visible and therefore provides less camouflage to any telegraphy transmission in the wood material.
Example 6
[0028] Considering now a top wood layer of oak material having a natural colour with a mat finish on its top surface as opposed to a top wood layer of maple which is stained a dark color and provided with a high lustred finish on its top surface. Both top wood layers are 4 mm in thickness and are glued onto a substrate layer formed of birch and having a thickness of 9 mm and grooves having a depth of 6 mm and a width of 2 mm. The grooves are also spaced apart 1½ inch. When comparing both products it has been found that the oak material top layer provides an adequate reduction of the telegraphy of the grooves on its top surface. Accordingly, it would be possible to utilize a glue which is less flexible or to have the grooves spaced a greater distance apart, about 1½ inches. However, with the dark stain maple wood top layer, the telegraphy was slightly apparent. Therefore, a reduction in the spacing between the grooves would be necessary to greatly reduce this telegraphy, a spacing of 1⅛ inch.
[0029] In conclusion, the finish coating applied to the top surface of the top wood layer 11 has an impact on telegraphy. A finished coating which has less lustre will produce less telegraphy than does a high lustre surface as above-mentioned. However, high lustre surfaces are the preferred surfaces of floor wood board, furniture, wall decorations, etc., and accordingly, it is important to therefore configure the grooves such as to substantially eliminate or greatly reduce the telegraphy phenomenon.
[0030] A further factor for consideration is the determination of the width 20 of the grooves 14 . A very narrow groove width produces very little telegraphy. For the laminated wood boards as above-described, it has been found that a width of 1 to 2 mm provokes an average telegraphy whereas a width which is greater than 3 mm or more than 4 mm will enhance telegraphy. There is therefore a proportional relationship between the transmission of telegraphy and the groove width.
[0031] As mentioned, another consideration in reducing telegraphy is the spacing 18 between the grooves. Generally speaking, a spacing of more than 2 inches greatly increases telegraphy depending of course on the depth and width of the grooves. A spacing of 1¼ inches or less will improve the reduction of telegraphy and it has been found that a spacing of about one inch is more desirable as it further reduces telegraphy. However, the amount of grooves should be limited not to greatly affect the modulus of elasticity of the substrate material.
Example 7
[0032] For a composite material piece having a substrate layer formed of birch material and of a thickness of 9 mm, and a top surface layer of maple having a thickness of 4 mm with a glossy surface coating, grooves having a width of 2 mm and a depth of 6 mm would be desirable. However, with such a product specification, the risk of telegraphy is highly present as we have a ratio of thickness between the top wood layer and the substrate layer of 4:9, a ratio of groove depth of 6:9, a rigid modulus of elasticity of the substrate, and a glossy top surface finish on the maple top wood surface. Also, any humidity will provoke deformation in the wood material. Therefore, a spacing between the grooves of 2 inches will make the grooves very visible on the top surface by telegraphy. By decreasing the spacing to about 1⅛ inch, the telegraphy is practically non-visible and the grain in the top maple wood layer becomes more visible due to the practically non-existing phenomenon of the telegraphy. By reducing the spacing between the grooves to about 1 inch, the grain becomes more visible and the surface is almost unaffected by telegraphy.
[0033] Referring now to FIG. 4 , there is shown a composite engineered wood material piece, herein a sheet of material, formed in accordance with the present invention. As hereinshown, the rear surface 31 of the substrate layer 32 is provided with grooves oriented in groups, namely groups 33 and and wherein the orientation of the grooves 33 ′ of group 33 and grooves 34 ′ of Group 34 extend at different angles whereby to provide different zones and orientation of flexibility to the layer. Also, the grooves 34 ″ in group 34 are more closely spaced in a section of the group 34 to provide added flexibility in that section. Such an engineered composite layer may be formed for specific applications and wherein the layer may be cut to the shape of a template, such as indicated by phantom line 35 , to form an overlay sheet for a repetitive product, such as an article of furniture wherein the sheet is to be bent to conform to a certain shape. The spacing and dimension of the grooves is also calculated to substantially eliminate or greatly reduce the phenomenon of telegraphy. It is pointed out that the grooves can be formed by various means, such as by the use of a saw, a router bit, a slitting blade, or by spaces between glued material strips.
[0034] It is within the ambit of the present invention to cover any obvious modifications of the preferred embodiment described herein, provided such modifications fall within the scope of the appended claims.
|
The described method of fabricating a composite engineered wood material floor board, having a top wood layer secured to a wood material substrate layer, minimizes the effect of telegraphy in the resulting floor board. The method includes selecting a top wood layer from a top surface quality wood material having a thickness of between 1 mm to 8 mm, and selecting a substrate wood material layer having a thickness of between 6 mm and a thickness ratio of 1 to no more than 10 between the top wood layer and the substrate wood material layer. A plurality of transverse rectangular spaced-apart grooves are also formed in a bottom surface of said wood substrate layer. The ratio between the depth of said grooves and the thickness of the substrate wood material has an impact on telegraphy of said grooves in said top wood layer and is therefore selected accordingly.
| 8
|
This is a continuation application under 37 CFR 1.62 of prior application Ser. No. 08/091,396 filed Jul. 13, 1993 (aban.), which is a cont. 07/635,818 filed Jan. 2, 1991 (aban.) which is a cont. of 07/234,899 filed Aug. 22, 1988 (aban.)
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to automatic white balance adjusting devices in image sensing apparatus such as video cameras or electronic still cameras.
2. Description of the Related Art
On the automatic white balance adjusting device for the video camera or the like, a wide variety of proposals are being made at present, including those using the color temperature sensor, or the video signal. Of these, a conventional example of the automatic white balance adjusting device using the video signal is described with reference to FIG. 1.
FIG. 1 is a block diagram roughly illustrating the video signal dependent automatic white balance adjusting device which was reported at the national convention of the Television Society in Japan held in the year 1986. The device includes an image pickup element 1, a luminance signal and color signal generating circuit 2, gain control circuits 3 and 4, a color-difference signal generating circuit 5, an encoder 6, gate circuits 7 and 8, clipping circuits 9 and 10, an R-B signal detecting circuit 11, an averaging circuit 12, a comparison amplifier 13 and a tracking correction circuit 14. The gate circuits 7 and 8 through the tracking correction circuit 14 constitute an automatic white balance adjusting circuit 15. In the device of FIG. 1, a light signal entering the image pickup element 1 is photoelectrically converted to an electrical signal which is applied to the luminance signal and color signal generating circuit 2. In the aforesaid luminance signal and color signal generating circuit 2, a luminance signal Y H having a luminance signal band, another luminance signal Y L of color signal band, and a color signal R (Red) and another color signal B (Blue) are generated. The color signal R and the color signal B are applied respectively to the gain control circuits 3 and 4, in which they are amplified by a control signal from the tracking correction circuit 14, and from which they are produced as a color signal R' and a color signal B' respectively. These signals R' and B' are applied along with the aforesaid luminance signal Y L to the color-difference signal generating circuit 5 in which color-difference signals (R-Y L ) and (B-Y L ) are generated. The color-difference signals (R-Y L ) and (B-Y L ) are applied along with the luminance signal Y H to the encoder 6. From these inputs, a standard television signal is then generated to be output. Here, the above-described color-difference signals (R-Y L ) and (B-Y L ) are applied also to the automatic white balance adjusting circuit 15.
The color-difference signals (R-Y L ) and (B-Y L ) are applied to the gate circuits 7 and 8 respectively, wherein the unnecessary signal in the blanking period, the abnormal color-difference signal due to the signal collapse at the time of high brightness shooting, etc. are removed. Signals produced from the gate circuits 7 and 8 are applied to the clipping circuits 9 and 10 respectively, wherein any of the color-difference signals which exceed the level for an actually usable color temperature range is clipped, and supplied therefrom to the R-B signal detecting circuit 11, wherein a signal (R-B) is detected by taking difference between the outputs (R-Y L )' and (B-Y L )' from the clipping circuits 9 and 10. In the averaging circuit 12, the signal (R-B) from the R-B signal detecting circuit 11 is averaged, thus being converted to a D.C. signal. In the comparison amplifier 13, the signal from the averaging circuit 12 is compared with a reference voltage Vref. A corresponding signal to this comparison is output to the tracking correction circuit 14. In the tracking correction circuit 14, control signals for controlling the gains of the above-described gain control circuits 3 and 4 so as to correct the white balance are generated on the basis of the signal from the comparison amplifier 13. These control signals are output to the above-described gain control circuits 3 and 4. Since a negative-feedback loop is thus formed, the above-described white balance-adjusted color-difference signals can be supplied to the encoder 6.
With such a conventional device as described above, for the light of the sort which approximately comes under Planck's radiation law, such as the sun light or the light from a halogen lamp, when the object to be photographed is white, the values of the signals (R-Y L ) and (B-Y L ) both become zero. Hence, the condition in which the white balance is proper can be established. But, in the case of a light source such as fluorescent lamp, because its intensity distribution over spectrum is different from Planck's radiation law, while the value of the signal (R-B) becomes zero, the values of the signals (R-Y L ) and (B-Y L ) do not become zero, thus giving rise to a problem that the proper white balance cannot be established.
SUMMARY OF THE INVENTION
This invention has been made in order to eliminate such a problem and its object is to provide an automatic white balance adjusting device in which whether an illumination light source approximately comes under Planck's radiation law or not, the white balance can be properly adjusted.
To achieve the above-described object, in an embodiment of the invention, the automatic white balance adjusting device comprises first detecting means for detecting a first signal representing the difference between signal components of two color-difference signals (R-Y L ) and (B-Y L ) obtained from color signals, first comparing means for comparing the first signal output from the first detecting means with a first reference voltage adjusted to be equal to a D.C. voltage obtained when the first signal becomes zero, first changeover means, responsive to an output of the first comparing means, for selecting one of a second reference voltage and a third reference voltage which are preset depending on a positive or negative sign of the first signal, first averaging means for averaging an output of the first changeover means, a tracking correction circuit for producing outputs corresponding to an output of the first averaging means, second detecting means for detecting a second signal representing the sum of the signal components of the two color-difference signals, second comparing means for comparing the second signal output from the second detecting means with a fourth reference voltage adjusted to be equal to a D.C. voltage obtained when the second signal becomes zero, second changeover means, responsive to an output of the second comparing means, for selecting one of a fifth reference voltage and a sixth reference voltage which are preset depending on a positive or negative sign of the second signal, second averaging means for averaging an output of the second changeover means, and adding means for adding an output of the second averaging means and one of the outputs of the tracking correction circuit, wherein gains for the color signals are controlled by an output of the adding means and another of the outputs of the tracking correction circuit.
By having the above-described feature, regardless of whether or not an illumination light approximately comes under Planck's radiation law, a proper automatic white balance adjustment can be carried out.
Also, to achieve the above-described object, in another embodiment of the invention, the automatic white balance adjusting device comprises first computing means for computing color signals, means for producing control signals for controlling gains for the color signals on the basis of a signal output from the first computing means, second computing means for computing the color signals in a different operation from that of the first computing means, and means for correcting the control signals on the basis of a signal output from the second computing means.
Also, to eliminate such a conventional problem as described before, in still another embodiment of the invention, the automatic white balance adjusting device comprises first detecting means for detecting a first signal representing the difference between signal components of two color-difference signals obtained from color signals, first comparing means for comparing the first signal output from the first detecting means with a first reference voltage adjusted to be equal to a D.C. voltage obtained when the first signal becomes zero, first changeover means, responsive to an output of the first comparing means, for selecting one of a second reference voltage and a third reference voltage which are preset depending on a positive or negative sign of the first signal, first averaging means for averaging an output of the first changeover means, a first tracking correction circuit for producing an output for an R signal system and an output for a B signal system in response to an output of the first averaging means, second detecting means for detecting a second signal representing the sum of the signal components of the two color-difference signals, second comparing means for comparing the second signal output from the second detecting means with a fourth reference voltage adjusted to be equal to a D.C. voltage obtained when the second signal becomes zero, second changeover means, responsive to an output of the second comparing means, for selecting one of a fifth reference voltage and a sixth reference voltage which are preset depending on a positive or negative sign of the second signal, second averaging means for averaging an output of the second changeover means, a second tracking correction circuit for producing an output for the R signal system and an output for the B signal system in response to an output of the second averaging means, a first adder for adding the outputs for the R signal system among the outputs of the first and second tracking correction circuits, and a second adder for adding the outputs for the B signal system, wherein gains for the color signals are controlled by outputs of the first and second adders.
Also, to achieve the above-described object, in a further embodiment of the invention, the automatic white balance adjusting device comprises first detecting means for detecting a first signal representing the difference between signal components of color-difference signals obtained from color signals, first averaging means for averaging the first signal output from the first detecting means, first comparing means for comparing an average signal output from the first averaging means with a first reference voltage adjusted to be equal to a D.C. voltage obtained when the first signal becomes zero, a tracking correction circuit for producing outputs corresponding to an output of the first comparing means, second detecting means for detecting a second signal representing the sum of the signal components of the two color-difference signals, second averaging means for averaging the second signal output from the second detecting means, second comparing means for comparing an average signal output from the second averaging means with a second reference voltage adjusted to be equal to a D.C. voltage obtained when the second signal becomes zero, and adding means for adding an output of the second comparing means and one of the outputs of the tracking correction circuit, wherein a gain for one of the color signals is controlled by another of the outputs of the tracking correction circuit, and wherein a gain for another of the color signals is controlled by an output of the adding means.
Other objects and features and advantages of the invention will become apparent from the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram roughly illustrating the conventional automatic white balance adjusting device using video signals.
FIG. 2 is a block diagram illustrating the arrangement of the main parts of a first embodiment of an automatic white balance adjusting device according to the invention.
FIG. 3 is a block diagram roughly illustrating the arrangement of the parts of a second embodiment of the automatic white balance adjusting device according to the invention.
FIG. 4 is a block diagram illustrating the arrangement of the main parts of a third embodiment of the automatic white balance adjusting device according to the invention.
FIG. 5 is a block diagram illustrating the arrangement of the main parts of a fourth embodiment of the automatic white balance adjusting device according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2 is a block diagram illustrating the arrangement of the main parts of the automatic white balance adjusting device which is the first embodiment of the invention. In FIG. 2, terminals K, L, M and N correspond to those of the conventional device shown in FIG. 1. An automatic white balance adjusting circuit 26 in FIG. 2 corresponds to the above-described automatic white balance adjusting circuit 15 in FIG. 1. The other same or like parts as those shown in FIG. 1 are denoted by the same reference numerals.
In the device of FIG. 2, the color-difference signals (R-Y L ) and (B-Y L ) produced from the color-difference signal generating circuit 5 are output respectively through the terminals M and N to an R-B signal detecting circuit 16 and an Mg-G signal detecting circuit 21.
In the R-B signal detecting circuit 16, taking the difference between the color-difference signals (R-Y L ) and (B-Y L ), a signal (R-B) as the first signal is produced. A comparison amplifier 17 is a device for comparing the signal (R-B) with a first reference voltage Vref1. This voltage Vref1 is adjusted so as to be equal to a D.C. voltage obtained when the signal (R-B) becomes zero. Here, it is assumed in this embodiment that when R>B, the output of the comparison amplifier 17 becomes "H" level, and when R<B, it becomes "L" level. 18 is an changeover circuit which is a device for selectively outputting one of predetermined second and third reference voltages Vref2 and Vref3 when the output of the comparison amplifier 17 is "H" level or "L" level, respectively. That is, when the output of the R-B signal detecting circuit 16 represents R>B, or when the color temperature of the illumination light is low, it outputs the second reference voltage Vref2. When representing R<B, it outputs the third reference voltage Vref3. An averaging circuit 19 is a device for averaging an output of the changeover circuit 18. The averaging circuit 19 takes a certain value in between the second reference voltage Vref2 and the third reference voltage Vref3; when the color temperature of the illumination light is low, it takes a nearer value to the second reference voltage Vref2; and as the color temperature increases, it becomes to take a nearer value to the third reference voltage Vref3. When the output of the averaging circuit 19 is near to the second reference voltage Vref2, or when the color temperature is low, a tracking correction circuit 20 produces a control signal for decreasing the gain for the gain control circuit 3 and another control signal for increasing the gain for the gain control circuit 4. Conversely when it is nearer to the third reference voltage Vref3, or when the color temperature is high, the tracking correction circuit 20 produces a control signal for increasing the gain of the gain control circuit 3 and another control signal for decreasing the gain of the gain control circuit 4. In this connection, it should be noted that these two control signals have a relationship that the white balance is properly adjusted in the actually usable color temperature range (for example, 2800° K.-8000° K.) for that light source which approximately comes under Planck's radiation law.
In the Mg-G signal detecting circuit 21 (Mg: Magenta; G: Green), taking the sum of the color-difference signals (R-Y L ) and (B-Y L ), a signal (R+B-2Y L ) as the second signal is produced. A comparison amplifier 22 is a device for comparing the signal (R+B-2Y L ) produced from the Mg-G signal detecting circuit 21 with a fourth reference voltage Vref4. This fourth reference voltage Vref4 is adjusted so as to be equal to a D.C. voltage obtained when the signal (R+B-2Y L ) becomes zero. Here it is assumed in this embodiment that when R+B>2Y L , the output of the comparison amplifier 22 becomes "H" level, and when R+B<2Y L , it becomes "L" level. 23 is a changeover circuit for selectively outputting one of predetermined fifth and sixth reference voltages Vref5 and Vref6 when the output of the comparison amplifier 22 is "H" level or "L" level, respectively. That is, at this time, when the output of the Mg-G signal detecting circuit 21 represents R+B>2Y L , the fifth reference voltage Vref5 is output. Also, when the illumination light approximately comes under Planck's radiation law, R+B≈2Y L . Therefore, a near value to (Vref5+Vref6)/2 is output. An averaging circuit 24 is a device for averaging the output signal from the changeover circuit 23. The averaging circuit 24 takes a certain value in between the fifth and sixth reference voltages Vref5 and Vref6. This value varies depending on the degree of divergence of spectral radiations of the illumination light. In an adder 25, one of the control signals from the tracking correction circuit 20 and the output from the averaging circuit 24 are added. Here, when the illumination light is of the light source which approximately comes under Planck's radiation law, the output signal from the averaging circuit 24 is almost constant. At this time, the two control signals to be output to the gain control circuits 3 and 4 are set so as to become an optimum relation to the variation of the color temperature of the illumination light by the tracking correction circuit 20 and the adder 25. Also, when the output signal from the Mg-G signal detecting circuit 21 represents R+B>2Y L , the output signal from the averaging circuit 24 has a nearer value to the reference voltage Vref5 than the output signal produced when the above-described illumination light is of the light source which approximately comes under Planck's radiation law. At this time, the output signal from the adder 25 has such a characteristic as to make smaller the gain of the gain control circuit 4 than the output signal produced when the above-described illumination light approximately comes under Planck's radiation law. Also, conversely when the output signal of the Mg-G signal detecting circuit 21 represents R+B<2Y L , the adder 25 produces such a control signal as to make large the gain for the gain control circuit 4. In the gain control circuits 3 and 4, gain-controlled signals R' and B' according to the control signals from the tracking correction circuit 20 and the adder 25 are input to the color-difference signal generating circuit 5. In the color-difference signal generating circuit 5, color-difference signals (R-Y L ) and (B-Y L ) are formed by the signals R' and B' and the luminance signal Y L of the low band, and supplied to the encoder 6 and the automatic white balance adjusting circuit 26.
In such a manner, the color-difference signals whose white balance is adjusted mainly by the tracking correction circuit 20 in a case where the illumination light approximately comes under Planck's radiation law, or properly adjusted by the work of the tracking correction circuit 20 and the averaging circuit 24 in a case where the illumination light does not approximately come under Planck's radiation law, can be supplied to the encoder 6.
Also, in this embodiment, the width of the output signal from the averaging circuit 24 may be narrowed by a limiter to such an extent that when, for example, the fluorescent lamp (white color) issues the illumination light, the white balance is adjusted correctly, so that an automatic white balance adjusting device which is not very susceptible to the influence of the green of the leaves of trees in the picture, etc. can be realized.
Also, in this embodiment, the arrangement is such that the white balance is adjusted by controlling the gains for the color signals R and B. Yet, in other methods, for example, even by the arrangement that the low band luminance signal is added to, or subtracted from, the color signal at some rate, the white balance adjustment can be easily embodied.
Further, the color-difference signals may be supplied through the above-described gate circuits 7 and 8 and the clipping circuit 9 and 10 of the conventional example to the R-B signal detecting circuit 16 and the Mg-G signal detecting circuit 21.
Also, though, in this embodiment, for the control signal to be applied to the gain control circuit 4, the output signal from the tracking correction circuit 20 and the output signal from the averaging circuit 24 after having been added by the adder 25 have been used, it is of course good to use the gain control signal from the adder 25 not for the gain control circuit 4, but for the gain control circuit 3.
Also, though, in this embodiment, the two color signals (R-B) and (R+B-2Y L ) have been produced by computing the two color-difference signals (R-Y L ) and (B-Y L ), the above-described two color signals may be different color signals from each other, both of which become zero in the case when R-Y L =0 and B-Y L =0 hold.
Next, FIG. 3 is a diagram illustrating a second embodiment of the invention, wherein the same reference numerals as those of FIG. 1 and FIG. 2 denote the same elements.
In the device of FIG. 3, after the above-described color-difference signals (R-Y L ) and (B-Y L ) produced by the color-difference signal generating circuit 5 have been applied through the terminals M, N to the R-B signal detecting circuit 16 and Mg-G signal detecting circuit 21, averaging circuits 27 and 28 average respectively the above-described output signals (R-B) and (R+B-2Y L ) from the R-B signal detecting circuit 16 and the Mg-G signal detecting circuit 21. In the comparison amplifier 17, the output signal from the averaging circuit 27 is compared with a first reference voltage Vref1', and the result is amplified and output. Here, the first reference voltage Vref1' is adjusted so as to be equal to a D.C. voltage obtained when the R-B signal becomes zero. In a first tracking correction circuit 29, when the output of the comparison amplifier 17 represents R>B, a control signal for making small the gain of the above-described gain control circuit 3 and another control signal for making large the gain of the above-described gain control circuit 4 are produced. Conversely when it represents R<B, the reverse operation, that is, a control signal for making large the gain of the gain control circuit 3 and another control signal for making small the gain of the gain control circuit 4 are produced. Further, the two control signals to be input to the terminals K and L have a relationship that the white balance is adjusted correctly in an actually usable color temperature range (for example, 2800° K.-8000° K.) for the light source which approximately comes under Planck's radiation law.
In the comparison amplifier 22, the result of comparison of the output signal from the averaging circuit 28 with a second reference voltage Vref2' is output. Here, the second reference voltage Vref2' is adjusted so as to be equal to a D.C. voltage obtained when the signal (R+B-2Y L ) becomes zero. In a second tracking correction circuit 30, when the output of the comparison amplifier 22 represents R+B>2Y L , a control signal for making small the gain of the gain control circuit 3 and another control signal for making small the gain of the gain control circuit 4 are produced. Conversely when it represents R+B<2Y L , the reverse operation to that described above, that is, a control signal for making large the gain of the gain control circuit 3 and another control signal for making large the gain of the gain control circuit 4 are produced. Also, in the case when the illumination light in the visible light region approximately comes under Planck's radiation law, R+B÷2Y L results. At this time, therefore, the two control signals take some predetermined values. When the illumination light does not approximately come under Planck's radiation law, for example, in the case of the fluorescent lamp, R+B≈2Y L results. Therefore, control signals other than the above-described predetermined values are output.
Adders 31 and 32 add the control signals from the first tracking correction circuit 29 and the control signals from the second tracking correction circuit 30 respectively to each signal of the R signal system, B signal system, and output them to the gain control circuits 3 and 4. In the gain control circuits 3 and 4, the gains for the above-described R signal and B signal are controlled by the control signals from the adders 31 and 32.
In the color-difference signal generating circuit 5, the above-described color-difference signals (R-Y L ) and (B-Y L ) are produced on the basis of the R' signal, B' signal from the gain control circuits 3 and 4.
As a result of the above, even under a light source which does not approximately come under Planck's radiation law, the color-difference signals (R-Y L ) and (B-Y L ) of which the white balance has been automatically adjusted are supplied to the encoder 6.
It should be noted that before the detecting circuits 16 and 21 of the above-described automatic white balance adjusting circuit 26, the above-described gate circuits 7 and 8 and the clipping circuits 9 and 10 of the automatic white balance adjusting circuit 15 may be added as shown in FIG. 1.
FIG. 4 is a block diagram roughly illustrating the arrangement of the parts of a third embodiment of the automatic white balance adjusting device according to the invention. In FIG. 4, the same reference numerals as those of FIGS. 1-3 are employed to denote the same elements.
In the device of FIG. 4, the tracking correction circuit 29, when the output of the above-described averaging circuit 19 is near the reference voltage Vref2, or the color temperature is low, produces a control signal for making small the gain of the above-described gain control circuit 3 and another control signal for making large the gain of the above-described gain control circuit 4. Conversely when it is near the reference voltage Vref3, or the color temperature is high, a control signal for making large the gain of the gain control circuit 3 and another control signal for making small the gain of the gain control circuit 4 are produced.
In this connection, it should be noted that these two control signals have a relationship that the white balance is adjusted correctly in the actually usable color temperature range (for example, 2800° K.-8000° K.) for a light source which approximately comes under Planck's radiation law.
Also, the tracking correction circuit 30, when the output of the averaging circuit 24 is near the reference voltage Vref5, produces a control signal for making small the gain of the gain control circuit 3 and another control signal for making small the gain of the gain control circuit 4. Conversely when it is near the reference voltage Vref5, a control signal for making large the gain of the gain control circuit 3 and another control signal for making large the gain of the gain control circuit 4 are produced. The adders 31 and 32 add the control signals from the tracking correction circuits 29 and 30 to each signal of the R signal system and the B signal system, and output the results to the gain control circuits 3 and 4. At this time, as has been described above, in the case when the illumination light approximately comes under Planck's radiation law, the tracking correction circuit 30 produces almost constant control signals, while the tracking correction circuit 29 produces control signals depending on the color temperature of the illumination light. In the adders 31 and 32, these control signals are added in such an addition ratio that the white balance can be adjusted correctly. In the gain control circuits 3 and 4, the gains for the color signals are controlled by the control signals from the adders 31 and 32. The outputs of the gain control circuits 3 and 4 are applied to the color-difference signal generating circuit 5. By such an arrangement, this embodiment forms a negative-feedback loop as a whole. Therefore, the color-difference signals (R-Y L ) and (B-Y L ) of which the white balance has been adjusted correctly can be supplied to the encoder 6.
FIG. 5 is a diagram illustrating a fourth embodiment of the invention, wherein the same reference numerals as those of FIGS. 1-4 are employed to denote the same elements. In this figure, the above-described color-difference signals (R-Y L ) and (B-Y L ) produced by the color-difference signal generating circuit 5 are output through the terminals M and N to the R-B signal detecting circuit 16 and the Mg-G signal detecting circuit 21.
In the R-B signal detecting circuit 16, taking the difference between the color-difference signals (R-Y L ) and (B-Y L ), a signal (R-B) as the first signal is produced. Also, in the Mg-G signal detecting circuit 21, taking the sum of the color-difference signals (R-Y L ) and (B-Y L ), a signal (R+B-2Y L ) as the second signal is produced. In the averaging circuits, 27 and 28, the output signals (R-B) and (R+B-2Y L ) respectively from the R-B signal detecting circuit 16 and the Mg-G signal detecting circuit 21 are averaged respectively. In the comparison amplifier 17 the output signal from the averaging circuit 27 is compared with the first reference voltage Vref1', and the result is amplified and output. Here, the first reference voltage Vref1' is adjusted so as to be equal to a D.C. voltage obtained when the signal (R-B) becomes zero. In the tracking correction circuit 29, when the output of the comparison amplifier 17 represents R>B, a control signal for making small the gain of the above-described gain control circuit 3 is produced. Conversely when it represents R<B, the operation is reverse to the above and a control signal for making large the gain of the gain control circuit 3 is produced.
In the comparison amplifier 22, the result of comparison of the output signal from the averaging circuit 28 with the second reference voltage Vref2' is output. Here, the second reference voltage Vref2' is adjusted so as to be equal to a D.C. voltage obtained when the signal (R+B-2Y L ) becomes zero.
Here, in the case when the illumination light approximately comes under Planck's radiation law, R+B≈2Y L results. Therefore, the output signal of the comparison amplifier 22 is at a certain constant signal level. But when R+B>2Y L , the output signal from the comparison amplifier 22 is a control signal for making small the gain of the gain control circuit 4. When R+B<2Y L , the comparison amplifier 22 produces a control signal for, conversely, making large the gain of the gain control circuit 4. An adder 33 is a device for adding one of the output signals from the tracking correction circuit 29 to the output signal from the comparison amplifier 22. Here when the illumination light is of the light source which approximately comes under Planck's radiation law, the output signal from the comparison amplifier 22 is almost constant as has been described above. At this time, the two control signals to be output to the gain control circuits 3 and 4 are set by the tracking correction circuit 29 and the adder 33 so as to become an optimum relationship to the variation of the color temperature of the illumination light. Also, when the output signal of the Mg-G signal detecting circuit 21 represents R+B>2Y L or R+B<2Y L , the output signal from the averaging circuit 28 is a different signal from the output signal obtained when the illumination light approximately comes under Planck's radiation law. At this time, the output of the adder 33 has such a characteristic as that which has been described above, when R+B>2Y L , the gain of the gain control circuit 4 is made smaller, while when R+B<2Y L , the gain of the gain control circuit 4 is made larger. And, the gain control circuits 3 and 4 control the gains of the color signals R and B according to the control signals from the tracking correction circuit 29 and the adder 33 and supplies the gain-controlled color signals R' and B' to the above-described color-difference signal generating circuit 5. The color-difference signal generating circuit 5 forms color-difference signals (R-Y L ) and (B-Y L ) by using the above-described signals R' and B' and the low band luminance signal Y L , and supplies those to the above-described encoder 6 and the above-described automatic white balance adjusting circuit 26.
In such a manner, the color-difference signals of which the white balance has properly been adjusted mainly by the tracking correction circuit 29 in a case where the illumination light approximately comes under Planck's radiation law, or by the work of the tracking correction circuit 29 and the comparison amplifier 22 in a case where the illumination light does not approximately come under Planck's radiation law, can be supplied to the encoder 6. Also, in this embodiment, the width of the output signal from the averaging circuit 28 may be made narrowed to such an extent that when, for example, the fluorescent lamp (white color) issues the illumination light, the white balance is adjusted just correctly, so that an automatic white balance adjusting device which is not very susceptible to the influence of the leaves of trees in the picture can be realized.
Also, though, in each of the above-described embodiments, the arrangement that the white balance is adjusted by controlling the gains for the R signal and B signal has been shown, even these embodiments are easily applicable to other publicly known arrangements, for example, the one in which the white balance is adjusted by adding or subtracting the low band luminance signal to or from the color-difference signals (R-Y L ) and (B-Y L ).
|
An automatic white balance adjusting device in which white balance adjustment is performed by feedback controlling gains for color signals obtained from an image pickup element, comprising a first computing circuit for computing the color signals, a circuit for producing control signals for controlling the gains of the color signals on the basis of a signal output from the first computing circuit, a second computing circuit for computing the color signals in a different operation from that of the first computing circuit, and a circuit for correcting the control signals on the basis of a signal output from the second computing circuit.
| 7
|
RELATED APPLICATIONS
This application claims priority to U.S. application Ser. No. 14/102,731, filed Dec. 11, 2013, which in turn claims priority to U.S. Provisional No. 61/765,387, filed Feb. 5, 2013.
BACKGROUND
Expanded polystyrene (EPS) is a rigid and tough, closed-cell foam. It is usually white and made of pre-expanded polystyrene beads. EPS is used for disposable trays, plates, bowls and cups; and for carry-out food packaging and refrigerant containers, as it has good insulating properties. Other uses include molded sheets for building insulation and roofing materials, and packing material (“peanuts”) for cushioning fragile items inside boxes. Sheets are commonly packaged as rigid panels (generally sized as 4 by 8 or 2 by 8 feet in the United States), which are also known as “bead-boards.”
There are two basic processes of polymerizing EPS. Suspension polymerization involves use of a blowing agent (typically pentane) which is used to generate the cells which enhance the insulating properties. But pentane is undesirable for the environment, because, like other organic solvents, exposure to it is associated with toxicity to the nervous system, reproductive damage, liver and kidney damage, respiratory impairment, cancer, and dermatitis.
A polymerization process which reduces the amount of pentane required to generate a product with desired insulating properties is desirable to reduce the exposure of workers to it, and to reduce the release of pentane into the environment. Following production of EPS, it can be molded or extruded into desired shapes and forms.
SUMMARY
EPS is made in a suspension polymerization process as follows.
Styrene liquid is mixed in kettle with demineralised water, a peroxide (which is preferably dibenzoyl peroxide, hydrogen peroxide 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, or hydrogen peroxide) a nucleating agent (like a paraffin wax) and optionally, flame retardant chemicals (which are preferably brominated compounds, including decabromodiphenyl oxide, phenoxy tetrabromnobisphenol A, tetrabromobisphenol A bis (allyl ether, hexabromocyclododecane, and brominated polymer)), included if desired for the final product. D-limonene is also added to act as a plasticizer. A primary suspending agent, preferably tricalcium phosphate (TCP) in the form of fine particles, is used to control the bead size. Generally, one also uses an extender (preferably dodecylbenzenesulfonate or another persulfate salt, e.g., ammonium or potassium persulfate) to enhance the suspending agent particles suspension of the polymerizing styrene droplets in the water. Another type of soap surfactant, or a suspension agent (molecular colloids, such as polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), in combination with inorganic alkali metal salts, such as Mg 2 P 2 O 7 and Ca 3 (PO 4 ) 2 (so-called Pickering salts) or, other alkali metal salts including sulfates, chlorides, carbonates or hydrogencarbonates), can be used as the extender to activate the TCP.
Polymerization takes place in two stages, and during the first stage the mixture is heated to about 88° C. and the first free-radical polymerization initiator, for example dibenzoyl peroxide, radicalizes (or polymerizes) to bring the styrene polymerization to about 80% of completion. Thereafter, with heating to about 118° C., the second polymerization initiator already added is completing the polymerization: i.e., tert-butyl perbenzoate, tert-butyl peroxy-2-ethylhexanoate, t-butyl ethylhexylmonoperoxycarbonate or t-amyl ethylhexylmonoperoxycarbonate. Prior to the second temperature step up, the pentane (between 3 to 8% by wt) is also added as a blowing agent in the final product, to control the cell size. The nucleating agent (preferably paraffin) is used to help control cell structure, i.e., uniformity and size. The cell sizes and uniformity control the insulation properties of the final product.
It was found that using D-limonene as the plasticizer during the first stage of polymerization allowed use of less pentane, to produce beads with cells of the same size as when no limonene but more pentane is used.
To form commercially useful products, the beads of polystyrene are heated to melt them, preferably with steam. This allows release of the blowing agent and beads expand as a result. The expanded beads can then be placed into a mold, and the heating step can be repeated to fuse the beads inside the mold. These last two steps can be performed by the customer, who can use their own molds to form articles they desire from the beads. Customers can specify bead sizes and cell sizes (thermal resistance) in the beads they order. Larger bead sizes are preferred for use in molds to produce larger panels and objects (e.g., pre-fabricated walls for the construction industry). Smaller bead sizes can be formed into insulating panels for portable insulating products (coolers) or roofing tiles.
In an extrusion process for EPS, described below, it is also possible to substitute the more environmentally-compatible limonene for hydorfluorocarbons or carbon dioxide.
DETAILED DESCRIPTION
Following making the beads generated by the processes in the summary, they are formed into boards, blocks or sheets or other forms for commercial use. The party making formed products may be different from the party making the beads. That is, contractors purchase beads with desired properties to form into desired products, with desired properties.
A preferred method of forming desired product shapes is with molding. A mold serves to shape and retain the pre-foam, and steam is used to promote expansion. During molding, the steam causes fusion of each bead to its neighbours, thus forming a homogeneous product.
The product may be further shaped after molding, following a short cooling period. The molded block is removed from the mold, and may be cut or shaped as required using hot wire elements, blades, saws or other techniques.
After molding and shaping, the finished product can be laminated with other materials to give it desired characteristics, including foils, plastics, roofing felt, fibreboard or other facings such as roof or wall cladding material.
In one commercial use, sheets are formed and used in pre-manufactured insulation walls. One type of insulation wall has sheets which hook together (using a transverse insert between the sheets, or using studs running along one dimension between the sheets) to form two sheets in parallel. The sheets can be pre-formed and taken to the site, after which cement can be poured into the space between the sheets, to form a cement wall with enhanced insulation properties.
In other commercial uses, beads with high thermal resistance (formed as described above in Example I) are used to form the walls of a cooler (refrigerant container). The light weight and good insulating properties of EPS make it well suited for use in containing refrigerant and blood, tissues or other biological products.
Use of D-limonene allows control of the cell size in the beads with less pentane, allowing beads to be formed having desirable properties for any of a number of commercial uses. The bead sizes and cell sizes can be controlled in a manner well known to those skilled in the art using the processes described herein.
D-limonene could also be used in forming expanded polystyrene in an extrusion process. Polystyrene granules would be melted in an extruder and D-limonene (the blowing agent), or a mixture of D-limonene with another blowing agent such as CO2 or hydrofluorocarbons, would be injected into the extruder under high pressure where it would dissolve into the polystyrene melt. In the first case, use of CO2 and/or hydrofluorocarbons is eliminated, and in the second case the the amount thereof is reduced, in each case, by the substitution of D-limonene for CO 2 and/or hydrofluorocarbons. The blowing-agent containing melt then exits the extruder via a round die. The round die contains multiple holes, and the polymer emerges through the holes in the die into cooling water under pressure, and the polymer is then cut in pellets. As the cut pellets are cooled, the dewatering and screening process for suitable pellets is initiated, in the same way as in a normal suspension reactor system.
EXAMPLE I
Using the following ingredients in the following amounts and following the procedure outlined above, we generated beads with the following sizes and properties.
1 litre of demineralized water and 1 liter of styrene 3.5 grams of dibenzoyl peroxide 0.5 grams of paraffin 6.5 grams of a flame retardant 2.0 grams of limonene 2.0 grams of TCP 0.01 grams of dodecylbenzenesulfonate 1.5 grams of second initiator (tert-butyl perbenzoate) 50 grams of pentane
The temperature of the first polymerization was 88° C. and the second polymerization was at 118° C.
This formulation generated beads of 1.0 mm diameter, on average, with an average cell size of about 60-70 microns. Compared to a similar process without limonene, the cell size would be about 30-50 microns with the other ingredients and steps held the same as in Example I. One would need to increase pentane by about 25% by weight to get beads with similar cell sizes (60-70 microns), if D-limonene was not used as the plasticizer. These beads have insulating properties to make them suitable for use in as insulating materials in construction, for refrigeration and shipping containers, and for other applications.
EXAMPLE II
Using the following ingredients in the following amounts and following the procedure outlined above, EPS beads were generated.
1 liter of deminerlized water and 1 liter of styrene 3.5 grams of dibenzoyl peroxide 0.5 grams of paraffin 1.0 grams of limonene 2.0 grams of TCP 0.01 grams of dodecylbenzenesulfonate 1.5 grams of second initiator (tert-butyl perbenzoate) 50 grams of pentane
EXAMPLE III
Using the following ingredients in the following amounts and following the procedure outlined above, EPS beads were generated.
1 liter of deminerlized water and 1 liter of styrene 3.5 grams of dibenzoyl peroxide 1.0 grams of paraffin 1.0 grams of limonene 2.0 grams of TCP 0.01 grams of dodecylbenzenesulfonate 1.5 grams of second initiator (tert-butyl perbenzoate) 50 grams of pentane
The specific methods, processes and compositions described herein are representative of preferred embodiments and are exemplary and not intended as limitations on the scope of the invention. Other objects, aspects, and embodiments will occur to those skilled in the art upon consideration of this specification, and are encompassed within the spirit of the invention as defined by the scope of the claims. It will be readily apparent to one skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention. The invention illustratively described herein suitably may be practiced in the absence of any element or elements, or limitation or limitations, which is not specifically disclosed herein as essential. Thus, for example, in each instance herein, in embodiments or examples of the present invention, any of the terms “comprising”, “including”, containing”, etc. are to be read expansively and without limitation. The methods and processes illustratively described herein suitably may be practiced in differing orders of steps, and that they are not necessarily restricted to the orders of steps indicated herein or in the claims. It is also noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural reference, and the plural include singular forms, unless the context clearly dictates otherwise. Under no circumstances may the patent be interpreted to be limited to the specific examples or embodiments or methods specifically disclosed herein. Under no circumstances may the patent be interpreted to be limited by any statement made by any Examiner or any other official or employee of the Patent and Trademark Office unless such statement is specifically and without qualification or reservation expressly adopted in a responsive writing by Applicants.
The invention has been described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention.
The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intent in the use of such terms and expressions to exclude any equivalent of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention as claimed. Thus, it will be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.
|
Disclosed is a process for production of expanded polystyrene using D-limonene as a plasticizer, which allows reducing the amount of pentane in the process, yet allows generating beads with similar cell size as if greater quantities of pentane had been used. Pentane is an organic solvent with toxicity associated with organic solvents. After forming beads, they are melted in a mold to form a variety of products, or they can be extruded in a process where limonene is used instead of or in addition to other blowing agents.
| 2
|
FIELD OF THE INVENTION
The present invention relates generally to containers for electronic components, more particularly, to containers for protecting such electronic components from electrostatic discharges and from the fields that emanate from electrostatic charges.
BACKGROUND OF THE INVENTION
When two surfaces are brought in contact with each other, a transfer of electrons may occur resulting in a residual static electrical charge when the surfaces are separated. This phenomena is known as triboelectricity or generally as static electricity. As surfaces move in contact past each other, significant electrostatic charges can be built up on the surfaces, thereby creating strong electric fields.
One of the problems associated with sensitive electronic components is that the fields or discharge of even a relatively small electrostatic charge in close proximity to the component can damage the component. For example, an electrostatic charge on a surface of the electronic component or on the surface of a user can be discharged when that user comes into contact with the device. Such a discharge can destroy the sensitive circuitry internal to the device.
To provide protection from electrostatic discharge, it is well known in the art to place sensitive electronic components into anti-static packaging that employs the Faraday cage effect. The Faraday cage effect relies on the fact that electricity generally does not penetrate a conductive enclosure, but rather the electrical discharge will go around the enclosed space, perhaps on the surface of the enclosure, seeking the path of least electrical resistance en route to the lower potential it is pursuing.
A Faraday cage is recognized in the art as a substantially enclosed, at least partially conductive, structure. By substantially surrounding a static sensitive device with an electrically conductive or electrostaticly dissipative enclosure, the device is shielded from damaging electrostatic charges originating outside of the enclosure. Electrostatic dissipative materials have been generally defined as having a surface resistivity of between 10 5 and 10 12 ohms/square.
However, such anti-static packaging must respond to other variables in the environment in which it is actually used. For example, the electronic component is typically inserted inside the packaging and later removed from the packaging for use. Both insertion and removal of the electronic component provide an opportunity for a electrostatic discharge, especially if a human operator is involved. Thus it is important to reduce the risk of damage by electrostatic charges when the component is inserted into an anti-static package and again when that user or another user removes the electronic component from the anti-static package. By keeping the component away from direct contact with any user inserting or removing the device from the anti-static package, the opportunity for a destructive electrical discharge via the user is reduced. A variety of methods have been employed to reduce the risk of damage by electrostatic charges when a user is manipulating an electronic component, but these typically require the user to use other devices or tools other than the package itself to manipulate the object. It would be advantageous to provide a mechanism to allow the user manipulating the electrical component to use the anti-static package itself to reduce the risk of damage by electrostatic charges. It would alto be desirable to do so without creating any significant additional electrostatic charges. Furthermore, the package should be easier to manipulate than existing packages with anti-static features.
Another problem encountered in packaging electronic components is that many such components include leads extending beyond the surface of the component. Particularly in surface-mount technology, chip leads are often so small and closely spaced together that even a relatively minor contact between the leads and other objects can deform the chip leads, necessitating difficult repair efforts or scrapping of an otherwise operational device. It would be advantageous to provide an anti-static package wherein the possibility of deforming such leads is minimized during shipping and handling.
Another difficulty to be overcome is that such an anti-static package should be able to accept electronic devices of a range of sizes and not just one specific size. Such a feature would simplify the process of packaging electronic components by decreasing the number of different anti-static packages required to accommodate a variety of products in the allowed size range. At the same time the anti-static package must itself be readily capable of being packaged, in some instances, for further anti-static protection.
SUMMARY OF THE INVENTION
It is a primary object of this invention to provide an improved anti-static package which permits a user to manipulate electronic components sensitive to electrostatic charges and discharge without any damage to the components from electrostatic charges.
It is a further object of the invention to provide improved protection against electrostatic discharges through a user inserting or removing sensitive electronic components from the package.
It is a still further object of the invention to use the anti-static package itself to allow a user to physically manipulate an electronic component while reducing the risk of damage by electrostatic charges.
It is yet another object of the invention to use the anti-static package itself to ease its opening and closing.
Another object of the invention is to provide an improved anti-static package whose manipulation of the electronic component does not create a significant amount of residue on the surface of the electronic component.
Still another object of the invention is to provide an improved anti-static package that does not itself create a significant amount of electrostatic charges when manipulating the electronic component.
A further object of this invention is to provide an improved anti-static package in which leads on the electronic component are inhibited from making direct contact with a surface of the package.
Still another object of this invention is to provide an improved anti-static package capable of holding an electronic component selected from a range of sizes and shapes.
Yet another object of this invention is to provide an improved anti-static package that itself can be readily contained within another anti-static container.
Other objects and advantages of the invention will be apparent from the following detailed description and the accompanying drawings.
In accordance with the present invention, the foregoing objectives are realized by providing an anti-static package for protecting sensitive electronic components from electrostatic charges, the anti-static package being thermoformed from an electrostatic dissipative plastic into a container body and a lid adapted to the container body. The bottom of the container body has a raised pedestal formed in the center for elevating and holding an enclosed electronic component's leads away from the surrounding portion of the bottom. A rectangular shaped compressible member made of a resilient foamed plastic is attached to the inside surface of the lid above the pedestal in order to secure the electronic component between the pedestal and the compressible member for shipping. The compressible member has a specially selected anti-static adhesive attached to its lower side for forming a releasable adhesive bond with the electronic component. When the electronic component is adhesively bonded to the lid through the compressible member, the user can lift the electronic component with the lid in order to relocate it to any desired location. The lid has two depressions formed in its outside surface which are adapted to receive the user's fingers. The two finger depressions form corresponding camming surfaces on the inner side of the lid which are positioned on either side of the compressible member. When the user inserts their fingers into the finger depressions and squeezes the lid, the lid easily becomes deformed which in turn eases separation of the lid from the container body. After the user has relocated the electronic component attached to the lid to a desired location, the user increases the force used to squeeze the lid, causing the two camming surfaces to contact the attached electronic component and forcibly break the releasable adhesive bond by pushing the electronic component away from the lid, thereby severing the electronic component from the lid. The releasable adhesive was specially selected for its anti-static properties and the substantial lack of adhesive residue left on the electronic component after the adhesive bond is broken.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an anti-static package according to a preferred embodiment of the present invention;
FIG. 2 is a side view of a user's hand positioning a lid of an anti-static package according to a preferred embodiment of the present invention above an electronic component.
FIG. 3 is a side view of a user's hand positioning a lid of an anti-static package according to a preferred embodiment of the present invention, with the electronic component attached to the lid, above the container body.
FIG. 4 is a side view of a user's hand squeezing a compressible member and deforming the shape of the lid.
FIG. 5 is a plan view of the top of the lid of an anti-static package according to a preferred embodiment of the present invention.
FIG. 6 is plan view of the side of the lid of an anti-static package according to a preferred embodiment of the present invention.
FIG. 7 is plan view of the bottom of the lid of an anti-static package according to a preferred embodiment of the present invention.
FIG. 8 is a plan view of the top of the container body of an anti-static package according to a preferred embodiment of the present invention.
FIG. 9 is plan view of the side of the container body of an anti-static package according to a preferred embodiment of the present invention.
FIG. 10 is a perspective view of an anti-static box container for enclosing an anti-static package according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the invention is susceptible to various modifications and alternative forms, a specific embodiment thereof has been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed. On the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
Turning now to the drawings and referring first to FIG. 1, there is shown an improved anti-static package 10 made of electrostatic dissipative thermoformed plastic. Thermoformed plastic was chosen because it permits relatively easy and inexpensive fabrication of the anti-static package 10 which has multi-faceted surfaces. The anti-static package 10 is electostaticly dissipative in order to prevent the accumulation of electrostatic charges on the package to protect the contents of the package from electrostatic discharges. Although the anti-static package 10 may be fabricated as a unitary plastic body, in the preferred embodiment PENTASTAT™ SC 660/05 Vinyl Rigid Film sold by Klockner Pentaplast of America, Inc. of Gordonsville, Va. is used to fabricate a container body 12 and a lid 14 adapted to the container body 12 which together make up the anti-static package 10. The container body 12 has four sides 16 with rounded comers, and an annular bottom 18. As illustrated in FIGS. 1, 8 and 9, the annular bottom 18 is formed around a raised pedestal 20 for elevating and holding the leads of an enclosed electronic component (not shown in FIG. 1, refer to 22 in FIGS. 2, 3 and 4) away from the annular bottom 18. The raised pedestal 20 helps to isolate the leads of the electronic component 22, thus preventing damage to the leads from direct contact with the anti-static package 10 itself.
The lid 14 has a central containment area 24 formed on the inner lid surface to partially enclose a compressible member 26. The central containment area 24 is centrally located on the lid 14 above the raised pedestal 20 when the anti-static package 10 is closed, and has opposing walls between which the compressible member 26 resides. The central containment area 24 functions to provide a place to attach, contain and compress the resilient compressible member 26.
In the preferred embodiment the compressible member 26 is rectangular in shape and made of a resilient foamed plastic. The compressible member 26 is attached within the central containment area 24 by an adhesive (not shown), and is thereby positioned above the raised pedestal 20 when the anti-static package 10 is closed.
The container body 12 and the lid 14 have corresponding mating ridges, a lid mating ridge 28 on the lid 14 and a container mating ridge 30 on the container body 12, that permit the container body 12 and the lid 14 to engage each other to become attached. The outside diameter of the vertical wall of the ridge 28 on the lid 14 is selected to match the inside diameter of the vertical wall of the ridge 30 on the container body 12 so the lid 14 can be attached to the container body 12 in a snug fit. When the mating ridges 28,30 are engaged, the anti-static package 10 is closed and some force is required to open it. The lid mating ridge 28 is formed in the lid 14 by the outer perimeters of a first shallow depression 32a and a second shallow depression 32b on opposite sides of the central containment area 24.
The opposed walls of the central containment area 24 are partially encompassed by a cavity 34. In a preferred embodiment the cavity 34 is made up of a first finger depression 36a and a second finger depression 36b in the lid's 14 outer surface. The two finger depressions 36a,36b are formed within the two shallow depressions 32a,32b. The two finger depressions 36a,36b are each adapted to receive at least one finger. The central containment area 24 is bounded on opposite sides by the two finger depressions 36a,36b to allow the compressible member 26 within the central containment area 24 to be compressed when the user's fingers in the two finger depressions 36a,36b are moved toward each other in a squeezing motion. Note that for purposes of this specification the thumb is considered to be a finger. The bottoms of the depressions 36a and 36b form first and second camming surfaces 38a and 38b on opposite sides of the compressible member 26.
As shown in FIG. 2, the compressible member 26 has a device-holding side 40 that faces away from the lid 14. As seen in FIGS. 2 and 6, the compressible member 26 extends below the plane of the two camming surfaces 38a,38b, thereby holding the device-holding side 40 below the two camming surfaces 38a,38b. As illustrated in FIGS. 2, 3, 4, 6, and 7, an adhesive 42 is attached to the device-holding side 40. In a preferred embodiment, the film side of 3M SCOTCH™ 40 Anti-Static Utility Tape, sold by 3M, is attached to the device-holding side 40 with a double-sided adhesive tape, thereby leaving the adhesive side of the anti-static tape exposed and facing away from the lid 14.
As seen in FIG.2, the user has positioned the compressible member 26 above the electronic component 22. The device-holding side 40 is extended below the plane of the two camming surfaces 38a,38b to enable the user to first bring the adhesive 42 into contact with the electronic component 22. As the user continues to bring the lid 14 closer to the electronic component 22, the compressible member 26 is compressed. Pressure created between the now compressed compressible member 26 and the electronic component 22 serves to strengthen an adhesive bond between the adhesive 42 and the electronic component 22.
FIG. 2 illustrates how the lid 14 is adapted to be held by the user's hand. Typically, the user places a thumb and at least one other finger in the two finger depressions 36a,36b, with at least one finger per depression, in order to hold and manipulate the lid 14. The lid 14 enables the user to relocate an adhesively bonded electronic component 22 as desired by the user and reduces the risk of damage from electrostatic charges. FIG. 2 illustrates the user's hand positioning the lid 14 just above an electronic component 22. The user lowers the lid 14 to bring the adhesive 42 on the device-holding side 40 into contact with the electronic component 22 as described above. The user preferably continues to bring the lid 14 closer to the electronic component 22 until the two camming surfaces 38a,38b contact the surface of the electronic component 22, although this is not essential to form an adequate adhesive bond. Because the plastic forming the two camming surfaces 38a,38b requires substantially more force to deform than is required to compress the compressible member 26, the user knows he or she can stop pushing the lid closer to the electronic component 22 when the two camming surfaces 38a,38b contact the electronic component 22. This signals to the user that an adhesive connection has been formed between the electronic component 22 and the lid 14. At this point, if the lid 14 and electronic component 22 are otherwise free to be moved, the user lifts the electronic component 22 and relocates it as desired, without directly touching the electronic component 22, because it is attached to the other side of the lid 14. Because the lid 14 is between the operator's hand and the electronic component 22 the risk of damage to the electronic component 22 from electrostatic charges is greatly reduced.
Once the electronic component 22 is attached to the lid 14 as described above, the electronic component 22 may be positioned above the raised pedestal 20 in the container body 12. In FIG. 3 the user has positioned the electronic component 22 just above the raised pedestal 20. To fully close the anti-static package 10 the user must align the lid mating ridge 28 with the container mating ridge 30, and then lower the lid 14 to engage the mating ridges 28,30 (FIG. 3). The anti-static package 10 is designed such that when the mating ridges 28,30 are fully engaged to close the anti-static package 10, the electronic component 22 is resting on the raised pedestal 20.
The user can easily open the anti-static container 10 by gently squeezing the lid 14 until the lid 14 bends to separate it from the body 12 and then lifting the lid 14 off the container body 12. FIG. 4 illustrates a user squeezing the central containment area 24 of the lid 14. As shown in FIG. 4 the user has inserted two fingers, one in each of the two finger depressions 36a,36b, and is compressing the central containment area 24. The user squeezes the first and second finger depression 36a and 36b together such that the lid 14 deforms as shown, causing the camming surfaces 38a and 38b to contact the electronic component 22. At this point the lid 14 is easily removable from the container body 12, but the electronic component 22 is still attached by the adhesive 32 to the lid 14. As illustrated in FIG. 4, the lid 14 is designed so that it can bend along an axis in the plane of the lid 14 and generally running between the two shallow depressions 32a,32b and the two finger depressions 36a,36b. The exact location of the axis of bending is not critical.
The symmetry of the two finger depressions 36a,36b can be clearly seen (FIG. 5). The two finger depressions 36a,36b form a pair of side lobes 44 and 46 which help adapt the lid 14 to manipulation by the user's fingers by providing a surface area more closely conforming to the user's fingers to give the user greater leverage when squeezing the lid 14.
To further reduce the risk of damage to the electronic component 22 from electrostatic charges, it is preferred to enclose the anti-static package 10 inside an anti-static box container 50 such as a corrugated fiberboard container shown in FIG. 10 and described in more detail in U.S. Pat. No. 5,107,989, incorporated herein by reference.
FIG. 10 illustrates the anti-static box container 50 as a paperboard or paper box having an electrically conductive coating on its exterior surface, and a coating of electrostatic dissipative material its interior surface. The electrically conductive coating preferably has an electrical surface resistivity of less than about 10 5 ohms/square, and the inorganic, non-carbonaceous, electrostatic dissipative coating has an electrical surface resistivity of greater than about 10 5 ohms/square. The electrostatic shielding material is preferably a carbonaceous material, and the electrostatic dissipative material preferably comprises particles of amorphous silica or silica-containing material coated with antimony-doped tin oxide. The surface resistivity of the carbonaceous coating is preferably in the range of from about 10 2 to about 10 4 ohms/square so that it forms an effective electrostatic shield and also quickly dissipates any charge that forms on, or comes into contact with, the coated surface. If desired, the conductive coating may be over-coated with a protective sealant, which is usually transparent.
The anti-static box container 50 includes a bottom panel 52, front and rear walls 54 and 56, a pair of end walls 58 and 60 and a lid 70. Each of the end walls 58 and 60 are formed from two panels of the paperboard blank, with the lower edge of the inside panel of each end wall forming a depending tab 58a or 60a which fits into a corresponding aperture in the bottom panel 52 so as to lock the end walls in place. The two panels of each end wall 58 and 60 form an interior cavity which receives end tabs from both the front wall 54 and the rear wall 56; and these end tabs are locked in place within the end wall after the depending tabs 58a and 60a on the inside panels of the end walls 58 and 60 have been inserted into the corresponding apertures in the bottom panel 52.
It is within the scope of this invention to vary the form factor of the anti-static box container 50 to allow enclosure of various sized anti-static packages to accommodate a range of sizes or multiple electronic components 22.
|
An anti-static package for containing and manipulating an electronic component susceptible to damage from electrostatic charges. The anti-static package is comprised of a container body and a lid, wherein the lid is adapted to allow indirect manipulation of the electronic component through the use of an adhesive surface on a compressible member attached to the lid to form an adhesive bond between the lid and the electronic component, and two camming surfaces, controlled by a user's fingers or an analogous tool The adhesive is specially selected for both its anti-static properties and the lack of residue left on the electronic component as a result of forming an adhesive bond.
| 7
|
FIELD OF THE INVENTION
This invention relates to an assembly adapted for use with a rigid member to give way in response to a contact against the rigid member and, more specifically, to an assembly incorporated into a vehicle barrier gate arm that is designed to preferentially break away when the gate arm is struck by a passing vehicle, that can be adapted to activate an alarm when broken, and that is designed to be repaired in an easy and time efficient manner.
BACKGROUND OF THE INVENTION
The use of vehicle barrier devices having a gate arm to control the passage of vehicles thereby is well known and is used in such applications as parking lots and garages, gated communities, highway toll plazas and the like. A typical vehicle barrier device is one having a gate arm that is mechanically operated, either automatically or by an attendant, to permit the passage of a vehicle thereby by raising the gate arm from a horizontal position across the front of the vehicle to a vertical position out of the path of the vehicle. The gate arm itself is typically made from a suitable rigid structural material such as wood and the like. Wooden gate arms are traditionally preferred because of their relatively low cost.
It is not uncommon for the gate arm of such device to be broken by contact with a vehicle, that has passed by the device when the gate arm was in a lowered position. When this occurs, the device must be repaired in order to continue serving as a vehicle barrier. The repair operation usually consists of replacing the gate arm with a new gate arm, however, can consist of bracing the broken portion of the existing gate aim. In either case, the repair requires that either a new gate arm be available to replace the broken gate arm, or that materials be readily available to brace the existing broken gate arm.
In most cases, the device operator does not have a replacement new gate arm or adequate repair materials in their immediate inventory due to the cost associated with such an undertaking. Therefore, the operator must order the replacement gate arm from the device manufacture, which can take weeks depending on its inventory and geographical location. During this period of time the device is unable to serve as a vehicle barrier, thereby allowing vehicle to pass freely through the otherwise controlled area. This can present both a security risk, in those applications where the device functions to permit the passage of only authorized vehicles into an otherwise secure area such as a gated community, and result in a loss of revenue, in those applications where the device functions to permit the passage of vehicles after a parking fee or toll is collected such as a parking lot or garage, or a highway toll booth.
Once the replacement gate arm is obtained, the replacement or repair operation is often time consuming and can require the assistance of more than one person. The replacement or repair operation also requires that the device be taken out of service and usually that the vehicle path by the device be blocked for some period of time during the operation.
It is, therefore, desirable that a device be constructed that is adapted for use with a vehicle barrier device to spare a gate arm of the device from serious damage when contacted by a passing vehicle. It is desired that the device be constructed in a manner that facilitates an easy and rapid repair after a gate arm has been struck and rendered inoperable by a passing vehicle. It is also desirable that the device be constructed so that any replacement part be both small in size, to facilitate easy and space efficient storage, and enable the repair operation to be carried out by one person by hand and without the need for tools.
SUMMARY OF THE INVENTION
A breakaway assembly, prepared according to principles of the invention, is adapted for use with a vehicle barrier device having a gate arm. The breakaway assembly comprises a first assembly member that is adapted to be connected at one of its ends with a movable member of a vehicle barrier device, and a second assembly member that is adapted to be connected at one of its ends with a gate arm of the vehicle barrier device. A breakable member is releasibly connected at one of its ends to the first assembly member, and is releasibly connected at an opposite one of its ends to the second assembly member. The breakable member is constructed so that it preferentially breaks between the first and second assembly members in response to a determined impact force imposed on the gate arm to spare the gate arm and gate controller from serious damage.
The breakaway assembly of this invention is designed to be easily repaired once the breakable member is broken, without the need for any tools or without the need for assistance by another, and is designed to enable a rapid repair, avoiding the need to render the vehicle barrier device inoperable for any significant amount of time. Further, the design of using a sacrificial breakable member makes storage of the necessary replacement part easy and space efficient, and reduces the cost associated with maintaining a sufficient inventory of replacement parts.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will be more fully understood when considered with respect to the following detailed description, appended claims, and accompanying drawings, wherein:
FIG. 1 is a perspective view of a vehicle control device comprising a gate arm having a breakaway assembly constructed in accordance with the practice of the present invention installed therein;
FIG. 2 is a perspective view of the breakaway assembly in FIG. 1 constructed in accordance with the practice of the present invention;
FIG. 3 is a perspective view of a breakable member for use with the breakaway assembly of FIG. 1; and
FIG. 4 is a bottom elevation view of the breakaway assembly of FIG. 2.
DETAILED DESCRIPTION
A breakaway assembly, constructed according to principles of this invention, is adapted for connection within a vehicle barrier device having a gate arm and includes a removable breakable member that is interposed between connected gate arm portions, and that is adapted to be preferentially broken when a sufficient impact force is imposed on the gate arm. Constructed in this manner, the breakaway assembly is designed to be broken upon sufficient impact force imposed on the gate arm, thereby saving the gate arm from serious damage. Additionally, the breakaway assembly is designed so that the breakable member can be easily and rapidly replaced, thereby minimizing operational downtime of the vehicle barrier device.
FIG. 1 illustrates a vehicle barrier device 10 that includes a breakaway assembly 12 of this invention. The vehicle barrier device 10 includes an operating mechanism or controller housing 14 and a movable gate arm attachment means 16 extending from the housing 14. The operating mechanism for the device 10 can be of conventional gear or belt-driven design that is adapted to cause the attachment means 16 to rotate in a clockwise direction to raise the gate arm, or a counter-clockwise direction to lower the gate arm, by electric motor operation that is either automatically actuated or actuated by operator input. Alternatively, the operating mechanism for the device 10 can be one that is operated manually, i.e., without the use of an electric motor and the like, by action of the operator.
The breakaway assembly 12 is connected to the gate arm attachment means 16 at one of its ends, and is attached to a gate arm 18 at an opposite one of its ends. It is desired that the breakaway assembly 12 be connected to the vehicle barrier device 10 at a position that is close to the attachment means 16 so that a sufficient force will be imposed on the breakaway assembly 12 to cause it to break away when the gate arm is impacted by a passing vehicle, thereby saving the gate arm itself from serious damage.
FIG. 2, illustrates an example embodiment of the breakaway assembly 12 removed from the vehicle barrier device and gate arm. The assembly 12 comprises a first member 20 having a first end 22 that is adapted for attachment to an arm base 24. The first member 20 has a rectangular geometric shape that is selected to complement the structure of the gate arm and arm base 24. The first member 20 is formed from a structurally rigid material that is suitable for withstanding a load imposed by a gate arm. Suitable materials for forming the first assembly member include metals and metal alloys. A preferred material is aluminum due to its desirable combination of structural rigidity and strength and light weight.
Moving from left to right in FIG. 2 from the first end 22, the first member 20 includes a cut out portion 26 that extends a distance there along and includes a shoulder 28 at a transition point from the cut out portion 26 to the remaining portion of the first member. The cut out portion 26 is designed to accommodate placement of the arm base 24 therein. It is desired that the arm base 24 include a complementary cut out portion 30 and shoulder 32 to ensure that the arm base fits securely against the first member first end 22, and to ensure that profile of the arm base complement and blend with the first member.
The arm base 24 is secured to the first member by conventional means, such as by nut and bolt attachment 34. The arm base 24 can be fabricated by any conventional material that is suitable for providing a secure attachment with the gate arm attachment means of the vehicle barrier device (see FIG. 1). In an example embodiment, the arm base 24 is formed from a polymer material such as polypropylene to facilitate attachment to the gate arm attachment means by clamp attachment.
The first assembly member 20 has a second end 36 that includes means for accommodating a breakable member 38 therein. In an example embodiment, the second end 36 includes a slot 40 that extends a distance towards the first end 22. The slot 40 has a depth and width sized to accommodate placement of a portion of the breakable member 38 therein. It is to be understood that the use of the slot is but one method of accommodating placement of the breakable member 38 within the first assembly member 20, and that other methods can be used and are intended to be within the scope of this invention. For example, the first assembly member 20 can be configured having another cutout portion located at the second end 36. In such embodiment, the breakable member 38 could be interposed between the new cutout portion and a plate positioned at an opposite surface of the breakable member.
In an example embodiment, for use in a particular application, the first assembly member 20 is approximately 10 centimeters long, approximately 8 centimeters wide, has cut out portion 30 that is approximately 5 centimeters long, and has a shoulder 28 that is approximately 11/2 inches thick. The first assembly member has a slot 40 that is approximately 4 centimeters deep and that is approximately 7 millimeters thick.
The first assembly member 20 includes means for releasibly locking the breakable member 38 within the slot 40. In an example embodiment, such means is in the form of holes 42 that extend through the first assembly member 20 and slot 40, and pins 44 that are disposed through the holes 42. In a preferred embodiment, the first assembly member 20 includes a pair of holes 42 that are positioned vertically (with reference to FIG. 2) relative to one another, and a pair of clevis pins 44 disposed therethrough. The clevis pins 44 are used to facilitate releasible locking attachment with the first assembly member without the need to use tools. However, conventional attachment means, such as the use of nut and bolt, can alternatively be used.
As best illustrated in FIG. 3, the breakable member 38 is generally in the shape of a rectangle, having holes 45 disposed therein to accommodate placement of the clevis pins 44 therethrough. It is desired that the breakable member be formed from a material that is both capable of supporting the weight load of the gate arm without breaking, but breaking when exposed to a sufficient horizontal force imposed by a vehicle impacting the gate arm. Suitable materials used for forming the breakable member include wood, plastic, and composites such as fiber-reinforced resin materials. In an example embodiment, the breakable member 38 is formed from fiberglass-reinforced composite. Ultimately, the type of material selected will depend on the particular application and such factors as gate arm length, gate arm weight, gate arm size, and wind effects. Typically, it is necessary to use a stronger material for forming the breakable member when the application includes a long gate arm and/or is subject to high wind effects. In an example embodiment, for use in a particular application, the breakable member 38 is approximately 9 centimeters long, 8 centimeters wide, and 6 millimeters thick.
Referring back to FIG. 2, if desired, the first assembly member 20 can include means for securing the breakable member 38 within the slot 40 that is independent of the releasibly locking means, e.g., the use of the holes and clevis pins. In an example embodiment, the first assembly member 20 includes a threaded hole 46 though one wall of the slot 40 to accommodate a set screw 48 therein. The set screw 48 is turned within the threaded hole 46 to engage an adjacent surface of the breakable member 38 within the slot 40 and thereby secure the breakable member therein to minimize or eliminate lateral space between the slot and breakable member. It is desired that such lateral space be minimized or eliminated to prevent the breakable member from wobbling within the slot due to wind effects or the like, which could cause the breakable member to crack or break prematurely.
The breakaway assembly 12 includes a second assembly member 50 that is configured identical to the first breakaway assembly member 20. Accordingly, FIG. 2 illustrates the second assembly member 50 as comprising elements having the same element reference numbers. However, the second assembly member first end 22, rather than being constructed to connect with the arm base 24, is constructed to be connected with a gate arm 57 (as shown in FIG. 1). The gate arm is constructed in a complementary manner to provide a secure fit with the second member 50, and is fixedly attached thereto by nut and bolt attachment. The gate arm can be formed from any conventional structurally rigid material, such as, metal, metal alloy, plastic, and composite.
The breakable member 38 is interposed within the slot 40 of the second assembly member 50 so that it extends between both first and second assembly members 20 and 50. The breakable member 38 is designed having a length that is greater than the depth of both slots, so that a portion of the breakable member remains exposed between the first and second assembly members. It is desired that a portion of the breakable member 38 remain exposed, and unsupported by either assembly member, to provide a designated area for breakage. To facilitate a controlled breakage of the breakable member at a designated portion it may be desirable to provide an indentation or stress riser running vertically across one or each opposed surface at the middle of the breakable member. A breakable member 38 constructed in this manner will provide a controlled break, when the gate arm is subjected to an impact force, along the indentation. In an example embodiment, as illustrated in FIG. 3, the breakable member has an indentation 52 running vertically across each opposite surface along the middle of the breakable member. In an example embodiment, for use in a particular application, the middle portion of the breakable member 38 is exposed between the slots of each assembly member for a length of approximately 11/2 centimeters.
The breakaway assembly 12, once installed into a gate arm in the manner described above, will brake at the breakable member 38 when the gate arm is subject to an impact of sufficient force. It is desired that the breakaway assembly function not break when the gate arm is subjected to insubstantial impacts or wind gusts. Therefore, the breakable member 38 is constructed to permit some degree of bending before reaching a designated breaking point. In an example embodiment, the brake member is tested to determine its brake rating by dropping a 12 pound weight onto the gate arm at different distances from the breakaway assembly. In an example application, it is desired that the breakable member break when a distance of 48 inches is reached. It is to be understood, however, that such break rating is for a particular application and will vary depending on the particular application variables, e.g., gate weight, gate size, gate dimensions, and wind effects. For example a higher brake rating would be desired in applications where the wind effects are high and/or the gate length is long, and a lower brake rating would be desired where the wind effects are low and/or the gate length is short.
Alternatively, more than one breakable member 38 can be installed within the gate arm. Such alternative use of the breakable member may be desirable, for example, in applications where the gate arm is long or where more than one break point is desired.
The breakaway assembly 12 may also include retaining means for keeping the first and second assembly members 20 and 50 loosely attached after the breakable member is broken. In an example embodiment, such means is in the form of a wire or cable 54 that is attached at opposite ends to a portion of respective first or second assembly members 20 or 50. The cable 54 is drawn loosely between the assembly members so as to not interfere with the break mechanism of the breakable member, yet to retain the second assembly member 50 and gate arm once the breakable member is broken. Such a retaining means is desirable to prevent the gate arm from being damaged, lost, or taken after it has been broken away.
Additionally, the breakaway assembly 12 can be designed to accommodate means for providing a signal for activating an audible or visual indication in the even that the breakable member becomes broken. For example, referring to FIG. 4, the first and second attachment members 20 and 50 can be constructed to accommodate a rigid or flexible member 56 that is connected at opposite ends to conventional attachment means 58, such as screws and the like, that are used to connected the cable 54. The member 56 can be in the form of an electric wire, circuit board, or the like that closes or opens a circuit to produce a signal, that is sent to an alarm or visual indicator, when the breakable member 12 is broken. Accordingly, the member 56 includes an electrical connection 60, extending therefrom and away from the breakaway assembly 12, that is connected to a desired indication means (not shown). As illustrated in FIG. 4, the member 56 is disposed between the first and second attachment means so that it is affected upon the breaking of the breakable member.
A key feature of the breakaway assembly of this invention is that it enables easy and rapid repair after the second assembly member 50 and gate arm have been broken away. The breakaway assembly is designed so that an operator can repair it within a matter of minutes without having to use special tools, and without the need for assistance from others. Once broken, the breakaway assembly is repaired, and the gate arm is placed back into operation, by: (1) loosening any set screws 48 in each respective first and second assembly member 20 and 50; (2) removing each of the clevis pins 44 from the holes 42 in both assembly members; (3) removing the broken breakable member 38 portions from the slots 40 of the first and second assembly members; (4) placing one end of a new unbroken breakable member 38 into the slot 40 of either the first or second assembly member; (5) installing the clevis pins 44 through the holes 42 of such elected assembly member, and through the breakable member portion 38 within the slot to releasibly lock the breakable member within the slot; (6) positioning the remaining assembly member adjacent the breakable member 38 so that the exposed end of the breakable member is placed within such remaining assembly member slot 40; (7) installing the clevis pins 44 through the holes 42 of such remaining assembly member to releasibly lock the breakable member within its slot; and (8) tightening any set screws 48 in both assembly members to secure the breakable member within each slot.
It is to be understood that the above description of a breakaway assembly of the present invention is provided for illustrative purposes, and can be embodied other than that specifically described and illustrated. Because of variations which will be apparent to those skilled in the art, the present invention is not intended to be limited to the particular embodiments described above. The scope of the invention is defined in the following claims.
|
A breakaway assembly comprises a first assembly member adapted for connection at one of its ends with a movable member of a vehicle barrier device, and a second assembly member adapted for connection at one of its ends with a gate arm of the vehicle barrier device. A breakable member is releasibly connected at one of its ends to the first assembly member, and is releasibly connected at an opposite one of its ends to the second assembly member. The breakable member is constructed so that it preferentially breaks between the first and second assembly members in response to a determined impact force imposed on the gate arm to spare the gate arm from serious damage, to ease and expedite repair operations, and to reduce the costs associated with maintaining and adequate inventory of replacement parts.
| 4
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The subject invention generally pertains to stepladders and more specifically to an extendable tool for such a ladder.
[0003] 2. Description of Related Art
[0004] There are a variety of lift platforms that can be attached to a stepladder. A drawback of many of them is that the user needs to use one hand to raise the platform and another one to lock it in place. This may be fine when the platform is lightweight and unloaded; however, a heavier platform or one carrying a load may be difficult to lift with just one hand. Moreover, if the platform needs to be raised to a significant height, the user may need to stretch in an awkward manner between the platform and the locking mechanism.
[0005] U.S. Pat. No. 3,208,555 discloses a hoisting attachment for a ladder where a user operates a crank to raise and lower the platform. With a hoist, a user could conceivably raise the platform by simply turning the crank and not bother with stretching between the platform and the crank. If the user, however, does not manually hold the platform or steady the load as it rises, there is a risk that the load may accidentally slip off the platform, which could damage the load or injure the user.
[0006] Consequently, a need exists for a ladder-mounted lift platform that overcomes the drawbacks of current lift platforms.
SUMMARY OF THE INVENTION
[0007] An object of some embodiments of the invention is to provide a ladder-mounted platform where the platform can be readily raised by simply pushing the platform up, and the platform automatically stays at the elevated position without having to manually actuate a locking mechanism.
[0008] Another object of some embodiments is to support the platform with two extendable rods for stability and strength, and position each rod sufficiently close to a locking mechanism so that each hand of the user can simultaneously release the locking mechanism and grip one of the rods so that the platform can be lowered in a controlled manner.
[0009] Another object of the invention is to enable a user to simultaneously stand upon a lower step of a stepladder (thereby adding stability to the ladder), using one hand to grasp the side of the ladder (thereby stabilizing the user), and using the other hand to simultaneously 1) raise the platform 2) steady the load on the platform, and 3) lock the platform at the desired elevation.
[0010] Another object of the invention is to install a platform just above an uppermost step a stepladder so that the platform creates an obstruction that deters a user from stepping upon that uppermost step.
[0011] Another object of some embodiments is to support a raisable platform using square or rectangular tubes (as opposed to round ones) to ensure that grippers solidly engage discrete points on a facet of the tube.
[0012] Another object of some embodiments is to provide the platform or ladder-mounted tool with a stop member that ensures at least minimum hand clearance between the platform and the top step of the ladder to avoid creating a hand-pinching hazard therebetween.
[0013] Another object of some embodiments is to provide the ladder tool with clamp assembly that includes a spring for urging the clamp to a hold-position so that the clamp assembly automatically holds the platform at a raised position upon simply releasing the platform and clamp assembly.
[0014] Another object of some embodiments is to support the platform with two extendable rods that include an evenly distributed series of gripping points so that the clamp assembly can selectively engage the points to solidly hold the platform at a series of discrete elevations.
[0015] Another object of some embodiments is to provide a plastic platform with a raised outer rim to help contain a wooden top, wherein the wooden top can be readily replaced, cut, drilled, nailed into, or otherwise modified to meet the needs of the user.
[0016] Another object of some embodiments is to support the platform with two extendable rods and use a rod-locking mechanism with a lever that can unlock the rod-locking mechanism by pushing the lever down or towards an adjacent rod so that the user can readily and simultaneously grip a rod and move the lever to its unlock position with one hand.
[0017] Another object of some embodiments is to provide a ladder-mountable lift platform with a clamping mechanism that includes a rod-gripper and an actuating lever that extend integrally from each other to comprise a unitary piece, which can reduce product cost and increase reliability.
[0018] Another object of some embodiments is to place the platform-supporting rods between the locking levers so that a user can readily grip the rods and actuate the levers at the same time.
[0019] One or more of these and/or other objects of the invention are provided by a tool or method that enables a user to raise a ladder-mounted platform and automatically lock it into position by simply releasing the platform
BRIEF DESCRIPTION OF THE DRAWING
[0020] FIG. 1 is a front view of a stepladder with a platform tool being manually raised.
[0021] FIG. 2 is a front view of the stepladder of FIG. 1 but showing the platform held at a raised position.
[0022] FIG. 3 is a front view of the stepladder of FIG. 1 but showing the platform being lowered.
[0023] FIG. 4 is a left side view of an upper portion of the stepladder of FIG. 1 .
[0024] FIG. 5 is a cross-sectional front view of a RH side of the platform tool with the clamp assembly in a hold-position.
[0025] FIG. 6 is a cross-sectional view similar to FIG. 5 but showing the platform being lifted while the clamp assembly is in a hold-position.
[0026] FIG. 7 is a cross-sectional view similar to FIGS. 5 and 6 but showing the clamp assembly in a release-position that allows the platform to be freely raised or lowered.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] FIGS. 1-7 shows a tool 10 that can be attached to an uppermost step 12 , which is above a second highest step 14 , of a self-supporting stepladder 16 . The term, “stepladder” refers to a self-standing generally triangular structure with a series of steps. Tool 10 includes a work platform 18 supported by two substantially parallel rods 20 (a RH rod 22 and a LH rod 24 ) that can be manually raised and lowered. Platform 18 can be used for holding tools, light fixtures, planks, boards, conduit, pipes, drywall, paint cans, a vise or clamp, and other parts. Tool 10 also includes a clamp assembly 26 that works in conjunction with rods 20 in such a way as to make it easy and safe to raise and lower platform 18 . Clamp assembly 26 is movable between a hold-position ( FIGS. 1, 2 , and 4 - 6 ) and a release-position ( FIGS. 3 and 7 ).
[0028] FIG. 1 shows a user 28 manually lifting platform 18 from a lowered position ( FIG. 5 ) to a raised position ( FIG. 2 ). While user 28 is lifting platform 18 , clamp assembly 26 (which comprises a RH clamp assembly 30 and a LH clamp assembly 32 ) is in the hold-position. Even with clamp assembly 26 in the hold-position, platform 18 can be readily raised without significant resistance.
[0029] FIG. 2 shows that upon manually releasing platform 18 , the platform generally stays at its raised position (or settles to a discrete point slightly below that) and does so automatically because clamp assembly 26 is in its hold-position even while platform 18 is rising. The term, “automatically” means that a clamp does not have to be manually manipulated in order for the platform to be held in place.
[0030] FIG. 3 shows how platform 18 can be lowered at a controlled rate of descent. With a right-hand 34 , user 24 simultaneously grips RH rod 22 and pushes a RH lever 36 of RH clamp assembly 30 down to an unlock-position (RH unlock position), which moves RH clamp assembly 30 to its release position (RH release position, see also FIG. 7 ). Likewise, user 28 uses a left-hand 38 , to simultaneously grip LH rod 24 and push a LH lever 40 of LH clamp assembly 32 down to an unlock-position (LH unlock position), which moves LH clamp assembly 32 to its release position (LH release position). Friction between the user's hands and rods 22 and 24 slow the decent of platform 18 .
[0031] Although such operation can be achieved by various structural designs, details of one example of the invention are shown in FIGS. 4-7 . The following description will be primarily with reference to the right-hand side of tool 10 ( FIGS. 5-7 ), since the left-hand side ( FIG. 4 ) has basically the same structure as the right side.
[0032] In this example of the invention, tool 10 comprises a base 42 that can be removably attached to uppermost step 12 by way of a fastener 44 . A ring nut 46 fastens a RH sleeve 48 to base 42 . A coupling 50 connects a tube 52 to RH sleeve 48 , and a cap 54 can be fitted to the bottom end of sleeve 52 . RH rod 22 , in this example, is square tubing that slides within the generally cylinder pieces of sleeve 48 , coupling 50 and tube 52 . A bracket 56 connects an upper end of rod 22 to the underside of platform 18 .
[0033] To hold RH rod 22 at various elevations, RH clamp assembly 30 includes a RH clamp housing 58 , a RH gripper 60 , a RH spring 62 , and RH lever 36 . RH lever 36 and RH gripper 60 can be integral extensions of each other, whereby RH lever 36 and RH gripper 60 comprise a unitary piece. A pin 64 allows RH lever 36 and RH gripper 60 to pivot relative to RH clamp housing 58 . Spring 62 urges RH lever 36 in a RH lock direction (such as upward) to the RH lock-position and urges RH gripper 60 to a RH hold-position where RH gripper 60 engages RH rod 22 ( FIGS. 5 and 6 ).
[0034] Manually pushing RH lever 36 in a RH unlock direction (such as downward) against the urging of RH spring 62 moves RH gripper 60 to the RH release position where RH gripper 60 disengages RH rod 22 as shown in FIG. 7 .
[0035] To positively hold RH rod 22 at various discrete elevations, RH rod 22 includes a series of discrete gripping points 66 that can be solidly engaged by RH gripper 60 . Gripping points 66 can be in the form of recesses or protrusions.
[0036] Cap 54 at the bottom of tube 52 provides a stop member that can limit the downward movement of tube 22 , thereby ensuring that at least a minimum hand clearance exists between the underside of platform 18 and the top surface of uppermost step 12 to avoid creating a hand-pinching hazard therebetween. It should appreciated by those of ordinary skill in the art that a various other structures could provide a functionally equivalent stop member.
[0037] It should be noted that all of the named RH elements have an equivalent LH corresponding element. For instance, RH sleeve 48 corresponds to LH sleeve 48 ′, RH rod 22 corresponds to LH rod 24 , RH gripper 60 corresponds to LH gripper 60 ′, the RH hold-position corresponds to the LH hold-position, the RH release-position corresponds to the LH release-position, the RH lock position corresponds to the LH lock position, the RH unlock-position corresponds to the LH unlock-position, the RH lock direction (e.g., upward) corresponds to the LH unlock direction (e.g., also upward), the RH unlock direction (e.g., downward) corresponds to the LH unlock direction (e.g., also downward), etc.
[0038] In some embodiments platform 18 comprises a plastic base 68 with a raised outer rim 72 and a wooden top 70 overlaying plastic base 68 , wherein the raised outer rim 72 helps align wooden top 70 to plastic base 68 . Wooden top 70 provides a convenient work surface that can be readily replaced, cut, drilled, nailed into, or otherwise modified to meet the needs of the user. Rim 72 is preferably less than 1.5-inches tall (inside vertical dimension) so that standard lumber having a 2-inch nominal thickness (1.5-inch actual thickness) can protrude above rim 72 . Platform 18 can also be provided with various openings and cavities for holding an assortment of tools and parts.
[0039] Although the invention is described with reference to a preferred embodiment, it should be appreciated by those of ordinary skill in the art that various modifications are well within the scope of the invention. Therefore, the scope of the invention is to be determined by reference to the following claims.
|
An adjustable platform for a stepladder can be raised by simply lifting the platform manually, and the platform automatically stays there after being released. For safety, strength and stability, the platform is supported by two extendable rods. Even though there are two rods and two clamps for holding them, a single worker can still release and lower the platform at a controlled rate of descent. To do this, the clamps are of a particular design and are strategically positioned relative to the rods.
| 4
|
FIELD OF THE INVENTION
[0001] The present invention is directed to a multilayer coating for hot section turbine components, and more specifically for a coating that includes rare earth elements.
BACKGROUND OF THE INVENTION
[0002] Calcium-magnesium-aluminum-silicate (CMAS) infiltration is a phenomenon that is linked to thermal barrier coating (TBC) spallation in hot section turbine components.
[0003] Thermal barrier coatings are utilized on hot section engine components including combustor section and turbine section components to protect the underlying base materials from high temperatures as a result of the flow of hot gases of combustion through the turbine. These hot gases of combustion can be above the melting point of the base materials, which typically are superalloy materials, being based on iron, nickel, cobalt and combinations thereof. Of course, the thermal barrier coatings provide passive protection from overheating, and are used in conjunction with cooling airflow that provides active cooling protection.
[0004] Under service conditions, these thermal barrier-coated hot section engine components can be susceptible to various modes of damage, including erosion, oxidation and corrosion from exposure to the gaseous products of combustion, foreign object damage and attack from environmental contaminants. The source of the environmental contaminants is ambient air, which is drawn in by the engine for cooling and for combustion. The type of environmental contaminants in ambient air will vary from location to location, but can be of a concern to aircraft as their purpose is to move from location to location. Environmental contaminants that can be present in the air include sand, dirt, volcanic ash, sulfur in the form of sulfur dioxide, fly ash, particles of cement, runway dust, and other pollutants that may be expelled into the atmosphere, such as metallic particulates, such as magnesium, calcium, aluminum, silicon, chromium, nickel, iron, barium, titanium, alkali metals and compounds thereof, including oxides, carbonates, phosphates, salts and mixtures thereof. These environmental contaminants are in addition to the corrosive and oxidative contaminants that result from the combustion of fuel. However, all of these contaminants can adhere to the surfaces of the hot section components, which are typically thermal barrier coated.
[0005] At the operating temperature of the engine, these contaminants can form contaminant compositions on the thermal barrier coatings. These contaminant compositions typically include calcium, magnesium, alumina, silica (CMAS), and their deposits are referred to as CMAS. At temperatures above about 2240° F., these CMAS compositions may become liquid and infiltrate into the TBC. This infiltration by the liquid CMAS destroys the compliance of the TBC and leads to premature spallation of the TBC.
[0006] The spallation due to CMAS infiltration has become a greater problem in jet engines as their operating temperatures have increased to improve efficiency, as well as in engines operating in the Middle East and in coastal regions. High concentrations of fine sand and dust in the ambient air can accelerate CMAS degradation. A typical composition of CMAS is, for example, 35 mole % CaO, 10 mol% MgO, 7 mol % Al 2 O 3 , 48 mol % SiO 2 , 3 mol % Fe 2 O 3 and 1.5 mol % NiO. And of course, spallation of the TBC due to exposure to CMAS at elevated temperature only sets the stage for more serious problems. Continued operation of the engine once the passive thermal barrier protection has been lost leads to oxidation of the base metal superalloy protective coating and the ultimate failure of the component by burn through cracking. In fact, such significant distress has been observed in both military and commercial engines.
[0007] Various solutions to the problem of CMAS degradation have been attempted. However, as operating temperatures of engines have gradually trended higher, ever more effective treatments are required. One early solution, identified in U.S. Pat. No. 6,261,643 issued Jul. 17, 2001, and assigned to the assignee of the present invention, identifies the use of an impermeable barrier or a sacrificial oxide coating applied over the TBC. One of these barrier oxide coatings is identified as alumina particles in a silica matrix, as set forth in U.S. Pat. No. 6,465,090 issued Oct. 15, 2002, and assigned to the assignee of the present invention. This can be effective until these thin barrier layers are worn off or sacrificially consumed.
[0008] Other solutions have been set forth in U.S. Pat. No. 6,893,750 issued May 17, 2005, (the '750 patent) and U.S. Pat. No. 6,933,066 issued Aug. 23, 2005, (the '066 patent), both assigned to the assignee of the present invention. Both the '750 patent and the '066 patent disclose the use of a ceramic thermal barrier coating material applied directly to a bond coat overlying the metal substrate. The '750 patent further discloses an alumina-zirconia layer overlying the ceramic TBC, whereas the '066 patent utilizes a tantalum oxide layer overlying the ceramic TBC. Suitable ceramic TBC materials are identified as various zirconias, in particular chemically stabilized zirconias (i.e., various metal oxides such as zirconium oxide blended with yttrium oxide), including yttria-stabilized zirconias, ceria-stabilized zirconias, calcia-stabilized zirconias, scandia-stabilized zirconias, magnesia-stabilized zirconias, india-stabilized zirconias, ytterbia-stabilized zirconias as well as mixtures of such stabilized zirconias. Suitable yttria-stabilized zirconias are identified as comprising from about 1 to about 20% by weight yttria (based on the combined weight of yttria and zirconia), and more typically from about 3 to about 10% by weight yttria. Yttria-stabilized zirconia having 7% by weight yttria (7YSZ) and 8% by weight yttria (8YSZ) are by far the most commonly used stabilized zirconia. Unless otherwise noted, all compositions are identified in weight percentages. These stabilized zirconias may be further identified as combined with one or more of a second metal (e.g., a lanthanide or actinide) oxide such as dysprosia, erbia, europia, gadolinia, neodymia, praseodymia, urania, and hafnia to further reduce thermal conductivity of the thermal barrier coating. Suitable ceramic TBC materials are also identified as including pyrochlores of general formula A 2 B 2 O 7 where A is a metal having a valence of 3+ or 2+ (e.g., gadolinium, lanthanum, neodymium, or erbium) and B is a metal having a valence of 4+ or 5+ (e.g., hafnium, titanium, cerium or zirconium) where the sum of the A and B valences is 7. Representative materials of this type include gadolinium-zirconate, lanthanum zirconate, cerium zirconate, lanthanum titanate, yttrium zirconate, lanthanum hafnate, aluminum cerate, cerium hafnate, aluminum hafliate and lanthanum cerate.
[0009] The '750 patent and the '066 patent fail to recognize that TBC-coatings that include lanthanum series additions are useful in protecting the substrate from CMAS infiltration. The amounts of the lanthanum series additions are not identified, so it may well be that the descriptions are either prophetic or included low levels of lanthanum series additions below the effective level, such as may be expected if these lanthanum oxide additions were weight percentage partial substitutions for yttria used to stabilize the zirconium oxide up to about 20%. This is further supported by the fact that neither the '750 patent or the '066 patent recognize the advantage of utilizing a ceramic TBC coating that includes an effective amount of a lanthanum series addition in the TBC overlying the bond coat applied over the metallic substrate.
[0010] Although the exact mechanism for spalling of TBC's from their substrates is not known, it has been the belief until now that the fracture toughness of the TBC coatings containing high weight percentages of lanthanum series elements is significantly lower than that of the underlying bond coat and base metal superalloy. This difference in fracture toughness was believed to result in fracture and spallation at the interface after a limited number of engine cycles. Thus, the solutions provided by both the '750 patent and the '066 patent are different solutions than that presented by the present invention.
[0011] What is needed is a TBC system that is resistant to CMAS penetration at elevated temperatures, but is also resistant to both spallation at elevated temperatures in the absence of CMAS and excessive wear from normal engine operation.
SUMMARY OF THE INVENTION
[0012] The present invention provides a thermal barrier coating system that is resistant to attack by CMAS infiltration for use with hot section components, while providing excellent resistance to spallation as a result of engine cycling. The TBC system of the present invention can be tailored to prevent infiltration by the liquid phase of CMAS at temperatures as high as 2800° F. The trend for gas turbine engines is toward higher operating temperatures, so the present invention will also be capable of supporting subsequent improvements in gas turbine engine design.
[0013] The coating of the present invention is specifically applied as a two-layer system. The outer layer is an oxide of a group IV metal selected from the group consisting of zirconium oxide, hafnium oxide and combinations thereof, which are doped with an effective amount of a lanthanum series oxide. These metal oxides doped with a lanthanum series addition comprises a high weight percentage of the outer coating. As used herein, lanthanum series means an element selected from the group consisting of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu) and combinations thereof, and lanthanum series oxides are oxides of these elements. When the zirconium oxide is doped with an effective amount of a lanthanum series oxide, a dense reaction layer is formed at the interface of the outer layer of TBC and the CMAS. This dense reaction layer prevents CMAS infiltration below it. The second layer, or inner layer underlying the outer layer, comprises a layer of partially stabilized zirconium oxide. The most well known of these are YSZ, or yttria-stabilized zirconia, where yttria is present in the amount of from about 2%-8% by weight.
[0014] The present invention finds its use as a component of thermal barrier coating system applied over hot section components of gas turbine engines. The present invention provides the TBC system with resistance to CMAS infiltration. Since CMAS results from the deposition of environmental contaminants found in the flowpath air, such as sand, dirt, volcanic ash, sulfur in the form of sulfur dioxide, fly ash flow path, particles of cement, runway dust, and other pollutants on hot section components in the presence of very high temperatures, there is no known way to prevent its formation in advanced turbine engines. However the TBC coating system of the present invention prevents the infiltration of the CMAS below an outer layer of a two layer zirconium-based coating, thereby preventing complete spallation of the TBC from the hot section components. The outer layer, zirconium-based oxide material, a hafnium-based oxide material and combinations thereof, doped with an effective amount of a lanthanum series based oxide, wherein the lanthanum series based oxides are selected from oxides of the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu and combinations thereof. The outer layer interacts with the liquid CMAS to form a dense layer preventing further infiltration of the CMAS. Small amounts of these lanthanum series based oxides will not interact sufficiently to form the requisite dense layer. An effective amount will form the dense layer preventing further infiltration of the CMAS into the TBC. In addition, the effective amount will vary, depending upon which lanthanum series oxide or combination of oxides is selected.
[0015] The inner layer of the zirconium-based coating is a stabilized zirconia layer, such as 7YSZ, as is well known in the art. This layer is not susceptible to attack from CMAS as it is protected by the outer layer. Thus, the expense associated with applying a complex inner layer can be eliminated. The inner layer also acts as a compliant layer underneath the outer layer and over a metallic bond coat. The inner layer also serves to reduce spalling of the zirconium-based coating, which otherwise occurs when an outer layer composition is applied directly to a bond coat. In addition to 7YSZ, suitable compositions for the inner layer are disclosed in U.S. Pat. No. 6,887,585 issued on May 3, 2005, to Darolia et al. entitled “Thermal Barrier Coatings Having Lower Layer for Improved Adherence to Bond Coat” and assigned to the assignee of the present invention and in U.S. Pat. No. 6,858,334 issued on Feb. 22, 2005, to Gorman et al. entitled “Ceramic Compositions for Low Conductivity Thermal Barrier Coatings,” assigned to the assignee of the present invention, both of which are incorporated herein by reference.
[0016] In particular applications or areas of a component, the operating temperature may not be high enough to melt or cause the CMAS to adhere to the surface. In this situation, the CMAS is erosive to the TBC. TBC with effective additions of lanthanum series oxides are known to have poor erosion resistance compared to 7YSZ. Therefore, the inner layer further protects the component or areas of the component in which the CMAS is prone to cause erosion damage rather than infiltration damage.
[0017] The hot section component typically comprises a high temperature superalloy article having a metallic bond coat. The bond coat typically is characterized as an overlay MCrAlY, although it may also be a diffusion aluminide, such as a simple aluminide (NiAl) or a platinum modified aluminide ((Ni,Pt)Al). The bond coat forms a thin, tightly adherent aluminum oxide layer, commonly known as a thermally grown oxide (TGO), which acts as an adhesion layer between the TBC and the bond coat. The bond coat also provides oxidation protection to the underlying substrate.
[0018] An advantage of the present invention is that it can be utilized to prevent CMAS damages to hot section engine components that also are exposed to the environmental contaminants found in flow path air.
[0019] Another advantage of the present invention is that it can be used to replace TBC coatings in current engines during retrofit or overhauls and it can be used on new engine designs and engine variants that can experience temperatures in excess of about 2800° F.
[0020] Still another advantage of the multilayer coating of the present invention is that it will not completely spall from the hot section component even after exposure to a large number of engine cycles and the accompanying temperature transients.
[0021] A further advantage of the present invention is the elimination of an expensive and complex inner layer. This allows for the use of a simple and lower density YSZ layer as an inner layer.
[0022] A further advantage of the present invention is that, in an erosive environment, the underlayer provides improved erosion resistance in lower temperature applications.
[0023] Yet advantage of the present invention is that it can be applied in different thicknesses to different components consistent with the mechanical operating conditions experienced by the components and still afford protection from CMAS infiltration to the components.
[0024] Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 depicts a cross-section of the present invention applied to a component substrate before being placed into service.
[0026] FIG. 2 depicts a cross-section of a substrate coated with the present invention at 300 magnification after exposure to CMAS at 2350° F. for one hour.
[0027] FIG. 3 depicts a cross-section of a substrate coated with the present invention after exposure to CMAS at 2350° F. for one hour, showing the location of microprobe sampling at six locations.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention is a multi-layer thermal barrier coating system that is resistant to CMAS infiltration for application to a substrate of hot section components of gas turbine engines that are exposed to environmental contaminants resulting in CMAS deposits during normal gas turbine operation. Referring now to FIG. 1 , the thermal barrier coating system typically is applied over the substrate surface 10 of a component 12 . The substrate 14 typically is a superalloy material, which is coated with a bond coat 16 . A zirconium-based coating 18 overlies the bond coat to provide the requisite CMAS infiltration resistance. It will be understood by those skilled in the art that coating 18 of the present invention may include hafnium, partially or completely substituted for zirconium, and is used herein in that context. The zirconium-based coating 18 includes two layers, an inner layer 20 of partially stabilized zirconium oxide and an outer layer 22 overlying the inner layer 20 comprising a zirconium-based material doped with an effective amount of a lanthanum series based oxide, wherein the lanthanum series based oxides are selected from oxides of the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu and combinations thereof. The outer layer typically is sufficient to provide the requisite CMAS infiltration resistance. However, if desired, an optional coating 24 of alumina may be applied over the outer layer of the zirconium-based coating.
[0029] The material comprising the substrate 14 is typically a superalloy material, either a nickel-based, iron-based or cobalt-based superalloy material or a superalloy that is a combination of nickel, iron or cobalt. Typical airfoil alloys include nickel-based superalloys. Nickel-based superalloy materials are selected because they retain excellent mechanical properties as they rotate at high speeds under high temperature operation. Shrouds and vanes also are comprised of nickel-based superalloy materials. These components are not subject to the high stresses resulting from high rotational speeds, but they still must retain their mechanical properties as they are exposed to high temperatures and thermal stresses. In addition, these nickel-based superalloys typically are characterized by excellent corrosion resistance and oxidation resistance. However, because the operating temperatures of gas turbines approach or exceed the melting temperature of the superalloy materials, these components are protected from overheating by active cooling systems. The present invention provides a passive cooling system that is used in conjunction with an active cooling system.
[0030] The passive cooling system is typically a thermal barrier coating system. The thermal barrier coating system applied to the substrate surface 10 typically utilizes a bond coat 16 . The bond coat 16 usually is a metallic or an intermetallic material applied directly to the substrate surface 10 . This bond coat is added to improve the adhesion of the ceramic thermal barrier coating. The difference in properties between ceramic TBCs and superalloy substrates, including properties such as coefficient of thermal expansion (COE), toughness and fatigue strength etc. can be sufficiently great at elevated temperatures to cause a TBC to peel or spall from the substrate surface. Typical bond coats include MCrAlX alloys where M is an alloy selected from the group consisting of Fe, Ni, Co and combinations thereof and X is an element selected from the group of gamma prime formers, and solid solution strengtheners, consisting of, for example, Ta, Re or reactive elements, such as Y, Zr, Hf, Si, or grain boundary strengtheners consisting of B, and C and combinations thereof. Most typically, X is yttrium. Other materials used as bond coats are aluminides of Ni, Co, Pt, and combinations thereof. The bond coat also provides the additional advantage of providing additional oxidation and corrosion resistance.
[0031] In the present invention, overlying bond coat 16 is a zirconium-based coating 18 that provides the impedance to the transfer of heat directly to the material substrate. This zirconium-based coating comprises two layers, an outer layer 22 and an inner layer 20 .
[0032] The outer layer 22 is a ceramic material comprising a zirconium-based material doped with an effective amount of a lanthanum series based oxide, wherein the lanthanum series based oxides are selected from oxides of the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Lu and combinations thereof. How this layer reacts with CMAS is an important aspect of this invention. However, a layer having the composition of outer layer 22 when applied directly to a bond coat 16 spalls from the bond coat after a few engine cycles, and in some instances after just one engine cycle. The exact mechanism for spallation is not known. Without wishing to be bound by theory, it is believed to be due to lower fracture toughness of this layer, or at the interface between this thin layer and the TGO. The stresses at the interface are sufficiently high during engine cycling that the layer having the composition of the outer layer develops cracks and begins to spall.
[0033] To overcome the problem at the interface, it has been found that an inner layer 20 comprising a partially stabilized zirconia applied over bond coat 16 eliminates the problem of spalling. Partially stabilized zirconia includes zirconia stabilized with yttria from 2% to about 10% by weight. Unless specifically indicated otherwise, all percentages are provided as weight percentages. This stabilized zirconia is referred to as 2YSZ to 10YSZ. A preferred stabilized zirconia is 7YSZ that is a zirconia stabilized with 7 w/o yttria. The outer layer 22 bonds to the inner layer 20 , and the stresses at the interface between these layers during engine cycling are insufficient to cause spalling. Similarly the stresses at the interface between inner layer 20 and TGO on top of the bond coat 16 are also insufficient to result in spalling.
[0034] Reference is now made to FIG. 2 . FIG. 2 depicts a coating having a composition within that contemplated by the present invention applied over an alumina substrate. With reference to FIG. 1 , this coating initially has an inner layer 20 comprising 7YSZ and an outer layer 22 comprising about 64.8% Nd 2 O 3 -35.2% ZrO 2 by weight. FIG. 2 differs from the present invention only in that it does not include a bond coat applied over a nickel-based substrate, but rather utilizes an alumina substrate to facilitate high temperature evaluation. Since FIG. 2 solely illustrates the mechanism of the present invention in preventing CMAS infiltration, while the purpose of the bond coat over a nickel-based substrate is discussed above, this difference is not significant. Alumina substrate 30 is overlaid with an initial coating that falls within the composition of the present invention, as discussed above. Referring again to FIG. 2 , coating 32 includes an inner layer 40 and an originally-applied outer layer 42 . After exposure to CMAS at elevated temperatures, the originally applied outer layer 42 includes a reaction zone 44 , an unaffected zone 46 and a dense layer 48 between the reaction zone 44 and the unaffected zone 46 . Overlying reaction zone 44 is a layer 50 of CMAS deposit. At the high temperature of engine operation, CMAS converts to a liquid. CMAS can undergo a change in state to a liquid at temperatures typically around 2240° F. A typical surface temperature of a gas turbine component with an applied TBC in an operating engine is about 2200° F. and above. In understanding the interactions, reference is again made to FIG. 1 . As the CMAS contacts the surface ( FIG. 1 ), a reaction zone forms at 44 as the molten CMAS interacts with a portion of outer layer 22 . This reaction zone 44 is characterized by a needle-like reaction product. As the reaction continues, a dense layer 48 forms in outer layer 22 . However, this dense layer 48 prevents further infiltration of CMAS to the unaffected zone 46 below dense layer.
[0035] A microprobe analysis of affected areas of the coating disclose compositional differences, likely resulting from high temperature reactions. The reaction zone 44 includes not only Zr and Nd, but also Al, Si, Fe, Ca, Mg and a small amount of Ni. The results of microprobe readings from two different areas in the reaction zone, as shown in FIG. 3 indicated as locations 1 and 2 , are provided in Table 1. This coating was exposed to CMAS at a temperature of 2350° F. for one hour. Oxide mole percentages are calculated for the various elements assuming that these elements form their respective oxides.
[0000]
TABLE 1
Estimated
Estimated
Weight percent
mole percent
Weight percent at
mole percent
Element
at Location 1
at Location 1
Location 2
at Location 2
ZrO 2
7.0
4.5
11.8
11.5
Nd 2 O 3
24.2
5.7
51.0
18.2
CaO
16.8
23.7
10.7
22.9
MgO
7.1
14.0
1.4
4.2
Al 2 O 3
12.5
9.7
1.6
1.9
SiO 2
29.3
38.7
20.6
41.2
Fe 2 O 3
7.4
3.7
—
—
[0036] The dense layer 48 composition also was measured in two locations indicated as 3 and 4 in FIG. 3 . Its composition was different from reaction zone 44 . This dense layer appears to form a barrier that is impenetrable for the CMAS. Differences in the weight percentage of Nd, Zr and other elements are likely the result of the initial concentration gradients in outer layer 42 . Initial penetration and reaction of the coating with CMAS prior to or during the formation of dense layer 48 also probably contributes to compositional differences. Although there is some variance in the weight percentage of Zr and Nd in outer layer 42 , due to multiple phase structures, it should be noted that the average weight percentage is very high relative to the amount of yttrium and its equivalents used to stabilize YSZ TBCs. The results of microprobe readings from two different locations, indicated as 3 and 4 in FIG. 3 , in the dense layer 48 are provided in Table 2.
[0000]
TABLE 2
Estimated
Estimated
Weight percent
mole percent
Weight percent
mole percent
Element
at Location 3
at Location 3
at Location 4
at Location 4
ZrO 2
13.5
16.2
16.7
28.6
Nd 2 O 3
59.6
26.2
65.1
26.2
CaO
6.6
17.4
1.5
5.6
Al 2 O 3
—
—
1.4
2.9
SiO 2
16.4
40.3
4.4
15.4
Fe 2 O 3
—
—
5.1
6.7
[0037] The outer layer 46 below dense layer 48 is substantially unaffected by CMAS. Any variations in the weight percentage of Nd and Zr likely are the result of initial concentration differences in the outer layer resulting from deposition conditions due to, for example, differences in their vapor pressures. The results of microprobe readings from two different locations, shown as 5 and 6 in FIG. 3 , in the unreacted outer layer 46 are provided in Table 3.
[0000]
TABLE 3
Weight
Estimated
Estimated mole
percent at
mole percent at
Weight percent
percent at
Element
Location 5
Location 5
at Location 6
Location 6
ZrO 2
14.2
31.2
26.7
49.9
Nd 2 O 3
85.8
68.8
73.3
50.1
[0038] The coating of the present invention can be used in dramatically different applications. The applications include static applications as well a rotating applications. Consideration must be given to the operations of the engine in each of the various applications to determine how the coating of the present invention is to be applied.
[0039] Shroud assemblies are examples of static applications. Shroud assemblies are designed to accommodate severe temperature excursions of the engine. During these severe temperature excursions, the rotating apparatus (i.e. the rotating blades) may wear into the shroud assemblies. The shroud assemblies are designed to accommodate this wear. The application of the coating of the present in invention to a shroud must accommodate this wear, since the rotating assemblies will wear into the shroud assembly and remove the outermost layers of the shroud assemblies. Since the coating of the present invention is applied to the shroud assemblies as its outermost layer, the coating must be applied to a sufficient thickness to accommodate this wear. It is anticipated that the coating of the present invention must be applied on a static assembly, such as a shroud assembly which will experience wear from moving parts to a total coating thickness of up to 80 mils (0.080 inches) and preferably 20-70 mils (0.020-0.070 inches). Furthermore, the wear must not be so great so as to remove all of outer layer 22 , exposing inner layer 20 . Thus, in this application, not only must the outer layer be thicker than the inner layer, but the initial ratio of the thickness of the outer layer 22 to the inner layer 20 must be high. The ratio of thickness of the outer layer to the inner layer ideally should be from about 0:15 to about 7:1. This inner ceramic coating is applied over a bond coat 16 . The inner ceramic coating has a thickness of about from 5-40 mils (0.005-0.040 inches), and preferably from about 20-40 mils (0.002-0.040 inches). The preferred outer coating thickness for use with this inner coating thickness is about 20-70 mils (0.020-0.070 mils). Maintaining these ratios are key, because after initial wear-in, as the rotating apparatus contacts the stationary shrouds, sufficient material must remain in the outer layer to shield the coating from CMAS penetration. Thus, loss of coating material due to wear should be estimated when applying the layers. The thickness of the outer layer should meet the design intent for the application.
[0040] By contrast, turbine blades, which are rotating parts, do not require as thick of a coating. The coating of the present invention is applied to the airfoil section of a turbine blade. For the purposes of this discussion, the airfoil section of a turbine blade is that portion above the platform, or above the dovetail if the blade design does not include a platform. The airfoil section extends into the hot stream of gases resulting from combustion of fuel, also referred to as the gas flow path. The tip portion of the airfoil, which is opposed to the shroud, wears into the shroud during temperature excursions. As the overall thickness of coatings applied to blade tips is thin because of weight considerations, any coating applied to this tip portion will abrade away as a result of this contact. However, the adjacent areas of the tip extending downward from the tip portion toward the dovetail do not experience regular contact with other engine parts, but still require protection as they extend into the gas flow path. The coating applied to these surfaces can be significantly thinner than that applied to wear surfaces such as shrouds. The overall coating thickness in such applications can vary from about 4-15 mils (0.004-0.015 inches), and preferably is 4-10 mils (0.004-0.010 inches). The outer layer thickness can vary from about 0.5 mils to about 5 mils (0.0005-0.005 inches) and preferably is from 1-3 mils (0.001-0.003 inches). The ratio of thickness of the outer layer 22 to inner layer 20 is about 0.05:1 to about 0.5:1. This ceramic coating is applied over a bond coat having a thickness of from about 1-6 mils (0.001-0.006 inches). An optional alumina coat may be applied over the outer layer 22 of zirconium-based coating 18 . The preferred thickness of this optional alumina coating 24 is about 0.2-1 mil (about 0.0002-0.001 inches).
[0041] Other hot section components that are not wear parts and are not rotating parts would be expected to have a coating with a thickness similar to that used for turbine blades. If erosion from hot gases is an anticipated problem, the thickness of the coating may be increased slightly beyond the upper thickness limit described above. For example, turbine vanes, which are stationary, would have a coating thickness very similar to that of the turbine blades.
[0042] The ceramic coating of the present invention is a two-layer zirconium-based coating that includes an effective amount in the outer layer of a lanthanum series based oxide, wherein the lanthanum series based oxides are selected from oxides of the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and combinations thereof. The inner layer is a partially stabilized YSZ wherein yttria is present in the amount of from 2-8%, and preferably is 7YSZ-8YSZ. The ceramic coating of the present invention is the effective CMAS infiltration inhibitor in a coating system that includes a bond coat applied over a component substrate, wherein the component substrate preferably is a hot section gas turbine superalloy component. The ceramic coating is applied with the inner layer in contact with the bond coat and the outer layer facing the hot gas turbine environment. Optionally, a very thin topcoat of alumina may be applied over the outer layer for additional protection in applications in which wear is not a concern.
[0043] It is known that a substitution of lanthanum group oxide for yttria at a level sufficient for stabilization of zirconia, (about 2-10 weight percent yttria) in YSZ is not effective in preventing CMAS infiltration. Prior art attempts to solve the problem included either (1) a layer of alumina, or (2) a layer of tantalum oxide over an outer layer that included a lanthanum series oxide substituted for yttria in the outer zirconium-based layer or (3) alumina codeposited in an outer layer in which lanthanum series oxide is substituted for yttria in the outer layer. In this latter embodiment, because alumina is codeposited in amounts greater than 50 %, the outer layer is no longer zirconium-based.
[0044] An effective amount of the lanthanum series oxide in outer layer 22 includes more than 20 mole percent of the lanthanum series oxide with the balance being zirconia. As previously note, the present invention also contemplates hafnia (HfO 2 ) substituted partially or completely for zirconia, both in outer layer 22 and/or inner layer 20 . Preferably the lanthanum series oxide is greater than 20 mole percent with the balance zirconia. Most preferably the lanthanum series oxide is greater than about 30 mole percent by weight. However, the lanthanum series oxide can comprise from greater than 20 mole percent to 60 mole percent of the outer layer, and the zirconium-based material comprises the balance, typically from about 40 to less than 80 mole percent. When the lanthanum series oxide is less than 50 mole percent, the zirconium-based material compromises a cubic zirconia phase. However, in the range of 50-60 mole percent lanthanum series oxide, more specifically, at greater than 20 mole percent lanthanum series oxide, the zirconium-based material can be present as pyrochlore, having the formula Zr 2 X 2 O 7 where X is a lanthanum series element. The present invention also contemplates complex pyrochlores of (Hf 2 Zr 2 )X 2 O 7 . While any of the lanthanum series elements in oxide form should be effective, preferred lanthanum series elements, in oxide form includes Gd, La, Eu, Sm and Nd. The structure tested and depicted in FIG. 2 nominally included 40 mole percent Nd 2 O 3 and 60 mole percent ZrO 2 , by mole in the ceramic material forming outer layer 22 of the ceramic coating and nominally 7YSZ in the ceramic material forming inner layer 20 . Again, the difference between the measured composition in the outer layer 22 and the nominal composition is likely due to initial concentration gradients, phase structures and CMAS reactions.
[0045] It is also noted that an embodiment tested with a ceramic coating having an inner layer 20 of 7YSZ and an outer layer 22 of 52.6% Yb 2 O 3 -47.4% ZrO 2 by weight was ineffective in forming a dense layer that prevented infiltration of CMAS. CMAS infiltrated both the outer layer 22 and the inner layer 20 . In an engine undergoing multiple engine excursions, such an infiltrated ceramic coating would spall. In this example, 52.6% Yb 2 O 3 is an ineffective amount of oxide. It is expected that the effective amount of oxide will vary depending upon the lanthanum series oxide or combinations of oxides selected for inclusion in the outer layer. However, determining the effective amount for the lanthanum series oxide or combinations of oxides is within the skill of the artisan.
[0046] The ceramic coating of the present invention may be applied by any convenient method. The method of application is likely determined by the component to be coated. Shroud assemblies require thick coatings, but are relatively simple shapes. Methods such as thermal spray processes, used in depositing TBCs, can be used to apply both the inner layer 20 and the outer layer 22 to the bond coat. Thermal spray processes are inexpensive and relatively quick methods for applying a thick coating to a surface. These generally are line of sight processes. Thermal spray processes include air plasma spray, vacuum plasma spray, low pressure plasma spray, HVOF and other related methods. Thin coatings are required on structures such as blades. These require more precise controls. Physical vapor depositions are preferred for these applications. Electron beam methods (EB-PVD) are the most preferred method for applying thin coatings of the present invention to articles such as blades.
[0047] While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
|
A coating applied as a two layer system. The outer layer is an oxide of a group IV metal selected from the group consisting of zirconium oxide, hafnium oxide and combinations thereof, which are doped with an effective amount of a lanthanum series oxide. These metal oxides doped with a lanthanum series addition comprises a high weight percentage of the outer coating. As used herein, lanthanum series means an element selected from the group consisting of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu) and combinations thereof, and lanthanum series oxides are oxides of these elements. When the zirconium oxide is doped with an effective amount of a lanthanum series oxide, a dense reaction layer is formed at the interface of the outer layer of TBC and the CMAS. This dense reaction layer prevents CMAS infiltration below it. The second layer, or inner layer underlying the outer layer, comprises a layer of partially stabilized zirconium oxide.
| 5
|
BACKGROUND OF THE INVENTION
The present invention relates to a circuit for generating a substrate bias voltage, more especially to a substrate-bias-voltage-generating circuit which prevents malfunctions of the circuits arranged near by due to unavoidable forward biasing of a pn junction in the substrate-bias-voltage-generating circuit during operation and the resultant injection of minority carriers to the semiconductor substrate.
Recent semiconductor integrated circuits tend to be operated by a single source, such as +5 V. Semiconductor memory devices, however, sometimes require negative direction bias voltage. In such cases, the semiconductor integrated circuit is provided with a substrate-bias-voltage-generating circuit which forms negative direction bias voltage from the +5 V source.
For example, semiconductor integrated circuit devices (IC's) formed by n channel insulated gate field effect transistor's (MIS FET's) have the capacitance decreased in the pn junction formed between the MIS FET source region and drain region and the semiconductor substrate. This increases circuit operating speed and the MIS FET threshold voltage is controlled within the desired value by the application, to the semiconductor substrate forming the MIS FET, of a substrate bias voltage having a polarity which reverse biases the pn junction, for example, in an n channel metal-oxide semiconductor (MOS) IC, i.e., a substrate bias voltage of negative polarity. Such substrate bias voltage is given a polarity opposite to the electric source voltage supplied to the IC.
When forming said substrate-bias-voltage-generating circuit, however, the formation of the necessary semiconductor rectifier circuit, for example, an enhancement type channel FET on the semiconductor substrate inevitably results in the formation of a junction diode between the FET source and drain and the semiconductor substrate and, thereby, minority carriers are injected into the semiconductor substrate. This results in malfunctions in the circuits arranged near the substrate-bias-voltage-generating circuit.
SUMMARY OF THE INVENTION
An object of the present invention is to control the current which flows in the above-mentioned junction diode to a level able to prevent malfunctions of peripheral circuits.
Another object of the present invention is to provide a substrate-bias-voltage-generating circuit able to maintain its function even if the above-mentioned junction diode is formed.
The above-mentioned objects can be achieved by a substrate-bias-voltage-generating circuit in a semiconductor substrate comprising: means for providing a reference voltage level; first and second rectifier circuits; a capacitor having first and second terminals, the first terminal being connected via the first rectifier circuit to the semiconductor substrate and connected via the second rectifier circuit to a reference voltage level; an oscillator circuit which generates a periodic signal; a drive circuit including a positive direction drive circuit which receives the output of the oscillator circuit and which forwardly drives the second terminal of the capacitor and a negative direction drive circuit which receives the output of the oscillator circuit and which reversely drives the other terminal of the capacitor element; and a current limiting circuit for limiting the peak valve of the current in the capacitor when the first rectifier circuit is placed in the conductive state.
Further features and advantages of the present invention will be apparent from the ensuing description with reference to the accompanying drawings to which, however, the scope of the invention is in no way limited.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a block diagram of one example of a conventional substrate-bias-voltage-generating circuit;
FIG. 2 is a sectional view of the construction of the circuit shown in FIG. 1;
FIG. 3 is a diagram of waveforms in essential portions of the circuit shown in FIG. 1;
FIGS. 4A and 4B are block diagrams of one embodiment of a substrate-bias-voltage-generating circuit according to the present invention;
FIG. 5 is a diagram of wavforms in essential portions of the circuit shown in FIG. 4A;
FIG. 6 is a block diagram of another embodiment of the circuit according to the present invention;
FIG. 7 is a diagram of waveforms in essential portions of the circuit shown in FIG. 6; and
FIGS. 8, 9, 10, 11, and 12 are block diagrams of further embodiments of the circuit according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a conventional substrate-bias-voltage-generating circuit. In FIG. 1, reference numeral 1 denotes an oscillator circuit, 2 is a capacitor, 3 is an inverter, Q 1 , Q 2 , Q 3 , and Q 4 are MOS transistors, A and B are points of reference for FIG. 3, C is an output terminal, and E is ground.
FIG. 2 is a sectional view showing the relation between MOS transistors of the substrate-bias-voltage-generating circuit, a junction diode and a transistor in a peripheral circuit near the substrate-bias-voltage-generating circuit. In FIG. 2, reference numeral 4 denotes a p type semiconductor substrate, 5 is silicon dioxide, 6 is an insulation film, 7 is a wire layer, Q 3 and Q 4 are the MOS transistors of the substrate-bias-voltage-generating circuit, Q x is the transistor in the peripheral circuit, and E is ground. FIG. 3 illustrates the relation between voltage waveform points A and B in FIG. 1, a substrate bias voltage level at point C, and ground potential at point E.
In FIG. 1, the oscillator circuit 1 generates a square wave signal. The output of the oscillator circuit 1 is applied directly, or via inverter 3, to the gates of MOS transistors Q 1 and Q 2 . A high output of the oscillator circuit 1 places MOS transistor Q 1 in the ON state and MOS transistor Q 2 in the OFF state, thereby placing the diode-connected MOS transistor Q 4 in the ON state, connected via capacitor 2 to connection points of MOS transistor Q 1 and Q 2 , and charging the capacitor 2.
A low output of the oscillator circuit 1 places MOS transistor Q 1 in the OFF state and MOS transistor Q 2 in the ON state, thereby discharging capacitor 2 and placing MOS transistor Q 4 in the OFF state. This lowers the potential at point B. When the potential at point B falls below the value of the potential at output terminal C minus the threshold voltage of MOS transistor Q 3 the diode-connected MOS transistor Q 3 is in the ON state. This discharges capacitor 2 and the discharged current flows from the drain to the source of MOS transistor Q 3 , thereby causing a lower voltage than ground potential to be generated at output terminal C. Thus, capacitor 2 and MOS transistors Q 3 and Q 4 for a substrate-bias-voltage-generating circuit.
In the circuit shown in FIG. 1, the flow of current through MOS transistors Q 2 and Q 3 generates a peak voltage as shown in FIG. 3. MOS transistor Q 3 cannot handle all the current. The current thereupon flows through the undesirably formed diode Q 5 and causes injections of minority carriers to the substrate. In this condition, any transistor, such as Q x shown in FIG. 2, memory cell, or circuit, carrying out dynamic operation near the substrate-bias-voltage-generating circuit has its information inverted by minority carriers. This problem is especially serious in a low temperature state where the life of minority carriers is long. This problem can be eliminated by the embodiment of the present invention described hereinafter.
FIG. 4A shows a fundamental embodiment of the circuit according to the present invention. The circuit is characterized by the provision of a constant current circuit 8 between MOS transistors Q 1 and Q 2 so as to limit the peak voltage caused by the current flowing in the capacitor 2 when the rectifier circuit of MOS transistor Q 3 is conducting, thereby preventing conductance of the diode 5. For a constant current circuit 8, a depletion type MOS transistor connected as shown in FIG. 4B can be used. FIG. 5 illustrates voltage waveforms at points A, B, C in FIG. 4A. In FIG. 5, "a" denotes an output waveform of the oscillator circuit 1.
FIG. 6 illustrates a particular embodiment of the substrate-bias-voltage-generating circuit according to the present invention. In the circuit shown in FIG. 6, 11 denotes an oscillator circuit. The output of oscillator circuit 11 is supplied to a control input of a positive direction drive circuit 12 which is connected to one electrode of a capacitor or other charge-accumulating element 13. The above-mentioned one electrode of the capacitor 13 is further connected to a negative-direction drive circuit 14. A control input of the negative-direction drive circuit 14 is connected to the output of the oscillator circuit 11. A circuit 15 for limiting the negative-direction drive current is provided in the negative-direction drive circuit 14. Another electrode of the capacitor 13 is connected to a semiconductor rectifier circuit 16 formed in the semiconductor substrate. Q 5 denotes the junction diode formed when the rectifier circuit is formed in the semiconductor substrate. The junction diode has a unidirectional property from the substrate to which the output of the rectifier circuit 16 is connected toward another electrode to which the rectifier circuit 16 is connected.
The thus constructed substrate-bias-voltage-generating circuit 10 has a positive-direction drive circuit 12 with a gate connected to the output of the oscillator circuit 11, a drain connected to the power supply Vcc, and a source connected to one electrode of the capacitor 13.
In the negative-direction drive circuit 14, the drain of an enhancement-type N-channel FET Q 6 , of which the gate is connected to the output of the oscillator circuit 11, is connected to the gate of an enhancement-type N-channel FET Q 2 via the constant current circuit or other circuit for limiting the negative-direction drive current 15; the drain of the transistor Q 2 is connected to one electrode of the capacitor 13, and the source of the transistor Q 2 is connected to ground potential or other reference potential. The source of the transistor Q 6 is also connected to ground potential.
The constant-current circuit 15 fundamentally comprises a depletion-type N-channel FET Q 7 , with the gate and source connected to the gate of the transistor Q 2 and with the drain connected to the power supply Vcc, and an enhancement-type N-channel FET Q 8 with the gate and drain connected to the gate of the transistor Q 2 and with the source connected to ground potential. For conveience, the connection portion from the source of transistor Q 7 to the drain of transistor Q 8 is referred to as the constant-current flowing portion.
Rectifier circuit 16 comprises enhancement-type N-channel MOS FET's Q 3 and Q 4 connected in series across the substrate and ground potential. The gates of these transistors are connected to their corresponding drains.
The operation of the thus constructed circuit of the invention will be described below. Pulses are supplied at a predetermined period from the oscillator circuit 11 to the positive-direction drive circuit 12 and to the negative-direction drive circuit 14, and the capacitor 13 is alternately driven to the positive direction and to the negative direction by circuits 12 and 14. Therefore, the average alternating current level of the other electrode C of the capacitor 13 becomes negative. FIG. 7 illustrates a time chart showing the relation of the output signal "a" of the oscillator circuit 11, an input voltage A of the capacitor 13, an output voltage B of the capacitor 13, the substrate bias voltage C, waveform D of the constant-current flowing portions, a threshold voltage Th of the transistor Q 3 , and ground potential E.
As shown in FIG. 7, when the output signal "a" of the oscillator circuit 11 is shifted to a low level, the output current of the constant-current circuit 15 is determined by the potential at the constant-current flowing portion of the transistors Q 7 , Q 8 and Q 2 . The thus determined current is of a level either not allowing any current to flow into the junction diode or allowing only a current smaller than a predetermined value to flow through the substrate, transistor Q 3 , capacitor 13, and transistor Q 2 . Therefore, even though diode Q 5 is formed in parallel with transistor Q 3 , injection of minority carriers to the semiconductor substrate via diode Q 5 can be prevented, whereby malfunctions of the peripheral circuits can be prevented.
In FIG. 8, an enhancement type N channel FET Q 9 is further provided in the circuit shown in FIG. 6. The transistor Q 9 is provided between the gate of the transistor Q 2 and the drain of the transistor Q 9 , and the gate of the transistor Q 9 is connected to the input terminal of the capacitor 13. Transistor Q 9 operates to raise the gate potential of transistor Q 2 in the negative direction, so that the conductivity of transistor Q 2 is increased and transistor Q 2 can complete the drive toward the negative direction.
FIG. 9 is a circuit which uses transistors having opposite polarity with respect to those used in FIG. 8 and which forms in the n type semiconductor substrate of the substrate-bias-voltage-generating circuit. The circuit shown in FIG. 9 can give the same effects as that of FIG. 8.
The above-mentioned embodiment has dealt with the case when the circuit for limiting the negative-direction drive current is made up of a constant-current circuit which comprises transistors Q 7 and Q 8 . However, there is no limitation on the circuit setup provided it is capable of maintaining the voltage which is applied to the gate of transistor Q 2 so that the above-mentioned conductivity is accomplished. Moreover, the circuit of the invention and the transistors may be those other than those of the type mentioned above.
FIG. 10 illustrates the embodiment where the present invention is applied to a complimentary MOS circuit (CMOS circuit). In the circuit shown in FIG. 10, transistors Q 11 and Q 12 correspond to Q 1 and Q 2 in FIG. 8; transistor Q 16 , correspond to Q 6 , and capacitor 17 and 18 is used in place of transistor Q 7 , and Q 8 and Q 9 . FIG. 11 is an embodiment where a semiconductor substrate opposite to the embodiment shown in FIG. 10 is used. The circuits shown in FIGS. 10 and 11 can be formed with low energy consumption by using a CMOS circuit. The present invention as applied to a CMOS circuit, can prevent latch-up.
Further, in the present invention, the voltage waveform shown in A of FIG. 7 falls with a constant current, therefore the period in the low voltage level of the output a of the oscillator circuit 11 shown in FIG. 7 must be long. This can be accomplished by forming the oscillator circuit 11 such that it is controlled by the driver output shown in FIG. 7 B or such that feedback is applied from the output point A of the transistor Q 1 , as shown in FIG. 12, to the oscillator circuit 11.
According to the present invention, as is obvious from the above description, the current which flows when the potential at one electrode of the capacitor 13 is driven toward the negative direction by the negative-direction drive circuit, is restricted to a value which does not permit the junction diode to pass current, the junction diode being formed together with the formation of the rectifier circuit. Therefore, the injection of minority carriers to the semiconductor substrate caused by the formation of the junction diode is eliminated. In forming the semiconductor rectifier circuit in the substrate, no attention is required toward the formation of the junction diode. The circuit of the present invention also exhibits merits possessed by the circuit of FIG. 1.
|
An oscillator circuit which generates a periodic signal is connected to an input side of a capacitor and the output side of the capacitor is connected via a rectifier circuit to a semiconductor substrate and also to a reference voltage potential. The characteristic feature of the present invention is to provide a current limiting circuit which limits the peak value of the current which flows in the capacitor when the rectifier circuit is placed in the conductive state.
| 6
|
CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Patent Application No. 61/124,045, filed Apr. 14, 2008, and is incorporated herein by reference.
FIELD OF THE INVENTION
This invention can be applied to the manufacture of cast components in which there is a requirement to control flow of metal into a casting mould.
BACKGROUND OF THE INVENTION
Currently the bottom pour crucible arrangement typically uses a metallic plug that melts shortly after the metal charge. A bottom pour system allows the molten metal to be removed from the bottom of the melt pool, thus minimizing the likelihood of any dross being entrained into the mould.
SUMMARY OF THE INVENTION
In one embodiment there is a method of initiating a pour of a liquid metal into a casting mould that comprises providing a crucible with an interior base having an opening closed by a plug. The plug is buoyant in the liquid metal having a metal head below a critical height. A displacement body is at least partially immersed in the liquid metal in the interior of the crucible so that the metal head is above the critical height. Pour is initiated by at least partially withdrawing the displacement body from the liquid metal until the metal head falls below the critical height.
In another embodiment there is a method of initiating a pour of a liquid alloy that comprises the steps of filling an interior of a crucible with a displacement plunger and the liquid alloy until a metal head of the liquid alloy exceeds a critical height. The crucible has a bottom pour opening with a plug inserted therein. The plug is configured to be buoyant within the liquid alloy when the liquid alloy is below the critical height. Pour is initiated by at least partially withdrawing the displacement plunger until the metal head drops below the critical height.
A number of refinements are contemplated with respect to each embodiment.
In one refinement the method further comprises superheating the liquid metal prior to initiating pour.
In another refinement the method further comprises melting the metal into the liquid state after positioning the displacement body in the interior of the crucible.
In another refinement the method further comprises melting the metal into the liquid state before positioning the displacement body in the interior of the crucible.
In another refinement the method further comprises completely withdrawing the displacement body from the liquid metal.
In another refinement the method further comprises completely withdrawing the displacement body from the interior of the crucible.
In another refinement the method further comprises wherein the plug provided with the crucible is ceramic.
In another refinement the method further comprises wherein the plug provided is made of alumina.
In another refinement the method further comprises wherein the displacement body is a ceramic bar.
In another refinement the method further comprises wherein the plug provided includes an extension passing through the opening in the base of the crucible.
In another refinement the method further comprises wherein the crucible and casting mould are moved closer to each other until the extension of the plug contacts the casting mould.
In another refinement the method further comprises restraining the plug while melting the metal until the metal head exceeds the critical height.
In another refinement the method further comprises the plug is restrained by a latch.
In another refinement the method further comprises disengaging the restraint from the plug after the metal head exceeds the critical height.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a cross sectional view of one embodiment of a bottom pour crucible having liquid metal therein with the buoyant plug retained in the bottom opening.
FIG. 2 is a cross section view of FIG. 1 after the displacement body has been withdrawn so that the metal head height is lowered below the critical height.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
This invention can be applied to control the flow of metal into a casting mould, and is especially useful in cases where it is necessary to superheat the alloy before pouring. A bottom pour crucible arrangement that uses a metallic plug that melts shortly after the metal charge does not allow the alloy to be superheated in a controllable manner.
In one embodiment of the present invention there is a buoyant plug to release molten alloy from a crucible into a casting mould at a defined and controllable time. The plug is preferably manufactured from a material that has a lower density than the alloy being poured (and/or is manufactured with one or more closed interior volumes). The plug is placed in an aperture in the base of the melting crucible. Although the plug would normally float in the molten alloy the pressure of the metal over the plug keeps it in place, thus blocking flow of the molten alloy through the aperture in the base of the crucible. Depending on the size of the plug, the size of the hole and the density difference between the alloy and the plug, there is a critical head height of alloy required to keep the plug in place. If the metal head height drops below this level, or the plug is displaced away from the hole, then the plug is able to float away, allowing the alloy to exit the crucible. This initiation event can be undertaken at any time, thus enabling the alloy to be superheated. Thus, the molten alloy may be contained inside the melting crucible until a particular set of conditions (such as superheating) are reached before the alloy is released into the mould. The buoyant plug arrangement does not rely on the melting of the plug, or the use of complex mechanical arrangements to contain the alloy.
One embodiment is to use a crucible with a hole in the bottom similar to the bottom pour crucibles in use for small bore furnace casting. The molten alloy is preferably retained in the crucible by a ceramic plug, manufactured from alumina for example, placed in the bottom of the crucible. The density of the plug is engineered so that a metal head greater than the critical head height keeps the plug in place during the superheating portion of the process. The head height in the crucible is allowed to fall when the preferred superheat is reached in the metal. One method of lowering the metal head below the critical head height is through the use of a movable displacement body that is at least partially immersed in the molten alloy. The displacement body might be, for example, a ceramic bar. The displacement body is at least partially, if not fully, withdrawn from the molten alloy (and might be completely removed from the interior of the crucible). This changes the amount of the load retaining the plug and it is possible to engineer the density of the plug sufficiently to allow it to be buoyant and float away. The molten alloy is now able to exit the crucible through the hole in the bottom of the crucible.
With reference to FIGS. 1 and 2 , there is illustrated an embodiment of the present invention in which molten alloy 30 is retained within interior 60 defined by inner wall 56 of a crucible 50 . While the present application will utilize the term alloy, it is defined to conclude super alloys and elemental metals unless specifically provided to the contrary. Crucible 50 is a bottom pour crucible that defines an opening 55 in the base 58 . Molten alloy 30 is retained in the crucible 50 by a ceramic plug 110 , manufactured from alumina for example, placed in the opening 55 in the base 58 of crucible 50 . The density of the plug 110 is engineered so that a metal head “h” greater than the critical head height “H” keeps the plug 110 in place until the controlled initiation of pouring is desired. In one refinement such pour is not initiated until a superheating condition exists in the molten alloy 30 . One form of the present application contemplates that a quantity of un-melted metal is utilized to keep the ceramic plug 110 in place within the opening 55 until the required critical head height “H” of molten metal is provided in the crucible. The quantity of un-melted metal can be placed upon the ceramic plug 110 to keep the plug in the opening 55 until the head height of molten metal has taken over holding the plug in a closed position. In another aspect the present application contemplates mechanical mechanisms for latching and/or holding the ceramic plug 110 in a closed position until the desired critical head height “H” of molten metal is accumulated.
With reference to FIG. 1 there is illustrated a displacement body 75 that is immersed in the molten alloy 30 within crucible 50 . Displacement body 75 occupies a volume such that the metal head “h” is a height 122 that is greater than the critical head height “H” 120 necessary to retain the plug 110 within the aperture 55 in the base 58 . At some later point in time, pour is initiated by at least partially withdrawing the displacement body 75 from the molten alloy 30 as illustrated in FIG. 2 . The metal head “h” is a height 118 less than the critical head height “H” 120 . Thus, buoyant plug 110 floats free and molten alloy exits via orifice 55 in the base 58 of crucible 50 .
It should be understood that the displacement body 75 is illustrated as having a paddle shaped cross section, but may take on any of a wide variety of shapes and sizes. While the displacement body 75 is illustrated as fully withdrawn from the interior 60 of the crucible 50 in FIG. 2 , it should be understood that, depending on the fill level and the critical head height “H”, the body 75 might only need to be partially withdrawn in order to drop the metal head below a height of “H”. That is to say, it is contemplated that the displacement body 75 might still be partially immersed in the molten alloy 30 when the metal head “h” fall below the critical head height “H” to initiate pouring. Also, if preferred, the crucible 50 might have a closed and/or pressurized interior.
In another embodiment of a bottom pour crucible system the buoyant (preferably ceramic) plug is modified. The plug includes a stem that extends through the hole and further extends beneath the base of the crucible. At the desired pour time the ceramic mould that receives the molten metal is elevated to contact the plug extension and lift the plug into the crucible. The metal can then pour from the crucible into the mould. Alternatively, the mould might remain stationary and the crucible might be lowered until the stem contacts the mould and lifts the plug into the crucible.
The plug 110 and the corresponding seat in the opening 58 are contemplated herein as taking on a variety of sizes and shapes. In one form the plug is tapered and matches with a tapered seat in the opening 58 . In another form the shape of the plug matches the shape of the seat in the opening. The present application is not limited to the fore mentioned shapes and also fully contemplates a mismatch between the shapes of the plug and the seat so as to lead to a sharp edge surface seal. In one non-limiting example the plug and the corresponding seat are tapered and the plug is relatively large in size in comparison to the size of the opening 58 for the discharge of molten metal. Upon reduction of the head height of molten metal the plug is displaced from the seat and the annular area between the tapered surface of the plug and its tapered seat becomes of a size greater than the pouring orifice, the primary pressure drop shifts to the pouring orifice and the plug floats away from the seat.
It should be understood that in all of the embodiments described and/or illustrated herein the bottom pour opening might be centered in the base of the crucible or might be offset from the center of the base. Additionally, it should be further understood that the crucible might be any of a variety of shapes and cross-sections.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the inventions are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.
|
A method of initiating a pour of a liquid alloy comprises the steps of filling an interior of a crucible with a displacement plunger and the liquid alloy until a metal head of the liquid alloy exceeds a critical height. The crucible has a bottom pour opening with a plug inserted therein. The plug is configured to be buoyant within the liquid alloy when the liquid alloy is below the critical height. Pour is initiated by at least partially withdrawing the displacement plunger until the metal head drops below the critical height.
| 1
|
FIELD OF THE INVENTION
[0001] The present invention relates to a process for cladding film sheets with self-adhesive coatings on their backside onto parts that are to be glued, especially car body components in accordance with the preamble of claim 1 .
[0002] The invention furthermore according to claim 10 relates to a novel device for automatically cladding self-adhesive film sheets, especially for executing the process in accordance with the invention.
BACKGROUND OF THE INVENTION
[0003] DE-GM 29907231 describes a self-adhesive sheet of molding. Such sheets are used to line body components in the automotive industry for example, and frequently used for A, B, and/or C-pillars on a car's exterior. There they make an aesthetically attractive and protective decoration of the component's surface. The sheets are blanked out of film webs, particularly strip-like lengthwise, punched in particular, with a shape that has been fit to the component to be glued. Here the film sheet mainly consists of plastic, PVC in particular.
[0004] The sheets must be clad very exactly, positionally accurate and wrinkle-free, which has only been possible manually up to now. But this work demands a large expenditure of time and labor and is consequently associated with relatively high production costs. In addition, the precision depends on the care taken by the respective worker, so that the required repeat accuracy (process control) can only be conditionally achieved.
[0005] U.S. Pat. No. 5,733,410 specifies a device for the application of adhesive labels on flat surfaces of specific articles. This device has a labeling head comprising a convex application surface on which the respective label is fixed by means of vacuum suction. The labeling head is supported at one end by a bearing pin in such a manner that its other end can be pivoted against a spring. Together with the labeling head, the support can be exclusively moved vertically, perpendicular to the horizontally positioned article surface being labeled, by means of a pneumatic cylinder. The result of this is that one side of the adhesive label is first pressed on by a downward motion of the labeling head and then applied flatly by means of the labeling head automatically rotating solely from the vertical motion. Actually, this results in a relative frictional motion of the convex surface of the labeling head on the flat article surface being labeled such that sliding-like creases can occur particularly when applying large labels. This known device might therefore be only suitable for smaller adhesive labels. Also, the vacuum suction causes arching to such an extent in the label that resultant air bubbles are captured. Overall, therefore, accuracy leaves something to be desired with this known device. In addition, it is restricted to an application with horizontally positioned adhesive surfaces.
[0006] DE-A-28 53 033 specifies a device for producing film vehicle identification plates. The sections of film are first taken from a course of double film by means of a drum and then rolled onto a plate, the plate being moved beneath the rotating drum. The sections of film are fixed onto the drum by vacuum. Here, too, there is the disadvantage that, during application, air bubbles can be created in the area of the suction holes in the drum. In addition, here, too, the device is restricted to a horizontal arrangement of the parts (sheet metal parts) being labeled.
SUMMARY OF THE INVENTION
[0007] It is the objective of the present invention to present a process by which the described work operation of gluing film sheets with a positionally accurate labeling application can be carried out economically, with little labor, time and, in particular, irrespective of the spatial orientation of the part being labeled, but still with high accuracy (exact positioning, wrinkle-free). Furthermore, a structurally simple and inexpensive device with high process control shall also be created to execute the process. To do this, the application mechanism is mechanically controlled in a three-dimensional motion (in three coordinates of space) in such a manner according to the invention that a clean, friction-free rolling motion is achieved on the surface being labeled, or over the surface. This involves not only a simple rotating motion of the application mechanism about only a specific pivot during a concurrent linear feed/pressing motion, but much more a special three-dimensionally controlled motion each time about a “virtual” dynamically progressing axis of rotational motion that is always positioned in an approximately tangential point of contact (line of contact) between the component and the convex mounting surface (or the section of film positioned on it) and therefore travels over the component in a progressive rolling motion. In this way, a frictional relative motion between the component and the convex mounting surface in, or on, the surface being labeled is advantageously totally precluded, which assures a smooth, crease-free application of the cut section of film.
[0008] In accordance with the invention, this is first achieved with a process as recited in claim 1 . Accordingly, the film sheet of interest is positioned with its self-adhesive backside opposite the front side, into a defined orientation on a convexly curved mating surface of an application device and then clad, by means of a determinately, spatially, mechanically controlled pressure and rolling motion of the mating surface of the application device, onto the corresponding part to be glued, which is fixed in a defined arrangement relative to the application device. The movement in accordance with the invention of the application device, or of the mating surface with the film sheet precisely pre-positioned upon it, resembles a rocking seesawing motion of a formerly common ink blotter. It is therefore preferably possible to clad the film sheet very precisely and wrinkle-free in an automated process. It is suitable to use a numerically controlled robot for this, so that the cladding is executed with very precise motion control with high repeat accuracy (process control).
[0009] In addition to that, the invention also provides for the fully random spatial orientation of the surface being labeled. This means that the surface need not be positioned horizontally, but, for example, can also be oriented somewhat vertically or randomly otherwise spatially. This represents a particular advantage with regard to the preferred application of the invention in the automotive industry because any body surfaces can be provided with decorative film directly on the assembly line. In addition to that, the independently controllable motion also permits matching to specific surface contours of the component (contour independence).
[0010] A device in accordance with the invention is distinguished by the characteristics of claim 10 . Preferable further developments of the invention are contained in the claims dependent on claims 1 and 10 , respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention will be explained in more detail by examples based on the drawing, wherein a preferred example of a device in accordance with the invention is represented in different states while the process in accordance with the invention is being executed. The individual figures show:
[0012] [0012]FIG. 1 perspective side view of a device in accordance with the invention with a robot-controlled application device,
[0013] [0013]FIG. 2 plan view of a car door to be glued, in the region of a B-pillar for the sake of an example, in the direction of arrow II of FIG. 1,
[0014] [0014]FIG. 3 cross section through the door of plane III-III of FIG. 2,
[0015] [0015]FIG. 4 plan view of the mating surface of the application device together with a film sheet still illustrated separately,
[0016] [0016]FIG. 5 view as in FIG. 4, with the film sheet pre-positioned on the mating surface while a positioning section and a protective layer arranged on the self-adhesive backside (cover foil/silicone paper, or the like) are being removed,
[0017] [0017]FIG. 6 partial view analogous to FIG. 1 while an actual application operation is beginning,
[0018] [0018]FIG. 7 view as in FIG. 6 during the application device's rocking and seesawing movements,
[0019] [0019]FIG. 8 an optional rolling action carried out by an extra pressure roller of the application device,
[0020] [0020]FIG. 9 cross section IX-IX in accordance with FIG. 8 to illustrate the action while a side strip (so-called welt) of the film sheet is turned over,
[0021] [0021]FIG. 10 view similar to FIG. 9 to fold the side strip approximately 180°, and
[0022] [0022]FIG. 11 plan view as in FIG. 2 onto the completely glued door.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] In accordance with FIG. 1, a part 2 (in this example, a car door in the region of a cross-beam, such as the B-pillar) is supposed to be glued with a film sheet 4 (see FIG. 4 in particular). For this, the film sheet 4 is self-adhesive on its backside 4 a, i.e. is coated with a pressure-sensitive bonding emulsion, whereas its opposite front side 4 b forms a decorative surface.
[0024] As is furthermore seen in FIG. 1, a device in accordance with the invention features an application device 6 to automatically clad film sheet 4 onto part 2 with positional precision. A robotic arm 8 preferably guides and precisely controls its movements in three-dimensional space. In practice, the application device 6 thus forms a “hand” of robotic arm 8 . The part 2 to be glued can be fixed in a defined alignment relative to the application device 6 , and appropriate holding means 10 are arranged in a defined arrangement relative to the robotic arm 8 for this purpose, fastened to a mutual machine frame 12 for example.
[0025] The application device 6 features a convexly curved mating surface 14 , which is determinately aligned and fixed to fit the corresponding film sheet 4 . The shape of the mating surface 14 is adapted to the shape of film sheet 4 . In the illustrated example, film sheet 4 is oblong and designed long and rectangular in the widest sense, so that the mating surface 14 likewise has a corresponding, but somewhat larger oblong rectangular shape. Since the mating surface 14 is only designed as curved in the direction of one axis, the surface's longitudinal axis to be particular, but is designed straight perpendicular to that axis (in the transverse direction), the result is a contact rolling or rocker surface like that of a rocker blotter formerly used as an ink blotter. The corresponding film sheet 4 can be fixed onto the mating surface 14 , by vacuum suction in particular, and indeed in an alignment in which its decorative front side 4 b rests on the mating surface 14 and its backside 4 a, coated with self-adhesive, is openly pointed forwards away from mating surface 14 . In accordance with the invention, the application device 6 can be three-dimensionally, mechanically controlled relative to the part 2 to be glued in such a way that film sheet 4 can be clad clean, i.e. friction-free to part 2 by a pressure and rolling motion of the mating surface 14 . This operation is illustrated in FIGS. 6 and 7 in particular.
[0026] Consequently, the rolling motion does not occur only about a specific pivot axis of the application mechanism 6 , but in each case about a “virtual” dynamically progressing axis of rotational motion 15 over the component 2 (see FIG. 6 and 7 ), whereby the progressing axis of rotational motion 15 , during the rolling motion, always coincides with an essentially linear zone of contact resulting between the component 2 and the cut section of film 4 arranged on the convex mounting surface 14 . In this contact zone, the component 2 and the mounting surface 14 , between which is positioned the cut film section 4 , are approximately tangentially adjacent to each other. The result of this motion control of the application mechanism 6 according to invention is that every relative motion and friction resulting thereby is advantageously precluded on the surface being labeled because the application mechanism rolls solely on the component 2 . As a result, the cut section of film 4 is applied very accurately and totally free of creases.
[0027] A programmable control unit, not illustrated in the drawing, is provided for motion control of the robotic arm 8 and application device 6 . We can be dealing with conventional computerized numerical control.
[0028] The means for the vacuum suction already mentioned consist of vacuum suction holes 16 near the mating surface 14 , whereby the suction holes 16 can be connected to an unillustrated vacuum pump by lines 18 . The holes are also arranged over the mating surface 14 with a particular distribution. It is particularly advantageous for the suction holes 16 to be arranged only in the region of the edge strips 20 of film sheet 4 , whereby these edge strips 20 still project beyond the edges of part 2 after the application device 6 has performed the first cladding onto part 2 by means of the pressure and rolling motion in accordance with the invention, i.e. they lie outside the first surface glued. The vacuum suction only occurs in the region of the edge strips 20 , thereby advantageously preventing vaults of the film sheet in the first surface region to be glued. These vaults could otherwise lead to blistering. High precision is therefore achieved. In addition, more suction holes 16 are located in the region of a positioning section 22 of film sheet 4 , which is arranged on the narrow side, whereby this positioning section 22 can be removed (see FIG. 5) after film sheet 4 has been exactly fixed into position. Moreover, alignment means 24 (pin-shaped in particular) are arranged on mating surface 14 in this region, and film sheet 4 can be hung onto them with positioning section 22 for pre-alignment.
[0029] The mating surface 14 of the application device 6 is preferably made of a flexible deformable layer 26 , especially of a silicone cushion or other suitable plastic. This also contributes to a qualitatively superior bonding.
[0030] The application device 6 may additionally feature at least one pressure roller 28 , mounted to rotate freely, preferably with a likewise flexible deformable covering 30 . Two pressure rollers 28 , of different length and width, are fastened to the application device 6 in the illustrated example. They can each be brought into a service position by properly controlled movements of the application device 6 and be guided over film sheet 4 again to press it. The dimensions (diameter, length, and width) of a respective pressure roller 28 are adapted to the respective application. A wider pressure roller 28 for rolling the entire width of film sheet 4 , and a narrower pressure roller 28 for other uses, are provided in the illustrated example. See FIGS. 9 and 10 in particular.
[0031] The process in accordance with the invention will be described in more detail below.
[0032] In accordance with FIGS. 4 and 5, the respective film sheet 4 is first pre-positioned onto the convexly curved mating surface 14 of application device 6 in a defined orientation with its self-adhering backside 4 a opposite its front side 4 b. For this purpose, film sheet 4 can be hung onto the alignment means 14 with the positioning holes of its positioning section 22 . This suspending, or pre-positioning, of the cut section of film 4 can actually also be done manually by a helper. This can preferably be accomplished through a determinately controlled fetching movement of the application device 6 , wherein this device takes one film sheet 4 at a time from a magazine-like feeding station, for example. In this initially loosely hanging state starting with the alignment means 24 , the wider pressure roller 28 can roll over the length of the mating surface 14 to align film sheet 4 more precisely. The actual fixing then occurs, especially by activation of the vacuum suction by means of suction holes 16 , which are preferably arranged on the edges.
[0033] The positioning section 22 is then separated from the actual film sheet 4 in accordance with FIG. 5 and removed. In addition, a protective layer 32 , which had been arranged on the self-adhesive coating in advance, is pulled off and removed, thereby exposing the adhesive coating. Both actions can be executed simultaneously in one operating cycle, manually for example.
[0034] In FIG. 6, the application device 6 is then moved against part 2 in the direction of the arrow 34 and pressed on lightly for the first pressing of film sheet 4 on one side (narrow-edged side). A rocking motion about the axis of swivel motion 15 thereby dynamically shifting in the direction of the arrows 15 a drawn in FIG. 6 and 7 in accordance with the invention corresponding to arrow 36 in FIGS. 6 and 7 follows, so that film sheet 4 is glued on wrinkle-free by a seesawing movement. During this rolling movement, i.e. preferably right after the first contact with the adhesive in accordance with FIG. 6, the vacuum suction is deactivated. This can also occur gradually, while the rolling motion is occurring over the surface. As shown in FIG. 8, an extra rolling of the pressure roller 28 may be executed, at least locally.
[0035] In the special case of coating the region around a car pillar, it is often required that the sheet is wrapped around at least one web-like edge section 40 of car part 2 (so-called welt). In this case, pressure roller 28 rolls over edge section 40 at least once in accordance with FIGS. 9 and 10 with a determinately controlled movement in accordance with the invention, folding the corresponding remaining edge strip 20 of film sheet 4 . In order to achieve a fold of approximately 180°, it is appropriate to roll over it at least twice. The relatively flexible deformability of the covering 30 of pressure roller 28 favors the wrapping. A wrinkle-free bonding can thereby also be achieved in this region.
[0036] The invention is not limited to the illustrated and described examples, but includes all embodiments that work similarly to the spirit of the invention. For example, there is an advantageous alternative to the pre-alignment of film sheet 4 on mating surface 14 that was described. It consists of the formation of alignment means on the mating surface 14 in the shape of at least punctiform bumps for resting film sheet 4 on the edges in such a manner that the sheet can be determinately positioned on the mating surface 14 at least by a three-point arrangement. The positioning section 22 and its associated alignment means 24 described above will thereby become superfluous. The operating cycle e.g., manual of separating and removing the positioning section 22 will also drop away. It is only necessary to put down the actual film sheet 4 to be glued and arrange it on the elevated alignment means. This is preferably executed manually, which also applies to the subsequent removal of the protective layer 32 after the vacuum fixation. The alignment means, which are arranged on the mating surface 14 as relatively flat or low bumps, can't get out of the way when sheet 4 is pressed because of the elasticity and flexibility of the elastic layer 26 , so they won't interfere with the pressing. It is furthermore possible to press on the film section 4 at a given point of its total surface first, i.e., the starting point for positioning (top, bottom, middle . . . ) on the component being labeled can be independently selected by the independently programmable motion control. As for the rest, the invention is moreover not limited to the combination of characteristics defined in claims 1 and 7 , but can also be defined by any desired other combination of particular characteristics in all of the individually disclosed characteristics as a whole. This means in principle, that practically any individual characteristic of claim 1 or 7 can be deleted and replaced by at least one individual characteristic disclosed at another place in the application. To this extent, the claims are to be understood merely as a first attempt to formulate an invention.
|
The invention relates to a process for positionally precise cladding of film sheets ( 4 ), with self-adhesive coatings on their backside ( 4 a ), onto parts ( 2 ) to be glued, especially car body components. The respective film sheet ( 4 ), in a convexly curved state of its self-adhesive backside, is pre-positioned into a defined orientation and then clad, by means of a determinately controlled pressure and rolling motion, onto the respective part ( 2 ) to be glued, which is fixed in a defined arrangement.
| 8
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a system and method for removing hydrogen sulfide from carbon dioxide, methane and other components of natural gas streams being processed into a sales gas stream. The system and method of the invention are particularly suitable to separate carbon dioxide and hydrogen sulfide when the Stinson Process is utilized for removing high concentrations of carbon dioxide and hydrogen sulfide from natural gas streams containing nitrogen.
[0003] 2. Description of Related Art
[0004] Hydrogen sulfide and carbon dioxide contamination are frequently encountered problems in the production of natural gas. Transporting pipelines typically do not accept natural gas containing more than about 4% CO 2 and 4 ppm hydrogen sulfide. Hydrogen sulfide is particularly problematic because it is extremely toxic to humans and is corrosive in nature. Allowing hydrogen sulfide to remain in process streams can be harmful to piping and other equipment. As such, it is desirable to remove H 2 S from the produced gas early in the processing.
[0005] Known methods of removing H 2 S and CO 2 from natural gas streams include chemical solvents and physical solvents. These technologies have been well tested in the natural gas industry and the strengths and weaknesses of various chemical components used in these processes are well known to those in the industry. One such physical solvent that is well established in the industry is Selexol from Dow Chemical. With a typical Selexol process, the feed gas contacts the Selexol in a first absorber, where the majority of the CO 2 and H 2 S in the feed stream are removed into the solvent. The CO 2 and H 2 S are then separated through one or more reduced pressure separators and a stripper to produce a CO 2 and H 2 S rich “acid gas” vapor stream and a “Lean” Selexol stream to be recycled back to the inlet absorber where it removes more CO 2 and H 2 S from incoming gas. Utilization of conventional Selexol technology is used where the CO 2 concentrations are generally in the 10 to 20 percent range and are used in preference to chemical processes based on the comparative installation cost and the cost of operation.
[0006] Another known method for removing both CO 2 and H 2 S from natural gas is known as the Stinson Process, as described in U.S. Pat. No. 7,883,569 and the patents related thereto. The Stinson Process takes a dehydrated feed stream containing around 70% CO 2 , 20% CH 4 , 7% N 2 , and 3.5% H 2 S and produces a processed gas stream containing around 3% N 2 , 97% CH 4 , and 0.03% H 2 S and a liquid waste stream containing around 94% CO 2 and 5% H 2 S. The CO 2 and H 2 S are removed from the feed stream using a fractionating column, with the bottom stream containing primarily CO 2 and some H 2 S and an overhead stream containing 31% CO 2 and less than 2% H 2 S. The overhead stream from the fractionating column is then processed using a methanol absorption tower to separate additional CO 2 and H 2 S and produce an intermediate processed gas stream (containing around 69% methane) as the overhead stream from the absorption tower, which is then processed through a separator to remove nitrogen and helium, resulting in a processed gas stream containing around 97% CH 4 and around 0.03% H 2 S. This processed gas stream is then typically passed through a molecular sieve to scrub the 300 ppm H 2 S down to an acceptable pipeline level of less than 4 ppm for sales gas. The methanol is then recovered using a flash chamber and a methanol stripper tower, with the recovered methanol being recycled back to the methanol absorption tower. The overhead streams from the flash chamber and methanol stripper contain CO 2 , CH 4 , and H 2 S and are recycled back to feed the fractionating column. The liquid waste stream from the fractionating column, which contains around 94% CO 2 and 5% H 2 S may be injected into an underground well, avoiding some of the environmental concerns associated with releasing CO 2 and H 2 S to the atmosphere.
SUMMARY OF THE INVENTION
[0007] The system and method disclosed herein facilitate the economically efficient and selective removal of H 2 S from a feed gas stream containing methane and CO 2 using a solvent. The system and method of the invention are particularly suitable for integrated use in connection with the Stinson Process for removing CO 2 , wherein the solvent used to remove the H 2 S is different from the solvent used to remove CO 2 and the majority of the H 2 S is removed upstream from the CO 2 removal. Natural gas processing using the prior art Stinson Process, with around 3.5% H 2 S in the feed stream, generally results in a sales gas (hydrocarbon) stream containing no CO 2 (or less than 4 ppm CO 2 ) and around 4 ppm of H 2 S, and a CO 2 waste stream containing around 47,000 ppm H 2 S. The methanol stripping in the Stinson Process will reduce the level of H 2 S from 3.5% in the feed to around 0.03% (300 ppm), which is further reduced to 4 ppm or less after passing through a molecular sieve to produce an acceptable sales gas. While the amount of H 2 S in the sales gas stream may be within pipeline specifications, the amount in the waste stream limits the ability to use the CO 2 waste stream for flooding operations. Typically, the H 2 S specification for CO 2 flood streams is less than 100 ppm. Removing the majority of the H 2 S upstream of the Stinson Process according to the invention increases the overall process efficiencies, including a reduction in operating costs through fuel savings, while allowing production of a processed CO 2 stream from the Stinson Process that is well within specifications for allowing use of that stream in flooding operations. The processed CO 2 stream can also be delivered to the pipeline as a liquid stream, which has significant cost savings over injecting as a vapor. By reducing the H 2 S level in the Stinson Process feed to a preferable level less than 50 ppm, it may be unnecessary to use a molecular sieve after the Stinson Process to achieve a sales gas stream with an acceptable H 2 S level, which may offset some of the capital costs associated with the invention and saves on operating costs. Additionally, the use of two different solvents, a first solvent to remove H 2 S and a second solvent to remove CO 2 , where the solubility of H 2 S relative to CO 2 in the first solvent is greater than the relative solubility in the second solvent, further increases the efficiencies of the overall process.
[0008] Through the use of the invention, the 3.5% (35,000 ppm) H 2 S typically found in the Stinson Process feed stream is substantially reduced. According to the invention, the processed gas stream that feeds the Stinson Process fractionating column preferably contains less than 50 ppm (0.005%) of H 2 S, but may contain up to 150 ppm or more H 2 S depending on the amount of H 2 S in the gas stream feeding the system of the invention, although the amount of H 2 S is still significantly less than the 35,000 ppm in a typical Stinson feed stream. Consequently, only trace amounts of H 2 S are present in the final sales gas (hydrocarbon) stream and in the processed CO 2 stream using the H 2 S removal methods according to the invention integrated with the Stinson Process. Additionally, the concentrated CO 2 waste stream in the typical Stinson Process has around 94% CO 2 and 5% H 2 S, which is too much H 2 S to allow use of the CO 2 in flooding operations, but not enough H 2 S to allow for recovery of sulfur—making it truly a waste stream. By first reducing the H 2 S level in the Stinson feed according to the invention, the processed CO 2 stream produced from the Stinson Process fractionating column has sufficiently low levels of H 2 S to permit use in flooding operations. Additionally, the acid gas stream of the present invention contains 0.5%-50% (or more) H 2 S, but preferably contains at least 30% H 2 S. The amount of H 2 S in the acid gas stream will depend on the amount of H 2 S in the stream that feeds the system of the invention. The preferred higher concentration levels for H 2 S in the acid gas stream of the present invention make that stream suitable for feeding a Claus Process to recover sulfur from the H 2 S, if desired. Thus the use of the invention integrated with the Stinson Process allows reuse of what would otherwise be waste streams with prior art processes. Alternatively, the volume of the acid gas stream according to the invention is relatively smaller than a traditional Stinson Process acid gas (CO 2 waste) stream, making it easier to dispose of the H 2 S if further processing is not desired.
[0009] According to one embodiment of the invention, a system and method are disclosed for strategically integrating an H 2 S removal system into a typical Stinson Process operation. The feed stream that normally feeds the fractionating column (after passing through dehydration beds and a heat exchanger) in the Stinson Process is first processed through the H 2 S removal system of the present invention. After preferably being dehydrated, the feed stream passes through an absorber, where H 2 S is selectively absorbed by the use of DEPG (dimethyl ether polyethylene glycol, available from Dow Chemical under the trademark SELEXOL®) or a similar solvent. Most preferably, the removal operation is anhydrous. The vapor stream exiting the absorber is the Stinson Process feed stream that preferably feeds directly to the fractionating column in the Stinson Process and then being processed as disclosed in U.S. Pat. No. 7,883,569, which is incorporated herein by reference. The liquid stream exiting the absorber then feeds a series of separators and a stripper to recover the DEPG solvent and produce an acid gas stream preferably containing around 50% CO 2 and around 30-40% H 2 S.
[0010] According to another embodiment of the invention, nitrogen is fed to the stripper to enhance separation of the DEPG from the CO 2 and H 2 S. Preferably, the nitrogen is supplied from an onsite Nitech™ NRU (such as that described in U.S. Pat. No. 5,141,544), to provide enhanced efficiencies; but other sources of nitrogen may be used. Typically, water or steam is used to regenerate the DEPG. The addition of nitrogen to the stripper enhances the recovery of the DEPG when operating in an anhydrous mode, according to a preferred embodiment of the invention. Additionally, an anhydrous operation results in further cost savings, since lower cost metals may be used in equipment fabrication.
[0011] There are several advantages to the system and method disclosed herein not previously achievable by those of ordinary skill in the art using existing technologies. These advantages include, for example, the system and method allow for the CO 2 stream produced through the Stinson Process to be within pipeline specifications for use in flooding operations, rather than be treated as a waste stream requiring disposal. The system and method also allow for removal of the corrosive H 2 S prior to processing in the Stinson Process and results in an acid gas stream having sufficiently high concentration of H 2 S to allow further processing for recovery of sulfur, if desired. By integration with common utilities utilized by the Stinson Process, the cost of new equipment is reduced. Because the H 2 S is highly soluble in the methanol used in the Stinson Process, the removal of the H 2 S prior to the Stinson Process will enhance the removal of CO 2 in the Stinson Process. Additionally, the system and method of the invention require low regeneration of heat, using only 30%-50% of the energy required for conventional technologies to separate out H 2 S. The system and method of the invention are particularly well suited for feed streams containing 20% or more CO 2 .
[0012] Although the present system and method has the disadvantage of higher capital costs associated with additional equipment for the H 2 S removal, the costs of such are sufficiently offset by the savings in having a usable Stinson Process CO 2 stream and savings in operating costs achieved by strategically placing the H 2 S removal upstream of the Stinson Process to take advantage of inter-operational efficiencies.
[0013] Those of ordinary skill in the art will appreciate upon reading this disclosure that references to separation of H 2 S, CO 2 , and methane used herein refer to processing natural gas feed streams containing additional components to produce various multi-component product streams containing large amounts of the particular desired component, but not necessarily pure streams of any particular component. Additionally, those of ordinary skill in the art will understand that streams that are described herein as liquid or vapor streams are not necessarily purely in a liquid or gaseous state, but may be primarily present as a liquid or gas. Those of ordinary skill in the art will also appreciate upon reading this disclosure that additional processing sections for removing various components or contaminants that are present in the feed stream or intermediate streams, can also be included in the system and method of the invention, depending upon factors such as, for example, the origin and intended disposition of the product streams and the amounts of such other gases, impurities or contaminants as are present in the streams.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The system and method of the invention are further described and explained in relation to the following drawings wherein:
[0015] FIG. 1 is a simplified process flow diagram illustrating principal processing stages of an embodiment of a system and method for removing H 2 S;
[0016] FIG. 2 is a more detailed process flow diagram illustrating the processing stages of a preferred embodiment of a system and method for removing H 2 S.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] FIG. 1 depicts the basic processing stages of the system and method according to a preferred embodiment of the invention. The system 10 comprises processing equipment that is inserted into typical natural gas processing operations upstream of the fractionating column used in the Stinson Process. System 10 of the invention includes an absorber 20 , a scrubber 30 , a primary separator 60 , a secondary separator 90 , and a stripper 100 . System 10 also includes a DPEG processing block 130 , which includes pumps and heat exchangers as more fully described in relation to FIG. 2 . A gas feed stream, comprising methane, hydrogen sulfide, and carbon dioxide is preferably dehydrated using known methods, such as a standard molecular sieve style water removal process, prior to entering system 10 as feed stream 12 . Feed stream 12 contains methane, at least 20% CO 2 , and at least 0.5% H 2 S. Preferably, feed stream 12 contains 15%-25% methane, at least 50% CO 2 , and most preferably 60%-80% CO 2 , 0.5%-20% H 2 S, and most preferably 3%-6% H 2 S, and 5%-15% nitrogen, although other feed stream compositions may be used with the invention. Feed stream 12 is fed into absorber 20 . A DPEG feed stream 14 is also fed to absorber 20 to facilitate removal of H 2 S from the gas feed stream 12 . Overhead stream 16 , preferably comprising around 50 ppm H 2 S or less exits absorber 20 and is the feed stream to the fractionating column of the Stinson Process. Because feed stream 12 was preferably dehydrated prior to feeding absorber 20 , it is not necessary to dehydrate overhead stream 16 prior to feeding the Stinson Process. It may be desirable to pass overhead stream 16 through a heat exchanger prior to feeding the fractionating column of the Stinson Process or stream 16 may be fed directly to the fractionating column.
[0018] Bottom stream 26 is combined with a first carbon dioxide recycle stream 84 to feed scrubber 30 . Carbon dioxide recycle stream 84 comprises primarily CO 2 , with some H 2 S and small amounts of other compounds. Vapor stream 54 is recycled from the scrubber 30 back to a bottom level of the absorber 20 . Liquid stream 32 exits scrubber 30 and feeds primary separator 60 . Carbon dioxide recycle vapor stream 84 and liquid stream 62 exit primary separator 60 . Liquid stream 62 feeds secondary separator 90 . Vapor stream 92 and liquid stream 106 exit secondary separator 90 to feed stripper 100 . A nitrogen feed stream 160 may also be fed to a bottom level of stripper 100 , if desired. Stripper 100 purifies the DPEG from the feed streams to recycle it back to the DPEG processing block 130 via stream 118 . Acid gas stream 126 , preferably containing 35%-55% carbon dioxide, 5%-15% nitrogen, and 30%-50% hydrogen sulfide, exits stripper 100 as the overhead stream and may either be disposed of or may be feed to a Claus process to recover sulfur, if desired.
[0019] A preferred embodiment of system 10 is depicted in greater detail in FIG. 2 . Referring to FIG. 2 , a 200 MMSCFD feed stream 12 containing approximately 19.5% methane, 7% nitrogen, 3.7% H 2 S, and 69.1% CO 2 at 79.9° F. and 671.9 psia feeds a middle stage of absorber 20 . The water content in stream 12 is extremely low, and most preferably zero, as it has first been dehydrated by means of a molecular sieve unit according to a preferred embodiment of the invention. Absorber 20 is also fed at an upper stage by a first solvent feed stream 14 and at a lower stage by a recycle stream 54 . A Stinson Process feed stream 16 exits as the overhead stream from absorber 20 . Bottoms stream 22 exits the bottom of absorber.
[0020] Stinson Process feed stream 16 comprises approximately 21.5% methane, 7.7% nitrogen, 0.002% H 2 S, and 70% CO 2 at 95.4° F. and 670.1 psia. Stinson Process feed stream 16 preferably contains between 60%-70% of the total amount of CO 2 fed into absorber 20 and at least 80% of the CO 2 in feed stream 12 . After exiting absorber 20 , Stinson Process feed stream 16 is then preferably fed to the Stinson Process. As disclosed in U.S. Pat. No. 7,833,569, the Stinson Process feed stream (stream 16 according to the present invention), passes through a heat exchanger before entering a fractionating column. Typically, the Stinson Process feed stream is also dehydrated prior to entering the fractionating column. Because the feed stream 12 is dehydrated prior to entering absorber 20 according to a preferred embodiment of the invention, it is not necessary to dehydrate Stinson Process feed stream 16 prior to feeding the Stinson Process fractionating column. The vapor stream from the fractionating column and a second solvent feed stream (preferably methanol) feed an absorption tower, with a processed gas stream exiting as the vapor stream from the absorption tower. This vapor stream then becomes the final sales gas stream after passing through a molecular sieve in a typical Stinson Process, although it is not necessary to use a molecular sieve to achieve acceptable levels of H 2 S in the sales gas stream when the Stinson feed stream is processed according to the invention. The liquid stream from the absorption tower then feeds a flash chamber, with the liquid stream from the flash chamber feeding a methanol stripper. The vapor streams from the flash chamber and stripper are carbon dioxide recycle streams, comprising primarily carbon dioxide and some methane and hydrogen sulfide along with trace amounts of other compounds that feed back into the fractionating column. The liquid stream from the stripper is a solvent recycle stream that feeds back into the solvent feed stream. The liquid stream from the fractionating column in the typical Stinson Process is a CO 2 waste stream that is injected into an underground well. However, the high CO 2 and low H 2 S concentrations in feed stream 16 according to the invention result in the processed CO 2 stream in the Stinson Process (stream no. 60 in the Stinson '569 patent) having an H 2 S concentration well within pipeline specification for use in CO 2 flooding operations, so that the CO 2 stream may be reused and does not require immediate disposal. Most preferably, the Stinson Process fractionating column bottoms stream comprises at least 90% CO 2 and less than 4 ppm H 2 S when the fractionating column is fed with stream 16 according to the invention. The Stinson Process system, and preferred parameters for operation, are more fully described in the '569 patent.
[0021] Referring again to FIG. 2 , DEPG (such as Selexol®) is a preferred solvent for use in solvent feed stream 14 according to the invention because of its higher affinity for H 2 S over CO 2 . The solubility of H 2 S in DEPG is around nine times greater than that of CO 2 , allowing the bulk of the CO 2 in feed stream 12 to pass through absorber 20 and exit as Stinson Process feed stream 16 . Preferably, stream 16 contains more than 80% of the CO 2 present in feed stream 12 and more than 60% of the total CO 2 fed to absorber 20 by feed stream 12 and recycle stream 54 . Although DEPG is a preferred solvent, other solvents may be used within the scope of the invention. Additionally, the preferred solvent for use in the Stinson Process is methanol, but other solvents may be used with that process according to the invention. Most preferably, the first solvent used in absorber 20 is different from the second solvent used in the Stinson Process, with the solubility of H 2 S relative to CO 2 in the second solvent being less than the relative solubility in the first solvent. System 10 is also preferably operated in an anhydrous mode, with no water being added to the first solvent feed or added to stripper 100 (discussed below).
[0022] Bottom stream 22 exits the bottom of absorber 20 , containing approximately 0.007% methane, negligible nitrogen, 36.6% DEPG, 7.9% H 2 S, and 55.4% CO 2 at 110.1° F. and 672.1 psia. Bottom stream 22 passes through liquid level control valve 24 , exiting the valve as stream 26 at 86° F. and 310 psia. The liquid entering valve 24 is capable of cooling by the well-known Joule-Thomson effect. Stream 26 is mixed with stream 84 in mixer 86 , exiting as combined stream 28 containing approximately 29.95% DEPG, 7.8% H 2 S, and 62.1% CO 2 . Combined stream 28 feeds scrubber 30 , where the majority of the CO 2 is separated for recycling back to absorber 20 . Overhead vapor stream 42 and bottom liquid stream 32 exit scrubber 30 containing approximately 60.5% and 39.5%, respectively, of the CO 2 fed to scrubber 30 . Overhead stream 42 also contains approximately 4% H 2 S and a negligible amount of DEPG, while bottom stream 32 contains approximately 10.3% H 2 S and 49.3% DEPG. Overhead stream 42 is compressed by compressor 44 , exiting as stream 46 at 236.9° F. and 700 psia. Compressor 44 receives energy, designated as energy stream Q-10. Stream 46 then passes through heat exchanger 48 , exiting as stream 54 cooled to at 110° F. Heat exchanger 48 releases heat, designated by energy stream Q-12. Stream 54 , a carbon dioxide recycle stream, is fed into a bottom stage of absorber 20 . Stream 54 contains approximately 95.9% CO 2 and 4% H 2 S at 695 psia.
[0023] Bottom stream 32 exits scrubber 30 and passes through liquid level valve 34 , exiting as stream 36 having the pressure reduced from 305 psia to 120 psia and a drop in temperature of approximately 20° F. Stream 36 passes through heat exchanger 38 , which receives energy (designated as energy stream Q-14) released from heat exchanger 148 , and exits as stream 40 having been warmed from 66.5° F. to 93.4° F. Stream 40 feeds primary flash gas separator 60 , with vapor stream 72 and liquid stream 62 exiting the separator 60 . Vapor stream 72 , another carbon dioxide recycle stream containing approximately 92.6% CO 2 , and 7.2% H 2 S at 93.4° F. and 115 psia passes through compressor 74 exiting as stream 76 at 266.6° F. and 315 psia. Compressor 74 is supplied with energy designated as energy stream Q-20. Stream 76 passes through heat exchanger 78 where it is cooled to 110° F. as stream 84 . Heat exchanger 78 releases heat energy designated as energy stream Q-30. Stream 84 is then mixed with stream 26 in mixer 86 to feed scrubber 30 as combined stream 28 .
[0024] Liquid stream 62 , containing approximately 18.1% CO 2 , 11.6% H 2 S, and 70.2% DEPG at 93.4° F. and 115 psia, passes through level control valve 68 , exiting the valve as partially vaporized stream 70 with a pressure drop of approximately 48 psi. Stream 70 feeds secondary flash gas separator 90 , exiting as vapor stream 92 and liquid stream 106 , both streams at 87.4° F. and 65 psia. Vapor stream 92 , containing 89.7% CO 2 and 10.1% H 2 S feeds an upper stage of stripper 100 . Liquid stream 106 , containing 11.6% CO2, 11.7% H2S and 76.6% DEPG is split by splitter 104 into streams 94 and 102 . Stream 102 feeds stripper 100 . Stream 94 passes through heat exchanger 96 , exiting as stream 98 having been heated to 288.2° F. and partially vaporized. Stream 98 feeds an intermediate stage of stripper 100 . Optionally, a nitrogen feed stream 160 , containing near 100% N 2 at 80° F. and 25 psia, may also feed a lower stage of stripper 100 . The addition of nitrogen feed stream 160 to stripper may result in increased recovery of the DEPG solvent. In the simulation example described herein, stream 160 has a flow rate of 2.5 MMSCFD.
[0025] Stripper 100 strips the DEPG from the other components so that the DEPG may be recycled back to absorber 20 . Bottom liquid stream 108 , containing 99.9% DEPG at 297.8° F. and 17.5 psia, exits stripper 100 and is pumped by pump 110 , exiting as stream 112 at 65 psia. Pump 110 receives energy designated as energy stream Q-24. Stream 112 passes through heat exchanger 96 for heat transfer with stream 94 . Stream 112 exits heat exchanger 96 as stream 118 at a temperature of 105.6° F. Stream 118 enters a makeup block 134 where additional DEPG may be added or bled off via streams 132 or 136 . Stream 138 exits the makeup block 134 containing approximately 99.9% DEPG, no water, and small amounts of nitrogen and hydrogen sulfide at around 105.6° F. and 60 psia. Stream 138 is pumped through pump 140 , supplied by energy designated as energy stream Q-22. Stream 142 exits pump 140 with the pressure increased to 715 psia. Stream 142 passes through heat exchanger 144 and exits as stream 146 cooled to 110° F. Stream 146 then passes through second and third heat exchangers, 148 and 152 , ultimately exiting as DEPG feed stream 14 having a temperature of 40° F. and a pressure of 700 psia. Stream 14 feeds an upper stage of absorber 20 . Heat exchangers 144 , 148 , and 152 release heat energy designated as energy streams Q-26, Q-14, and Q-28, respectively.
[0026] Overhead vapor (or acid gas) stream 126 exits stripper 100 containing 53.9% CO 2 , 34.4% H 2 S and 11.5% N 2 at a temperature of 80.7° F. and a pressure of 15.5 psia. Acid gas stream 126 may be properly disposed of or may feed other processing equipment to recover sulfur.
Example
[0027] The flow rates, temperatures and pressures of various simulation flow streams referred to in connection with the discussion of the system and method of the invention in relation to FIG. 2 for a feed gas stream flow rate of approximately 200 MMSCFD and containing 7% nitrogen, 19.5% methane, 69.1% CO 2 , and 3.7% H 2 S appear in Table 1 below. The values for the energy streams referred to in connection with the discussions of the system and method of the invention in relation to FIG. 2 appear in Table 2 below. The values discussed herein and in the tables below are approximate values.
[0000]
TABLE 1
FLOW STREAM PROPERTIES
Stream
Flow
Ref.
%
%
%
Rate
Temp.
Press.
No.
% N 2
CO2
H2S
% CH 4
DEPG
(lbmol/h)
(deg. F)
(psia)
12
7
69.1
3.7
19.5
0
21956
79.9
671.9
14
0.098
0
0.012
0
99.89
4889.3
40
700
16
7.7
70
0.002
21.5
neg
19889.1
95.4
670.1
22
neg
55.4
7.9
0.007
36.6
13350.3
110.1
672.1
26
neg
55.4
7.9
0.007
36.6
13350.3
86
310
28
neg
62.1
7.8
0.006
30
16306.5
87
310
32
neg
40.3
10.3
0.0005
49.3
9910.3
86.6
305
36
neg
40.3
10.3
0.0005
49.3
9910.3
66.5
120
40
neg
40.3
10.3
0.0005
49.3
9910.3
93.4
115
42
neg
95.9
3.98
0.014
neg
6396.2
86.6
305
46
neg
95.9
3.98
0.014
neg
6396.2
236.9
700
54
neg
95.9
3.98
0.014
neg
6396.2
110
695
62
neg
18.1
11.6
neg
70.2
6954.6
93.4
115
70
neg
18.1
11.6
neg
70.2
6954.6
87.7
67
72
neg
92.6
7.2
0.0017
neg
2955.7
93.4
115
76
neg
92.6
7.2
0.0017
neg
2955.7
266.6
315
84
neg
92.6
7.2
0.0017
neg
2955.7
110
310
92
neg
89.7
10.1
0.0003
neg
582.1
87.4
65
94
neg
11.6
11.7
neg
76.6
5735.3
87.4
65
98
neg
11.6
11.7
neg
76.6
5735.3
288.2
60
102
neg
11.6
11.7
neg
76.6
637.3
87.4
65
106
neg
11.6
11.7
neg
76.6
6372.5
87.4
65
108
0.098
neg
0.017
0
99.88
4889.6
297.8
17.5
112
0.098
neg
0.017
0
99.88
4889.6
298.2
65
118
0.098
neg
0.017
0
99.88
4889.6
105.6
60
126
11.5
53.9
34.4
neg
0.0001
2339.6
80.7
15.5
132
0
0
0
0
100
0
100
115
136
0.098
neg
0.017
0
99.88
0.029
105.6
60
138
0.098
neg
0.017
0
99.88
4889.5
105.6
60
142
0.098
0
0.012
0
99.88
4889.3
110.5
715
146
0.098
0
0.012
0
99.88
4889.3
110
710
150
0.098
0
0.012
0
99.88
4889.3
72.5
705
160
100
0
0
0
0
274.5
80
25
[0000]
TABLE 2
ENERGY STREAM REPORT
Energy
Stream
Reference
Energy Rate
Power
Numeral
(MMBtu/h)
(hp)
From
To
Q-10
3027.2
—
Compressor
44
Q-12
9.78
Heat
—
Exchanger
48
Q-14
25.34
Heat
Heat
Exchanger
Exchanger
148
38
Q-18
25
9825.4
—
Stripper 100
Q-20
1768.2
—
Compressor
74
Q-22
1587.3
—
Pump 140
Q-24
126.5
—
Pump 110
Q-26
0.33
Heat
—
Exchanger
144
Q-28
21.1
Heat
—
Exchanger
152
Q-30
4.74
Heat
—
Exchanger
78
[0028] Those of ordinary skill in the art will appreciate upon reading this disclosure that the values discussed above are based on the particular parameters and composition of the feed stream in the Example, and that the values can differ depending upon differences in operating conditions and upon the parameters and composition of the feed stream 12 . Those of ordinary skill in the art will also appreciate upon reading the disclosure in light of the accompanying drawings that alterations and modifications of the invention may be made and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventor is legally entitled.
|
A system and method for efficiently removing hydrogen sulfide from a natural gas feed stream to produce a Stinson Process feed stream and an acid gas stream. A first solvent separates the majority of the carbon dioxide and hydrocarbons from the hydrogen sulfide in the natural gas feed to produce the Stinson feed stream. By removing the majority of the hydrogen sulfide prior to feeding the Stinson Process, a carbon dioxide stream suitable for use in flooding operations may be produced with the Stinson Process. The system and method also increase the concentration of hydrogen sulfide in the acid gas stream, making it suitable for sulfur recovery operations. The system and method are particularly suitable for natural gas feed streams containing 0.5%-20% hydrogen sulfide and at least 20% carbon dioxide. Operation in an anhydrous mode with the addition of nitrogen aids in solvent recovery for recycling.
| 2
|
PRIORITY CLAIM
This patent application claims priority to U.S. Provisional Patent Application No. 61/499,185, titled “FIXED (AND SELECTIVELY FIXED) BYPASS PUMPLESS COMBINATION INSTANTANEOUS/STORAGE WATER HEATER SYSTEM,” filed Jun. 21, 2011.
BACKGROUND OF THE INVENTION
The present invention generally relates to liquid heating apparatus and, in representatively illustrated embodiments thereof, more particularly provides a specially designed, pumpless combination instantaneous/storage water heater system.
The on-demand supply of hot water to plumbing fixtures such as sinks, dishwashers, bathtubs and the like has for years been achieved using fuel-fired or electric water heaters in which a relatively large water storage tank is provided with a fuel-fired burner or one or more electric heating elements controlled to maintain pressurized, tank-stored water at a selectively variable delivery temperature—typically around 120 degrees Fahrenheit. Pressurized cold water from a source is piped to the tank to replenish hot water drawn for supply to one or more plumbing fixtures operatively connected to the water heater.
Another conventional way of providing an on-demand supply of hot water to various plumbing fixtures is to use a tankless or “instantaneous” water heater in which water is flowed through a high heat input heat exchanger, without appreciable water storage capacity, so as to provide only as much hot water as needed by the open fixture(s). Where higher hot water flow rates than the instantaneous water heater can provide at the desired heated temperature are required, it has been conventional practice to connect a storage tank to the instantaneous water heater, in series, to augment the hot water delivery capability of the instantaneous water heater with pre-heated storage tank water.
According to another conventional practice, a hot water recirculating loop with a circulating pump therein is operatively coupled to one or both of the instantaneous heater and storage tank to provide even faster delivery of hot water to the served fixtures. Despite the overall hot water production and delivery improvements provided by these conventional instantaneous/tank type water heater combinations, they present several well-known problems, limitations and disadvantages.
For example, the necessity of providing a pump and the pump's necessary controls undesirably builds in additional cost and complexity to the overall hot water supply system.
It would thus be desirable to provide an improved combination instantaneous/tank type water heater system in which the attendant complexity and cost, of pumps, mixing valves and controls was eliminated or minimized.
SUMMARY OF THE INVENTION
In carrying out principles of the present invention, in accordance with representatively illustrated embodiments thereof, specially designed, representatively pumpless fluid heating apparatus is provided which comprises an instantaneous fluid heater, a fluid storage vessel, and flow circuitry, interconnected between the instantaneous fluid heater and the fluid storage vessel. Via the flow circuitry an incoming fluid may be sequentially flowed through the instantaneous fluid heater and the fluid storage vessel or through a fixed (or selectively fixed) bypass to mix with the heated water exiting the instantaneous heater for delivery to the storage heater for discharge from the apparatus as heated fluid.
The flow circuitry, which is representatively piping interconnecting the instantaneous fluid heater in series with the fluid storage vessel, has incorporated therein (1) an incoming fluid bypass structure, representatively a bypass pipe, operable to cause a fixed portion of the incoming fluid to bypass the instantaneous fluid heater, and (2) an orifice connected in series with said incoming fluid bypass pipe and operable to blend a fixed amount of the bypassed fluid and heated fluid exiting said instantaneous fluid heater to maximize the temperature of heated fluid entering the fluid storage vessel while minimizing the pressure loss through the entire system.
The flow circuitry may incorporate therein instead of the orifice, a mixing valve, operable to receive heated fluid exiting the instantaneous fluid heater and unheated fluid through the bypass pipe to deliver to the fluid storage vessel at a fixed temperature.
The flow circuitry may further incorporate therein instead of the orifice, a solenoid valve, operable to control whether unheated fluid will pass through the bypass pipe and mix with the water exiting the instantaneous fluid heater before entering the fluid storage vessel. The opening and closing of said solenoid valve can be controlled by (1) a thermostatically controlled electrical switching device placed in a position to measure the temperature of the fluid entering the fluid storage vessel, (2) an electrical relay triggered by the signal of a flow sensor or flow switch that is internal to the instantaneous fluid heater, or (3) a flow switch in line previous to the bypass pipe.
Illustratively, the fluid heating apparatus is a water heating apparatus, with the instantaneous fluid heater being a fuel-fired instantaneous type water heater, and the fluid storage vessel being the water storage vessel being the tank portion of a storage type water heater having an electrical heating section used to selectively add heat to water disposed within the tank. However, the system described herein is not limited to water heater heating and may be advantageously employed with a variety of other types of fluids to be heated.
Preferably, the combination instantaneous/storage type fluid heating apparatus of the present invention is of a pumpless construction. However, if desired, a pumped fluid recirculation system could be suitably incorporated into the apparatus without departing from principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a specially designed pumpless, combination instantaneous/storage water heating system embodying principles of the present invention.
FIG. 2 is a schematic diagram of an alternate embodiment of the FIG. 1 system.
FIG. 3 is a schematic diagram of an alternate embodiment of the FIG. 1 system.
FIG. 4 is a schematic diagram of an alternate embodiment of the FIG. 1 system.
FIG. 5 is a schematic diagram of an alternate embodiment of the FIG. 1 system.
DETAILED DESCRIPTION
Schematically depicted in FIG. 1 is a pumpless water heater heating system 10 that embodies principles of the present invention and includes an instantaneous gas water heater (IGWH) 12 having a burner section 14 supplied with gaseous fuel via a gas supply line 16 , and a storage type water heater (SWH) 18 having a water storage tank 20 with electric heating elements 22 extending into the interior of tank 20 . IGWH 12 has a water inlet 24 , and a water outlet 26 , and tank 20 has a water inlet 28 and a water outlet 30 .
A water line 34 is interconnected between the IGWH inlet 24 and the tank inlet 28 , and a water line 38 is interconnected between the IGWH outlet 26 and the tank inlet 28 and extends from the tank inlet 28 downwardly through the interior of the tank 20 to a bottom portion thereof. Valve 36 is operatively connected as shown in the water line 34 . Valve 36 is a bypass valve controllable to allow a selectively variable flow or an orifice to allow a fixed amount of incoming cold water therethrough via the line 34 in the direction of the arrows in line 34 . A cold water inlet line 32 (through which incoming cold water is flowed to the system) is connected as shown in the line 34 between the IGWH inlet 24 and the valve 36 as shown.
During a demand for hot water supply from the system 10 , pressurized hot water at temperature T TANK is discharged from the tank outlet 30 to the open fixture(s) served by line 42 while at the same time pressurized cold water, at temperature T COLD , from a source, is flowed through line 32 into the segment of the line 34 between the IGWH outlet 26 and the bypass valve 36 . A portion of this incoming pressurized cold water is flowed into the through IGWH 12 and discharged therefrom, into the line 38 , as heated water, at temperature T HOT . The balance of the incoming pressurized cold, water bypasses IGWH 12 and flows through the valve 36 into the line 34 where it mixes with line 38 to become T MIX , which flows into the interior of the tank 20 via line 40 .
As needed (for example during standby periods of the system 10 ), the electric heating elements 22 may be energized to maintain T TANK at an appropriate level.
It is important to note that the unique use of the cold water bypass valve 36 in the overall interconnecting flow circuitry of the system 10 advantageously permits full flow from tank 20 while allowing a constant volume of T MIX into the tank inlet 28 . The selective bypassing of cold inlet water around IGWH 12 helps reduce pressure loss and limited flow in the heat exchanger portion of IGWH 12 . The bypass ratio of valve 36 may be fixed or adjustable with respect to the outlet temperature T HOT .
As previously mentioned herein, system 10 efficiently functions without the expense of a pump and its associated recirculation piping (although such a pump and associated recirculation piping could be appropriately added to the system if desired). Instead, the “driving” force selectively flowing the tempered water to the plumbing fixture(s) via pipe 42 is simply the pressure of the cold water source coupled to the pipe 40 . Additionally, the combination system 10 is provided with improved hot water supply from Tank 18 due to the provision of the cold water bypass valve 36 in the piping circuitry interconnecting IGWH 12 and SWH 18 .
An alternate embodiment 10 a of the previously described pumpless water heating system 10 is schematically depicted in FIG. 2 . System 10 a is identical to system 10 with the exceptions that (1) valve 36 is replaced with a mixing valve, representatively a thermostatically controlled mixing valve 46 . The mixing valve 46 allows cold water from line 32 to bypass IGWH 12 and mix with T mix from line 38 and flow into tank 20 as T MIX through line 40 . This feature provides for substantially improved temperature control of T MIX by providing a controlled mix of T COLD from line 32 and T HOT discharged from IGWH 12 .
An alternate embodiment 10 b of the previously described pumpless water heating system 10 is schematically depicted in FIG. 3 . System 10 b is identical to system 10 with the exceptions that valve 36 is replaced with a thermal switch (i.e. “Aquastat) 48 and a normally closed solenoid valve 50 . The thermal switch 48 allows cold water from line 32 to bypass IGWH 12 and mix with T HOT from line 38 and flow into tank 20 as T MIX through line 40 . This feature allows for better utilization of the IGWH 12 during low usage (flow) periods by eliminating unnecessary amounts of T COLD into tank 20 . During high usage (flow) periods, T HOT from IGWH 12 will decrease below the set temperature of thermal switch 48 thus activating solenoid 50 to provide a greater volume of T MIX into tank 20 .
An alternate embodiment 10 c of the previously described pumpless water heating system 10 is schematically depicted in FIG. 4 . System 10 c is identical to system 10 b with the exceptions that thermal switch 48 is replaced with a flow sensor 52 and a relay 54 . The flow sensor 52 sends a signal to relay 54 when a predetermined amount of flow is passing through IGWH 12 to activate solenoid valve 50 . Flow sensor 52 can be integral to IGWH 12 or installed in lines 32 , 38 , or 40 . This feature allows for an alternate means to detect heavy usage (flow) periods based on flow conditions rather than temperature conditions. As previously mentioned in alternate embodiment 10 b , solenoid 50 will only activate during high usage (flow) periods in order to make best utilization of IGWH 12 .
An alternate embodiment 10 d of the previously described pumpless water heating system 10 is schematically depicted in FIG. 5 . System 10 c is identical to system 10 b with the exceptions that thermal switch 48 is replaced with flow switch 56 . The flow switch 56 sends a signal to solenoid valve 50 when a predetermined amount of flow is passing through line 32 . This feature allows for a direct signal to solenoid 50 without the use of additional electronics as describe in alternate embodiment 10 c . As previously mentioned in alternate embodiment 10 b , solenoid 50 will only activate during high usage (flow) periods in order to make best utilization of IGWH 12 .
In any of alternate embodiments 10 a , 10 b , 10 c and 10 d , valve 36 as shown in FIG. 1 could be added to line 32 to provide a fixed amount of the incoming fluid to bypass IGWH 12 .
As can be readily seen from the foregoing, the representatively illustrated embodiments 10 , 10 a , 10 b , 10 c , 10 d of the pumpless water heater system of the present invention, compared to conventional combination instantaneous/tank type water heater systems, provide improved water temperature and flow rate control, while at the same time eliminating the complexity and cost of an associated mechanical pumping system.
While the pumpless systems 10 , 10 a , 10 b , 10 c , 10 d illustrated and described herein are representatively water heating systems, principles of the present invention are not limited to water heating but could be alternatively employed to advantage in conjunction with supply systems for other types of fluids. Additionally, while as previously mentioned herein the systems 10 , 10 a , 10 b , 10 c , 10 d are representatively of pumpless configurations, various types of pumps and associated recirculation systems could be appropriately incorporated therein if desired.
In yet a further alternative embodiment, the flow circuitry described herein may be disposed within a self-contained unit that can be operably integrated such that an instantaneous fluid heater could be connected to any fluid storage vessel.
The foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims.
|
A representatively pumpless water heater system has an instantaneous water heater coupled in series with a storage water heater by piping circuitry incorporating a fixed (and selectively fixed) bypass useable to route pressurized incoming cold water sequentially through the instantaneous and storage type heaters. The fixed bypass can also route pressurized incoming cold water to mix with the heated water exiting the instantaneous heater for delivery to the storage heater.
| 8
|
FIELD OF THE INVENTION
The present invention relates to refrigeration oil, which is lubricating oil disposed within a sealed compressor unit. Refrigeration oil is intended to be miscible and compatible with chlorofluorocarbon refrigerants and compatible with copper, steel, and other materials of compressor parts. The invention also relates to antiwear additives for refrigeration oils and to compressor charges comprising refrigeration oil and the refrigerant or working fluid for the compressor.
BACKGROUND ART
Refrigeration oil is a petroleum derivative consisting essentially of either naphthenic or paraffinic base oils which have been highly refined to remove impurities and high boiling fractions (including waxes).
Refrigeration oil must work over an extremely wide temperature range. For example, in a large industrial air conditioner used in an office building, the oil must work at a temperature as low as -50° Fahrenheit (-46° C.) without hardening or flocculating, and must work in temperatures as high as about 300° F. (149° C.) or more without decomposing substantially. This extremely wide temperature range is necessary because the refrigeration oil is alternately heated and cooled during the cycles of compression and expansion of the working fluid. Thus, one requirement for refrigeration oil is that it have a very low floc point, which can be as low as -65° F. (-54° C.) for some applications. Other applications, such as automotive air conditioners, are less critical and require a floc point of only about -15° F. (-26° C.).
Refrigeration oil also must be compatible with chlorofluorocarbon refrigerants, also called "working fluids" herein. In the presence of unstable oil or an instability-promoting additive, these working fluids generate hydrochloric acid. The free hydrochloric acid thus produced is consumed when it attacks ethylenic or aromatic unsaturation or compounds of nitrogen, oxygen, or sulfur in the refrigeration oil to promote sludge formation. Thus, refrigeration oil must be essentially free of either type of unsaturation, nitrogen, oxygen, and sulfur to prevent its decomposition at elevated temperatures in the presence of chlorofluorocarbon refrigerants.
Resistance of a selected chlorofluorocarbon refrigerant to decomposition in the presence of a selected refrigeration oil is measured by the sealed tube stability test. When measured as described below, the sealed tube stability value of the refrigeration oil should be no more than about one percent decomposition of FREON 12 refrigerant under the test conditions. ("FREON" is a trademark of E.I. du Pont de Nemours & Co., Wilmington, Delaware, for refrigerants. "FREON 12" is a trademark for dichlorodifluoromethane.)
The stability requirements of refrigeration oils are paramount. To avoid instability, formulations of refrigeration oils have avoided using the lubricity-improving additives which are commonly used in other types of lubricants. Kirk-Othmer Encyclopedia of Chemical Technology, 3d ed., Volume 14, page 486 (Table 3) states that no additives are commonly used in refrigeration oils.
A third requirement of refrigeration oils is that they should provide a consistently high level of lubricity to protect the working parts of the compressor.
A persistent problem in the art has been to find additives which will increase the lubricity of a refrigeration oil without sacrificing its low floc point and great resistance to decomposition.
U.S. Pat. No. 4,800,013, issued Jan. 24, 1989 (and therefore not prior art under 35 U.S.C. §102(b)), teaches a refrigeration oil composition comprising a mixture of a paraffin base oil and a naphthenic base oil. This reference discloses the production, and some of the characteristics required, of refrigeration oils according to the present invention. This patent does not disclose halogenated paraffins.
Elsey et al., "A Method Of Evaluating Refrigerator Oils", Refrigerating Engineering, July 1952, pages 737-742, discloses that refrigerants can react with petroleum-based lubricating oils to form acid gas and carbonaceous sludge. The chlorine from the halogenated refrigerant reacts with hydrogen from the hydrocarbon oil to carbonize and therefore degrade the oil. The reference discloses that the more chlorine the refrigerant contains, the more readily it reacts with hydrocarbons. Fluorine substituents on the refrigerant are recognized to increase the stability of the refrigerant.
Several references disclose the use of halogenated paraffin waxes or oils in compositions not used as refrigeration lubricants.
U.S. Pat. No. 3,085,868, issued to Champagnat on Apr. 16, 1963, discloses addition of a chlorinated mineral wax to a base oil to provide an improved petroleum fuel oil.
U.S. Pat. No. 4,010,107, issued to Rothert on Mar. 1, 1977, teaches a lubricating oil composition useful as an automobile transmission fluid. This lubricant comprises a base oil, various other ingredients, and a chlorinated olefin containing from about 15 to 50 carbon atoms and from 20% to about 60% by weight chlorine. The addition of the chlorinated olefin is taught to prevent or retard corrosion of metal parts of the transmission. The patent does not mention floc points at all. It is also not apparent whether the "chlorinated olefins" discussed in this patent have all their olefinic groups chlorinated, which is necessary to avoid reaction of the composition with chlorofluorocarbon refrigerants.
U.S. Pat. No. 4,200,543 was issued to Liston, et al in Apr. 29, 1980. This patent teaches an internal combustion engine crankcase oil comprising various sulfur-containing anti-oxidants, oil-soluble chlorinated hydrocarbons containing at least six carbon atoms, and an oil-soluble zinc salt. At Column 2, lines 35-45, the patent suggests that the oil-soluble chlorinated hydrocarbon alone does not provide any of the anti-oxidant properties necessary in crankcase oil. The use of chlorinated paraffin waxes is suggested at Column 4, lines 18-23.
In short, references which disclose refrigeration oils have not disclosed chlorinated hydrocarbon lubricant additives at all, and references disclosing chlorinated hydrocarbon additives do not contemplate their use in refrigeration oils. The prior art teaches away from the addition of chlorinated hydrocarbons which lack fluorine substitution to a compressor charge.
SUMMARY OF THE INVENTION
The object of the present invention is a refrigeration oil composition which has the necessary floc point, sealed tube stability, and freedom from sludge promoting impurities, and which also has improved lubricity. Other objects will be apparent from the specification and claims which follow.
One aspect of the present invention is a refrigeration oil composition comprising at least 50% by weight of a refined petroleum (or equivalent) oil and enough of a halogenated paraffin to increase the Falex failure load of the composition. The refined oil is selected from naphthenic oils, paraffinic oils, and mixtures of the two. The refined oil requires a sealed tube stability value, at 200° F. (93° C.) for 48 hours, of less than about 1% decomposition of the refrigerant used in the test. The halogenated paraffin has an average carbon chain length of from about 10 to about 30 carbon atoms, and a combined halogen content of from about 20% to 70% by weight. The preferred halogen is chlorine. The overall composition has a floc point of minus 15° F. (minus 26° C.) or lower. The complete composition also has a sealed tube stability value at 200° F. (93° C.) for 48 hours of no more than about 0.3% greater refrigerant decomposition than the sealed tube stability of the refined oil alone.
A second aspect of the invention is an antiwear additive composition for refrigeration oil. This composition can be blended with conventional refrigeration oils to provide a greater degree of lubricity to the product. This composition comprises at least 25% by weight of refined oil as described above and at least 25% by weight of a halogenated paraffin as described above. The inventors believe that halogenated paraffins of this type have not previously been incorporated in refrigeration oil. The purpose of the refrigeration oil in this additive composition is to improve the miscibility of the product in conventional refrigeration oils.
A third aspect of the invention is a refrigerator compressor lubrication oil charge consisting essentially of from about 1% to about 30% by weight, of a chlorofluorocarbon working fluid and from about 70% to about 99% by weight of a lubricant as described above.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
This invention is described in connection with certain exemplified embodiments. These embodiments are provided by way of illustration only, and do not limit the full scope of the invention as defined in the claims at the end of this specification. Percentages used herein are by weight unless otherwise indicated.
Broadly, the refined oil and halogenated paraffin are as specified in the Summary.
The refined oils useful herein are conventional refrigeration oils. Kirk-Othmer Encyclopedia of Chemical Technology (3d ed.), Volume 14, page 484-496, especially page 486, and Volume 17, page 262, are hereby incorporated herein by reference to show the common characteristics of refrigeration oils. U.S. Pat. No. 4,800,013, issued on Jan. 24, 1989 to Yamane et al. and cited previously, is hereby incorporated by reference for its disclosure of naphthenic and paraffinic base oils and the method in which they are refined and treated to provide refrigeration oils. Refrigeration oils typically have a viscosity of between about 15 and about 100 centistokes at 40° C.
One such refrigeration oil contemplated herein is an ISO 32 viscosity grade naphthenic oil (i.e.. having a nominal viscosity of 32 centistokes at 40° C., as defined by the ISO viscosity standard) which is refined by means such as hydrotreating or hydrogenation of the basic oil. This oil is commonly referred to as yellow refrigeration oil because its color ranges from pale to dark yellow. Yellow refrigeration oil typically has a sealed tube stability of less than 1% decomposition of FREON 12 refrigerant at 200° F. (93° C.) for 48 hours.
Another contemplated refrigeration oil is either a more severely refined, similar viscosity naphthenic oil or a similarly refined, similar viscosity paraffin. If a paraffin is used, it should be aggressively dewaxed to eliminate higher paraffins. (Higher paraffins increase the floc point temperature of the composition.) These oils are water-white in color, so they are commonly known as white refrigeration oils. Because of the need to aggressively dewax paraffin source oils, naphthenic source oils are preferred for use herein.
One particular line of hydrotreated naphthenic refined oils useful herein is the HydroCal II line of lubricants. (HydroCal® and HydroCal II® are registered trademarks for lubricants sold by Calumet Industries, Inc., Chicago, Illinois). This particular line of refrigeration oils has a sealed tube stability of less than 0.5% decomposition (as measured herein). The floc points of these refined oils vary, but can be as low as a product specification of minus 65° F. (-54° C.). Refrigeration oils meeting the characteristics required in the present invention are also available from other commercial sources.
The halogenated paraffins useful herein are substituted alkanes. They can have a variety of carbon or alkyl chain lengths, but the preferred oils have a carbon chain length of from about 10 to about 30 carbon atoms, the lower limit being provided so the resulting refrigeration oil is not particularly volatile and the upper limit being provided so the halogenated paraffin will not cause flocculation at the lower temperature ranges required of refrigeration oils. The preferred halogenated paraffins have an average alkyl chain length of from 10 to 24 carbon atoms, more preferably from 10 to about 15 carbon atoms.
The combined halogen content of the halogenated paraffin is conveniently sufficient that a small quantity of this additive can be employed in the refrigeration oil. The more halogenated the paraffin is, the less is required to provide the benefits of the invention. The upper limit of halogenation is dictated primarily by the difficulty of more completely halogenating a paraffin. Neither the lower or upper limit is considered critical. The combined halogen content preferably is from about 20% to about 70% by weight, preferably from about 30% to about 60% by weight, more preferably from about 40% to about 50% by weight.
The halogen used in the halogenated paraffin is selected from chlorine, fluorine, or bromine. Chlorine is specifically contemplated herein. Halogenated paraffins which are both chlorinated and fluorinated are also contemplated herein. The inventors predict that these may provide a greater sealed tube stability than a chlorinated paraffin.
The combinations of refined oil and halogenated paraffin contemplated herein generally contain at least about 25% of the refined oil, preferably at least about 50% of the refined oil, more preferably from about 75% to about 99.5% by weight of the refined oil, still more preferably from about 90% to about 99% by weight of the refined oil, most preferably from about 95% to about 99% by weight of the refined oil. Smaller proportions of refined oil are contemplated for compositions which are intended to be added to a quantity of refrigeration oil to provide increased lubricity. Percentages of the refined oil in the upper parts of the ranges just described are contemplated in compositions to be used directly as refrigeration lubricants.
The combinations of refined oil and halogenated paraffin contain enough of the halogenated paraffin to increase their lubricity, and generally contain from about 0.5% by weight to about 50% by weight, preferably from about 1% to about 10% by weight, more preferably from about 1% to about 5% by weight of the halogenated paraffin. Both concentrates of the halogenated paraffin in refrigeration oil and ready-to-use compositions containing less of the halogenated paraffin are contemplated in the above-stated proportions. The composition containing the halogenated paraffins in concentrated form can be diluted by the end user in additional oil for direct use as a refrigeration lubricant.
Expressed functionally, the minimum proportion of the halogenated paraffin contemplated herein is an amount sufficient to increase the Falex failure load of the composition. A conventional refrigeration lubricant typically has a Falex failure load of substantially less than about 1000 pounds (4400 Newtons) as measured herein. The present refrigeration oil compositions contain enough of the halogenated paraffin to increase their Falex failure loads to at least 1000 pounds (4400 Newtons), preferably at least about 2000 pounds (8900 Newtons), and most preferably at least about 3000 pounds (13,000 Newtons).
The refrigeration oil composition generally should have a floc point of about minus 15° F. (-26° C.) or lower. For demanding applications, the floc point may be required to be about minus 40° F. (-40° C.) or lower, about minus 50° F. (-46° C.) or lower, or even about minus 60° F. (-51°C.) or lower for high performance applications.
Another way of describing the present refrigeration oil compositions is by comparing the properties of the complete composition to the properties of the refined oil alone. The refrigeration oil composition of the present invention preferably has a floc point no more than 5° F. (2.9° C.) higher than the floc point of the refined oil it contains. The sealed tube stability at 200° F. (93° C.) for 48 hours of the claimed composition is preferably no more than 0.3% greater decomposition of FREON 12 (dichlorodifluoromethane), most preferably no more than 0.2% greater decomposition of FREON 12 refrigerant, than the sealed tube stability of the refined oil alone.
The complete composition is preferably essentially free of nonhalogenated paraffin wax, sulfur, nitrogen and oxygen. The refrigeration oils described herein are considered to be essentially free of nonhalogenated paraffin wax if they have a floc point no higher than -20° F. (-29° C.). While there are some sulfur-containing antiwear additives which may provide some benefit in refrigeration oils, the preferred compositions are free of sulfur because it can be a source of instability. Compositions herein are considered to be essentially free of sulfur if they contain less than about 1% by weight sulfur, preferably less than about 0.1 weight percent sulfur, expressed in terms of elemental sulfur. A refrigeration oil composition is considered essentially free of nitrogen if it contains less than about 0.1% elemental nitrogen, and is considered essentially free of oxygen if it contains less than about 0.1% of elemental oxygen.
The refrigeration lubricant compositions described herein are used by incorporating them in either semi-hermetic or hermetic compressor units. The compressor units are separately charged with a refrigerant (charged to the cooling coils or a coolant reservoir) and a lubricant (charged to the sump or other lubricant reservoir). After operation of the unit, some of the coolant intermixes with the lubricant, particularly in the lubricant reservoir, to form a composite charge of the compressor working fluid and refrigeration oil.
The charge of compressor working fluid and refrigeration oil contemplated herein consists essentially of from about 1% to about 30% by weight preferably from about 5% to about 10% by weight, for most applications, of a chlorofluorocarbon working fluid and from about 70% to about 99% by weight, preferably from about 90% to about 95% by weight for most applications, of a lubricant as described above. Chlorofluorocarbon working fluids or refrigerants useful herein are any chlorofluorocarbons conventionally used for refrigeration. A list of such refrigerants can be found in Volume 10, page 866 of the Kirk-Othmer Encyclopedia of Science and Technology, 3rd Edition. This list is hereby incorporated herein by reference to show the state of the art. The refrigerants used in the sealed tube stability test described below are also specifically contemplated herein as chlorofluorocarbon refrigerants.
Test Methods
The following methods were used in testing the compositions in the examples which follow. Where test results are specified in the claims, they are the results obtained using the presently described methods.
Sealed tube stability was measured according to ASHRAE Standard 97-1983 (published in 1983), with the following modifications. First, each test sample consisted of 0.5 milliliters of the lubricant or oil being tested, mixed with 0.5 milliliters of FREON 12 (dichlorodifluoromethane). Second, a spring steel catalyst cut from 6 mil (150 micron) stock and 0.1 inch (2.5 mm) wide by 1 inch (25 mm) long was the only catalyst used. Third, the sealed tubes were heat-conditioned in a oven at 200° F. (93° C.) for forty-eight hours. Finally, the gases from the heat-conditioned, sealed tubes were collected and analyzed for decomposition of FREON 12 (dichlorodifluoromethane) using a Model MX-S FTIR (Fourier Transform Infrared) spectrometer with 1200S computer hardware, sold by Nicolet Instrument Corp., Madison, Wisconsin. Dichlorodifluoromethane decomposes to form monochlorodifluoromethane, which differs from the former by replacement of one chlorine atom on each molecule with a hydrogen atom. A low percent decomposition value indicates good stability. ASHRAE standard 97-1983 is hereby incorporated herein by reference. The accuracy of the sealed tube stability test, using the described method, is plus or minus about 0.2%.
The floc points of refrigeration oils were measured according to ASHRAE Standard 86-1983 (published in 1983), which provides a number accurate within 5° F. (2.8° C.). That standard is hereby incorporated herein by reference. The lower the floc point, the better for many applications.
The Falex failure load test was run generally according to Test Method A of ASTM Standard D 3233-86 (published in December, 1986). That standard is hereby incorporated herein by reference. The purpose of the test is to measure the lubricity of an oil during extreme pressure metal-to-metal wear. The ASTM standard test was modified as follows. The test pieces used were number 8 pins and ASI-1137 V-blocks, cleaned thoroughly in petroleum ether, avoiding the use of halogenated solvents. Only specimens free of scratches, nicks, etc. were used.
The test pieces, 60 milliliters of the oil to be tested, and either an 800 pound (3558 Newton) or 3000 pound (13,000 Newton) load gauge was used, depending on the failure load range anticipated. The load gauge (whichever one was used) was initially set to provide a 250 pound (1,112 Newton) load. The machine was started and run for 2 minutes. Then the machine was stopped, the load arm was engaged, and the machine was restarted after 2 minutes. The waiting period after the initial run-in allowed temperature equalization and attainment of viscosity equilibrium in the lubricant cup. Better repeatability was assured by this procedure.
Finally, the machine was restarted and run with a progressively increasing load until the test pieces failed, typically due to the pin becoming welded to the V-block and snapping. Failure was assumed to occur when the direct load dropped significantly, indicating that the pin had broken. The load at failure was recorded. The higher the load was at failure, the better. 3000 pounds (13,000 Newtons) is the maximum load which the 3,000-pound load gauge can apply. Failure loads of 3000 + pounds (13,000 + Newtons) indicate that the test pieces never failed when tested up to 3000 pounds (13,000 Newtons) force.
EXAMPLES
Table I below describes the halogenated paraffins, other additives, and refrigeration oil compositions used in the examples. The refrigeration oil compositions for the examples were made up by diluting the stated percentage by volume of each additive in HydroCal® RO-15 refrigeration oil (a hydrotreated, yellow naphthenic oil). The sealed tube stability of HydroCal® RO-15 oil by itself is about 0.4% to 0.5% decomposition. Its Falex failure load is about 700 pounds (3100 Newtons). Its floc point is about -65° F. (-54° C.) or lower. (RO-15 is a trademark of Calumet Industries, Inc., Chicago, Illinois).
The examples within the scope of the present invention contain a halogenated paraffin additive, have a sealed tube stability of no more than about 0.7 to 0.8% decomposition, have a Falex failure load exceeding about 700 pounds, and have a floc point of about -15° F. (-26° C.) or lower. Thus, examples A through G met all the criteria which were measured. Examples H, I, and J had a somewhat greater than desirable percent degradation, but still provided the desirable lubricity of the present invention.
Table I illustrates that short- and long-chain halogenated paraffins (including some waxes) containing various amounts of combined halogen are useful refrigeration oil additives. Additives having various viscosities are useful herein. Chlorinated paraffins having similar chemical structures, chain lengths, and chlorine contents can provide different results, which means that one should measure all the relevant parameters of a refrigeration oil, and particularly its sealed tube stability, before concluding that an additive in the oil is useful according to the present invention.
Table I also shows (Examples K, L, and M) that some fatty acids and some fatty acid esters may have marginal utility. They are not preferred, however, because they provide a sealed tube stability (decomposition value) which exceeds the decomposition of the base oil by more than 0.3%.
The test was also run using 3% tricresyl phosphate (TCP) (Example P) or a much smaller proportion of dibenzyl disulfide (DBDS) (Example 0) as antiwear additives. These are two antiwear additives commonly used in lubricants for other uses. These additives improved the antiwear properties of the compositions, but at the expense of their sealed tube stability. (Their decomposition values were not within 0.3% of the decomposition value of the base oil.)
Finally, the floc point of composition D was measured and found to be minus 70° F. (-57° C.), thus demonstrating that a composition according to the present invention can have a desirably low floc point.
TABLE I______________________________________Part 1______________________________________ Example: A B C D E______________________________________Chem. type.sup.1 nP nPW nP nP nPChain Length.sup.2 12 20-24 11 10-13 15% Chlorine 41 45 50 49 51Viscosity.sup.3 51 10,500 350 420 1500% Additive.sup.4 3 3 3 3 3% Degradation.sup.5 0.5 0.6 0.7 0.7 0.7Falex lbf.sup.6 3000.sup.+ 3000.sup.+ 3000.sup.+ 3000.sup.+ --Falex, N.sup.7 13,300.sup.+ 13,300.sup.+ 13,300.sup.+ 13,300.sup.+ --______________________________________Part 2______________________________________ Example: F G H I J______________________________________Chem. type nPW nPW nP nPW nPWChain Length 24 20 11 20-24 24% Chlorine 43 38 55 42 50Viscosity -- 560 810 5100 44,000% Additive 3 3 3 3 3% Degradation 0.8 0.8 1.0 1.1 1.1Falex lbf -- -- 3000.sup.+ -- --Falex, N -- -- 13,300.sup.+ -- --______________________________________ Example: K L M N O P______________________________________Chem. type FA FAE FA nPW DBDS TCPChain Length 16-18 16-18 18 -- -- --% Chlorine 30 33 28 70 -- --Viscosity 2100 650 2000 5000 -- --% Additive 3 3 3 3 0.1 3.0% Degradation 1.2 1.4 1.4 2.3 7.5 7.6Falex lbf 3000.sup.+ 3000.sup.+ -- -- -- --Falex, N 13,300.sup.+ 13,300.sup.+ -- -- -- --______________________________________ .sup.1 Additive Type: nP is normal paraffin oil nPW is normal paraffin wax FAE is fatty acid ester FA is fatty acid DBDS is dibenzyldisulfide TCP is tricresyl phosphate .sup.2 Alkyl chain length of additive (where appropriate); ranges are as stated, single numbers are average values. .sup.3 SUS viscosity of additive at 100° F. (38° C.). .sup.4 % by volume additive in refrigeration lubricant composition. .sup.5 % degradation of CCl.sub.2 F.sub.2 to CHClF.sub.2 of refrigeratio oil during sealed tube stability test. .sup.6 Falex failure load, lbf. .sup.7 Falex failure load, Newtons.
|
Refrigeration oil compositions, additives for forming such compositions, and refrigeration charges comprising a refrigeration oil composition combined with a chlorofluorocarbon refrigerant. The improvement is incorporation the refrigeration oil of a halogenated paraffin as an antiwear additive. Surprisingly, this additive does not substantially decrease the sealed tube stability of the composition, nor does it raise the floc point of the composition when used in an amount effective to increase the Falex failure load of the refrigeration oil composition.
| 2
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/696,229, which was filed on 30 Jun. 2005. U.S. Provisional Application No. 60/696,229 is incorporated by reference in its entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] This disclosure relates generally to electronic circuits, and in particular, to circuits for wireless communication.
[0004] 2. Description of the Related Art
[0005] In a radio receiver, selectivity is an important specification for systems employing multiple frequency channels (e.g., the 2.4 GHz Industrial, Scientific, and Medical (ISM) band). Selectivity is the ability to receive the desired channel frequency (desired, Fd) in the presence of other signals having undesired channel frequencies (undesired, Fu). This is analogous to a person listening to a conversation taking place across the room in a room-full of conversations.
[0006] One method of rejecting the Fu (and only “listening” to Fd) is accomplished with a Band-Pass Filter (BPF), which only allows Fd to pass through it for further processing by the radio circuitry. It can be very difficult and/or expensive to design a BPF at the incoming RF frequency (in this case, 2.4 GHz).
[0007] For example, if the channel frequencies are spaced 1 MHz apart, the BPF bandwidth would have to be approximately 1 MHz to reject the other channels. This would require a Q of 2,400 for a Radio Frequency (RF) BPF (2.4 GHz/1 MHz) but only a Q of 10 for a BPF with an Intermediate Frequency (IF) of 10 MHz (10 MHz/1 MHz). It can be difficult and expensive to design an RF BPF with a Q of 2,400, hence the need to create an IF and perform the filtering at the IF.
[0008] In many low IF transceivers, the transmitter is on the same frequency as the Local Oscillator (LO), but the receiver is not. The receiver LO must be moved by a frequency increment equal to the IF frequency, when compared to the transmitter LO. Assuming that there is only one local oscillator, this requires that the Phase-Locked Loop (PLL) of the frequency synthesizer be re-locked.
[0009] A conventional technique in radio design is to use a Mixer to perform frequency translation (i.e., multiplying two frequencies (F 1 , F 2 ) to obtain the sum and difference frequencies (Fout)=M*F 1 +/−N*F 2 (where M or N=1, 2, 3, . . .)=F 1 +F 2 , F 1 −F 2 , 2*F 1 +/−F 2 , 2*F 2 +/−F 1 , 3*F 1 +/−2*F 2 , etc.).
[0010] A simple case is where a user wants to convert an incoming RF signal (e.g., F RF =2.402 GHz) to an IF (e.g., 1 MHz). This is accomplished by mixing F RF with a local oscillator frequency (LO) of F LO =2.401 GHz. Note that F RF is 1 MHz “above” F LO . Now observe that F RF =2.400 GHz (1 MHz “below” the LO) also produces a difference frequency of 1 MHz (actually, −1 MHz, which is described as+1 MHz with a spectrum inversion). Thus, 2.400 GHz is the “image” (F Image ) of F RF =2.402 GHz for an F LO of 2.401 GHz and an IF of 1 MHz.
[0011] Radios employing mixers for frequency translation are susceptible to interference from their image frequency. There are conventional techniques, such as the use of image canceling mixers that can obviate this susceptibility. For an IF of 2 MHz and F LO =2.401 GHz (unchanged), F RF =2.403 GHz and F Image =2.399 GHz. Also note the roles of F RF and F Image can be reversed depending on which RF signal is the frequency one wishes to receive. Alternatively, one can use a zero IF receiver, which has no image.
[0012] An illustration of this conventional requirement to re-lock the PLL is illustrated in FIG. 1 , where FIG. 1 is a block diagram illustrating a method of communication between two transceivers according to a conventional technique.
[0013] Referring to FIG. 1 , the operation of the first transceiver is illustrated on the left side of the dotted line, while the operation of the second transceiver is illustrated on the right side of the dotted line. Both the first and second transceiver include only a single LO. The transmitters of the first and second transceivers will always transmit at the frequency of their corresponding LO.
[0014] Initially, the first transceiver transmits to the second transceiver (upper left corner to upper right corner of FIG. 1 ) at 2402 MHz. The receiver of the second transceiver is set to receive at 2402 MHz, but the LO of the second transceiver is set to 2403 MHz in order to perform the mixing operation to downconvert the received signal to 1 MHz IF.
[0015] The first transceiver expects to receive an acknowledgement from the second transceiver that the signal from the first transceiver was received. Since the first transceiver expects to receive a signal from the second transceiver at 2403 MHz, both the first and second transceivers must change the frequency of their respective LO after the first transceiver transmits to the second transceiver.
[0016] That is, the second transceiver must change the frequency of its LO from 2403 MHz to 2402 MHz to transmit to the first transceiver. Likewise, the first transceiver must change the frequency of its LO from 2402 MHz to 2403 MHz in order to perform the mixing operation to downconvert the received signal from the second transceiver to 1 MHz IF.
[0017] According to the conventional technique described above, each time that a data burst is sent there must be at least one change of LO frequency for both the first transceiver and the second transceiver. Changing the LO frequency, however, may require a significant amount of time because the PLL cannot instantly be set to the new frequency. There is always some time required for the PLL to stabilize at the new LO frequency. The re-locking of the PLL with each change of LO frequency implies some latency in the delivery of data. The additional time required to re-lock the PLL also means that the first and second transceivers must be powered for a longer amount of time for each data burst, which negatively affects current consumption and battery life.
[0018] Another conventional solution is to have two independent LOs, one LO for receiving and one LO for transmitting. However, this conventional solution requires more power consumption and chip area, which are also undesirable. Also, there is design difficulty due to possible interactions (“pulling”) between the two oscillators.
[0019] It would be desirable to have a faster PLL lock time with lower current consumption. A lower power PLL is desirable in battery powered applications and faster lock time is desirable also when you transmit/receive data in short bursts where long lower power idle times and/or PLL lock times are a significant fraction of the time it takes to transmit/receive a data packet.
[0020] Embodiments of the invention address these and other disadvantages of the related art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a block diagram illustrating a method of communication between two transceivers according to a conventional technique.
[0022] FIG. 2 is a diagram illustrating a method of selectable high/low side injection according to some embodiments of the invention.
[0023] FIG. 3 is a flow diagram further illustrating the method of improved selectable high/low side injection that was described in FIG. 2 .
[0024] FIG. 4 is a block diagram illustrating a receiver circuit according to some embodiments of the invention.
[0025] FIG. 5 is a block diagram illustrating a receiver circuit according to some other embodiments of the invention.
[0026] FIG. 6 is a circuit diagram that illustrates a selectable inverter suitable for use with embodiments of the invention.
DETAILED DESCRIPTION
[0027] In the paragraphs below, methods and circuits for improved selectable high/low side injection enabling fast turn around in a low IF transceiver is described in accordance with some embodiments of the invention. Embodiments of the invention improve over conventional solutions by taking advantage of the image frequency of a receiver.
[0028] According to embodiments of the invention, a heterodyne receiver uses an Intermediate Frequency (IF) at which to detect (demodulate) the signal. In many modern integrated receivers, the IF is typically from 1 to 3 MHz, and is sometimes referred to as “low IF” because the IF frequency is roughly on the order of the channel spacing of the system. “Low IF” is a relative term, so it should not be interpreted as applying to any particular frequency range.
[0029] Using a 1 MHz IF in a 2.4 GHz band device as an example, a low IF receiver has a LO that is tuned to (in one example embodiment) 2403 MHz. This local oscillator is injected into a mixer, which generates, as its output, the sum and difference frequencies based upon the LO and RF inputs.
[0030] In the hypothetical example above, an incoming RF signal at 2.402 GHz is mixed down to the 1 MHz IF (2403 MHz−2402 MHz) and detected. However, an incoming RF signal at 2.404 GHz may also be mixed down to the−1 MHz IF (2403 MHz−2404 MHz) and detected. This gives rise to two different situations, depending on which one of the incoming RF signals has the desired channel frequency Fd.
[0031] A high-side injection situation is one where the LO frequency is above the desired RF frequency. In this case, the desired RF channel frequency Fd would be 2402 MHz, the LO frequency is 2403 MHz, and the undesired frequency Fu (or image frequency) would be 2404 MHz, since the output of the mixer would be−1 MHz if the RF input was 2404 MHz (2403 MHz−2404 MHz). High-side injection refers to the fact that the LO frequency is above the desired RF frequency.
[0032] A low-side injection situation is one where the LO frequency is below the desired RF frequency. In this case, the desired RF channel frequency Fd would be 2404 MHz, the LO frequency is 2403 MHz, and the undesired frequency Fu (or image frequency) would be 2402 MHz. Low-side injection refers to the fact that the LO frequency is below the desired RF frequency.
[0033] FIG. 2 is a diagram illustrating a method of selectable high/low side injection according to some embodiments of the invention. FIG. 3 is a flow diagram further illustrating the method of improved selectable high/low side injection according to some embodiments of the invention.
[0034] Referring to FIG. 2 , the operation of a master transceiver is illustrated on the left side of the dotted line, while the operation of a slave transceiver is illustrated on the right side of the dotted line. Both the master and slave transceivers include only a single LO. The transmitters of the master and slave transceivers will always transmit at the frequency of their corresponding LO.
[0035] In the master unit, the LO is set to 2402 MHz, and the slave unit should be set to receive at that frequency. The slave unit LO is set to 2403 MHz, and the incoming RF signal is down-converted to 1 MHz IF. The receiver of the slave unit is configured to reject the high-side image, and only receives the low-side signal. Compared to the original RF spectrum, the received spectrum at the slave device is inverted at the 1 MHz IF. In the case of FSK modulation the data will be inverted so that is easily handled with an inverter.
[0036] In the slave unit, the LO is set to 2403 MHz, and the master unit should be set to receive at that frequency. As was indicated above, the LO of the master unit is set to 2402 MHz, and the master unit will also downconvert the received signal to 1 MHz. However, the receiver of the master unit is configured to reject the low-side image, since it only desires to receive the high-side signal.
[0037] Thus, as illustrated in FIG. 2 , the master unit is configured to perform low-side injection, while the slave unit is configured to perform high-side injection. This is in contrast with the conventional solution illustrated in FIG. 1 , where both of the first and second transceivers are configured to perform high-side injection. Similarly, it is also conventional for both of the first and second transceivers to be configured to perform low-side injection.
[0038] To make a connection using this method, the master and slave devices preferably negotiate to determine which one of them will remain in its default injection state (maintains the same LO frequency) while the other one changes its injection mode (switches to a different LO frequency). In other words, one of the master and slave devices is set for low-side injection, while the other one of the master and slave devices is set for high-side injection.
[0039] For purposes of this disclosure, the terms master and slave indicate only that the master device is the one that performs the negotiation between the master and slave devices to determine which one of them will remain in the default injection state while the other one changes its injection mode and LO frequency. In some situations, the outcome of the negotiation may not require any changes among the master and slave devices, as they may already be configured in the appropriate manner, i.e., one of the master or slave units performs high-side injection, while the other one performs low-side injection.
[0040] In alternative embodiments of the invention, the negotiation process may be omitted altogether. This may occur, for example, when two devices that are meant to be used together are shipped from the factory and are pre-configured so that one device performs high-side injection and the other device performs low-side injection. An example of two such devices may be, for instance, a wireless keyboard and a USB dongle.
[0041] In preferred embodiments of the invention, since either unit could be the master or the slave unit, each one of the devices is capable of switching between high-side and low-side modes of injection. According to the described embodiments of the invention, the improved solution enables the LO frequency in each of the master and slave devices to remain at the same frequency for both the receive mode and the transmit mode.
[0042] FIG. 3 is a flow diagram further illustrating the method of improved selectable high/low side injection that was describe in FIG. 2 . The flow diagram of FIG. 3 illustrates some exemplary processes in the method, but does not necessarily illustrate all processes in the method. Furthermore, all of the exemplary processes illustrated in FIG. 3 are not necessarily required to practice embodiments of the invention. That is, inventive aspects may exist in as few as one of the exemplary processes illustrated in FIG. 3 .
[0043] Referring to FIG. 3 , according to some embodiments of the invention negotiation occurs between the master transceiver and the slave transceiver at process 310 . The negotiation process 310 is for determining which one of the master and slave transceivers will remain in its default injection state (maintains the same LO frequency) while the other one of the master and slave transceivers changes its injection mode (switches to a different LO frequency).
[0044] As indicated in FIG. 3 , the negotiation process between master and slave transceivers is optional. For example, according to other embodiments, two transceivers that are intended to be used together are may be pre-configured so that one transceiver performs high-side injection and the other transceiver performs low-side injection. An example of two such transceivers may be, for instance, a wireless keyboard and a USB dongle. In such a situation no negotiation would be required.
[0045] In process 320 , the injection mode of one of the master and slave transceivers is changed based upon the result of the negotiation process 310 . The change results in configuration of the master and slave transceivers such that one of the master and slave transceivers is configured for high-side injection, while the other one of the master and slave transceivers is configured for low-side injection.
[0046] As indicated in FIG. 3 , the process 320 is also optional. For example, it may be the case that the outcome of process 310 determines that the master and slave transceivers are already configured such that one of the master and slave transceivers is configured for high-side injection, while the other one of the master and slave transceivers is configured for low-side injection. In such a situation, it would not be necessary to change the configuration of one of the master or slave transceivers.
[0047] In process 330 , a transmission from the master transceiver to the slave transceiver occurs. At the time of the transmission, the LO of the master transceiver has a frequency of F LO(M) =X Hz, while the LO of the slave transceiver has a frequency of F LO(S) =Y Hz. The signal transmitted from the master transceiver is also at X Hz. If Y>X, then the slave transceiver performs high-side injection. However, if Y<X, then the slave transceiver performs low-side injection. For the particular example given in FIG. 2 , F LO(M) =2402 MHz and F LO(S) =2403 MHz, so high-side injection is performed by the slave device.
[0048] In process 340 , a transmission from the slave transceiver to the master transceiver occurs. Between process 330 and process 340 , the LO of the master transceiver is maintained at a frequency of F LO(M) =X Hz, while the LO of the slave transceiver is maintained at a frequency of F LO(S) =Y Hz. The signal transmitted from the slave transceiver is also at Y Hz. If X>Y, then the master transceiver performs high-side injection. If X<Y, then the master transceiver performs low-side injection. For the particular example given in FIG. 2 , F LO(M) =2402 MHz and F LO(S) =2403 MHz, so low-side injection is performed by the master device.
[0049] FIG. 4 is a block diagram illustrating a receiver circuit 400 according to some embodiments of the invention.
[0050] Referring to FIG. 4 , the receiver circuit 400 includes an input from an antenna 410 and a low noise amplifier 420 , the low noise amplifier having an output and an input that is coupled to the input from the antenna.
[0051] The receiver circuit 400 further includes a quadrature mixer 430 and an in-phase mixer 440 , which are both coupled to the output of the low noise amplifier 420 .
[0052] The receiver circuit 400 further includes a local oscillator LO 450 , whose output is connected directly to the in-phase mixer 440 .
[0053] The receiver circuit 400 further includes a first quadrature phase shift block 460 , which phase shifts the output of the LO 450 by a quarter wavelength (π/2) before supplying it as input to the quadrature mixer 430 .
[0054] The receiver circuit 400 further includes a second quadrature phase shift block 470 . The second quadrature phase shift block 470 is coupled to an output of the quadrature mixer 430 , and supplies a quarter wavelength (π/2) of phase shift to the output of the quadrature mixer.
[0055] The receiver circuit 400 further includes a selectable inverter 490 . The input of the selectable inverter 490 includes the output of the in-phase mixer 440 and an external control signal EXT. The selectable inverter 490 is configured to generate as output either the output of the in-phase mixer 440 or an inverted version of the output of the in-phase mixer according to the state of the external control signal EXT.
[0056] The receiver circuit 400 further includes a summer 480 . The summer 480 performs a summing function on the output of the second quadrature phase shift block 470 and the output of the selectable inverter 490 , producing an intermediate frequency IF output.
[0057] FIG. 5 is a block diagram illustrating a circuit 500 according to some other embodiments of the invention.
[0058] Referring to FIG. 5 , a receiver circuit 500 includes an input from an antenna 510 and a low noise amplifier 520 , the low noise amplifier having an output and an input that are coupled to the input from the antenna.
[0059] The receiver circuit 500 further includes a quadrature mixer 530 and an in-phase mixer 540 , which are both coupled to the output of the low noise amplifier 520 .
[0060] The receiver circuit 500 further includes a local oscillator LO 550 , whose output is connected directly to the in-phase mixer 540 .
[0061] The receiver circuit 500 further includes a first quadrature phase shift block 560 , which phase shifts the output of the LO 550 by a quarter wavelength (π/2) before supplying it as input to the quadrature mixer 530 .
[0062] The receiver circuit 500 further includes a selectable inverter 570 . The input of the selectable inverter 570 includes the output of the in-phase mixer 540 and an external control signal EXT. The selectable inverter 570 is configured to generate as output either the output of the in-phase mixer 540 or an inverted version of the output of the in-phase mixer according to the state of the external control signal EXT.
[0063] The receiver circuit 500 further includes a complex Band Pass Filter (BPF) 580 that is coupled to the outputs of the inphase mixer 540 and the quadrature mixer 530 . The BPF 580 includes an Intermediate Frequency In-phase output (IF I) and an Intennediate Frequency Quadrature output (IF Q). In the IF I and IF Q outputs, the image frequency has been rejected by the complex BPF.
[0064] Although a low-noise amplifier 420 , 520 was included in the embodiments of the invention illustrated in FIGS. 4 and 5 , in alternative embodiments the low-noise amplifier need not be present. For example, one could connect an antenna output directly to the input of the image rejection structure if the overall system requirements (such as Gain, noise figure, etc.) could be achieved without using a low-noise amplifier.
[0065] Both of the receiver circuits 400 , 500 of FIGS. 4 and 5 are agile, where for purposes of this disclosure the term agile refers to the fact that a user may configure the receiver circuits to reject either the low-side image or the high-side image.
[0066] A user may accomplish this because, in the circuits illustrated in FIGS. 4 and 5 , any one of the signals on any of the ports of the mixers or the phase shifters can be simply inverted, and the opposite side will be rejected. That is, by changing the polarity of one of the signals on either one of the mixers or phase shifters one can cause the circuit 400 , 500 to reject the RF signal that is above the LO and pass the other RF signal, or alternatively, cause the circuit to reject the RF signal that is below the LO and pass the other RF signal. In other words, the receiver circuits 400 , 500 may be configured to perform either high side injection or low side injection.
[0067] The agility of the receiver circuits 400 , 500 are provided by the presence of the selectable inverters 490 and 570 , which are controlled by the external signal EXT. Depending on the state of the control signal EXT, the selectable inverters 490 , 570 generate an output that is either the same as the non-external input to the selectable inverter or an inverted version of the non-external input to the selectable inverter.
[0068] The illustrated positions of the selectable inverters 490 , 570 within the circuits 400 , 500 are exemplary. Since it is typically easier to invert a signal at lower frequencies, according to preferred embodiments of the invention the signal is inverted at the output of either one of the mixers, after the signal has been down-converted into the IF. This situation is illustrated in FIGS. 4 and 5 .
[0069] Alternatively, in circuit 400 , the selectable inverter 490 may be positioned anywhere in the signal path between circuit node A and the summer 480 or between circuit node B and the summer 480 . Likewise, in circuit 500 , the selectable inverter 570 may be positioned anywhere in the signal path between circuit node A and the CBPF 580 or between circuit node B and the CBPF 580 .
[0070] FIG. 6 is a circuit diagram that illustrates a selectable inverter 600 suitable for use with embodiments of the invention. In particular, the selectable inverters 490 and 570 of FIGS. 4 and 5 may have the structure illustrated by the selectable inverter 600 .
[0071] The selectable inverter 600 includes an inverter 610 and a two-position switch 620 that is controlled by the external control signal EXT. Depending on the state of the external control signal EXT, the selectable inverter 600 generates at the output OUT either the signal appearing at the input IN or an inverted version of the signal appearing at the input IN.
[0072] The structure of the selectable inverter 600 of FIG. 6 is very simple and undoubtedly those of skill in the art would be able to fashion many other equivalent circuits or structures that nonetheless perform the functional equivalent of selectively providing either the input signal or an inverted version of the input signal at an output of the selectable inverter.
[0073] In alternative embodiments of the invention, the circuits 400 and 500 may be implemented using differential signals, where the differential pair includes both a true signal and a complementary signal of the true signal. A USB signal, for example, is a differential signal. In this case, the function of the selectable inverters 490 and 570 is to selectively switch the true signal with the corresponding complementary signal in response to the state of the external control signal EXT. This may easily be accomplished with a differential switch or other equivalent circuits, and additional explanation of these specifics is not required for an understanding of this invention.
[0074] In the embodiments of the invention described above, the illustrated components of circuits 400 , 500 give the circuits the capability to automatically reject the undesired signal, i.e., the circuits are capable of performing image rejection.
[0075] However, in alternative circuits according to other embodiments of the invention, the circuit may not include the components required to perform image rejection. For example, although unlikely, it is conceivable that there may be some environments where no image frequencies (no interference) will occur. In this case, there would not be a need to perform image rejection. However, the method of communicating between two transceivers according to embodiments of the invention is still useful at least because, as explained above, it eliminates the latency associated with the requirement to change the LO frequency.
[0076] In alternate embodiments of the invention, the improved solution can work with any heterodyne system, where the master and slave are separated by the final IF. That is, there could be multiple conversions in the receiver. In addition, the improved solution can work with any IF frequency. As used in this disclosure, the term “low IF” is a relative term, and should not be interpreted as applying to any particular frequency range.
[0077] According to embodiments of the invention, one of the important advantages is that the embodiments eliminate the need to re-lock the frequency synthesizer phase- locked-loop (PLL) when switching from receive to transmit modes. This improves latency in data delivery and improves battery life since the device does not have to remain on as long to send/receive a data packet.
[0078] In addition, switching from a high-side injection mode to a low-side injection mode is a very simple matter according to embodiments of the invention. As described above, any signal that is internal to an image reject circuit structure may simply be inverted.
[0079] Another important advantage is that embodiments of the invention allow a fast turn around, from transmit to receive mode, in a transceiver that uses a low intermediate frequency (IF). According to embodiments of the invention, the LO or frequency synthesizer remains at the same frequency for transmit and receive, so that the PLL lock time is not incurred on each change of modes.
[0080] Embodiments of the invention are well-suited to performing various other processes in addition to the processes described in this disclosure, or variations of the processes described in this disclosure, and in a sequence other than that described in this disclosure. According to some embodiments of the invention, the processes described in this disclosure may be performed by processors and other electrical and electronic components, e.g., components that are capable of executing computer readable and computer executable instructions that include code contained in a computer usable medium.
[0081] For purposes of clarity, many of the details of embodiments of the invention and the methods of designing and manufacturing the same that are widely known and not relevant to the invention have been omitted from this disclosure.
[0082] It should be appreciated that reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, it is emphasized and should be appreciated that two or more references to “an embodiment” or “one embodiment” or “an alternative embodiment” in various portions of this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined as suitable in one or more embodiments of the invention.
[0083] Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim.
[0084] Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.
|
A method of communication between a first transceiver having a first local oscillator set at a first frequency and a second transceiver having a second local oscillator set at a second frequency disclosed. The method includes transmitting a first signal at a first frequency from the first transceiver to the second transceiver, transmitting a second signal at the second frequency from the second transceiver to the first transceiver, and receiving the second signal at the first transceiver. The method further includes maintaining the first local oscillator at the first frequency and the second local oscillator at the second frequency during the transmitting of the first signal, during the receiving of the first signal, during the transmitting of the second signal, and during the receiving of the second signal.
| 7
|
FIELD OF INVENTION
The present invention relates to methods and apparatus for separating fines and smaller particles from a rock mixture.
BACKGROUND OF INVENTION
Crushed rock is typically used for many construction applications. Crushed rock is often used as a lower layer for the construction of roads, pavement, and highways. The crushed rock may be spread over the ground, and asphalt or concrete may be applied over the top of the layer of crushed rock.
The crushed rock is often mined from rock quarries. Large rock is crushed and broken into smaller rock particles. During the processing of the larger rock into the crushed rock, dust, fines, and small particulate matter is inherently produced. Many road construction projects require that the crushed rock only contain a minimum level of this “fine” material. Crushed rock that contains too much of this fine material may be rejected as being out of specification. Typically, many road construction projects require that the crushed rock have a content of no more than approximately 5% fine material. The excess fine content in the crushed rock results in an increased amount of oil needed in the asphalt. If the crushed rock contains an excess amount of the fines, then the entire shipment of the crushed rock may be rejected.
Previous attempts to remove fines or lower the fine content of crushed rock have involved expensive and difficult to maintain equipment. Moreover, many of the prior art attempts and designs to remove the fines from the crushed rock results in excessive waste by-products. For example, one such prior art device to remove fines from the crushed rock includes an air separation device. The air separation device uses large fans and turbines to blow the fines from the crushed rock. The fines are collected in receptacles that allow the blown air to pass through. However, the blowing of the fines degradates the fans and turbines of such air separation devices. Constant maintenance and replacements of such fans and turbines is required.
Other attempts to remove the fines from the crushed rock involve the use of log washers. The crushed rock and fines are washed in the log washers with water in order to separate the fines from the crushed rock. The fines typically float, and the fine and are washed from the heavier crushed rock particles. However, the use of the log washers results in waste pools of water containing the fines. Also, the now wet fines removed by the log washer may require additional drying steps or processes before the fines can be used as a material for certain applications.
Also, conventional wet or dry vibrating screens with very fine openings are employed to remove the fines from the crushed rock. Unfortunately, the screens used in the dry screening process have very fine openings, which tend to plug with rock material. Force-drying the fines and crushed rock, prior to the dry screening, alleviates some of problems with the plugging of the openings of the screen, but this step requires additional equipment and labor. Wet screening results in some of the similar discharge water problems as encountered with log washing. As such, the wet and dry screening processes are problematic for various reasons.
SUMMARY OF THE INVENTION
The apparatus and methods described herein provide for fine and dust control and for fine and dust removal from rocks, stones, or other debris obtained from a quarry, wherein such rock, stone, other debris containing fines, dust, or particulate matter would be undesirable in a particular application. The methods and apparatus provide an efficient and effective manner to remove fines and dust from the rock and stones. The methods and apparatus provide less environmental problems as compared to prior art devices and processes.
The methods and apparatus remove fines from the crushed rock and stone by combining an elevated conveyor belt system, a spray system, a material feed hopper, a scraper, and a dust removal discharge chute. A motor operates a conveyor belt, which is angled at a substantial degree relative to the ground, so that the crushed rock material is not conveyed up and over the top of the conveyor belt. The conveyor belt moves in one direction (toward the top of the elevated conveyor) with the fines, while the crushed rock material moves down the conveyor belt in the direction opposite of the travel of the conveyor belt.
In operation, the crushed rock material is fed onto the conveyor belt from the material feed hopper or other material loading means. The conveyor belt and the coarse particles of the crushed rock material move in opposite directions, thereby creating a counter-flow between the conveyor belt and the coarse particles of the crushed rock material. The fines of the crushed rock material move with and are retained on the conveyor belt. The fines remain on the conveyor belt until removed by scraping or other removal means and methods.
The conveyor belt is sprayed with water or other wetting agents. The conveyor belt may be vibrated by cage idlers or other devices. The vibration aids in rolling and bouncing the coarse particles of the crushed rock material down the conveyor belt and providing many opportunities for the dust and fines, on and among the coarse particles, to contact the conveyor belt. The vibration of the conveyor belt tends to discharge the coarse particles from the conveyor belt surface leaving more “open space” on the conveyor belt to collect the fines. More or less vibration influences the gradation of the finished product, and, in some cases, less vibration may be desirable to achieve a certain specification of crushed rock particles. The dust and fines from the crushed rock material are attracted by the water or other wetting agents on the conveyor belt and collect on the conveyor belt. The fines mixed in with the crushed rock, or that are sticking to the crushed rock, are generally separated and collected on the conveyor belt.
A scraper located toward the top and at the underside of the conveyor belt scrapes away the collected fines and dust, which may be directed to the discharge chute and then collected for disposal or sale at the end of the discharge chute. The material being conveyed, moving in the opposite direction of the conveyor belt, moves down the conveyor belt by gravity and into a collection apparatus.
As described herein, the methods and apparatus remove fines from larger rock. As used herein, the term “fines” includes dust, small particles, and other particulate matter mixed in and/or adhered to larger coarse rock particles, crushed rock and stone. The fines are generally the same material as the larger rock, namely crushed limestone, although the methods and apparatus may be used with other rock and stone materials. The fines are typically the material that passes through a 200 mesh on a standard sieve. The term “200 mesh,” is well known to one of ordinary skill in the art and generally refers to a mesh sheet having approximately 200 openings per square inch. The fines that pass through the 200 mesh may be referred to as a −200 material. Typically, crushed rock particles with an excess amount of −200 content may be out of specification for a certain project. Many construction and road building applications require a −200 content of less than 5% by weight, however the exact level will vary depending on the individual specification. As used herein, the term “coarse particles” are the component of the crushed rock mixture separated from the fines. The coarse particles will generally not pass through the 200 mesh.
The methods and apparatus described herein work most efficiently when the mixture of material comprising the crushed rock and fines is in a relatively dry state. Water should not be added to the crushed rock material prior to processing with the methods and apparatus herein described. A wet crushed rock material will reduce the efficiency of the methods and apparatus.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a front, perspective view of the apparatus for removing the fines from the mixture of rock and fines.
FIG. 2 is a right side view of the apparatus for removing the fines from the mixture of rock and fines.
FIG. 3 is a left side view of the apparatus for removing the fines from the mixture of rock and fines.
FIG. 4 is a front view of the apparatus for removing the fines from the mixture of rock and fines.
FIG. 5 is a rear view of the apparatus for removing the fines from the mixture of rock and fines.
FIG. 6 is a top view of the apparatus for removing the fines from the mixture of rock and fines.
FIG. 7 is a schematic view of the belt system, the rock discharge and the fines discharge for removing the fines from the mixture of rock and fines.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The methods and apparatus will now be described with respect to the Figures. An apparatus 10 for removing fines from crushed rock material is shown in FIG. 1 . The apparatus 10 receives a supply of a crushed rock material 50 , which includes a mixture of fines 54 , coarse particles 58 , and other matter. The apparatus 10 separates at least some of the fines 54 from the coarse particles 58 . The apparatus 10 lowers the content of fines 54 in the crushed rock material 50 .
The crushed rock material 50 has been mined or collected from a rock quarry or other source. Typically, most of the large bulky rocks in the crushed rock material 50 , over for example, several inches in size, have already been reduced or crushed.
The apparatus 10 includes a frame 60 that supports a conveyor belt system 100 . The frame 60 is generally constructed of rigid material, such as steel, with sufficient strength to supports the components of the apparatus 10 . The frame 60 may rest on a trailer, the ground, or be integrally connected to further quarry and rock processing equipment.
The conveyor belt system 100 includes a conveyor belt 102 that is moved by a motor 150 . The conveyor belt 102 is positioned in a slanting or sloping manner in which a first end 106 of the conveyor belt 102 is lower than a higher, second end 107 of the conveyor belt 102 . The conveyor belt 102 further includes a top surface 104 and a bottom surface 105 . The material 50 is fed or dropped onto the top surface 104 adjacent or near the second end 107 of the conveyor belt 102 . By dropping the material 50 onto the top surface 104 adjacent or near the second end 107 , the material 50 is allowed to contact much of or a majority of the conveyor belt 102 . The material 50 may be dropped onto the top surface 104 anywhere in the upper third region of the length of the conveyor belt 102 adjacent the second end 107 . By dropping the material in this region of the conveyor bolt 103 , unwanted carryover of the coarse particles 58 with the fines 54 into a discharge chute 250 is reduced.
The motor 150 is in operational engagement with the conveyor belt 102 . The motor 150 actuates a head pulley 153 that causes the conveyor belt 102 to move in an upward or elevating direction, i.e., the conveyor belt 102 moves from the lower, first end 106 toward the higher, second end 107 . A tail pulley 156 provides rotating support to the moving conveyor belt 102 at the first end 106 . The conveyor belt 102 provides an endless belt moving between the head pulley 153 and the tail pulley 156 .
With reference to FIGS. 2 and 3 , a plurality of optional cage idlers 159 may be positioned along the conveyor belt 102 . In the embodiment shown in the Figures, the cage idlers 159 are positioned between the head pulley 153 and the tail pulley 156 . The cage idlers 159 provide a vibrating force to the conveyor belt 102 . The vibration assists in causing the coarse particles 58 to discharge from the conveyor belt 102 , i.e., the coarse particles 58 bounce, tumble, and/or roll down the conveyor belt 102 toward the first end 106 .
The conveyor belt 102 is mounted onto a conveyor frame 180 . The conveyor frame 180 supports the head pulley 153 , the tail pulley 156 , and the cage idlers 159 in an operational engagement with the conveyor belt 102 . The conveyor belt system 100 further includes a pivoting belt adjusting system 190 and a belt angle adjuster 194 to vary the angle of the conveyor belt 102 . The conveyor belt system 100 further includes a tail-pulley belt tensioner.
Most or all of the length of the conveyor belt 102 is provided with a cover 170 to help contain the crushed rock material 50 on or about the conveyor belt 102 . The coarse particles 58 of the crushed rock material 50 may roll down and bounce with such speed and force that the cover 170 is necessary to maintain and collect the coarse particles 58 discharging at the first end 106 instead of the coarse particles 58 bouncing away from the apparatus 10 .
A material feed hopper system 400 feeds or directs the crushed rock material 50 to the conveyor belt 102 . In the embodiment shown, the material feed hopper system 400 includes a hopper 405 with an interior holding portion 410 . The interior holding portion 410 may be supplied with the crushed rock material 50 via a conveyor belt, a bucket lifter, chute, vibrating feeder, belt feeder, etc. or other means to provide the hopper 405 with an even or controlled flow of the crushed rock material 50 . The hopper 405 may be replaced with any device that provides an adjustable, controlled flow of the crushed rock material 50 to the conveyor belt 102 . An even, regulated feed of the crushed rock material 50 is important in obtaining uniform and predictable results from the apparatus 10 .
With reference to FIGS. 5 and 6 , a lower portion of the hopper 405 includes a gate 420 and a movable door 430 . The gate 420 provides an opening for the material 50 to exit from the hopper 405 . The gate 420 opens to the interior holding portion 410 of the hopper 405 . The door 430 is in a movable engagement with the hopper 405 to close and open the gate 420 to permit, stop and regulate the flow of the crushed rock material 50 from the hopper 405 onto the conveyor belt 102 . One or more vibrators 450 may be positioned on or about the hopper 405 to vibrate the hopper 405 to assist in promoting the flow of the crushed rock material 50 from the hopper 405 , through the gate 420 , and onto the conveyor belt 102 .
The hopper 405 is generally positioned above the conveyor belt 102 . The gate 420 of the hopper 405 is positioned over the second end 107 of the conveyor belt 102 to drop or direct the crushed rock material 50 onto the second end 107 of the conveyor belt 102 . The hopper 405 may hold approximately 1 yard to approximately 100 yards of crushed rock material 50 , although the volume of the hopper 405 may be adjusted depending on the requirements of the apparatus 10 . Moreover, the volume of the hopper 405 may be adjusted to suit the specific application or eliminated entirely. Other systems and means may be employed to provide the regulated flow of the crushed rock material 50 to the conveyor belt 102 . The regulated flow of the crushed rock material 50 may come directly from the hopper 405 , a surge pile fed by a vibrating feeder, a cold-feed bin, a belt feeder, belt scales, or directly linked to an existing plant.
With reference to FIGS. 2 and 3 , a spray system 500 is shown. The spray system 500 includes a tank 510 in fluid communication with a nozzle 520 via a fluid line 530 . A pump 540 pumps fluid from the tank 510 through the fluid line 530 and to the nozzle 520 , which sprays the fluid on a bottom, upper surface of the belt 102 . The nozzle 520 generally sprays most of or the entire width of the conveyor belt 102 . The fluid may include water, a wetting agent, or other solution that causes the fines 54 to stick or adhere to the conveyor belt 102 . The conveyor belt 102 should be sprayed with enough water to moisten the conveyor belt 102 . The amount of fluid sprayed onto the conveyor belt 102 is preferably adjustable in order to accommodate a light or heavy dampening of the conveyor belt 102 depending on the nature, e.g., the moisture, gradation, type of the feed material, and the specification of the desired end product. If too much fluid is sprayed on the conveyor belt 102 , then the discharging of the fines 54 may become sloppy and difficult to manage.
The fluid on the conveyor belt 102 provides for the extraction of the dust and fines from the crushed rock material 50 . The crushed rock material 50 directed or dropped onto the conveyor belt 102 includes the fines 54 that generally stick or adhere to the conveyor belt 102 and are moved upward on the conveyor belt 102 toward the second end 107 .
The coarse particles 58 of the crushed rock material 50 generally tumble or roll down the conveyor belt 102 toward the first end 106 . The fines 54 ride on the conveyor belt 102 up and over the head pulley 153 , where the scraper 200 scrapes the fines 54 from the conveyor belt 102 .
The conveyor belt 102 is generally flat and linear in shape. In other embodiments, the conveyor belt 102 may have a troughed shape on its top surface 104 to better retain the flow of the crushed rock material 50 . The conveyor belt 102 is generally continuous between the first end 106 and the second end 107 . The conveyor belt 102 has a generally smooth surface, i.e., the conveyor belt 102 is free from protrusions or other structures on its top surface 104 .
The conveyor belt 102 may have a width of approximately 1 foot to approximately 5 feet. The conveyor belt 102 may have a length of approximately 4 feet to approximately 30 feet. One of ordinary skill in the art will recognize that these dimensions may be varied (scaled up or down) to accommodate the quarry conditions, the loading and receiving equipment, the amount of the crushed rock material 50 requiring processing, and the processing rates required for the crushed rock material 50 . The conveyor belt 102 may be made from a rubber or an elastomeric material. The conveyor belt 102 may be reinforced with other materials to improve durability. A vulcanized or seamless conveyor belt 102 will often provide more efficient results without wearing on the scraper 200 .
With reference to FIGS. 3 and 7 , the scraper 200 is in generally close contact with the conveyor belt 102 with little or no gap between the edge of the scraper 200 and the conveyor belt 102 . Preferably, the scraper 200 is positioned on the bottom surface 105 of the belt 102 at or near the second end 107 . By scraping the bottom surface 105 , gravity assists in causing the scraped fines 54 to fall away from the conveyor belt 102 . The scraper 200 physically scrapes the fines 54 from the bottom surface 105 of the conveyor belt 102 . The scraper 200 directs the fines 54 into the discharge chute 250 that directs the fines 54 away from the apparatus 10 . In the alternative, the scraper 200 may direct the fines onto a conveyor, vibrating feeder or other device that directs the fines 54 away from the apparatus 10 . The discharge chute 250 may also be in communication with a further conveyor system or other transport system to move the fines 54 away from the apparatus 10 .
The scraper 200 should have a width approximately the same width as the conveyor belt 102 . The scraper 200 may be one continuous length or in staggered, overlapping shorter lengths that clean or scrape most of or all of the entire width of the conveyor belt 102 .
The conveyor belt system 100 generally positions the conveyor belt 102 at an angle of approximately 25° to approximately 65° relative to the ground. This provides a sufficient angle such that the coarse particles 58 roll or fall down the conveyor belt 102 instead of being carried up and over the second end 107 of the conveyor belt 102 . Certain embodiments include the conveyor belt 102 at an angle of approximately 40° to approximately 50° relative to the ground.
The conveyor belt 102 is moving in an opposite direction of the flow of the coarse particles 58 . The motor 150 , via the head pulley 153 , moves the conveyor belt 102 at approximately 2 feet per second to approximately 20 feet per second. This rate of travel is sufficient to remove the fines 54 from the coarse particles 58 on the conveyor belt 102 of approximately 20 feet in length. One of ordinary skill in the art will be able to scale the apparatus 10 up to larger embodiments to process more crushed rock material 50 or vary the speed of the conveyor belt 102 to accommodate different materials. Preferably, the speed of the conveyor belt 102 is variable to accommodate different feed sizes, gradations, desired amount of fines removal, end-use specifications and output volume.
The belt adjusting system 190 and its belt angle adjuster 194 may be variably adjusted depending upon the crushed rock material 50 that is being processed by the apparatus 10 . Generally, the angle of the belt 102 may need to be increased for finer crushed rock material 50 in order to reduce unwanted carryover of coarse particles 58 . Further, the speed of the motor 150 may be increased or slowed down depending upon the nature of the crushed rock material 50 . Generally, the speed of the motor 150 may need to be increased for finer crushed rock material 50 in order to reduce unwanted carryover of coarse particles 58 .
The wetting of the belt 102 provides a wicking action to provide for the fines 54 to stick or adhere to the conveyor belt 102 . The action of the coarse particles 58 tumbling, rolling or flowing down the conveyor belt 102 provides many opportunities to separate the fines 54 from the coarse particles 58 and its surfaces, as the coarse particles 58 contacts the belt 102 multiple times. Some of the fines 54 may be adhered to the coarse particles 58 , and the wicking action of the wet conveyor belt 102 draws the fines 54 to stick to the wet conveyor belt 102 .
The apparatus 10 and methods described herein provide for the separation of materials that are generally of the same type. For example, the fines 54 and coarse particles 58 are both made from limestone. The methods and the apparatus described herein are generally used on a dry crushed rock material 50 . The methods and apparatus provide for loads of the crushed rock material 50 that may be out of specification for a particular construction application, by virtue of an excess fines content, to be processed and re-processed until the fines content is sufficiently reduced. For example, a load of the crushed rock material 50 with an excessive fines content may be repeatedly processed in the apparatus 10 until the fines content is sufficiently lowered.
The fines 54 removed from the coarse particles 58 may be used for many purposes, including, for example, as a fill material, a soil amendment, a mud-jacking medium, mineral filler in asphalt, or a landscaping material. Limestone dust may also act as a natural insecticide.
The following examples describe the use of the apparatus 10 and its ability to reduce the fines content of crushed rock. Table I shows the sieve sizes used to analyze the gradation of the crushed rock material.
TABLE I
SIEVE SIZE
INCH OPENING
⅜″
.3750 (⅜″)
#4
.187 (approx. 3/16″)
#8
.0937 (approx. 3/32″)
#16
.0469 (approx. 3/64″)
#30
.0232
#50
.0117
#100
.0059
#200
.0029
Table II shows the results of a gradation analysis performed on a ¼ inch clean dry screened crushed limestone material. Samples of the crushed limestone were analyzed before processing with the apparatus 10 using the sieves identified in Table I, and the results shown are in the “input material” column of Table II. After processing with the apparatus 10 , the crushed limestone was again analyzed using the sieves identified in Table I with the results shown in the “output material” column of Table II. The output material is the “cleaned” finished product separated from the by-product material, i.e., the fines.
TABLE II
¼″ CLEAN DRY SCREENED CRUSHED LIMESTONE
PERCENT BY WEIGHT PASSING
SIEVE OPENING
Input Material
Output Material
⅜″
100
100
#4
81.1
80.5
#8
25.0
13.2
#16
10.6
6.1
#30
9.1
5.2
#50
8.5
4.8
#100
8.1
4.6
#200
7.3
4.3
As shown in Table II, the −200 content of the crushed limestone has been reduced from 7.3% by weight in the input material to 4.3% by weight of the output material. The crushed limestone could optionally be processed again with the apparatus 10 to further lower the −200 content.
Further tests were conducted on a ⅜ inch clean dry screened crushed limestone material and the results are shown in Table III. The results shown in Table II and III illustrate how the apparatus 10 may be used to remove additional fines from crushed rock that has already been dry screened. Often, dry screened rock falls “out-of-specification” because the dry screening process does not sufficiently remove the fines.
TABLE III
⅜″ CLEAN DRY SCREENED CRUSHED LIMESTONE
PERCENT BY WEIGHT PASSING
SIEVE OPENING
Input Material
Output Material
⅜″
100
100
#4
14.5
13.3
#8
5.1
3.3
#16
4.5
2.8
#30
4.3
2.7
#50
4.1
2.7
#100
4.0
2.7
#200
3.6
2.4
As shown in Table III, the −200 content of the crushed limestone has been reduced from 3.6% by weight of the input material to 2.4% by weight of the output material. The crushed limestone could optionally be processed again with the apparatus 10 to further lower the −200 content.
Table IV illustrates the use of the apparatus 10 on a material made of the end-product fines removed by conventional dry screening processes, generally a ⅛ inch minus dry screened crushed limestone. The end-product fines, after being processed to a consistent gradation, are saleable for manufactured sand. As shown in Table IV, the −200 content of the crushed limestone has been reduced from 31.6% by weight of the input material to 8.7% by weight of the output material, thus improving the consistency of the gradation of the material.
TABLE IV
1/8 ″ MINUS DRY SCREENED CRUSHED LIMESTONE
PERCENT BY WEIGHT PASSING
SIEVE OPENING
Input Material
Output Material
⅜″
100
100
#4
100
100
#8
96.6
93.3
#16
72.3
53.6
#30
57.1
27.7
#50
38.9
14.0
#100
38.9
11.0
#200
31.6
8.7
For the processing described in Tables II, III, and IV, the conveyor belt 102 was set at 42 degrees elevation and the conveyor belt 102 was moving at a speed of 372 feet per minute. The conveyor belt 102 used was 24 inches wide (19 inches between edges of the flashing material) and 6½ feet long. As described above, the width and length of the conveyor belt 102 may be sized up for full-scale processing.
It should be understood from the foregoing that, while particular embodiments of the invention have been illustrated and described, various modifications can be made thereto without departing from the spirit and scope of the present invention. Therefore, it is not intended that the invention be limited by the specification; instead, the scope of the present invention is intended to be limited only by the appended claims.
|
The methods and apparatus separate fines from crushed rock and stone. A motorized conveyor belt system is activated that includes a conveyor belt moving in an upward direction. A spray system is activated to spray a fluid on an underneath surface of the conveyor belt. The mixture of rock and fines are directed to the conveyor belt. The rock tumbles or rolls down the conveyor belt and is collected at a first end of the conveyor belt. The fines stick or adhere to the conveyor belt, and the fines are scraped off of the conveyor belt at or near the second end of the conveyor belt.
The apparatus includes a conveyor belt system, including a moving belt, a motor to move the belt, the belt including a first end and a second end, wherein the second end is elevated relative to the first end. The apparatus includes a spray system, including a source of fluid, a sprayer in fluidic communication with the source of the fluid, and the sprayer positioned to spray a surface of the belt with the fluid. The apparatus includes a material feed system, including a hopper to discharge a material of fines and rock onto the belt proximate the second end of the belt, and the belt moving from the first end to the second end in an upward direction. The apparatus includes a fines discharge to receive fines from the belt and a rock discharge at the first end of the belt.
| 1
|
FIELD OF THE INVENTION
[0001] Generally, the invention relates to litter boxes for pets. More specifically, the invention relates to litter boxes that can be used by dogs as well as cats and that does not require the use of traditional cat litter material.
BACKGROUND
[0002] The following description provides a summary of information relevant to the present invention. It is not an admission that any of the information provided herein is prior art to the presently claimed invention, nor that any of the publications or devices specifically or implicitly referenced are prior art to that invention.
[0003] Cat litter boxes have been in general use by the public for quite some time, and there are many types from which to choose. Generally, the traditional cat litter box is a rectangular container with raised walls on three sides and a lowered wall on the entry side where the cat enters the container. The traditional container holds cat litter material, which is used to attract the cat and absorb cat feces and urine odor. This has worked well for cats, but has not generally been adopted for use by dogs.
[0004] Dogs have traditionally had few options when it comes to relieving themselves indoors. Traditionally, dogs tended to live outdoors and were free to relieve themselves in outdoor areas. More recently, dog owners have been bringing their dogs indoors for several reasons. One reason is that smaller breed dogs have become increasingly popular, and these breeds are suited for indoor living. In fact, they tend to prefer living indoors in close relationship with their owners.
[0005] Another reason for this shift in the living relationship between dogs and humans is that more and more people have been moving into smaller dwelling units that do not have back yards, or have very small outdoor spaces. This shift from traditional homes with yards to smaller homes, such as condos, townhomes and apartments has not reduced people's desire to share their lives with pets. Instead, it has created a greater demand for products that enable indoor living for pets, particularly dogs. Thus, there is now a particular need for products and services that allow pet owners to potty train their pets. There is a corresponding need for indoor pet potties, particularly those suitable for use by dogs.
[0006] As explained above, cats presently have many options that involve using cat litter inside of some form of cat litter box indoors. Dogs, however, have just a few options when it comes to housebreaking and using the bathroom indoors.
[0007] One option is to use a litter box with litter in a manner very similar to what cats use. The problem with such litter boxes for dogs is that dogs like to bury their waste, which results in litter being flung all over the room in which the litter box is placed. In addition, puppies, and some dogs, tend to eat the litter, which is very unhealthy and can lead to serious digestive and other health problems.
[0008] Another option is to lay newspaper or other suitable paper product on the floor and housetrain the dog to use it exclusively. The problem with such an approach is that most paper products don't absorb urine very well, and they tend to leak through to the floor. Moreover, dogs tend to step in the urine on the newspaper and track it all over the house with their paws. Another problem is that puppies tend to tear the paper into shreds and create a big mess all over the house.
[0009] To address these deficiencies in newspaper use, absorbent pads have been created. These pads tend to have one or more layers of absorbent material and a backing layer of material that is impervious to fluid so as to prevent urine from leaking through to the floor beneath the pad. The problem with these absorbent pads, however, is threefold: (1) puppies tend to tear them to shreds as they do with paper products; (2) in their attempt to bury their waste dogs tend to fling the pads out of position and scatter them around so that they are not useful after one use; and (3) the pads do not absorb the urine quickly enough so that dogs tend to track the urine around the house with their paws after stepping in it just after urinating.
[0010] Another solution has been to use large crates that house artificial grass or real sod that is periodically replaced. There are several companies that make various versions of such a product. The problems with that solution are threefold: (1) the artificial grass or sod must be replaced every week or two weeks at most, and even then there is a buildup in odor; (2) these crates tend to be very expensive and can cost between $150 to $600 just for the crate and the first installation of sod; and (3) the replacement sod or grass is also very expensive and results in recurring costs over the entire lifetime of the product.
[0011] Another solution has been the creation of an indoor dog potty that can hold absorbent pads or newspapers in a manner inaccessible to dogs. One such type of dog potty is made of a rectangular base plate fitted with a unitary removable grid. The base plate can hold a newspaper or absorbent pad inside with the grid placed atop the newspaper or absorbent pad. The dog goes to the bathroom atop the grid and the pee passes through the grid to the newspaper or absorbent pad below. The problem with such a product is that the unitary grids tend to be large and difficult to handle and clean. In addition, the grids are often made from lighting louver material or other material and may not be suited for all dogs' paws.
[0012] Thus, there is a need for an affordable, safe, convenient, and clean pet potty that can be used to housetrain pets and provide them with a means to relieve themselves indoors. The present invention solves all of the aforementioned problems associated with current housetraining and indoor potty devices.
SUMMARY OF THE INVENTION
[0013] In accordance with one embodiment, a pet potty includes a base plate and a grid. The base plate has a base and a wall along the perimeter of the base, the base and wall being impermeable to fluid and forming a cavity capable of retaining fluid. The grid is sized to fit within the cavity of the base plate and has a complex of beams that can support a pet atop the grid. The beams have a top side and a bottom side, and substantially all of the beams are convex in shape on their top side.
[0014] In accordance with another embodiment, a pet potty includes a base plate and two or more grids. The base plate has a base and a wall along the perimeter of the base, the base and wall being impermeable to fluid and forming a cavity capable of retaining fluid. The two or more grids are sized to fit within the cavity of the base plate such that when the grids are placed in the cavity the grids are substantially immovable in any horizontal direction. The grids each have a complex of beams that can support a pet atop the grid. The beams have a top side and a bottom side, and substantially all of the beams are convex in shape on their top side.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] These and other features and advantages will be apparent from the following more particular description thereof, presented in conjunction with the following drawings, wherein:
[0016] FIG. 1 is a perspective view of a pet potty in accordance with one embodiment.
[0017] FIG. 2 is an exploded view of the pet potty depicted in FIG. 1 .
[0018] FIG. 3 is a top view of the pet potty depicted in FIG. 1 .
[0019] FIG. 4 is a bottom view of one of the grids of the pet potty depicted in FIG. 1 .
[0020] FIG. 4A is a side view of the grid through lines A-A in FIG. 4 .
[0021] FIG. 4B is a side view of the grid through lines B-B in FIG. 4 .
[0022] FIG. 5 is a three-dimensional close-up view of a portion of the grid depicted in FIG. 4 .
[0023] FIG. 6 is a perspective view of the pet potty depicted in FIG. 1 with a raised drainage attachment.
[0024] FIG. 7A shows a side cut-out view of one of the grids of the pet potty depicted in FIG. 1 with a series of disposable layers adhered to the grid.
[0025] FIG. 7B shows one of the disposable layers of FIG. 7A being peeled off the grid.
[0026] FIG. 8 shows a three-dimensional close-up view of a portion of the grid depicted in FIG. 4 with one of the disposable layers depicted in FIGS. 7A and 7B being peeled off the grid.
DETAILED DESCRIPTION
[0027] The pet potty systems depicted herein can be used to housetrain and act as an indoor potty for dogs and cats. They are, however, particularly suitable for dogs.
[0028] Turning now to FIG. 1 , a pet potty 100 in accordance with one embodiment depicts a rectangular base plate 110 fitted with a double grid system having grids 150 and 160 . The grids 150 and 160 are removable from the base plate 110 . When the grids 150 and 160 are positioned in the base plate 110 the grids fit snuggly in the base plate such that there is little or no movement in any horizontal direction between the grids 150 and 160 and the base plate 110 . The grids are capable of supporting the weight of any breed of dog.
[0029] As shown in FIG. 2 , the base plate 110 is formed of a base 111 surrounded on its perimeter by a raised wall 114 . A raised wall 114 extending upward from the base 111 forms a cavity 115 in the base plate 110 . The wall is preferably about ¾ of an inch tall, but can be from between about ¼ of an inch tall to about 3 inches tall. The grids 150 and 160 fit snuggly within the cavity 115 . The grids 150 and 160 can be removed from the base plate 110 by lifting them vertically upward. Finger ports 157 are provided for this purpose and are positioned on the outer sides of each of the grids 150 and 160 . The grids 150 and 160 are mirror images of each other. The finger ports 157 are placed on the outer sides of the grids 150 and 160 , because there is less likelihood of the outer edges of the grids 150 and 160 being covered with feces.
[0030] The grids 150 and 160 each have a number of spacers 155 along the three outer sides 156 of the grids 150 and 160 . There are no spacers along the side 158 of the grids 150 and 160 that touch each other. The spacers 155 form a space between the outer sides 156 of the grids 150 and 160 and the wall 114 of the base plate 110 . The spacers 155 ensure that there is no horizontal movement between the grids 150 and 160 and the base plate 110 when the grids 150 and 160 are positioned inside the cavity 111 of the base plate 110 . As best shown in FIG. 3 , the spacing between the grids 150 and 160 and the wall 114 of the base plate 110 established by the spacers 155 also makes it easier to grip the finger ports 157 with two fingers. Alternatively, the grids can be sized exactly to fit the cavity 115 of the base plate 110 . As best shown in FIG. 3 , there is no space between the inner sides 158 of the grids, which touch each other.
[0031] The base 111 has a plurality of upwardly projecting bumps 116 formed thereon. The bumps 116 are curved, but can be of any shape and size. The bumps 116 help to stabilize the base 111 and prevent it from warping during the manufacturing process or over time.
[0032] FIG. 4 depicts grid 150 as an example. Each structure and element of grid 150 is mirrored in grid 160 . Grid 150 is formed by a complex of beams 165 that are interconnected within the boundaries of the outer edges 156 and 158 of the grid 150 . The beams 165 of grid 150 are supported by edges 156 and 158 , which extend downward a distance x from the beams 165 of the grid 150 , and by a plurality of columns 170 , which also extend downward a same distance x from the beams 165 . The distance x is preferably about ¾ of an inch, but can be anywhere from about ¼ of an inch to about 3 inches. There can be as few as one column 170 supporting the beams 165 and as many as fifty columns 170 supporting the beams. Preferably, there are at least five columns 170 supporting the beams, as shown in FIG. 4 .
[0033] As best shown in FIGS. 4A and 4B , the beams 165 have a top side 167 and a bottom side 168 . The bottom side 168 of the beams 165 do not extend downward the same distance x as the columns 170 and edges 156 and 158 of the grid 150 . Therefore, the bottom side 168 of the beams 165 do not touch the base 111 of the base plate 110 (both shown in phantom in FIGS. 4A and 4B ).
[0034] As best shown in FIGS. 4A and 5 , the bottom side 168 of the beams 165 can be flat, concave, convex, or any shape. The top side 167 of the beams 165 can be convex (i.e., slightly rounded) in shape. The convex shape of the top side 167 of the beams 165 helps to cushion the paw pads of dogs and cats. The beams 165 are at least 0.15 inches thick (as shown in distance z in FIG. 5 ), which further ensures the safety and comfort of dogs' and cats' paw pads. As shown in FIG. 5 , there are holes or openings between the beams, and the beams 165 are separated by a distance y across the openings between the beams 165 . This distance y between the beams 165 is preferably no greater than about ⅜ of an inch. In any case, distance y is less than ⅝ of an inch. The small distance between the beams reduces the risk that the smallest paw pads of the smallest dog breeds gets stuck inside of the openings between the beams 165 rather than being supported atop the beams 165 .
[0035] An additional feature of the pet potty 100 can be a series 200 of protective disposable layers of material 210 adhered atop the grids 150 and 160 . This feature is best shown in FIGS. 7A , 7 B and 8 . Each disposable layer 210 is made of at least one layer having adhesive material on the bottom side 212 and non-adhesive material on the top side 214 . Alternatively, each disposable layer 210 can be made of two layers of material, a top layer 214 and a bottom layer 212 . The top layer 212 does not have an adhesive, and the bottom layer 214 has an adhesive. The bottom layer 214 (or bottom side) of each disposable layer 210 adheres to the top layer 212 (or top side) of the disposable layer 210 below it. As shown in FIGS. 7B and 8 , each disposable layer 210 can be periodically removed after it is soiled by the pet revealing a clean disposable layer 210 below it. The series of protective disposable layers 200 can be provided in packets of two, three, four, five, six, seven, eight, nine, ten, or more disposable layers 210 . The series of disposable layers 200 preferably has the same general shape and dimensions of the grids 150 and 160 and the length and width of each adhesive layer 210 of the series of disposable layers 200 is generally the same as the beams 165 of the grids 150 and 160 .
[0036] The pet potty 100 is depicted in the figures as being rectangular, but it can be round, oval, square, or any shape that provides enough space for a dog or cat to sit atop and relieve herself or himself. For example, it can be shaped like a bone or a fire hydrant or any other fanciful shape. In one embodiment, such as that shown in the figures herein, the pet potty 100 is about 19 inches in width (shown as W in FIG. 3 ) by about 26 inches in length (shown as L in FIG. 3 ), and the cavity 115 or elimination space can be about 16 inches in width by about 24 inches in length. In other rectangular embodiments, the pet potty 100 can be about 14 inches in width and 19 inches in length with a cavity or elimination space of about 12 inches in width and 15.5 inches in length.
[0037] The grids 150 and 160 can also be of any size or shape. In the embodiment shown in the figures, the grids can be about 12 inches in length by about 16 inches in width each. In yet another embodiment (not shown in the figures), the pet potty can have one large single grid that is about 24 inches in length by about 16 inches in width, rather than having a double grid system such as that shown in the figures.
[0038] As shown in FIG. 6 , the pet potty 100 can be fitted with a raised drainage attachment 300 . The raised drainage attachment 300 can best be utilized by male dogs that raise their legs when they urinate. The drainage attachment 300 can have three walls, leaving an opening along one of the long sides of the pet potty 100 so that the dog has a way to get on the pet potty. Alternatively, the raised drainage attachment 300 can have just one wall, preferably along one of the long sides of the pet potty 100 . The three walls of the drainage attachment 300 can be of a unibody construction made from a single mold. Alternatively, the drainage attachment 300 can be constructed by attaching the three walls together through various types of attachments that are known in the art. Each wall of the drainage attachment 300 has an internal side 315 facing the pet potty 100 , and an external side 320 facing outward and away from the pet potty 100 . The bottom edge of the internal side 315 of the walls forms a drainage lip 310 . The drainage lip 310 extends laterally inward toward the cavity 115 of the base plate 110 of the pet potty 100 . The drainage lip 310 extends just over the internal edge of the perimeter wall 114 of the pet potty such that fluid that drains down the internal walls of the drainage attachment 300 flows into the cavity 115 of the base plate 110 of the pet potty 100 . A retention lip (not shown) can extend inwardly from the bottom edge of the external wall 320 and under the bottom of the base plate 110 . The retention lip can be used to firmly secure the drainage attachment 300 to the pet potty 100 . The drainage attachment 300 can be attached to the pet potty 100 by sliding the pet potty into the groove formed between the bottom of the drainage lip 310 and the top of the retention lip (not shown). The height of the drainage attachment 300 can be any height between about four inches and about twenty-four inches, preferably between about twelve inches and about eighteen inches, and preferably about sixteen inches.
[0039] Although illustrative embodiments of the present invention have been described herein in connection with the accompanying drawings, it is to be understood that this invention is not limited to these embodiments and that various changes and modifications may be effected therein by those skilled in the art without departing from the spirit of the invention.
|
A pet potty includes a base plate and a grid. The base plate has a base and a wall along the perimeter of the base, the base and wall impermeable to fluid and forming a cavity capable of retaining fluid. The grid is sized to fit within the cavity of the base plate and has a complex of beams that can support a pet atop the grid. The beams have a top side and a bottom side, and substantially all of the beams are convex in shape on their top side.
| 0
|
BACKGROUND OF THE INVENTION
[0001] The present application is related generally to the field of underground directional drilling and, more particularly, to an advanced underground homing system, apparatus and method for directing a drill head to a homing target.
[0002] A boring tool is well-known as a steerable drill head that can carry sensors, transmitters and associated electronics. The boring tool is usually controlled through a drill string that is extendable from a drill rig. The drill string is most often formed of drill pipe sections, which may be referred to hereinafter as drill rods, that are selectively attachable with one another for purposes of advancing and retracting the drill string. Steering is often accomplished using a beveled face on the drill head. Advancing the drill string while rotating should result in the boring tool traveling straight forward, whereas advancing the drill string with the bevel oriented at some fixed angle will result in deflecting the boring tool in some direction. A number of approaches have been seen in the prior art for purposes of attempting to guide the boring tool to a desired location, a few of which will be discussed immediately hereinafter.
[0003] In one approach, the boring tool transmits an electromagnetic locating signal. Above ground, a portable detection device, known as a walkover detector, is movable so as to characterize the positional relationship between the walkover detector and the boring tool at a given time. The boring tool can be located, for example, by moving the walkover detector to a position that is directly overhead of the boring tool or at least to some unique point in the field of the electromagnetic locating signal. In some cases, however, a walkover locator is not particularly practical when drilling beneath some sort of obstacle such as, for example, a river, freeway or building. In such cases, other approaches may be more practical.
[0004] Another approach that has been taken by the prior art, which may be better adapted for coping with obstacles which prevent access to the surface of the ground above the boring tool, resides in what is commonly referred to as a “steering tool.” This term has come to describe an overall system which essentially predicts the position of the boring tool, as it is advanced through the ground using a drill string, such that the boring tool can be steered from a starting location while the location of the boring tool is tracked in an appropriate coordinate system relative to the starting position. Arrival at a target location is generally determined by comparing the determined position of the boring tool with the position of the desired target in the coordinate system.
[0005] Steering tool systems are considered as being distinct from other types of locating systems used in horizontal directional drilling at least for the reason that the position of the boring tool is determined in a step-wise fashion as it progresses through the ground. Generally, in a traditional steering tool system, pitch and yaw angles of the drill-head are measured in coordination with extension of the drill string. From this, the drill-head position coordinates are obtained by numerical integration step-by-step from one location to the next. Nominal or measured drill rod lengths can serve as a step size during integration. One concern with respect to conventional steering tools is a tendency for positional error to accumulate with increasing progress through the ground up to unacceptable levels. This accumulation of positional error is attributable to measurement error in determining the pitch and yaw angles at each measurement location. One technique in the prior art in attempting to cope with the accumulation of positional error resides in attempting to measure the pitch and yaw parameters with the highest possible precision, for example, using an optical gyroscope in an inertial guidance system. Unfortunately, such gyroscopes are generally expensive.
[0006] Another approach that has been taken by the prior art, which is also able to cope with drilling beneath obstacles, is a homing type system. In traditional homing systems, the boring tool includes a homing transmitter that transmits an electromagnetic signal. A homing receiver is positioned at a target location or at least proximate to a target location such as, for example, directly above the target location. The homing receiver is used to receive the electromagnetic signal and to generate homing commands based on characteristics of the electromagnetic signal which indicate whether the boring tool is on a course that would ultimately cause it to be directed to the target location. Generally, identifying the particular location of the boring tool is not of interest since the boring tool will ultimately arrive at the target location if the operator follows the homing commands as they are issued by the system. Applicants recognize, however, that such traditional homing systems are problematic with respect to use at relatively long ranges between the homing receiver and the boring tool, as will be discussed in detail below.
[0007] The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.
SUMMARY
[0008] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
[0009] In general, a system includes a boring tool that is moved by a drill string using a drill rig that selectively extends the drill string to the boring tool to form an underground bore such that the drill string is characterized by a drill string length which is determinable. In one aspect, a homing apparatus includes a transmitter, forming part of the boring tool, for transmitting a time varying dipole field as a homing field. A pitch sensor is located in the boring tool for detecting a pitch orientation of the boring tool. A homing receiver is positionable at least proximate to a target location for detecting the homing field to produce a set of flux measurements. A processing arrangement is configured for using the detected pitch orientation and the set of flux measurements in conjunction with a determined length of the drill string to determine a vertical homing command for use in controlling depth in directing the boring tool to the target location such that the vertical homing command is generated with a particular accuracy at a given range between the transmitter and the homing receiver and which would otherwise be generated with the particular accuracy for a standard range, that is different from the particular range, without using the determined length of the drill string. A display indicates the vertical homing command to a user. In one feature, the boring tool is sequentially advanced through a series of positions along the underground bore and, at each one of the positions (i) the pitch orientation is detected by the pitch sensor, (ii) the homing receiver produces the flux measurements and (iii) the drill string is of the determined length such that at least the set of flux measurements is subject to a measurement error and the processing arrangement is configured for determining the vertical homing command, at least in part, by compensating for the measurement error, which measurement error would otherwise accumulate from each one of the series of positions to a next one of the series of positions, to cause the particular range to be greater than the standard range.
[0010] In another aspect, a system includes a boring tool that is moved by a drill string using a drill rig that selectively extends the drill string to the boring tool to form an underground bore such that the drill string is characterized by a drill string length. One embodiment of a method includes transmitting a time varying dipole field from the boring tool as a homing field. A pitch orientation of the boring tool is detected using a pitch sensor located in the boring tool. A homing receiver is positioned at least proximate to a target location for detecting the homing field to produce a set of flux measurements. A length of the drill string is determined. A processor is configured for using the detected pitch orientation and the set of flux measurements in conjunction with the established length of the drill string to determine a vertical homing command for use in controlling depth in directing the boring tool to the target location such that the vertical homing command is generated with a particular accuracy at a given range between the transmitter and the homing receiver and which would be generated with the particular accuracy for a standard range, that is different from the particular range, without using the determined length of the drill string, and indicating the vertical homing command to a user. In one feature, the boring tool is sequentially advanced through a series of positions along the underground bore and, at each one of the positions (i) the pitch orientation is detected using the pitch sensor, (ii) the flux measurements are produced by the homing receiver and (iii) establishing the determined length of the drill string is established such that at least the set of flux measurements is subject to a measurement error. The vertical homing command is determined, at least in part, by compensating for the measurement error, which measurement error would otherwise accumulate from each one of the series of positions to a next one of the series of positions, to cause the particular range to be greater than the standard range.
[0011] In still another aspect, a system includes a boring tool that is moved by a drill string using a drill rig that selectively extends the drill string to the boring tool to form an underground bore such that the drill string is characterized by a drill string length which is determinable. A homing apparatus includes a transmitter, forming part of the boring tool, for transmitting a time varying electromagnetic homing field. A pitch sensor is located in the boring tool for detecting a pitch orientation of the boring tool. A homing receiver is provided that is positionable at least proximate to a target location for detecting the homing field to produce a set of flux measurements. A processing arrangement is configured for using the detected pitch orientation and the set of flux measurements in conjunction with a determined length of the drill string to determine a vertical homing command and a horizontal homing command such that the vertical homing command has a particular accuracy that is different from another accuracy associated with the horizontal homing command for use in controlling depth in directing the boring tool to the target location. In one feature, the particular accuracy of the vertical homing command is greater than the other accuracy of the horizontal homing command.
[0012] In yet another aspect, a system includes a boring tool that is moved by a drill string using a drill rig that selectively extends the drill string to the boring tool to form an underground bore such that the drill string is characterized by a drill string length which is determinable. A method includes transmitting a time varying electromagnetic homing field from the boring tool. A pitch orientation of the boring tool is detected. A homing receiver is positioned at least proximate to a target location for detecting the homing field to produce a set of flux measurements. The detected pitch orientation and the set of flux measurements are used in conjunction with a determined length of the drill string to determine a vertical homing command and a horizontal homing command such that the vertical homing command has a particular accuracy that is different from another accuracy associated with the horizontal homing command for use in controlling depth in directing the boring tool to the target location. In one feature, the particular accuracy of the vertical homing command is generated as being more accurate than the other accuracy of the horizontal homing command.
[0013] In a further aspect, a system includes a boring tool that is moved by a drill string using a drill rig that selectively extends the drill string to the boring tool to form an underground bore such that the drill string is characterized by a drill string length which is determinable and in which the boring tool is configured for transmitting an electromagnetic homing field. An improvement includes configuring an arrangement for using at least the electromagnetic homing field to determine a vertical homing command and a horizontal homing command such that the vertical homing command has a particular accuracy that is different from another accuracy associated with the horizontal homing command for use in controlling depth in directing the boring tool to the target location. In one feature, the arrangement is further configured for generating the particular accuracy of the vertical homing command as being more accurate than the other accuracy of the horizontal homing command.
[0014] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be illustrative rather than limiting.
[0016] FIG. 1 is a diagrammatic view, in elevation, of a region in which a homing apparatus and associated method, according to the present disclosure, are used in a homing operation for purposes of causing a boring tool to home in on a target location.
[0017] FIG. 2 is a diagrammatic plan view of the region of FIG. 1 in which the homing apparatus and associated method are employed.
[0018] FIG. 3 is a diagrammatic view, in perspective, of a portable homing receiver that is produced according to the present disclosure, shown here to illustrate the various components of the homing receiver.
[0019] FIG. 4 is a flow diagram which illustrates one embodiment of a homing method according to the present disclosure.
[0020] FIG. 5 is a diagrammatic illustration of one embodiment of the appearance of a screen for displaying a homing command generated according to the present disclosure.
[0021] FIG. 6 a is a plot which illustrates a simulated drill path in an elevational view for use in demonstrating the accuracy of vertical homing commands produced according to the present disclosure.
[0022] FIG. 6 b is a plot of the vertical homing command along the simulated drill path of FIG. 6 a , which vertical homing command is produced according to the present disclosure.
[0023] FIG. 6 c is a plot of X axis error along the X axis illustrating a difference between actual position along the X axis and determined position for the drill path of FIG. 6 a.
[0024] FIG. 6 d is a plot of Z axis error along the X axis illustrating a difference between actual position along the Z axis and determined position for the drill path of FIG. 6 a.
[0025] FIG. 7 a is a another plot which illustrates another simulated drill path in an elevational view for use in demonstrating the accuracy of vertical homing commands produced according to the present disclosure.
[0026] FIG. 7 b is a plot of the vertical homing command along the simulated drill path of FIG. 7 a , which vertical homing command is produced according to the present disclosure.
[0027] FIG. 7 c is a plot of X axis error along the X axis illustrating a difference between actual position along the X axis and determined position for the drillpath of FIG. 7 a.
[0028] FIG. 7 d is a plot of Z axis error along the X axis illustrating a difference between actual position along the Z axis and determined position for the drillpath of FIG. 7 a.
[0029] FIG. 8 a is a plot which illustrates a simulated drill path in a plan view which is used in conjunction with the elevational view of FIG. 6 a to form an overall three-dimensional simulated drill path for use in demonstrating the effectiveness of vertical homing commands produced according to the present disclosure in view of significant yaw and lateral diversion of the boring tool.
[0030] FIG. 8 b is a plot of the vertical homing command along the simulated drill path cooperatively defined by FIGS. 6 a and 8 a , which vertical homing command is produced according to the present disclosure and with the vertical homing command of FIG. 6 b shown as a dashed line for purposes of comparison.
[0031] FIG. 8 c is a plot of Z axis error along the X axis illustrating a difference between actual position along the Z axis and determined position for the drillpath cooperatively defined by FIGS. 6 a and 8 a and with the Z axis error of FIG. 6 d shown as a dashed line for purposes of comparison.
[0032] FIG. 9 is a plot of the vertical homing command along the X axis, shown here for purposes of comparing the accuracy of the homing commands of a conventional homing system with the accuracy of vertical homing commands generated according to the present disclosure.
DETAILED DESCRIPTION
[0033] The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the described embodiments will be readily apparent to those skilled in the art and the generic principles taught herein may be applied to other embodiments. Thus, the present invention is not intended to be limited to the embodiment shown, but is to be accorded the widest scope consistent with the principles and features described herein including modifications and equivalents, as defined within the scope of the appended claims. It is noted that the drawings are not to scale and are diagrammatic in nature in a way that is thought to best illustrate features of interest. Descriptive terminology such as, for example, upper/lower, front/rear, vertically/horizontally, inward/outward, left/right and the like may be adopted for purposes of enhancing the reader's understanding, with respect to the various views provided in the figures, and is in no way intended as being limiting.
[0034] Turning now to the figures, wherein like components are designated by like reference numbers whenever practical, attention is immediately directed to FIGS. 1 and 2 , which illustrate an advanced homing tool system that is generally indicated by the reference number 10 and produced according to the present disclosure. FIG. 1 is a diagrammatic elevational view of the system, whereas FIG. 2 is a diagrammatic plan view of the system, each figure showing a region 12 in which a homing operation is underway. System 10 includes a drill rig 18 having a carriage 20 received for movement along the length of an opposing pair of rails 22 which are, in turn, mounted on a frame 24 . A conventional arrangement (not shown) is provided for moving carriage 20 along rails 22 . A boring tool 26 includes an asymmetric face 28 ( FIG. 1 ) and is attached to a drill string 30 which is composed of a plurality of drill pipe sections 32 , several of which are indicated. It is noted that the drill string is partially shown due to illustrative constraints. Generally, the drill rig hydraulically pushes the drill string into the ground with selective rotation. Pushing with rotation is intended to cause the boring tool to travel straight ahead while pushing without rotation is intended to cause the boring tool to turn, based on the orientation of asymmetric face 28 . A path 40 of the boring tool includes a series of positions that are designated as k=1, 2, 3, 4 etc. as the boring tool is advanced through the ground. The current position of the boring tool is position k with the next position to be position k+1. The portion of path 40 along which the boring tool has already traveled is shown as a solid line while a dashed line 40 ′, in FIG. 1 , illustrates the potential appearance of the path ahead of the boring tool resulting from the homing procedure. The increment between the positions k and k+1 can correspond to the length of one pipe section, although this is not a requirement. Boring tool 26 enters the ground at 42 , however, the subject homing process can begin at position k=1 at a depth D 1 below a surface 44 of the ground, where a point 45 on the surface of the ground serves as the origin of a coordinate system. As will be seen, the homing operation can be initiated at point 42 where the boring tool initially enters the ground. While a Cartesian coordinate system is used as the basis for the coordinate system employed by the various embodiments disclosed herein, it is to be understood that this terminology is used in the specification and claims for descriptive purposes and that any suitable coordinate system may be used.
[0035] As the drilling operation proceeds, respective drill pipe sections, which may be referred to interchangeably as drill rods, are added to the drill string at the drill rig. A most recently added drill rod 32 a is shown on the drill rig. An upper end 50 of drill rod 32 a is held by a locking arrangement (not shown) which forms part of carriage 20 such that movement of the carriage in the direction indicated by an arrow 52 ( FIG. 1 ) causes section 32 a to move therewith, which pushes the drill string into the ground thereby advancing the boring operation. A clamping arrangement 54 is used to facilitate the addition of drill pipe sections to the drill string. The drilling operation can be controlled by an operator (not shown) at a control console 60 which itself can include a telemetry section 62 connected with a telemetry antenna 64 , a display screen 66 , an input device such as a keyboard 68 , a processor 70 , and a plurality of control levers 72 which, for example, control movement of carriage 20 .
[0036] Still referring to FIGS. 1 and 2 , in one embodiment, system 10 can include a drill string measuring arrangement having a stationary ultrasonic transmitter 202 positioned on drill frame 24 and an ultrasonic receiver 204 with an air temperature sensor 206 ( FIG. 2 ) positioned on carriage 20 . It should be noted that the positions of the ultrasonic transmitter and receiver may be interchanged with no effect on measurement capabilities. Transmitter 202 and receiver 204 are each coupled to processor 70 or a separate dedicated processor (not shown). In a manner well known in the art, transmitter 202 emits an ultrasonic wave 208 that is picked up at receiver 204 such that the distance between the receiver and the transmitter may be determined to within a fraction of an inch by processor 70 using time delay and temperature measurements. By monitoring movements of carriage 20 , in which drill string 30 is either pushed into or pulled out of the ground, and clamping arrangement 54 , processor 70 can accurately track the length of drill string 30 throughout a drilling operation to within a particular measurement accuracy. While it is convenient to perform measurements in the context of the length of the drill rods, with measurement positions corresponding to the ends of the drill rods, it should be appreciated that this is not a requirement and the ultrasonic arrangement can provide the total length of the drill string at any given moment in time. Further, in another embodiment, the length of the drill string can be determined according to the number of drill rods multiplied by nominal rod length. In this case, the rod length may be of a nominal value subject to some manufacturing tolerance at least with respect to its length. In one version of this embodiment, the drill string measurement arrangement can count the drill rods. In another version of this embodiment, the operator can count the drill rods. Of course, in either case, the number of drill rods that is counted can be correlated to the length that is determined by ultrasonic measurement, although there is no requirement for precision overall drill string length measurement.
[0037] Referring to FIG. 1 , boring tool 26 includes a mono-axial antenna (not shown) such as a dipole antenna oriented along an elongation axis of the boring tool and which is driven to emit a dipole magnetic homing signal 250 (only one flux line of which is partially shown). As an example of a boring tool incorporating such a mono-axial antenna in its transmitter arrangement, see FIG. 9 of U.S. Pat. No. 5,155,442 (hereinafter, the '442 patent) entitled POSITION AND ORIENTATION LOCATOR/MONITOR and its associated description. This latter patent is commonly owned with the present application and hereby incorporated by reference. As will be described in detail hereinafter, homing signal 250 is monitored by a homing receiver 260 which will be described in detail at an appropriate point hereinafter. The boring tool is equipped with a pitch sensor (not shown) for measurement of its pitch orientation as is described, for example, in the '442 patent. As is also well known, the pitch orientation and other parameters of interest can be modulated onto the homing signal for remote reception and decoding. In other embodiments, measured parameters can be transferred to the drill rig using a wire-in-pipe configuration such as is described, for example, in U.S. Pat. No. 7,150,329 entitled AUTO-EXTENDING/RETRACTING ELECTRICALLY ISOLATED CONDUCTORS IN A SEGMENTED DRILL STRING, which is commonly owned with the present application and incorporated herein by reference. The parameters may be used at the drill rig and/or transferred to a remote location, for example, by telemetry section 62 . It is noted, however, that the measurement of yaw is not necessary and, therefore, there is no need for a yaw sensor in the boring tool. It is well known that yaw angle is a parameter that is generally significantly more difficult to measure, as compared to pitch orientation. Accordingly, there is some benefit associated with techniques such as described herein which do not rely on measured yaw orientation.
[0038] FIG. 3 is a diagrammatic view, in perspective, which illustrates details of one embodiment of portable homing receiver 260 . The homing receiver includes a three-axis antenna cluster 262 for measuring three orthogonally arranged components of magnetic flux in a coordinate system that can be fixed to the homing receiver itself having axes designated as b x , b y and b z and, of course, transformed to another coordinate system such as what may be referred to as a global coordinate system in the context of which the homing operation can be performed. In one embodiment, the global coordinate system can be the X,Y,Z. One useful antenna cluster contemplated for use herein is disclosed by U.S. Pat. No. 6,005,532 entitled ORTHOGONAL ANTENNA ARRANGEMENT AND METHOD which is commonly owned with the present application and is incorporated herein by reference. Antenna 262 is electrically connected to a receiver section 264 which can include amplification and filtering circuitry, as needed. Homing receiver 260 further may include a graphics display 266 , a telemetry arrangement 268 having an antenna 270 and a processing section 272 interconnected appropriately with the various components. The processing section can include one or more microprocessors, DSP units, memory and other components, as needed. It is noted that, for the most part, inter-component cabling has not been illustrated in order to maintain illustrative clarity, but is understood to be present and may readily be implemented by one having ordinary skill in the art in view of this overall disclosure. It should be appreciated that graphics display 266 can be a touch screen in order to facilitate operator selection of various buttons that are defined on the screen and/or scrolling can be facilitated between various buttons that are defined on the screen to provide for operator selections. Such a touch screen can be used alone or in combination with an input device 274 such as, for example, a keypad. The latter can be used without the need for a touch screen. Moreover, many variations of the input device may be employed and can use scroll wheels and other suitable well-known forms of selection device. The telemetry arrangement and associated antenna are optional. The processing section can include components such as, for example, one or more processors, memory of any appropriate type and analog to digital converters. Generally, the homing receiver can be configured for direct placement on surface 44 of the ground, however, an ultrasonic transducer (not shown) can be provided for measuring the height of the homing receiver above the surface of the ground. One highly advantageous ultrasonic transducer arrangement is described, for example, in the above incorporated '442 patent.
[0039] As will be further described, Applicant recognizes that the accuracy of homing commands depends directly on the accuracy of fluxes measured at the homing receiver. Since dipole field signal strength (see item 250 , in FIG. 1 ) decreases in inverse proportion to distance to the third power, homing accuracy can diminish rapidly with relatively larger distances between the homing transmitter of boring tool 26 and homing receiver 260 . In this regard, it should appreciated that the weakest signal and, hence, the lowest accuracy in a typical homing procedure will be encountered at the start of the operation when separation between the homing transmitter and the homing receiver is usually at a maximum. In a conventional homing system, this initial separation can be beyond the range at which the homing receiver is capable of receiving the homing signal.
[0040] The homing technique and apparatus disclosed herein increases the range over which vertical homing is accurate. Accurate and useful homing commands can be generated over distances much larger than the typical range of 40 feet or so, using a typical battery powered homing transmitter. At a given range between the boring tool and the homing receiver, vertical homing accuracy is remarkably enhanced by using flux measurements in conjunction with integrating pitch for a determined drill string length, as will be further discussed at an appropriate point below.
Nomenclature
[0041] The following nomenclature is used in embodiments of the homing procedure described herein and is provided here as a convenience for the reader.
[0000]
b =
flux magnitude for unit boring tool transmitter
dipole strength
b X , b Z =
flux components in the X, Z - directions
D 1 =
initial boring tool transmitter depth
D T =
target depth below homing receiver
H =
observation coefficient matrix
I =
identity matrix
K =
Kalman gain
L R =
average drill rod length
P =
error covariance matrix
Q k =
discrete process noise covariance matrix
R M =
observation error covariance matrix
{right arrow over (R)} =
position vector from boring tool transmitter antenna
center to the center of the homing receiver antenna
s =
arc length along drill string axis
{right arrow over (v)} b =
vector of flux measurement error
{right arrow over (v)} hr =
vector of homing receiver position error
{right arrow over (x)} =
state variables vector
x hr =
homing receiver x -position in boring tool transmitter
coordinates
X, Z =
coordinate axes of vertical plane in which homing
commands are generated or position coordinates in
this plane
X hr , Z hr =
homing receiver position
X T , Z T =
target position
{right arrow over (w)} k =
process noise vector
{right arrow over (z)} =
measurement vector
δX, δZ =
position state variables
δX hr , δZ hr =
homing receiver antenna position increments
δφ =
pitch angle increment
ΔY, ΔZ =
horizontal and vertical homing commands
φ =
pitch angle
Φ k =
discrete state equation transition matrix
σ =
standard deviation
σ φ =
pitch measurement error
σ b X , σ b Y =
flux measurement errors
σ X hr , σ Z hr =
homing receiver position measurement errors
σ X 1 , σ Z 1 =
initial boring tool transmitter position error
σ 2 =
variance, square of standard deviation
Subscripts
[0042]
[0000]
est
estimated value
ex
exact value
hr
Homing receiver
k
k -th transmitter position
m
measured
T
target
1
initial position of boring tool where homing is initiated
Superscripts
[0043]
[0000]
( • )
d
ds
( ) −
indicates last available estimate
( )′
transpose
( ) *
nominal drill path
x
→
^
state variables vector estimate
[0044] Referring to FIG. 1 , prior to homing, the user may place homing receiver 260 on the ground ahead of the homing transmitter and above a specified target location T, pointing in the drilling direction in one embodiment. Note that the receiver x axis faces to the right in the view of FIG. 1 . That is, the x axis of the receiver, along which flux b x is measured, faces away from the drill rig at least approximately in the drilling direction. In another embodiment, the center of tri-axial antenna 262 of the homing receiver may be chosen as a target T′. This set-up procedure determines an X,Z coordinate system used during homing ( FIG. 2 ) where X is horizontal and Z is vertical. A Y axis extends horizontally and orthogonal to the X,Z plane completing a right handed Cartesian coordinate system. The use of this particular coordinate system which may be referred to herein as a master or global coordinate system, should be considered as exemplary and not limiting. Any suitable coordinate system may be used including Cartesian coordinate systems having different orientations and polar coordinate systems. It should be appreciated that the drill path is not physically confined to the X,Z plane such that homing along a curved path can be performed. The technique described herein, however, does not account for divergence of the boring tool out of the X,Z plane or for yaw angles out of the X,Z plane as represented by boring tool 26 ′ (shown in phantom in FIG. 2 ) for purposes of producing enhanced vertical homing commands while still producing remarkable results. At the time of setup, the X,Z axes define a vertical plane that contains the center of the transmitter antenna at the start of homing and the center of antenna 262 of homing receiver 260 . These axes can remain so defined for the remainder of the homing procedure. In the present example, the origin of this system is located at point 45 on the surface of the ground above the center of the homing transmitter antenna in boring tool 26 at position k=1 with the boring tool at a depth D 1 . The depth at D 1 can be measured, for example, by a walk-over locator or using a tape-measure if the initial position of the boring tool has been exposed. Hence, the initial homing transmitter position becomes
[0000] X 1 =0 (1)
[0000] Z 1 =−D 1 (2)
[0045] In an embodiment where the origin of the coordinate system is defined at point 42 , where the boring tool enters the enters the ground, the origin of the coordinate system is at the center of the transmitter antenna with D 1 =0.
[0046] Homing receiver position coordinates designated as X hr ,Z hr can be measured before homing begins. In addition, the average length of drill rods L R can determined for use in embodiments where the drill rig does not monitor the length of the drill string. For purposes of the present description, it will be assumed that drill rods are to be counted and that homing command determinations are made on a rod by rod basis such that the average drill rod length is relevant. The user can specify the depth of the target D T below the homing receiver so that target position coordinates, designated as X T ,Z T , can be obtained from
[0000] X T =X hr (3)
[0000] Z T =Z hr −D T (4)
[0047] During homing, flux components are measured using antenna 262 of the homing receiver for use in conjunction with the measured pitch, designated as φ, of the boring tool at each k position. The homing system utilizes an estimate of pitch measurement uncertainty a σ φ and of the measurement uncertainties of the 2 fluxes in the vertical X,Z plane which are denominated as σ b X ,σ b Z , respectively. In addition, measurement uncertainties σ Z i ,σ X hr ,σ Z hr are utilized where σ Z 1 is the measurement uncertainty of depth Z 1 at position k 1 , the value σ X dr is the measurement uncertainty of the position of homing receiver 260 on the X axis, and the value σ Z hr is the measurement uncertainty of the position of homing receiver 260 on the Z axis. Note that σ X 1 =0 since X 1 =0 according to the definition above of the selected coordinate system. It should be appreciated that the various measurement uncertainties can be empirically obtained in a straightforward manner by evaluating and comparing repeat measurements of the quantity of interest. The uncertainty of locator position measurements is readily available from the manufacturer of distance measuring devices. Although the position of the homing receiver can be determined in any suitable manner, suitable handheld or tripod mounted laser devices are readily commercially available for measuring the homing receiver position coordinates. For example, the Leica Disto™ D5 can be used which has a range of over 300 feet and a built-in pitch sensor. In other embodiments, standard surveyor instrumentation can be used to determine the homing receiver position/coordinates prior to homing.
[0048] In one embodiment, the method is based on two types of equations, referred to as process equations and measurement equations. The following process equations are chosen where the dot symbol denotes derivatives with respect to arc length s along the axis of the drill rod or drill string:
[0000] {dot over (X)}=cos φ (5)
[0000] Ż=sin φ (6)
[0049] For vertical homing, the flux components b X ,b Z induced at the homing receiver are measured. They can be expressed in terms of transmitter position X,Z, homing receiver position X hr ,Z hr and pitchφ. This leads to the following measurement equation written in vector form as
[0000] {right arrow over (B)}= 3 x hr R −5 {right arrow over (R)}−R −3 {right arrow over (u)} (7)
[0000] where
[0000] {right arrow over ( B )}=( b X ,b Z )′ (8)
[0000] {right arrow over ( R )}=( X hr −X,Z hr −Z )′ (9)
[0000] R=|{right arrow over (R)}| (10)
[0000] {right arrow over ( u )}=(cos φ, sin φ)′ (11)
[0000] x hr ={right arrow over (e)}′{right arrow over (R)} (12)
[0050] Above, the prime symbol denotes the transpose of a vector.
[0051] Equations (5) and (6) are ordinary differential equations for the two unknown transmitter position coordinates X,Z. Vector Equation (7) can be written as two scalar equations for the flux components b X and b Z along the X and Z axes. It should be appreciated that these equations represent an initial value problem since Equations (5) and (6) can be integrated along arc length S starting from known initial values X 1 ,Z 1 at k=1. Equations (5), (6) and (7) couple flux measurements at the homing receiver to the transmitter position such that enhanced accuracy homing commands can be generated as compared to homing commands that are generated based solely on flux measurements, as in a conventional homing system.
Nonlinear Solution Procedures
[0052] The foregoing initial value problem can be solved using either a nonlinear solution procedure, such as the method of nonlinear least squares, the SIMPLEX method, or can be based on Kalman filtering. The latter will be discussed in detail beginning at an appropriate point below. Initially, however, an application of the SIMPLEX method will be described where the description is limited to the derivation of the nonlinear algebraic equations that are to be solved at each drill-path position. Details of the solver itself are well-known and considered as within the skill of one having ordinary skill in the art in view of this overall disclosure.
SIMPLEX Method
[0053] The present technique and other solution methods can replace the derivatives X, Z in Equations (5) and (6) with finite differences that are here written as:
[0000]
X
.
=
X
k
+
1
-
X
k
L
R
(
13
)
Z
.
=
Z
k
+
1
-
Z
k
L
R
(
14
)
[0054] Resulting algebraic equations read:
[0000] f 1 =X k+1 −X k −L R cos φ k =0 (15)
[0000] f 2 =Z k+1 −Z k −L R sin φ k =0 (16)
[0055] The flux measurement Equations (7-12) provide two additional algebraic equations written as:
[0000] f 3 =b X k+1 −3 x hr R k+1 −5 ( X hr −X k+1 )+ R k+1 −3 cos φ k+1 =0 (17)
[0000] f 4 =b Z k+1 −3 x hr R k+1 −5 ( z hr −Z k+1 )+ R k+1 −3 sin φ k+1 =0 (18)
[0056] Here, transmitter pitch and fluxes are measured at the (k+1) st position. The distance between transmitter and homing receiver is obtained from the corresponding distance vector which reads
[0000] {right arrow over (R)} k+1 =( X hr −X k+1 ,Z hr −Z k+1 )′ (19)
[0000] Furthermore, we use
[0000] R k+1 =|{right arrow over (R)} k+1 | (20)
[0000] {right arrow over (u)} k+1 =(cos φ k+1 , sin φ k+1 )′ (21)
[0000] x hr ={right arrow over (u)}′ k+1 {right arrow over (R)} k+1 (22)
[0057] Starting with the known initial values (Equations 1 and 2) at drill begin, the coordinates of subsequent positions along the drill path can be obtained by solving the above set of nonlinear algebraic equations (15-22) for each new tool position. The coordinates of position k+1 are determined iteratively beginning with some assumed initial solution estimate that is sufficiently close to the actual location to assure convergence to the correct position. One suitable estimate will be described immediately hereinafter.
[0058] An initial solution estimate is given by linear extrapolation of the previously predicted/last determined position to a predicted position. The linear extrapolation is based on Equations 5 and 6 and a given incremental movement L R of the homing tool from a k th position where:
[0000] ( X k+1 ) est =X k +L R cos φ k (23)
[0000] ( Z k+1 ) est =Z k +L R sin φ k (24)
[0059] Where the subscript (est) represents an estimated position. Application of the SIMPLEX method requires definition of a function that is to be minimized during the solution procedure. An example of such a function that is suitable in the present application reads:
[0000]
F
=
∑
p
=
1
4
f
p
2
(
25
)
[0060] As noted above, it is considered that one having ordinary skill can conclude the solution procedure under SIMPLEX in view of the foregoing.
Kalman Filter Solution
[0061] In another embodiment, a method is described for solving the homing command by employing Kalman filtering. The filter reduces the position error uncertainties caused by measurement minimizing the uncertainty of the vertical homing command in a least square sense thereby increasing the accuracy of the vertical homing command. The Kalman filter is applied in a way that couples flux measurements on a position-by-position basis with integration of pitch readings that are indicative of position coordinates in the X,Z plane, while accounting for error estimates relating to both flux measurement and pitch measurement.
[0062] It is worthwhile to note that a Kalman filter merges the solutions of two types of equations in order to obtain a single set of transmitter position coordinates along the drill path. In the present application, one set of equations (Equations 5 and 6) defines the rate of change of transmitter position along the drill path as a function of measured pitch angle. Equation (7) is based on the equations of a magnetic dipole inducing a flux at the homing receiver antenna. The Kalman filter provides enhanced homing commands by reducing the effect of errors in measuring fluxes, pitch, and homing receiver position.
[0063] The homing procedure can be initiated at a known boring tool position, as described above. Advancing the boring tool to the next location by one rod length provides an estimate of the new transmitter position that is limited to the X,Z plane by integrating measured pitch for known drill rod length increment. Consequently, this position estimate is improved by incorporating dipole flux equations. Accordingly, enhanced homing commands are generated responsive to both the flux measurements and the position of the boring tool in the vertical X,Z plane. This process is repeated along the drill path until the drill head has reached the target. It should be mentioned that the strength of the homing signal is generally initially weakest at the start of the homing procedure and increases in signal strength as the boring tool approaches the boring tool. The present disclosure serves not only to increase the accuracy of the homing signal but to increase homing range to distances that are unattainable in a conventional homing system for a given signal strength, as transmitted from the boring tool.
[0064] It is noted that the Kalman filter addresses random measurement errors. Therefore, fixed errors can be addressed prior to homing. For example, any significant misalignment of the pitch sensor in the boring tool with the elongation axis of the boring tool can be corrected. Such a correction can generally be performed easily by applying a suitable level such as, for example, a digital level to the housing of the boring tool and recording the difference between measured pitch and the pitch that is indicated by the pitch signal generated by the boring tool. Systematic error such as pitch sensor misalignment can be addressed in another way by using an identical roll orientation of the boring tool each time the pitch orientation is measured.
Nominal Drill Path
[0065] Assuming that the coordinates X k ,Z k are known for a current position of the boring tool whether by measurement of the initial position or by processing determinations on a position-by-position basis, an estimate for the next position of the boring tool can be obtained by linear extrapolation from k to k+1 for the incremental distance that is being used between adjacent positions. This estimate is a point on what is referred to herein as the nominal drill path, indicated by the superscript (*). In the present example, the incremental distance is taken as the average rod length, although this is not a requirement. The nominal drill path falls within the X,Z plane and ignores any out of plane travel of the boring tool. Hence, the coordinates for the estimated position become:
[0000] X* k+1 =X k +L R cos φ k (26)
[0000] Z* k+1 =Z k +L R sin φ k (27)
[0066] Here, the symbols L R ,φ k denote average rod length and boring tool transmitter pitch at position k, respectively. It is noted that L R can correspond to any selected incremental distance between positions and may even vary from position to position.
[0067] While drill path positions can be found in one way by integrating Equations (5) and (6) starting from a specified initial guess without making use of flux Equation (7), solution accuracy may suffer from the following errors:
[0000] Integration errors due to pitch measurement errors, especially at relatively long ranges between the homing receiver and the initial transmitter position,
Numerical integration errors, and
Modeling inaccuracy since process Equations (5) and (6) might serve only as an approximation for some drilling scenarios.
State Variables
[0068] The Kalman Filter adds correction terms δX,δZ to the nominal drill path so that the transmitter position coordinates become:
[0000] X k+1 =X* k+1 +δX k+1 (28)
[0000] Z k+1 =Z* k+1 +δZ k+1 (29)
[0069] The vector containing δX,δZ is denominated as the vector of state variables, given as:
[0000] {right arrow over (x)} =(δ X,δZ )′ (30)
[0070] The vector of state variables is governed by a set of state equations derived from Equations (5) and (6) by linearization, given as:
[0000] {right arrow over (x)} k+1 =Φ k {right arrow over (x)} k +{right arrow over (w)} k (31)
[0000] where
[0000] {right arrow over (w)} k =L R {right arrow over (G)} k δφ k (32)
[0000] Φ k =I (33)
[0000] {right arrow over (G)} k =(−sin φ k , cos φ k )′ (34)
[0071] Above, the vector {right arrow over (w)} k of Equation (19) is the process noise that depends on pitch measurement error and on vector {right arrow over (G)} k which in turn is a function of pitch. The covariance of {right arrow over (w)} k is the so-called discrete process noise covariance matrix Q k which plays an important role in Kalman filter analysis, given as:
[0000] Q k =cov ( {right arrow over (w)} k ) (35)
[0000] Q k =L R 2 {right arrow over (G)} k σ φ 2 {right arrow over (G)}′ k (36)
[0072] Even though Q k is defined analytically it could be manipulated empirically in order to increase solution accuracy for some applications. One convenient method to achieve this is to multiply Q k by the factor F E whose value is determined empirically by numerical experimentation. The best value of F E provides the most accurate predictions of the vertical homing command.
[0073] Linearization of the flux measurement equations about the nominal drill path results in the so-called observation equations, given in vector notation as:
[0000] {right arrow over (z)}=H{right arrow over (x)}+{right arrow over (ν)} b +{right arrow over (ν)} hr (37)
[0074] Application to Equations (7-12) provides the following details of vector {right arrow over (z)} and matrix H:
[0000] {right arrow over (z)} =( b X m −b X *,b Z m −b Z *)′ (38)
[0000] H= 3 x hr R −7 (5 {right arrow over (R)}{right arrow over (R)}′−R 2 I )−3 R −5 ( {right arrow over (R)}{right arrow over (u)}′+{right arrow over (u)}{right arrow over (R)} ′) (39)
[0000] x hr ={right arrow over (u)}′{right arrow over (R)} (40)
[0000] {right arrow over ( u )}=(cos φ, sin φ)′ (41)
[0000] {right arrow over (R)} =( X hr −X*,Z hr −Z *) (42)
[0000] R=|{right arrow over (R)}| (43)
[0075] Note that b* X ,b* Z are the fluxes induced at the homing receiver by the transmitter on the nominal drill path X*,Z*. These fluxes can be determined using Equations (7-12) with {right arrow over (R)}=(X hr −X*,Z hr −Z*)′. Fluxes b X m ,b Z m are the actual fluxes measured at the homing receiver with the boring tool transmitter in its actual position along the borehole, which can be yawed and/or positioned out of the X,Z plane.
[0076] The terms {right arrow over (ν)} b ,{right arrow over (ν)} hr represent vectors of flux measurement errors and homing receiver position errors, respectively. The observation error covariance matrix R M , also used by the Kalman filter loop, is given by:
[0000] R M =cov ({right arrow over (ν)} b +{right arrow over (ν)} hr ) (44)
[0000]
R
M
=
[
σ
b
X
2
0
0
σ
b
Z
2
]
+
H
[
σ
X
hr
2
0
0
σ
Z
hr
2
]
H
′
(
45
)
[0077] State variables {right arrow over (x)} and error covariance matrix P are initialized at the new position along the drill path by setting
[0000] {circumflex over ({right arrow over (x)} k+1 =(0,0)′ (46)
[0000] P k+1 − =P k +Q k (47)
[0078] Here, the superscript ( ) − indicates the last available estimate of P.
[0079] The process of updating P begins with P 1 at the initial homing position X 1 ,Z 1 . Its value is given as
[0000]
P
1
=
[
σ
X
1
2
0
0
σ
Z
1
2
]
(
48
)
[0080] The classical, well documented version of the Kalman filter loop is chosen as a basis for the current homing tool embodiment. It is made up of three steps:
[0081] Kalman gain is given as:
[0000] K=P − H ′( HP − H′+R M ) −1 (49)
[0082] Update state variables:
[0000] {circumflex over ({right arrow over (x)}={circumflex over ({right arrow over (x)} − +K ( {right arrow over (z)}−H{circumflex over ({right arrow over (x)} − ) (50)
[0083] Update error covariance matrix:
[0000] P =( I−KH ) P − (51)
[0084] Above, the symbol {circumflex over ({right arrow over (x)} denotes a state variables estimate.
[0085] Equations (36-38) define a standard Kalman filter loop, for instance, as documented by Brown and Hwang, “Introduction to Random Signals and Applied Kalman Filtering”, 1997.
Homing Commands
[0086] The vertical homing command in this embodiment is given by the vertical distance between transmitter and target:
[0000] Δ Z=Z−Z T (52)
[0087] The horizontal homing command is defined as the ratio of horizontal fluxes measured at the homing receiver.
[0000]
Δ
Y
=
b
Y
m
b
X
m
(
53
)
[0088] Attention is now directed to FIG. 4 which illustrates one exemplary embodiment of a method according to the present disclosure, generally indicated by the reference number 300 . The method begins at step 302 in which various set-up information is provided. It is noted that these items have been described above insofar as their determination and the reader is referred to these descriptions. The information includes the position of the homing receiver, the depth of the target, the average length of the drill rods to be used in an embodiment which relies on the drill rod length as an incremental movement distance; the initial transmitter depth; measurement uncertainties of pitch readings, flux measurements, homing receiver position and the initial transmitter depth; and the pitch bias error, if any.
[0089] At 304 , for the current position of the boring tool, the pitch is measured as well as fluxes at the homing receiver using antenna 262 . Note that the boring tool can be oriented at an identical roll orientation each time a pitch reading is taken if such a technique is in use for purposes of compensating for pitch bias error.
[0090] At 306 , the selected nonlinear solution procedure such as, for example, the aforedescribed Kalman filter analysis is performed for the current position of the boring tool.
[0091] At 308 , the homing commands are determined based on the nonlinear solution procedure and the homing commands are displayed to the user.
[0092] At 310 , a determination is made as to whether the boring tool has arrived at the target position. If not, the boring tool is moved by step 312 to the next position and the process repeats by returning to step 304 . If, on the other hand, the determination is made that the boring tool has arrived at the target, the procedure ends at 314 .
[0093] The homing commands can be displayed, for example, as seen in FIG. 5 where the objective is to minimize ΔY,ΔZ when the target is approached. In particular, a screen shot of one embodiment of the appearance of display 266 is shown having a crosshair arrangement 400 with a homing pointer 402 . In the present example, the boring tool should be steered down and the left by the operator of the system according to homing pointer 402 . That is, pointer 402 shows the direction in which the boring tool should be directed to home in on the homing receiver. The position of the homing indicator on the display is to be established by the determined values of ΔY and ΔZ, as described above. When homing indicator 402 is centered on cross-hairs 404 , the boring tool is on course and no steering is required.
[0094] Numerical simulations of vertical homing, according to the disclosure above, are now presented assuming pitch, fluxes and homing receiver position can be measured with the following accuracies:
[0000] σ φ =0.5 deg (54)
[0000] σ b X =2.4 e −6 ft −3 (55)
[0000] σ b Z =2.4 e −6 ft −3 (56)
[0000] σ X hr =0.1 ft (57)
[0000] σ Z hr =0.1 ft (58)
[0095] The chosen initial position accuracy depends on the location where homing begins.
[0000] σ X 1 =0 for X 1 =0 (59)
[0000] σ Z 1 =0 for Z 1 =0 (60)
[0000] or
[0000] σ Z 1 =0.1 ft for Z 1 =−D 1 (61)
[0096] Referring to FIGS. 6 a - 6 d , a numerical simulation is provided based on the Kalman filter embodiment described above and the accuracies set forth by Equations (54-61), as applicable. FIG. 6 a is a plot, in elevation, showing the X, Z plane and an exact path in the plane that is indicated by the reference number 600 . The homing procedure is initiated at coordinates (0,−10) and target T is located at coordinates (100,−4). The equation of this exemplary drill path is given as:
[0000] Z ex =−10+(6 e −4) X ex 2 , ft (62)
[0097] Here the subscript (ex) stands for “exact.” The example represents homing with a 100 foot range of effective vertical homing and a ten foot average drill rod length. It should be appreciated that this drill path is representative of a homing distance that is generally well beyond the standard range of a conventional homing system at the start of drilling. The range of a conventional homing system is typically about 40 feet with a typical transmitter and a typical receiver. FIG. 6 b is another plot of the X, Z plane showing a plot 602 of the value of the vertical homing command. It should be appreciated that the magnitude of the homing command controls the amount of steering that is needed. Thus, the magnitude of the homing command starts decreasing significantly at around X=40 feet and has the value zero at X=100 feet, where the boring tool arrives at the target. FIG. 6 c shows a plot of the value of X error 604 along the length of the drill path. The X error is the difference between the actual position of the boring tool along this axis and the determined position of the boring tool along the X axis. FIG. 6 d shows a plot of Z error 606 along the length of the drill path. The Z error is the difference between the actual position of the boring tool along this axis and the determined position of the boring tool along the Z axis. It is noted that a negative going peak 610 is present in plot 606 at X=60 feet, representing a maximum vertical position error of approximately 7 inches at a distance equivalent to 4 rod length laterally away from the target. This distance provides sufficient steering reserves to accurately reach the target. The X position error along the drill path is less than 1 inch. Note in this example that homing started at a depth of 10 ft. At X=100 feet, the Z error value is near zero.
[0098] Referring to FIGS. 7 a - 7 d , another numerical simulation is provided based on the Kalman filter embodiment described above and the accuracies set forth by Equations (54-61), as applicable. FIG. 7 a is a plot, in elevation, showing the X,Z plane and an exact path in the plane that is indicated by the reference number 700 . The homing procedure is initiated at coordinates (0,0) and target T is located at coordinates (80,−10). Again, at the incept of drilling, this example illustrates a range that is generally well beyond the range that is available in a conventional homing system. The equation of this exemplary drill path is given as:
[0000] Z ex =−0.25 X ex +0.0015625 X ex 2 (63)
[0099] Where the subscript (ex) again stands for “exact.” The example represents homing with an 80 foot range of effective vertical homing and a five foot average drill rod length. FIG. 7 b is another plot of the X, Z plane showing a plot 702 of the value of the vertical homing command. As is the case in all of the examples presented here, the magnitude of the homing command controls the amount of steering that is needed. Thus, the magnitude of the homing command starts decreasing significantly at around X=50 feet and has the value zero at X=80 feet, where the boring tool arrives at the target. FIG. 7 c shows a plot of the value of X error 704 along the length of the drill path. It is noted that the X error is less than approximately 2 inches for the entire length of the drill path. FIG. 7 d shows a plot of Z error 706 along the length of the drill path. It is noted that a negative going peak 710 is present in plot 706 at X=48 feet representing a maximum Z error of about 6 inches at around 30 feet from the target. At X=80 feet, the Z error value is near zero.
[0100] The previous examples assume that during the homing process the transmitter moves in the vertical X,Z plane and that any three-dimensional effect on vertical homing commands is negligible. In the next example, it will be shown that homing commands remain accurate even when the transmitter leaves the vertical plane and/or yaws with respect to the vertical plane. The lateral offset may reduce lateral homing effectiveness at initial, greater range from the target but lateral effectiveness improves when the transmitter approaches the target, as will be seen.
[0101] Turning to FIG. 8 a - d , a three-dimensional test case will now be described. FIG. 8 a illustrates a plot of a horizontal drill path 800 that is added to the vertical drill path of FIG. 6 a and given by Equation (49). A ten foot average drill rod length is used in the present example. The lateral drill path is given by:
[0000] Y ex =0.2 X ex −(2 e −3) X ex 2 (64)
[0102] The three-dimensional effect is mainly due to changes in transmitter yaw and to the lateral offset resulting in slightly different fluxes measured by the homing receiver antennas. Minor changes of measured pitch can also contribute to this effect. The lateral offset reaches a maximum of five feet at a point 802 in plot 800 . FIG. 8 b is a plot of the vertical homing command 806 as further influenced by the lateral deviation in FIG. 8 a . For purposes of comparison, homing command plot 602 of FIG. 6 b is shown as a dashed line. It is noted that the difference between plots 602 and 806 is not viewed as significant in terms of overall results of the homing procedure. FIG. 8 c illustrates the Z error 810 along the X axis which includes the effects of yaw and lateral deviation from the X, Z plane with Z error plot 606 of FIG. 6 d shown as a dashed line for purposes of comparison. Even for a significant 5 foot lateral deviation, as seen in FIG. 8 a , the accuracy of the vertical homing command is near that of the two-dimensional test case of FIG. 6 a , as is evidenced by FIG. 8 c . That is, the maximum Z error is approximately 7 inches in each case but the three-dimensional effect of the lateral transmitter offset, shown in FIG. 8 a , causes the maximum Z error to move closer to the target. Thus, the present example confirms that homing according to the present disclosure is highly effective with relatively large amounts of yaw and lateral deviation from the X,Z plane. Accordingly, a relatively reduced accuracy of the horizontal component of the homing command at long range is confirmed by this example as acceptable.
[0103] FIG. 9 illustrates the vertical homing command, ΔZ versus X based on the drill path depicted in FIG. 6 a . A first plot 900 , shown as a dotted line, illustrates the vertical homing command for the exact drill path (see also, plot 602 of FIG. 6 b ). A second plot 902 , shown as a dashed line, illustrates the vertical homing command derived based on a conventional system which generates the homing command based solely on flux measurements. A third plot 904 , shown as a solid line, illustrates the homing command based on the use of the Kalman filter. It should be appreciated that the homing receiver is located at X=100 feet such that positions to the left in the view of the figure are relatively further from the homing receiver. It can be seen that the Kalman filter plot 902 and the conventional plot 904 agree well with the exact homing command plot 900 when the transmitter is within 40 feet or so of the homing receiver. That is, the value of X is greater than 60 feet in the plot. At larger distances from the homing receiver (i.e., below X=60 feet, the conventional system becomes increasingly unreliable and eventually fails to provide any meaningful homing guidance, for example, proximate to X=40 feet. Kalman filter plot 904 , however, closely tracks the exact homing command values of plot 900 along the entire drill path, even at greater distances from the homing receiver, including proximate to X=40 feet at which the conventional system is essentially unusable. It should be appreciated that attempting to use the conventional system at long range would result in dramatically oversteering the boring tool upward.
[0104] In view of the foregoing, it should be appreciated that a homing apparatus and associated method have been described which can advantageously use a measured parameter in the form of the drill string length in conjunction with measured flux values to generate a vertical homing command. Further, a nonlinear solution procedure can be employed in order to remarkably enhance vertical homing command accuracy and homing range as compared to conventional homing implementations that rely only on flux measurements.
[0105] While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.
|
A boring tool that is moved by a drill string to form an underground bore. A transmitter transmits a time varying dipole field as a homing field from the boring tool. A pitch sensor detects a pitch orientation of the boring tool. A homing receiver is positionable at a target location for detecting the homing field to produce a set of flux measurements. A processing arrangement uses the pitch orientation and flux measurements with a determined length of the drill string to determine a vertical homing command for use in controlling depth in directing the boring tool to the target location such that the vertical homing command is generated with a particular accuracy at a given range between the transmitter and the homing receiver and which would otherwise be generated with the particular accuracy for a standard range, different from the particular range. An associated system and method are described.
| 4
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of international application number PCT/EP2005/003482, filed on Apr. 2, 2005, that claims the benefit of German patent application number 10 2004 017 796.1, filed on Apr. 5, 2004, both of which are incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a spacer for use in filter modules comprising two or more layers of a filter material, with a spacer layer being disposed between two successive layers of filter material.
[0003] Filter modules of this type are used, in the form of spiral wound-type modules or stacked modules, for a wide range of filtration tasks, for example for the treatment of industrial waste water, the treatment of industrial process water, the treatment of leachate from landfills or for desalination of seawater.
[0004] Hitherto, dimensionally stable plastic disks with a multiplicity of punctiform elevations or webs, on which filter cushions come to bear, on their surface have been used as spacers in stacked modules. A volume is then available between the surface of the disks and a filter cushion for the flow over the filter material. The disks have apertures, so that the medium flowing over them can flow over a plurality of filter cushions in series. These stacked modules operate on the basis of the principle of open-passage technology, i.e. the medium supplied can flow onto substantially the entire surface area of the filter material, and there are no or only minimal flow obstacles in the direction of flow. The open-passage technology means that stacked modules are not susceptible to fouling, but they do have a relatively low packing density, with the result that the module costs based on the filter area available are higher than in the case of spiral wound-type modules, for example.
[0005] Unlike stacked modules, spiral wound-type modules have hitherto been constructed in such a way that the spacer is constructed as a flexible grid or mesh structure. The spacers are formed in such a manner that webs which are in contact with the filter material form obstacles in the direction of flow, at which obstacles spaces where the through-flow is reduced and deposits accumulate are formed. The deposits of constituents of the medium that form are referred to as fouling. Furthermore, in conventional modules the webs form barriers which restrict the extent to which the modules can be cleaned, since sediment removed during cleaning cannot be discharged from the module on account of the obstacles. Furthermore, the surface area of the filter material is not fully utilized, since no filtration takes place at the bearing locations. On the other hand, spiral wound-type modules have a relatively high packing density and are less expensive than stacked modules, based on the filter area available.
[0006] Spacers for spiral wound-type modules are described, for example, in DE 100 51 168 A1.
BRIEF SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to propose spacers for filter modules which have the advantages of open-passage technology and at the same time allow high packing densities, similar to those achieved with conventional spiral wound-type modules. According to the invention, this object is achieved by a spacer as described in claim 1 .
[0008] To avoid fouling at the spacer, it is crucial that spaces through which the flow is reduced and in which deposits can accumulate be avoided as far as possible. As seen in the direction of flow of the medium being filtered, the spacer layer should substantially not have any points of contact with the surface of the filter material, so that the tendency to fouling is minimized. This is made possible by the structure of the spacers in accordance with the invention. The spacers according to the invention can be used for the production of both stacked and spiral wound-type modules.
[0009] The advantages achieved according to the invention in detail are as follows:
the substantial to complete absence of dead zones minimizes the susceptibility to fouling; the unimpeded flow through the feed passage improves the cleanability of the filter module, since it is possible to discharge sediment; it is possible to treat water carrying relatively high levels of solids which it has not hitherto been possible to treat using spiral wound-type modules; it is possible to reduce pressure losses by using optimized incoming flow conditions; the promotion of turbulence makes it possible to reduce the concentration polarization; it is possible to configure filter modules with an increased packing density compared to standard stacked-plate modules.
DETAILED DESCRIPTION OF THE INVENTION
[0016] It is preferable for the web regions which are responsible for supporting the filter material on the spacer to be configured in the form of straight fins. In this case, it is generally possible to provide for the fins to extend over the entire length or the entire extent of the filter material, in particular the membrane, in particular if the webs are disposed substantially parallel to the direction of flow of the fluid being filtered.
[0017] The fins may be provided on the same web regions on the upper and lower sides of the spacer layer, so as to form a multiplicity of parallel flow passages.
[0018] One alternative consists in configuring the web regions which bear against the surface of the filter material in the form of punctiform or substantially punctiform regions, i.e. with a small area compared to the extent of the grid or mesh structure.
[0019] By way of example, it is possible to provide for the punctiform supporting regions of the webs to be formed at junction points of the webs.
[0020] All other regions of the grid structure then do not lead to contact with the surface regions of the filter materials and allow the fluid to flow through substantially unimpeded. This minimizes volumes with reduced flow through them as far as possible.
[0021] In a further alternative, the filter material layers are supported on the upper side of the spacer layer at one web region and on the lower side of the spacer layer at another web region. This allows flow onto the spacer layer even with web regions that are continuous in form, with the direction of flow forming an acute angle with the preferred directions.
[0022] In a further preferred embodiment, substantially all the webs are formed parallel to the preferred directions if they comprise web regions which serve to bear against the surfaces of the filter materials.
[0023] One of the preferred directions is preferably oriented substantially parallel to the direction of flow of the fluid being filtered.
[0024] Depending on the particular application, a more or less turbulent flow may be desired in the filter module. By way of example, turbulence is in some cases undesirable in applications in the food industry in which the concentrate represents the product, in order thereby to maintain the quality of the product.
[0025] On the other hand, in waste water applications, it is often desirable for the flow over the membrane to be as turbulent as possible, in order to further reduce the risk of fouling and scaling.
[0026] Webs or web regions which do not bear against the surface of the filter material and are kept at a distance therefrom are in certain applications preferably noncircular in cross section, i.e. in particular of an oblate shape, so that they form a minimal resistance to the incoming flow of the fluid.
[0027] For other applications, these or other web regions may preferably be disposed and/or formed in such a way that they produce regions of turbulence, thereby disrupting laminar flows at the membrane surface, with the result that fouling on the surface of the filter material can be avoided and concentration polarization at the surface of the filter material can also be broken up or avoided.
[0028] Concentration polarization is the regional increase in the concentration of substances in the region of the membrane surface, caused by the solvent being transported through the membrane.
[0029] Overall, the webs are preferably connected to one another and configured in such a way that they form flow channels whose cross section substantially approaches the shape of rectangles. The bearing surface of the web regions which bear against the surfaces of the filter materials will be as small as possible, in order to cover the minimum possible amounts of the filter material surface area available.
[0030] However, the bearing surface as a whole must not be too small, to avoid damage to the filter material surface, which could otherwise be caused by loads resulting from pressure fluctuations during the filtration operation. A cross section through the flow passages which is as far as possible rectangular ensures that the flow velocity is substantially uniform, as seen over the cross section of the passages, so that as much as possible of the available filter material surface area can be utilized uniformly and volumes with a reduced flow through them are avoided.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0031] These and further advantages of the invention are explained in more detail below with reference to the drawing, in which, in detail:
[0032] FIG. 1 shows a sectional view through a first embodiment of the filter module of the present invention;
[0033] FIG. 2 shows a plan view of the spacer according to the invention of the filter module shown in FIG. 1 ;
[0034] FIG. 3 shows an enlarged sectional view of a detail from FIG. 2 ;
[0035] FIG. 4 shows a sectional view through a further embodiment of the filter module according to the invention;
[0036] FIG. 5 shows a plan view of the spacer according to the invention of the filter module shown in FIG. 3 ;
[0037] FIG. 6 shows an enlarged sectional view of a detail from FIG. 5 ;
[0038] FIG. 7 shows a sectional view through a further embodiment of a filter module of the present invention;
[0039] FIG. 8 shows a plan view of the spacer according to the invention of the filter module shown in FIG. 7 ;
[0040] FIG. 9 shows an enlarged sectional view through a detail from FIG. 8 ;
[0041] FIG. 10 shows a sectional illustration through a further embodiment of the filter module according to the invention;
[0042] FIG. 11 shows a plan view of the spacer according to the invention from FIG. 10 ; and
[0043] FIG. 12 shows an enlarged sectional view of a detail from FIG. 11 .
[0044] FIG. 1 shows a filter module, which is denoted overall by reference numeral 10 and comprises a first layer 12 of a filter material and a second layer 14 of the filter material, which are held spaced apart from one another by a spacer 16 disposed between them. The filter material layers 12 and 14 may consist of different filter materials, and may in particular also be in the form of membranes.
[0045] A filter cushion can be constructed from two layers of filter material with a spacer between them for discharging permeate. The three layers are welded or adhesively bonded to one another at the outer edges. The cushion shape and the number of joined sides depend on the desired filter module shape.
[0046] The spacer 16 (also referred to below as a spacer layer) is substantially assembled from webs to form a gridlike structure, with the webs disposed in two directions and connected to one another via junction points. In particular, in this case there are webs 18 which are disposed parallel to the direction of flow of a fluid being treated and which are held spaced apart from one another and connected to one another by means of transverse webs 20 . On their surfaces facing upward and downward, the webs 18 have fins 22 and 24 , which serve on the one hand to support the filter material layer 12 and on the other hand to support the filter material layer 14 . They therefore include first web regions which define the bearing surfaces for the filter materials.
[0047] The transverse webs 20 , by contrast, maintain a spacing both from the surface of the filter material layer 12 and from the surface of the filter material layer 14 and thereby avoid zones through which the flow is reduced, allowing the fluid being filtered to flow through substantially unimpeded. These represent the second web regions.
[0048] FIG. 2 provides a further, more detailed illustration of the mesh structure of the spacer layer 16 , providing a clear and detailed illustration of the rectangular grid structure of the spacer layer 16 . The webs 18 , which continue endlessly, carry the abovementioned fins 22 , which form a narrow bearing surface for the filter material layer 12 , on their upper side. The transverse webs 20 hold the webs 18 spaced apart from one another and are in each case set back from the plane formed by the bearing surfaces of the fins 22 .
[0049] A view from below is not shown here, since such a view would be substantially identical to the top view illustrated here.
[0050] Finally, FIG. 3 shows, in the form of a detail view, a number of variants a, b, c and d of a possible cross section through the webs 20 ; if noncircular webs 20 are used, depending on the particular application, the disposition of the webs opposite to the direction of flow of the fluid being filtered is selected in such a way that the area facing the incoming flow is as small as possible, or is selected in such a way that regions of turbulence are produced in the flow of the fluid. In the former case, the resistance to incoming flow is minimized, whereas in the latter case possible concentration polarization is inhibited.
[0051] In the latter case, the noncircular webs 20 will be disposed in such a way (cf. in particular variants a) and d)) that the liquid is diverted in one direction or the other by the webs 20 , so that laminar flows at the filter material surfaces are broken up. This allows deposits on the surface of the filter material to be reduced or even avoided altogether and also makes it possible to counteract or avoid concentration polarization at the surface of the filter material.
[0052] A further variant of a filter module according to the invention is illustrated in FIG. 4 . The filter module 30 illustrated in FIG. 4 is of similar construction to the filter module 10 shown in FIG. 1 . In this module, a first filter material layer 32 and a second filter material layer 34 are held spaced apart from and substantially parallel to one another by a spacer layer 36 . The grid or mesh structure of the spacer layer 36 is once again constructed from longitudinal and transverse webs 38 and 40 , respectively, resulting in a rectangular structure.
[0053] First web regions 42 , which above and below the plane formed by the webs 38 and 40 carry studs 44 and 46 , against which one or other filter material layer 32 or 34 then comes to bear, are provided at the junction points of the longitudinal and transverse webs 38 , 40 .
[0054] It can be seen from the plan view of the spacer layer 36 presented in FIG. 5 that the bearing points of the studs 44 (and this also applies to the downwardly facing studs 46 ) are relatively small, so that a maximum clear surface area of the filter material layers 32 and 34 , respectively, results. Therefore, substantially almost all the web regions count as second web regions, which maintain a spacing from the filter material layers 32 and 34 .
[0055] Once again, various possibilities are available for the configuration of the transverse webs 40 , and these possibilities are illustrated as variants a, b, c and d in FIG. 6 . The statements which have been made in connection with the filter module 10 apply once again with regard to the selection of the geometry of the cross section of the transverse webs 40 and the orientation thereof.
[0056] The remaining form of the longitudinal webs 38 is substantially independent of the shape of the transverse webs 40 , in particular including in cross section. In this case too, as can be seen for example from FIG. 4 , it is possible to provide an elliptical cross section, so that on the one hand the stability of the grid structure is maintained, but on the other hand the maximum possible spacing of these webs too from the surfaces of the filter material layers 32 and 34 is maintained. This ensures that even in the surface regions of the filter material layers 32 and 34 , between which the longitudinal webs 38 are disposed, there are no small volumes in which deposits could occur, associated with subsequent fouling.
[0057] FIGS. 7 to 9 describe a further variant of the present invention, the basic structure of which is similar to the embodiment shown in FIGS. 1 to 3 .
[0058] The embodiment shown here relates to a filter module 50 in which a first filter material layer 52 and a second filter material layer 54 are held parallel to and at a spacing from one another by a spacer layer 56 disposed between them. The spacer layer 56 is once again formed by longitudinal webs 58 and transverse webs 60 .
[0059] As in the embodiment shown in FIGS. 1 to 3 , in the embodiment of a filter module shown here, the spacer 56 is constructed from continuous longitudinal webs 58 , which are lined up rectilinearly next to one another and carry fins 62 , 64 at their upper and lower sides, as can be seen most easily from FIG. 8 . They represent first web regions which define the bearing surfaces for the filter materials. In the filter module shown here in FIGS. 7 to 9 , the transverse webs 60 of the spacer are disposed differently compared to the embodiment of the filter module shown in FIGS. 1 to 3 . These transverse webs 60 do not run substantially parallel to the surfaces of the filter material layers 52 and 54 , but rather are disposed running at an angle to these surfaces and connect two longitudinal webs 58 disposed parallel to one another, linking to a fin 64 located at the bottom and ending in a fin 62 located at the top, of the adjacent longitudinal web 58 , or in the reverse orientation. The transverse web 60 located downstream as seen in the direction of flow will preferably have precisely the reverse form of linking between the two longitudinal webs 58 running next to one another, so that in the view illustrated in FIG. 7 the transverse webs as it were cross one another. This results in a particularly effective disruption, so that deposits or concentration polarization can be avoided at the surface of the filter material layers. In this exemplary embodiment, the transverse webs form the second web regions.
[0060] FIG. 9 once again shows possible modifications a, b, c and d of the cross sections of the transverse webs 60 , and the comments made with regard to these different cross sections correspond to what has already been stated in connection with FIG. 3 .
[0061] Finally, FIGS. 10 to 12 show a further embodiment of the present invention, with a structure similar to that shown in FIGS. 4 to 6 .
[0062] The filter module 70 illustrated once again comprises two filter material layers 72 and 74 , which are held parallel to and spaced apart from one another by a spacer layer 76 . Similarly to the embodiment shown in FIGS. 4 to 6 , both the longitudinal webs and the transverse webs maintain a spacing from the surfaces of the filter material layers 72 and 74 . The longitudinal webs 78 and the transverse webs 80 (second web regions) are connected to one another via junction points 82 , at which studs 84 and 86 for punctiform support of the filter material layers 72 and 74 (first web regions) are formed on the upper and lower sides of the spacer layer. As in the embodiment shown in FIGS. 6 to 9 , the transverse webs 80 run obliquely from the bottom upward, i.e. they connect a stud 86 at a junction point of a longitudinal web 78 to a stud 84 located above it of an adjacent longitudinal web 78 or vice versa, so that in the plan view shown in FIG. 10 the transverse webs 80 located behind one another as it were cross one another.
[0063] FIG. 12 once again shows possible variants of the cross section of the transverse webs 80 , comprising variants a, b, c and d, which have already been discussed in detail in connection with FIG. 3 .
Exemplary Embodiment
[0064] When the spacers according to the invention are used in membrane technology for the treatment of industrial process water, the main problem is often a high risk of fouling and scaling on the membrane as a result of organic and inorganic constituents of the water. In this context, it is an essential condition for use of a membrane filter that the module can be cleaned. Consequently, the use of spiral wound-type modules according to the prior art is eminently conceivable for relatively unpolluted water. The cleanability of the membrane is improved when using a spacer according to the invention, for example as shown in FIG. 1 . Moreover, the transverse web configuration shown in FIG. 3 a realizes flow guidance which reduces the concentration polarization and therefore the risk of blockages. A thickness of the spacer or the spacing of the bearing surfaces, which is defined by the spacer, of from 1 to 2 mm combined with a ratio of the heights of the second and first web regions, measured in the direction of the spacing, of from 1:2 to 1:4 is conceivable here depending on the degree of contamination of the untreated water.
|
Spacers for filter modules which have the advantages of open-channel technology and which at the same time allow high packing densities, similar to those achieved with conventional spiral wound-type modules, are disclosed wherein the spacer is disposed between two layers of a filter material and comprises a sheet material having a gridlike structure, and having upper and lower surfaces defining an upper and lower bearing face for the layers of filter material, the sheet material consisting of a large number of webs interconnected at junction points, of which webs a first portion is disposed parallel to a first preferred direction and a second portion is disposed parallel to a second preferred direction intersecting the first preferred direction, and at least some of the webs have first web regions, which extend to the upper and/or lower bearing face(s), and at least a further portion of the webs has second web regions which are spaced from the upper and lower bearing faces, the second web regions extending over substantially the entire length of those webs.
| 8
|
[0001] This application is a continuation-in-part of U.S. application Ser. No. 11/066,678 filed on Feb. 25, 2005, which is a continuation-in-part of U.S. application Ser. No. 10/459,868 filed on Jun. 12, 2003, now abandoned, which is a continuation-in-part of U.S. application Ser. No. 09/885,843 filed Jun. 20, 2001, now abandoned.
FIELD OF THE INVENTION
[0002] This invention relates to dwelling framing members, and in particular, to an attachment locking tab and opening which is used to attach one stud to another in such members by having the tab and its corresponding knock out positioned onto the metal stud via computer in accordance with the layout plans of the structure that is to be formed.
BACKGROUND OF THE INVENTION
[0003] Structural members are frequently made of metal, as it has advantages over wooden structural members. Compared to wood, metal is insect proof, fire proof, and has high uniformity and strength. However, its use is limited due to high cost, erection problems, and handling difficulties. U.S. Pat. No. 5,315,804, issued to Attalla, addresses some of these concerns. The patent discloses an improved metal framing member (STRONG STUD) that utilizes stiffening sections to enable a lighter gauge of metal to be used. The framing member also features embossed surfaces that facilitate fastening using standard self-tapping fasteners. Safety edges are provided to eliminate the sharp edge problem of handling metal framing members.
[0004] In addition to the above concerns, a framing member often must be provided with a chase to allow wiring or other objects to pass through the member. Introducing this chase after the framing member has been fabricated, as well as clipping or attaching the wiring to the member, can be tedious and time consuming. The patent mentioned above does not address this concern.
[0005] U.S. Pat. No. 5,943,838, issued to Madsen et al. on Aug. 31, 1999, discloses the use of a bendable tab which must be bent on the job by the metal stud installer. The use of the STRONG STUD taught in the '804 patent which utilizes heavy gauge, high strength material would make accurate and effective bending by the installer costly and difficult. Further, manual bending for even heavier gauge material that might be necessary in certain construction environments would be impossible.
[0006] Further, Madsen et al. teaches the use of a tab that is substantially less than that of the opening or knock-out. However, the Madsen et al. knock-out opening is substantially greater than the size of the tab which weakens the stud and potentially can cause buckling or torsion problems. Nor does Madsen et al. disclose or suggest the use of pre-punched pilot holes but instead relies solely on the use of self-tapping screws to connect the tab to another structure.
[0007] Therefore, what is needed is an improved metal framing member that includes a manufactured locating tab that is suitable for all metal studs, irrespective of the gauge of the metal, that can be placed at predetermined positions within the stud to serve to locate the attachment of other studs, has a knock-out opening that is substantially the same size as the size of the tab, that has pre-formed pilot holes for simplifying the installation of standard screw fasteners, and can serve as a preformed chase and a means of clipping objects passing through the chase to the member. Further, the use of a locking tab that enables one stud to be attached to a track member which can serve as a plate, header, footer, etc. without the need for additional fastening is also needed. A metal framing member including such a chase, locking tabs, that is low cost and can be handled safely is not found in the prior art.
SUMMARY OF THE INVENTION
[0008] The present invention is a metal framing member including at least one manufactured locking tab. The framing member has a substantially rectangular cross-section. Preferentially, at least two stiffeners run longitudinally along the metal framing member. Two locking tabs are punched out of the bottom portion between the two stiffeners. The locking tabs resulting from the punched out section of the framing member have an angled locking guide which serves to assist the locking tabs to be mated to corresponding punched out tab openings in a slotted tab punched out of a track meant to be attached to said framing member. Once the framing member locking tab is slid over its mating slotted tab so that tab openings are aligned with the locking tabs, the framing member is locked into place along the track. Additional locking tabs are optionally provided on each leg of the framing member to enable the framing member to be more securely attached to the track member. The tab openings that engage by locking tabs on the framing member can be either round or rectangular. Also, rather than provide another tab arrangement on the legs of the framing member, an opening that matches a mating opening in the track member can be pinned together using press pins well known in the art. Each locking tab assembly on the framing member and its corresponding track member is made at the factory using computer software to accurately match each position in accordance with the building design. Thus, the two parts can be put together securely and quickly without the use of screws, bolts or other fasteners.
[0009] Therefore, it is an aspect of this invention to provide an improved metal stud framing member.
[0010] It is another aspect of the invention to provide a framing member with a locking tab assembly that will mate with a locking tab assembly on a track or channel member.
[0011] It is a further aspect of the invention to provide a metal framing member with a receiving opening for a locking tab that is preferably rectangular shaped.
[0012] It is a further aspect of the invention to provide a metal track channel member with a receiving opening for a locking tab that is circular shaped.
[0013] It is still another aspect of the invention to provide a metal stud and corresponding track member that can be attached together without the use of screws, bolts or other fasteners well known in the art.
[0014] Another aspect of the invention is to provide a metal framing member and track member that has computer generated tabs to enable the two parts to mate together accurately and easily.
[0015] Another aspect of the invention is to provide a metal framing member and track member that can also be locked with a press pin through openings in the respective members.
[0016] Still another aspect of the invention is to provide a metal framing and corresponding track member that has accurate and dependable fixed locations to eliminate installation errors and increase the productivity of the framing process.
[0017] Still another aspect of the invention is to provide a metal stud framing member that has a punched locking tab having an angled material guide so that the metal framing member will easily snap over the mating locking tab openings on the track member.
[0018] These aspects of the invention are not meant to be exclusive and other features, aspects, and advantages of the present invention will be readily apparent to those of ordinary skill in the art when read in conjunction with the appended claims and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is an isometric view with a partial cut away view of the stud framing member showing one manufactured layout locating tab.
[0020] FIG. 2 is a detail showing the knock out opening that can be used as a chase in the framing member.
[0021] FIG. 3 is a top view of the tab.
[0022] FIG. 4 is a cross sectional view of the framing member illustrating the stiffeners used in the preferred embodiment.
[0023] FIG. 5 is a cross sectional view of another embodiment of the framing member without the stiffeners.
[0024] FIG. 6 is still another alternative embodiment of the framing member showing a plurality of manufactured layout locating tabs.
[0025] FIG. 7 is a detailed view of one tab positioned within the framing member shown in FIG. 6 .
[0026] FIG. 8 is cross sectional view of the tab within the framing member shown in FIG. 6 .
[0027] FIG. 9 is another embodiment of manufactured layout locating tab shown in the framing member depicted in FIG. 6 .
[0028] FIG. 10 is a detailed view of the tab embodiment shown in FIG. 9 .
[0029] FIG. 11 is a cross sectional view of the alternative embodiment of the tab.
[0030] FIG. 12 is front view of a typical wall that is constructed with framing members in accordance with the invention.
[0031] FIG. 13 illustrates a stiffening member that is inserted through the knock out opening of the framing member and attached to the tab provided via the knock out.
[0032] FIG. 14 shows a typical stress that may be constructed using the framing members in accordance with the invention.
[0033] FIG. 15 illustrates that the manufactured layout locating tab may be positioned anywhere on the framing member including the end.
[0034] FIG. 16 is an isometric view of locking tabs being used to connect a stud with a track channel in accordance with the invention.
[0035] FIG. 17 is a detailed isometric view of the preferred embodiment of the locking tab that is used on a stud.
[0036] FIG. 18 is a front detailed view of the locking tab shown in FIG. 17 .
[0037] FIG. 19 is a detailed cross sectional view across section 4 - 4 shown in FIG. 18 .
[0038] FIG. 20 is a detailed cross sectional view of the stud locking tab and its corresponding mating track channel locking tab in position prior to having the stud inserted on the track channel.
[0039] FIG. 21 is an isometric view of an alternative embodiment of the locking tabs.
[0040] FIG. 22 is an isometric view of still another alternative embodiment of the locking tabs that use a press fit pin to improve the stability of the attachment.
[0041] FIG. 23 illustrates a detailed view of the press pin.
[0042] FIG. 24 illustrates still another embodiment of FIG. 22 .
[0043] FIG. 25 illustrates a detailed alternative embodiment of a method of attachment.
[0044] FIG. 26 illustrates the attached stud using the alternative embodiment shown in FIG. 25 .
[0045] FIG. 27 illustrates the alternative embodiment for the stud used in the track.
[0046] FIG. 28 illustrates use of a punching locking tab for the stud in combination with an angled dimple at the track.
[0047] FIG. 29 illustrates an angled dimple at the track.
[0048] FIG. 30 illustrates the use of a round dimple at the track.
[0049] FIG. 31 illustrates a detailed view of the round dimple.
[0050] FIG. 32 illustrates how a stud with a longitudinal rib at the flange may be attached.
[0051] FIG. 33 illustrates a detailed view of the oblong dimple that is used to attach the ribbed stud to the track.
[0052] FIG. 34 illustrates a large oblong dimple on the track.
[0053] FIG. 35 illustrates a top view of an alternative stud.
[0054] FIG. 36 illustrates a bottom view of the alternative stud shown in FIG. 35 .
[0055] FIG. 37 is a side view of an alternative locking clip that is a punched ‘louvered’ type which is attached to the web member of the stud.
[0056] FIG. 38 is a punched louvered member that provides an attachment position for the stud member attachment.
[0057] FIG. 39 is a bottom view of the ‘louvered’ tab embossed member.
[0058] FIG. 40 is a top view of the ‘louvered’ tab embossed member showing the triangular shape.
DETAILED DESCRIPTION OF THE INVENTION
[0059] FIG. 1 illustrates metal framing member 10 with knock out opening 12 and tab 14 . While tab 14 is usually made so that tab 14 is approximately 90 degrees with surface 16 , since tab 14 is made at the factory using computer assisted machinery, any precise angle may be selected. (See, e.g. FIG. 13 ) Tab 14 and its corresponding knock out opening 12 are preferably located centrally in surface 16 , which runs the length of framing member 10 . However, since the stud is manufactured to the design specifications necessary to ensure precision and ease of fastening, other positions can be easily selected. In fact, different locations on surface 16 as well as different tab angles could be provided in each framing member if desired.
[0060] Surface section 16 is generally 6″ to 8″ wide. In the preferred embodiment, surface section 16 includes stiffeners 18 , which run longitudinally along surface section 16 . Typically, as noted above, knock out opening 12 is centrally located between stiffeners 18 . Note that the geometry and size of knock out opening 12 and tab 14 are substantially the same, differing primarily due to the width of the cut. By having opening 12 and tab 14 substantially the same, less material is wasted and the framing member is stronger thus exhibiting a greater resistance to torsion forces and axis buckling.
[0061] Knock out opening 12 is shown in detail in FIG. 2 . Opening 12 is cut out of surface portion 16 in an area preferably no greater than two inches by two inches. Because this opening and tab 14 are made during the time of manufacturing the framing member 10 , the gauge of framing member 10 can be far thicker than would be otherwise possible if the installer had to bend tab 14 at the construction site.
[0062] In the preferred embodiment, opening 12 is 1 11/16″ by 1 11/16″, with upper end 20 of the chase having a radius of ⅞″ instead of being cut square. Tab 14 is not completely severed from opening 12 , but is connected along lower edge 22 . Preferably, tab 14 is folded up at lower edge 22 so that tab 14 is substantially perpendicular to raised surface section 16 . However, as noted above, other angles are easily selectable depending on the needs of the construction project.
[0063] FIG. 3 details tab 14 . In addition to the primary purpose of tab 14 to provide an accurate positioning and fastening location for adjacent framing members, tab 14 can serve as a point of attachment for any objects passing through opening 12 such as wiring. Wiring or other objects may be passed from one side of the framing member to the other through opening 12 thus serving as a chase. These objects may then be fastened to tab 14 without adding additional clips.
[0064] In the preferred embodiment, two holes 24 are provided in tab 14 to serve as fastener holes. One hole 24 is positioned ½″ from lower edge 22 , while the other is positioned ½″ from rounded edge 26 . Holes 24 are otherwise centered on tab 14 . Holes 24 preferably have a radius of 3/32″ and are capable of receiving standard screw fasteners (not shown) to attach wiring, stiffening rods, or other framing members to tab 14 .
[0065] Returning to FIG. 1 , stud framing member 10 includes left and right rectangular sections 28 . Rectangular side sections 28 are preferably at least 1 ⅝″ in length, but may vary depending on the particular need for the framing member. Rectangular side sections 28 share an edge with surface section 16 and are substantially perpendicular to surface section 16 while being parallel to each other. At the distal ends of rectangular side sections 28 are left and right rectangular returns 30 . Left and right rectangular returns 30 are preferably perpendicular to rectangular side sections 28 and parallel to bottom section 16 .
[0066] FIG. 4 is a cross section of stud framing member 10 , including stiffeners 18 that run the length of the member. Stiffeners 18 are ideally located on surface section 16 about 1 ½″ to 2″ from rectangular side sections 28 , depending on the width of bottom section 16 . As can be seen from FIG. 4 , rectangular returns 30 do not generally extend out over stiffeners 18 . It can also be seen that corners 32 , formed where rectangular side 10 sections 28 meet bottom section 16 , and corners 34 , formed where rectangular returns 30 meet rectangular side sections 28 , may be radiused edges rather than sharp comers.
[0067] FIG. 5 is a cross section of an alternate embodiment of framing member 10 . In this embodiment, bottom section 16 does not include stiffeners 18 . Rather, surface section 16 is flat across its entire width other than opening 12 and tab 14 .
[0068] As shown in FIG. 6-8 , there is another alternative embodiment of the framing member 15 showing a plurality of manufactured layout locating tabs 14 . Note that the position of tabs 14 and the corresponding knock out openings 12 can be located anywhere along the framing member. That is, it is unnecessary to use only 16 inches on center as would be required if tabs 14 and openings 12 were not made specifically to meet the requirements of each and every construction project.
[0069] FIG. 9 is another embodiment of manufactured layout locating tabs 14 ′ shown in the framing member depicted in FIG. 6 . In this embodiment, tabs 14 ′ and their corresponding knock out openings 12 ′ are rectangular in shape. Clearly, other shapes are likewise possible such as triangular, octagonal, hexagonal, etc. depending on the job requirements. Since the tabs and openings are made during the construction process of the framing member, with the tab aligned at the predetermined angle relative to the web surface of framing member, a virtual infinite number of tab permutations and combinations are possible.
[0070] FIG. 12 shows a typical framed wall that uses the tabs 14 to attach one framing member to the next in precise alignment. Note that the distance between the respective framing members is not always a standard (16 inches O.C.) so that the tabs (not shown) on header framing member 42 are adjusted accordingly. Also, openings and tabs can be provided so that cross bracing members 44 and 46 are accurately position therethrough thus providing a tab for attachment as well as making certain the framed wall is square. This can be seen more clearly in FIG. 13 which shows that tab 14 is positioned at an angle other than 90 degrees with respect to surface portion 16 .
[0071] As shown in FIG. 14 , the framing member invention can even be used to construct trusses which require joining one framing member to another at varying angles and positions. The flexibility of this system is clearly illustrated in FIG. 15 which illustrates that tab 14 can be positioned at the top of framing member 10 such that one framing member 10 can be attached to another at substantially right angles.
[0072] FIG. 16 is an isometric view of locking tabs being used to connect a stud member 50 with a track channel member 58 in accordance with the invention. While the stud member 50 is shown as the applicant's patented STRONG STUD described above, a track channel, other metal structural members can also be used with the invention.
[0073] A tab attachment assembly having at least two raised portions 52 is provided in the web of stud member 50 . A punched locking tab 54 is provided in each of raised portion 52 . An angled material guide 56 is also provided in each of raised portion 52 . At least two punched knock-out tabs openings 62 are provided in the upper portion of slotted tab 60 in track or channel member 58 . Track or channel member locking assembly is aligned so that tab opening 62 is aligned with the tab attachment assembly of stud member 50 . Once stud member 50 is inserted over upper portion of slotted tab 60 , the two parts are attached together. The stability of the attachment is augmented by the use of knock-out locking surface 64 of stud member 50 which engages locking surface of locking tab 66 of track channel member 58 . This is shown only on one leg of the respective parts but could also be used as a match set on both legs.
[0074] Referring now to FIGS. 17-19 , detailed views of the preferred embodiment of the locking tab assembly that is provided on stud member 50 are shown. Note that guide member 56 is angled slightly to enable the locking tab assembly to be slid over the upper portion of slotted tab 60 of the track channel member 58 . Punched locking tab 54 engages punched knock-out tab opening 62 of tab 60 so that the two parts are held firmly together as shown in FIG. 20 .
[0075] FIG. 20 is a detailed cross sectional view of the stud locking tab and its corresponding mating track channel locking tab in position prior to having the stud member 50 attached to track channel member 58 . Note that once fully engaged, locking tab 66 is inserted into punched knock-out tab opening 62 thus holding the two parts firmly together.
[0076] FIG. 21 is an isometric view of an alternative embodiment of the locking tabs. In this embodiment, the knock-outs are a radius locking tab 74 and a corresponding circular opening 76 . As can be seen, the tab and its receiving knock-out opening can be any mating shaped pair such as a rectangle, square, circular, oval, etc. as long as the opening and its tab are dimensioned so that the tab fully engages the opening once one member engages the other.
[0077] The remaining drawings show the various permutations and combinations that can be used to attach stud member 50 to track channel member 58 .
[0078] FIG. 22 is an isometric view of still another alternative embodiment of the locking tabs that use a press fit pin 72 to improve the stability of the attachment. Matched openings 68 and 70 are provided wherein press pin 72 is pressed through the two fully engaged parts to more firmly hold the two together. Press pin 72 may be plastic or metal or another material that has sufficient structural strength to withstand the forces expected when the two parts are attached. Press pin 72 is preferably shaped so that once press pin 72 is inserted, removal is extremely difficult thus ensuring that the two parts are locked together as is accomplished with locking tab assembly.
[0079] FIG. 23 illustrates a detailed view of the press pin 72 .
[0080] FIG. 24 illustrates still another embodiment of FIG. 22 . In this embodiment, press pin 72 is eliminated. Instead, a square receiving hole 78 is provided on track channel member 58 . The stud is attached to the track by a square angled dimple 77 .
[0081] FIG. 25 illustrates a detailed alternative embodiment of a method of attachment. It shows a detailed view of the square angled dimple 77 .
[0082] FIG. 26 illustrates the attached stud member 50 using the alternative embodiment shown in FIG. 25 . In this embodiment, the stud member 50 is attached to track channel member 58 using a square receiving hole 79 as a dimple which engages a square angled dimple 80 on track 58 .
[0083] FIG. 27 illustrates a detailed view of the square angled dimple 80 that is positioned on the track channel member 58 .
[0084] In this view, FIG. 28 illustrates a squared dimple 82 on track channel member 58 and a square receiving hole 79 on the stud member 58 .
[0085] FIG. 29 is a detailed view of the squared dimple 82 on track channel member 58 .
[0086] FIG. 30 illustrates the use of a round receiving hole 83 on stud member 50 as a dimple. Correspondingly on track channel member 58 , round dimple 84 is used to attach to receiving hole 83 .
[0087] FIG. 31 is a detailed view of the round dimple 84 on track channel member 58 that is shown being used in FIG. 30 .
[0088] As shown in FIG. 32 , a stud member 50 that has a longitudinal rib 85 may also be attached to track channel member 58 using this method. In this embodiment, a large oblong dimple is provided on track channel member 58 . The stud member 50 is attached by moving the stud member 50 as shown by the arrows so that the rib 85 lines up with dimple 86 .
[0089] FIG. 33 is a side view of the dimple that is found on track channel member 58 .
[0090] FIG. 34 is a top view of the oblong dimple 86 on track channel member 58 .
[0091] FIG. 35 illustrates a top view of an alternative stud member 50 .
[0092] FIG. 36 illustrates a bottom view of the alternative stud member 50 shown in FIG. 35 .
[0093] FIG. 37 is a side view of an alternative locking clip that is a punched ‘louvered’ type which is attached to the web member of the stud.
[0094] FIG. 38 is a punched louvered member that provides an attachment position for the stud member attachment. The use of the punched ‘louvered’ type of catch is positioned within the flat portion of the tab/clip. Thus, it provides a greater holding power.
[0095] FIG. 39 is a bottom view of the ‘louvered’ tab embossed member.
[0096] FIG. 40 is a top view of the ‘louvered’ tab embossed member showing the triangular shape. When attached to the clip shown in FIG. 37 , a more secure lock is provided than can be achieved by merely the use of the punched version of the tab and dimpled locking mechanism.
[0097] Although the present invention has been described with reference to certain preferred embodiments thereof, other versions are readily apparent to those of ordinary skill in the art. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiments contained herein.
|
A metal framing member for use as a stud, joist, rafter, truss, etc. is disclosed. The framing member includes at least one knock out opening and a corresponding tab that is positioned onto the metal framing member during the manufacturing process via computer so that structures built using the studs such as window frames, door jams, etc. are accurately and quickly fabricated. The knock out opening can also be used as a chase to allow wiring or a stiffening rod to pass through the member. Each tab is also preferably provided with a pair of pre-punched holes so that the tab can be fastened to other building components using standard screws.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority to U.S. patent application Ser. No. 13/583,527, filed Sep. 7, 2012, now allowed, which is a U.S. National Phase Application of International Application No. PCT/IL2011/000223, filed Mar. 9, 2011, which claims the benefit of priority to Israeli Application No. 204389, filed Mar. 9, 2010, each of which is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to heat engines and more particularly to Liquid Ring Rotating Casing Compressor (LRRCC) heat engines.
BACKGROUND OF THE INVENTION
[0003] In a liquid ring expander, an impeller with blades mounted on it is mounted eccentrically in an expander body. A service liquid is present in the expander body and is flung against the wall of the expander body as a result of the centrifugal forces generated by rotation of the impeller. The volume of the service liquid is less than the volume of the expander body. In this way, the service liquid in the expander body forms a circumferential liquid ring which forms chambers bounded in each case by two blades and the liquid ring. Owing to the eccentric positioning of the impeller in the expander body, the size of the chambers increases in the direction of rotation of the impeller, thus allowing gas introduced at high pressure into the narrow chambers of the expander to expand and thereby rotate the impeller.
[0004] A liquid ring compressor operates in an analogous manner, only in this case gas is introduced into the widest chamber of the expander such that the size of the chambers decreases in the direction of rotation of the impeller. Owing to the rotation of the impeller and the reduction in the size of the chambers, the gas which has been drawn in is compressed and ejected from the liquid ring expander on the high pressure side.
[0005] US 2008/0314041 (corresponding to IL 163263) in the name of the present inventor discloses a heat engine that includes at least one Liquid Ring Rotating Casing Compressor (LRRCC) having a fluid inlet and a fluid outlet, a combustion chamber in fluid communication with the output of the LRRCC, and at least one expander having a fluid inlet and a fluid outlet. The fluid inlet communicates with the combustion chamber. Efficient LRRCC compressors/turbines are also known from EP 804 687.
[0006] The contents of both US 2008/0314041 and EP 804 687 are incorporated herein by reference.
[0007] In the heat engine described in US 2008/0314041, an LRRCC is used in tandem with an expander, which may be a conventional turbine or a liquid ring expander of the kind described above. In the case where the turbine is a liquid ring expander having arotating casing, air at high pressure and high temperature is injected into the casing so as to rotate the impeller.
[0008] Liquid ring turbines are only feasible if the casing rotates together with the impeller since the friction between the impeller and a fixed casing is prohibitive to obtaining reasonable efficiency. Rotating casing rotating liquid ring turbines are known in the literature but have so far been only theoretical based on the physical principle that an expander is complementary to a compressor. While this is, of course, true in principle, practical rotating casing liquid ring turbines do not appear to have been realized and most turbines currently in use employ very high pressure steam to rotate the turbine at high speeds. As is well-known, several turbines are often employed in cascade, the steam emitted from one turbine being use to rotate the next turbine and so on, until the pressure of the steam is too low to be of effective use. The steam is then cooled using cold water which may come from a river, the sea or a cooling tower.
[0009] The use of steam in a rotating casing rotating liquid ring turbine has been proposed by U.S. Pat. No. 4,112,688 (Shaw), which describes a rotating liquid ring turbine driven by an expanding gas and having a rotating casing. Shaw requires that no change of phase occurs in the energy transfer medium as, for example, occurs in the case of the Rankine turbine cycle in which water is converted to steam and back again with unavoidable energy losses, and reduced operating efficiency.
[0010] However, in order to meet this requirement, energy must be constantly supplied during the expansion phase to maintain the working medium as steam and thus prevent it from condensing. This is achieved by the provision of heat exchangers in the impeller.
[0011] As described, for example, in Wikipedia®, use of the Rankine cycle is well established in steam turbines where a pump is used to pressurize working fluid received from a condenser as a liquid instead of as a gas. All of the energy in pumping the working fluid through the complete cycle is lost, as is all of the energy of vaporization of the working fluid, in the boiler. This energy is lost to the cycle in that first, no condensation takes place in the turbine; all of the vaporization energy being rejected from the cycle through the condenser. But pumping the working fluid through the cycle as a liquid requires a very small fraction of the energy needed to transport it as compared to compressing the working fluid as a gas in a compressor (as in the Carnot cycle).
[0012] The working fluid in a Rankine cycle follows a closed loop and is reused constantly. The water vapor with entrained droplets often seen billowing from power stations is generated by the cooling systems (not from the closed-loop Rankine power cycle) and represents the waste energy heat (pumping and vaporization) that could not be converted to useful work in the turbine.
[0013] One of the principal advantages the Rankine cycle holds over others is that during the compression stage relatively little work is required to drive the pump, the working fluid being in its liquid phase at this point. By condensing the fluid, the work required by the pump consumes only 1% to 3% of the turbine power and contributes to a much higher efficiency for a real cycle. The benefit of this is lost somewhat due to the lower heat addition temperature as compared with gas turbines, for instance, which have turbine entry temperatures approaching 1500° C. FIG. 1 is a Temperature (T)-Entropy (S) diagram for the conventional Rankine cycle (based on open source data in Wikipedia®), showing that there are four processes identified as follows:
[0014] Process 1-2: The working fluid is pumped from low to high pressure; as the fluid is a liquid at this stage the pump requires little input energy.
[0015] Process 2-3: The high pressure liquid enters a boiler where it is heated at constant pressure by an external heat source to become a dry saturated vapor.
[0016] Process 3-4: The dry saturated vapor expands through a turbine, generating power. This decreases the temperature and pressure of the vapor, and some condensation may occur.
[0017] Process 4-1: The wet vapor then enters a condenser external to the turbine where it is condensed at a constant pressure to become a saturated liquid.
[0018] In an ideal Rankine cycle the pump and turbine would be isentropic, i.e., the pump and turbine would generate no entropy and hence maximize the net work output. Processes 1-2 and 3-4 would be represented by vertical lines on the T-S diagram and more closely resemble that of the Carnot cycle. The Rankine cycle shown in FIG. 1 prevents the vapor ending up in the superheat region after the expansion in the turbine, which reduces the energy removed by the condensers.
[0019] Point 3 lies on the envelope of the T-S curve that delineates between vapor and gas. Thus, if the working fluid is water, to the right of point 3, the working fluid is pure steam while to the left, i.e. within the envelope of the T-S curve it is wet steam and to the left of point 1, it is water. In practice, it is considered undesirable in a practical turbine to reduce the temperature of the working fluid from 3 to 4 since the steam is wet and when water droplets impinge at high pressure on the turbine blades they are liable to cause damage such as pitting and erosion of the blades. This derogates from the performance of the turbine and in time causes irreversible damage, rendering the blades unusable. This problem has been solved using special materials that are resistant to erosion, but these are very expensive.
[0020] To avoid pitting caused by wet steam while using conventional materials, it is common to employ superheating of the steam at point 3, so as to raise the temperature to close to 1,000° C. before being directed on to the turbine blades. Superheating, shown by the chain-dotted line, dries the steam thus avoiding the problem of pitting of the turbine blades. Typically, the steam is allowed to condense to a point denoted by 5 on the T-S curve, where its temperature is much reduced and is then re-heated and directed again on to the turbine blades as dry steam where it loses heat and strikes the T-S curve at point 6 where its entropy (S) is significantly higher than that for the conventional Rankine cycle without superheating.
[0021] In summary, the Rankine cycle requires either that special materials are used for the turbine blades in which case isentropic heat-energy conversion is possible but at the cost of highly expensive turbine blades; or superheating is required so as to ensure that during the heat-energy conversion stage the steam is maintained dry. This reduces the overall efficiency of the engine.
[0022] The present invention seeks to offer the benefits of a near-Rankine cycle which is essentially isentropic without requiring the steam to be dry during the heat-energy conversion stage.
SUMMARY OF THE INVENTION
[0023] One object of the invention is to employ steam in a rotating casing rotating 30 liquid ring turbine while avoiding condensation of the steam at least until it has done sufficient work, thereby rendering it effective as a propellant.
[0024] It is another object to provide a gas turbine that uses a partial Rankine cycle, which is essentially isentropic but does not require the steam to be dry during the heat-energy conversion stage.
[0025] According to one aspect of the invention there is provided a rotating liquid ring rotating casing gas turbine, comprising:
[0026] at least one liquid ring rotating casing having an eccentrically mounted impeller adapted to rotate within a surrounding liquid ring so as to form chambers of successively increasing volume between adjacent vanes of the impeller,
[0027] a fluid inlet within a static axial bore of the impeller for injecting a fluid as a gas at high pressure into the impeller where the chambers are narrow so as to rotate the impeller and in so doing to expand essentially isentropically, and
[0028] a fluid outlet within the static axial bore of the impeller and fluidly separated from the fluid inlet for allowing the fluid to escape at low pressure and low temperature.
[0029] According to another aspect of the invention there is provided a heat engine that includes such a turbine.
[0030] A major benefit of such an approach is that no compressor is required, thus saving energy and increasing the thermodynamic efficiency. This in turn means that a heat engine employing the rotating liquid ring rotating casing gas turbine is smaller and suitable for relatively low-power applications operating at low temperature and speed. For example, as distinct from conventional turbines that operate in excess of 130° C. and have an efficiency of approximately 12%, the turbine according to the invention can operate at as low as 100° C. and yet has an efficiency of 16%.
[0031] Yet a further benefit is that the turbine according to the invention may employ an open water cycle where cold water after condensation does not need to be re-heated to form steam as is commonly done in steam turbines. Thus, while the invention could also employ a closed cycle if desired, better thermodynamic performance is achieved by using a constant source of geothermically heated water, where the wet steam leaving the turbine is condensed and returned to the atmosphere.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
[0033] FIG. 1 is a Temperature-Entropy diagram for the conventional Rankine cycle useful for explaining where the invention departs from conventional steam turbines;
[0034] FIG. 2 shows schematically a cross-section of a LRRC steam turbine having an external steam condenser according to a first embodiment of the invention;
[0035] FIG. 3 shows schematically a cross-section of a LRRC steam turbine having an internal steam condenser according to a first embodiment of the invention;
[0036] FIG. 4 is a block diagram of a heat engine employing the LRRC steam turbine of FIG. 1 ;
[0037] FIG. 5 is a block diagram of a heat engine employing the LRRC steam turbine of FIG. 3 ; and
[0038] FIG. 6 is a pictorial perspective view of a heat engine according to the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0039] In the following description of some embodiments, identical components that appear in more than one figure or that share similar functionality will be referenced by identical reference symbols.
[0040] Referring to FIG. 2 , there is shown in schematic cross-section a rotating liquid ring turbine wherein an impeller 11 with radial blades 12 rotates counter-clockwise around static ducts. The impeller is enclosed by a rotating casing 13 that contains a liquid ring 14 and rotates about an axis that is parallel but eccentric to the axis of the impeller so as to form chambers 15 bounded in each case by two blades 16 and the liquid ring. A mechanical coupling such as partially meshing annular gear trains 17 and 18 may be provided between the impeller and the casing so as to rotate the impeller and the casing at a similar rate. Owing to the eccentric positioning of the impeller in the rotating casing, the chambers increase in size in the direction of rotation of the impeller.
[0041] A fluid inlet 19 is provided near where the impeller blades are closest to the internal wall of the casing where the chambers are narrow so as to be wholly immersed in the rotating liquid ring, while at the opposite end (shown toward the bottom of FIG. 2 ), where the impeller blades are farthest from the internal wall of the casing, there is provided a fluid outlet 20 . In use, steam at high pressure is injected into the fluid inlet 19 , which is connected to multiple inlet ports in the narrow chambers so as to strike the impeller blades thereby rotating the impeller, and is emitted at low pressure from the fluid outlet 20 . In doing so, the steam makes contact with the liquid in the liquid ring, some of which may be ejected from the fluid outlet 20 with the condensed steam. More significantly, oil is allowed to exit via a liquid outlet 21 , which is located near the impeller so as to ensure that the impeller blades are completely filled with liquid where the impeller is closest to the internal wall of the casing. The liquid outlet 21 ensures that the depth of the liquid ring does not increase thereby occupying space in the chambers 15 that must be empty so as to allow for the entry of steam. In order to ensure that the volume of liquid in the liquid ring is properly regulated, there is likewise provided a liquid inlet 22 for pumping liquid into the turbine casing 13 . The liquid inlet 22 and the liquid outlet 21 allow the oil level and temperature to be controlled dynamically. The fluid inlet 19 and the fluid outlet 20 are both formed in a static axial bore 23 of the impeller 11 and are fluidly separated from each other.
[0042] At the compression zone on the right side of FIG. 2 , the rotating liquid radial flow is directed towards the static axial bore 23 of the impeller where the liquid functions as a piston compressor. At the left side of FIG. 2 the radial liquid flow is from the center to the rotating casing and constitutes an expanding zone.
[0043] In a LRRC compressor such as described in US 2009/0290993, gas enters the impeller from the central duct at the lower end in proximity to the compression zone.
[0044] In contrast thereto, in the LRRC turbine 10 shown in FIG. 2 , gas enters the narrow chambers of the impeller via the fluid inlet 19 and thereafter expands inside the impeller towards the turbine blades, where the chambers are large. In the process, the gas expands and undergoes a gas-to-liquid phase change and can therefore operate as the working fluid of a Rankine cycle heat engine, thus avoiding the need for a compressor as is necessary in above-mentioned US 2009/0290993. This requires that the working fluid be such as to change phase, preferably after completing its useful work, whereupon it is condensed and discharged. A suitable working fluid is steam.
[0045] FIGS. 2 and 4 depict a LRRC steam turbine 30 according to a first embodiment wherein steam is generated by a steam source 31 such as a flash evaporator and fed via the steam inlet shown as 19 in FIG. 2 to a turbine 10 of the kind described above having a rotating liquid ring formed of oil. It expands inside the impeller on its way downwards 30 towards the expanding section of the turbine. The expanded steam enters the central duct 20 , which thus constitutes a fluid outlet (depicted by arrows on the right of the central ducts in FIG. 2 ). Oil stored in a reservoir 32 is pumped by a pump 33 to an oil heater 34 and the heated oil is injected into the liquid ring fluid inlet shown as 22 in FIG. 2 . Any oil that exits from the liquid outlet 21 of the turbine is allowed to replenish the oil in the reservoir 32 . Steam exiting from the fluid outlet 20 of the turbine enters an external steam condenser 35 wherein steam is introduced at high pressure into a fluid inlet thereof. A source of cold water, such as cooling tower 36 , sprays cold water by means of a pump 37 into the condenser 35 thereby condensing the steam exiting from the fluid outlet 20 of the turbine. The water in the condenser becomes heated owing to the condensation of steam and is pumped back to the cooling tower 36 by a pump 38 where the heat is dissipated to the atmosphere. The condenser 35 must operate under very low pressure in order to ensure efficient condensation. In order to preserve low air pressure, any gases that enter the condenser 35 and cannot be condensed are removed by a vacuum pump 39 .
[0046] In a preferred embodiment, the liquid ring is formed of a type of oil that is denser than water and immiscible therewith, and may be maintained at a higher temperature than the steam in order to avoid steam condensation on the liquid ring. Since the working fluid is completely immiscible with the oil in the liquid ring, only working fluid (e.g. condensed steam) exits from the fluid outlet 20 into the central static duct 21 in FIG. 1 .
[0047] FIGS. 3 and 5 show another embodiment of a heat engine 40 where common features are designated by the same reference numerals as shown in FIG. 4 and operate in like manner. Cold water from a cooling tower 36 is pumped by a pump 41 and sprayed inside the turbine 10 via spray nozzles 42 (shown in FIG. 3 ), and is used as a steam condenser, thus obviating the need for an external condenser as shown in FIG. 4 . The hot water is collected at the oil reservoir 32 as a mixture of water and dense oil and flows to a liquid separator 43 shown in FIG. 5 from where the oil is pumped by a pump 44 back to the turbine and hot water is pumped by a pump 45 back to the cooling tower 36 where it is cooled and returns as cold water to the cold water spray nozzles 42 in FIG. 3 . Steam generated by a steam source 31 such as a flash evaporator is fed via the steam inlet shown as 19 in FIG. 3 to a turbine 10 .
[0048] In this embodiment, there are three inputs to the turbine since an additional inlet is required for the cold water spray and, as noted, there is thus no need for an external condenser. There is likewise no need for an oil heater, which will in any case be heated by the steam. To the extent that the liquid in the liquid ring is cooler than the incoming working fluid, the working fluid may condense on the liquid ring. This is obviously not desirable since the working fluid in its gaseous state is what drives the impeller. On the other hand, it will be understood that as a result of condensation of the working fluid, the liquid in the liquid ring becomes heated and an equilibrium state is created that impedes further condensation. For this reason, it is believed that water may also be used as the liquid ring.
[0049] While in the embodiment described above, a heated oil ring is proposed in order to avoid condensation of the steam, this may give rise to undesirable mixing forming an oil-water emulsion which may be undesirable.
[0050] Furthermore, reverting to FIG. 2 , steam enters the fluid inlet 19 at the upward left side of the turbine and heats the water ring in contact therewith. The heated liquid ring cools during the few milliseconds that it takes to rotate through 2-3 radians (approx. 180°) when it approaches the lower end section of the turbine. Consequently, some of the steam is absorbed by the liquid ring and does not generate shaft work.
[0051] For these reasons it is more effective to use a desiccant liquid ring such as brine, which avoids both of these drawbacks. As before, steam enters the fluid inlet 19 and, upon encountering the liquid desiccant ring in the expanding zone, the steam condenses on the liquid interface. The diffusion of water inside the liquid brine is extremely small (approximately 10 −9 m 2 /s) and the water depth at the brine steam interface will be only several microns. Within a short time interval of only several milliseconds the liquid ring interface will face low pressure steam (at the lower end of FIG. 3 ) and the water at the brine liquid interface will evaporate to the exit steam. Consequently, only a small fraction of the steam will travel with the liquid ring and the bulk of the steam will expand and induce effective work.
[0052] The invention also contemplates a method for generating shaft work using the turbine as described.
|
A rotating liquid ring rotating casing gas turbine ( 10 ) has at least one liquid ring rotating casing ( 13 ) having an eccentrically mounted impeller ( 11 ) adapted to rotate within a surrounding liquid ring ( 14 ) so as to form chambers ( 15 ) of successively increasing volume between adjacent vanes of the impeller. A working fluid formed by high pressure gas is injected into the impeller where the chambers are narrow via a fluid inlet ( 19 ) within a static axial bore ( 23 ) of the impeller so as to rotate the impeller and in so doing the gas expands isentropically. A fluid outlet ( 20 ) within the static axial bore of the impeller and fluidly separated from the fluid inlet allows the working fluid to escape at low pressure and low temperature.
| 5
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is directed to a rotatable looptaker and bobbin case assembly for use in a lockstitch sewing machine.
2. Description of the Prior Art
A bobbin case can only be loosely confined within the looptaker of a lockstitch sewing machine because a loop of thread must be moved about the bobbin case to form a stitch. Such loose confinement has permitted movement of the bobbin case within the looptaker and a resulting high level of bobbin case noise during the operation of the machine.
It is a prime object of the present invention to minimize bobbin case noise in a lockstitch sewing machine.
It is another object of the invention to resiliently restrict the movement of a bobbin case in a sewing machine by forces resulting from frictional engagement of the looptaker with bobbin case and the engagement with the bobbin case of an encircling thread loop during operation of the machine.
It is also an object of the invention to control the movement of a bobbin case in a lockstitch sewing machine with a light force applying member and a cushioning shock absorber in a manner enabling a thread loop to be moved about the bobbin case as required for proper stitch formation.
Other objects and advantages of the invention will become apparent during a reading of the specification taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
A lockstitch sewing machine, including a rotatable vertical axis looptaker with a beak for seizing needle thread during looptaker rotation in a defined direction, and including a bobbin case that is loosely confined by the looptaker, is provided with a light force applying resilient member in continuous biasing engagement with the bobbin case for urging one side of the bobbin case against the looptaker, and said bobbin case rotationally with respect to the looptaker axis in a direction opposite to said defined direction of rotation of the looptaker toward a position of engagement with a stop which is fixedly located on the machine bed. A resilient shock absorber located a predetermined distance from the bobbin case in a position adjacent the bobbin case is engageable thereby only upon movement of the bobbin case in opposition to the bias of said resilient member.
DESCRIPTION OF THE DRAWINGS
FIG 1 is a fragmentary top plan view showing a looptaker and bobbin case assembly according to the invention before rotation of the looptaker;
FIG. 2 is a vertical sectional view taken on the plane of the line 2--2 of FIG. 1;
FIG. 3 is a view similar to FIG. 1 illustrating the effect of looptaker rotation on the bobbin case;
FIGS. 4 through 8 are top plan views of the looptaker and bobbin case showing a needle thread loop in different positions as it is moved about the bobbin case.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1, 2 and 3 of the drawings, reference character 10 designates a sewing machine bed with an upwardly open compartment 12 for a looptaker 14. Compartment 12 is formed with a lower and upper shelf 15 and 16, respectively. The upper shelf accommodates a slide plate cover 18 and a throat plate (not shown). Compartment 12 also accommodates a feed dog 20 of a conventional drop mechanism which may be opposed by a conventional presser foot 22 mounted in a bracket arm (not shown) of the sewing machine along with a needle 24 to which endwise reciprocating motion may be imparted in the usual manner.
Looptaker 14 includes a shaft 26 which is journalled for rotation about vertical axis 28 in a bushing 30 secured by a set screw 32 in a boss 34 depending from the bottom wall 36 of compartment 12. As shown, the looptaker includes a cup shaped body portion 38 with a flat bottom 40 and a cylindrical side wall 42 encompassing an upwardly open cavity 44. Side wall 42 is formed with an inwardly extending bearing rim 46 and an upwardly extending bearing shoulder 48. A vertical slot 50 in side wall 42 defines an inwardly directed needle loop seizing beak 52 in body portion 38. Counterclockwise rotation of the looptaker 14 (as viewed in the top views of the drawings), and endwise reciprocation of the needle 24 in timed relation relative to the looptaker is provided for with conventional mechanism (not shown) which is preferably adapted to impart two revolutions to the looptaker for each reciprocation of the needle.
A bobbin case 54 is received in looptaker cavity 44. The bobbin case includes a central portion 56 with a cylindrical bobbin accommodating cavity 58 wherein a conventional bobbin 60 is supported for rotation. The bobbin case also includes a flange 62 extending radially outward from central portion 56. As shown, the flange is mostly curved, but includes slabbed edge portions 64 and 65 on one side of the bobbin case. The flange has a planar underside 66 and includes a curvilinear notch 67.
A bracket 68 and overlying plate 69 are adjustably secured by screws 70, 72, 73 and 74 to shelf 15 in looptaker compartment 12. The bracket includes a short arm 76 with a top projecting tab 78 which extends just forwardly of the line of reciprocation of needle 24 into bobbin case notch 67 where it is loosely received. The bracket further includes second arm 80 which is parallel to arm 76 and overlies the forward edge of the bobbin case. The bracket is formed with straight edge portions 82 and 84 which lie adjacent the slabbed edge portions of the bobbin case, and provide an exit passageway 86 between the bobbin case and bracket for needle thread moved about the bobbin case during the operation of the machine. Plate 69 is formed with a tongue 87 which overlies the bobbin case flange 62 as shown.
The bobbin case 54 is vertically supported by arm 76 on opposite sides of tab 78, and by engagement of rim 46 of the looptaker with a portion of the underside 66 of the bobbin case flange 62. Bracket arm 80, the tongue 87 of plate 69, and a dog 88 removable secured to shelf 15 with a screw 90 so as to extend over flange 62, loosely confine the bobbin case axially. A resilient member 92 extends into passageway 86 to engage the bobbin case 54 and bias the bobbin case generally leftward as viewed in the drawings. A resilient shock absorber 94, which extends into the forward end portion of the passageway, and tab 78 on bracket 68 loosely confine the bracket case rotationally.
Resilient member 92 is a looped wire spring located between plate 69 and bracket 68, and extending through a recess 96 in the underside of plate 69 where opposite ends 98 and 100 of the spring are wrapped about posts 102 and 104 respectively. The spring extends across passageway 86, as shown, to engage the bobbin case bracket. Shock absorber 94 is wire spring with a ninety degree bend 106. One end portion 108 of spring 94 is wrapped about a pin 110 in bracket 68 and engaged by a bracket affixed stop 112 as shown, whereas the opposite end portion 114 extends into passageway 86.
Spring 92 continuously exerts a light biasing force on bobbin case 54 insufficient to interfere with the movement of thread about the left side of the bobbin case, through passageway 86 and past the spring 92. The spring acts generally to the left as already noted, and so urges the left side of the bobbin case to engagement with looptaker shoulder 48. The disposition of spring 92 is such that the directional line 116 of the force exerted by spring 92 on the bobbin case passes forwardly of the axis 28 of looptaker 14 wherein the bobbin case is supported on rim 46. Spring 92, therefor, also acts to rotate the bobbin case in a clockwise direction about the looptaker axis to a limited position of engagement in notch 67 with tab 78 acting as stop.
Shock absorber spring 94 is so located as to have end portion 114 separated from bobbin case edge portion 65 by a predetermined gap 116 while the looptaker 14 is stationary. Space 118 is provided behind the spring to permit flexure in the direction of bracket 68. Counterclockwise rotation of the looptaker, initiated by operation of the machine, causes the frictionally engaged bobbin case 54 to be pivoted in a counterclockwise direction about the looptaker axis. The bobbin case initially impacts against spring end portion 114 and thereafter bears against the spring while the looptaker is rotated. The bobbin case can only be caused to engage spring end portion 114 by being moved through gap 116 against the bias of spring 92 to increase the compression thereof. Spring 92 therefor exerts a measure of control over the force exerted on spring 94 during the operation of the machine, and by lessening the forces on spring 94 facilitates the movement of thread past spring end portion 114 in passageway 86.
The manner in which sewing threads are manipulated in the assembly of the invention to provide for the formation of lockstitches may be readily seen in FIGS. 4 through 8 wherein N and B designate needle thread and bobbin thread, respectively. The bobbin thread B during sewing extends from a thread guiding notch 120 in the bobbin case 54, across the top of the bobbin and bobbin case, and thence to stitches being formed in the work.
In FIG. 4, the looptaker 14 is shown at the moment the looptaker beak 52 seizes a loop of thread from needle 24. FIG. 5 illustrates the position of the looptaker shortly after needle loop seizure and as the seized needle thread loop is beginning to be spread about bobbin case flange 62 with one limb of the loop over the bobbin case and the other limb extending thereunder. In FIG. 6, the looptaker has progressed beyond the position shown in FIG. 5 to a point where beak 52 has just past notch 120 to dispose the upper and lower limbs of the needle thread loop as shown. In FIG. 7, the looptaker has moved beyond the position at which the needle thread loop is pulled from beak 52. The thread is pulled the rest of the way about the bobbin case by the usual takeup, and is shown in FIG. 7 as it is being pulled past spring 94 into passageway 86. In FIG. 8, the needle thread loop is pulled by the looptaker across the right rear end portion of bobbin case flange 62 for use in the formation of a stitch with bobbin thread B.
During the movement of the needle thread about the bobbin case as described, forces are exerted by the thread on the bobbin case tending to move the bobbin case laterally and axially. Such forces vary in magnitude and direction depending upon the position of the needle thread loop and tend to cause the bobbin case to chatter. However, springs 92 and 94, while permitting thread to pass about the bobbin case, both restrict movement of the bobbin case and resiliently control the limited movement permitted, thereby preventing noise and chatter of the bobbin case as otherwise experienced, especially at low speed.
It is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only and is not to be construed as limiting the invention. Numerous alterations and modifications of the structure herein will suggest themselves to those skilled in the art, and all such modifications and alterations which do not depart from the spirit and scope of the invention are intended to be included within the scope of the appended claims.
|
A bobbin case, which is loosely confined within the looptaker of a sewing machine, is biased both into engagement on one side against the looptaker and about the looptaker axis toward a position of engagement with a stop by a continuously engaging light force applying resilient member, and a shock absorber is disposed for engagement with the bobbin case only upon movement thereof through a predetermined distance in opposition to the bias of said resilient member.
| 3
|
BACKGROUND OF INVENTION
The invention relates to the lighting arts. It is especially applicable to providing substantially uniform rectangular flood lighting of vertical walls or other flat vertical structures, and will be described with particular reference thereto. However, the invention is not limited thereto, and will also find application in other flood lighting tasks, such as the illumination of non-flat vertical objects, perimeter illumination of outdoor surfaces such as parking lots, football fields, and the like, and uniform illumination of indoor flooring using wall-mounted flood lights.
Flood lighting is typically used in parking lots, athletic fields, and other areas to provide illumination for convenience and safety. Similarly, architectural features such as building walls are advantageously uniformly illuminated at night. Flood lighting is designed to illuminate large areas, preferably with relatively uniform illumination across the area. To appropriately distribute the light output, the electric lamps that produce the light are typically coupled with a reflector. The reflector geometry for transforming the essentially point light source distribution of a conventional incandescent lamp, halogen lamp, or metal halide lamp into a wide-area, spatially uniform flood light illumination is typically rather complex. This is particularly the case for asymmetric flood lighting in which the flood light is not located symmetrically directly above the surface to be illuminated, but rather is located at a side, such cases arising for example in lighting parking lots from the perimeter, lighting athletic fields from the sidelines, lighting tall buildings from flood lights positioned relatively near ground level, and the like. Additionally, in such situations a substantially rectangular illumination of a substantially flat surface is typically desired, which further complicates the geometric requirements of the flood light reflector.
In the past, these complex geometric requirements have been met using multi-faceted segmented reflectors. These reflectors are assembled from multiple strips of pre-finished reflective metal, sometimes having various finishes. Segmented reflectors are relatively simple to manufacture since the required shaping can be accomplished using conventional and low cost sheet metal shaping techniques. However, these prior art reflectors have several disadvantages. They require labor-intensive assembly of the multiple parts, either at the factory or in the field, e.g. by the customer. The multiple-component fabrication introduces potential failure mechanisms at the interconnections. The multiple segments can have various types of surface finishes and segment interconnections of varying optical quality, producing lighting non-uniformities and other optical degradation.
Single-piece reflectors, which are typically machine-pressed from a single sheet of aluminum or other metal blank, are also known. U.S. Pat. No. 5,816,694, which has the same assignee as the present invention and is incorporated by reference herein, discloses a hydroformed symmetrical flood light reflector that produces a square light distribution. However, because of their more complex reflection geometry, asymmetrical flood light reflectors have in the past been produced in multi-segmented fashion rather than as single-piece reflectors.
The present invention contemplates an improved reflector that overcomes the above-mentioned limitations and others.
SUMMARY OF INVENTION
In accordance with one embodiment of the present invention, an asymmetric flood light reflector is disclosed. A hydroformed. continuous metal form defines a lamp space that is adapted to receive an associated lamp. The metal form has a forward opening for outputting light generated by the associated lamp. The metal form further includes a rear reflector section arranged rearward of the lamp space and adapted to reflect backward-directed lamp illumination forward in a crossing pattern, a forward reflector section disposed forward of the rear reflector section and adapted to reflect lamp illumination forward in a crossing pattern, and a plurality of planar surfaces that connect the forward and rear reflector sections. The hydroformed continuous metal form is adapted to cooperate with the associated lamp to produce a substantially rectangular area of substantially uniform illumination that is asymmetrically disposed relative to the reflector.
In accordance with another embodiment of the present invention, a flood light is disclosed, including a light source and an asymmetric reflector. The asymmetric reflector comprises a single, continuous, reflective metal sheet that is formed to include a plurality of reflective sub-surfaces. The reflector cooperates with the light source to produce uniform lighting over a rectangular area located asymmetrically relative to the flood light.
In accordance with yet another embodiment of the present invention, a method is disclosed for flood lighting a rectangular area in a substantially uniform manner. Light is generated at a spatial point asymmetrically located relative to the rectangular area. The generated light is reflected onto the rectangular area using a single metal sheet that has a pre-selected deformation shape adapted to reflect the generated light into the rectangular area with varying light intensity to provide substantially uniform illumination throughout the rectangular area.
In accordance with still yet another embodiment of the present invention, an apparatus for manufacturing an asymmetric flood light reflector is disclosed. The apparatus includes a punch element that is adapted for use with a hydroform press. The punch element conforms with the inner surface of an asymmetric flood light reflector.
Numerous advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description.
BRIEF DESCRIPTION OF DRAWINGS
The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention.
FIG. 1 shows an exemplary flood light that suitably practices an embodiment of the invention.
FIG. 2 shows an isometric view of an exemplary flood light reflector that suitably practices an embodiment of the invention.
FIG. 3 shows a top view of the reflector of FIG. 2 .
FIG. 4 shows a front view of the reflector of FIG. 2 .
FIG. 5 shows a side view of the reflector of FIG. 2 .
FIG. 6 shows an isometric view offset from the rear of the reflector of FIG. 2 .
FIG. 7 shows an isometric view of a hydroform punch for use in manufacturing, the reflector of FIG. 2 .
DETAILED DESCRIPTION
With reference to FIG. 1, an asymmetric flood light 10 includes a housing 11 containing an asymmetric reflector 12 and a lamp, light bulb, or other light source (not shown). The housing 11 protects the reflector, lamp, and associated electronic components (not shown). The reflector 12 includes a single formed piece of sheet metal. The flood light 10 is shown in FIG. 1 lighting a portion of a wall 14 . The flood light 10 is fixedly positioned at a pre-determined distance MD from the wall 14 , and at a pre-determined height MH above the ground 16 using any suitable mounting apparatus, such as a mounting pole 18 . The flood light 10 illuminates a substantially rectangular area 20 of the wall 14 . The flood light 10 is mounted at a selected tilt angle AT.
The lighting area 20 at the wall has a horizontal dimension X and a vertical dimension Y as shown, a center 22 , and is lit with substantially uniform intensity over the area of the lighting pattern 20 . Those skilled in the art will recognize that the dimensions X and Y of the lighting area 20 are advantageously quantified in units of the flood light 10 mounting distance MD from the illuminated wall 14 , in the illustrated case of FIG. 1, or equivalently in units of mounting height for a flood light illuminating a horizontal surface such as a parking lot or other horizontal area (arrangement not shown).
The reflector 12 is an asymmetric distribution reflector that produces a substantially rectangular light beam 24 directed upward (in the illustrated case of a vertically oriented asymmetric distribution reflector) so that the center 22 of the lighting area 20 is higher off the ground than the mounting height MH the flood lamp 10 . The upward thrust of the beam 24 is advantageously characterized by an azimuth angle AA. As seen in FIG. 1, the flood light 10 and the illuminated rectangular area 20 are asymmetrically relatively disposed, and a distal portion 26 of the rectangular area 20 is defined as a consequence of the asymmetric (non-zero) azimuth angle AA.
In FIG. 1, the flood light 10 is shown illuminating a vertical surface or wall, which could for example be the side of a house, multi-story building, or the like, an auditorium wall, atrium wall, or other substantially flat vertical structure. Although not shown herein, the flood light 10 could also be used to illuminate non-flat vertical objects, such as a tree. Similarly, those skilled in the art will appreciate that the flood light 10 having asymmetric reflector 12 is also adaptable for producing substantially uniform illumination over a selected horizontal area, such as the illumination of a parking lot surface by a flood light located near the lot perimeter, illumination of an auditorium or atrium floor by a flood light located on a wall, and similar lighting applications.
FIG. 2 through FIG. 6 show an isometric view, a top view, a front view, a side view, and a rearward isometric view, respectively, of the exemplary reflector 12 that suitably practices an embodiment of the invention. The reflector 12 is approximately rectangular when viewed from the front (FIG. 4 ), and is bilaterally symmetric about a symmetry plane 32 which defines a left side 34 and a right side 36 , as best seen in FIGS. 3 and 4. The reflector 12 additionally has a top 38 and a bottom 40 , as best seen in FIGS. 3, 4 , and 5 , and a forward side 42 and a rearward side 44 , as best seen in FIGS. 3 and 5. A forward opening 46 is provided from which lamp light is emitted, and the reflector 12 as a whole defines a lamp space 48 .
An associated lamp (not shown), which can be a halogen lamp, an incandescent lamp, a metal halide lamp, or other light emitting element, occupies the lamp space 48 , i.e. the lamp is arranged inside the reflector 12 . In a preferred embodiment for outdoor lighting applications, a relatively high power lamp, e.g. preferably greater than 200 watts input power although the reflector may also be used with lamps of lower wattage, is arranged in vertical fashion in the lamp. The lamp is preferably of the type having a threaded end fastener, e.g. a “screw-in” bulb, in which the threaded fastener has integral electrical connections so that the bulb can be screwed into a lamp socket (not shown) positioned in a lamp socket port 50 to simultaneously effectuate both physical fastening of the light bulb within the reflector 12 and electrical connection of the light bulb to a power supply (not shown). Although in the reflector embodiment shown in FIGS. 2 through 6 the lamp socket port 50 is arranged on the top 38 of the reflector 12 , other locations for the lamp socket port are also contemplated, such as locating it on the bottom 40 of the reflector 12 .
With reference back to FIG. 1, the operation of the flood light 10 is as follows. The lamp (not shown) generates light essentially emanating from a spatial point, e.g. a spatial point corresponding to a glowing filament or arc tube location. The light is typically emitted roughly uniformly in all directions, albeit with some directionality typically imposed, for example by shadowing produced by the socket. The reflector 12 reflects the generated light to form an expanding rectangular light beam 24 that impinges on the wall 14 to illuminate the rectangular area 20 . The expanding rectangular light beam 24 is characterized by an azimuth angle AA and a lateral divergence angle AL which are determined by the detailed surface curvatures of the reflector 12 .
In the embodiment illustrated in FIGS. 2 through 6, the reflector 12 comprises a metal form defining several reflective sub-surfaces. With particular reference to FIGS. 2 and 4, these reflective sub-surfaces include a forward reflector surface 60 , a rearward reflector surface 62 , three essentially planar reflective connecting regions 64 , a top essentially planar reflecting surface 66 , and a bottom essentially parabolic reflecting surface 68 . The rear reflector 62 is essentially parabolic in shape, and is connected by the three planar reflective connecting regions 64 to the top planar reflecting surface 66 and to the forward parabolic reflector 60 . The forward reflector 60 is defined by the symmetric sides 34 , 36 of the reflector 12 , and is also essentially parabolic in shape. The reflector 12 portions that define the top planar reflecting surface 66 and the bottom parabolic reflecting surface 68 join with those defining the forward and rear reflectors 60 , 62 and the planar connecting regions 64 to form a single, continuous, reflective metal sheet that is formed, for example, by a hydroform press. Because the sub-surfaces 60 , 62 , 64 , 66 , 68 are formed from a single reflective metal sheet in a single forming step, they advantageously have a single, continuous, undifferentiated surface finish. In contrast, the segmented asymmetric reflectors of the prior art can have different surface finishes for the various reflector segments, and additional optical discontinuities can arise at the interconnection of the reflector segments.
As is known to those skilled in the art, light emanating from a point light source positioned near the focus of a parabolic reflector is typically collimated into a beam with a divergence that is determined by the precise spatial positioning of the point light source relative to the parabolic focus. The diverging, substantially rectangular output light beam 24 of the flood light 10 is generated by a superposition of the following contributions: (1) light approximately collimated by the forward and rear parabolic reflectors 60 , 62 which are directed in lateral crossing patterns; (2) light approximately collimated by the bottom parabolic reflector 68 that is directed toward the distal portion 26 of the asymmetrically situated rectangular illumination area 20 , i.e. that is directed upward toward the top of the area 20 in the exemplary wall illumination of FIG. 1; (3) minimal light reflected off the three connecting reflective planar regions 64 and directed to the forward parabolic reflectors 46 ; (4) light reflected off the top planar reflective surface 66 which minimally contributes to the light output by spreading the upwardly directed light; and (5) direct lamp illumination that passes through the forward opening 46 , without first impinging upon the reflector 12 . The contributions (1), (2), and (4) are partially collimated by the parabolic reflectors, while the contributions (3) and (5) are partially collimated by aperturing of the forward opening 46 .
As will be recognized by those skilled in the art, the extent and detailed curvature of the reflective surfaces 60 , 62 , 64 , 66 , 68 , the relative position of the lamp, and the detailed dimensions of the forward opening 46 can be calculated, e.g. using photometric distribution simulations, to obtain an optimized reflector geometry that produces a substantially rectangular diverging beam 24 . In a preferred embodiment, a reflector essentially similar to the reflector 12 was designed around a reduced jacket (ED- 28 ) metal halide lamp of about 200 watts or more, and in one embodiment 400 watts, in an essentially vertical orientation. The forward and rear parabolic reflector portions 60 , 62 were designed to give peak luminous intensity at a lateral angle AL (FIG. 1) of between about 50° and 70°, and in one preferred embodiment about 60°. The reflector portions were arranged such that the peak luminous intensity in the plane AL=0° was located at a vertical angle AA of between about 30° and 40°, and in one preferred embodiment about 35°. The asymmetry in luminous intensity distribution improves the uniformity of the illumination, enables the tilt angle AT to be minimized and provides greater amount of light to the surface of interest. The top planar reflective surface 66 was oriented to reflect and spread the upwardly directed light, and the three connecting reflective planar regions 64 were angled in toward the lamp at approximately 15°. With the tilt angle AT set to 35°, it was calculated that this designed reflector would illuminate an essentially rectangular area having a vertical Y dimension of 1.33 MD, and a horizontal X dimension of 4 MD with an intensity maximum-to-minimum uniformity ratio of less than 6-to-1 and an intensity average-to-minimum ratio of less than 3-to-1. The designed reflector was estimated to deliver 24% more illumination to the rectangular area as compared with a similar segmented reflector of the prior art.
In addition to improved performance, the reflector 12 has the advantage of being produced by a simplified manufacturing process. The entire reflector is formed as a single piece using only one hydroform press operation, thus eliminating the post-formation assembly required of prior art segmented asymmetric distribution reflectors. As is known to those of ordinary skill in the art, the hydroform press uses a male punch element machined to match the inside dimensions of the piece to be formed, e.g. in the instant case machined to match the inside dimensions of the reflector 12 . An aluminum or other metal blank which is to be worked or formed is loaded into the hydroform press between the punch element and a flexible diaphragm that seals a pressurized forming chamber. A blank-holding ring is typically pressed down to hold the blank in place around its edges. As the press drives the punch element into the blank, the metal wraps around and deforms to match the surface of the punch element. The pressurized forming chamber is pressurized by a fluid such as oil so that the flexible diaphragm presses against the worked metal to provide a spatially uniform counter-force for maintaining the worked metal in contact with the punch element uniformly across the pressed area of the blank. The uniform counter-force provided by the flexible diaphragm ensures a close match between the punch element surface structure and the corresponding formed piece, e.g. the reflector 12 , and also reduces formation of structural defects in the formed piece, such as surface abrasions, draw marks, and non-uniformly stressed areas.
After the hydroforming step, the lamp socket port 50 and any mounting brackets are cut out, and the unformed portions of the blank are trimmed off. In some cases, mounting structures can be integrally formed during the hydroforming step, and the lamp socket port 50 can be structurally defined as well during the hydroforming to facilitate its removal.
With reference to FIG. 7, an exemplary hydroform punch 80 for forming the reflector 12 is shown. The punch 80 includes a surface 82 that has been machined to match the inside dimensions of the reflector 12 . The surface 82 also includes a structure 84 corresponding to the lamp socket port 50 . The punch 80 further includes a shank 86 for mounting the punch 80 in the hydroform press.
The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
|
An asymmetric flood light includes a reflector comprised of a hydroformed continuous metal form which defines a lamp space adapted to receive a lamp. The reflector has a forward opening for outputting light generated by the associated lamp. The reflector further includes a rear reflector section arranged rearward of the lamp space and adapted to reflect backward-directed lamp illumination forward in a crossing pattern, a forward reflector section disposed forward of the rear reflector section and adapted to reflect lamp illumination forward in a crossing pattern, and a plurality of planar surfaces that connect the forward and rear reflector sections. The hydroformed reflector is adapted to cooperate with the lamp to produce a substantially rectangular area of substantially uniform illumination that is asymmetrically disposed relative to the reflector.
| 5
|
BACKGROUND OF THE INVENTION
Although squid has excellent food value, it has not been extensively marketed in some areas due to the fact that the procedure for cleaning a squid is not generally known by average consumers in the area. Also, most commercial fish suppliers must use a manual, relatively inefficient method of preparing the squid which involves removing the head, eyes, skin, viscera, ink sac, and backbone from the mantle of the squid. Some attempts have been made to mechanize the squid cleaning operation and one of them is disclosed in the patent to Singh U.S. Pat. No. 4,285,099. In that device, each squid is automatically fed to a platform and oriented on the platform under a pair of rotating cutters that are then moved across the squid to divide it into three parts, namely, the mantle, the eye, and the tentacles. Means is also provided for discharging the eye and the tentacles and positioning the mantle on a rapidly rotating peg to dislodge the inner organs of the squid and subjecting the exterior surface to a stream of water to remove skin and fins. The present invention involves a machine that handles squid in a similar manner but does so with mechanisms that operate entirely differently than the mechanisms of Singh. A patent to Berk U.S. Pat. No. 3,947,921 discloses a mechanism for pulling the head and the attached viscera from the mantle of a squid. A squid process machine is also disclosed in the patent to Olsson U.S. Pat. No. 4,329,761.
Other patents disclosing mechanisms that are similar in some respects are the patents to Youman U.S. Pat. No. 1,900,267; to Youman U.S. Pat. No. 1,853,328; to Schlichting U.S. Pat. No. 2,835,918 and to Hogan U.S. Pat. No. 3,670,363.
An object of the present invention is to provide an improved method and apparatus for processing a squid in a continuous operation that begins with the receiving of a whole squid and ends with the discharge of a cleaned and skinned mantle.
SUMMARY OF THE INVENTION
An individual squid is received in an elongate carrier of an endless chain conveyor in an oriented position so that, during further advancement of the conveyor, the squid is brought into engagement with two rotating cutters that divide the squid into three parts, namely, the mantle, the eye and the tentacles. After the eye and the tentacles have been discharged, the mantle is transferred onto a rotatable peg. As the peg rotates, jets of water strip the skin from the mantle and flush loosened internal parts from inside the mantle before the mantle is forced from the peg into a suitable receptacle.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary diagrammatic perspective of the machine of one embodiment of the machine of the present invention.
FIG. 2 is a fragmentary, enlarged vertical section taken longitudinally of the machine along line 2--2 of FIG. 1.
FIG. 3 is an enlarged diagrammatic section taken along line 3--3 of FIG. 1. FIG. 4 is an enlarged diagrammatic section taken along line 4--4 of FIG. 1.
FIG. 5 is an enlarged diagrammatic section taken along line 5--5 of FIG. 1.
FIG. 6 is a fragmentary diagrammatic perspective of a second embodiment of the machine of the present invention, the view being similar to FIG. 1 but showing only the discharge end of the feed conveyor and the turret to which squid are transferred.
FIG. 7 is a diagrammatic section taken along line 7--7 of FIG. 6.
DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1 the reference numeral 20 indicates generally a portion of the squid processing machine of the present invention which includes a pair of parallel conveyors 21 and 22 having endless chains 21a and 22a respectively. Chain 21a is trained around an idler sprocket 23 and a drive sprocket 24 to which a shaft 25 is keyed. Chain 22a is trained around an idler sprocket 26 and a drive sprocket 27 that is keyed to a shaft 28. At one end, each of the shafts 25 and 28 is keyed to a sprocket 29 that is engaged by a chain 30 which is driven by a motor 30a by a belt and pulley 30b and sprocket 30c. Since the two sprockets 29 are of the same size, the shafts 25 and 28 will be rotated at the same speed in counterclockwise directions (FIG. 1). Also, the size of the sprockets 23, 24, 26 and 27 are so chosen that the upper runs of the chains 21a and 22a will be advanced from right to left (FIGS. 1 and 2) at the same speeds in the same horizontal plane. Accordingly, elongate generally U-shaped trough-like carriers 31 carried by the chains are advanced from right to left, with each carrier on chain 21a being aligned longitudinally with a carrier on chain 22a to form a long composite squid-receiving trough.
As seen in FIG. 3, each carrier 31 has a U-shaped bracket 32 brazed to its undersurface, and each depending leg of the bracket is secured to a link 33 of the associated chain 21a or 22a.
The drive shafts 25 and 28 are rotatably journalled in a conventional support frame 34 (FIG. 1) which supports a bar 35 that extends longitudinally of the conveyors between the carriers 31 in the upper runs of the conveyors. The support bar 35 extends from the feed end X to a point below two circular cutting blades 37 and 38 which are disposed generally parallel to the chains 21a and 22a at an elevation such that, as seen in FIG. 3, the lower peripheral portions of the blades are below and on opposite sides of the upper surface of the support bar 35. Both blades are driven by a shaft 39 that is rotated by a motor 40 through a belt drive 41.
As mentioned above, the present machine is particularly adapted to process squid and, as indicated in FIG. 3, a squid has three parts, a mantle M, a head H, and tentacles T. In the use of the machine, a squid is placed in each set of aligned carriers 31 at the feed end X with the mantle M (FIG. 3) in the carrier of conveyor 21, the tentacles T in the associated carrier of conveyor 22, and the head H generally on the flat, upper support surface of the bar 35, with a raised annular portion M1 of the mantle M overlying the edge of the carrier of conveyor 21 at a point to the left of the support bar. It will be noted that the support surface of the bar 35 is at an elevation slightly above the elevation of the support surfaces of the carriers so that a ledge is provided obstructing movement of a squid, longitudinally of the carriers. As each squid is carried toward the cutters 37 and 38, it passes a nozzle 39a which directs a stream of water at the end of the mantle M of the squid, causing the squid to move to the right (FIG. 3) until a portion of the ring M1 of the mantle engages the ledge provided by the bar 35. When the ring M1 engages the ledge, the movement of the squid is stopped, with the squid in proper position relative to the cutting planes of the blades 37 and 38. Accordingly, as the squid advances further toward the left (FIG. 1) it is severed into three sections by the blades. Since the support bar terminates at a point slightly on the downstream side of the axis of rotation of the blades as seen in FIG. 2, the severed head section H moves over the end of the support bar and, aided by a downwardly-directed jet of water from nozzle 39b, drops into a take-away chute 41 as the mantle M and tentacles T are carried along by the carriers 31. Nozzles 39c, that are downstream from nozzle 39b, direct water on the cutters 37 and 38 to keep them clean.
The conveyor 22 is not as long as conveyor 21 and therefore the tentacles T are discharged next into a take-away chute 42 (FIG. 2) disposed below the downstream end of conveyor 22 in a position to receive each tentacle as it is discharged.
After its associated tentacle has been discharged, each mantle M is carried to the end of conveyor 21 where it becomes aligned with one of a plurality of identical cleaning pegs 45 (FIG. 5) carried on another conveying means in the form of a turret 46. When the mantle is in alignment with the cleaning peg, a blast of water from a nozzle 44 (FIG. 1) is directed generally longitudinally of the carrier to move the mantle lengthwise of its carrier onto the peg. The turret includes a cylindrical plate 47 (FIG. 4) that has a central cylindrical opening 48 therethrough. A circular support plate 49 is welded to one face of the plate 47 with a central cylindrical opening 50 in plate 49 concentric with the axis of the cylindrical plate 47. A drive shaft 52, that is journalled near each end in the support frame, is pinned to the support plate 49 by a tapered pin 51 so that rotation of shaft 52 causes rotation of the two plates 49 and 47. As seen in FIG. 1, a sprocket 53, which is keyed to shaft 52, is rotated by the chain 30 that drives the sprockets 29 of the feed conveyors.
Near its periphery, the cylindrical plate 47 is provided with a plurality of cylindrical openings 55 that are equi-angularly spaced around the axis of the turret (FIG. 5), each opening receiving a tubular metal sleeve 56 (FIG. 4) pressed therein. A pair of spaced plastic sleeves 57, that are disposed in the bore of each sleeve, rotatably journal one of cleaning pegs 45, each of which has a small planet gear 60 secured to one end. Each planet gear 60 is in mesh with a sun gear 61 that is secured to a sleeve 62 that rotates around the axis of shaft 52 on a bushing 63. A pulley 64 is keyed to one end of the sleeve 62 and, as seen in FIG. 1, a belt 66 is trained around the pulley 64 and around a pulley 67 that is driven from a motor 68 through a second belt and pulley drive 69. The drive arrangement is such that the belt 66 drives the pulley 64 and the sun gear 61 in a clockwise direction. Since the planet gears 60 are also carried in a clockwise direction by the turret but at a slower rotary speed, the planet gears and the attached cleaning pegs 45 are rotated in a counterclockwise direction about their own axes.
Each cleaning peg 45 consists of a forward portion 45a (FIG. 4) that is threaded on the end of a shank 45b which is keyed to the planet gear 60. The forward portion has a rounded nose 45c, a central passage 45d, and plurality of rearwardly slanted apertures 45e that are arranged to deliver flushing water from the passage 45d to the exterior of the peg. Each shank 45b has a central passage that communicates with the passage 45d and, by means of two radial passages 70, with an annular chamber 72 in the sleeve 56. A plurality of radial passages 71, some of which are shown in FIG. 5, are provided in the turret, each passage communicating with the annular chamber 70 in one of the sleeves 56. At its inner end, each radial passage alternately comes into flow communication with one of two peripheral chambers 73 or 74 (FIG. 3) in a stationary cylindrical valve block 75 that is disposed in the central opening 48 of the turret. The valve block is held in place by a tubular housing 76 (FIG. 4), which may be made of a general rigid plastic material, and is secured at one end to the valve block and, at the other end, to an upright support wall 80 that is rigidly supported from the frame of the machine. A copper pipe 81, which extends through the wall 80, is connected at one end to a source of water under pressure and, at the other end, extends into the valve block 75 where it communicates with the peripheral chamber 73. Similarly, a copper tube 82 establishes flow communication between a source of water and the peripheral chamber 74 in the valve block. The arrangement is such that water is continually supplied to the peripheral chambers 73 and 74. Accordingly, as the turret rotates, each radial passage 71 moves into alignment with chamber 73, causing water to move out along the radial passage, into the annular chamber 72 in the associated sleeve 56, and then into the cleaning peg 45 for discharge through the backwardly-inclined passages 45e. When the radial passage 71 moves out of registry with the chamber 73, the flow of water to the cleaning peg stops but it begins again when the radial passage moves into registry with the chamber 74. Seal rings are disposed between the turret and each sleeve 56 on each side of the chamber 70 of the sleeve, and between the rotating turret and the valve block 75 to prevent escape of water as it flows toward the cleaning peg.
Referring to FIG. 5, each cleaning peg comes into longitudinal alignment with the mantle of a squid at angular position A. At this time the radial passage 71 that brings water to that particular cleaning peg is in registry with the chamber 74. It will be evident from FIG. 4 that, as a mantle is urged onto the unsupported end of a cleaning peg by nozzle 44, the rearwardly inclined streams of water ejected through the slanted openings 45e aid in urging the mantle into impaled position on the rotating peg.
As the rotation of the turret continues, the water to the inside of the peg is stopped at angular position B and the squid mantle comes into range of jets of water ejected from a plurality of nozzles 85 that are mounted on a suitable support adjacent the turret. The nozzles are spaced angularly around the axis of the turret so that their jets successively engage the rapidly rotating squid in overlapping areas. Also the nozzles 85 are in different vertical planes spaced longitudinally of the axis of the turret. As a result, all surfaces of the squid are engaged, and the fins and skin are stripped from the squid.
At angular position C, the cleaning peg carries the squid into a passage defined by an inner, partially cylindrical wall 87 and a series of pressure plates 88 secured to an outer partially cylindrical wall 89. As seen in FIG. 4, the inner wall 87 is supported from the upright wall 80 and the outer wall 89 is supported from the inner wall. The pressure plates are made of a resilient material, such as thin leaf spring plate material, and are so positioned that the squid mantle is gripped between each plate and the inner wall 87. As a result, the rotation of the mantle with the rotating peg is retarded, and the peg rotates relative to the inside of the mantle to help loosen the internal members of the squid such as the viscera and the backbone. Also at angular position C, the radial passage 71 moves into registry with chamber 73 so that water is again ejected outwardly through the angled passages 45e of the peg to flush the loosened internal members out of the cavity of the mantle. At about angular position D, the mantle moves out of engagement with the last hold-down plate and the radial passage 71 moves out of registry with the chamber 73 shortly thereafter. At angular position E, the mantle of the squid is pushed axially from the peg by a blast of water from a nozzle 90 (FIG. 1) that is supported on the drive side of the turret adjacent angular position E. The nozzle 90 is oriented at a slight angle relative to the axis of the turret so that the blast of water leaving the nozzle has a component of force extending longitudinally of a cleaning peg at position E. Accordingly, the jet of water from the nozzle effectively engages the mantle on the peg and forces it from the peg into a suitable receptacle.
It will be evident that the water supply system can be arranged to direct water continuously from the squid positioning nozzle 44, the skinning nozzles 85 and the squid-ejecting nozzle 90. Alternately, the system could include a series of valves that are opened and closed by cams in timed relation with the angular movement of the turret so that water is directed out of the nozzles 44, 85 and 90, or any one of them, only when desired.
In FIGS. 6 and 7 an embodiment of the squid processing machine of the present invention is shown in which the turret and the conveyor that carries the squid mantles are driven from a common shaft to facilitate transfer of each mantle from a bucket of the conveyor to a cleaning peg of the turret. Many of the parts of the embodiment of FIGS. 6 and 7 are identical to parts of the machine of FIGS. 1-5 and these parts will be given the same reference numerals as in FIGS. 1-5, followed by a prime suffix.
The mantle conveyor 21' of FIG. 6 is mounted alongside and parallel to a companion conveyor (not shown) that is identical to conveyor 22 of FIG. 1. Accordingly, whole squid that are positioned one by one on the two conveyors, straddle the space between the conveyors so that synchronized movement of the conveyors moves the squid past a positioning water jet, and then under a pair of circular rotary cutters that sever the central part of the squid from the mantle which remains on the conveyor 21' and from the tentacles which remain in the other conveyor. The central portion of the squid and the tentacles are discharged into separate receptacles as in the apparatus of FIGS. 1-5, while each mantle is conveyed along in a separate carrier 31' of conveyor 21' to a transfer station, that is indicated in FIG. 7 as angular position A', where the carrier comes into longitudinal alignment with one of the cleaning pegs 45' on the turret 46'. As in the arrangement of FIG. 4, the shaft 52' that is keyed to the turret 46', is journalled for rotation in the side walls of the frame of the machine and passes through a support wall 80' of the frame that is intermediate the side walls. A drive sprocket 53' is keyed to one end of the shaft 52' and the sprocket 24' at the discharge end of conveyor 21' is keyed to the other end of the shaft 52'. Accordingly, as the chain 30' drives the shaft 52' in a counterclockwise direction (FIG. 6), the turret and the conveyor 21' are actuated simultaneously. Also, the chain 30' drives in a counterclockwise direction a sprocket 29', that is keyed to the drive sprocket of the shorter conveyor. Further, the sun gear 61' is rotated in a clockwise direction by the pulley 64' with the result that the planet gears 60' are rotated about their axes
Referring to FIG. 7 it will be noted that the cleaning pegs 45' on the turret 46' and base of each U-shaped carrier 31' are located at the same radial distance from the axis of the shaft 52', and that the pegs are angularly spaced around the turret to conform with the angular spacing of the carriers. The arrangement is such that each carrier becomes aligned longitudinally with one of the cleaning pegs at angular postion A' where a blast of water from one or more nozzles 44' drive a squid mantle from the carrier onto the cleaning peg.
The valve block 75' is identical to valve block 75 in that it is supported from the support wall 80' by a rigid plastic sleeve and has two angular peripheral chambers 73' and 74' which are continuously supplied with water under pressure by copper tubes 81' and 82' respectively. The valve block 75' differs from block 75 in that it is oriented so that chamber 74' is above chamber 73' as seen in FIG. 7. Chamber 74' extends counterclockwise from about three degrees before top dead center (angular position A') to about 35° past angular position A', while chamber 73' extends counterclockwise from a position about 115° past top center to a position about 260° past top center.
As in the embodiment of FIGS. 1-5, rotation of the turret brings radial passages in the turret consecutively into alignment with the angular chambers 73' and 74', and relative rotation between the turret and the planet gear carrier, which is driven by the belt 66' through pulley 64', causes rotation of the cleaning pegs 45' about their own axes as they move around the axis of shaft 52'.
In operation, just before the turret moves a peg 45' into registry with a carrier 31' at position A' (FIG. 7), the radial passage in the turret that is associated with that peg establishes flow communication with chamber 74'. Accordingly, when a mantle is transferred onto the peg, the jets of water issued from the rearwardly inclined passages in the peg help to move the mantle onto the peg. As the turret continues to rotate, the water delivered to the peg is stopped at angular position B'. Shortly thereafter the mantle on the rotating peg is brought into the range of the jets of water issuing from the nozzles 85' with the result that the fins and skin are removed from the mantle. At angular position C', water is again directed into the cleaning peg as the mantle on the peg moves into engagement with the stationary wall 87' and one of the resilient pressure plates 88'. As the mantle is moved along the arcuate space between the wall 87' and the pressure plates 88', the peg rotates relative to the body of the mantle to loosen the viscera and backbone of the squid, and water issuing from the pegs flushes the loosened parts out of the mantle body. At angular position D', the mantle moves out of engagement with the last pressure plate 88', and the water to the peg is stopped. Shortly thereafter, at position E', the mantle is driven longitudinally off the peg by water jets issuing from one or more nozzles 90', and deposited in a suitable receptacle.
Referring to FIG. 6, it will be noted that the drive mechanisms, including belt 66' and chain 30', of FIG. 6, are oriented in a little different manner than the corresponding parts of FIG. 1. This re-arrangement is due to the use of a common drive shaft for the sprocket 24' and the turret 46'. It will of course be understood that the motors and drive connections for the sun gear 61', shaft 52', shaft 28', and the shaft of the rotary cutters are generally similar to the motors and drive connections of FIG. 1, and are so chosen as to obtain the movement of the various parts in the desired direction and at the desired speeds.
From the foregoing descriptions it will be apparent that the machine of the present invention provides a method for effectively receiving a whole squid and automatically performing all the cutting, skinning, and cleaning oeprations necessary to produce a marketable piece of squid. The unique arrangement whereby, in sequential steps and during continuous movement of the squid, the squid is cut into three sections, two of the sections discharged and the third section transferred to a rotating peg, and the skin is removed from the remaining section and its inner organs are separated from the section, makes the machine particularly effective from a time standpoint while still producing an adequately prepared section of squid.
|
A squid processing method and apparatus includes means for sectionizing squid while they are on a feed conveyor, and then transferring selected sections to a processing conveyor on which each section is skinned and its internal organs separated from the edible portion of the section and flushed away.
| 0
|
CROSS REFERENCE TO RELATED DOCUMENT
The present application is a division of application Ser. No. 09/747,725, now U.S. Pat. No. 6,457,814 B1 which was filed on 20 th Dec. 2000.
THE FIELD OF THE INVENTION
This invention relates to the manufacturer of printheads used in fluid-jet printers, and more specifically to a fluid-jet printhead used in a fluid-jet print cartridge having improved dimensional control and improved step coverage.
BACKGROUND OF THE INVENTION
One type of fluid-jet printing system uses a piezoelectric transducer to produce a pressure pulse that expels a droplet of fluid from a nozzle. A second type of fluid-jet printing system uses thermal energy to produce a vapor bubble in a fluid-filled chamber that expels a droplet of fluid. The second type is referred to as thermal fluid-jet or bubble jet printing systems.
Conventional thermal fluid-jet printers include a print cartridge in which small droplets of fluid are formed and ejected towards a printing medium. Such print cartridges include fluid-jet printheads with orifice structures having very small nozzles through which the fluid droplets are ejected. Adjacent to the nozzles inside the fluid-jet printhead are fluid chambers, where fluid is stored prior to ejection. Fluid is delivered to fluid chambers through fluid channels that are in fluid communication with a fluid supply. The fluid supply may be, for example, contained in a reservoir part of the print cartridge.
Ejection of a fluid droplet, such as ink, through a nozzle may be accomplished by quickly heating a volume of fluid within the adjacent fluid chamber. The rapid expansion of fluid vapor forces a drop of fluid through the nozzle in the orifice structure. This process is commonly known as “firing.” The fluid in the chamber may be heated with a transducer, such as a resistor, that is disposed and aligned adjacent to the nozzle.
In conventional thermal fluid-jet printhead devices, such as ink-jet cartridges, thin film resistors are used as heating elements. In such thin film devices, the resistive heating material is typically deposited on a thermally and electrically insulating substrate. A conductive layer is then deposited over the resistive material. The individual heater element (i.e., resistor) is dimensionally defined by conductive trace patterns that are lithographically formed through numerous steps including conventionally masking, ultraviolet exposure, and etching techniques on the conductive and resistive layers. More specifically, the critical width dimension of an individual resistor is controlled by a dry etch process. For example, an ion assisted plasma etch process is used to etch portions of the conductive and resistive layers not protected by a photoresist mask. The width of the remaining conductive thin film stack (of conductive and resistive layers) defines the final width of the resistor. The resistive width is defined as the width of the exposed resistive perpendicular to the direction of current flow. Conversely, the critical length dimension of an individual resistor is controlled by a subsequent wet etch process. A wet etch process is used to produce a resistor having sloped walls on the conductive layer defining the resistor length. The sloped walls of the conductive layer permit step coverage of later fabricated layers.
As discussed above, conventional thermal fluid-jet printhead devices require both dry etch and wet etch processes. The dry etch process determines the width dimension of an individual resistor, while the wet etch process defines both the length dimension and the necessary sloped walls commencing from the individual resistor. As is well known in the art, each process requires numerous steps, thereby increasing both the time to manufacture a printhead device and the cost of manufacturing a printhead device.
One or more passivation and cavitation layers are fabricated in a stepped fashion over the conductive and resistive layers and then selectively removed to create a via for electrical connection of a second conductive layer to the conductive traces. The second conductive layer is pattered to define a discrete conductive path from each trace to an exposed bonding pad remote from the resistor. The bonding pad facilitates connection with electrical contacts on the print cartridge. Activation signals are provided from the printer to the resistor via the electrical contacts.
The printhead substructure is overlaid with at least one orifice layer. Preferably, the at least one orifice layer is etched to define the shape of the desired firing fluid chamber within the at least one orifice layer. The fluid chamber is situated above, and aligned with, the resistor. The at least one orifice layer is preferably formed with a polymer coating or optionally made of an fluid barrier layer and an orifice plate. Other methods of forming the orifice layer(s) are know to those skilled in the art.
In direct drive thermal fluid-jet printer designs, the thin film device is selectively driven by electronics preferably integrated within the integrated circuit part of the printhead substructure. The integrated circuit conducts electrical signals directly from the printer microprocessor to the resistor through conductive layers. The resistor increases in temperature and creates super-heated fluid bubbles for ejection of the fluid from the fluid chamber through the nozzle. However, conventional thermal fluid-jet printhead devices can suffer from inconsistent and unreliable fluid drop sizes and inconsistent turn on energy required to fire a fluid droplet, if the resistor dimensions are not tightly controlled. Further, the stepped regions within the fluid chamber can affect drop trajectory and device reliability. The device reliability is affected by the bubble collapsing after the drop ejection thereby wearing down the stepped regions.
It is desirous to fabricate a fluid-jet printhead capable of producing fluid droplets having consistent and reliable fluid drop sizes. In addition, it is desirous to fabricate a fluid-jet printhead having a consistent turn on energy (TOE) required to fire a fluid droplet, thereby providing greater control of the size of the fluid drops.
SUMMARY OF THE INVENTION
A fluid-jet printhead has a substrate having at least one layer defining a fluid chamber for ejecting fluid. The printhead also includes a resistive layer disposed between the fluid chamber and the substrate wherein the fluid chamber has a smooth planer surface between the fluid chamber and the substrate. The printhead has a conductive layer disposed between the resistive layer and the substrate wherein the conductive layer and the resistive layer are in direct parallel contact. The conductive layer forms at least one void creating a planar resistor in the resistive layer. The planar resistor is aligned with the fluid chamber.
The present invention provides numerous advantages over conventional thin film printheads. First, the present invention provides a structure capable of firing a fluid droplet in a direction substantially perpendicular (normal or orthogonal) to a plane defined by the resistive element and ejection surface of the printhead. Second, the dimensions and planarity of the resistive material layer are-more precisely controlled, which reduces the variation in the turn on energy required to fire a fluid droplet. Third, the size of a fluid droplet is better controlled due to less variation in resistor size. Fourth, the corrosion resistance, surface texture, and electro-migration resistance of the conductive layers are improved inherently by the design.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged, cross-sectional, partial view illustrating a conventional thin film printhead substructure.
FIG. 2 is a flow chart of an exemplary process used to implement the conventional thin film printhead structure.
FIG. 3A is an enlarged, cross-sectional, partial view illustrating the invention's thin film printhead substructure.
FIG. 3B is an overhead view of the resistor element.
FIG. 4 is a flowchart of an exemplary process used to implement the invention's thin-film printhead structure.
FIG. 5 is a perspective view of a printhead fabricated with the invention.
FIG. 6 is an exemplary print cartridge that integrates and uses the printhead of FIG. 5 .
FIG. 7 is an exemplary recoding device, a printer, which uses the print cartridge of FIG. 6 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.
The present invention is a fluid-jet printhead, a method of fabricating the fluid-jet printhead, and use of a fluid-jet printhead. The present invention provides numerous advantages over the conventional fluid-jet or inkjet printheads. First, the present invention provides a structure capable of firing a fluid droplet in a direction substantially perpendicular (normal or orthogonal) to a plane defined by the resistive element and ejection surface of the printhead. Second, the dimensions and planarity of the resistive layer are more precisely controlled, which reduces the variation in the turn on energy required to fire a fluid droplet. Third, the size of a fluid droplet is better controlled due to less variation in resistor size. Fourth, the design inherently provides for improved corrosion resistance, improved electro-migration resistance of the conductive layers and a smoother resistor surface.
FIG. 1 is an enlarged, cross-sectional, partial view illustrating a conventional thin film printhead 190 . The thicknesses of the individual thin film layers are not drawn to scale and are drawn for illustrative purposes only. As shown in FIG. 1, thin film printhead 190 has affixed to it a fluid barrier layer 70 , which is shaped along with orifice plate 80 to define fluid chamber 100 to create an orifice layer 82 (see FIG. 5 ). Optionally, the orifice layer 82 and fluid barrier layers 70 may be made of one or more layers of polymer material. A fluid droplet within a fluid chamber 100 is rapidly heated and fired through nozzle 90 when the printhead is used.
Thin film printhead substructure 190 includes substrate 10 , an insulating insulator layer 20 , a resistive layer 30 , a conductive layer 40 (including conductors 42 A and 42 B), a passivation layer 50 , a cavitation layer 60 , and a fluid barrier structure 70 defining fluid chamber 100 with orifice plate 80 .
As diagrammed in FIG. 2, a relatively thick insulator layer 20 (also referred to as an insulative dielectric) is applied to substrate 10 in step 110 preferably by deposition. Silicon dioxides are examples of materials that are used to fabricate insulator layer 20 . Preferably, insulator layer 20 is formed from tetraethylorthosilicate (TEOS) oxide having a 14,000 Angstrom thickness. In one alternative embodiment, insulative layer 20 is fabricated from silicon dioxide. In another embodiment, it is formed of silicon nitride.
There are numerous ways to fabricate insulation layer 20 , such as through a plasma enhanced chemical vapor deposition (PECVD), or a thermal oxide process. Insulator layer 20 serves as both a thermal and electrical insulator for the resistive circuit that will be built on its surface. The thickness of the insulator layer can be adjusted to vary the heat transferring or isolating capabilities of the layer depending on a desired turn-on energy and firing frequency.
Next in step 112 , the resistive layer 30 is applied to uniformly cover the surface of insulation layer 20 . Preferably, the resistive layer is tantalum silicon nitride or tungsten silicon nitride of a 1200 Angstrom thickness although tantalum aluminum can also be used. Next in step 114 , conductive layer 40 is applied over the surface of resistive layer 30 . In conventional structures, conductive layer 40 is formed with preferably aluminum copper or alternatively with tantalum aluminum or aluminum gold. Additionally, a metal used to form conductive layer 40 may also be doped or combined with materials such as copper, gold, or silicon or combinations thereof A preferable thickness for the conductive layer 40 is 5000 Angstroms. Resistive layer 30 and conductive layer 40 can be fabricated though various techniques, such as through a physical vapor deposition (PVD).
In step 116 , the conductive layer 40 is patterned with a photoresist mask to define the resistor's width dimension. Then in step 118 , conductive layer 40 is etched to define conductors 42 A and 42 B. Fabrication of conductors 42 A and 42 B define the critical length and width dimensions of the active region of resistive layer 30 . More specifically, the critical width dimension of the active region of resistive layer 30 is controlled by a dry etch process. For example, an ion assisted plasma etch process is used to vertically etch portions of conductive layer 40 which are not protected by a photoresist mask, thereby defining a maximum resistor width as being equal to the width of conductors 42 A and 42 B. In step 120 , the conductor layer is patterned with photoresist to define the resistor's length dimension defined as the distance between conductors 42 A and 42 B. In step 122 , the critical length dimension of the active region of resistive layer 30 is controlled by a wet etch process. A wet etch process is used since it is desirable to produce conductors 42 A and 42 B having sloped walls, thereby defining the resistor length. Sloped walls of conductive layer 42 A enables step coverage of later fabricated layers such as a passivation layer that is applied in step 124 .
Conductors 42 A and 42 B serve as the conductive traces that deliver a signal to the active region of resistive layer 30 for firing a fluid droplet. Thus, the conductive trace or path for an electrical signal impulse that heats the active region of resistive layer 30 is from conductor 42 A through the active region of resistive layer 30 to conductor 42 B.
In step 124 , passivation layer 50 is then applied uniformly over the device. There are numerous passivation layer designs incorporating various compositions. In one conventional embodiment, two passivation layers, rather than a single passivation layer are applied. In the conventional printhead example of FIG. 1, the two passivation layers comprise a layer of silicon nitride followed by a layer of silicon carbide. More specifically, the silicon nitride layer is deposited on conductive layer 40 and resistive layer 30 and then a silicon carbide is preferably deposited. With this design, electromigration of the conductive layer can intrude into the passivation layer.
After passivation layer 50 is deposited, cavitation barrier 60 is applied. In the conventional example, the cavitation barrier comprises tantalum. A sputtering process, such as a physical vapor deposition (PVD) or other techniques known in the art deposits the tantalum. Fluid barrier layer 70 and orifice layer 80 are then applied to the structure, thereby defining fluid chamber 100 . In one embodiment, fluid barrier layer 70 is fabricated from a photosensitive polymer and orifice layer 80 is fabricated from plated metal or organic polymers. Fluid chamber 100 is shown as a substantially rectangular or square configuration in FIG. 1 . However, it is understood that fluid chamber 100 may include other geometric configurations without varying from the present invention.
Thin film printhead 190 , shown in FIG. 1, illustrates one example of a typical conventional printhead. However, printhead 190 requires both a wet and a dry etch process in order to define the functional length and width of the active region of resistive layer 30 , as well as to create the sloped walls of conductive layer 40 necessary for adequate step coverage of the later fabricated layers, such as the passivation 50 and cavitation 60 layers.
FIG. 3 is an enlarged, cross-sectional, partial view illustrating the layers for fluid-jet printhead 200 incorporating the present invention. The thicknesses of the individual thin film layers are not drawn to scale and are drawn for illustrative purposes only. FIG. 5 is an enlarged, plan view illustrating a fluid-jet printhead 200 incorporating the present invention. As shown in FIG. 4 in step 110 , insulative layer 20 is fabricated by being deposited through any known means, such as a plasma enhanced chemical vapor deposition (PECVD), low pressure chemical vapor deposition (LPCVD), atmospheric pressure chemical vapor deposition (APCVD), or a thermal oxide process onto substrate 10 . Preferably, insulator layer 20 is formed from tetraethylorthosilicate (TEOS) oxide of a thickness of 9000 Angstroms. In one alternative embodiment, insulative layer 20 is fabricated from silicon dioxide. In another embodiment, it is formed of silicon nitride.
In step 126 , a dielectric material 44 is deposited onto the insulator layer. This dielectric material 44 is then patterned in step 128 to create a resistor area, and then dry etched in step 130 to form thin-film layers which define the resistor's length dimension L. In one preferred embodiment, dielectric material 44 is formed from silicon nitride of approximately 5000 Angstroms of thickness. In an alternative embodiment dielectric material 44 is fabricated from silicon dioxide or silicon carbide.
In step 114 , conductive material layer 40 is then fabricated on top of insulative layer 20 and abuts the etched dielectric material 44 to form the resistor length L. In one embodiment, conductive material layer 40 is a layer formed through a physical vapor deposition (PVD) from aluminum and copper of approximately 5000 Angstrom of thickness. More specifically, in one embodiment, conductive material layer 40 includes up to approximately two percent copper in aluminum, preferably approximately 0.5 percent copper in aluminum. Utilizing a small percent of copper in aluminum limits electro-migration. In another preferred embodiment, conductive material layer 40 is formed from titanium, copper, or tungsten.
In step 132 , a photoimagable masking material such as photoresist is deposited on portions of conductive layer 40 , thereby exposing other portions of conductive layer 40 .
In step 134 , the top surface of conductive layer 40 is then planarized such that the top surface of dielectric material 44 is level with the top surface of conductive layer 40 . In one preferred embodiment, the top surface of conductive layer 40 is planarized through use of a resist-etch-back (REB) process. In another embodiment, the top surface of conductive layer 40 is planarized through use of a chemical/mechanical polish (CMP) process.
Next in step 112 , the resistive layer 30 is applied to uniformly cover the surface of the entire surface of substrate 10 and previously applied layers (wafer surface). Preferably, the resistive layer 30 is tungsten silicon nitride of a 1200 Angstrom thickness although tantalum aluminum, tantalum, or tantalum silicon nitride can also be used
In step 116 , a photoimagable masking material is deposited on the previously applied layers on the substrate surface. The photoimagable masking material is removed where the combined resistive layer 30 and conductive layer 60 are to be etched to define respectively the resistor width W and conductors 42 A and 42 B.
In step 136 , the exposed portions of resistive layer 30 and conductive layer 40 are removed through a dry etch process, several of which are known to those skilled in the art such as described in step 118 of FIG. 2 . This etching step defines and forms the resistor width. The photoresist mask is then removed, thereby exposing an exemplary substantially rectangular-shaped conductors 42 A and 42 B. The passivation 50 , cavitation 60 , barrier 70 and orifice 80 layers are then applied as described for the conventional printhead.
Conductors 42 A and 42 B provide an electrical connection/path between external circuitry and the formed resistive element. Therefore, conductors 42 A and 42 B transmit energy to the formed resistor to create heat capable of firing a fluid droplet positioned on a top surface of the formed resistive element in a direction perpendicular to the top surface of the resistive element.
As shown in FIG. 3B, conductors 42 A and 42 B define a resistor element 46 between conductors 42 A and 42 B. Resistive element 46 has a length L equal to the distance between conductors 42 A and 42 B. Resistive element 46 has a width W. However, it is understood that resistive element 46 may be fabricated having any one of a variety of configurations, shapes, or sizes, such as a thin trace or a wide trace of conductors 42 A and 42 B. The only requirement of the resistive element 46 is that it contacts conductors 42 A and 42 B to ensure a proper electrical connection. While the actual length L of resistive element 46 is equal to or greater than the distance between the outer most edges of conductors 42 A and 42 B, the active portion of resistive element 46 which conducts heat to a droplet of fluid positioned above resistive element 46 corresponds to the distance between the outermost edges of conductors 42 A and 42 B.
In FIG. 5, each orifice nozzle 90 is in fluid communication with respective fluid chambers 100 (shown enlarged in FIG. 2) defined in printhead 200 . Each fluid chamber 100 is constructed in orifice structure 82 adjacent to thin film structure 32 that preferably includes a transistor coupled to the resistive component. The resistive component is selectively driven (heated) with sufficient electrical current to instantly vaporize some of the fluid in fluid chamber 100 , thereby forcing a fluid droplet through nozzle 90 .
Exemplary fluid-jet print cartridge 220 is illustrated in FIG. 6 . The fluid-jet printhead device of the present invention is a portion of fluid-jet print cartridge 220 . Fluid-jet print cartridge 220 includes body 218 , flexible circuit 212 having circuit pads 214 , and printhead 200 having orifice nozzles 90 . Fluid-jet print cartridge 220 has fluid-jet printhead 200 in fluidic connection to fluid in body 218 using a fluid delivery system 216 , shown as a sponge to provide backpressure using capillary action in the sponge (preferably closed-cell foam) to prevent leakage of fluid though orifice nozzles 90 when not in use. While flexible circuit 212 is shown in FIG. 6, it is understood that other electrical circuits known in the art may be utilized in place of flexible circuit 212 without deviating from the present invention. It is only necessary that electrical contacts 214 be in electrical connection with the circuitry of fluid-jet print cartridge 220 . Printhead 200 having orifice nozzles 90 is attached to the body 218 and controlled for ejection of fluid droplets, typically by a printer but other recording devices such as plotters, and fax machines, too name a couple, can be used. Thermal fluid-jet print cartridge 220 includes orifice nozzles 90 through which fluid is expelled in a controlled pattern during printing. Conductive drivelines for each resistor component are carried upon flexible circuit 212 mounted to the exterior of print cartridge body 218 . Circuit contact pads 214 (shown enlarged in FIG. 6 for illustration) at the ends of the resistor drive lines engage similar pads carried on a matching circuit attached to a printer (not shown). A signal for firing the transistor is generated by a microprocessor and associated drivers on the printer that apply the signal to the drivelines.
FIG. 7 is an exemplary recording device, a printer 240 , which uses the exemplary fluid-jet print cartridge 220 of FIG. 6 . The fluid-jet print cartridge 220 is placed in a carriage mechanism 254 to transport the fluid-jet print cartridge 220 across a first direction of medium 256 . A medium feed mechanism 252 transports the medium 256 in a second direction across fluid-jet printhead 220 . Medium feed mechanism 252 and carriage mechanism 254 form a transport mechanism to move the fluid-jet print cartridge 220 across the first and second directions of medium 256 . An optional medium tray 250 is used to hold multiple sets of medium 256 . After the medium is recorded by fluid-jet print cartridge 220 using fluid-jet printhead 200 to eject fluid onto medium 256 , the medium 256 is optionally placed on media tray 258 .
In operation, a droplet of fluid is positioned within fluid chamber 100 . Electrical current is supplied to resistive element 46 via conductors 42 A and 42 B such that resistive element 46 rapidly generates energy in the form of heat. The heat from resistive element 46 is transferred to a droplet of fluid within fluid chamber 100 until the droplet of fluid is “fired” through nozzle 90 . This process is repeated several times in order to produce a desired result. During this process, a single dye may be used, producing a single color design, or multiple dyes may be used, producing a multicolor design.
The present invention provides numerous advantages over the conventional printhead. First, the resistor length of the present invention is defined by the placement of dielectric material 44 that is fabricated during a combined photo process and dry etching process. The accuracy of the present process is considerably more controllable than conventional wet etch processes. More particularly, the present process is in the range of 10-25 times more controllable than a conventional process. With the current generation of low drop weight, high-resolution printheads, resistor lengths have decreased from approximately 35 micrometers to less than approximately 10 micrometers. Thus, resistors size variations can significantly affect the performance of a printhead. Resistor size variations translate into drop weight and turn on energy variations across the resistor on a printhead. Thus, the improved length control of the resistive material layer yields a more consistent resistor size and resistance, which thereby improves the consistency in the drop weight of a fluid droplet and the turn on energy necessary to fire a fluid droplet.
Second, the resistor structure of the present invention includes a completely flat top surface and does not have the step contour associated with conventional fabrication designs. A flat structure (smooth planar surface) provides consistent bubble nucleation, better scavenging of the fluid chamber, and a flatter topology, thereby improving the adhesion and lamination of the barrier structure to the thin film. Third, due to the flat topology of the present structure, the barrier structure is allowed to cover the edge of the resistor. By introducing heat into the floor of the entire fluid chamber, fluid droplet ejection efficiency is improved.
Third, because there is no wet slope etch process used in the fabrication of the invention, slope roughness, and conductive layer residue on the resistive layer are no longer issues.
Fourth, due to the encapsulation and cladding of conductive layer 40 by resistive layer 30 , electro-migration of the conductive layer 40 is minimized into the passivation layer.
Further, by attaching the printhead 200 to the fluid cartridge 220 , the combination forms a convenient module that can be packaged for sale.
Although specific embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations calculated to achieve the same purposes may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. Those with skill in the chemical, mechanical, electromechanical, electrical, and computer arts will readily appreciate that the present invention may be implemented in a very wide variety of embodiments. This application is intended to cover any adaptations or variations of the preferred embodiments discussed herein. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.
|
A fluid-jet printhead has a substrate having at least one layer defining a fluid chamber for ejecting fluid. The printhead also includes a resistive layer disposed between the fluid chamber and the substrate wherein the fluid chamber has a smooth planer surface between the fluid chamber and the substrate. The printhead has a conductive layer disposed between the resistive layer and the substrate wherein the conductive layer and the resistive layer are in direct parallel contact. The conductive layer forms at least one void creating a planar resistor in the resistive layer. The planar resistor is aligned with the fluid chamber.
| 8
|
BACKGROUND OF THE INVENTION
The present invention relates to an attachment for a sewing machine, and more particularly to an overcasting attachment for use with a sewing machine which is prepared for straight stitching, wherein needle-like thread guide pieces are provided for passing an additionally prepared thread or threads from sideways around the needle point at a suitable time, making use of the vertical reciprocating movement of the needle, so as to engage the thread or threads with the sewing machine threads for straight stitching.
SUMMARY OF THE INVENTION
According to the present invention, there is provided an overcasting attachment for use with a sewing machine having a needle bar provided with a needle. The inventive attachment comprises a base plate having an end wall at a part of one lateral end thereof; an L-shaped actuating lever pivoted intermediate the ends thereof to the end wall and having one end thereof slidably pivoted to the needle bar for substantially vertical swinging movement with the needle bar, the other end of the L-shaped actuating lever being movable transversely in a substantially horizontal plane; a transverse-horizontal swing plate operatively connected at one end to the other end of the L-shaped actuating lever for transverse swinging movement in a substantially horizontal plane, the other end of the transverse-horizontal swing plate being pivoted to the base plate at the opposite end remote from the end wall, the transverse-horizontal swing plate having a plurality of transversely deformed elongated slots; a plurality of longitudinal swing members each pivotally connected intermediate the ends thereof to the base plate and having at one end thereof a shanked roller pin slidably engageable with the respective one of the deformed slots; the longitudinal swing members being movable longitudinally in a substantially horizontal plane in acoordance with the respective contour of each of the deformed slots; and at least one needle-like thread guide piece connected to the other end of one of said longitudinal swing members for guiding at least one individually prepared cross thread. With this arrangement, when the L-shaped actuating lever swings in accordance with the vertical reciprocating movement of the needle bar, the respective movement of each of the longitudinal swing members is applied sideways toward the needle at a suitable time during the vertical reciprocating movement of the needle in such a manner that the needle-like thread guide piece guides the individually prepared cross thread to engage the sewing machine threads for straight stitching on the upper and lower surfaces of a cloth so as to produce overcasting stitches. In one embodiment, a thread pulling lever pulls and feeds back the thread at a suitable time in accordance with the vertical reciprocating movement of the needle so that the thread guide piece may pull and feed back the thread while at the same time accomplishing longitudinal swinging movement. In another embodiment, two thread guide pieces are provided, one for an upper cross thread and the other for a lower cross thread. Each of the thread guide pieces has a crooked end on which the cross thread may be carried in a manner forming a bow-shaped configuration with the crooked end so that the needle may pass through the inside of the bow-shaped configuration to ensure engagement of the cross thread with the sewing machine threads.
Accordingly, it is the primary object of the present invention to provide a unique overcasting attachment which is attached to a usual sewing machine to automatically produce overcasting stitches at high speeds.
The present invention will become more fully apparent from the claims and the description as it proceeds in connection with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an attachment according to one embodiment of the present invention applied to a sewing machine;
FIG. 2 is a plan view of the attachment with the cover and several parts removed for purposes of illustration;
FIG. 3 is a left side elevational view of the attachment with the cover and several parts removed for purposes of illustration;
FIG. 4 is a front view of the attachment with the cover and several parts removed for purposes of illustration;
FIG. 5 is a front view in which guide pieces for upper and lower cross threads are disposed at the rightmost position and the threads begin to be engaged with each other;
FIG. 6 is a front view in which the guide pieces begin to move to the left and the upper cross thread is passing beneath the lower one;
FIG. 7 is a front view in which the guide pieces have advanced to the leftmost position and the upper and lower cross threads are engaged with the needle on the upper and lower surfaces of the cloth, respectively, when the needle has passed through the cloth to the lowermost position;
FIG. 8 is a plan view illustrating the overcasting formation through engagement of the upper and lower cross threads with threads for straight stitching, when the guide pieces are at the same positions as those in FIG. 6;
FIG. 9 is a plan view in which the needle passes through the arcuate configuration formed by the cross thread, when the guide pieces are at the same positions as those in FIG. 7;
FIG. 10 is a front view in which the extreme end of the thread truing portion serves to support the lower cross thread at a suitable time, to thereby complete four strand stitches;
FIG. 11 is a developed view illustrating the four lock-stitched threads engaged with one another on the upper, lower and side surfaces of the cloth in FIGS. 8 and 9;
FIG. 12 is a view illustrating the overcasting stitches produced around the edge of the cloth by the attachment according to the present invention;
FIG. 13 is a view illustrating a modified configuration of the cross thread guide pieces;
FIG. 14 is a perspective view illustrating a modified configuration of the thread guide portions;
FIG. 15 is a plan view, similar to FIG. 2, of the second embodiment of the present invention; and
FIG. 16 is a view illustrating the improved thread-truing guide member and the cutter means.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 to 4 wherein the first embodiment of the present invention is shown as applied to a sewing machine, reference numeral 1 designates a base plate of the attachment which is of L-shaped configuration in cross section and has an end wall 1'. A fixture 3 is secured to the end wall 1' by set screws 2 and has one end fixedly connected to a presser bar 4 of the sewing machine.
Reference numeral 5 designates an L-shaped actuating lever pivotally connected by a fulcrum pin 6 to the end wall 1' of the base plate 1. The actuating lever 5 has at the extreme end thereof a split opening 5' which is adapted to be engaged with a needle clamp screw 7' of the needle bar 7 for vertical swinging movement.
A connecting lever 9 is carried by the L-shaped actuating lever 5 at the lower portion thereof through a connecting pin 9'. The connecting lever 9 has in the rear portion thereof a connecting aperture 10. There is provided a fan-shaped, transverse-horizontal swing plate 11 having at the extreme end thereof a connecting projection 11'. The connecting projection 11' is engaged with the connecting aperture 10 so as to convert the vertical movement of the needle 8 into the arcuate movement A of the fan-shaped, transverse-horizontal swing plate 11 pivoted to the base plate 1 by a fulcrum pin 12.
The transverse-horizontal swing plate 11 has deformed elongated slots 14, 15, 16 and 17 each having an individual configuration so as to accomplish the operation to suit its respective object. There are provided under the transverse-horizontal swing plate 11 longitudinal swing members 18, 19, 20 and 21 having shanked roller pins 14', 15', 16' and 17' secured thereto in engagement with the slots, respectively, so as to allow the swinging movements of the longitudinal swing members which will be hereinafter described.
Referring to FIGS. 2 and 10, the leftmost longitudinal swing member 18 is mounted by a fulcrum pin 18' to the base plate 1 and has at the extreme end thereof a thread truing portion 18" which is adapted for supporting or releasing an associated, lower cross thread 31 at a suitable time so as to maintain at a constant position the intersection of the lower cross thread 31 with another associated, upper cross thread 30.
With continuing reference to FIG. 2, the second longitudinal swing member 19 is mounted by a fulcrum pin 19' to the base plate 1, and has, at its forward end portion, an arcuate, upper cross thread guide piece 19" having thread holes 22 and 22' and a needle like extreme end. The second longitudinal swing member 19, with the upper cross thread 30 passed through the guide piece 19", is longitudinally swung at a suitable time so as to engage the upper cross thread 30 with the needle thread 40 passed through the needle 8 on the upper surface 39a of the cloth 39 for completing overcasting stitches, as may be seen in FIGS. 7, 8 and 9. At this time, the needle point 8' of the needle 8 passes through an arcuate configuration 30" defined by the upper cross thread 30 and the guide piece 19", as best seen in FIG. 9.
The third longitudinal swing member 20 is mounted by a fulcrum pin 20' to the base plate 1 as shown in FIG. 2, and a lower cross thread guide piece 23, which will be hereinafter described, is attached to the forward end of the third longitudinal swing member 20. As may be seen in FIGS. 4, 5, 6, 7, 8, 9 and 10, the lower cross thread guide piece 23, with the lower cross thread 31 passed through a thread hole 23" provided at the extreme end 23' thereof, is given vertical swing B so as to form a loop 22" on the upper side of the upper cross thread guide piece 19". Then, the lower cross thread 31 is led under the lower surface 39b of the cloth 39 to be engaged with the needle point 8' and consequently with the bobbin thread 41 for producing overcasting stitches.
Now the lower cross thread guide piece 23 carried by the third longitudinal swing member 20 will be described with reference to FIGS. 2, 4, 5, 6, 7 and 8. The lower cross thread guide piece 23 imparts on the lower cross thread 31 the longitudinal swing C as well as the vertical swing B, raising and lowering it at a suitable time. When the lower cross thread 31 passed through the thread hole 23" is brought above the upper cross thread guide piece 19", the upper cross thread 30 can be passed below the lower cross thread 31.
For this end, the longitudinal swing member 20 has at the front end thereof bearings 25 and 25'. The lower cross thread guide piece 23 has a central support stud 24 which is pivotally received by the bearings 25 and 25', and projecting pins 26 and 26' provided on the right and left sides of the central support stud 24 in front thereof. There is provided an arcuate upright piece 28 having elongated narrow slots 27 and 27' and disposed in such a way that the projecting pins 26 and 26' extend through the slots 27 and 27' so as to move the lower cross thread guide piece 23 like a thread take-up lever and thereby to impart longitudinal swing C and vertical swing B on the extreme end 23' having the thread hole 23".
The fourth longitudinal swing member 21 is mounted by a fulcrum pin 21' to the base plate 1, and the swinging movement thereof is transmitted to a thread pulling lever 33 so as to pull or push back the lower cross thread 31 at a suitable time for smooth feed thereof conforming to the longitudinal swing C of the thread guide piece 23.
More particularly, a connecting lever 32 is connected at one end to a connecting pin 21" of the longitudinal swing member 21, and at its the other end to a connecting pin 32' to the thread pulling lever 33 which is carried at a fulcrum pin 34' by a mounting plate 34 secured to the base plate 1 by set screws 34". The lever 33 has at the extreme end thereof an upright piece 33' having a thread hole 33" for the lower cross thread 31. The swinging movement of the fourth longitudinal swing member 21 is transmitted to the upright piece 33' in the form of the transverse swing D. (As may be seen in FIGS. 1, 2 and 4, the lower cross thread 31 passes through the hole 33' between two thread holes 49' and 49" formed in the upper portion of another upright piece 49 of the mounting plate 34.) Thus, the lower cross thread 31 can be pulled or pushed back at a suitable time so as to be accurately engaged with the upper cross thread 30 at the edge 39c of the cloth 39 for completing overcasting stitches.
Turning now to FIGS. 1 through 4, reference numerals 35 and 36 designate an upper cross thread tension regulator and a lower cross thread tension regulator, respectively, mounted to a mounting base 47 which in turn is fixed to the base plate 1 by set screws 47'. Each of the thread tension regulators 35 and 36 has two thread holes associated therewith, as generally indicated by numerals 35', 35" and 36', 36". The upper cross thread 30 is held by the thread tension regulator 35 through the holes 35', 35" and led to the thread holes 22, 22', as discussed in the preceding paragraphs, while the lower cross thread 31 is held by the thread tension regulator 36 through the holes 36', 36" and led to the thread holes 49', 49".
Reference numeral 37 designates a cloth guide plate having a guide portion 37' extending over a part thereof and generally below the needle 8, to provide a spacing for guiding the cloth 39 therebetween. The guide portion 37' has a thread-truing projection 37" for maintaining the loop 22" at a constant position, as may be seen in FIGS. 5, 8 and 9.
Reference numeral 38 is a cloth presser roller fixedly connected to the fixture 3 and extending toward the needle 8 location to guide and hold the cloth 39 in cooperation with the guide portion 37' while the cloth 39 is fed by the feed dog 48 of the sewing machine.
Connected to the rear end of the base plate 1 through set screws 42' is a bobbin holder base 42 having a bobbin holder 43 on which bobbins of threads 30 and 31 are held. The bobbin holder base 42 includes a rod post 44' fixedly connected thereto, which in turn carries a thread guide rod 44 in its hole 44" through a clamp screw 45". The thread guide rod 44 has a thread guide fixture 45 connected thereto by a clamp nut 45' and extending substantially horizontally from the top thereof. As generally seen in FIGS. 1 and 3, the thread guide fixture 45 has at its bifurcated free ends a pair of substantially U-shaped thread guide portions 30' and 31' through which the threads 30 and 31 from the bobbins are passed to be led to the respective thread tension regulators 35 and 36.
Further, reference numeral 46 designates a cover for the attachment which is secured to the mounting plate 34 and the bobbin holder base 42 by screws 46'.
In operation, the edge 39c of the cloth 39 is fitted into the guide portion 37' of the cloth guide plate 37, and then led under the cloth presser roller 38. When the cloth 39 is fed by the feed dog 48 for straight stitching, the cross threads 30 and 31 engage the needle thread 40 and the bobbin thread 41 from sideways to produce overcasting stitches by four threads, while at the same time the sewing machine produces straight stitches 40' and 41', as has been discussed hereinbefore with reference to FIGS. 5 through 11.
More particularly, with reference to FIG. 5, the needle 8 is shown in its raised position to start a stitch forming. The hole 23" of the thread guide piece 23 carrying lower cross thread 31 is located above the hole 22' of the thread guide piece 19" carrying an upper cross thread 30. In FIGS. 6 and 8, the thread guide piece 23 is lowered to form a loop 22". In FIGS. 7 and 9, the thread guide pieces 19" and 23 are moved forward to extend above and below the cloth, respectively. Then the needle 8 comes down. On the upper surface of the cloth the needle thread is locked with the upper cross thread 30 while on the lower surface of the cloth the bobbin thread is locked with the lower cross thread 31. (For clarity, in FIG. 7 the paths of the upper and lower cross threads are not illustrated in great detail. Such paths are best seen in FIG. 10.). Finally, in FIG. 5, as the needle is raised to complete a proper lock stitch, all the four threads are tightened, thereby forming an overcasting stitch.
The attachment described above can be attached to ordinary sewing machines, domestic or industrial, to simply produce overcasting stitches which has been heretofore impossible of formation by those conventional sewing machines, and furthermore, in case a fancy yarn is applied as the upper cross thread 30, fancy overcasting stitches can be produced. Thus, the inventive attachment has unique, superb effects and advantages.
Referring now to FIG. 13, there is shown a modified form of the upper cross thread guide piece 119" and the lower cross thread guide piece 123. As discussed in the preceding paragraphs, the upper cross thread 30 passes through the holes 122 and 122' of the guide piece 119" and engages the needle thread and the lower cross thread 31 engages the bobbin thread to produce overcasting stitches. Each of the modified guide pieces 119" and 123 has a crooked end, as generally indicated by numerals 61 and 62 in FIG. 13, to provide a larger arcuate or bow-shaped configuration through which the needle point 8' passes. Thus, the modified ends of the guide pieces 119" and 123 ensures the positive hooking engagement of the needle 8 with the cross threads 30 and 31.
Further, the thread guide portions 30' and 31' of the thread guide fixture 45 may be rounded to form a spiral configuration, in which case each of the cross threads 30 and 31 may pass through the spiral in a stable and steady condition so as to ensure uniform overcasting performance. Such an modified configuration 30'A or 31'A is illustrated in FIG. 14.
Attention is now directed to FIGS. 15 and 16 which illustrate the second embodiment according to the present invention similar to that shown in FIG. 2. In this embodiment, the deformed elongated slot 14, the longitudinal swing member 18 and the thread-truing projection 37" are omitted. In FIG. 15, a thread-truing guide piece 64 is connected to a connecting lever 132. Like parts are given like reference numbers.
The thread-truing guide piece 64 is of a generally sickle-like configuration, one end 64' of which being located adjacent the needle point 8', as best illustrated in FIG. 15, and the other end 66 being slidably carried in a hole 67 of the connecting lever 132. The thread-truing guide piece 64 is pivoted at its mid portion to the base plate 1 by a fulcrum pin 65. With this arrangement, the swinging movement of the connecting lever 132 imparts transverse swing movement to the end 64' of the guide piece 64 so as to maintain the mutual intersecting engagement of threads 30 and 31 at a uniform position 63. Thus, it is to be noted that the uniform engagement position 63, where the upper thread 30 intersects the lower thread 31, may provide uniform trim overcasting stitches.
Further, in both the first and second embodiments, the cloth guide plate 37 may be fabricated with a pair of cutters 68 and 69, in which case the first cutter 68 is secured to a part of the cloth guide plate 37 and the second cutter 69 is swingable in tightly contacting engagement with the first cutter 68 to thereby cut and trim the edge 39c of the cloth 39, while at the same time the overcasting is being performed.
While the invention has been described with reference to preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the scope of the present invention which is defined by the appended claims.
|
The present invention relates to an attachment for a sewing machine, and more particularly to an overcasting attachment for use with a lockstitch sewing machine which is prepared for straight stitching, wherein needle-like thread guide pieces are provided for passing an additionally prepared thread or threads from sideways around the needle point at a suitable time, making use of the vertical reciprocating movement of the needle, so as to engage the thread or threads with the sewing machine threads for straight stitching.
| 3
|
GRANT INFORMATION
This invention was made with Government support under Grant No. 5 R 01 CA23263, awarded by the National Institutes of Health. The Government has certain rights in this invention.
CROSS-REFERENCE TO RELATED APPLICATION
This is a division of application Ser. No. 623,348, filed Dec. 7, 1990, now pending, which is a continuation-in-part of U.S. patent application Ser. No. 495,341, filed Mar. 19, 1990 now abandoned, which is a divisional of U.S. patent application Ser. No. 278,652 (filed Dec. 5, 1988) (U.S. Pat. No. 4,931,559) which is a continuation-in-part of U.S. patent application Ser. No. 146,252, filed Jan. 20, 1988 (U.S. Pat. No. 4,916,224).
FIELD OF THE INVENTION
The present invention relates to a therapeutic method employing dideoxycarbocyclic nucleosides which exhibit antiviral activity.
BACKGROUND OF THE INVENTION
Despite intensive effort to discover drugs that may be of value in the systemic treatment of human immuno-deficiency virus (HIV) infections, such infections have been singularly resistant to chemotherapy. The intracellular and intimate relation to nuclear metabolism of virus reproduction makes it difficult to destroy a virus without irreparable damage to the host cell.
The discovery of the antiviral activity of vidarabine (9-β-D-arabinofuranosyladenine monohydrate) has led to the preparation of a large number of synthetic nucleosides. To date, only one synthetic nucleoside, 3'-azido-3'-deoxythymidine has been approved for treating certain AIDS patients, but it is a palliative, not a cure. ##STR2##
Although AZT is specifically active against retroviruses, its use has led to side effects, including anemia, headache, confusion, anxiety, nausea and insomnia. The nucleoside analog, 2',3'-dideoxycytidine (DDC), exhibits an in vitro TI 50 of ca. 300 against HIV and may exhibit fewer side effects than AZT, but may also be eliminated more rapidly from the body. ##STR3## The synthesis of adenine ("6-amino-purine") nucleoside analogs in which the pentose sugar has been replaced with tris(hydroxy)-substituted cyclopentyl residues has yielded compounds with substantial cytotoxic and antiviral activity. For example, the carbocyclic analog of vidarabine, cyclaridine, is highly active against HSV-2, but exhibits a low therapeutic index (TI 50 =10) against HIV in vitro. Likewise, the carbocyclic analog of AZT is inactive against HIV. Therefore, it is clear that the structure-activity relationships between the variously substituted carbocyclic nucleosides which have been prepared and tested remain ill-defined.
Thus, a substantial need exists for chemotherapeutic agents effective to protect mammalian cells against infection by viruses such as HSV-2, HIV, varicella-zoster, vaccinia, human cytomegalovirus (HCMV) and the like.
SUMMARY OF THE INVENTION
The present invention is directed to hydroxymethylcyclopentenyl-substituted purines and 8-aza-purines of the formula (I): ##STR4## wherein Z is H, OR' or N(R) 2 , Y is CH or N, and X is selected from the group consisting of H, N(R) 2 , SR, OR' and halogen, wherein R is H, lower(C 1 -C 4 )alkyl, aryl or mixtures thereof, wherein R' is H, (C 1 -C 4 )alkyl, aryl, CHO, (C 1 -C 16 )alkanoyl, or O=P(OH) 2 , and the pharmaceutically acceptable salts thereof. Preferably, X is Cl, OR', most preferably OH; or N(R) 2 , Y is CH, R is phenyl or H, and R' is H or acetyl. As used herein, the term "aryl" includes substituted and unsubstituted aralkyl (preferably ar(C 1 -C 4 )alkyl) moieties. Preferred aryl moieties include phenyl, tolyl, xylyl, anisyl, or phen(C 1 -C 4 )alkyl, e.g., benzyl or phenethyl. Certain of these compounds are effective antiviral and/or cytotoxic agents or are intermediates useful for the preparation thereof.
A given compound within the scope of the formula has two optically active centers, indicated by the symbol (*) in formula I, either of which can exhibit R, S or RS stereochemistry. Therefore, single resolved, optically active enantiomers and diasteriomers of the present compounds are preferred embodiments of the present invention, although partially resolved and racemic (±) mixtures are also within the scope of the invention. The four stereoisomers of the compound of formula I are depicted below: ##STR5## wherein X, Y, Z and R' are defined hereinabove. The stereoconfigurations are given using the cyclopent-2-en-4-yl-1-carbinol nomenclature.
Certain of the compounds of formula I may exist as a mixture of tautomeric forms and all such tautomers are included within the scope of the invention.
A preferred compound of the invention is the optically active enantiomer of the formula II: ##STR6## wherein X, Y, Z and R' defined above and the stereochemistry at the optically active centers is as depicted. A wedged line indicates a bond extending above the plane of the cyclopentenyl ring, while a dashed line indicates a bond extending below the plane of the cyclopentenyl ring.
Although generally compounds of formula I are not active against HSV-1, it is expected that some of them will exhibit specific antiviral activity against other viruses such as hepatitis, HSV-2, EBV, RSV, PRV, HCMV and/or HIV, as well as against other retroviruses, such as those believed to cause T-cell leukemia. Specifically, the racemic compound of formula I, wherein X is OH, Z is NH 2 , Y is CH and R' is H (14a), strongly inhibits HIV infectivity in vitro. The TI 50 of this compound varied with the infected cell line which was used to assay for anti-HIV activity, but generally fell between 200-400, and was determined to be as high as 667 in one assay. The acetate ester (R'=Ac) of 14a was also active against HIV, giving 28% inhibition at 6 μg/ml. Compound 14a is also active against HSV-1.
The fully resolved compound of formula II, wherein X is OH, Z is NH 2 , Y is CH and R' is H ((-)14a) is also highly active against HIV [(1'R,4'S)-2-amino-1,9-dihydro-9-[4'-hydroxymethyl-2'-cyclopenten-1-yl[-6H-purin-one, or (1S,4R)-4-(2-amino-6-hydroxy-9H-purin-9-yl)-2-cyclopentenylcarbinol]. Compounds of formula I wherein X is Cl or N(R) 2 , Y is CH, Z is NH 2 and R' is H (13a and 15a, respectively) are also active against HIV, as are compounds wherein X is Cl, NHz or SH, Y is CH, Z is H and R' is H (7a, 9a and 10a, respectively). Compounds 7a, 9a and 10a, as well as compounds of the formula I wherein Y═N, Z═NH 2 , X═Cl, NH 2 or OH and R' is H (16a, 18a and 17a), are cytotoxic to cultured P-388 leukemia cells. It is believed that the antiviral activity is due to an inhibitory effect on the ability of viruses to infect normal mammalian cells. The present invention is also directed to the intermediate compound of the formula (III): ##STR7## wherein Z is H or NH 2 , Z' is H or NH 2 , and X is halogen, preferably Cl, which is useful for the preparation of the purines of the invention. Preferably, Z is NH 2 , and Z' is H or both Z and Z' are NH 2 . However, the compounds where Z═Cl, Z═NH 2 and Z'═H or NH 2 are not active against HIV.
The (3-hydroxymethylcyclopentenyl)pyrimidine analog, 20a, is also within the scope of the present invention. Its synthesis from cyclopentene 2a is outlined in Scheme I, below. ##STR8##
In compounds 19a and 20a, R can be CH 3 or H. Thus, it is expected that certain of the compounds of the present invention will be useful against viral infections or virus-associated tumors, and the method of their use to inhibit viral infectivity or tumor growth in vitro or in vivo is also within the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram summarizing the synthesis of the purines of the present invention.
FIG. 2 is a graphic depiction of cells exposed to 14a/control cells (%) plotted vs. concentration of 14a for both uninfected cells and cells infected with HIV.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 outlines the synthesis of preferred compounds of the invention from starting material 1a. The structural formulas and some of the properties of compounds 7a-18a are summarized on Table I, below.
TABLE I______________________________________A. 2', 3'-Dideoxy-6-Substituted-Purines of Formula I, Z═H.CompoundNo. X Y M.P. (°C.) Rf Yield (%)______________________________________ 7a Cl CH 108-110 .sup. 0.35.sup.a 82 8a OH CH 248-250 (dec) .sup. 0.24.sup.b 45 9a NH.sub.2 CH 198-200 .sup. 0.33.sup.b 8110a SH CH 263-265 (dec) .sup. 0.44.sup.b 7311a OH N 180-182 .sup. 0.38.sup.b 4912a NH.sub.2 N 220-222 (dec) .sup. 0.45.sup.b 69______________________________________B. 2', 3'-Dideoxy-2,6-Disubstituted-Purines of Formula I,Z═NH.sub.2.CompoundNo. X Y M.P. (°C.) Rf.sup.b Yield (%)______________________________________13a Cl CH 145-147 0.64 8014a OH CH 254-256 (dec) 0.27 6115a NH.sub.2 CH 152-155 0.41 8016a Cl N 153-155 (dec) 0.69 8117a OH N 223-225 (dec) 0.40 8918a NH.sub.2 N 240-242 (dec) 0.52 83______________________________________ .sup.a CHCl.sub.3 :MeOH, 10:1. .sup.b CHCl.sub.3 :MeOH, 5:1.
These compounds are candidates for clinical trials in human patients infected with HIV and/or afflicted with AIDS or AIDS-related complex (ARC).
The synthesis of the hydroxymethylcyclopentenyl compounds of formula 7a-18a, from the versatile precursor, 1α-acetylamino-4α-acetoxymethylcyclopent-2-ene (1a) was accomplished as outlined in FIG. 1. Compound 1a was prepared as described in U.S. Pat. No. 4,138,562, the disclosure of which is incorporated by reference herein. Compound 2a was prepared from compound la by hydrolysis in the presence of a mild base, such as an alkaline earth metal hydroxide. To afford the pyrimidine compound 3a, Z═H, compound 2a was reacted with an excess of 5-amino-4,6-dichloropyrimidine in the presence of an amine base, such as a trialkylamine, in an alcoholic solvent. Also, 2-amino-4,6-dichloropyrimidine was reacted with compound 2a to yield compound 4a.
Para-chloroaniline was diazotized with acidic sodium nitrite and reacted with compound 4a to yield the chlorophenylazo intermediate 5a. Reduction of the azo intermediate 5a to yield 6a was accomplished with zinc and acetic acid. See Shealy and Clayton, J. Pharm. Sci., 62, 1433 (1973).
The 5-amino-6-chloro-4-pyrimidinyl intermediate 3a was converted to the 9-substituted-6-chloropurine 7a (Z═H) by ring closure with triethylorthoformate and subsequent mild acid hydrolysis to remove ethoxymethylidenes and formates formed during the reaction. In like manner, the 2,5-diamino-6-chloro-4-pyrimidinyl intermediate 6a was ring-closed to the corresponding 2-amino-6-chloro-9H-purin-9-yl compound 13a.
The 6-chloropurines 7a and 13a were converted to the corresponding 6-hydroxy purines 8a and 14a, respectively, with aqueous base, i.e., by refluxing them with an alkali metal hydroxide such as NaOH. Chloro compounds 7a, 13a and 16a were converted to the corresponding amino compounds 9a, 15a and 18a by reaction with liquid ammonia under pressure.
Mono- or di-substituted 6-amino compounds of formula I, wherein X is NR 2 and R═R═(lower)alkyl, phenyl or mixtures thereof with H, can be prepared by conventional methods for the conversion of halides to secondary or tertiary amines. For example, see I. T. Harrison et al., Compendium of Organic Synthetic Methods, Wiley-Interscience, NY (1971) at pages 250-252. The 6-chloro substituent in compounds 7a, 13a and 16a can be replaced with other halogen atoms by the use of various p-(halo)benzene diazonium chlorides in the conversion of 4a to 5a, or by conventional methods of halide-halide exchange.
These conversions are extensively described in the context of purine nucleoside synthesis in Nucleoside Analogs-Chemistry, Biology and Medical Applications, R. T. Walker et al., eds., Plenum Press, NY (1979) at pages 193-223, the disclosure of which is incorporated by reference herein.
Treatment of 7a with thiourea in refluxing alcohol, followed by alkaline hydrolysis afforded thiol 10a. See L. F. Fieser et al., Reagents for Organic Synthesis, John Wiley and Sons, Inc., NY (1967) at pages 1165-1167 and U.S. Pat. No. 4,383,114, the disclosures of which are incorporated by reference herein. Phenyl or alkylthio-derivatives can be prepared from the corresponding thiols by the procedure of U.S. Pat. No. 4,383,114 (Example 6).
Ring closure of 3a with acidic aqueous sodium nitrate followed by neutralization with aqueous base directly afforded the corresponding 7-hydroxy-3H-1,2,3-triazolo[4,5d]pyrimidin-3-yl compound 11a. Ring closure of 6a afforded the corresponding 5-amino-7-chloro-3H-1,2,3-triazo[4,5d]pyrimidin-3-yl compound 16a, which was hydrolyzed to the corresponding 7-hydroxy compound 17a with aqueous NaOH. Compound 3a was converted to the corresponding 7-amino compounds 12a by reaction with acidic sodium nitrite, followed by reaction of the crude product with liquid ammonia. Compounds of formula I, wherein Z is OH, X is NH 2 or OH, and Y is CH can be prepared from compounds 14a, 15a by deamination of the 2-amino group with nitrous acid, employing the procedure used by Davoll to convert 2-aminoadenosine to isoguanosine. See J. Davoll, J. Amer. Chem. Soc., 73, 3174 (1951), the disclosure of which is incorporated by reference herein.
Compounds of formula I, wherein X is H, Z is NH 2 and Y is CH can be prepared from compounds 7a or 13a by dehalogenation with zinc/water [J. R. Marshall et al., J. Chem. Soc., 1004 (1951)] or by photolysis in dry nitrogen-purged tetrahydrofuran containing 10% triethylamine in a Rayonet photochemical reactor (2537 Å) by the method of V. Nair et al., J. Org. Chem., 52, 1344 (1987).
Phosphate or alkanoyl esters of compounds of formula I can be prepared as disclosed in R. Vince (U.S. Pat. No. 4,383,114), the disclosure of which is incorporated by reference herein, employing selective protection of, e.g., the hydroxymethyl or 6-hydroxyl groups, as necessary. Pharmaceutically-acceptable acid salts of compounds 7a-18a can be prepared as described in U.S. Pat. No. 4,383,114, the disclosure of which is incorporated by reference herein.
The invention will be further described by reference to the following detailed examples wherein elemental analyses were performed by M-H-W Laboratories, Phoenix, AZ. Melting points were determined on a Mel-Temp apparatus and are corrected. Nuclear magnetic resonance spectra were obtained on Jeol FX 90QFT or Nicollet NT300 spectrometers and were recorded in DMSO-D 6 . Chemical shifts are expressed ppm downfield from Me 4 Si. IR spectra were determined as KBr pellets with a Nicollet 50XC FT-IR spectrometer, and UV spectra were determined on a Beckmann DU-8 spectrophotometer. Mass spectra were obtained with an AEI Scientific Apparatus Limited MS-30 mass spectrometer. Thin layer chromatography (TLC) was performed on 0.25 mm layers of Merck silica gel 60F-254 and column chromatography on Merck 60 silica gel (230-400 mesh). All chemicals and solvents are reagent grade unless otherwise specified.
EXAMPLE 1
(±)-(1α,4α)-4-[(5-Amino-6-chloro-4-pyrimidinyl)-amino]-2-cyclopentenylcarbinol (3a)
A mixture of 1a (3.0 g, 15 mmol) and aqueous barium hydroxide (0.5N, 300 ml) was refluxed overnight. After cooling, it was neutralized with dry ice. The precipitate was filtered out, and the aqueous solution was concentrated to dryness. The residue was extracted with absolute ethanol and concentrated again to yield 2a as a colorless syrup 1.6 g (14 mmol).
To this syrup, 5-amino-4,6-dichloropyrimidine (4.59 g, 28 mmol), triethylamine (4.2 g, 42 mmol), and n-butanol (50 ml) were added and the mixture was refluxed for 24 hr. The volatile solvents were removed, the residue was absorbed on silica gel (7 g), packed in a flash column (4.0×12 cm) and eluted with CHCl 3 -MeOH (20:1) to yield 2.69 g (74%) of compound 3a; mp 130°-132° C. An analytical sample was obtained by recrystalization from ethyl acetate (EtOAc), mp 134°-135° C., MS (30 ev, 200° C.); m/e 240 and 242 (M + and M + +2), 209 (M + -31), 144 (B + ); IR: 3600-2600 (OH), 1620,1580 (C═C, C═N); Anal. (C 10 H 13 ClN 4 O) C,H,N.
EXAMPLE 2
(±)-(1α,4α)-4-[ (2-Amino-6-chloro-4-pyrimidinyl)-amino]-2-cyclopentenylcarbinol (4a)
To 14 mmol of crude 2a, 2-amino-4,6-dichloropyrimidine (3.74 g, 22.8 mmol), triethylamine (15 ml) and n-butanol (75 ml) were added and the mixture was refluxed for 48 hr. The volatile solvents were removed, residue was treated with methanol to separate the undissolved byproduct (the double pyrimidine nucleoside). The methanol solution was absorbed on silica gel (8 g) packed into a column (4.0 ×14 cm) and eluted with CHCl 3 -MeOH (40:1) to yield 1.52 g (42%) of crude 4a. The product was recrystalized from ethyl acetate to yield 4a; mp 132°-134° C., MS (30 ev, 200° C.); m/e 240 and 242 (M + and M + +2), 209 (M + -31), 144 (B + ); IR: 3600-3000 (NH 2 , OH), 1620,1580 (C═C, C═N); Anal. (C 10 H 13 ClN 4 O) C,H,N.
EXAMPLE 3
(±)-(1α,4α)-4-{[2-Amino-6-chloro-5-(4-chlorophenyl)-azo]-4-pyrimidinyl]-amino }-2-cyclopentenylcarbinol (5a)
A cold diazonium salt solution was prepared from p-chloroaniline (1.47 g, 11.5 mmol) in 3N HCl (25 ml) and sodium nitrite (870 mg, 12.5 mmol) in water (10 ml). This solution was added to a mixture of 4a (2.40 g, 10 mmol), acetic acid (50 ml), water (50 ml) and sodium acetate trihydrate (20 g). The reaction mixture was stirred overnight at room temperature. The yellow precipitate was filtered and washed with cold water until neutral, then it was air-dried in the fumehood to yield 3.60 g (94%), of 5a, mp 229° C. (dec). The analytical sample was obtained from acetone-methanol (1:2), mp 241°-243° C. (dec). MS (30 ev, 260° C.): m/e 378 and 380 (M + and M + +2), 282 (B + ); IR: 3600-3000 (NH 2 , OH), 1620,1580 (C═C, C═ N); Anal. (C 16 H 16 Cl 2 N 6 O) C,H,N.
EXAMPLE 4
(±)-(1α,4α)-4-(2,5-Diamino-6-chloro-4-pyrimidinylamino]-2 cyclopentenYlcarbinol (6a).
A mixture of 5a (379 mg, 1 mmol), zinc dust (0.65 g, 10 mmol), acetic acid (0.32 ml), water (15 ml) and ethanol (15 ml) was refluxed under nitrogen for 3 hr. The zinc was removed and the solvents were evaporated. The residue was absorbed on silica gel (2 g), packed into a column (2.0×18 cm), and eluted with CHCl 3 --MeOH (15:1). A pink syrup was obtained. Further purification from methanol-ether yielded 6a as pink crystals, 170 mg (66%), mp 168°-170° C., MS (30 ev, 220° C.); m/e 255 and 257 (M + and M + +2), 224 (M + -31), 159 (B + ); IR: 3600-3000 (NH 2 , OH), 1620,1580 (C═C, C═N); Anal. (C 10 H 14 ClN 5 O) C,H,N.
EXAMPLE 5
(±)-(1α,4α)-4-(6-chloro-9H-purin-9-yl)-2-cyclopentenylcarbinol (7a)
A mixture of 3a (1.30 g, 5.4 mmol), triethyl orthoformate (30 ml) and hydrochloric acid (12N, 0.50 ml) was stirred overnight at room temperature. The solvent was evaporated at 35° C. in vacuo. To the residue was added aqueous hydrochloric acid (0.5N, 30 ml) and the mixture was stirred for 1 hr. The mixture was neutralized to pH 7-8 with 1N sodium hydroxide and absorbed onto silica gel (8 g), packed in a column (4.0×8 cm), and eluted with CHCl 3 --MeOH (20:1) to yield white crystals of 7a, 1.12 g (82%). The crude product was recrystalized from ethyl acetate to yield 7a, mp 108°-110° C., MS (30 ev, 200° C.); m/e 250 and 252 (M + and M + +2), 219 (M + -31), 154 (B + ); IR: 3600-2800 (OH), 1600 (C═C, C═N); Anal. (C 11 H 11 ClN 4 O) C,H,N.
EXAMPLE 6
(±)-(1α,4α)-4-(6-Hydroxy-9H-purin-9-yl)-2-cyclopentenylcarbinol (8a)
A mixture of 7a (251 mg, 1 mmol) and aqueous sodium hydroxide (0.2N, 10 ml) was refluxed for 3 hr. After cooling, the reaction mixture was adjusted to pH 5-6 with acetic acid. The reaction mixture was absorbed on silica gel (2 g) packed in a column (2.0×11 cm) and eluted with CHCl 3 -MeOH (10:1) to yield 105 mg (45%) of 8a. The crude white product was recrystalized from water-methanol (3:1) to yield 8a, mp 248°-250° C. (dec), MS (30 ev, 300° C.); m/e 232 (M + ), 214 (M + -18), 136 (B + ); IR; 3600-2600 (OH), 1680,1600 (C═O, C═C, C═N); Anal. (C 11 H 12 N 4 O 2 ) C,H,N.
EXAMPLE 7
(±)-(1α,4α-4-(6-Amino-9H-purin-9-yl)-2-cyclopentenylcarbinol (9a)
Liquid ammonia was passed into a bomb containing a solution of 7a (250 mg, 1 mmol) in methanol (5 ml) at -80° C. The bomb was sealed and heated at 60° C. for 24 hr. Ammonia and methanol were evaporated and the residue was recrystalized from water to yield off-white crystals of 9a, 187 mg (81%), mp 198°-200° C., MS (30 ev, 210° C.): m/e 231 (M + ), 213 (M + -18), 135 (B + ); IR: 3600-2600 (NH 2 , OH), 1700,1600 (C═C, C═N); Anal. (C 11 H 13 N 5 O) C,H,N.
EXAMPLE 8
(±)-(1α,4α)-4-(6-Mercapto-9H-purin-9-yl)-2-cyclopentenylcarbinol (10a)
A mixture of 7a (125 mg, 0.5 mmol), thiourea (40 mg, 0.64 mmol) and n-propanol (5 ml was refluxed for 2 hr. After cooling, the precipitate was isolated by filtration, washed with n-propanol, and dissolved in sodium hydroxide (1N, 5 ml). The solution was adjusted to pH 5 with acetic acid. The crude 10a (90 mg, 73%) was isolated again, mp 260°-262° C. (dec) and was recrystalized from N,N-dimethylformamide, to yield 10a, mp 263°-265° C. (dec) MS (30 ev, 290° C.): m/e 248 (M + ), 230 (M + -18), 152 (B + ); IR: 3600-3200 (OH), 3100,2400 (SH), 1600 (C═C, C═N); Anal. (C 11 H 12 N 4 OS) C,H,N.
EXAMPLE 9
(±)-(1α,4α)-4-(7-Hydroxy-3H-1,2,3-triazolo[4,5-d]pyrimidin-3-yl)- 2-cyclopentenyl carbinol (11a).
To a cold solution of 3a (361 mg, 1.5 mmol) in hydrochloric acid (1N, 30 ml) was added sodium nitrite solution (120 mg, 1.7 mmol) in 3 ml of water. The reaction was monitored by starch-potassium iodide paper. The mixture concentrated at 40° C. to a volume of 2 ml and adjusted to pH 7 with aqueous sodium hydroxide. The mixture was absorbed on silica gel (2 g), packed in a column (2.0×13 cm) and eluted with CHCl 3 -MeOH (10:1). The crude 11a was recrystallized from water-methanol (3:1) to yield white crystals of 11a, 173 mg (49%) mp 180°-182° C. MS (30 ev, 230° C.): m/e 233 (M + ), 203 (M + -30), 137 (B + ); IR: 3600-2600 (OH), 1740,1600 (C═O, C═C, C═N); Anal. (C 10 H 11 N 5 O 2 ) C,H,N.
EXAMPLE 10
(±)-1α,4α)-4-(7-Amino-3H-1,2,3-triazolo[4,5d]pyrimidin-3-yl)-2-cyclopentenyl carbinol (12a)
Sodium nitrite solution (828 mg, 12 mmol) in water (10 ml) was added dropwise to a cold solution of 3a (2.43 g, 10.1 mmol) in hydrochloric acid (0.5N, 40 ml). The reaction mixture was stirred at room temperature for 1 hr, then concentrated to a syrup. The syrup was dissolved in ethanol and transferred into a stainless steel bomb. Liquid ammonia was passed in, the bomb was sealed, and the reaction mixture was stirred at room temperature overnight. Ammonia was evaporated and the residue was chromatographed on silica gel (150 g) eluting with CH 2 Cl 2 --MeOH (10:1) to yield white crystals of 12a, 1.62 g (69%), mp 220°-222° C. (dec). MS (30 ev, 220° C.): m/e 232 (M + ), 202 (M + -30), 136 (B + ); IR: 3600-2800 (NH 2 , OH), 1700,1600 (C═C, C═N); Anal. (C 10 H 12 N 6 O) C,H,N.
EXAMPLE 11
(±)-(1α,4α)-4-(2-Amino-6-chloro-9H-purin-9-yl)-2-cyclopentenyl carbinol (13a)
A mixture of 6a (1.41 g, 5.5 mmol) triethyl orthoformate (30 ml) and hydrochloric acid (12N, 1.40 ml) was stirred overnight. The suspension was dried in vacuo. Diluted hydrochloric acid (0.5N, 40 ml) was added and the mixture was reacted at room temperature for 1 hr. The mixture was neutralized to pH 8 with 1N sodium hydroxide and absorbed on silica gel (7.5 g) packed in a column (4.0×10 cm) and eluted by CHCl 3 -MeOH (20:1) to yield off-white crystals of 13a, 1.18 g (80%). The crude product was recrystalized from ethanol to yield 13a, mp 145°-147° C. MS (30 ev, 220° C.): m/e 265 and 267 (M + and M + +2), 235 (M + -30), 169 (B + ); IR: 3600-2600 (NH 2 , OH), 1620,1580 (C═C, C═N); Anal. (C 11 H 12 N 5 OCl a 3/4 H 2 O) C,H,N.
EXAMPLE 12
(±)-(1α,4α)-4-(2-Amino-6-hydroxy-9H-purin-9-yl)- 2-cyclopentenyl carbinol (14a)
A mixture of 13a (266 mg, 1 mmol) and aqueous sodium hydroxide (0.33N) was refluxed for 5 hr., absorbed onto silica gel (2 g) packed in a column (2.0×7.5 cm) and eluted with CHCl 3 --MeOH (5:1). The crude product was recrystalized from methanol-water (1:4) to yield white crystals of 14a, 152 mg (61%), mp 254°-256° C. (dec). MS (30 ev, 200° C.): m/e 247 (M + ), 217 (M + -30), 151 (B + ); IR: 3600-2600 (NH 2 , OH), 1700,1600 (C═O, C═C, C═N); Anal. (C 11 H 13 N 5 O 2 a 3/4 H 2 O) C,H,N.
EXAMPLE 13
(±)-(1α,4α)-4-(2,6-Diamino-9H-purin-9-yl)-2-cyclopentenylcarbinol (15a)
Liquid ammonia was passed into a solution of 13a (265 mg, 1 mmol) in methanol (10 ml) at -80° C. in a bomb. The bomb was sealed and heated at 75° C. for 48 hr. Ammonia and methanol were evaporated. The residue was absorbed on silica gel (2 g), packed in a column (2.0×10 cm) and eluted with CHCl 3 -MeOH (15:1). The crude product was recrystalized from ethanol to yield 196 mg (80%) of 15a, mp 152°-155° C. MS (30 ev, 200° C.): m/e 246 (M + ), 229 (M + -17), 216 (M + -30), 150 (B + ); IR: 3600-3000 (NH 2 , OH), 1700,1650,-1600 (C═O, C═C, C═N); Anal. (C 11 H 14 N 6 O) C,H,N.
EXAMPLE 14
(±)-(1α,4α)-4-(5-Amino-7-chloro-3H-1,2,3-triazolo[4,5d]pyrimidin-3-yl) -2-cyclopentenyl carbinol (16a)
To a cold solution of 6a (225 mg, 1 mmol) in acetic acid (1.5 ml) and water (2.5 ml) was added sodium nitrite (83 mg, 1.2 mmol) in water (2 ml). The reaction was monitored by starch-potassium iodide paper. After stirring for 1 hr. at 0° C., the precipitate was filtered and washed with cold water, then dried over phosphorus pentoxide in vacuo to yield 16a as off-white crystals, 218 mg (81%). The crude 16a was recrystalized from methanol, mp 153°-155° C. (dec). MS (30 ev, 220° C.): m/e 266 and 268 (M + and M + +2), 236 (M + -30), 170 (B + ); IR: 3600-3000 (NH 2 , OH), 1650,1600 (C═C, C═N); Anal. (C 10 H 11 ClN 6 O) C,H,N.
EXAMPLE 15
(±)-(1α,4α)-4 -(5-Amino-7-hydroxy-3H-1,2,3-triazolo[4,5-d]pyrimidin-3-yl) -2-cyclopentenyl carbinol (17a)
A mixture of 16a (218 mg, 0.8 mmol) and aqueous sodium hydroxide (0.25N, 10 ml) was refluxed for 3 hr, then was adjusted to pH 3 with 6 N hydrochloric acid. The gelatinious precipitate was filtered and washed with cold water. It was dried over phosphorous pentoxide in vacuo to yield 17a as an off-white solid, 181 mg (90%) mp 222°-224° C. (dec) After recrystalization from water, the mp was 223°-225° C. (dec). MS (20 ev, 300° C.): m/e 248 (M + ), 217 (M + -31), 152 (B + ); IR: 3600-3000 (NH 2 , OH), 1750,1600 (C═C, C═N); Anal. (C 10 H 12 N 6 O 2 .1/2 H 2 O) C,H,N.
EXAMPLE 16
(±)-(1α,4α)-4-(5,7-Diamino-3H-1,2,3-triazolo[4,5-d]pyrimidin-3-yl)-2-cyclopentenyl carbinol (18a)
Compound 16a (267 mg, 1 mmol) was processed as described in Example 13, employing a reaction time of 60° C. for 20 hr. The residual mixture was absorbed on silica gel (2 g), packed in a column (2.0×10 cm) and eluted by CHCl 3 -MeOH (15:1) to yield 18a as white crystals, 204 mg (83%). The crude product was recrystalized from ethanol-water (2:1), to yield 18a of mp 240°-242° C. (dec). MS (30 ev, 240° C.): m/e 247 (M + ), 229 (M + -18), 217 (M+-30), 151 (B + ); IR: 3600-3100 (NH 2 , OH), 1700,1650,1600 (C═O, C═C, C═N); Anal. (C 10 H 13 N 7 O. H 2 O) C,H,N.
EXAMPLE 17
(±)-(1α,4α)-4-(3-Methoxy-2-methylacryloylureido)-2-cyclopentenyl carbinol (19a)
Isocyanate reagent was prepared from 3-methoxy-2-methylacryloyl chloride (1.00 g, bp 65°-66° C./2.5 mm) in anhydrous benzene (10 ml) and freshly dried silver cyanate (2.6 g, 17 mmol, dried at 110° C., 2 hrs) by refluxing for 0.5 hr. The supernatant was added dropwise into a solution of 2a (from 1a, 0.8 g, 4 mmol) in N,N-dimethylformamide (10 ml) at -15° C. and the mixture was stirred for 1 hr, then stored at 4° C. overnight. The solvent was evaporated and the residue was absorbed on silica gel (3 g), packed in a column (2.0×16 cm) and eluted with CHCl 3 --MeOH (20:1) to yield white crystals of 19a, 605 mg, (60%), mp 147°-149° C. MS (30 ev, 200° C.): m/e 254 (M + ), 239 (M + -15), 223 (M + -31), 158 (B + ); IR: 3600-2800 (NH 2 , OH), 1700,1650,1600 (C═O, C═C); Anal. (C 12 H 18 N 2 O 4 ) C,H,N.
EXAMPLE 18
(±)-(1α,4α)-4-5-Methyl-2,4-(1H,3H)-pyrimidinedion-3-yl]-2-cyclopentenyl carbinol (20a)
A mixture of 19a (381 mg, 1.5 mmol), p-toluenesulfonic acid monohydrate (20 mg) and anhydrous N,N-dimethylformamide (2 ml) was stirred at 115° C. for 3 hr. The solvent was evaporated, the residue was absorbed on silica gel (3 g), packed in a column (2.0×14 cm) and eluted with CHCl 3 --MeOH (20:1) to yield 20a as off-white crystals, 206 mg (62%) The product was recrystalized from absolute ethanol to yield 20a, mp 213°-215° C. MS (30 ev, 250° C.): m/e 222 (M + ), 204 (M + -18), 191 (M + -31), 126 (B + ); IR: 3600-3300 l (OH), 1700,1600 (C═O, C═C); Anal. (C 11 H 14 N 2 O 3 ) C,H,N.
EXAMPLE 19
Esterification of Compound 14a
(1α,4α)-4-(2-Amino- 6-hydroxy-9H-purin-9-yl)-2-cyclopentenyl Acetoxycarbinol
To a suspension of 14a (130 mg, 0.50 mmol) and 4-dimethylaminopyridine (5 mg, 0.04 mmol) in a mixture of acetonitrile (6 ml) and triethylamine (0.09 ml, 0.66 mmol) was added acetic anhydride (0.06 ml, 0.6 mmole). The mixture was stirred at room temperature for 3 hr. Methanol (1 ml) was added to quench the reaction. The solution was concentrated and absorbed on silica gel (1.5 g), packed on a column (2.0×12 cm), and eluted with CHCl 3 --MeOH (20:1). The product fractions were collected and concentrated to yield a white solid. The solid product was washed with MeOH--AcOEt to yield 123 mg of the purified acetoxycarbinol (85%). Further purification from methanol afforded needle-like crystals, mp 237°-239° C.; Anal. (C 13 H 15 N 5 O 3 ) C,H,N.
EXAMPLE 20
(1S,4R)-4-(2-Amino-6-hydroxy-9H-Purin-9-yl)-2-cyclopentenyl Carbinol ((-)14a).
The diamino analog, 15a, (100 mg) was dissolved in 3 ml of 0.05M K 2 PO 4 buffer (pH 7.4) at 50° C. The solution was cooled at 25° C. and 40 units of adenosine deaminase (Sigma, Type VI, calf intestinal mucosa) was added. After three days of incubation at room temperature, a precipitate formed and was removed by filtration to yield 18.2 mg of crude product. The filtrate was concentrated to 1.5 ml and refrigerated for 2 days. Additional solid (26.8 mg) was obtained by filtration. The two solid fractions were recrystalized from water to yield the pure product, mp 269°-272° C.;[α] D 24 -62.1 (c 0.3 MeOH).
EXAMPLE 21
(1R,4S)-4-(2-Amino-6-hydroxy-9H-purin-9-yl)-2-cyclopentenyl carbinol ((+)14a).
The filtrates from the preparation of the 1S,4R isomer were combined and evaporated to dryness. The unchanged diamino starting material was separated on a silica gel flash column using 10% methanol/chloroform. The diamino compound was dissolved in 0.05M K 2 PO 4 buffer, pH 7.4 (15 ml) and 800 units of adenosine deaminase was added. The solution was incubated for 96 hr at 37° C. TLC indicated some unreacted product remained. The solution was heated in boiling water for 3 min and filtered to remove denatured protein. Another 800 units of adenosine deaminase was added and the processes were repeated. The deproteinated solution was evaporated to dryness and the product was crystalized from water to yield a white solid; mp 265°-270° C.;[α] D 24 +61.1 (c 0.3 MeOH).
EXAMPLE 22
Cytotoxicity Assay
The ED 50 cytotoxicity concentrations determined for analogs 7a, 9a, 10a, 16a, and in the P-388 mouse leukemia cell culture assay are given in Table II.
TABLE II______________________________________Inhibitory Concentrations of Carbocyclic Nucleosides for P-388Leukemia Cells in Cultures*Compound ED.sub.50, μg/ml______________________________________ 7a 12.0 9a 40.010a 3.016a 1.017a 4.5______________________________________ *Assay Technique: R. G. Almquist and R. Vince, J. Med. Chem., 16, 1396 (1973).
Therefore, all of the compounds listed on Table II are active against P-388 mouse leukemia.
EXAMPLE 23
Anti-HIV Assay
Compounds of formula I were screened for anti-HIV activity at the National Cancer Institute, Frederick Cancer Research Facility, Frederick, Maryland (FCRF). The following are the current screening mode operational procedures utilized at FCRF. The protocol consists of 3 areas, (I) preparation of infected cells and distribution to the test plates, (II) preparation of drug dilution plates and distribution to the test plates, and (III) XTT assay procedure. See D. A. Scudiero et al., "A New Simplified Tetrazolium Assay for Cell Growth and Drug Sensitivity in Culture," Cancer Res., 48, 4827 (1988).
I. Infection and Distribution of Cells to Microtiter Trays
Cells to be infected (a normal lymphoblastoid cell line which expresses CD4) are placed in 50 ml conical centrifuge tubes and treated for 1 hr with 1-2 μg/ml of polybrene at 37° C. The cells are then pelleted for 8 min. at 1200 rpm. HIV virus, diluted 1:10 in media (RMPl-1640, 10% human serum or 15% fetal calf serum (FCS), with IL-2, for ATH8 cells only, and antibiotics) is added to provided an MOI of 0.001. Medium alone is added to virus-free control cells. Assuming an infectious virus titer of 10 -4 , an MOI of 0.001 represents 8 infectious virus particles per 10,000 cells. About 500,000 cells/tube are exposed to 400 μl of the virus dilution. The resultant mixture is incubated for 1 hr at 37° C. in Air-CO 2 . The infected or uninfected cells are diluted to give 1×10 -4 (with human serum or 2×10 -4 with calf serum) cells/100 μl.
Infected or uninfected cells (100 μl) are distributed to appropriate wells of a 96 well, U-bottom, microtiter plate. Each compound dilution is tested in duplicate with infected cells. Uninfected cells are examined for drug sensitivity in a single well for each dilution of compound. Drug-free control cells, infected and uninfected, are run in triplicate. Wells B2 through G2 served as reagent controls and received medium only. The plates are incubated at 37° C. in Air-CO 2 until the drug is added.
II. Drug Dilution and Addition
Dilution plates (flat bottom 96 well, microtiter plates) are treated overnight with phosphate buffered saline (PBS) or media containing at least 1% FCS or 1% human serum (depending on the medium used in the test), beginning the day before assay. This "blocking" procedure is used to limit the adsorption of drug to the microtiter tray during the dilution process. The wells are filled completely with the blocking solution and allowed to stand at room temperature in a humidified chamber in a hood.
The dilution process is begun by first diluting the test compound 1:20. Blocked, dilution plates are prepared by flicking out the blocking solution and blotting dry on sterile gauze. All wells of each plate are then filled with 225 μl of the appropriate medium using a Cetus liquid handling system. Twenty-five microliters (25 μl) of each 1:20 diluted compound is then manually added to row A of a blocked and filled dilution plate. Four compounds, sufficient to supply two test plates, are added per dilution plate. The four compounds are then serially diluted ten-fold from row A through row H using the Cetus liquid handling system. The starting dilution of each compound in row A is, at this point, 1:200. The dilution plates are kept on ice until needed.
Using a multi-channel pipettor with 6 microtips, 100 μl of each drug dilution is transferred to the test plate which already contains 100 μl of medium plus cells. The final dilution, in the test plate, starts at 1:400 (wells B4 through G4). This dilution (to 0.25% DMSO) prevents the DMSO vehicle from interfering with cell growth. Drug-free, infected or uninfected cells (wells B3 through G3) and reagent controls (B2 through G2) receive medium alone. The final two compounds are then transferred from wells H7 through H12 to a second test plate using the same procedure. Test plates are incubated at 37° C. in Air-CO 2 for 7-14 days or until virus controls are lysed as determined macroscopically.
III. Quantitation of Viral
Cytopathogenicity and Drug Activity
A. Materials
1. A solution of 2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide. (XTT)--1 mg./ml solution in media without FCS. Store at 4° C. Prepare weekly.
2. Phenazine methosulfonate (PMS) stock solution--This can be prepared and maintained frozen until needed at -20° C. It should be made in PBS to a concentration of 15.3 mg/ml.
B. Microculture Tetrazolium Assay (MTA)
1. Preparation of XTT-PMS Solution--The XTT-PMS is prepared immediately prior to its addition to the wells of the culture dish. The stock PMS solution is diluted 1:100 (0.153 mg/ml). Diluted PMS is added to every ml of XTT required to give a final PMS concentration of 0.02 mM. A 50 μl aliquot of the XTT-PMS mixture is added to each of the appropriate wells, and the plate is incubated for four hours at 37° C. The plate lids are removed and replaced with adhesive plate sealers (Dynatech cat 001-010-3501). The sealed plate is shaken on a microculture plate mixer and the absorbance is determined at 450 nm.
IV. Results
FIG. 2 depicts a plot of the percentage of test cells over uninfected cells (%) for both infected and uninfected cells as a function of the increasing concentration of compound 14a.
The data plotted on FIG. 2 permit the calculation of an effective concentration (EC 50 ) with respect to infected cells of about 0.15 μg/ml, an inhibitory concentration (IC 50 ) with respect to normal cells of about 100 μg/ml, and a therapeutic index (TI 50 ) of about 667. An earlier assay carried out at the Southern Research Institute yielded a TI 50 of about 200 when MT-2 cells were cultured with H9/HTLV-IIIB.
The HIV inhibitory concentrations of compounds 7a, 9a, 10a, 13a, 14a, and 15a are given on Table III, below.
TABLE III______________________________________HIV Inhibitory Concentrations.sup.aCompound ED.sub.50 (μg/ml)______________________________________ 7a >10 9a 2.310a >1013a 0.4114a 0.1515a 2.9(-)14a.sup. 0.66______________________________________ .sup.a MT2 host cells, except ()14a, which was assayed in CEM cells, exhibiting an IC.sub.50 of 189.
Compound 14a was also found to be active against feline leukemia virus (ED 50 =1.9; FAIDS variant); murine leukemia virus (ED 50 =1.1; Cas-BR-M type) and simian AIDS virus (ED 50 =2.8; D/Washington type).
The invention comprises the biologically active compounds as disclosed or the pharmaceutically acceptable salts or esters thereof, together with a pharmaceutically acceptable carrier for administration in effective non-toxic dose form. Pharmaceutically acceptable salts may be salts of organic acids, such as acetic, lactic, malic or p-toluene sulphonic acid and the like as well as salts of pharmaceutically-acceptable mineral acids, such as hydrochloric or sulfuric acid and the like. Other salts may be prepared and then converted by conventional double decomposition methods into pharmaceutically-acceptable salts directly suitable for purposes of treatment of viral infections in mammals or for the prevention of viral contamination of physiological fluids such as blood or semen in vitro.
Pharmaceutically acceptable carriers are materials useful for the purpose of administering the present analogs and may be solid, liquid or gaseous materials, which are otherwise inert and medically acceptable and are compatible with the active ingredients. Thus, the present active compounds can be combined with the carrier and added to physiological fluids in vitro or administered in vivo parenterally, orally, used as a suppository or pessary, applied topically as an ointment, cream, aerosol, powder, or given as eye or nose drops, etc., depending upon whether the preparation is used for treatment of internal or external viral infections.
For internal viral infections, the compositions may be administered orally or parenterally at effective non-toxic antivirus dose levels of about 10 to 750 mg/kg/day of body weight given in one dose or several smaller doses throughout the day. For oral administration, fine powders or granules may contain diluting, dispersing and/or surface active agents and may be presented in water or in a syrup; in capsules in the dry state, or in a non-aqueous solution or suspension; in tablets or the like. Where desirable or necessary, flavoring, preserving, suspending, thickening, or emulsifying agents may be included. For parenteral administration, administration as drops, the compounds may be presented in aqueous solution in an effective, non-toxic dose in concentration of from about 0.1 to 10 percent w/v. The solutions may contain antioxidants, buffers and the like. Alternatively, for infections of external tissues, the compositions are preferably applied as a topical ointment or cream in concentration of about 0.1 to 10 percent w/v.
Projected Clinical Trial to Evaluate Ability of Compound 14a+AZT to Inhibit the Progression of HIV Infection
AZT administration can decrease mortality and the frequency of opportunistic infection in subjects with AIDS or AIDS-related complex. M. A. Fischl et al. New Engl. J. Med., 317, 185 (1987). Therefore, many persons who have been diagnosed HIV-positive are presently receiving daily doses of AZT. However, AZT is myelotoxic and its administration over a period of 2-3 years has recently been shown to either cause, or to fail to inhibit, a high incidence of the development of non-Hodgkins lymphoma. Therefore, the present study is designed to evaluate the ability of compound (-)14a to inhibit the course of HIV infection.
Patients and Methods
Sixty patients, thirty with HIV infection plus AIDS-related complex and thirty with early AIDS are selected and evaluated in accord with the criteria provided by M. A. Fischl et al., cited above. The two groups of thirty patients are matched into pairs. A capsule containing 100 mg of AZT or an indistinguishable capsule containing 50 mg AZT and 50 mg of (-)14a is administered orally every 4 hours throughout the 24-hour day, for 24 weeks. All of the ARC patients complete the entire study and 20 of the AIDS patients complete the study.
Results
Development of AIDS in ARC Patients
Four patients in the AZT group but none in the AZT+14(a) group develop opportunistic infections or Kaposi sarcoma. Of the four patients in whom AIDS develops: 1 has PCP, candida pneumonia and cerebral toxoplasmosis; 2 have PCP alone and 1 has non-Hodgkins lymphoma in the breast and Kaposi sarcoma in a lymph node. Three of the four patients die 8, 15 and 18 months after diagnosis.
Clinical Progression of AIDS
Nine of the AIDS patients treated with AZT alone die during the study while there is only one death in the population treated with (-)14a plus AZT. During the treatment period, two of fifteen patients who receive the combination regimen worsen while, of the survivors, five of six patients receiving AZT alone worsen. The criteria for response are those of M. A. Fischl et al., cited above.
Discussion
Oral (-)14a +AZT administered in a 1:1 weight ratio is superior to an equivalent amount of AZT in reducing mortality due to early AIDS and the progression of HIV infection in both ARC and early AIDS patients, for a period of up to 6 months. This study also validates the in vitro model used herein to establish the anti-HIV activity of members of this class of carbocyclic nucleosides.
The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention.
|
A therapeutic method is provided, employing an antiviral compound of the general formula: ##STR1## wherein Z is H, OR' or N(R) 2 , wherein R' is H, (C 1 -C 4 )alkyl, aryl, CHO, (C 1 -C 16 )alkanoyl or O═P(OH) 2 , Y is CH or N, and X is selected from the group consisting of H, N(R) 2 , SR, OR' or halogen, wherein R is H, lower (C 1 -C 4 )alkyl, aryl or mixtures thereof, and the pharmaceutically acceptable salts thereof.
| 2
|
FIELD OF THE INVENTION
This invention relates to a device for use in the erection of posts, for example road signs, fence posts and the like.
BACKGROUND OF THE INVENTION
Prior art arrangements for post erection usually entail the digging of an appropriately sized hole, the placement of a post therein and then filling in the hole with concrete to maintain the post in place. Of course, while the cement is drying the post needs to be continually supported. Furthermore, should the post be damaged and need to be replaced, it is necessary to break up the concrete in order to remove the damaged post and replace it with another, undamaged, one.
SUMMARY OF THE INVENTION
It is one object of the present invention to provide apparatus which provides a solid support for posts, which is relatively resistant to a casual vandal, yet enables their speedy erection.
It is another object of the invention to provide a device for use in erection of a pest which allows the post to be readily replaced.
In one aspect the present invention may be considered to provide a device for use in the erection of a post comprising a tubular body portion which is adapted to be firmly installed in a supporting stratum, e.g. the ground, and has an open end adapted to receive a post to be supported, and a resiliently deformable collar having an opening adapted to receive the post and the collar being adapted to be inserted within and engage with the tubular body portion, thus to retain a post inserted therein tight engagement.
The tubular body portion, and collar have generally similar cross-sectional shapes and are preferably circular in cross-section, although they may be of any desired cross-section shape, for example square, The relative dimensions of the body portions, collar and associated post are chosen to be such as permit the collar to be positioned between the tubular body portion and associated post interengaging with each thus to secure the post in the tubular body portion.
The collar is preferably made of a resiliently compressible polymeric material, for example polyurethane or rubber (natural or synthetic).
The tubular body portion is suitably made from metal, but can alternatively be made from any other sufficiently rigid material; in some cases carbon-fibre reinforced plastics material may be suitable. Where the body portion is to be driven into the ground it is important to select a material which can be rammed into the ground without significant damage and which will provide an adequate socket for an associated post.
Suitably, in this case, the tubular body portion provided with a closed or substantially closed end, which is suitably tapered or generally hemispherical shape or other shape suitable to aid penetration, thus to facilitate driving the body portion into the ground.
In another device in accordance with the invention the tubular body portion is adapted to be inserted in a preformed hole, and concreted in place.
The tubular body portion is preferably provided with means, e.g. outwardly projecting flange portions, militating against tilting of the body portion away from a desired orientation when installed, e.g. by a transverse load applied to the post. The body portion may be provided with means militating against rotation of the body portion about its lengthwise axis after it has been installed.
A device in accordance with the invention may comprise interlocking means at an outer surface of the collar and an inner surface of the tubular body portion, adapted to interlock with one another when the collar is properly inserted in the tubular body portion, thus to militate against removal of the collar from the body portion and/or rotation of the collar relative to the body portion. In one embodiment the interlocking means comprise a plurality of resiliently deformable outwardly protruding teeth on the collar and orifices in the body portion in which the teeth engage, in use. In another embodiment the interlocking means comprises one or more lengthwise grooves or recessed in the body port ion and one or more co-operating projections on the collar so that the body portion and the collar may mutually engage in a predetermined orientation. The collar may also comprise a plurality of ridges extending along or generally around the collar, on the inner or outer surface, to provide a good interference fit with the post and body portion respectively, to retain a post in place in the body portion against withdrawal.
In a preferred embodiment the collar comprises an inwardly projecting lip around the post-receiving orifice, adapted to provide a seal militating against ingress of foreign matter between the collar and a post on which the collar is received. The lip may also extend upwardly and have a generally conical external surface to facilitate dispersal of water which may flow down the post.
Whereas the tubular body portion is, in the embodiments described in detail herein, adapted to be inserted in the ground, generally perpendicular to the surface thereof, it will be appreciated that the body portion may be fixed in other strata, for example in a roof or wall structure, or may be arranged to receive a post inclined at an acute angle, e.g. 45° to the surface of the substrate in which the body portion is inserted.
BRIEF DESCRIPTION OF DRAWINGS
Preferred embodiments of the invention will now be described with reference to the following drawings in which like numbers represent like parts and in which
FIG. 1 is an exploded view of a first device embodying the invention, showing a first tubular body portion, a first collar and associated post;
FIGS. 2(a) and 2(b) are, respectively, lengthwise section and plan views of a second collar of a device embodying the invention;
FIGS. 3(a) and 3(b) are, respectively, lengthwise section and plan views of a third collar of a device embodying the invention;
FIGS. 4(a) and 4(b) are, respectively, side and lengthwise section views of a fourth collar of a device embodying the invention; and
FIG. 5 is an exploded view of a device embodying the invention showing a second tubular body portion, fifth collar, and including an inspection pit, adapted to be concreted in place.
FIG. 6 is a perspective view of a third tubular body portion and sixth collar of a device embodying the invention.
FIG. 7 is a view of a device embodying the invention, including a fourth body portion and a seventh two-part collar;
FIG. 8 is a perspective view of a tubular body portion of a device embodying the invention; and
FIG. 9 is an exploded perspective view showing a sixth, rectangular tubular body portion and eighth collar, of a device embodying the invention for use in erecting a barrier.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A first device embodying the invention comprises a first tubular body portion 1 in the form of a metal cylinder, which comprises an open upper end 2, and a closed generally hemispherical opposite end 3. The body portion 1 further comprises a plurality of rectangular orifices 4 in an upper portion thereof, wherein each orifice 4 occupies the same horizontal plane the orifices being generally evenly disposed around the circumference of the body portion. A collar 5 of resiliently deformable material comprises an open ended cylinder, for receiving a post 7, the collar having a plurality of protruding teeth on the outer surface thereof, adapted to be received within the body portion 1 and said teeth being positioned to interlock with the orifices 4 in tight engagement when the collar is inserted into the open end 2 of the body portion 1 with the teeth and orifices in alignment. To this end guide means (not shown) may be provided on the collar 5 and body portion 1 so that the collar can only be inserted in the portion 1 when the teeth 6 and orifices 4 are correctly aligned. Such guide means may conveniently be a lug projecting outwardly of the collar 5, received in a longitudinal groove on the body portion 1; the lug and groove are preferably positioned so that the collar 5 adapts a predetermined position relative to the body portion 1. Alternatively a lug on the body portion i may be received in a groove on the collar.
A preferred collar provides a tight interference fit between tubular body portion and post, thereby to secure the post 7 in position. In preferred collars 5a, 5d lengthwise extending ridges 110 (see FIGS. 2 and 5) are provided on an inner surface defining an opening in which a post is to be received, to facilitate insertion of the post. However, the ridges and grooves can be of any suitable geometry, for example circumferential as the ridges 110a in a third collar (FIG. 3), or even helical (not shown) in other collars of devices embodying, g the invention and may be provided on internal or external surfaces of the collar or, indeed, both surfaces if desired. The ease of insertion and withdrawal when assembling or dismantling the device is dependent on the form and depth of any ridges, to some extent. Furthermore, the use of lengthwise ribs 110 also accommodates slight variations of post size, for example as may arise through manufacturing tolerances. Moulding the collar in two (or more) operations may also provide desired characteristics, e.g. with a relatively rigid annular core, inner and outer surface portions of a somewhat softer, more compressible, preferably high hysteresis, material may provide greater grip to post and body portion than the core material.
The collars of devices embodying the invention are of resiliently deformable material, preferably polyurethane of a suitable hardness: if hardness is too great, assembly is too difficult and if too soft collars tend to collapse. A Shore D hardness of about 65 with a collar minimum wall thickness (i.e. excluding any ridges) of about 5 mm has been found suitable for many applications. Casting of the collars will be difficult, if the wall thickness is too low, as well as providing too little deformation.
The collars may comprise reinforcing means moulded integrally with the collar, for example a wire mesh or any other suitable means e.g. carbon fibre or woven or non-woven textile fibre.
FIGS. 4(a) and 4(b) show a fourth collar 5c for a fourth device embodying the invention. The collar 5c comprises an inwardly projecting lip 15 which projects inwardly around the central opening 17 in which a post is to be received and projects upwardly above the level of a flanged end portion 19 of the collar 5c to form a tight seal; between the collar 5c and post inserted therein whereby to prevent ingress of dirt and any other foreign matter between post 7 and collar 5c; the flange 19 may prevent ingress of foreign matter between the collar 5c and a co-operating tubular body portion. The outer surface 112 of the lip is preferably frustoconical to facilitate shedding of water from the collar.
From an underface of the flange 19 a small lug 20 projects. This lug is adapted to seat in a corresponding recess 22 at the open end portion of a tubular body portion 21, e.g. as shown in FIG. 5, whereby to locate the collar 5c and body portion 21 in a desired orientation around the lengthwise axis of the tubular body portion. This ensures that an opening 24 in the collar 5c is accurately aligned with a corresponding opening 224 (FIGS. 5, 6 and 7) in the body portion so that electrical (or other) services can be introduced through the collar 5c and body portion 21 to the post 7, e.g. for illuminating a sign or operating traffic lights.
The body portion 21 (FIG. 5) comprises upper and lower flanges 26, 28 secured at opposite ends of a tubular core 27. An intermediate flange 29 is also secured to the core and extends part way round it. Adjacent a lower end portion of the core 27 an internal support ring (not shown) may extend around the core and is secured thereto.
The flange 29 is positioned between and parallel to the flanges 26, 28, and lying in a plane perpendicular to a longitudinal axis A of the portion 21. The provision of the additional flange 29 may serve a number of functions, for example if a post of the device is struck, the additional flange may facilitate transfer of the shock to the concrete in which the body portion, 21 is embedded and militate against distortion of the body portion, as well as providing further stability. One or more intermediate flanges may be used, as desired; the plane of any intermediate flange may be other than perpendicular to the axis A and if inclined to the axis may be oriented to provide greatest resistance to impact from a most likely direction, for example if used in the installation of posts on motorway central reservation barriers adjacent one of the carriageways, the direction of traffic on that carriageway. Instead of a single intermediate flange, a helical metal strip (generally in the form of an augur) suitably extending between the flanges 26, 28, or a projecting wire support, or other means, could be welded to or otherwise fixed to the exterior of a tube of the tubular body portion to provide reinforcement and resistance to rotation of the body portion.
In FIG. 6 is shown a device comprising a tubular body portion 21a generally similar to the body portion 21 except that it comprises lengthwise vanes 30 which help to prevent rotation of the body portion and a lengthwise projecting peg 32a, secured to a part of a plate providing the flange 28 within the tube 27 of the body portion positioned to be slidingly received in a lengthwise extending slot 332 in a post 7, to prevent rotation. Prevention of rotation and/or correct orientation of parts may be achieved in other ways, or the post may be locked in position by a bayonet-type joint in which an inwardly projecting peg on the tube portion is received in a slot, suitably L-shaped at the lower end portion of a post by a lengthwise motion, followed by a rotary motion.
FIG. 8 shows a body portion 21c somewhat similar to the body portion 21 but with a complete annular intermediate flange 29a and a lengthwise access slot 224a at the lower end portion instead of the opening 224. An internal support ring 32 extends around the core and is secured to it. When a post is inserted in the body portion 21c the ring 32 is positioned to be engaged by the lower end of the post thus to locate the post lengthwise, spaced from the flange to ensure that wires introduced through the opening 224a are not damaged by the post.
Preferably, where introduction of wiring is necessary, the body portion 21 is installed in association with an inspection pit 200 (FIG. 5). The body portion may be received in a complementary part-cylindrical channel with the opening 224 in the body portion 21 opening directly into the inspection pit 200 through an aligned opening. An appropriate opening may be provided in the post. Preferably, however, the pit 200 is connected to the body portion 21 by an integral conduit 223 which opens into the opening 224 and is secured to the body portion 21 by bolts (not shown). The bolts may, if desired, be pointed and arranged to engage the post. This latter construction using conduit 223 permits a greater mass of concrete to be cast in close proximity with the portion 21. A lid 204, which may be lockable, is provided, The inspection pit 200 is conveniently made of any suitable material, for example a plastics material, e.g. polypropylene. Where a body portion 21a is used wires may be introduced to the post through the open lower end of the post.
FIG. 7 shows a device having a two-part collar 105d, 105e. The upper part 105d may be of any desired configuration, for example as described previously, but as shown comprises a tapering constricted portion 120a remote from the flange 19. If desired the end portion of the collar remote from the flange 19 may be severed to adjust the "grip" afforded by the collar on an inserted pole and this feature may be used on single collars, e.g. collars otherwise similar to the collar 5a, if desired.
The lower part 105e has a tapering entrance portion 122b with a lengthwise extending ridge/grooved portion 123b below the entrance portion 122b. Especially for posts 7e which require deep insertion, the provision of a two part collar reduces costs whilst still providing adequate holding power. The upper or lower part may, if suitably designed, be used alone. Thus a relatively small number of appropriately designed mouldings may, by suitable selection, be used to deal with a wide variety of different.
The body portions 21, 21a, 21b, 21c and 21d shown in FIGS. 5 to 9 are intended to be concreted in place in a preformed hole (which may be dug or made using a suitable augur or boring machine): this is especially useful in some circumstances, e.g. in pedestrian areas in cities which may be paved, for example with appropriately laid bricks or other paving, where it is not possible to ram or hammer a body portion into the ground because that would damage the paving.
In use the body portion 21c is seated at the bottom of a hole excavated in the ground and concrete is poured into the hole around the core 27 and allowed to set to hold the body portion 21 in place. The portion 21 is positioned in a desired orientation so that the opening 224 is correctly oriented for introduction of electrical wiring or other services. The upper flange 26 overlays the surrounding paving or other surface to some extent, hiding the excavation and disrupted paving where the excavation has occurred and presenting an attractive decorative appearance. Although the upper flange 26 in FIGS. 5 and 8 is circular, in a body portion in accordance with the invention, the upper flange may be of any desired shape in plan, e.g. rectangular (FIG. 9) or hexagonal, for example to match the surrounding paving.
The body portion 1 (FIG. 1) is driven into the ground typically by a hydraulic ram (of a type known to those skilled in the art as a hydraulic post inserting machine) up to the extent shown in FIG. 1, leaving the orifices 4 above the surface of the ground.
In a preferred assembly method the appropriate collar is first inserted into the body portion and thereafter the selected pole introduced into the collar and forced home. Preferably a suitable lubricant composition (which may be a soap-based product, for example a mixture of fatty acids and fatty surfactants in an aqueous base with small amounts of solvent and inorganic material) is applied to facilitate the forcing of the post into the collar. Alternatively an appropriate collar is slid onto the base of the selected post 7 and the combination of collar and post forced into engagement with the body portion, (which provides a socket for the post). The assembly is such that the teeth 6 and the orifices 4 interlock (in the FIG. 1 device), or that the collar retains the post in place solely by friction in the other devices. Typically this forced engagement causes slight deformations in the collar 5, which serve to constrict the collar, thus to grip the post 7 firmly. The grip is sufficient to prevent the rotation of the post relative to the body portion, where there are no teeth and to prevent vandals from casually pulling the post out, yet permits the removal of the post by an appropriately equipped person. Such a person would use a pulling tool, common to the art, for directly wrenching out the post, after first applying lubricant, if necessary. Though the collar may occasionally be damaged it is usually possible to remove the post without damage to the collar or body portion, so that the collar can readily be re-used. The collars for common 76 mm diameter traffic sign posts must be a very tight fit to provide satisfactory grip and use of lubricant may be essential. Larger diameter posts, e.g. 115 mm traffic light posts may not require such tight grip (though grip must nevertheless be substantial in view of the greater masses and contact surface area which would normally be involved).
If desired, for example when installing posts for motorway crash barriers, a body portion, for example the body portion 21 may be embedded in a concrete block of a desired shape, conveniently cylindrical and the pre-cast block dropped into a pre-formed hole. Conveniently, using a cylindrical block, a hole may be made using a suitable augur. A removable cap may be placed over the exposed opening in the tubular body portion to prevent ingress of debris during installation whether carried in a pre-cast block or being concreted into a hole into which concrete is poured and allowed to set round the body portion. The pre-cast block, after positioning in the hole is maintained in place by compaction of the surrounding ground.
Various aspects of the body portion 21, e.g. the vanes 30, peg 32a, upper flange 26 and recess 20 may be used in a body portion adapted to be rammed or otherwise driven into the ground as the body portion 1, if desired. Likewise various features of the different collars described herein may be used in devices with body portions adapted to be rammed or otherwise secured in a substratum as appropriate.
Where the body portion is adapted to be installed so that a post secured therein is inclined at an acute angle to the surface of the substratum the upper flange may be inclined at a corresponding angle to the axis of the body portion so that it may seat contiguously with the surface.
The illustrative devices are especially suitable for use in erecting road traffic signs or traffic lights but can be used for other applications involving erection of posts, for example motorway crash barriers, pedestrian barriers (see FIG. 9), security fences, including for example British Rail trackside fences and other fences, supports for overhead cables, e.g. for railway or tram use, and lamp posts, including posts for seasonal lighting, e.g. Christmas, at seaside resorts or in city streets.
In all cases the illustrative devices can be readily installed and provide security against unauthorised removal. The illustrative devices which rely on friction between the collar and post on the one hand and body portion on the other, permit the use of standard posts, without any projections or other interlocking members thus do not require special post constructions for effective operation. It is, of course, necessary to ensure that the friction characteristics are satisfactory and that the physical characteristics of the collar give a desired degree of security, while yet permitting removal and replacement of posts readily, using the correct equipment and that chemical characteristics resist degradation in ambient conditions (which may be very severe in road traffic signs).
|
A device for use in erecting a post. The device comprises a tubular body intended for installation in the ground, e.g. in concrete within a hole, and a deformable collar for tightly retaining a post adapted to interengage with the tubular body in tight engagement. The collar is slightly deformed so as to receive the post and retain it in place. However, with appropriate equipment the post can be readily removed and replaced, for example, if accidentally damaged.
| 4
|
BACKGROUND
[0001] Many game consoles and electronic game tables incorporate a player station at which the player sits or stands. The player station typically includes a video display, which may be an interactive touch screen display. Game controls, audio speakers, selection buttons, card readers, and other control devices, and user interface devices may also form part of the player station.
[0002] Whether a game console or game table has one or many player stations, the player stations are usually assembled as an integral part of the game device. From the manufacturer, the game or table may be shipped with the player stations in place, sometimes requiring a large and heavy shipping crate in which the more sensitive components of the player stations are not especially guarded from handling and shock forces.
[0003] Removal, replacement, and upgrade of a player station usually requires the same skill and labor intensity that dismantling any other integral part of a game machine or game table would require. What is needed is a way to quickly remove and reconnect a player station as a unit, for rapid testing, replacement, cleaning, swapping, and upgrading.
SUMMARY
[0004] A removable player station and locking mechanism. In one implementation, a removable player station allows quick and secure replacement, swapping, and upgrade of a modular player station component for electronic games. In one context, an electronic game table may employ multiple of the removable player stations, each secured with a locking mechanism and a common or a unique lock. In one implementation of a latching mechanism, a pivotable cradle attaches to the electronic game or game table and seats the removable player station through a pivoting motion that also brings the cradle into a locking position. When the pivotable cradle is opened from the locking position, the cradle lifts the removable player station from the game or tabletop for easy manual removal. The accessible part of the locking mechanism may be located under an electronic game tabletop away from view of the players.
[0005] This summary section is not intended to give a full description of removable player stations and locking mechanisms for electronic games, or to provide a list of features and elements. A detailed description of example embodiments follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a diagram of an example electronic game table that includes removable player stations.
[0007] FIG. 2 is a diagram of an example removable player station.
[0008] FIG. 3 is a diagram of an example pivoting latch.
[0009] FIG. 4 is a diagram of an example pivoting cradle with multiple latches and locking capability.
[0010] FIG. 5 is a diagram of an example removable player station and an example pivoting latch in a position for receiving or releasing the removable player station.
[0011] FIG. 6 is a perspective view of an example removable player station and an example pivoting cradle in a position for receiving or releasing the removable player station.
[0012] FIG. 7 is a diagram of an example removable player station and latching mechanism, showing transition from a first position of the latching mechanism for receiving the removable player station to a second position for seating and locking the removable player station.
[0013] FIG. 8 is a diagram of the bottom of the example electronic game table of FIG. 1 , showing accessible locking parts of multiple latching mechanisms for securing multiple removable player stations.
[0014] FIG. 9 is a perspective diagram of an example removable player station that includes computing device components, showing communication ports and a power connection.
DETAILED DESCRIPTION
[0015] Overview
[0016] This disclosure describes removable player stations and associated locking mechanisms for electronic games. As shown in FIG. 1 , various electronic games, such as an electronic game table 100 , e.g., for gambling, may have one or more removable player stations 102 consisting of at least a video display. The video display may be a pure display, or may include touch screen interactive capability. Each removable player station 102 may also include an audio interface, additional game controllers and user interfaces, and other accessories, such as card readers, money processors, and so forth.
[0017] In one implementation, as shown in FIG. 2 , an example removable player station 102 consists of a module that can be quickly secured to or unsecured from electronic game hardware, such as the example electronic game table 100 . For example, the electronic game table 100 may have openings in its tabletop fitted to accept the removable players stations 102 and as shown in FIGS. 3-4 , a latch 300 or latching mechanism 400 that secures each removable player station 102 to the game or electronic game table 100 with very little effort and cable hook-up. In one implementation, the latching mechanism 400 is also referred to herein as a cradle 400 .
[0018] In one implementation, returning to FIG. 1 , each opening or player position at the example electronic game table 100 has a respective associated latching mechanism 400 that receives the removable player station 102 and allows a human operator to quickly secure the removable player station 102 to the electronic game table 100 , e.g., by moving a lever, or pivoting a carriage or cradle. Further, the latching mechanism 400 may include a lock for securing the removable player station to the tabletop of the electronic game table 100 . The lock and the lever parts of the latching mechanism 400 may be located underneath a game tabletop, away from view of the players.
[0019] The removable player station 102 and associated latch 300 and latching mechanisms 400 provide many benefits. Spare removable player station modules 102 may be stocked by a gambling establishment so that faulty player station modules 102 in an electronic game may be quickly replaced. Player stations 102 that become dirty may be swapped out for cleaning and maintenance. The ability to rapidly replace the removable player station modules 102 keeps the electronic game up and running.
[0020] When shipping a large electronic game or game table 100 , the removable player station modules 102 and the quick-release latching mechanisms 400 enable the shipment to be broken down into smaller and lighter pieces that may afford better protection of sensitive components, and then assembled quickly and with minimal effort at the destination.
[0021] The removable player stations 102 also enable a game owner or the manufacturer to upgrade the player stations 102 , without entailing skilled labor or a great deal of labor-hours to swap modules 102 . Likewise, the removable player stations 102 allow an electronic game purchaser to acquire the game at low cost with low-end removable player stations 102 , and effortlessly upgrade to better removable player stations 102 at a later date (e.g., higher resolution video, better audio, more sophisticated game controllers).
[0022] Example Electronic Game Table System
[0023] As introduced above, FIG. 1 shows an example electronic game table 100 that includes removable player stations 102 . In the tabletop of the example electronic game table 100 , each player position has an opening fitted to accept a removable player station 102 . In the shown example, the electronic game table 100 has eight player positions with eight corresponding removable player stations 102 . Thus, the electronic game table 100 also has eight separate latching mechanisms 400 , one for each of the removable player stations 102 .
[0024] The latching mechanism 400 associated with each opening in the tabletop removably secures the removable player station 102 to the electronic game table 100 .
[0025] Example Removable Player Station Module
[0026] As introduced above, FIG. 2 shows an example removable player station module 102 . The removable player station module 102 may have a cosmetic frame 202 that seats flush with the tabletop. Underneath tabletop surface level, the removable player station module 102 has a housing 204 that may contain electronics for the video display or other readout. When the removable player station module 102 constitutes all or part of a computer, the housing 204 may contain computing device components, such as a computing device processor, a computing device memory, or a computing device data storage medium. The housing 204 may also include electronics for additional game controllers and user interfaces, audio speakers, touch screen interface, card readers, and so forth.
[0027] In one implementation, the housing 204 is flanked by a carriage piece 206 on each side of the housing 204 . Between each carriage piece 206 and the housing 204 , a latch receiving member 208 (“receiving member” 208 ) is located for engaging the latch 300 , e.g., of the latching mechanism 400 . Depending upon implementation, the receiving member 208 may pivotably engage the latch 300 . The latch 300 or latching mechanism 400 is movable to engage the receiving member 208 and secure the removable player station 102 to the electronic game table 100 .
[0028] Example Latching and Locking Mechanisms
[0029] FIG. 3 shows the example latch 300 introduced above. In one implementation, each of one or more latches 300 employed to engage and secure the removable player station 102 is a rigid member that has an opening 302 to fit around the receiving member 208 of the removable player station 102 . When the latch 300 is implemented as a pivoting member, a pivot point 304 fixes the latch 300 to the housing 204 and allows rotation around the pivot point 304 . The latch 300 may have a side or end that serves as a lever 306 , enabling a human operator to manually pivot the latch 300 to seat and secure the removable player station 102 .
[0030] FIG. 4 shows the example pivoting cradle 400 introduced above. The shown cradle 400 may have locking capability and multiple latches 300 . In one implementation, the cradle 400 is long enough so that the latches 300 fit on either side of the removable player station 102 . However, in another implementation, the cradle has one or more latches 300 that engage the removable player station 102 through an opening in the housing 204 of the removable player station 102 . Though such an opening, the latch 300 engages an internal receiving member 208 .
[0031] Typically, the removable player station 102 has multiple receiving members 208 on more than one side of the housing 204 to secure the housing 204 to the electronic game table 100 at multiple points on the housing 204
[0032] When a cradle 400 with multiple latches 300 is used, the cradle 400 is attached to the electronic game table 100 at multiple pivot points 304 providing an axis of rotation 402 about which the cradle 400 can be pivoted. Likewise, the lever 306 part of the cradle 400 can be manually gripped at multiple points along the length of the cradle 400 .
[0033] The cradle 400 may also include a lock, or depending on implementation, at least a lock opening 404 for accepting a lock to secure the cradle 400 to the electronic game table 100 in a seated, closed, locked position.
[0034] FIG. 5 shows the removable player station 102 being engaged by a latch 300 of the cradle 400 . As shown, the lever 306 of the latch 300 or cradle 400 is in an open or unsecured position for either receiving or releasing the removable player station 102 .
[0035] The removable player station 102 may include a top piece, such as a cosmetic frame 202 that constitutes the visible edge of the removable player station 102 that a player sees above the top surface 504 of a tabletop 506 of the electronic game table 100 . The visible and accessible part of the latch 300 , cradle 400 , or other latching mechanism may be located underneath the bottom surface 508 of the tabletop 506 , away from view of the players.
[0036] When the cradle 400 pivots to a locking position, the latch(es) 300 of the cradle 400 may be leveraged to pull, via the housing 204 , the cosmetic frame 202 of the removable player station 102 into firm contact with the top surface 504 of the tabletop 506 .
[0037] In an electronic game table 100 for multiple players, each player position at the table 100 has a respective opening for the removable player station 102 at that position. Each latch 300 or cradle 400 includes a pivotable attachment for attaching to the electronic game table 100 within a respective opening in the tabletop 506 .
[0038] FIG. 6 shows a perspective view of the removable player station 102 and a cradle 400 latching mechanism in open position for receiving or releasing the removable player station 102 . Both latches 300 have engaged respective receiving members 208 . In one implementation, a lock opening 404 allows a lock that is attached to the electronic game table 100 to secure the lever 306 of the cradle 400 when the lever is closed in a seated position. In another implementation, the lock mechanism resides on the cradle 400 , and engages a lock opening, latch plate, fastener, etc., on the electronic game table 100 .
[0039] FIG. 7 shows an example removable player station 102 and latching mechanism, in transition from a first position 702 of a latch 300 to a second position 704 of the latch 300 . In the first position 702 , the latch 300 allows the removable player station 102 to be received by or removed from the electronic game table 100 . In the second position, 704 , the latch 300 is seated and enables locking to secure the removable player station 102 .
[0040] The shown latch 300 or cradle 400 pivots to secure the removable player station 102 to the electronic game table 100 . In alternative implementations, alternative latching mechanisms slide, twist, screw, or magnetically capture the housing 204 of the removable player station 204 . A preferred embodiment is the locking quick-release cradle 400 with multiple latches 300 shown in FIGS. 2-9 .
[0041] FIG. 8 shows an example underside arrangement of the example electronic game table 100 of FIG. 1 . Each player position at the table 100 has a corresponding removable player station 102 . In one implementation, on the underside of the table 100 , only the lever 306 and lock/lock opening 404 of each cradle 400 are visible and accessible. The visible and accessible parts of each cradle 400 are hidden from normal view of players at the table. In alternative implementations, the latching mechanism for securing a removable player station 102 to an electronic game table 100 can be accessible from the top of the table 100 or from a side rail of the table.
[0042] FIG. 9 shows a perspective view of an example removable player station 102 that includes computing device components, including communication ports and a power connection. In one implementation, a cable and quick-release plug consolidate two or more connections into a single connector for quick connection or release of the removable player station 102 . For example, a quick release cable with combined plugs may consolidate a power connection and an Ethernet connection; or may consolidate a power connection and a USB connection.
[0043] Conclusion
[0044] Although exemplary systems have been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as exemplary forms of implementing the claimed systems, methods, and structures.
|
A removable player station and locking mechanism. In one implementation, a removable player station allows quick and secure replacement, swapping, and upgrade of a modular player station component for electronic games. In one context, an electronic game table may employ multiple of the removable player stations, each secured with a locking mechanism and a common or a unique lock. In one implementation of a latching mechanism, a pivotable cradle attaches to the electronic game or game table and seats the removable player station through a pivoting motion that also brings the cradle into a locking position. When the pivotable cradle is opened from the locking position, the cradle lifts the removable player station from the game or tabletop for easy manual removal. The accessible part of the locking mechanism may be located under an electronic game tabletop away from view of the players.
| 0
|
This is a Continuation of application Ser. No. 10/956,347, filed Oct. 4, 2004 now abandoned, which in turn is a Continuation of application Ser. No. 09/284,452, filed Jun. 10, 1999 now abandoned, which in turn is a nationalization of PCT/IE97/00067 filed Oct. 15, 1997.
FIELD OF THE INVENTION
This invention relates to an educational teaching aid, and in particular to a soccer ball for the use in coaching soccer ball striking skills.
BACKGROUND OF THE INVENTION
It is well known that striking a soccer ball in different areas causes the soccer ball to travel along different flight paths. Many experienced footballers are very adept at controlling the flight of a soccer ball for passing and scoring during games by striking the soccer ball in a particular area to send the soccer ball along a desired flight path. For example, in a soccer game, when taking a free kick adjacent the penalty area, it is often desirable for an attacking player to curve the soccer ball around a defensive wall of opponent players towards the goal.
Also, different situations call for different types of shot. For example, in a defensive situation, when a defending player is clearing the soccer ball away from his goal area, the objective may be to simply kick the soccer ball as far as possible. In contrast, in an attacking situation, accuracy and good control of the soccer ball flight path, whether kicking a soccer ball directly or along a curved flight path, will be paramount and vital for scoring goals.
Similarly, for heading the soccer ball, in defensive situations a defending player will typically try to head the soccer ball in an upward direction as far away from his own goal as possible. Whereas, in an attacking situation, the attacker will often be trying to head the soccer ball in a downward direction towards the opponents goal.
Whilst anyone can kick a soccer ball, very few have the ability to accurately control the flight of the soccer ball. Soccer coaches often have difficulty in teaching players how to strike the soccer ball correctly to make the various different shots for controlling the soccer ball. This is particularly so with children and younger players generally. Many players find it difficult to follow and understand verbal instructions from the coach as to where to strike the soccer ball to achieve a desired type of shot.
The present invention is directed towards overcoming this problem.
SUMMARY OF THE INVENTION
According to the invention, there is provided a soccer teaching aid comprising a soccer ball having one or more striking targets marked on a surface of the soccer ball, each striking target indicating an area on the surface of the soccer ball where the soccer ball should be struck to send the soccer ball along an associated flight path or trajectory when struck in said target area. The soccer ball according to the invention is particularly advantageous for teaching shot-making skills to a player. The striking targets clearly indicate the area of the soccer ball which needs to be struck by the player to achieve a particular type of shot. The player can readily easily see the target area. From a coaching point of view, all the coach must do is simply tell the player to strike a particular target area on the soccer ball which the player can readily appreciate and execute the required shot.
In a particularly preferred embodiment, each striking target is denoted by a coloured area on the surface of the soccer ball. Ideally, different striking targets are denoted by different coloured areas on the surface of the soccer ball. This is particularly advantageous for clearly showing the target areas. Children particularly will find this much easier to see the target area. It will be appreciated that most conventional soccer balls are either a single colour, usually white, or two-tone, for example having black and white segments. Thus, coaches find it difficult to verbally explain to players to kick the soccer ball in a particular area to achieve a desired shot. In contrast, advantageously with the soccer ball of the present invention, all a coach has to do is instruct the player to kick the soccer bail in the “blue” area, for example, to achieve the shot. The player can readily easily see the area to be struck and therefore execution of the shot is simplified for the player.
Various striking targets may be provided on the soccer ball for striking the soccer ball, for example, to impart side spin to curve the soccer ball to the right or left, to hit the soccer ball low or for achieving long distance or direct shots.
In another embodiment, each striking target is denoted by an arrow marked on the surface of the soccer ball, a head of the arrow pointing to the striking target.
In a further embodiment, each striking target is denoted by a numbered target area on the surface of the soccer ball.
In another embodiment, heading targets are provided on the soccer ball for striking the soccer ball with the head to direct the soccer ball straight ahead, to one side or the other, downwardly, etc.
In a preferred embodiment, the heading targets comprise a central heading target, located centrally on a face of the soccer ball, a right side heading target and a left side heading target on opposite sides of the face of the soccer ball. Preferably, the central heading target has a centre spot surround by a two-part outer ring comprising an upper segment and a lower segment above and below an equator of the soccer ball.
In some cases, indicia such as a line which may, for example, form an equator line, extending around the soccer ball may be provided, again providing a target for the player to hit either above or below the line to keep the soccer ball either low or high in flight respectively.
In a preferred embodiment, a pair of spaced-apart substantially horizontal and parallel target lines extend around the soccer ball defining therebetween a central equatorial band with an upper target area above the band and a lower target area below the band.
In a particularly preferred embodiment, the striking targets comprise a central target located centrally on a face of the soccer ball, a right side-spin striking target and a left side-spin striking target on opposite sides of the face of the soccer ball.
In a further embodiment, the striking targets additionally comprise an upper target area at a top of the face of the soccer ball and a lower target area at a bottom of the face of the soccer ball.
In another embodiment, arrows are denoted on one or more of the striking targets pointing towards the optimum striking position on the striking target. In particular, the arrows may be provided in the right and left side-spin striking targets.
In a further embodiment, the striking targets are denoted by a set of different coloured bands arranged in a cruciform array on a side of the soccer ball. Preferably, arrows of contrasting colour extend outwardly in each coloured band from an inner central portion towards an outer end of the band. Ideally, each arrow is tapered, the arrow increasing in width towards the outer end of the band.
In another aspect, the invention provides a soccer teaching aid as described above in combination with a soccer boot, said soccer boot having defined striking areas denoted on the surface of the boot. Advantageously, the coach can direct a player to strike a particular target area on the soccer ball with a selected striking area on the surface of the boot. Conveniently, the striking areas on the boot may be denoted by different colours so that the coach could, for example, direct the player to hit the “red” target area on the soccer ball with the “blue” striking area of the boot.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more clearly understood by the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:—
FIG. 1 is an elevational view of a soccer ball according to the invention;
FIG. 2 is an elevational view of another soccer ball according to a second embodiment of the invention;
FIG. 3 is an elevational view of a further soccer ball according to a third embodiment of the invention; and
FIG. 4 is an elevational view of another soccer ball according to a fourth embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, and initially to FIG. 1 thereof, there is illustrated a soccer ball according to the invention, indicated generally by the reference numeral 1 . A number of different coloured striking targets are indicated on an outer surface of the soccer ball 1 , each striking target indicating an area on the surface of the soccer ball 1 where the soccer ball should be struck to send the soccer ball 1 along an associated flight path when struck in that target area. In this case, the striking targets comprise a central target 2 for kicking the soccer ball along a generally straight flight path. A right side-spin striking target 3 and a left side-spin striking target 4 are denoted by different colored areas on opposite sides of the soccer ball 1 . By striking the soccer ball within either of the side-spin striking targets 3 , 4 , spin is applied to the soccer ball to curve the flight of the soccer ball.
A pair of spaced-apart substantially parallel and generally horizontal target lines 5 , 6 extend around the soccer ball 1 and are centrally located between a top and a bottom of the soccer ball 1 . The target lines 5 , 6 define therebetween a central equatorial band with an upper striking target area above the band and a lower striking target area below the band. Striking the soccer ball 1 below the line 6 will send the soccer ball in a high arcing shot to achieve long distance. The soccer ball 1 can be struck above the line 5 to send the soccer ball 1 on a relatively low flight path, keeping the soccer ball 1 on or close to the playing surface.
In use, a coach can direct a player to strike the soccer ball 1 in one of the clearly defined striking targets 2 , 3 , 4 to achieve a desired shot. The different colours associated with each striking target 2 , 3 , 4 clearly show the required area on the soccer ball 1 which is to be struck by the player making it easier for the player to follow the coaches instructions to achieve the desired shot. The lines 5 , 6 further assist the coach in clearly directing the player where to strike the soccer ball 1 .
Referring now to FIG. 2 , there is illustrated another soccer ball indicated generally by the reference numeral 10 . The arrangement of striking targets on the surface of the soccer ball 10 is such as to facilitate instruction in correct heading of the soccer ball 10 . In this case, the striking targets comprise a centre spot 11 surrounded by a two-part outer ring comprising an upper segment 12 and a lower segment 13 . The centre spot 11 provides a target for heading the soccer ball 10 along an initially generally horizontal flight path. The upper segment 12 provides a target for heading the soccer ball 10 downwardly and the lower segment 13 provides a target for directing the soccer ball 10 upwardly for maximum flight distance. A right side striking target 14 and a left side striking target 15 are also provided for heading the soccer ball 10 to the left or right respectively. An equator line 16 is marked around the circumference of the soccer ball 10 . Striking the soccer ball 10 above the equator line 16 will tend to urge the soccer ball 10 along a downward flight path, and striking the soccer ball 10 below the equator line 16 will tend to urge the soccer ball upwardly.
Referring now to FIG. 3 , there is illustrated another soccer ball 20 . In this case, the striking targets comprise a central target area 21 , a right side target area 22 , a left side target area 23 , an upper target area 24 and a lower target area 25 . All of the target areas 21 , 22 , 23 , 24 , 25 are in different colours to clearly denote each target area. It will be noted that indicating arrows 26 are provided in the right target area 22 and left target area 23 pointing towards an outermost portion of the target area which it is desirable to strike to impart maximum spin to the soccer ball 20 .
Referring now to FIG. 4 , there is shown another soccer ball 40 . In this case, the striking targets are denoted by sets of different coloured bands 41 , 42 , 43 , 44 arranged in a cruciform array on each side of the soccer ball 40 . Arrows 45 , 46 , 47 , 48 of contrasting colour, in this case white, extend outwardly in each coloured band 41 , 42 , 43 , 44 from a central portion 49 towards an outer end of the band 41 , 42 , 43 , 44 which it is desirable to strike to impart maximum spin to the soccer ball 40 . To emphasise the increased spin imparted as one moves outwardly from the central portion 49 , each arrow 45 , 46 , 47 , 48 is tapered—increasing in width towards the outer end of the band 41 , 42 , 43 , 44 .
It will be appreciated that the invention provides a soccer ball for the use in coaching soccer ball striking skills. The provision of clearly defined coloured striking targets on the soccer ball greatly assists in the coaching of soccer ball striking skills to players, especially young players.
It is envisaged that any suitable method of clearly denoting the striking targets on the surface of the soccer ball may be provided. The striking targets may be numbered if desired to facilitate coaching. What is important is that the striking targets can be easily identified by the coach and the players. While the colouring of the striking targets is particularly desirable to achieve this end, it is envisaged that in some cases, the striking targets may be provided in a single colour on a contrasting background. Arrows and/or numerals may also be used to denote the striking targets.
Similar targets may be provided on opposite sides of the soccer ball. Alternatively different target formations may be provided on opposite sides of the soccer ball. For example the target configurations shown in FIGS. 1 and 2 may be combined on the same soccer ball or possibly the target configurations of FIGS. 2 and 3 may be provided on the same soccer ball.
The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail within the scope of the appended claims.
|
A football teaching aid includes a football having a number of differently colored target areas marked on the surface of the football, each indicating an area on the surface of the football to be struck to send the football along an associated flight path. Thus, in practice, a football coach can direct a player to strike the football in one of the colored target areas, which is easily identified by the player, to achieve a desired shot.
| 0
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on U.S Provisional Patent Application Ser. No. 61/341,025 filed Mar. 26, 2010, and claims benefit thereof.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
REFERENCE TO A SEQUENCE LISTING OR A COMPUTER PROGRAM LISTING
[0004] Not applicable.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0005] The invention relates to the field of aircraft emergency escape equipment, specifically adapted to commercial passenger aircraft with large numbers of passengers. More specifically it relates to an aircraft comprising a detachable passenger escape pods, which are mounted onto the fuselage of the aircraft via a speedily released set of connectors. The pods are equipped with parachutes and airbags and with autonomous mechanisms ensuring their vertical upward detachment from the remainder of the airplane which is thence left to fall to the ground.
[0006] Various arrangements of aircraft emergency equipment have been disclosed in the prior art, that designed to save the lives of passengers and crew in an aircraft which is faced with malfunction, fire or other emergency condition where the airplane is unable to land in a safe fashion.
[0007] The combination of parachute/airbag systems deployed for aircraft emergency landing is known. U.S. Pat. No. 5,836,544, U.S. Pat. No. 5,944,282, DE-43 20 470 or DE-195 07 069 are examples of documents of the prior art wherein are presented alternative types of aircraft or helicopters in which an arrangement of suitably deployed parachutes is used in combination with an arrangement of airbags, so as to respectively ensure smooth descending to the ground and damp at the maximum possible extent the substantial forces being developed upon impact to the ground.
[0008] Parachute/airbag arrangements have been deployed for emergency landing of selected parts of aircraft equipment, such as the jetisonable aircraft fuel tank means proposed in U.S. Pat. No. 4,306,693.
[0009] U.S. Pat. No. 5,356,097, U.S. Pat. No. 5,568,903, FR-855 642 and DE-198 47 546 provide examples in the prior art, wherein is proposed that aircraft may, when emergency conditions arise, be segmented in portions, so as to facilitate safe landing to earth of passengers and/or crew. More particularly, DE-198 47 546 proposes the aircraft to be lengthwise divided in a frontal and a rear portion, wherein under emergency conditions passengers and crew are transferred to the frontal portion which is then laterally cut from the rear portion carrying cargo and fuel. Subsequently the frontal portion is lowered to earth with deployment of a balloon inflated with gas, lighter that the air, on the top thereof, whilst the rear portion falls onto the ground with a pair of parachutes.
[0010] Whilst in the above DE-198 47 546 a lateral division of the aircraft is being proposed, U.S. Pat. No. 5,356,097, U.S. Pat. No. 5,568,903 and FR-855 642 propose varying arrangements of longitudinally detachable portions of the aircraft being lowered to the ground with the aid of parachutes.
[0011] With the exception of U.S. Pat. No. 5,356,097, they however do not disclose usage of airbag impact absorbing means. In all these documents, the detachable aircraft portions are slidably connected onto suitable rails or track of the fuselage and when detached they carry along the tail portion (empennage tail) of the aircraft as well.
[0012] The problem arising with these type of structures is that their detachment from the remainder of the aircraft takes place within a certain period of time necessary for the detachable portion to slide off the fuselage. Even after sliding off, the detached portion may remain for an additional period of time in the vicinity of the remainder of the aircraft, thereby making it possible that an explosion takes place, which is always a possibility under such circumstances. Furthermore the inclusion of the tail portion in the detached portion creates unnecessary excessive load and causes problems in the deployment of parachutes, whereas the exclusion of the cockpit leaves the detachable portion without valuable flight controlling apparatus and instruments.
[0013] U.S. Pat. No. 6,695,257 to Lin shows an ejection escape system for passenger airplane. The disclosure of Lin is expressly and fully incorporated herein by reference. The aircraft body includes a left top cabin cover, a right top cabin cover, and a cockpit, with an ejection device on the left top cabin cover and the right top cabin cover to separate the cabin covers from the fuselage. Ejection mechanisms are included to thrust the cabin covers away from the aircraft, to prevent the cabin covers from interfering with passenger ejection and from striking the aircraft, at such points as the tail wings. Following separation of the left and right cabin covers, individual passenger seats are ejected using conventional ejection seats with parachutes.
[0014] U.S. Pat. No. 6,682,017 to Giannakopoulos shows a pod which is separable from the aircraft, which holds passengers. The disclosure of Giannakopoulos is expressly and fully incorporated herein by reference. The pod is ejected in an emergency. The pod includes a parachute to slow its decent to the earth, and inflatable air bags under the pod to cushion the landing on the ground and provide flotation if the pod lands on water.
BRIEF SUMMARY OF THE INVENTION
[0015] It is an object of the present invention to overcome the deficiencies in the prior art by proposing an aircraft with a series of detachable passenger escape cabins which extend longitudinally along the fuselage of the aircraft, including the cockpit, but excludes the tail portion and whose detachment takes place in the vertical upward direction, thereby effecting an immediate moving away from the vicinity of the remainder of the aircraft wherein there always exists the risk of crash, fire or explosion.
[0016] It is a further object of the present invention to provide an emergency escape system from a commercial aircraft that includes individual escape pods. It should be noted that the invention can be applied to private jets as well. Each pod has its own ejection means, such as conventional rocket motors or explosive devices to propel the pods from the aircraft fuselage. Each pod also has individual parachute means to slow the descent of the pods after ejection, and individual air bags to minimize the shock when the pod collides with the earth. The air bags also provide for flotation should the pod land in water.
[0017] The ejection system is normally controlled by the pilot. However, flight sensors could be utilized to operate the system automatically in an emergency, such as when the plane loses power for a certain period of time or an extreme drop in elevation occurs. Of course, the pilot is given a short time to override any automatic deployment of the system.
[0018] Each pod according to the invention would hold several passengers. In an emergency the pods are ejected and the passenger is provided with oxygen masks as in normal aircraft, to prevent hypoxia.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0019] FIG. 1 shows a commercial aircraft intended to carry a large number of passengers. Left cabin cover ( 2 ) and right cabin cover ( 3 ) separate from fuselage ( 1 ) in an emergency. It is important that the left and right cabin covers ( 2 ) and ( 3 ) are propelled from tail wings ( 4 ) to prevent collision with the plane, which is usually traveling at a high speed towards the cabin covers.
[0020] FIG. 2 shows the cabin covers during separation but before ejection from the aircraft.
[0021] FIG. 3 shows the individual pods after ejection, but before parachutes and air bags have been deployed.
[0022] FIG. 4( a ) shows one pod according to the invention before air bags have been deployed.
[0023] FIG. 4( b ) shows one pod according to the present invention following deployment of the air bags.
[0024] FIG. 4( c ) shows one pod according to the present invention following deployment of both the air bag and parachute, after separation and ejection from the aircraft.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Referring to FIG. 1 , a conventional passenger aircraft ( 1 ) is provided with a left cabin cover ( 2 ) and a right cabin cover ( 3 ). In an emergency situation where a normal landing is either impossible or highly dangerous, the cabin covers ( 2 ) and ( 3 ) are separated from the aircraft and ejected to the left and right of the aircraft ( 1 ). This separation is normally accomplished by the installation of detonator cord along the separation points, such as cords of lead azide. The pilot or co-pilot controls ignition of the detonator cord through electrically controlled squids that ignite the cord. Lead azide burns rapidly and at an extremely high temperature, and burns a separation line where it is embedded in or along the aircraft body. Explosive charges are mounted along the sides of the cabin covers ( 2 ) and ( 3 ) which propel the cabin covers ( 2 ) and ( 3 ) to the left and right of the fuselage, respectively, to prevent the cabin covers ( 2 ) and ( 3 ) from striking the pods or tail wings of the aircraft. Alternatively, the left and right cabin covers could be pushed open by the hydraulic, high-pressure system or blown open explosively.
[0026] FIG. 2 shows the cabin covers ( 2 ) and ( 3 ) during separation from the aircraft. The covers have been partly separated, but not ejected away from the aircraft.
[0027] FIG. 3 shows pods being ejected following complete separation of the cabin covers ( 2 ) and ( 3 ) from the fuselage. Pods ( 4 ) have been ejected from the aircraft by explosive or other hydraulic means. The pods are constructed of a durable polymeric material or reinforced fiberglass, or a light metal such as aluminum, or combinations of these materials. No parachutes have been opened, nor have any airbags been deployed. Because each individual pod operates independently of other pods, except for their escape sequence, the failure of one pod would not cause the failure of the entire ejection sequence. Of course, there is a precise sequenced timing involved in the ejection of individual pods. In this manner the pods are separated to prevent individual pods from colliding, or having their parachute cords becoming entangled. Normal explosive devices, as used in military aircraft, are contemplated for the timing of the sequence. High-pressure lines connect each individual pod. A single detonator, or initiator, fills the high-pressure lines with gas. The pilot fires the initiator, which has a normal mechanical firing mechanism, such as a spring loaded firing pin which strikes a primer, as in a gun. The gas mechanically fires all the explosive devices throughout the aircraft, including the detonator cords for cabin cover separation, explosive devices for cabin cover ejection away from the fuselage, and the various explosive devices at each pod. Precision burning in each explosive device times the individual occurrences in their proper sequence. The entire sequencing and ejection system is independent of any electrical system in the aircraft, so it can function even if electrical systems of the airplane are inoperable.
[0028] FIG. 4(A) shows an individual pod immediately after separation from the aircraft fuselage. Rocket motors numbered ( 5 ) have fired, ejecting the pod from the aircraft. Inflatable bags ( 7 ) are located under explosively removable covers ( 6 ).
[0029] FIG. 4(B) shows an individual pod following explosive removal of the covers ( 6 ). Airbags ( 7 ) have been inflated with gas from gas generating explosive devices. The purpose of the airbags ( 7 ) for flotation should the pod land in water, and to soften impact should the pod land on dry ground.
[0030] Pods ( 4 ) are ejected with conventional rocket motors located between the aircraft fuselage and the pod. Normally the rocket motors will be secured to the bottom of the pod, to expel hot gas at a right angle to the fuselage. Several rocket motors are located on each pod, such as at the four diametrically opposed corners of the pod, perhaps including others symmetrically spaced in the interior of the bottom surface of the pod. It is important that the rocket motors be symmetrical, to keep the pod from being ejected in eccentric paths from the fuselage. Once the pods are ejected that they come with stabilizers that would keep them from turning upside down. These stabilizers can be just pressurized air on each side of the pod. Each pod is provided with a separate, individual tracking beacon which to assist emergency response teams locate the drop zone. It is also contemplated that each pod will be provided with an automated external defibrillator, to help in the event a passenger has heart issues.
[0031] It is important that the pods be secured to the aircraft fuselage by a hydraulic locking mechanism at the bottom of the pod. A hydraulic piston connected to the high pressure hydraulic line will operate the pistons to separate the pods from the fuselage. Alternatively, explosive detonator cords could separate the pods, or explosive bolts as are conventionally used in military aircraft to separate an ejection seat from an aircraft in an emergency.
[0032] Explosive devices are then arranged to open parachutes above each pod, in the same conventional fashion as employed in military aircraft. A rocket motor pulls the parachute in a bag like container above the pod. In a few milliseconds another explosive device opens the bag and pulls the parachute above the pod. Then yet another explosive device opens the parachute. Obviously the sequencing is extremely important, so the timing cords in each explosive device must be properly designed.
[0033] As seen in FIG. 4(C) , explosive devices actuate a parachute sequence. After the parachute is opened, detonator cord opens several covers on the bottom of the pod. Another explosive device fills airbags located in a compartment under the covers on the bottom of the pod. The purpose of the airbag is to soften the shock on landing with the Earth, and to provide flotation if the pod should land on water. FIG. 4(C) shows the pod after ejection, with the parachute and airbags employed.
[0034] It is contemplated that individual pods can represent the various classes of passengers, such as first class, business, etc. In that way, the pods could also function to separate the classes of passengers for the convenience of the passengers and flight attendants.
|
An emergency escape sequence for a commercial aircraft is shown. Individual pods that are separable from the aircraft are ejected individually, following the separation and ejection of the upper cabin from the fuselage. Parachutes are deployed to assist in the safe descent of the pods. Airbags are also deployed to soften the landing and provide flotation in case of a water landing.
| 1
|
CROSS REFERENCE TO RELATED APPLICATIONS
Reference is made to copending, commonly assigned U.S. patent application Ser. No. 11/491,813 to Wu et al., filed Jul. 24, 2006, entitled, “Imaging Member Having Antistatic Anticurl Back Coating”, copending, commonly assigned U.S. patent application Ser. No. 11/491,692 to Wu et al., filed Jul. 24, 2006, entitled, “Imaging Member Having Antistatic Anticurl Back Coating”, copending, commonly assigned U.S. patent application Ser. No. 11/491,691 to Wu et al., filed Jul. 24, 2006, entitled, “Imaging Member Having Antistatic Anticurl Back Coating”, copending, commonly assigned U.S. patent application Ser. No. 11/491,716 to Wu et al., filed Jul. 24, 2006, entitled, “Imaging Member Having Antistatic Anticurl Back Coating”, copending, commonly assigned U.S. patent application Ser. No. 11/491,651 to Wu et al., filed Jul. 24, 2006, entitled, “Imaging Member Having Antistatic Anticurl Back Coating”, copending, commonly assigned U.S. patent application Ser. No. 11/491,764 to Wu et al., filed Jul. 24, 2006, entitled, “Imaging Member Having Antistatic Anticurl Back Coating”, and copending, commonly assigned U.S. patent application Ser. No. 11/492,030 to Wu et al., filed Jul. 24, 2006, entitled, “Imaging Member Having Antistatic Anticurl Back Coating”.
BACKGROUND
The present disclosure relates generally to imaging members, such as layered photoreceptor devices, and processes for making and using the same. The imaging members can be used in electrophotographic, electrostatographic, xerographic and like devices, including printers, copiers, scanners, facsimiles, and including digital, image-on-image, and like devices. More particularly, the embodiments pertain to an imaging member or a photoreceptor that incorporates specific materials, namely polyol esters/amides, into the anticurl back coating (ACBC) layer.
Electrophotographic imaging members, e.g., photoreceptors, typically include a photoconductive layer formed on an electrically conductive substrate. The photoconductive layer is an insulator in the substantial absence of light so that electric charges are retained on its surface. Upon exposure to light, charge is generated by the photoactive pigment, and under applied field charge moves through the photoreceptor and the charge is dissipated.
In electrophotography, also known as xerography, electrophotographic imaging or electrostatographic imaging, the surface of an electrophotographic plate, drum, belt or the like (imaging member or photoreceptor) containing a photoconductive insulating layer on a conductive layer is first uniformly electrostatically charged. The imaging member is then exposed to a pattern of activating electromagnetic radiation, such as light. Charge generated by the photoactive pigment move under the force of the applied field. The movement of the charge through the photoreceptor selectively dissipates the charge on the illuminated areas of the photoconductive insulating layer while leaving behind an electrostatic latent image. This electrostatic latent image may then be developed to form a visible image by depositing oppositely charged particles on the surface of the photoconductive insulating layer. The resulting visible image may then be transferred from the imaging member directly or indirectly (such as by a transfer or other member) to a print substrate, such as transparency or paper. The imaging process may be repeated many times with reusable imaging members.
An electrophotographic imaging member may be provided in a number of forms. For example, the imaging member may be a homogeneous layer of a single material such as vitreous selenium or it may be a composite layer containing a photoconductor and another material. In addition, the imaging member may be layered. These layers can be in any order, and sometimes can be combined in a single or mixed layer.
Typical multilayered photoreceptors have at least two layers, and may include a substrate, a conductive layer, an optional charge blocking layer, an optional adhesive layer, a photogenerating layer (sometimes referred to as a “charge generation layer,” “charge generating layer,” or “charge generator layer”), at least one charge transport layer, an optional overcoating layer and, in some belt embodiments, an anticurl backing layer. In the multilayer configuration, the active layers of the photoreceptor are the charge generation layer (CGL) and the charge transport layer (CTL). Enhancement of charge transport across these layers provides better photoreceptor performance.
As more advanced, higher speed electrophotographic copiers, duplicators and printers were developed, however, degradation of image quality was encountered during extended cycling. The complex, highly sophisticated duplicating and printing systems operating at very high speeds have placed stringent requirements, including narrow operating limits, on the imaging members.
In multilayered imaging members, the CTL is usually the last layer to be coated and is applied by solution coating then followed by drying the wet applied coating at elevated temperatures of about 120° C., and finally cooling it down to room ambient temperature of about 25° C. When a production web stock of several thousand feet of coated multilayered photoreceptor material is obtained after finishing application of the CTL coating through drying and cooling processes, exhibition of spontaneous upward curling of the multilayered photoreceptor is observed. This upward curling is a consequence of thermal contraction mismatch between the CTL and the substrate support. Since the CTL in a typical photoreceptor device has a coefficient of thermal contraction approximately 3.7 times greater than that of the flexible substrate support, the CTL does therefore have a larger dimensional shrinkage than that of the substrate support as the imaging member web stock cools down to ambient room temperature. The exhibition of imaging member curling after completion of CTL coating is due to the consequence of the heating/drying/cooling processing.
To offset the curling, an anticurl back coating is then applied to the backside of the flexible substrate support, opposite to the side having the charge transport layer, and render the imaging member web stock with desired flatness. Curling of a photoreceptor web is undesirable because it hinders fabrication of the web into cut sheets and subsequent welding into a belt. An anticurl back coating having a counter curling effect equal to and in the opposite direction to the applied layers is applied to the reverse side of the active imaging member to eliminate the overall curl of the coated device by offsetting the curl effect which is arisen from the mismatch of the thermal contraction coefficient between the substrate and the CTL, resulting in greater CTL dimensional shrinkage than that of the substrate.
Although the anticurl back coating is needed to counteract and balance the curl so as to allow the imaging member web to lay flat, nonetheless, common formulations used for anticurl back coatings have often been found to provide unsatisfying dynamic imaging member belt performance under a normal machine functioning condition; for example, exhibition of excessive anticurl back coating wear and its propensity to cause electrostatic charge buildup are the frequently seen problems that prematurely cut short the service life of the photoreceptor belt and require its frequent costly replacement in the field.
Moreover, high surface contact friction of the anticurl back coating against all these machine subsystems is further been found to cause the development of electrostatic charge buildup problem. In many machines, the electrostatic charge builds up due to high contact friction between the anticurl back coating and the backer bars is seen to significantly increase the frictional force to the point that it requires higher torque from the driving motor to pull the belt for effective cycling motion. In full color electrophotographic machines, using a 10-pitch photoreceptor belt, this electrostatic charge build-up can be extremely high due to large number of backer bars used in the machine.
In an effort to resolve the problems associated with the anticurl back coating, one known wear resistance anticurl back coating formulated for use in the printing apparatuses includes organic particles reinforcement such as the utilization of polytetrafluoroethylene (PTFE) dispersion in the anticurl back coating polymer binder. PTFE particles are commonly incorporated to reduce the friction between the anticurl back coating of the belt and the backer bars. The benefit of using this formulation is, however, outweighed by the instability of the PTFE particle dispersion in the anticurl back coating solution. PTFE, being two times heavier than the coating solution, forms an unstable dispersion in a polymer coating solution, commonly a bisphenol A polycarbonate polymer solution, and tends to settle with particles flocculate themselves into big agglomerates in the mix tanks if not continuously stirred. The difficulty of achieving good PTFE dispersion in the coating solution poses a problem, because it can result in an anticurl back coating with insufficient and variable or inhomogeneous PTFE dispersion along the length of the coated web, and thus, inadequate reduction of friction over the backer bars in the copiers or printers. This causes significant complications in the larger copiers or printers, which often include so many backer bars that the high friction increases the torque needed to drive the belt. Consequently, two driving rollers are included and synchronized to prevent any registration error to occur. The additional components result in high costs for producing and using these larger printing apparatuses. Thus, if the friction could be reduced, the apparatus design in these larger printing apparatuses could be simplified with less components, resulting in significant cost savings.
Some anticurl back coating formulations are disclosed in U.S. Pat. Nos. 5,069,993, 5,021,309, 5,919,590, 4,654,284 and 6,528,226. However, while these formulations serve their intended purposes, further improvement on those formulations are desirable and needed. More particularly, there is a need, which is addressed herein, for a way to create an anticurl back coating formulation that has intrinsic properties to minimize or eliminate charge accumulation in photoreceptors without sacrificing the other electrical properties.
The term “electrostatographic” is generally used interchangeably with the term “electrophotographic.” In addition, the terms “charge blocking layer” and “blocking layer” are generally used interchangeably with the phrase “undercoat layer.”
SUMMARY
According to embodiments illustrated herein, there is provided a way in which print quality is improved, for example, static electricity generally due to the triboelectric effect is reduced or substantially eliminated in imaging systems.
According to embodiments illustrated herein, there is also provided a way in which print quality is improved, for example, the wear resistance is improved and the friction is reduced between the anticurl back coating of the belt and the backer bars in imaging systems. In one embodiment, there is provided an imaging member comprising a substrate, a charge generating layer disposed on the substrate, at least one charge transport layer disposed on the charge generating layer, and an anticurl back coating disposed on the substrate on a side opposite to the charge transport layer, the anticurl back coating comprising a polyol ester or polyol amide.
An imaging member, comprising a substrate, a charge generating layer disposed on the substrate, at least one charge transport layer disposed on the charge generating layer, and an anticurl back coating disposed on the substrate on a side opposite to the charge transport layer, the anticurl back coating comprising a polyol ester or a polyol amide, wherein the polyol ester is generated from the reaction of a polyol containing at least one hydroxyl group and a monobasic acid or an acid halide, and wherein the polyol amide is generated from the reaction of a polyamine containing at least one amine group and a monobasic acid or an acid halide.
There is also provided an image forming apparatus for forming images on a recording medium comprising an imaging member having a charge retentive-surface for receiving an electrostatic latent image thereon, a development component for applying a developer material to the charge-retentive surface to develop the electrostatic latent image to form a developed image on the charge-retentive surface, a transfer component for transferring the developed image from the charge-retentive surface to a copy substrate, and a fusing component for fusing the developed image to the copy substrate. In such embodiments, the imaging member of the image forming apparatus comprises a substrate, a charge generating layer disposed on the substrate, at least one charge transport layer disposed on the charge generating layer, and an anticurl back coating disposed on the substrate on a side opposite to the charge transport layer, the anticurl back coating comprising a polyol ester or polyol amide.
DETAILED DESCRIPTION
It is understood that other embodiments may be utilized and structural and operational changes may be made without departure from the scope of the embodiments disclosed herein.
The embodiments relate to an imaging member or photoreceptor that incorporates a polyol ester or polyol amide to the formulation of an anticurl back coating that helps reduce, or substantially eliminates, electrostatic charge buildup caused by friction with the backer plates and rollers.
The embodiments relate to an imaging member or photoreceptor that incorporates a polyol ester or polyol amide to the formulation of an anticurl back coating that helps reduce friction and improves wear resistance caused by contact with the backer plates and rollers.
According to embodiments herein, an electrophotographic imaging member is provided, which generally comprises at least a substrate layer, an imaging layer disposed on the substrate, and an overcoat layer disposed on the imaging layer. The imaging member may include, as imaging layers, a charge transport layer or both a charge transport layer and a charge generation layer. The imaging member can be employed in the imaging process of electrophotography, where the surface of an electrophotographic plate, drum, belt or the like (imaging member or photoreceptor) containing a photoconductive insulating layer on a conductive layer is first uniformly electrostatically charged. The imaging member is then exposed to a pattern of activating electromagnetic radiation, such as light. The radiation selectively dissipates the charge on the illuminated areas of the photoconductive insulating layer while leaving behind an electrostatic latent image. This electrostatic latent image may then be developed to form a visible image by depositing oppositely charged particles on the surface of the photoconductive insulating layer. The resulting visible image may then be transferred from the imaging member directly or indirectly (such as by a transfer or other member) to a print substrate, such as transparency or paper. The imaging process may be repeated many times with reusable imaging members.
In a typical electrostatographic reproducing apparatus such as electrophotographic imaging system using a photoreceptor, a light image of an original to be copied is recorded in the form of an electrostatic latent image upon a imaging member and the latent image is subsequently rendered visible by the application of a developer mixture. The developer, having toner particles contained therein, is brought into contact with the electrostatic latent image to develop the image on an electrostatographic imaging member which has a charge-retentive surface. The developed toner image can then be transferred to a copy substrate, such as paper, that receives the image via a transfer member.
Alternatively, the developed image can be transferred to another intermediate transfer device, such as a belt or a drum, via the transfer member. The image can then be transferred to the paper by another transfer member. The toner particles may be transfixed or fused by heat and/or pressure to the paper. The final receiving medium is not limited to paper. It can be various substrates such as cloth, conducting or non-conducting sheets of polymer or metals. It can be in various forms, sheets or curved surfaces. After the toner has been transferred to the imaging member, it can then be transfixed by high pressure rollers or fusing component under heat and/or pressure.
Illustrated herein are embodiments of an imaging member comprising a substrate, a charge generating layer disposed on the substrate, at least one charge transport layer disposed on the charge generating layer, and an anticurl back coating disposed on the substrate on a side opposite to the charge transport layer, the anticurl back coating comprising a polyol ester or polyol amide. The polyol ester or polyol amide is incorporated into the anticurl back coating to reduce electrostatic charge buildup in the imaging member. Polyol esters/amides make the anticurl back coating surface or the entire layer itself slightly conductive.
In embodiments, polyol esters such as glycerol fatty acid esters can, for example, be referred to as an ester generated from the reaction of a polyol containing one or more hydroxyl groups in one molecule with one or plural monobasic acids or acid halides. Suitable polyol examples may be selected from saturated and unsaturated straight and branched chain linear aliphatic; saturated and unsaturated cyclic aliphatics, including heterocyclic aliphatic; or mononuclear or polynuclear aromatics, including heterocyclic aromatics alcohols. Polyols with one hydroxyl group include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, ethoxy ethanol, propoxy ethanol, butoxy ethanol, ethoxy propanol, propoxy propanol, butoxy propanol, ethoxy butanol, propoxy butanol, and butoxy butanol. Polyols with two or more hydroxyl groups include hindered alcohols with for example, from about 5 to about 30 carbon atoms, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, neopentyl glycol, 2,2-diethyl propane-1,3-diol, 2,2-dibutyl propane-1,3-diol, 2-methyl-2-propyl propane-1,3-diol, 2-ethyl-2-butyl propane-1,3-diol, trimethylol ethane, trimethylol propane, ditrimethylol propane, tritrimethylol propane, tetratrimethylol propane, pentaerythritol, dipentaerythritol, tripentaerythritol, tetrapentaerythritol, and pentapentaerythritol, or mixtures thereof. Specific hindered alcohols are those with from about 5 to about 10 carbon atoms such as trimethylol propane, ditrimethylol propane, pentaerythritol, dipentaerythritol, and tripentaerythritol. Polyols also include carbohydrate molecules, such as monosaccharides including, for example, mannose, galactose, arabinose, xylose, ribose, apiose, rhamnose, psicose, fructose, sorbose, tagitose, ribulose, xylulose, and erythrulose. Oligosaccharides include, for example, maltose, kojibiose, nigerose, cellobiose, lactose, melibiose, gentiobiose, turanose, rutinose, trehalose, sucrose and raffinose. Polysaccharides include, for example, amylose, glycogen, cellulose, chitin, inulin, agarose, zylans, mannan and galactans. Although perhaps sugar alcohols may not be considered carbohydrates, the naturally occurring sugar alcohols are very closely related to carbohydrates. Examples of sugar alcohols are sorbitol, mannitol and galactitol.
Examples of the monobasic acids include saturated aliphatic carboxylic acids, such as acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, pivalic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid and palmitic acid; unsaturated aliphatic carboxylic acids, such as stearic acid, acrylic acid, propionic acid, crotonic acid and oleic acid; and cyclic carboxylic acids, such as benzoic acid, toluic acid, napthoic acid, cinnamic acid, cyclohexanecarboxylic acid, nicotinic acid, isonicotinic acid, 2-furoic acid, 1-pyrrolecarboxylic acid, monoethyl malonate and ethyl hydorgenphthalate. Suitable saturated fatty acids include, for example, capric, lauric, palmitic, stearic, behenic, isomyristic, isomargaric, myristic, caprylic, and anteisoarachadic. Suitable preferred unsaturated fatty acids include, for example, maleic, linoleic, licanic, oleic, linolenic, and erydiogenic acids. Mixtures of fatty acids derived from soybean oil, palm oil, coconut oil, cottonseed and fatty hydrogenated rapeseed oil can also be selected. Examples of acid halides, such as acid chlorides, include the chlorides of the monobasic acids.
Specific examples of polyol esters are neopentyl glycol as NPG, trimethylol propane as TMP, ditrimethylol propane as DTMP, pentaerythritol as PE, dipentaerythritol as DPE, and tripentaerythritol as TPE). In embodiments there can be selected NPG-di(n-butanoate), NPG-di(2-methylpropanoate), NPG-di(n-pentanoate), NPG-di(2-methylbutanoate), NPG-di(n-hexanoate), NPG-di(2-ethylbutanoate), NPG-di(3-ethylbutanoate), NPG-di(n-heptanoate), NPG-di(2-ethylpentanoate), NPG-di(n-octanoate), NPG-di(2-ethylhexanoate), NPG-di(n-nonanate), NPG-di(isononanate), NPG-di(n-decanoate), NPG-di(mixed(n-hexanoate, n-butanoate)), NPG-di(mixed(n-hexanoate, n-pentanoate)), NP di(mixed(n-butanoate, n-heptanoate)), TMP-tri(n-butanoate), TMP-tri(2-methylpropanoate), TMP-tri(n-pentanoate), TMP-tri(2-methylbutanoate), TMP-tri(n-hexanoate), TMP-tri(3-ethylbutanoate), TMP-tri(n-heptanoate), TMP-tri(2-ethylpentanoate), TMP-tri(n-octanoate), TMP-tri(2-ethylhexanoate), TMP-tri(n-nonanate), TMP-tri(isononanate), TMP-tri(n-decanoate), TMP-tri(isodecanoate), TMP-tri(mixed(n-butanoate, n-hexanoate)), DTMP-tetra(n-butanoate), DTMP-tetra(2-methylpropanoate), DTMP-tetra(n-pentanoate), DTMP-tetra(2-methylbutanoate), DTMP-tetra(n-hexanoate), DTMP-tetra(3-ethylbutanoate), DTMP-tetra(n-heptanoate), DTMP-tetra(2-ethylhexanoate), DTMP-tetra(n-octanoate), DTMP-tetra(2-ethylhexanoate), DTMP-tetra(n-nonanate), DTMP-tetra(isononanate), DTMP-tetra(n-decanoate), DTMP-tetra(isodecanoate), DTMP-tetra[mixed(n-butanoate, n-hexanoate)], DTMP-tetra[mixed(n-pentanoate, isohexanoate)], PE-tetra(n-butanoate), PE-tetra(2-methylpropanoate), PE-tetra(n-pentanoate), PE-tetra(2-methylbutanoate), PE-tetra(2,2-dimethylpropanoate), PE-tetra(n-hexanoate), PE-tetra(2-ethylbutanoate), PE-tetra(2,2-dimethylbutanoate), PE-tetra(n-heptanoate), PE-tetra(2-ethylpentanoate), PE-tetra(n-octanoate), PE-tetra(2-ethylhexanoate), PE-tetra(n-nonanate), PE-tetra(isononanate), PE-tetra(n-decanoate), PE-tetra(isodecanoate), PE-tetra(n-decanoate), PE-tetra(isodecanoate), PE-tetra[mixed(n-pentanoate, isopentanoate, n-hexanoate, n-butanoate)], PE-tetra[mixed(n-pentanoate, isopentanoate, n-heptanoate, n-nonanate)], DPE-hexa(n-butanoate), DPE-hexa(2-methylpropanoate), DPE-hexa(n-pentanoate), DPE-hexa(2-methylbutanoate), DPE-hexa(3-methylbutanoate), DPE-hexa(2,2-dimethylpropanoate), DPE-hexa(n-hexanoate), DPE-hexa(2-ethylbutanoate), DPE-hexa(2,2-dimethylbutanoate), DPE-hexa(n-heptanoate), DPE-hexa(2-ethylpentanoate), DPE-hexa(n-octanoate), DPE-hexa(2-ethylhexanoate), DPE-hexa(n-nonanate), DPE-hexa(isononanate), DPE-hexa(n-decanoate), DPE-hexa[mixed(n-pentanoate, isopentanoate, n-heptanoate, n-nonanate)], TPE-octa(n-butanoate), TPE-octa(2-methylpropanoate), TPE-octa(n-pentanoate), TPE-octa(2-methylbutanoate), TPE-octa(2,2-dimethylpropanoate), TPE-octa(n-hexanoate), TPE-octa(2-ethylbutanoate), TPE-octa(n-octanoate), TPE-tetra(2-ethylhexanoate), TPE-octa(n-nonanate), TPE-octa(isononanate), TPE-octa(n-decanoate), TPE-octa[mixed(n-pentanoate, isopentanoate, hexanoate, n-butanoate)], TPE-octa[mixed(isopentanoate, n-hexanoate)], TPE-octa[mixed(n-pentanoate, isopentanoate, n-heptanoate, n-nonanate)]esters of PE, and a mixture containing linear and branched aliphatic acids of, for example, from about 4 to about 10 carbon atoms. Examples of polyol esters also include a neopentyl glycol caprylate caprate mixed ester, a trimethylolpropane valerate heptanoate mixed ester, a trimethylolpropane decanoate octanoate mixed ester, trimethylolpropane nananoate, and a pentaerythritol heptanoate caprate mixed ester. Specifically, in embodiments a polyol ester with about than 4 or less, including no hydroxyl groups can be selected.
Moreover, polyol esters, and/or dibasic acid esters can be incorporated into top layer of the imaging member. Dibasic acid esters include an adipate, azelate, sebacate, 1,9-nonamethylene dicarboxylic acid ester and so on. A complex ester can also be selected. As an alcohol for the dibasic acid ester, a linear or branched, a mono- or polyhydric aliphatic alcohol with, for example, from about 4 to about 20, or from about 8 to about 14 carbon atoms can be utilized. Examples of dibasic acid esters include dioctyl adipate, dioctyl sebacate, diisodecyl adipate, and didecyl adipate. As the organic ester, a polyol ester is selected.
In various embodiments, examples of polyol esters include ZELEC™ 887 (trimethylpropane tricaprylate), ZELEC™ 874 (pentaerythrityl tetracaprylate), STEPAN™ BES (butoxy ethyl stearate), STEPAN™ PEG 400 DO (polyethylene glycol dioleate), all available from STEPAN Company, Northfield, Ill.; HOSTASTAT™ FE20liq (glycerol fatty acid ester), available from Clariant Corporation, Charlotte, N.C.
In embodiments, polyol amides such as glycerol fatty acid amides can, for example, be referred to as an amide generated from the reaction of a polyamine containing one or more amine groups in one molecule with one or plural monobasic acids or acid halides. Examples of polyol amides include NINOL® 201 (produced by condensing one mole of oleic acid with two moles of diethanolamine), C-5 (formerly AMIDOX® C-5, polyethylene glycol cocamide), all available from STEPAN Company, Northfield, Ill.
In embodiments, polyol ester or polyol amide, like the examples named above, are incorporated into conventional photoreceptor surface layers, namely, the anticurl back coating. The coating formulation may, but need not, include PTFE, silica or other like conventional particles used to improve the mechanical properties of the layer. The polyol ester or polyol amide is physically mixed or dispersed into the anticurl back coating solutions or dispersions used to form the eventual anticurl back coating layer in the imaging member.
The polyol ester or polyol amide is generally present in the anticurl back coating at a weight concentration of from about 0.1 percent to about 50 percent, from about 5 percent to about 40 percent, and from about 10 percent to about 30 percent by weight of the total weight of the anticurl back coating.
In various embodiments, the anticurl back coating has a thickness of from about 1 to about 100, or from about 5 to about 50, or from about 10 to about 30 microns.
In embodiments, the polyol ester or polyol amide is physically mixed or dispersed into the anticurl back coating formulation. Some methods that can be used to incorporate a polyol ester or polyol amide into a formulation to form an anticurl back coating include the following: (1) simple mixing of a polyol ester or polyol amide, with an anticurl back coating formulation, with the formulation being previously dispersed before adding the polyol ester or polyol amide (2) milling the polyol ester or polyol amide with the anticurl back coating formulation.
After forming the dispersion for the anticurl back coating, the dispersion is coated on the imaging member substrate. The coating having the added polyol ester or polyol amide is applied onto the substrate and subsequently dried to form the anticurl back coating layer. The anticurl back coating may be applied or coated onto a substrate by any suitable technique known in the art, such as spraying, dip coating, draw bar coating, gravure coating, silk screening, air knife coating, reverse roll coating, vacuum deposition, chemical treatment and the like. Additional vacuuming, heating, drying and the like, may be used to remove any solvent remaining after the application or coating to form the anticurl back coating.
Illustrative examples of substrate layers selected for the imaging members of the present invention may be opaque or substantially transparent, and may comprise any suitable material having the requisite mechanical properties. Thus, the substrate may comprise a layer of insulating material including inorganic or organic polymeric materials, such as MYLAR a commercially available polymer, MYLAR-containing titanium, a layer of an organic or inorganic material having a semiconductive surface layer, such as indium tin oxide, or aluminum arranged thereon, or a conductive material inclusive of aluminum, aluminized polyethylene terephthalate, titanized polyethylene chromium, nickel, brass or the like. The substrate may be flexible, seamless, or rigid, and may have a number of many different configurations, such as for example a plate, a cylindrical drum, a scroll, an endless flexible belt, and the like. In one embodiment, the substrate is in the form of a seamless flexible belt. The anticurl back coating is applied to the back of the substrate. Moreover, the substrate may contain thereover an undercoat layer in some embodiments, including known undercoat layers, such as suitable phenolic resins, phenolic compounds, mixtures of phenolic resins and phenolic compounds, titanium oxide, silicon oxide mixtures like TiO 2 /SiO 2 .
The thickness of the substrate layer depends on many factors, including economical considerations, thus this layer may be of substantial thickness, for example over 3,000 microns, or of minimum thickness providing there are no significant adverse effects on the member. In embodiments, the thickness of this layer is from about 75 microns to about 300 microns.
In embodiments, the undercoat layer may also contain a binder component. Examples of the binder component include, but are not limited to, polyamides, vinyl chlorides, vinyl acetates, phenolic resins, polyurethanes, aminoplasts, melamine resins, benzoguanamine resins, polyimides, polyethylenes, polypropylenes, polycarbonates, polystyrenes, acrylics, styrene acrylic copolymers, methacrylics, vinylidene chlorides, polyvinyl acetals, epoxys, silicones, vinyl chloride-vinyl acetate copolymers, polyvinyl alcohols, polyesters, polyvinyl butyrals, nitrocelluloses, ethyl celluloses, caseins, gelatins, polyglutamic acids, starches, starch acetates, amino starches, polyacrylic acids, polyacrylamides, zirconium chelate compounds, titanyl chelate compounds, titanyl alkoxide compounds, organic titanyl compounds, silane coupling agents, and combinations thereof. In embodiments, the binder component comprises a member selected from the group consisting of phenolic-formaldehyde resin, melamine-formaldehyde resin, urea-formaldehyde resin, benzoguanamine-formaldehyde resin, glycoluril-formaldehyde resin, acrylic resin, styrene acrylic copolymer, and mixtures thereof.
In embodiments, the undercoat layer may contain an optional light scattering particle. In various embodiments, the light scattering particle has a refractive index different from the binder and has a number average particle size greater than about 0.8 μm. In various embodiments, the light scattering particle is amorphous silica P-100 commercially available from Espirit Chemical Co. In various embodiments, the light scattering particle is present in an amount of about 0% to about 10% by weight of a total weight of the undercoat layer.
In embodiments, the undercoat layer may contain various colorants. In various embodiments, the undercoat layer may contain organic pigments and organic dyes, including, but not limited to, azo pigments, quinoline pigments,.perylene pigments, indigo pigments, thioindigo pigments, bisbenzimidazole pigments, phthalocyanine pigments, quinacridone pigments, quinoline pigments, lake pigments, azo lake pigments, anthraquinone pigments, oxazine pigments, dioxazine pigments, triphenylmethane pigments, azulenium dyes, squalium dyes, pyrylium dyes, triallylmethane dyes, xanthene dyes, thiazine dyes, and cyanine dyes. In various embodiments, the undercoat layer may include inorganic materials, such as amorphous silicon, amorphous selenium, tellurium, a selenium-tellurium alloy, cadmium sulfide, antimony sulfide, titanium oxide, tin oxide, Zinc oxide, and zinc sulfide, and combinations thereof.
In embodiments, the thickness of the undercoat layer may be from about 0.1 to 30 microns.
A photoconductive imaging member herein can comprise in embodiments in sequence of a supporting substrate, an undercoat layer, an adhesive layer, a charge generating layer and a charge transport layer. For example, the adhesive layer can comprise a polyester with, for example, an M w of about 70,000, and an M n of about 35,000.
Examples of the binder materials selected for the charge transport layers include components, such as those described in U.S. Pat. No. 3,121,006, the disclosure of which is totally incorporated herein by reference. Specific examples of polymer binder materials include polycarbonates, polyarylates, acrylate polymers, vinyl polymers, cellulose polymers, polyesters, polysiloxanes, polyamides, polyurethanes, poly(cyclo olefins), and epoxies, and random or alternating copolymers thereof. In embodiments electrically inactive binders are comprised of polycarbonate resins with for example a molecular weight of from about 20,000 to about 100,000 and more specifically with a molecular weight M w of from about 50,000 to about 100,000. Examples of polycarbonates are poly(4,4′-isopropylidene-diphenylene)carbonate (also referred to as bisphenol-A-polycarbonate, poly(4,4′-cyclohexylidinediphenylene) carbonate (referred to as bisphenol-Z polycarbonate), poly(4,4′-isopropylidene-3,3′-dimethyl-diphenyl)carbonate (also referred to as bisphenol-C-polycarbonate) and the like. In embodiments, the charge transport layer, such as a hole transport layer, may have a thickness from about 10 to about 55 microns.
The charge transport layers can comprise in embodiments aryl amine molecules, and other known charge components. For example, a photoconductive imaging member disclosed herein may have charge transport aryl amines of the following formula:
wherein x is alkyl, and wherein the aryl amine is dispersed in a resinous binder. In another embodiment, imaging member may have an aryl amine wherein x is methyl, a halogen that is chloride, and a resinous binder selected from the group consisting of polycarbonates and polystyrene. In yet another embodiment, the photoconductive imaging member has an aryl amine that is N,N′-diphenyl-N,N-bis(3-methylphenyl)-1,1′-biphenyl4,4′-diamine.
The charge transport aryl amines can also be of the following formula:
wherein X and Y are independently alkyl, alkoxy, aryl, a halogen, or mixtures thereof. Alkyl and alkoxy can contain for example from 1 to about 25 carbon atoms, and more specifically from 1 to about 12 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, and the corresponding alkoxides. Aryl can contain from 6 to about 36 carbon atoms, such as phenyl, and the like. Halogen includes chloride, bromide, iodide and fluoride. Substituted alkyls, alkoxys, and aryls can also be selected in embodiments.
Examples of specific aryl amines include N,N′-diphenyl-N,N′-bis(alkylphenyl)-1,1-biphenyl4,4′-diamine wherein alkyl is selected from the group consisting of methyl, ethyl, propyl, butyl, hexyl, and the like; N,N′-diphenyl-N,N′-bis(halophenyl)-1,1′-biphenyl4,4′-diamine wherein the halo substituent is a chloro substituent; N,N′-bis(4-butylphenyl)-N,N′-di-p-tolyl-[p-terphenyl]4,4″-diamine, N,N′-bis(4-butylphenyl)-N,N′-di-m-tolyl-[p-terphenyl]4,4″-diamine, N, N′-bis(4-butylphenyl)-N,N′-di-o-tolyl-[p-terphenyl]4,4″-diamine, N,N′-bis(4-butylphenyl)-N,N′-bis-(4-isopropylphenyl)-[p-terphenyl]4,4″-diamine, N,N′-bis(4-butylphenyl)-N,N′-bis-(2-ethyl-6-methylphenyl)-[p-terphenyl]4,4″-diamine, N,N′-bis(4-butylphenyl)-N,N′-bis-(2,5-dimethylphenyl)-[p-terphenyl]4,4″-diamine, N,N′-diphenyl-N,N′-bis(3-chlorophenyl)-[p-terphenyl]4,4″-diamine and the like and optionally mixtures thereof. Other known charge transport layer molecules can be selected, reference for example, U.S. Pat. Nos. 4,921,773 and 4,464,450, the disclosures of which are totally incorporated herein by reference. In embodiments, the charge transport layer may comprise aryl amine mixtures.
Examples of components or materials optionally incorporated into the charge transport layers or at least one charge transport layer to, for example, enable improved lateral charge migration (LCM) resistance include hindered phenolic antioxidants such as tetrakis methylene(3,5-di-tert-butyl-4-hydroxy hydrocinnamate) methane (IRGANOX® 1010, available from Ciba Specialty Chemical), butylated hydroxytoluene (BHT), and other hindered phenolic antioxidants including SUMILIZER™ BHT-R, MDP-S, BBM-S, WX-R, NW, BP-76, BP-101, GA-80, GM and GS (available from Sumitomo Chemical Co., Ltd.), IRGANOX® 1035, 1076, 1098, 1135, 1141, 1222, 1330, 1425WL, 1520L, 245, 259, 3114, 3790, 5057 and 565 (available from Ciba Specialties Chemicals), and ADEKA STAB™ AO-20, AO-30, AO-40, AO-50, AO-60, AO-70, AO-80 and AO-330 (available from Asahi Denka Co., Ltd.); hindered amine antioxidants such as SANOL™ LS-2626, LS-765, LS-770 and LS-744 (available from SNKYO CO., Ltd.), TINUVIN® 144 and 622LD (available from Ciba Specialties Chemicals), MARK™ LA57, LA67, LA62, LA68 and LA63 (available from Asahi Denka Co., Ltd.), and SUMILIZER® TPS (available from Sumitomo Chemical Co., Ltd.); thioether antioxidants such as SUMILIZER® TP-D (available from Sumitomo Chemical Co., Ltd); phosphite antioxidants such as MARK™ 2112, PEP-8, PEP-24G, PEP-36, 329K and HP-10 (available from Asahi Denka Co., Ltd.); other molecules such as bis(4-diethylamino-2-methylphenyl) phenylmethane (BDETPM), bis-[2-methyl-4-(N-2-hydroxyethyl-N-ethyl-aminophenyl)]-phenylmethane (DHTPM), and the like. The weight percent of the antioxidant in at least one of the charge transport layer is from about 0 to about 20, from about 1 to about 10, or from about 3 to about 8 weight percent.
The charge transport layer or layers, and more specifically, a first charge transport in contact with the charge generating layer, and thereover a top or second charge transport overcoating layer may comprise the illustrated charge transporting small molecules dissolved or molecularly dispersed in a film forming electrically inert polymer such as a polycarbonate. In embodiments, dissolved refers, for example, to forming a solution in which the small molecule is dissolved in the polymer to form a homogeneous phase; and molecularly dispersed in embodiments refers, for example, to charge transporting molecules dispersed in the polymer, the small molecules being dispersed in the polymer on a molecular scale.
The charge transport layer should be an insulator to the extent that the electrostatic charge placed on the hole transport layer is not conducted in the absence of illumination at a rate sufficient to prevent formation and retention of an electrostatic latent image thereon. In general, the ratio of the thickness of the charge transport layer to the charge generating layer can be maintained from about 2:1 to 200:1, and in some instances as great as 400:1. The charge transport layer is substantially nonabsorbing to visible light or radiation in the region of intended use, but is electrically “active” in that it allows the injection of photogenerated holes from the photoconductive layer, that is the charge generating layer, and allows these holes to be transported through itself to selectively discharge a surface charge on the surface of the active layer.
An adhesive layer may optionally be applied such as to the hole blocking layer. The adhesive layer may comprise any suitable material, for example, any suitable film forming polymer. Typical adhesive layer materials include for example, but are not limited to, copolyester resins, polyarylates, polyurethanes, blends of resins, and the like. Any suitable solvent may be selected in embodiments to form an adhesive layer coating solution. Typical solvents include, but are not limited to, for example, tetrahydrofuran, toluene, hexane, cyclohexane, cyclohexanone, methylene chloride, 1,1,2-trichloroethane, monochlorobenzene, and mixtures thereof, and the like.
In embodiments, a photoconductive imaging member further includes an adhesive layer of a polyester with an M w of about 75,000, and an M n of about 40,000.
The charge generating layer is comprised in embodiments of metal phthalocyanines, metal free phthalocyanines, rylenes, perylenes, hydroxygallium phthalocyanines, chlorogallium phthalocyanines, titanyl phthalocyanines, vanadyl phthalocyanines, selenium, selenium alloys, trigonal selenium, and the like, and mixtures thereof. In other embodiments, the charge generating layer is comprised of titanyl phthalocyanines, perylenes, or hydroxygallium phthalocyanines. In yet another embodiment, the charge generating layer is comprised of Type V hydroxygallium phthalocyanine.
The charge generating layer, which can be comprised of the components indicated herein, such as hydroxychlorogallium phthalocyanine, is in embodiments comprised of, for example,-about 50 weight percent of the hydroxygallium or other suitable photogenerating pigment, and about 50 weight percent of a resin binder like polystyrene/polyvinylpyridine. The charge generating layer can contain known photogenerating pigments, such as metal phthalocyanines, metal free phthalocyanines, hydroxygallium phthalocyanines, rylenes, perylenes, especially bis(benzimidazo)perylene, titanyl phthalocyanines, and the like, and more specifically, vanadyl phthalocyanines, Type V chlorohydroxygallium phthalocyanines, and inorganic components, such as selenium, especially trigonal selenium. The photogenerating pigment can be dispersed in a resin binder similar to the resin binders selected for the charge transport layer, or alternatively no resin binder is needed. Photogenerating pigments can be selected for the charge generating layer in embodiments for example of an amount of from about 10 percent by weight to about 95 percent by weight dispersed in a resinous binder.
Generally, the thickness of the charge generating layer depends on a number of factors, including the thicknesses of the other layers and the amount of photogenerator material contained in the charge generating layers. Accordingly, this layer can be of a thickness of, for example, from about 0.05 micron to about 15 microns, or from about 0.25 micron to about 2 microns when, for example, the photogenerator compositions are present in an amount of from about 30 to about 75 percent by volume. The maximum thickness of this layer in embodiments is dependent primarily upon factors, such as photosensitivity, electrical properties and mechanical considerations. The charge generating layer binder resin present in various suitable amounts, for example from about 1 to about 50 or from about 1 to about 10 weight percent, may be selected from a number of known polymers, such as poly(vinyl butyral), poly(vinyl carbazole), polyesters, polycarbonates, poly(vinyl chloride), polyacrylates and methacrylates, copolymers of vinyl chloride and vinyl acetate, phenoxy resins, polyurethanes, poly(vinyl alcohol), polyacrylonitrile, polystyrene, and the like. It is desirable to select a coating solvent that does not substantially disturb or adversely affect the other previously coated layers of the device. Examples of solvents that can be selected for use as coating solvents for the charge generating layers are ketones, alcohols, aromatic hydrocarbons, halogenated aliphatic hydrocarbons, ethers, amines, amides, esters, and the like. Specific examples are cyclohexanone, acetone, methyl ethyl ketone, methanol, ethanol, butanol, amyl alcohol, toluene, xylene, chlorobenzene, carbon tetrachloride, chloroform, methylene chloride, trichloroethylene, tetrahydrofuran, dioxane, diethyl ether, dimethyl formamide, dimethyl acetamide, butyl acetate, ethyl acetate, methoxyethyl acetate, and the like.
Illustrative examples of polymeric binder materials that can be selected for the charge generating layer are as indicated herein, and include those polymers as disclosed in U.S. Pat. No. 3,121,006, the disclosure of which is totally incorporated herein by reference; phenolic resins as illustrated in the appropriate copending applications recited herein, the disclosures of which are totally incorporated herein by reference. In general, the effective amount of polymer binder that is utilized in the charge generating layer ranges from about 0 to about 95 percent by weight, or from about 25 to about 60 percent by weight of the charge generating layer.
In embodiments, the at least one charge transport layer comprises an antioxidant optionally comprised of, for example, a hindered phenol or a hindered amine.
Examples of binder materials for the transport layers include components, such as those described in U.S. Pat. No. 3,121,006, the disclosure of which is totally incorporated herein by reference. Specific examples of polymer binder materials include polycarbonates, polyarylates, acrylate polymers, vinyl polymers, cellulose polymers, polyesters, polysiloxanes, polyamides, polyurethanes and epoxies, and block, random or alternating copolymers thereof. In embodiments, electrically inactive binders are selected comprised of polycarbonate resins having a molecular weight of from about 20,000 to about 100,000 or from about 50,000 to about 100,000. Generally, the transport layer contains from about 10 to about 75 percent by weight of the charge transport material or from about 35 percent to about 50 percent of this material.
In embodiments, the at least one charge transport layer comprises from about 1 to about 7 layers. For example, in embodiments, the at least one charge transport layer comprises a top charge transport layer and a bottom charge transport layer, wherein the bottom layer is situated between the charge generation layer and the top layer.
Also, included herein are methods of imaging and printing with the photoresponsive devices illustrated herein. These methods generally involve the formation of an electrostatic latent image on the imaging member, followed by developing the image with a toner composition comprised, for example, of thermoplastic resin, colorant, such as pigment, charge additive, and surface additives, reference U.S. Pat. Nos. 4,560,635; 4,298,697 and 4,338,390, the disclosures of which are totally incorporated herein by reference, subsequently transferring the image to a suitable substrate, and permanently affixing the image thereto. In those environments wherein the device is to be used in a printing mode, the imaging method involves the same steps with the exception that the exposure step can be accomplished with a laser device or image bar.
Various exemplary embodiments encompassed herein include a method of imaging which includes generating an electrostatic latent image on an imaging member, developing a latent image, and transferring the developed electrostatic image to a suitable substrate.
In a selected embodiment, an image forming apparatus for forming images on a recording medium comprising: a) an imaging member having a charge retentive-surface for receiving an electrostatic latent image thereon, wherein the imaging member comprises a substrate, a charge generating layer disposed on the substrate, at least one charge transport layer disposed on the charge generating layer, and an anticurl back coating disposed on the substrate on a side opposite to the charge transport layer, the anticurl back coating comprising a polyol ester or polyol amide; b) a development component for applying a developer material to the charge-retentive surface to develop the electrostatic latent image to form a developed image on the charge-retentive surface; c) a transfer component for transferring the developed image from the charge-retentive surface to a copy substrate; and d) a fusing component for fusing the developed image to the copy substrate.
While the description above refers to particular embodiments, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of embodiments herein.
The presently disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of embodiments being indicated by the appended claims rather than the foregoing description. All changes that come within the meaning of and range of equivalency of the claims are intended to be embraced therein.
EXAMPLES
The examples set forth herein below and are illustrative of different compositions and conditions that can be used in practicing the present embodiments. All proportions are by weight unless otherwise indicated. It will be apparent, however, that the present embodiments can be practiced with many types of compositions and can have many different uses in accordance with the disclosure above and as pointed out hereinafter.
Comparative Example 1
A controlled anticurl back coating solution was prepared by introducing into an amber glass bottle in a weight ratio of 0.08:0.92 VITEL® 2200 (used to be VPE-200), a copolyester of iso/tere-phthalic acid, dimethylpropanediol and ethanediol having a melting point from about 302 to about 320° C., commercially available from Shell Oil Company, Houston, Tex., and MAKROLON® 5705, a known polycarbonate resin having a molecular weight average of from about 50,000 to about 100,000, commercially available from Farbenfabriken Bayer A.G. The resulting mixture was then dissolved in methylene chloride to form a solution containing 9 percent by weight solids. This solution was applied on the back of the substrate, a biaxially oriented polyethylene naphthalate substrate (KALEDEX® 2000) having a thickness of 3.5 mils, to form a coating of the anticurl back coating layer that upon drying (120° C. for 1 minute) had a thickness of 17.4 microns. During this coating process the humidity was equal to or less than 15 percent.
Example 1
A disclosed anticurl back coating solution was prepared by introducing into an amber glass bottle in a weight ratio of 0.02:0.0784:0.9016 HOSTASTAT™ FE20liq (glycerol fatty acid ester), available from Clariant Corporation, Charlotte, NC, VITEL® 2200 (used to be VPE-200), a copolyester of iso/tere-phthalic acid, dimethylpropanediol and ethanediol having a melting point from about 302 to about 320° C., commercially available from Shell Oil Company, Houston, Tex., and MAKROLON® 5705, a known polycarbonate resin having a molecular weight average of from about 50,000 to about 100,000, commercially available from Farbenfabriken Bayer A.G. The resulting mixture was then dissolved in methylene chloride to form a solution containing 9 percent by weight solids. This solution was applied on the back of the substrate, a biaxially oriented polyethylene naphthalate substrate (KALEDEX™ 2000) having a thickness of 3.5 mils, to form a coating of the anticurl back coating layer that upon drying (120° C. for 1 minute) had a thickness of 17.4 microns. During this coating process the humidity was equal to or less than 15 percent.
Example 2
A disclosed anticurl back coating dispersion was prepared by introducing into an amber glass bottle in a weight ratio of 0.02:0.09:0.0712:0.8188 HOSTASTAT™ FE20liq (glycerol fatty acid ester), available from Clariant Corporation, Charlotte, N.C., PTFE POLYFLON™ L-2 microparticle, commercially available from Daikin Industries, VITEL® 2200 (used to be VPE-200), a copolyester of iso/tere-phthalic acid, dimethylpropanediol and ethanediol having a melting point from about 302 to about 320° C., commercially available from Shell Oil Company, Houston, Tex., and MAKROLON® 5705, a known polycarbonate resin having a molecular weight average of from about 50,000 to about 100,000, commercially available from Farbenfabriken Bayer A.G. The resulting mixture was then dissolved and dispersed in methylene chloride via mechanical shear to form a dispersion containing 9.7 percent by weight solids. This dispersion was applied on the back of the substrate, a biaxially oriented polyethylene naphthalate substrate (KALEDEX™ 2000) having a thickness of 3.5 mils, to form a coating of the anticurl back coating layer that upon drying (120° C. for 1 minute) had a thickness of 18.7 microns. During this coating process the humidity was equal to or less than 15 percent.
Example 3
A disclosed anticurl back coating solution was prepared by introducing into an amber glass bottle in a weight ratio of 0.04:0.0768:0.8832 NINOL® C-5 (formerly AMIDOX® C-5, polyethylene glycol cocamide), available from STEPAN Company, Northfield, Ill., VITEL® 2200 (used to be VPE-200), a copolyester of iso/tere-phthalic acid, dimethylpropanediol and ethanediol having a melting point from about 302 to about 320° C., commercially available from Shell Oil Company, Houston, Tex., and MAKROLON® 5705, a known polycarbonate resin having a molecular weight average of from about 50,000 to about 100,000, commercially available from Farbenfabriken Bayer A.G. The resulting mixture was then dissolved in methylene chloride to form a solution containing 9 percent by weight solids. This solution was applied on the back of the substrate, a biaxially oriented polyethylene naphthalate substrate (KALEDEX™ 2000) having a thickness of 3.5 mils, to form a coating of the anticurl back coating layer that upon drying (120° C. for 1 minute) had a thickness of 17.4 microns. During this coating process the humidity was equal to or less than 15 percent.
Example 4
A disclosed anticurl back coating solution was prepared by introducing into an amber glass bottle in a weight ratio of 0.06:0.0752:0.8648 STEPAN™ PEG 400 DO (polyethylene glycol dioleate), available from STEPAN Company, Northfield, Ill., VITEL® 2200 (used to be VPE-200), a copolyester of iso/tere-phthalic acid, dimethylpropanediol and ethanediol having a melting point from about 302 to about 320° C., commercially available from Shell Oil Company, Houston, Tex., and MAKROLON® 5705, a known polycarbonate resin having a molecular weight average of from about 50,000 to about 100,000, commercially available from Farbenfabriken Bayer A.G. The resulting mixture was then dissolved in methylene chloride to form a solution containing 9 percent by weight solids. This solution was applied on the back of the substrate, a biaxially oriented polyethylene naphthalate substrate (KALEDEX™ 2000) having a thickness of 3.5 mils, to form a coating of the anticurl back coating layer that upon drying (120° C. for 1 minute) had a thickness of 17.4 microns. During this coating process the humidity was equal to or less than 15 percent.
Five photoreceptor devices were prepared with the above anticurl back coating solutions/dispersion, respectively to form an ACBC layer on the back side of the substrate. On the front side of the substrate, same-photoactive layers were prepared for all the examples as follows:
A 0.02 micron thick titanium layer was coated on a biaxially oriented polyethylene naphthalate substrate (KALEDEX™ 2000) having a thickness of 3.5 mils, and applying thereon, with a gravure applicator, a solution containing 50 grams of 3-amino-propyltriethoxysilane, 41.2 grams of water, 15 grams of acetic acid, 684.8 grams of denatured alcohol, and 200 grams of heptane. This layer was then dried for about 5 minutes at 135° C. in the forced air dryer of the coater. The resulting blocking layer had a dry thickness of 500 Angstroms. An adhesive layer was then prepared by applying a wet coating over the blocking layer using a gravure applicator, and which adhesive contains 0.2 percent by weight based on the total weight of the solution of copolyester adhesive (ARDEL D100™ available from Toyota Hsutsu Inc.) in a 60:30:10 volume ratio mixture of tetrahydrofuran/monochlorobenzene/methylene chloride. The adhesive layer was then dried for about 5 minutes at 135° C. in the forced air dryer of the coater. The resulting adhesive layer had a dry thickness of 200 Angstroms.
A charge generating layer dispersion was prepared by introducing 0.45 grams of the known polycarbonate LUPILON 200™ (PCZ-200) or POLYCARBONATE Z™, weight average molecular weight of 20,000, available from Mitsubishi Gas Chemical Corporation, and 50 milliliters of tetrahydrofuran into a 4 ounce glass bottle. To this solution were added 2.4 grams of hydroxygallium phthalocyanine (Type V) and 300 grams of ⅛ inch (3.2 millimeters) diameter stainless steel shot. This mixture was then placed on a ball mill for 8 hours. Subsequently, 2.25 grams of PCZ-200 were dissolved in 46.1 grams of tetrahydrofuran, and added to the hydroxygallium phthalocyanine dispersion. This slurry was then placed on a shaker for 10 minutes. The resulting dispersion was, thereafter, applied to the above adhesive interface with a Bird applicator to form a charge generating layer having a wet thickness of 0.25 mil. A strip about 10 millimeters wide along one edge of the substrate web bearing the blocking layer and the adhesive layer was deliberately left uncoated by any of the charge generating layer material to facilitate adequate electrical contact by the ground strip layer that was applied later. The charge generating layer was dried at 120° C. for 1 minute in a forced air oven to form a dry charge generating layer having a thickness of 0.4 microns.
The resulting imaging member web was then overcoated with a two-layer charge transport layer. Specifically, the charge generating layer was overcoated with a charge transport layer (the bottom layer) in contact with the charge generating layer. The bottom layer of the charge transport layer was prepared by introducing into an amber glass bottle in a weight ratio of 1:1 N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl4,4′-diamine, and MAKROLON 5705®, a known polycarbonate resin having a molecular weight average of from about 50,000 to about 100,000, commercially available from Farbenfabriken Bayer A.G. The resulting mixture was then dissolved in methylene chloride to form a solution containing 15 percent by weight solids. This solution was applied on the charge generating layer to form the bottom layer coating that upon drying (120° C. for 1 minute) had a thickness of 14.5 microns. During this coating process, the humidity was equal to or less than 15 percent.
The bottom layer of the charge transport layer was then overcoated with a top layer. The charge transport layer solution of the top layer was prepared as described above for the bottom layer. This solution was applied on the bottom layer of the charge transport layer to form a coating that upon drying (120° C. for 1 minute) had a thickness of 14.5 microns. During this coating process the humidity was equal to or less than 15 percent.
The above prepared photoreceptor devices were flat. The ACBC coatings for all the devices were defects free without any bubbles, which indicated excellent adhesions between the ACBC layer and the substrate. Incorporation of polyol ester or polyol amide into ACBC did not adversely affect coating quality of the layer and adhesion between the layer and the substrate.
The ACBC layers were tested for surface resistivity with a Hewlett Packard 4339A High Resistance Meter using a Hewlett Packard HP 16008B Resistivity Cell, 25 mm diameter electrode, 500 volt excitation, 5.0 Kilograms electrode pressure. The results are summarized in Table 1.
TABLE 1 Surface resistivity (ohm/cm 2 ) Comparative Example 1 1.8 × 10 17 Example 1 3.9 × 10 11 Example 2 1.3 × 10 12 Example 3 1.9 × 10 15 Example 4 9.1 × 10 16
Incorporation of polyol ester or polyol armide into ACBC increased surface conductivity by from about 50 to about 1,000,000 times, which would help reduce or substantially eliminates, electrostatic charge buildup caused by friction with the backer plates and rollers. Incorporation of polyol ester or polyol amide into ACBC would also help reduce friction and improve wear resistance caused by contact with the backer plates and rollers.
While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.
|
The presently disclosed embodiments relate in general to electrophotographic imaging members, such as layered photoreceptor structures, and processes for making and using the same. More particularly, the embodiments pertain to the incorporation of polyol esters and/or amides in the anticurl back coating to reduce or eliminate static charge buildup in the imaging member and to improve image quality.
| 6
|
FIELD OF THE INVENTION
The present invention pertains generally to stitch-forming machines and more particularly to a thread monitor for indicating missed stitches.
BACKGROUND OF THE INVENTION
A thread monitor, known from U.S. Pat. No. 4,170,951, is arranged on a sewing machine in the path of the needle thread and is provided with a transducer with a spring clip, to which a wire strain gauge element, hereinafter called a WSG element, is fastened. The WSG element produces an electrical voltage that is proportional to its mechanical deformation caused by the deflecting movement of the spring clip. The electrical voltage is fed into an evaluating electronic unit following the transducer.
In the course of a stitch, a first, lower tension level is produced during the expansion of the needle thread loop, and a second, higher tension level is generated during the knotting. To detect missed stitches, the tension levels are monitored in measuring windows, whose positioning and size are predetermined by two signal generators that monitor the position of the arm shaft.
A plurality of actual values are determined from the lower tension level, and compared with a threshold value, whose value depends on the maximum of the higher tension level generated during the preceding stitch. If all actual values are below this threshold value, a warning signal is sent by the evaluating electronic unit to indicate a missed stitch.
Since the maximum of the higher tension level may differ from the corresponding value of the preceding stitch during each stitch, and the threshold value depends on this maximum, the threshold value is to be determined anew for each stitch. Such a signal evaluation is problematic especially at high sewing speeds and requires the use of an expensive evaluating electronic unit.
Due to its dependence on the preceding higher tension level, the threshold value cannot be formed during the first stitch performed with ordinary tension after start-up of the sewing machine, which causes a delay in the monitoring process. To prevent this disadvantage, additional control elements not disclosed in U.S. Pat. No. 4,170,951 are necessary. This increases the circuit complexity of the evaluating electronic unit, which is suitable exclusively for indicating missed stitches caused by lack of expansion of the needle thread loop.
SUMMARY AND OBJECTS OF THE INVENTION
It is a primary object of the present invention to design a control device of a stitch-forming machine equipped with a transducer, so that the control device is able to evaluate the measured values sent by the transducer, at low circuit complexity, beginning from the first stitch performed with ordinary tension to detect a majority of different missed stitches as well as thread disturbances on the thread being monitored and on the threads to be connected to this by stitch formation.
According to the invention, a stitch forming machine is provided including a transducer for determining the tension present in a thread, wherein the thread tension assumes a higher value during stitch formation and the transducer provides a signal representing the tension level. Control means are provided for evaluating the signal corresponding to the tension level. The control means includes a comparator device for comparing a peak of the signal representing the tension level, which peak can be used to detect a malfunction, with a limit signal, corresponding to a limit tension. The comparator sends a signal to a switching device when a signal peak drops below the limit signal. The switching device may be connected to a shut-off device of the drive motor of the machine as well as one or more display elements. In this way, the machine may be stopped and the display element associated with a limit tension, below which the tension dropped by a switching device.
According to another aspect of the invention, a stitch forming a machine is provided included a transducer for determining the tension in a thread and for outputting a signal representing the tension of the thread. Control means are provided for evaluating the signal representing the tension of the thread, the tension of the thread assuming higher values while stitches are formed. Control means are provided for evaluating the thread tension based on the stitch formation stage. The control means includes a comparator device for comparing a peak in the transducer signal corresponding to a peak in the tension level, the peak being used to detect a malfunction, with a predeterminable, common limit signal representing a common limit tension. The comparator provides a signal for energizing a switch depending upon a stitch formation phase associated with a signal peak which drops below a limit signal. The switching device is connected to a shut-off device of a drive motor of the machine or a plurality of display elements so that the machine can be stopped and the display element associated with the phase of stitch formation can be switched by the switching device.
The control device according to the present invention makes it possible to detect a plurality of different malfunctions on the thread, such as different types of missed stitches or the break of the needle thread and--in the case of double lockstitch machines as well as multi-thread chain stitch machines--the break of the hook or looper thread by means of a single transducer, because such a malfunction is positively demonstrable by the change in the value of the tension peak associated with this.
Monitoring the tension peaks by a comparator device, according to the invention, is advantageous if at least one of the tension levels has a plurality of tension peaks. Since not every of these voltages peaks is usually suitable for detecting a malfunction, only those peaks from which a malfunction is recognizable are monitored. This makes it possible to reduce the monitoring time to a minimum.
Since a plurality of different malfunctions can be recognized by monitoring the tension peaks, it is advantageous to stop the PG,7 machine in the case of a malfunction and to indicate the malfunction by a separate display element associated with this. The display element, which can be switched via the switching device, may be designed as an optical or acoustic warning device.
By presetting the limit tension associated with the actual tension peak according to one aspect of the invention or the limit tension that is uniform for all tension peaks according to another aspect of the invention, it is ensured that the tension peaks can be monitored even during the first stitch performed with ordinary tension, because the corresponding limit voltage can immediately be associated with each tension peak by the comparator device.
By presetting a limit tension adjusted to the respective tension peak by the comparator device, the tension value below which a malfunction is recognizable can be individually adjusted to the maximum of the tension peak, so that a malfunction can be indicated as quickly as possible after it appears, but variations in the values of the voltage peaks that are caused by the sewing technique bring about no switching process.
In the design of the comparator device according to another aspect of the invention, a common limit tension is set for all tension peaks regardless of their values in order to simplify the circuit. The phase of stitch formation of the machine, which is sent as a signal to the comparator device, is needed as a second unit of information. The reduction of the voltage peak below the limit tension is used to detect a malfunction here, while the nature of the malfunction can be determined from the phase of stitch formation associated with the tension peak.
A particularly advantageous application of the control device according to the present invention is disclosed in which different missed stitches caused by a pick-up or stitch-down error, as well as a break or end of the needle thread and hook or looper thread can be recognized by monitoring the tension peaks that indicate the corresponding information.
Measurement experiments have shown that such parameters as the speed of sewing, stitch length, and the thread properties cause only insignificant changes in the maximum of the voltage peaks, whereas the setting of the tensioning device substantially affects it. To rule out disadvantages during thread monitoring in the case of a changed setting of the tensioning device, the limit tension and consequently also the response threshold of the comparator device are adjusted to the thread voltage set by the adjusting device.
Due to the measure of providing a spring member that can be deflected by the tensioned thread with a sensor device responsive to the proportioned deflection wherein the spring element tapers towards its free end beginning from its point of clamping, the spring element has the lowest possible weight at a predetermined bending strength. As a result, the effect of the natural oscillations of the spring element on the values of the thread tension sent to the control device will be negligible even at high sewing speeds.
The measure of fastening the transducer on the machine via a damping element, reduces the oscillations transmitted from the machine to the transducer to a negligible level, so that the values of the thread tension are not distorted by these oscillations.
The measure of providing the transducer arranged immediately downstream of a tensioning device, with respect to a direction of pull, leads to the variations in tension brought about by stitch formation being reduced to a minimum, which might cause distortion of the thread tension transmitted to the control device.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 in a side partially sectional view of a sewing machine with a thread monitor equipped with a transducer according to the invention;
FIG. 2 is a partially sectional view showing the transducer according to FIG. 1 on a larger scale;
FIG. 3 is a circuit diagram showing a simplified control device according to the invention;
FIGS. 4a through 4g are diagrams representing the following processes relative to one stitch:
FIG. 4a: thread voltage (U F ) without malfunction,
FIG. 4b: thread voltage (U F ) during a pick-up error or disturbance on the needle thread,
FIG. 4c: thread voltage (U F ) during a stitch-down error or a disturbance on the hook or looper thread,
FIG. 4d: comparator voltage (U K ) without malfunction,
FIG. 4e: comparator voltage (U K ) during a malfunction according to FIG. 4b,
FIG. 4f: comparator voltage (U K ) during a malfunction according to FIG. 4c,
FIG. 4g: impulses (I) of a position transmitter;
FIG. 5 is a partially sectional view showing a second embodiment of the transducer on a larger scale;
FIG. 6 is a circuit diagram showing a simplified second embodiment of the control device; and
FIG. 7 is a diagram showing the thread voltage (U F ) without malfunction according to the second embodiment of the control device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A tensioning device 2 for the needle thread coming from a thread reserve (not shown) is arranged on the stand 1 of the double-thread chainstitch sewing machine shown in FIG. 1. A transducer 3, which is fastened to the sewing machine via a damping element 4 (FIG. 2) made of, e.g., rubber, is provided behind the tensioning device 2 in the direction of thread pull. The transducer 3 has a bending bar 5, whose width is reduced toward the free end beginning from the clamping point. At its free end, the bending bar 5 is designed on the underside with a needle thread-receiving eye 6 on it.
Wire strain gauge elements, hereinafter called WSG elements 7, are provided to receive the tension of the needle thread. A first WSG element 7 is fastened on the top side and a second WSG element 8 on the underside of the bending bar 5 close to the point of clamping of the bending bar.
The WSG elements 7 and 8 are connected to a power source (FIG. 3) and are connected to form a half bridge 9 which is connected to an amplifier 10. The output of the amplifier 10 is connected to a voltmeter 11 with a display unit 12 and to a comparator 13 with an adjusting device 14 serving to set its switching threshold.
The output of the comparator 13 is connected to one input of AND elements 15 and 16 each, whose second input is connected to a position transmitter 18 that counts the revolutions of the main shaft 17. This position transmitter 18 has a photodiode 19, which is connected to the positive pole of a stabilized power source, is grounded via a resistor 20, and has a photodetector 21, which is designed as a phototransistor, is also connected to the positive pole, and is grounded via a resistor 22. The position transmitter 18 is also provided with a photodiode 23, which is connected to the positive pole of the power source, is grounded via a resistor 24, as well as with a photodetector 25, which is also connected to the positive pole, is designed as a phototransistor, and is grounded via a resistor 26. A disk 27, which is arranged nonrotatably on the main shaft 17, is provided between the photodiodes 19 and 23 and the photodetector 21 and 25; the disk 27 has--in the light path between the photodiode 19 and the photodetector 21--a first opening 28 and, on another radius, in the light path between the photodiode 23 and the photodetector 25, a second opening 29 for passage of the light beams. During each passage through the opening 28, an impulse is sent to the AND element 15, and during each passage through the opening 29, an impulse is sent to the AND element 16, and the AND element 16 is energized for a period corresponding to rotation of the disk 27 through 180° after the AND element 15.
The output of the AND element 15 is connected to the setting input S of a flip-flop memory 30, and that of the AND element 16 is connected to the setting input S of a flip-flop memory 31. The AND elements 15 and 16 form, together with the memories 30 and 31, a switching circuit 32.
The output Q of the memory 30 is connected to a display element 33, which is grounded via a resistor 34, while a display element 35, which is grounded via a resistor 36, is connected to the output Q of the memory 31. In addition, a switch 37, which is connected to a shut-off device 38 of a drive motor 39, is connected to the outputs Q of the memories 30 and 31. The drive motor 39 drives said main shaft 17 via a toothed belt.
The elements 10 through 37 form a control device 40, which is provided for evaluating the thread voltage (U F ) measured by the transducer 3.
Behind the transducer 3 in the direction of thread pull (FIG. 1), a first thread guide element 42 is fastened on the sewing machine, and a second thread guide element 44 is fastened on the head 43. The needle thread is fed by the thread guide element 44 to the needle 48 via a thread lever 45 and further thread guide elements (not shown), as well as an eye 47 provided on a needle bar 46. A chain stitch looper 51 is arranged beneath the needle plate 50 accommodated in the base plate 49. The looper thread is fed to the looper 52 via a tensioning device 52 fastened on the stand 1 as well as thread guide elements (not shown).
The elements 45, 46, 48, and 51 will hereinafter be called stitch-forming elements 53.
The device operates as follows:
During sewing, the needle thread and the looper thread are pulled off from the thread reserve, while the tension of the threads varies depending on the movement of the stitch-forming elements 53. Since the needle thread and the looper thread are to be linked with one another by the stitch formation in terms of tension, one transducer 3 in the path of the needle thread is sufficient to determine the changes in the thread voltage (U F ) formed from the voltages of all thread.
FIG. 4a shows the changes in the thread tension (U F ) during trouble-free stitch formation during one stitch.
The first tension level (U p1 ) exceeding the normal tension (U N ) is formed when the loop of the needle thread is caught and expanded by the looper 51 after the needle 48 has passed through a material being sewn. The first tension level (U p1 ) reaches its tension peak (U 1 ) at the time (t 1 ).
The second tension level (U p2 ) is formed when the thread lever 45 performs an upward movement to tighten the loop formed by the needle thread and the looper thread. The tension level (U p2 ) has two tension peaks (U 2 ,1 and U 2 ,2) at the times (t 2 and t 3 ), and the value of the first tension peak (U 2 ,1) exceeds that of the second tension peak (U 2 ,2).
When the looper 51 misses the needle thread loop, a pick-up error occurs. In the case of such an error or break of the needle thread behind the tensioning device 2 in the direction of thread pull, the thread voltage (U F ) changes according to FIG. 4b. The first tension level (U p1 ) assumes the value of the normal tension (U N ) or even drops below this value, while the second tension level (U p2 ) is formed only with one tension peak (U 2 ).
Should said needle 48 miss the loop formed by the looper thread after passing through the material being sewn, a stitch-down error occurs. Like the break of the looper thread behind said tensioning device 52 in the direction of thread pull, this is indicated by a change in the thread tension (U F ) according to FIG. 4c). Just like the first tension peak (U 2 ,1) of the second tension level (U p2 ), the first tension level (U p1 ) remains nearly unchanged, whereas the value of the second tension peak (U 2 ,2) is greatly reduced.
The transducer 3 (FIG. 1) is arranged between the tensioning device 2 and the thread guide element 42 so that the needle thread is deflected while passing through the eye 6. As a result, a force perpendicular to the direction of extension of the bending bar 5, by which the bending bar is deflected in the downward direction, is generated. As a consequence of this deflection, which is proportional to the thread tension (U F ), the WSG element 7 is tensioned on the top side of the bending bar 5, and the WSG element 8 on its underside is compressed, so that the electrical resistance of both WSG elements 7 and 8 will change. As a result, a differential tension (U D ) is formed, which is proportional to the deflection of said bending bar 5 and whose changes during one stitch correspond to those of the thread tension (U F ).
After amplification by the amplifier 10 (FIG. 3), the differential voltage (U D ) is sent to the voltmeter 11, which displays its value, as well as to the comparator 13. Depending on the setting of the tensioning device 2, the switching threshold of the comparator 13 can be adjusted by means of the adjusting device 14, so that its sensitivity is adjusted to the tension of the needle thread. The switching threshold is selected so that one of the tension peaks (U 1 , U 2 ,2) will drop below it only when malfunction, such as a missed step or thread break, has occurred. The tension corresponding to the switching threshold will hereinafter be called the limit tension corresponding to a limit voltage (U G ), which is shown in FIGS. 4a through 4c.
The comparator 13 is turned on as long as the differential voltage (U D ) present at its input is lower than the limit voltage (U G ), and is turned off as soon as the differential voltage (U D ) assumes or exceeds the value of the limit voltage (U G ) FIG. 4d shows the changes in the output voltage (U K ) of said comparator (13) as a function of the differential voltage (U D ) according to FIG. 4a, while the changes in the output voltage (U K ) according to FIG. 4e are associated with those of the differential voltage (U D ) according to FIG. 4b, and the changes in the output voltage (U K ) according to FIG. 4f are associated with those of the differential voltage (U D ) according to FIG. 4c.
As long as no malfunction has occurred, the comparator output voltage (U K ) is present at the input of the AND elements 15 and 16 when none of the impulses (I 1 or I 2 ) shown in FIG. 4g, which are sent by the position transmitter 18, arrives. As a result, no signal is able to leave the AND elements 15 and 16.
In the case of the malfunction according to FIG. 4b, the impulse (I 1 ) of the position transmitter 18 arrives at time (t 1 ) from the photodetector 21 to one input of the AND element 15 when the comparator voltage output (U K ) is present at its other input. A signal is then sent from the output of the AND element 15 to the setting input S of the memory 30. The signal causes the memory 30 to turn on, via its output Q, the display element 33, which will display a pick-up error or the break of the needle thread. With the switch 37 closed the output Q of the memory 30 activates at the same time the shutoff device 38, which, depending on the design, turns off the drive motor 39 immediately, or prevents it from restarting after the next stoppage.
After a resetting switch (not shown) has been activated, an electrical impulse is sent in a suitable manner to the resetting input (R) of the memory 30, so that this will turn off the display element 33 and release the drive motor 39.
In the case of a malfunction according to FIG. 4c, said photodetector 25 of the position transmitter 18 sends an impulse (I 2 ) at time (t 3 ) to one input of the AND element 16, while the comparator voltage (U K ) is present at its other input. As a result, the AND element 16 is connected through, and sends from its output a signal to the setting input S of the memory 31, so that this will turn on, via its output Q, the display element 35, which will display a stitch-down error or a break of the looper thread. With the switch 37 closed, the output Q of the memory 31 at the same time activates, like that of the memory 30, the shutoff device 38 of the drive motor 39. The display element 35 is turned off by an electrical signal sent to the resetting input R of the memory 31, and the drive motor 39 is released.
FIG. 5 shows a second embodiment of the transducer 3. A permanent magnet 54 is fastened on the top side of the bending bar 5 at its free end. A Hall sensor 56 is fastened at the free end of a bracket 55, facing the permanent magnet 54.
During the downward deflection of the bending bar 5 under the action of the needle thread, the distance between the permanent magnet 54 and the Hall sensor 56 is increased, as a result of which the magnetic flux density and thus also the Hall voltage of the Hall sensor 56 will be reduced corresponding to the deflection of the bending bar 5. The Hall voltage is sent to and evaluated in the control device 40.
FIG. 6 shows a second embodiment of the control device 40. The output of the amplifier 10 is connected to the voltmeter 11 and, via an A/D converter 57, to one input E1 of a microprocessor 58. An input device 59 is connected to a second input E2 of the microprocessor 58.
The microprocessor 58 has outputs A1 and A2, of which the output A1 is connected to the setting input S of a flip-flop memory 60, and the output A2 is connected to the setting input S of a flip-flop memory 61. The memories 60 and 61 form a switching device 62.
The output Q of the memory 60 is connected to the display element 33, and that of the memory 61 is connected to the display element 35. Both outputs Q are also connected to the shutoff device 38 of the drive motor 39 via the switch 37.
The second embodiment of the control device 40 operates as follows:
After amplification in the amplifier 10, the differential voltage (U D ) (FIG. 7) is sent to the A/D converter 57. A digital voltage, which is proportional to the differential voltage (U D ) present on the input of the A/D converter 57, is present at the output of the A/D converter 57.
The digital voltage received at the input E1 is evaluated by the microprocessor 58 only at the time intervals in which the tension levels with proportional voltage (U p1 and U p2 ) are formed.
The microprocessor 58 determines the value from all the digital voltages associated with the first tension level (U p1 ), and forms the maximum (U M1 ) from these values. The maximum (U M1 ) is compared with a first threshold value, which is associated with a first limit tension corresponding to a first limit voltage (U G1 ) (FIG. 7). The limit voltage (U G1 ) is to be preselected on the input device 59 depending on the setting of the tensioning device 2, and is sent to the microprocessor 58 via its input E2.
As long as the maximum (U M1 ) corresponds to or exceeds the first threshold value, no signal is sent by the microprocessor 58. However, when the maximum (U M1 ) drops below the first threshold value as a consequence of a pick-up error or a disturbance on the needle thread, the microprocessor 58 sends an impulse from the output A1 to the memory 60, as a result of which the memory 60 is switched over, and activates said display element 33 via its output Q and, with the switch 37 closed, it activates the shutoff device 38 of the drive motor 39.
The maximum (U M2 ) is formed from the values of the digital voltages associated with the second tension peak corresponding to voltage peak (U 2 ,2) of the tension level corresponding to voltage level (U p2 ) and compared with a second threshold value, which is associated with a second limit tension corresponding to a limit voltage (U G2 ) (FIG. 7). Like the limit voltage (U G1 ), this is to be preselected on the input device 59 depending on the setting of the tensioning device 2.
When the maximum (U M2 ) corresponds to or exceeds the second threshold value, no signal is sent by the microprocessor 58. However, when the maximum (U M2 ) drops below the second threshold value as a consequence of a stitch-down error or a disturbance on the looper thread, the microprocessor 58 sends from its output A2 an impulse to the memory 61. As a result, this is switched over, and controls, via its output Q, the display element 35 and the shutoff device 38 of the drive motor 39.
The memories 60 and 61 can be switched over to their starting position by an electrical signal to the resetting input (R).
By presetting different limit voltages (U G1 , U G2 ) for the different maxima (U M1 and U M2 ), the respective threshold value can be optimally adjusted to the corresponding maximum.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
|
A stitch forming machine is provided including a transducer for determining the tension present in a thread, wherein the thread tension assumes a higher value during stitch formation and the transducer provides a signal representing the tension level. The control is provided for evaluating the signal corresponding to the tension level. The control includes a comparator device for comparing a peak of the signal representing the tension level, which peak can be used to detect a malfunction, with a limit signal, corresponding to a limit tension. The comparator sends a signal to a switching device when a signal peak drops below the limit signal. The switching device may be connected to a shut-off device of the drive motor of the machine as well as one or more display elements. In this way, the machine may be stopped and the display element associated with a limit tension, below which the tension dropped by a switching device. The comparator may, according to another aspect of the invention, only provide a signal for energizing a switch depending upon a stitch formation phase associated with a signal peak which drops below a limit signal.
| 3
|
TECHNICAL FIELD
[0001] The present application relates to certain aluminum alloys. More particularly, aluminum alloys are described that exhibit improved properties at elevated temperatures.
BACKGROUND
[0002] Aluminum alloys as a class are some of the most versatile engineering and construction materials available. For example, aluminum alloys are light in comparison to steel or copper and have high strength to weight ratios. Additionally, aluminum alloys resist corrosion, are up to three times more thermally conductive than steel, and can be easily fabricated into various forms. However, current commercial light-weight age-hardenable aluminum alloys are not useable above about 220° C. (428° F.) because the strengthening precipitates they contain dissolve, coarsen or transform to undesirable phases. Although aluminum-scandium alloys have been developed that can withstand higher temperatures, they are typically very expensive due to the costs associated with the use of scandium. Thus, there is a need for commercially viable uncladded aluminum alloys that have good processability characteristics and can be used in applications that are exposed to higher temperatures (e.g. 300-450° C. or 572-842° F.), such as automotive brake rotors or engine components. Cast iron, which is about three times heavier than aluminum, or titanium alloys, which are much more expensive than aluminum alloys, are commonly used for these high temperature, high stress applications.
[0003] Other potential applications for such aluminum superalloys include engine components such as pistons, where car manufacturers presently are limited to aluminum components that operate at a maximum temperature of about 220° C., therefore reducing engine efficiency, increasing emissions, and inflating the cost and mass of the cooling system. Another application is for aircraft engine structural components, such as the auxiliary power unit (APU) located in the tails of airplanes. APU frames, mounting brackets, and exhaust ducting currently use expensive titanium alloys due to the high-temperature environment of about 300° C. (572° F.), which could be replaced by lighter, much less expensive high-temperature aluminum alloys that are disclosed herein.
[0004] An inventive alloy, described herein in various embodiments, comprises aluminum, zirconium, and at least one inoculant, such as a Group 3A, 4A, and 5A metal or metalloid, and include one or more types of nanoscale Al 3 Zr precipitates. An alloy also can include aluminum, zirconium, a lanthanide series metal such as erbium and at least one inoculant, such as Group 3A, 4A, and 5A metals and metalloids. Such an alloy can have one or more nanoscale high number density precipitates such as Al 3 Zr, Al 3 Er, and Al 3 (Zr,Er) precipitates. The inventive alloy exhibits good strength, hardness, creep resistance and aging resistance at elevated temperatures and excellent electrical and thermal conductivity at all temperatures, while being less expensive than Sc-bearing aluminum alloys.
SUMMARY OF INVENTION
[0005] This application is directed to, inter alia, aluminum-zirconium and aluminum-zirconium-lanthanide superalloys that can be used in high temperature, high stress and a variety of other applications. The lanthanide is preferably holmium, erbium, thulium or ytterbium, most preferably erbium. Also, methods of making the aforementioned alloys are disclosed. The superalloys, which have commercially-suitable hardness at temperatures above about 220° C., include nanoscale Al 3 Zr precipitates and optionally nanoscale Al 3 Er precipitates and nanoscale Al 3 (Zr,Er) precipitates that create a high-strength alloy capable of withstanding intense heat conditions. These nanoscale precipitates have a L1 2 -structure in α-Al(f.c.c.) matrix, an average diameter of less than about 20 nanometers (“nm”), preferably less than about 10 nm, and more preferably about 4-6 nm and a high number density, which for example is larger than about 10 21 m 3 , of the nanoscale precipitates. Additionally, methods for increasing the diffusivity of Zr in Al are disclosed.
[0006] A first embodiment of the invention is directed to an alloy of aluminum (including any unavoidable impurities) alloyed with zirconium, and one or more of the following elements: tin, indium, antimony, and magnesium, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0007] A second embodiment of the invention is directed to an alloy of aluminum (including any unavoidable impurities) alloyed with zirconium, erbium and one or more of the following elements: silicon, tin, indium, antimony, and magnesium, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0008] A third embodiment of the invention is directed to an alloy of aluminum (including any unavoidable impurities) alloyed with zirconium and a combination of any two, three, four, or all five of the following elements: silicon, tin, indium, antimony and magnesium, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0009] A fourth embodiment of the invention is directed to an alloy of aluminum (including any unavoidable impurities) alloyed with zirconium, a lanthanide series metal preferably holmium, erbium, thulium or ytterbium, most preferably erbium, and a combination of any two, three, four, or all five of the following elements: silicon, tin, indium, antimony and magnesium, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 X precipitates and nanoscale Al 3 (Zr,X) precipitates having a L1 2 -structure, where X is a lanthanide series metal.
[0010] A fifth embodiment is directed to an alloy of about 0.3 atomic percent (“at. %”) Zr (all concentrations herein are given in atomic percent unless otherwise indicated), about 1.5 at. % Si, about 0.1 at. % Sn, about 0.1 at. % In, about 0.1 at. % Sb, the balance being aluminum and any unavoidable impurities, the alloy further including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0011] A sixth embodiment is directed to an alloy of about 0.1 at. % Zr, about 0.01 at. % Sn, and the balance being aluminum and any unavoidable impurities, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0012] A seventh embodiment is directed to an alloy of about 0.1 at. % Zr, about 0.02 at. % Sn, and the balance being aluminum and any unavoidable impurities, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0013] An eighth embodiment is directed to an alloy of about 0.06 at. % Zr, about 0.02 at. % In, and the balance being aluminum and any unavoidable impurities, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0014] A ninth embodiment is directed to an alloy of about 0.3 at. % Zr, about 0.05 at. % Er, about 1.5 at. % Si, about 0.1 at. % Sn, about 0.1 at. % In, about 0.1 at. % Sb, and the balance being aluminum and any unavoidable impurities, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0015] A tenth embodiment is directed to an alloy of about 0.1 at. % Zr, about 0.04 at. % Er, about 0.01 at. % Sn, and the balance being aluminum and any unavoidable impurities, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0016] An eleventh embodiment is directed to an alloy of about 0.1 at. % Zr, about 0.04 at. % Er, about 0.02 at. % Sn, and the balance being aluminum and any unavoidable impurities, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0017] A twelfth embodiment comprises an alloy of about 0.1 at. % Zr, about 0.04 at. % Er, about 0.2 at. % Si, and the balance being aluminum and any unavoidable impurities, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0018] A thirteenth embodiment is directed to an alloy of about 0.1 at. % Zr, about 0.04 at. % Er, about 0.02 at. % In, and the balance being aluminum and any unavoidable impurities, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0019] A fourteenth embodiment is directed to an alloy of about 0.1 at. % Zr, about 0.04 at. % Er, about 0.02 at. % antimony, and the balance being aluminum and any unavoidable impurities, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0020] A fifteenth embodiment is directed to an alloy of Al—Zr—X—Si—Mg, wherein Si and Mg are alloying elements and X can be a Group 3A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure. Alloying elements are understood to be elements typically present in commercial aluminum alloys such as 1000 to 8000 series alloys, for example.
[0021] A sixteenth embodiment is directed to an alloy of Al—Zr—X—Si—Mg, wherein Si and Mg are alloying elements and X is a Group 4A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0022] A seventeenth embodiment is directed to an alloy of Al—Zr—X—Si—Mg, wherein Si and Mg are alloying elements and X can be a Group 5A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0023] An eighteenth embodiment is directed to an alloy of Al—Zr—Er—X—Si—Mg, wherein Si and Mg are alloying elements and X is a Group 3A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0024] A nineteenth embodiment is directed to an alloy of Al—Zr—Er—X—Si—Mg, wherein Si and Mg are alloying elements and X is a Group 4A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0025] A twentieth embodiment is directed to an alloy of Al—Zr—Er—X—Si—Mg, wherein Si and Mg are alloying elements and X is a Group 5A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0026] A twenty-first embodiment is directed to an alloy of Al—Zr—X—Fe, wherein Fe is an alloying element and X can be a Group 3A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0027] A twenty-second embodiment is directed to an alloy of Al—Zr—X—Fe, wherein Fe is an alloying element and X is a Group 4A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0028] A twenty-third embodiment is directed to an alloy of Al—Zr—X—Fe, wherein Fe is an alloying element and X can be a Group 5A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0029] A twenty-fourth embodiment is directed to an alloy of Al—Zr—Er—X—Fe, wherein Fe is an alloying element and X is a Group 3A metal or metalloid., the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0030] A twenty-fifth embodiment is directed to an alloy of Al—Zr—Er—X—Fe, wherein Fe is an alloying element and X is a Group 4A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0031] A twenty-sixth embodiment is directed to an alloy of Al—Zr—Er—X—Fe, wherein Fe is an alloying element and X is a Group 5A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0032] A twenty-seventh embodiment is directed to an alloy of Al—Zr—X—Mg, wherein Mg is an alloying element and X can be a Group 3A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0033] A twenty-eighth embodiment is directed to an alloy of Al—Zr—X—Mg, wherein Mg is an alloying element and X is a Group 4A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0034] A twenty-ninth embodiment is directed to an alloy of Al—Zr—X—Mg, wherein Mg is an alloying element and X can be a Group 5A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0035] A thirtieth embodiment is directed to an alloy of Al—Zr—Er—X—Mg, wherein Mg is an alloying element and X is a Group 3A metal or metalloid., the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0036] A thirty-first embodiment is directed to an alloy of Al—Zr—Er—X—Mg, wherein Mg is an alloying element and X is a Group 4A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0037] A thirty-second embodiment is directed to an alloy of Al—Zr—Er—X—Mg, wherein Mg is an alloying element and X is a Group 5A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0038] A thirty-third embodiment is directed to an alloy of Al—Zr—X—Cu, wherein Cu is an alloying element and X can be a Group 3A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0039] A thirty-fourth embodiment is directed to an alloy of Al—Zr—X—Cu, wherein Cu is an alloying element and X is a Group 4A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0040] A thirty-fifth embodiment is directed to an alloy of Al—Zr—X—Cu, wherein Cu is an alloying element and X can be a Group 5A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0041] A thirty-sixth embodiment is directed to an alloy of Al—Zr—Er—X—Cu, wherein Cu is an alloying element and X is a Group 3A metal or metalloid., the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0042] A thirty-seventh embodiment is directed to an alloy of Al—Zr—Er—X—Cu, wherein Cu is an alloying element and X is a Group 4A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0043] A thirty-eighth embodiment is directed to an alloy of Al—Zr—Er—X—Cu, wherein Cu is an alloying element and X is a Group 5A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0044] A twenty-ninth embodiment is directed to an alloy of Al—Zr—X—Si, wherein Si is an alloying element and X can be a Group 3A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0045] A fortieth embodiment is directed to an alloy of Al—Zr—X—Si, wherein Si is an alloying element and X is a Group 4A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0046] A forty-first embodiment is directed to an alloy of Al—Zr—X—Si, wherein Si is an alloying element and X can be a Group 5A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0047] A forty-second embodiment is directed to an alloy of Al—Zr—Er—X—Si, wherein Si is an alloying element and X is a Group 3A metal or metalloid., the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0048] A forty-third embodiment is directed to an alloy of Al—Zr—Er—X—Si, wherein Si is an alloying element and X is a Group 4A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0049] A forty-fourth embodiment is directed to an alloy of Al—Zr—Er—X—Si, wherein Si is an alloying element and X is a Group 5A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0050] A forty-fifth embodiment is directed to an alloy of Al—Zr—X—Zn—Mg, wherein Zn and Mg are alloying elements and X can be a Group 3A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0051] A forty-sixth embodiment is directed to an alloy of Al—Zr—X—Zn—Mg, wherein Zn and Mg are alloying elements and X is a Group 4A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0052] A forty-seventh embodiment is directed to an alloy of Al—Zr—X—Zn—Mg, wherein Zn and Mg are alloying elements and X can be a Group 5A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0053] An forty-eighth embodiment is directed to an alloy of Al—Zr—Er—X—Zn—Mg, wherein Zn and Mg are alloying elements and X is a Group 3A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0054] A forty-ninth embodiment is directed to an alloy of Al—Zr—Er—X—Zn—Mg, wherein Zn and Mg are alloying elements and X is a Group 4A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0055] A fiftieth embodiment is directed to an alloy of Al—Zr—Er—X—Zn—Mg, wherein Zn and Mg are alloying elements and X is a Group 5A metal or metalloid, the alloy including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0056] A fifty-first embodiment of the invention is directed to an alloy of aluminum, zirconium, and one or more of the following elements: tin, indium and antimony, the alloy being essentially scandium free and including a plurality of nanoscale Al 3 Zr precipitates having a L1 2 -structure.
[0057] A fifty-second embodiment of the invention is directed to an alloy of aluminum, zirconium, erbium and one or more of the following elements: silicon, tin, indium and antimony, the alloy being essentially scandium-free and including a plurality of nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure.
[0058] In another aspect of the invention, the Al 3 Zr precipitates and/or nanoscale Al 3 Er precipitates and/or nanoscale Al 3 (Zr,Er) precipitates are less than about 10 nm in average diameter. In another aspect of the invention, the Al 3 Zr precipitates and/or nanoscale Al 3 Er precipitates are about 4-6 nm in average diameter.
[0059] In another aspect of the invention, disclosed is a method of forming an essentially scandium-free aluminum alloy having a plurality of nanoscale precipitates having a L1 2 -structure that are selected from the group consisting of Al 3 Zr, Al 3 Er and Al 3 (Zr,Er)L1 2 . The method may include the following steps: (a) making a melt of aluminum and an addition of zirconium, and one or more of erbium, silicon, tin, indium, antimony, and magnesium; (b) solidifying the melt and cooling the resulting solid piece to a temperature of about 0° C. (32° F.) to about 300° C. (572° F.); (c) optionally homogenizing the solid piece at a temperature of about 600° C. (1112° F.) to about 660° C. (1220° F.) (e.g., 640° C. or 1184° F.) for about 0.3 hour to about 72 hours; (d) optionally performing a first heat-treating step to precipitate some of the alloying elements, which includes maintaining a temperature of about 100° C. (212° F.) to about 375° C. (707° F.) for about 1 to about 12 hours; and (e) after the first optional heat-treating step, performing a main heat treating step that comprises heating and maintaining a temperature of about 375° C. (707° F.) to about 550° C. (1022° F.) for about 1 hour to 48 hours.
[0060] In another aspect of the invention, disclosed is a method of forming an essentially scandium-free aluminum alloy having a plurality of nanoscale Al 3 Zr precipitates or nanoscale Al 3 Zr precipitates, nanoscale Al 3 Er precipitates, and nanoscale Al 3 (Zr,Er) precipitates having a L1 2 -structure. The method may include the following steps: (a) making a melt of aluminum and an addition of zirconium, and one or more of erbium, silicon, tin, indium, antimony, and magnesium; (b) solidifying the melt and cooling the resulting solid piece to a temperature of about 0° C. (32° F.) to about 300° C. (572° F.); (c) optionally homogenizing the solid piece at a temperature of about 600° C. (1112° F.) to about 660° C. (1220° F.) (e.g., 640° C. or 1184° F.) for about 0.3 hour to about 72 hours; (d) performing a first heat-treating step by maintaining a temperature of about 100° C. (212° F.) to about 375° C. (707° F.) for about 1 hour to about 12 hours; and (e) performing a second heat-treating step maintaining a temperature of about 375° C. (707° F.) to about 550° C. (1022° F.) for about 1 hour to 48 hours.
[0061] Additional details and aspects of the disclosed aluminum alloys and methods of making will be described in the following description, including drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0062] FIG. 1 is graphical illustration of measured activation energies for diffusion of solutes in α-Al matrix, which scales with the relative diffusivities of Sc, Group 4B elements (Ti, Zr, and Hf) and some selected inoculants.
[0063] FIGS. 2A and 2B displays the temporal evolution of the Vickers microhardness, FIG. 2A , and electrical conductivity at room temperature, FIG. 2B , during isochronal aging in steps of 25° C./3 hours for Al-0.1 Zr at. %, Al-0.1 Zr-0.01 Sn at. %, and Al-0.1 Zr-0.02 Sn at. %, after homogenization at 640° C. (1184° F.) for 24 hours.
[0064] FIGS. 3A and 3B show the temporal evolution of the Vickers microhardness, FIG. 3A , and electrical conductivity at room temperature, FIG. 3B , during isochronal aging in steps of 25° C./3 hours for Al-0.1 Zr-0.02 Sn at. %, after either homogenization at 640° C. (1184° F.) for 24 hours or without homogenization, e.g., as-cast. Data for Al-0.1 Zr at. % alloy are also included for comparison.
[0065] FIGS. 4A and 4B show the temporal evolution of the Vickers microhardness, FIG. 4A , and electrical conductivity at room temperature, FIG. 4B , during isochronal aging in steps of 25° C./3 hours for Al-0.06 Zr at. % without homogenization and Al-0.06 Zr-0.02 In at. % after homogenization at 640° C. (1184° F.) for 24 hours.
[0066] FIGS. 5A and 5B show the temporal evolution of the Vickers microhardness, FIG. 5A , and electrical conductivity at room temperature, FIG. 5B , during isochronal aging in steps of 25° C./3 hours for Al-0.1 Zr-0.04 Er at. %, Al-0.1 Zr-0.04 Er-0.01 Sn at. % and Al-0.1 Zr-0.04 Er-0.02 Sn at. %, after homogenization at 640° C. (1184° F.) for 24 hours.
[0067] FIGS. 6A and 6B show the temporal evolution of the Vickers microhardness, FIG. 6A , and electrical conductivity at room temperature, FIG. 6B , during isochronal aging in steps of 25° C./3 hours for Al-0.1 Zr-0.04 Er at. %, Al-0.1 Zr-0.04 Er-0.02 In at. %, Al-0.1 Zr-0.04 Er-0.02 Sb at. % and Al-0.1 Zr-0.04 Er-0.17 Si at. %, after homogenization at 640° C. (1184° F.) for 24 hours.
[0068] FIGS. 7A and 7B show the temporal evolution of the Vickers microhardness, FIG. 7A , and electrical conductivity at room temperature, FIG. 7B , during isochronal aging in steps of 25° C./3 hours for Al-0.1 Zr-0.04 Er at. %, after homogenization at 640° C. (1184° F.) for 24 hours, and Al-0.1 Zr-0.04 Er-0.02 In at. %, Al-0.1 Zr-0.04 Er-0.02 Sb at. %, without homogenization.
[0069] FIG. 8A is a summary illustration of the microhardness increases, from the base value of 200 MPa, of the first and second peak-hardness, during isochronal aging in steps of 25° C./3 hours for Al-0.06 Zr at. %, Al-0.06 Zr-0.02 In at. %, Al-0.1 Zr at. %, Al-0.1 Zr-0.01 Sn at. %, Al-0.1 Zr-0.02 Sn at. %, after homogenization at 640° C. (1184° F.) for 24 hours.
[0070] FIG. 8B is a summary illustration of the microhardness increases, from the base value of 200 MPa, of the first and second peak-hardness, during isochronal aging in steps of 25° C./3 hours for Al-0.1 Zr-0.04 Er at. %, Al-0.1 Zr-0.04 Er-0.01 Sn at. %, Al-0.1 Zr-0.04 Er-0.02 Sn at. %, Al-0.1 Zr-0.04 Er-0.17 Si at. %, after homogenization at 640° C. (1184° F.) for 24 hours; and Al-0.1 Zr-0.04 Er-0.02 In at. %, Al-0.1 Zr-0.04 Er-0.02 Sb at. %, without homogenization.
[0071] FIG. 9 is a 3-D atom-probe tomographic reconstruction of the Al-0.1 Zr-0.02 Sn at. %, after homogenization at 640° C. (1184° F.) for 24 hours, then being aged at 400° C. (752° F.) for 72 hours, showing the Al 3 Zr nano-precipitates with a diameter of about 8-12 nm. FIG. 9 also includes a magnified reconstruction of a pair of nanoprecipitates, exhibiting Zr atoms (green) and Sn atoms (red). 12 at. % Zr was used as isoconcentration surface in the analysis to differentiate the precipitates from the matrix.
DETAILED DESCRIPTION OF INVENTION
[0072] It should be understood that the present disclosure is to be considered as an exemplification of the present invention, which has multiple embodiments, and is not intended to limit the invention to the specific embodiments illustrated. It should be further understood that the title of this section of this application (“Detailed Description of the Invention”) relates to a requirement of the United States Patent Office, and should not be found to limit the subject matter disclosed herein.
[0073] Novel aluminum based superalloys are disclosed. The alloys comprise aluminum, zirconium and at least one inoculant, and include nanoscale Al 3 Zr precipitates. Also disclosed are alloys that comprise aluminum, zirconium, a lanthanide preferably holmium, erbium, thulium or ytterbium, most preferably erbium, and at least one inoculant, and include nanoscale Al 3 Zr precipitates, nanoscale Al 3 lanthanide precipitates, and Al 3 (Zr,lanthanide) precipitates. These superalloys are readily processable and have high heat resistance, especially at about 300-450° C. (572-842° F.). Further, a method for increasing the diffusivity of zirconium in aluminum by using a Group 3A, Group 4A or Group 5A metal or metalloid as an inoculant is disclosed. Also, a method for decreasing the precipitate diameter of Al 3 Zr(L1 2 ) precipitates by the use of an inoculant is described. Inoculants such as Group 3A, 4A, and 5A metals or metalloids are provided in sufficient amounts to provide for the formation of the high number density of nanoscale precipitates, and includes the amounts described in the Examples and Figures.
[0074] A contemplated aluminum alloy also can be essentially scandium-free (meaning that scandium (Sc) is present in a range of less than about 0.04 at % to about 0.00 at. % of the alloy), while displaying the same or improved mechanical properties at ambient and elevated temperatures when compared to scandium-containing aluminum alloys. The conventional wisdom is that the elimination of Sc in the alloy is unlikely to succeed, because, for example, no other elements possess the same thermodynamic and kinetic properties as Sc in the α-Al matrix, including eutectic (rather than peritectic) solidification, relatively high solubility in solid aluminum near the melting point, said solubility decreasing to near zero values at about 200° C. (392° F.), ability to create coherent and semi-coherent Al 3 X precipitates, wherein X is a metal, having (L1 2 structure) with high resistance to shearing, with low coarsening rate tendency and with a small lattice parameter mismatch with Al, diffusivities small enough to prevent coarsening, but fast enough to permit homogenization, high corrosion and oxidation resistance after dissolution, low density, sufficiently low melting point to allow for rapid dissolution in liquid aluminum. For example, as illustrated in FIG. 1 , diffusivity of zirconium in aluminum is two to three orders of magnitude slower than Sc. Because of this small diffusivity, dilute Al—Zr alloys cannot be strengthened by a high number density of nanoscale Al 3 Zr(L1 2 ) precipitates during aging at low temperatures where the chemical driving force for nucleation is very high.
[0075] FIGS. 2A, 3A and 4A show that for the binary Al-0.06 Zr and Al-0.1 Zr, precipitation occurs at high temperatures (the peak hardness is at about 500° C.), leading to relatively low peak microhardness. This is because Al 3 Zr precipitates, which are responsible for the microhardness increase, form with relatively large sizes of 20 nm to 200 nm, because the supersaturation is smaller and diffusion is faster at the higher temperature.
[0076] It is thus desirable to add an inoculant that shifts the temperature of precipitation to lower temperatures by increasing the diffusivity of Zr in Al, thus increasing the supersaturation of Zr in Al. In such alloys, aging at a temperature of about 200° C. (392° F.) to about 400° C. (752° F.) creates smaller precipitates with higher volume fractions, which are thus more effective strengtheners. Zirconium, however, diffuses very slowly in that range of temperature, and thus does not nucleate small precipitates, with diameters smaller than 20 nm, in aluminum. During artificial aging at a higher temperatures of about 400° C. (752° F.) to about 600° C. (1112° F.), or during cooling to a solid mass from a melt, Al 3 Zr precipitates can be formed, but with relatively large diameters of about 20 nm to about 200 nm. Therefore, an aluminum alloy, containing only zirconium typically is unsatisfactory in forming a high-strength alloy.
[0077] It has been discovered that the presence of one or more of the following elements: tin, indium, and antimony, in an aluminum-zirconium alloy can create a high-strength alloy. Silicon also can be used in conjunction with one or more of these elements. It is believed that atoms of tin, indium, and antimony bind with zirconium atoms to provide for faster diffusion of zirconium in aluminum. Thereafter, smaller Al 3 Zr precipitates can be created during artificial aging at lower temperatures, of about 300° C. (572° F.) to about 400° C. (752° F.), as compared to Al—Zr alloys free of an inoculant. These nanoscale precipitates form and have average diameters that are less than about 20 nm and preferably less than about 10 nm, and more preferably about 4-6 nm. An example is shown in FIG. 9 , a 3-D atom-probe tomographic reconstruction of the Al-0.1 Zr-0.02 Sn at. %, after homogenization at 640° C. (1184° F.) for 24 hours, then being aged at 400° C. (752° F.) for 72 hours, showing the Al 3 Zr nano-precipitates with an average diameter of about 8-12 nm.
[0078] Therefore, an aluminum alloy comprising zirconium with one or more of the following inoculants, tin, indium and antimony, and optionally also including silicon, which will create a higher-strength alloy than without inoculants is disclosed.
[0079] It also has been discovered that the addition of erbium in an aluminum-zirconium alloy, further comprising one or more of the following elements, tin, indium and antimony, and optionally also including silicon, can create a high number density of Al 3 Er precipitates during artificial aging at a lower temperature of about 200° C. (572° F.) to about 350° C. (662° F.). These alloys also precipitate Al 3 Zr precipitates at temperatures of about 350° C. (662° F.) to about 550° C. (1022° F.), like those alloys without Er, as well as Al 3 (Zr,Er) precipitates. The nanoscale Al 3 Er precipitates, nanoscale Al 3 Zr precipitates, and nanoscale Al 3 (Zr,Er) precipitates create a combined matrix that displays an improvement in strength compared to an Al 3 Zr alloy with no addition of erbium.
EXAMPLES
[0080] The following examples are set forth to aid in the understanding of the invention, and should not be construed to limit in any way the invention as defined in the claims that follow thereafter.
[0081] Alloys 1-4
[0082] Alloy Composition, Processing and Analytical Techniques
[0083] One binary control alloy and three ternary inoculated alloys were cast with a nominal composition, in atomic percent, at. %, of Al-0.1 Zr, Al-0.1 Zr-0.01 Sn, Al-0.1 Zr-0.02 Sn, Al-0.06 Zr-0.02 In. Master alloys, including 99.99 wt. % pure Al, Al-5.0 Zr wt. %, 99.99 wt. % pure Sn, and 99.99 wt. % pure In, were melted in alumina crucibles in air. The melt was held for 60 minutes at 800° C., stirred vigorously, and then cast into a graphite mold, which was optionally preheated to 200° C. The mold was placed on an ice-cooled copper platen during solidification to enhance directional solidification and decrease formation of shrinkage cavities. The alloy's chemical composition was measured by direct-current plasma atomic-emission spectroscopy (DCP-AES).
[0000]
TABLE 1
Measured Composition, at. %
Alloy
Nominal Composition, at. %
(DCP-AES)
1
A1—0.1 Zr
A1—0.098 Zr
2
A1—0.1 Zr—0.01 Sn
A1—0.086 Zr—0.008 Sn
3
A1—0.1 Zr—0.02 Sn
A1—0.113 Zr—0.019 Sn
4
A1—0.06 Zr—0.02 In
A1—0.062 Zr—0.028 In
[0084] The cast alloys were homogenized in air at about 640° C. for 24 hours (“h”), then water quenched to ambient temperature. Isochronal aging in 3 hour steps of 25° C. for temperatures of about 150° C. to about 550° C. was conducted. All heat treatments were conducted in air and terminated by water quenching to ambient temperature.
[0085] Vickers microhardness measurements were performed with a Duramin-5 microhardness tester (Struers) using a 200 g load applied for 5 seconds(s) on samples polished to a 1 pin surface finish. At least ten indentations across different grains were made per specimen. Electrical conductivity measurements were performed at room temperature using a Sigmatest 2.069 eddy current instrument. Five measurements at 120, 240, 480, and 960 kHz were performed per specimen.
[0086] Isochronal Aging Heat Treatment
[0087] Microhardness and electrical conductivity temporal evolutions of Alloys 1-3 during isochronal aging treatment in stages of 25° C./3 hours, following homogenization at 640° C. for 24 hours, are shown in FIGS. 2A and 2B . In the Al-0.1 Zr control alloy, microhardness commences to increase at 400° C., peaking at about 500° C. with a peak-microhardness of 367±14 MPa. The microhardness peak is due to formation of Al 3 Zr precipitates, which are—relatively large in diameter (>20 nm). The microhardness continuously decreases beyond aging temperature of 500° C. due to precipitates both coarsening and dissolving back into the matrix.
[0088] In the Al-0.1 Zr-0.01 Sn alloy, microhardness commences to increase at 150° C., peaking at about 225° C. for the first time with a microhardness of 287±6 MPa. It then decreases at higher temperatures, but increases again at 375° C., peaking at about 475° C. for the second time with a microhardness of 451±17 MPa. The microhardness continuously decreases beyond an aging temperature of 475° C. Al-0.1 Zr-0.02 Sn behaves similarly to the Al-0.1 Zr-0.01 Sn alloy, except that its first microhardness peak is at a lower temperature of 200° C. with a higher value of 357±9 MPa, and its second microhardness peak is at a lower temperature of 425° C. and a higher value of 493±22 MPa. It is noted that the first peak-microhardness value of Al-0.1 Zr-0.02 Sn, occurring at 200° C. is the same as the peak-microhardness value of Al-0.1 Zr alloy, occurring at 500° C. It is also noted that the addition of 0.01-0.02 at. % of Sn improves peak-microhardness of Al-0.1 Zr from 367 to 451 and 493 MPa, respectively, while decreasing peak temperature. The larger obtained peak-microhardness values in Sn-containing alloys are believed to be due to the formation of smaller nanoscale precipitates with diameters smaller than 10 nm. With the same precipitate volume fraction, a distribution of smaller precipitates proved more effective in strengthening the alloy as compared to an alloy composed of coarser precipitates.
[0089] The temporal evolution of the electrical conductivity of Alloys 1-3 are shown in FIG. 2B . The electrical conductivity of the Al-0.1 Zr alloy is 31.24±0.13 MS/m in the homogenized state. It commences to increase at 425° C., peaking at 475° C. with the value 34.03±0.06 MS/m, which is 58.7% of the International Annealed Copper Standard (IACS). The increase in electrical conductivity is due to precipitation of the Al 3 Zr phase, which removes Zr solute atoms from the Al matrix. The conductivity decreases continuously at higher temperatures, as Al 3 Zr precipitates dissolve and Zr atoms dissolve in the Al matrix. The electrical conductivity evolves temporally for Al-0.1 Zr-0.01 Sn and Al-0.1 Zr-0.02 Sn, which are similar to Al-0.1 Zr alloy, except that their electrical conductivity values commence to increase at lower temperatures, 400° C. and 375° C., respectively. They also peak at lower temperatures, both at 450° C., and at larger values of 34.38±0.06 MS/m (59.3% IACS) and 34.31±0.06 MS/m (59.2% IACS for Al-0.1 Zr-0.01 Sn and Al-0.1 Zr-0.02 Sn alloy, respectively.
[0090] In alloy 3, Al-0.1 Zr-0.02 Sn., FIGS. 3A and 3B show the temporal evolution of the microhardness and electrical conductivity, respectively, both for as-cast and homogenized states (640° C. for 24 hours), during isochronal aging treatment in stages of 25° C./3 hours. They both behave similarly, except for the first microhardness peak, where the as-cast alloy first peaks at 225° C. with the value 293±9 MPa and the homogenized alloy first peaks 200° C. with the value of 357±9 MPa. The temporal evolution of the electrical conductivity-of the two alloys behave similarly.
[0091] FIGS. 4A and 4B show the temporal evolution of the microhardness and electrical conductivity, respectively, of as-cast Al-0.06 Zr without homogenization and homogenized Al-0.06 Zr-0.02 In alloy during isochronal aging treatment in stages of 25° C./3 hours. In the Al-0.06 Zr alloy, the microhardness commences to increase at 400° C., peaking at about 490° C. with a peak-microhardness of 290 MPa. The microhardness peaks, again, due to formation of Al 3 Zr precipitates. In the Al-0.06 Zr-0.02 In alloy, the microhardness commences to increase below 150° C., peaking at about 150° C. for the first time with a microhardness of 321±12 MPa, which is greater than the peak for the Al-0.06 Zr alloy. It then decreases at higher temperatures, but increases again at 400° C., peaking at 475° C. for a second time with the microhardness of 323±10 MPa, which is again greater than the peak microhardness for the Al-0.06 Zr alloy. The microhardness decreases continuously beyond the aging temperature of 475° C. The electrical conductivity of the Al-0.06 Zr alloy is 31.9 MS/m in the as-cast state. It commences to increase at 425° C., peaking at 475° C. with a value of 34.25 MS/m (59.1% IACS). The electrical conductivity of the Al-0.06 Zr-0.02 In alloy is 33.17±0.09 MS/m at the homogenized state. It increases slightly below 150° C., saturates at higher temperatures, increases again at 425° C., peaks at 475° C. with the value 34.00±0.05 MS/m (58.6% IACS).
[0092] The data show that the addition of 0.01-0.02 at. % Sn as an inoculant provides improved microhardness, thus mechanical strength, electrical conductivity, and possibly thermal conductivity, in the Al-0.1 Zr alloy. An addition of 200 ppm In as an inoculant improves microhardness, thus mechanical strength, and slightly decreases electrical conductivity. The inoculants facilitate formation of nanosized precipitates at lower temperatures and create high-strength alloys with precipitates that are less than 20 nm in diameter and are usually less than about 10 nm in diameter.
[0093] FIG. 8A is a summary illustration of the microhardness increases, from the base value of 200 MPa, of the first and second peak-microhardness, during isochronal aging in steps of 25° C./3 hours for all Al-0.06 Zr-based and Al-0.1 Zr-based alloys.
[0094] Alloys 5-10
[0095] Alloy Composition, Processing and Analytical Techniques
[0096] One ternary and five quaternary alloys were cast with a nominal composition, in atomic percent, at. %, of Al-0.1 Zr-0.04 Er, Al-0.1 Zr-0.04 Er-0.17 Si, Al-0.1 Zr-0.04 Er-0.01 Sn, Al-0.1 Zr-0.04 Er-0.02 Sn, Al-0.1 Zr-0.04 Er-0.02 In, Al-0.1 Zr-0.04 Er-0.02 Sb. Master alloys, including 99.99 wt. % pure Al, Al-5.0 Zr wt. %, Al-5.0 Er wt. %, Al-12 Si wt. %, 99.99 wt. % pure Sn, and 99.99 wt. % pure In and 99.99 wt. % pure Sb were melted in alumina crucibles in air. The melt was held for 60 minutes at 800° C., stirred vigorously, and then cast into a graphite mold, which was optionally preheated to 200° C. The mold was placed on an ice-cooled copper platen during solidification to enhance directional solidification and decrease formation of shrinkage cavities. The alloy's chemical composition was measured by direct-current plasma atomic-emission spectroscopy (DCP-AES).
[0000]
TABLE 2
Al-
Measured Composition, at. %
loy
Nominal Composition, at. %
(DCP-AES)
5
A1—0.1 Zr—0.04 Er
A1—0.089 Zr—0.041 Er
6
A1—0.1 Zr—0.04 Er—0.01
A1—0.077 Zr—0.040 Er—0.008 Sn
Sn
7
A1—0.1 Zr—0.04 Er—0.02
A1—0.086 Zr—0.044 Er—0.018 Sn
Sn
8
A1—0.1 Zr—0.04 Er—0.17
A1—0.074 Zr—0.036 Er—0.16 Si
Si
9
A1—0.1 Zr—0.04 Er—0.02
A1—0.125 Zr—0.042 Er—0.026 In
In
10
A1—0.1 Zr—0.04 Er—0.02
A1—0.068 Zr—0.037 Er—0.014 Sb
Sb
[0097] Isochronal Aging Heat Treatment
[0098] The temporal evolutions of microhardness and electrical conductivity were measured for Alloys 5-7 during isochronal aging treatments in stages of 25° C./3 hours, following homogenization at 640° C. for 24 hours, and are shown in FIGS. 5A and 5B . In the Al-0.1 Zr-0.04 Er control alloy without inoculants, the microhardness commences to increase at 200° C., peaking for the first time at 325° C. with a microhardness of 313±3 MPa. It then decreases at higher temperatures, but increases again at 400° C., peaking at 475° C. for the second time with a microhardness of 369±6 MPa. The first peak-microhardness is due to the formation of Al 3 Er precipitates, and the second peak-microhardness is due to precipitation of Al 3 Zr precipitates. The microhardness values decrease continuously above an aging temperature of 475° C. due to both precipitation coarsening and dissolution of the precipitates. In the Al-0.1 Zr-0.04 Er-0.01 Sn alloy, the microhardness values commence to increase at very low temperatures, possibly lower than 150° C., peaking at 200° C. for the first time with a microhardness of 331±8 MPa. It then saturates at higher temperatures, but increases again at 400° C., peaking at 450° C. for the second time with a microhardness of 435±12 MPa, which is greater than for the control alloy. The microhardness decreases continuously above an aging temperature of 450° C. In the Al-0.1 Zr-0.04 Er-0.02 Sn alloy, the microhardness commences to increase at very low temperature, possibly lower than 150° C., peaking at about 150° C. for the first time with a microhardness of 303±6 MPa. The microhardness then saturates at higher temperatures, but increases again at 375° C., peaking at about 425° C. for the second time with a microhardness of 449±16 MPa, which is greater than the control and Al-0.1 Zr-0.04 Er-0.01 Sn alloy. The microhardness decreases continuously above an aging temperature of 425° C.
[0099] The temporal evolution of the electrical conductivity of Al-0.01 Zr-0.04 Er, Al-0.01 Zr-0.04 Er-0.01 Sn, and Al-0.01 Zr-0.04 Er-0.02 Sn, following homogenization at 640° C. for 24 hours, are similar. With a relatively high degree of fluctuation, the electrical conductivity values of the homogenized states are in the range from 32.2 to 32.5 MS/m. They commence to increase at 350° C. to 400° C. then peak at 475° C. with a value of 34.33±0.23 (59.2% IACS) for Al-0.0 Zr-0.04 Er, at 500° C. with a value of 34.27±0.06 (59.1% IACS) for Al-0.01 Zr-0.04 Er-0.01 Sn, and at 450° C. with a value of 34.20±0.06 (59.0% IACS) for Al-0.01 Zr-0.04 Er-0.02 Sn.
[0100] The temporal evolution of the microhardness and electrical conductivity values of Alloys 5 (the control alloy) and 8-10 during isochronal aging treatment in stages of 25° C./3 hours, following homogenization at 640° C. for 24 hours, are shown in FIGS. 6A and 6B . For the Al-0.1 Zr-0.04 Er-0.17 Si alloy, the microhardness commences to increase at 225° C., peaking at about 275° C. for the first time with a microhardness of 316±8 MPa. It then saturates at higher temperatures, but increases again at 350° C., peaking at about 400° C. for the second time with a microhardness of 470±22 MPa, which is greater than the control alloy without an inoculant. The microhardness decreases continuously beyond an aging temperature of 400° C. In the Al-0.1 Zr-0.04 Er-0.02 In alloy the microhardness commences to increase at a very low temperature, possibly lower than 150° C., peaking at about 250° C. for the first time a the microhardness of 362±10 MPa. It then decreases at higher temperatures, but increases again at 425° C., peaking at 450° C. for the second time with a microhardness of 383±11 MPa, which is again greater than the control alloy. The microhardness decreases continuously above an aging temperature of 425° C. The temporal evolution of the microhardness of Al-0.1 Zr-0.04 Er-0.02 Sb exhibits a distinct difference compared to the earlier ones. It commences to increase at 150° C., peaking at about 325° C. for the first time with a microhardness of 291±13 MPa, then decreases at higher temperatures, but increases again at 425° C., peaking at about 475° C. for the second time at 275±10 MPa, which is smaller than for the control alloy. The microhardness decreases continuously above an aging temperature of 475° C.
[0101] For the Al-0.01 Zr-0.04 Er-0.02 In alloy, FIG. 6B , the electrical conductivity of the homogenized state is 32.46±0.12, which increases continuously to 400° C., before rapidly increasing and peaking at 475° C. with the value 34.03±0.13 (58.7% IACS). The electrical conductivity of the Al-0.01 Zr-0.04 Er-0.02 In alloy at a temperature of about 150° C. to about 400° C. is greater than that of the control alloy. In the Al-0.01 Zr-0.04 Er-0.17 Si alloy, the electrical conductivity of the homogenized state is 32.00±0.07, which starts to increase at 350° C., peak at 425° C. with the value 33.46±0.08 (57.7% IACS), and then saturates until 525° C. where it commences decreasing. In the Al-0.01 Zr-0.04 Er-0.02 Sb alloy, FIG. 6B , the electrical conductivity of the homogenized state is 33.69±0.07, which commences to increase at 450° C., peaks at 500° C. with the value 34.41±0.04 (59.3% IACS), and then decreases below 500° C.
[0102] The temporal evolution of the microhardness and electrical conductivity values of Alloys 9-10 during isochronal aging treatment in stages of 25° C./3 hours, without homogenization, and Alloy 5 (the control alloy), following homogenization at 640° C. for 24 hours, are shown in FIGS. 7A and 7B . For the Al-0.1 Zr-0.04 Er-0.02 In alloy, the microhardness commences to increase at 150° C., peaking at about 175° C. for the first time with a microhardness of 340±16 MPa. It saturates from 175° C. to 300° C., then decreases to 350° C. but increases again at 375° C., peaking at about 500° C. for the second time with a microhardness of 427±13 MPa, which is greater than the control alloy without an inoculant. For the Al-0.1 Zr-0.04 Er-0.02 Sb alloy, the microhardness commences to increase at 150° C., peaking at about 200° C. for the first time with a microhardness of 273±10 MPa. It saturates from 200° C. to 250° C., then increases again at 250° C., peaking at about 475° C. for the second time with a microhardness of 463±7 MPa, which is greater than the control alloy without an inoculant.
[0103] For the Al-0.01 Zr-0.04 Er-0.02 In alloy, FIG. 7B , the electrical conductivity of the as-cast state is 31.25±0.12, which saturates to 375° C., before rapidly increasing and peaking at 500° C. with the value 34.69±0.11 (59.8% IACS). In the Al-0.01 Zr-0.04 Er-0.02 Sb alloy, the electrical conductivity of the as-cast state is 31.40±0.09, which saturates to 375° C., before rapidly increasing and peaking at 500° C. with the value 34.52±0.12 (59.5% IACS).
[0104] The addition of any of 0.17 Si, 0.01 Sn, 0.02 Sn, 0.02 In, or 0.02 Sb as inoculants to a Al-0.1 Zr-0.04 Er alloy provides a means for improving microhardness, thus mechanical strength, while maintaining the same relatively high electrical conductivity at peak microhardness. The inoculant facilitates the early formation of precipitates at low temperatures. The precipitates are nanosized and are less than about 20 nm in diameter and are believed to be less than about 10 nm.
[0105] Electrical and thermal conductivities are known to be correlated with one another, so that an improvement in electrical conductivity described herein likely results in a corresponding improvement in thermal conductivity.
[0106] FIG. 8B is a summary illustration of the microhardness increases of the first and second peak-microhardness values, during isochronal aging in steps of 25° C./3 hours for all Al-0.1 Zr-0.04 Er-based alloys.
[0107] The foregoing description and examples are intended as illustrative and are not to be taken as limiting what can be accomplished. Still other variations within the spirit and scope of this invention are possible and will present themselves to those skilled in the art and science of preparing alloys with specific goals for the electrical and thermal conductivities.
|
Aluminum-zirconium and aluminum-zirconium-lanthanide superalloys are described that can be used in high temperature, high stress and a variety of other applications. The lanthanide is preferably holmium, erbium, thulium or ytterbium, most preferably erbium. Also, methods of making the aforementioned alloys are disclosed. The superalloys, which have commercially-suitable hardness at temperatures above about 220° C., include nanoscale Al 3 Zr precipitates and optionally nanoscale Al 3 Er precipitates and nanoscale Al 3 (Zr,Er) precipitates that create a high-strength alloy capable of withstanding intense heat conditions. These nanoscale precipitates have a L1 2 -structure in α-Al(f.c.c.) matrix, an average diameter of less than about 20 nanometers (“nm”), preferably less than about 10 nm, and more preferably about 4-6 nm and a high number density, which for example, is larger than about 10 21 m −3 , of the nanoscale precipitates. The formation of the high number density of nanoscale precipitates is thought to be due to the addition of inoculant, such as a Group 3A, 4A, and 5A metal or metalloid. Additionally, methods for increasing the diffusivity of Zr in Al are disclosed.
| 2
|
BACKGROUND OF THE INVENTION
[0001] At the present time, massive advertisement arrives to most of the population, without being able to segment the target market of clients to who attack by advertisers, likewise this kind of means are ephemeral and very expensive such as the radio and television.
[0002] While the printed advertisements, massive or not, hardly pass through the home door and in most of the cases they do not arrive up to the privacy of the same, this joined together to the fact that some of them have cost for the customer.
[0003] With the purpose to offer tangibles benefits for the advertisers, advertisement supplier and final customers, the present system was development, since it is an efficient and economical system for the advertiser and it has tangible benefits to the advertisement supplier and final customer.
DETAILED DESCRIPTION
[0004] The commercial model of this business, is centered in a franchise scheme, being said franchises responsible for the sale and marketing of advertising spaces which are inside a label, one embodiment of which is identified as the “CLEANPROMO” label or advertising poster, which will be detailed further. A master franchiser makes a selection process of those candidates or persons interested in acquiring the franchise.
[0005] Once the franchise is settled, a market analysis is made in order to determine the supplier universe of “CLEANPROMO” labels (dry cleaning establishments, hotels, and the like), as well as the potential advertiser universe with segmentation by line of business.
[0006] During the first franchise stage the franchisee is trained to carry out the negotiations and closings with suppliers (dry cleaning establishments, hotels, and the like) either in a local manner or with national and international corporations.
[0007] Once the corresponding agreements have been effected with the suppliers and having secured the whole advertisement placement, the commercialization stage of the advertisement space is initiated.
[0008] One embodiment of an instrument on which the advertisement spaces are commercialized is called a “CLEANPROMO” label, which is an offset color selection printing, sized, in a preferred embodiment, of 57×40 cm, printed only at the front and with special tab cut so as to hang it in a hanger for cloths, in addition to paper cuttings or pre-cuts to be able to detach coupons and promotions, preferably printed in bright art paper of 150 g.
[0009] The “CLEANPROMO” label may be divided up to 22 spaces to be commercialized of which sizes vary depending on the location in the same. Aspects of the “CLEANPROMO” label or advertising poster are also disclosed in U.S. patent application Ser. No. 10/905,154, entitled “Advertising Poster Inside or in the Delivering Packing of Garments Processed by Dry Cleaning Establishments, Laundries or Similar Treatment,” which is incorporated herein by reference in its entirety.
[0010] What the franchise promotes is that the franchisee is only responsible for the commercialization of the advertising spaces, while the design, printing, logistic and transportation are responsibility of the master franchiser.
[0011] In this way it is secured that the franchisee in each place, be only worried of the commercial ambit and not of the operation and logistic, which brings as consequence a dedicated and effective commercial net.
[0012] An operation manual for franchises has been developed, which determines the operation model for the commercialization, negotiation of suppliers, as well as design and printing technical details that the “CLEANPROMO” label has to have, maintaining thus quality standards in all of these ambits.
[0013] Support materials will be deliver to each franchiser, such as demonstrative system brochures and folders, so as to facilitate the commercialization, in addition to elements to formalize the operations such as printed forms called “Orders of Entry/Publication” where the advertisements and payments are secured, as well as the advertiser secures the prices continuity and spaces reservations.
[0014] The suppliers with whom the corresponding agreements are signed, are the vehicle to send the advertiser publicity to the customer through a “CLEANPROMO” label, which is inserted in each hook of the dry cleaning establishment order that are processed in the establishment of the suppliers joined together that the last ones receive an economical benefit for each “CLEANPROMO” label inserted.
[0015] The additional labor made by the suppliers is only to insert a “CLEANPROMO” label in the hook of the garment orders to process, so as to place later the plastic bag over the cloths. Therefore, the additional effort made by the supplier can be considered minimum compared with the tangible benefit obtained with the insertion of each “CLEANPROMO” label.
[0016] Hereby the customer directly acquire, without additional cost for him, a full range of benefits which include coupons, discounts, courtesies, publicity, etc. joined together to the fact that he does not have to acquire the publication, unlike of magazines or newspapers and having the additional advantage of having the security that it arrives up to privacy of home, and not only to that person who picks up the dry cleaning orders but they are seen by all the home members.
[0017] Notwithstanding the above mentioned, in this system the publicity distribution is constant and not sporadic, since usually the dry cleaning establishment services are used with certain periodicity and by certain economic sectors of the population, thereby joined together all the advantages before mentioned, the publicity is directed to a specific sector of the population.
[0018] The impact received by the customer with this kind of publicity is novel by virtue that a space is used, which previously at the present invention had not been exploited and all the related parties receive benefit, that is, franchiser, franchisee, supplier, advertiser and customer, thereby the system result almost perfect.
|
This invention is related to an alternative advertising a promotional system with unique features, which offer specific qualities to the advertisers, suppliers and final customers. The object of this invention is to provide a novel, efficient, economical and income producing system, totality different to the ones already existing in the market at the present time, with an operation system and a simple business model.
| 6
|
This application is a §371 US National Entry of International Application No. PCT/EP03/00849 filed Jan. 28, 2003, hereby incorporated herein by reference, which claims priority to German Patent Application Ser. No. 102 03 225.4, filed Jan. 28, 2002.
FIELD OF THE INVENTION
The invention relates to the field of cleaning and disinfection of medical and/or surgical instruments and apparatuses.
BACKGROUND OF THE INVENTION
Creutzfeldt-Jakob Disease (CJD), according to current knowledge, is an encephalopathy caused by prions. Prions are infectious protein particles which cannot be readily destabilized by conventional substances attacking nucleic acid and have high stability toward chemical and physical influences. Cleaning and disinfection of medical or surgical instruments and apparatuses which are possibly contaminated with prions is therefore problematic. In the literature (Bundesgesundheitsblatt July 1998, 279-298), it is proposed to decontaminate instruments contaminated with CJD material using 1 to 2 M NaOH for a period of 24 h, or by steam sterilization for a period of 1 h at 134° C. Alternatively, decontamination using the highly toxic guanidinium thiocyanate is proposed. These decontamination processes are extremely complex and cannot be carried out in the routine preparation of instruments.
SUMMARY OF THE INVENTION
The object underlying the invention is to provide a possible method for the cleaning or disinfection of medical or surgical instruments and apparatuses, in which prions are destabilized with sufficient reliability, preferably are also inactivated. The invention is to be suitable for routine use, in particular in mechanical instrument cleaning and preparation and is not to require any complex separate decontamination, as in the prior art.
The invention therefore relates to the use of a cleaning composition which comprises surfactants and has a pH of at least 11 when diluted in aqueous solution in ready-to-use form, for destabilizing and/or inactivating prions in the mechanical or manual cleaning and/or disinfection of medical and/or surgical instruments and apparatuses.
First some terms used in the context of the invention are to be explained.
DEFINITIONS
The term cleaning composition denotes any ready-to-use formulation which is used either directly or diluted with water for the cleaning or disinfection of the corresponding instruments. In the context of the invention, the term cleaning composition includes the term disinfectant. The cleaning composition can be formulated in solid form or preferably in liquid form. As cleaning solution, that is to say diluted in aqueous solution in ready-to-use form, the cleaning composition has a pH of 11 or above.
The cleaning composition used according to the invention comprises surfactants. This denotes compounds which lower the surface tension, that is to say amphiphilic compounds having at least one hydrophobic moiety and one hydrophilic moiety. In the context of the invention, it is possible to use all surfactants, for example anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants and block copolymers (in particular made from ethylene oxide and propylene oxide units). By way of example, reference is made to Römpp Chemielexikon [Römpp's Chemistry Lexikon], 10th edition, headword “surfactants”.
The invention is used in the mechanical and manual cleaning and/or disinfection of medical and/or surgical instruments and/or apparatuses. “Mechanical” means that the process preferably proceeds automatically in a dishwashing machine and no human intervention is necessary in the course of cleaning or disinfection. In particular, according to the invention, a conventional dishwashing and preparation machine for surgical instruments can be employed. Particularly preferably, the invention is used in mechanical cleaning and disinfection. It can be used, in particular, for routine daily instrument cleaning.
The terms “cleaning and/or disinfection” cover the steps required in the treatment of used instruments and apparatuses up to the preferably sterile state in which they can be reused.
Medical and/or surgical instruments and apparatuses are all appliances used in the medical and hospital sector and parts thereof which are in principle accessible to mechanical cleaning and disinfection.
Destabilizing prions means that infectious prion material possibly adhering to the instrument surface is at least partially destabilized. In a destabilization, the pathogenic conformation of the prion molecule is no longer present.
Prion inactivation has occurred if, in an animal test, it is established that the infectivity of a prion-containing brain extract is no longer present after a treatment with a composition or process under test.
DESCRIPTION OF THE INVENTION
It is known that prions are embedded in fatty tissue and are themselves hydrophobic and are thus accessible with difficulty to water and aqueous solutions.
The invention is based on the surprising finding that prions may be destabilized relatively simply in a strongly alkaline environment, if a surfactant is simultaneously present, in the context of routine, in particular mechanical, instrument cleaning and preparation. The exact mechanism of action of the inventive combination has not been studied, but it is assumed to start from the fact that surfactants loosen the tertiary structure of the prions and thus facilitate their destabilization in the alkaline environment. The pH of the cleaning solution diluted in ready-to-use form is preferably at least 11, further preferably at least 11.5, further preferably at least 12, further preferably at least 12.5. The cleaning composition preferably comprises alkali metal hydroxides such as sodium hydroxide or preferably potassium hydroxide. The use of potassium hydroxide facilitates the provision of a cleaning composition in the form of a concentrate, since potassium hydroxide solutions, at low temperatures, have a lesser tendency to crystallize out than sodium hydroxide solutions. The cleaning composition can additionally comprise alkanolamines.
The addition of surfactants to the highly alkaline cleaning solution can markedly reduce the surface tension and interfacial tension. It is thought that the prions are thereby made more accessible to the alkaline active ingredient and at least the tertiary structure of the prions can be destroyed and the prions can be destabilized or inactivated.
In principle, nonionic surfactants, for example fatty alcohols, are most suitable for reducing the surface tension of an aqueous solution. They have the additional advantage that they foam less and thus prevent or reduce the unwanted foam formation in the cleaning of medical instruments. Foam formation can impair in particular the cleaning of for example narrow-bore tubes of endoscopes or the like. Nonionic surfactants, however, in a strongly alkaline environment, are often difficult to bring into solution. It is therefore preferred in the context of the invention to combine the nonionic surfactant with cationic, anionic or particularly preferably amphoteric surfactants which can act as solubilizer for the nonionic surfactant.
The cleaning solution diluted in ready-to-use form preferably has a surface tension of less than 50 mN/m, preferably less than 40 mN/m, further preferably less than 35 mN/m, further preferably less than 30 mN/m. The surface tension is determined by the plate-ring method as specified in DIN 53993.
A further aspect of the invention is avoiding or reducing the redeposition of prion-containing contaminants on the instruments. The term redeposition denotes the redeposition of a contaminant already removed from a contaminated surface onto another, possibly previously uncontaminated, surface of the instrument to be cleaned. Redeposition is a particular problem with the decontamination, by 24-hour immersion in 1 to 2 M NaOH, recommended in the Bundesgesundheitsblatt (July 1998, 279-298).
The use of surfactants, provided in the context of the invention, already prevents redeposition, since the surfactants can emulsify detached prion constituents and thus keep them in suspension in the aqueous solution. Particularly preferably, in the context of the invention, to avoid or decrease redeposition, the cleaning composition additionally comprises hardness dispersants. Hardness dispersants which can be used are, for example, phosphates and polyphosphates, complexing agents or chelating agents, or other builders. Hardness dispersants support the emulsifying action of the surfactants and thus contribute to the prevention of redeposition.
An important aspect of the invention is its suitability for routine, in particular mechanical, instrument cleaning and preparation. For such routine cleaning, in the prior art, customarily weakly acidic or weakly alkaline (for example enzymatic) cleaners are used, since strongly alkaline solutions can lead to increased loading or corrosion and thus wear of various materials and surfaces which are used in medical instruments and apparatuses. Problems from this point of view are, for example, silicone elastomers, chrome-plated instruments, soldered compounds of silver and tin, adhesive bonds and sealing materials, plastic coatings, for example color codings, glass fiber light conductors and optical surfaces having an antireflection coating. Particular problems are aluminum surfaces, in particular anodized aluminum surfaces, since alkaline solutions exhibit particular aggression toward these. Said problems occur, for example, particularly in the cleaning of endoscopes and constituents thereof, since here the surfaces to be cleaned have a great variety of materials.
In a particularly preferred embodiment of the invention, the cleaning composition therefore additionally comprises corrosion inhibitors. This covers any substance which, in the alkaline solution, inhibits its attack on surfaces, in particular having metallic surfaces such as aluminum or anodized aluminum. Suitable inhibitors are, for example, polymeric silicates, for example waterglass, phosphoric acid esters, or the like. Suitable phosphoric acid esters are mono- and/or diesters of phosphoric acid with aliphatic alcohols of chain length C 1 to C 22 and/or aliphatic diols and/or aliphatic polyols of chain length C 2 to C 22 . Particular preference is given to a diester of phosphoric acid with butanol on one side and ethylene glycol on the other. This ester is commercially available under the name Hordaphos® MDGB. According to the invention, despite the use of highly alkaline cleaning solutions, a mild action on, for example, anodized aluminum surfaces is achieved in this manner.
According to the invention, from the constituents of the cleaning composition, preferably a liquid concentrate is formulated which can be diluted with water to give the ready-to-use cleaning solution. In this concentrate, the alkali content (calculated as KOH) is preferably between 2 and 30% by weight, further preferably 35% by weight, further preferably 10 and 30% by weight, further preferably 15 and 25% by weight. The surfactant content is preferably between 2 and 25% by weight, further preferably 2 and 15% by weight, further preferably 5 and 15% by weight, further preferably 5 and 10% by weight. This concentrate is preferably made up at concentrations of 0.5 to 5, preferably 0.5 to 2, particularly preferably 0.5 to 1.5, percent by volume with water to give a ready-to-use solution.
As mentioned above, the concentrate can comprise at least one complexing agent, in particular chelating agent. The complexing agents serve to soften water and can enhance the cleaning action compared with lime soaps by complexing alkaline earth metal ions. The complexing agents can be homo-, co- or terpolymers based on acrylic acid or alkali metal salts thereof, in addition phosphonic acids or alkali metal salts thereof, for example 1-hydroxyethane-1,1-diphosphonic acid, aminotrismethylenephosphonic acid, ethylenediaminotetrakismethylenephosphonic acid, phosphonobutanetricarboxylic acid, tartaric acid, citric acid and gluconic acid; in addition nitrilotriacetic acid or ethylenediaminetetraacetic acid or salts thereof.
The concentrate can comprise nitrilotriacetic acid and/or a salt of this acid, particularly preferably its trisodium salt. The addition of NTA is advantageous if the concentrate is to be made up with water having high mineral contents (hard water) to give a ready-to-use solution.
To the concentrate, there can be added customary preservatives, for example p-hydroxybenzoic acid or methyl esters thereof, 5-bromo-5-nitro-1,3-dioxane, salicylic acid, 2-naphthyl-m-N-dimethylthiocarbanilate, 5-chloro-5-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one and also mixtures of the two last-mentioned compounds. A preferred preservative is p-hydroxybenzoic acid or methyl esters thereof. Using these preservatives avoids microbial and fungal infestation of the cleaning composition concentrate.
If required, formulation aids (solubilizers) can be added, for example sodium cumenesulfonate, sodium toluene-sulfonate, sodium xylenesulfonate, urea, glycols, in particular polypropylene glycols and polyethylene glycols, methylacetamide and fatty alcohols, for example cetyl alcohol.
The enumeration of possible constituents is not limiting. In addition, it is possible to add, for example, wetting agents, emulsifiers, antifoam agents or the like. It is advantageous, for example, to add N-acyl glutamate as wetting agent.
The time of action of the cleaning composition is according to the invention preferably 1 to 60 min, further preferably 1 to 30 min, further preferably 5 to 30 min, further preferably 10 to 20 min. Before and/or after the action of the inventively used cleaning composition, further preliminary cleaning, cleaning, rinsing or final rinsing or disinfection steps can be provided. It is preferred first to carry out a preliminary rinse to remove coarse contaminants, then to perform an inventive cleaning/disinfection, followed by a rinse with hot water (93° C.) for thermal disinfection and removal of cleaning composition residues.
The cleaning is carried out according to the invention, preferably at a temperature from room temperature to 93° C., further preferably from 40 to 93° C., further preferably from 50 to 80° C., particularly preferably from 50 to 60° C. Likewise preference is given to a temperature range from room temperature (18° C.) to 50° C. or from room temperature to 40° C.
In the case of mechanical cleaning, particular preference is given to temperatures from 50 to 60° C., in particular about 50° C., and a time of action of 10 to 20 min, preferably about 10 min. In the case of manual cleaning by immersion in a cleaning solution, preference is given to a time of action of about 10 min at room temperature. In the case of manual cleaning, preferably a higher concentration, preferably a concentration of the cleaner which is twice as high as in the mechanical cleaning, is used. For example, the cleaner concentrate according to the example 1 below is used in the context of mechanical cleaning preferably in a use concentration of about 0.5% by volume, in manual cleaning at a concentration of 1% by volume.
Illustrative examples of the invention are described hereinafter on the basis of the illustration and the examples.
DESCRIPTION OF THE DRAWINGS
The illustration shows anodized aluminum plates before and after treatment with two different highly alkaline cleaners.
EXPERIMENTAL EXAMPLES
Example 1
A cleaning composition concentrate is prepared according to the table below. The amounts of the starting materials to be used are given in parts by weight.
Potassium tripolyphosphate, 50%
42.78
Potassium hydroxide, 45%
22.32
Sodium alkylaminodipropionate
6.00
Bardac LF 1
0.50
Fatty alcohol, C10/12, 4EO,
0.50
4–5 PO 2
Sodium waterglass
27.90
1 Cationic surfactant (dioctyldimethylammonium chloride)
2 Block copolymer of C10/C12 fatty alcohols having 4 ethylene oxide units and 4–5 propylene oxide units.
Example 2
In a one-tank washing machine for medical and surgical instruments, the instruments which are to be cleaned and which are suspected to have a contamination with prions are first pre-rinsed with cold water. The washing machine is then filled with cold water and the cleaning composition concentrate according to example 1 is added at a concentration of 0.5% by volume. The cleaning solution is heated to 55° C. and circulated for 10 min at this temperature with spraying of the instruments. Rinsing is then performed with cold deionized water. Finally a thermal disinfection with deionized water is performed at 93° C. This thermal disinfection is simultaneously the final rinse.
Example 3
The surface tension was determined as specified in DIN 53993 for the following liquids:
dionized water
73 mN/m
0.1 N NaOH in deionized water
72 mN/m
1% by volume cleaner solution according
33 mN/m
to example 1 in Hamburg city water
It is seen that the cleaning solution from a concentrate according to example 1 has a markedly decreased surface tension compared with a simply alkaline solution. This solution comprises the fatty alcohol as nonionic surfactant and also sodium alkylaminodipropionate as solubilizing amphoteric surfactant.
Example 4
Roughened microscope slides are dirtied with 50 mg of a blood-egg yolk mixture, dried at 55° C. for 2 h and then immersed in a stirred bath for 10 min at room temperature. The medium used for the immersion bath is deionized water, 0.1 N NaOH or a 1% strength by volume cleaning solution of the cleaning composition concentrate according to example 1. The residual amount of fouling then determined is 20% by weight for water, 35% by weight for 0.1 N NaOH and less than 5% by weight for the cleaner, as immersion bath medium used.
Example 5
To test the care of material of anodized aluminum surfaces, anodized aluminum plates are exposed to a cleaning medium in the Miele G7736 dishwashing machine for 10 min at 55° C. Both new colorless and also blue anodized aluminum plates are used. The cleaning medium is 0.1 M NaOH having a pH of 12.7 and a 1% strength by volume cleaning solution of the cleaning composition concentrate according to example 1. The plates are then inspected visually. The results shown in the illustration shows that in the plates treated with NaOH, the anodized layer is markedly eroded. In contrast thereto, the plates treated with the cleaner have no visible damage to the anodized layer.
|
The invention relates to the use of a cleaning agent that contains surfactants and has a pH value of at least 11 when diluted in an aqueous solution and ready for use. Said cleaning agent is used to destabilize prions during mechanical and manual cleaning and/or disinfection of medical and/or surgical instruments and appliances. It has been recognized that this combination enables a reliable destabilization of prions during the mechanical reconditioning of surgical instruments.
| 2
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a semiconductor laser device. It is specifically directed to an improved semiconductor device which, due to a difference between the refractive index of the waveguide portion and the neighboring region results in optical confinement of the emitted light so that the width of the region through which the electrical current passes can be reduced.
2. Description of the Prior Art
The prior art includes semiconductor laser devices having a ridged waveguide structure in which the width of the current passing region is reduced. Referring to FIG. 7, there is shown a distributed feedback semiconductor laser (DFB laser) in which a ridged waveguide structure is employed. The structure includes a semiconductor substrate 50 of a given conductivity type made, for example, of an n-type GaAs, having a major surface. A semiconductor cladding layer 52 having the same conductivity type as the semiconductor substrate 50 and composed, for example, of an n-type AlGaAs is formed on the major surface of the substrate 50 by means of epitaxial growth. An active semiconductor layer 54 made, for example, of GaAs, is then formed on the cladding layer 52 in the same manner. A semiconductor guiding layer 56 having a conductivity opposite to that of the cladding layer 52 and composed, for example, of a p-type AlGaAs is formed on the active layer 54 in the same manner. A periodically corrugated surface which serves as a diffraction grating 58 is formed on the surface of the guiding layer 56 opposite from the active layer 54. The diffraction grating covers the entire surface of the guiding layer and is composed of corrugations which extend laterally, are triangular in cross section, and have a regular pitch interval. After the diffraction grating 58 is formed on the guiding layer 56, a semiconductor cladding layer 60 of the same conductivity characteristics as the guiding layer 56 and composed, for example, of a p-type AlGaAs is formed on the guiding layer 56 by means of epitaxial growth. Then, a semiconductor cap layer of the same conductivity type as the cladding layer 60 and composed, for example, of a p-type GaAs is formed on the cladding layer 60 in the same manner. An etching process is performed selectively to remove both side regions of the cap layer 62 and the cladding layer 60, leaving a central region thereof extending in the longitudinal direction, and the entire lower region of the cladding layer 60, the cap layer 62 comprising only the central region. The cladding layer 60 has a T-shaped cross section. As a result, a stripe structure is formed by the cap and cladding layers 62 and 60. The surfaces of the removed portions of the cap and cladding layers 62 and 60 are covered with insulation films 64. The top surface of the cap layer 62 and the bottom surface of the substrate 50 are provided with counter electrodes 66 and 68 so as to establish ohmic contacts.
In this type of semiconductor laser device, the flow of current can be restricted to a narrow current passing region. However, this type of device does not provide good optical confinement. In order to achieve good optical confinement, the device must be designed to have about 0.01 difference in the refractive index between the central waveguide region and the neighboring region. This difference depends on the effective thickness of the guiding layer 56 (GL) and the thickness d of the neighboring region of the cladding layer 56. However, it is difficult to obtain the desired difference in refractive index by adjusting the thicknesses since the allowable error is so small. Therefore, a device of this type cannot be produced which has consistently predictable optical confinement characteristics.
There has also been proposed a DFB laser having a waveguide which comprises a narrow strip for obtaining uniform and reproducible optical confinement characteristics. One such device is illustrated in FIG. 8 and includes a semiconductor substrate 70 of a given conductivity type composed, for example, of a n-type GaAs, having a major surface. A semiconductor cladding layer 72 of the same conductivity type as the substrate 70 and composed, for example, of n-type AlGaAs is formed on the major surface of the substrate 70 by means of epitaxial growth. An active semiconductor layer 74 composed, for example, of GaAs is then formed on the cladding layer 72 in the same manner. A semiconductor guiding layer 76 having conductivity characteristics opposite to that of the cladding layer 72 and made, for example, of a p-type AlGaAs is formed on the active layer 74 in the same manner. Then, a corrugated strip 78 having a regular period of repitition and which serves as a diffraction grating is formed on the surface of the guiding layer 76 opposite to the active layer 74. Corrugated strip 78 extends over the central region of the guiding layer 76 in a longitudinal direction. The strip 78 defining the diffraction grating is composed of corrugations having a regular pitch and extending perpendicularly to the longitudinal axis thereof. After the diffraction grating 78 is formed on the guiding layers 76, a semiconductor cladding layer 80 of the same conductivity characteristics as the guiding layer 76 and formed, for example, of a p-type AlGaAs is formed on the guiding layer 76 by way of epitaxial growth. Then, a semiconductor cap layer 82 of the same conductivity characteristics as the cladding layer 80 and composed, for example, of a p-type GaAs is formed on the cladding layer 80 in the same manner. Thereafter, ion implantation is performed by injecting ions such as boron ions or the like from the cap layer 82. High resistance current restricting regions 84 are formed on both sides of the cap layer 82 so as to insulate the sections adjacent to central region extending in the longitudinal direction. A pair of counter electrodes 86 and 88 are provided on the top surface of the cap layer 82 and the bottom surface of substrate 70 to establish ohmic contacts therebetween.
This type of semiconductor laser device effectively achieves good optical confinement due to the differences in the refractive indices of the respective sections thereof. However, the current passing region cannot be made narrow so as to increase the reactive current since there is no mechanism for restricting the flow of current to a well defined area within the cladding layer 80.
The aforementioned disadvantages of the semiconductor laser device having a ridged waveguide structure or the narrow strip can also be observed in conventional Fabry-Pe'rot semiconductor lasers.
SUMMARY OF THE INVENTION
The present invention seeks to eliminate the aforementioned disadvantages and to provide a semiconductor laser device which can effectively achieve good optical confinement due to differences in refractive indices, and which also has a narrow current passing region. These effects can be consistently obtained in the devices of the present invention.
In order to accomplish these results, a semiconductor laser of the present invention includes ridge structures and a strip which is defined in the light guide.
More specifically, the semiconductor laser device of the invention may include a semiconductor substrate having a cladding layer thereon of the same conductivity type. A laser active layer is disposed on the cladding layer on the side opposite from the semiconductor substrate. A second semiconductor layer of the opposite conductivity type is disposed on the laser active layer and has a strip waveguide structure for obtaining optical confinement. The strip waveguide structure projects from the second semiconductor layer on the opposite side from the laser active layer and extends to the central area of the second semiconductor layer in a longitudinal direction. A third semiconductor cladding layer of the second named conductivity type is disposed on the strip waveguide. A third semiconductor cladding layer having a ridged waveguide structure for defining the current passage region extends in the longitudinal direction with a width which corresponds to the strip structure. A fourth semiconductor layer of the second conductivity type is disposed on the ridge waveguide structure, and a pair of electrodes is included for supplying a bias voltage, one being connected to the semiconductor substrate and the other to the fourth semiconductor layer.
The refractive index of the third semiconductor cladding layer differs from that of the neighboring region due to the difference in thicknesses so that the center region serves as an optical waveguide. The difference between the refractive indices of the center and neighboring regions may be approximately 0.01 and is preferably in the range from 0.008 to 0.015. The difference in refractive index due strictly to the strip waveguide structure is preferably from 0.007 to 0.013. The ridged structure may project in a perpendicular direction to the third semiconductor cladding layer. The third semiconductor layer may have a plate portion and a ridged portion and has a T-shaped cross section. The thickness of the plate portion may be approximately equal to or less than 5,000A. The thickness of the third semiconductor is approximately 15,000A. The strip waveguide structure may project in a perpendicular direction with respect to the second semiconductor layer. The semiconductor laser device may comprise a Fabry-Pe'rot laser device. The strip waveguide structure may have a periodically corrugated surface which serves as a diffraction grating. The grating may be composed of laterally extending corrugations of regular pitch and of essentially triangular cross section.
In accordance with another phase of the present invention, there is provided a distributed feedback semiconductor laser device which includes a semiconductor substrate of a first conductivity type and a semiconductor cladding layer of the same conductivity type located on the major surface of the semiconductor substrate. A laser active layer is disposed on the cladding layer on the side opposite from the semiconductor substrate. A second semiconductor layer of opposite conductivity type is disposed on the laser active layer and includes a strip waveguide structure having a periodically varying corrugated surface which serves as a diffraction grating. The strip waveguide structure projects from the second semiconductor layer on the side opposite from the laser active layer and extends over the central area of the second semiconductor layer in a longitudinal direction. The corrugated surface has corrugations which extend in a lateral direction perpendicular to the longitudinal direction. A third semiconductor cladding layer of the opposite conductivity type is disposed on the strip waveguide structure and has a ridge waveguide structure for defining an electrical current passing region. The ridge structure projects from the side opposite to the second semiconductor layer and extends in the longitudinal direction. A fourth semiconductor layer of the opposite conductivity type is disposed on the ridge waveguide structure and a pair of electrodes is included for supplying bias voltage, one of the electrodes being connected to the semiconductor substrate and the other to the fourth semiconductor layer.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described more completely in conjunction with the accompanying drawings of a preferred embodiment of the invention. These drawings are strictly for the purpose of explanation and understanding only.
FIG. 1 is an expanded sectional view of a first preferred embodiment of a semiconductor laser device produced according to the present invention;
FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1;
FIG. 3 is a graph showing the relationship between the thickness d of the plate portion of the cladding layer and the difference ΔN in refractive index with respect to various effective thicknesses of guiding layer (GL) in a semiconductor laser device with a ridged waveguide structure;
FIG. 4 is a graph of the difference ΔN in refractive index versus the effective height of the strip structure with respect to various effective thicknesses of guiding layer in a semiconductor laser having a strip waveguide structure;
FIG. 5 is a graph of the relationship between the difference ΔN in refractive index due to the ridged waveguide structure and the thickness d of the plate portion of the cladding layer in which the total difference in refractive index due to the ridged and strip waveguide structures is within the allowable range of from 0.008 to 0.015;
FIG. 6 is a expanded sectional view of a second preferred embodiment of a semiconductor laser device according to the present invention;
FIG. 7 is an expanded perspective view of a prior art semiconductor laser device with a ridged waveguide structure; and
FIG. 8 is an expanded perspective view of a prior art semiconductor laser device with a strip waveguide structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, particularly to FIGS. 1 and 2, the preferred embodiment of a distributed feedback semiconductor laser according to the present invention includes a semiconductor substrate 10 having one conductivity type, such as an n-type GaAs which has a major surface. A semiconductor cladding layer 12 of the same conductivity type as the substrate 10, and preferably consisting of n-type AlGaAs is formed on the major surface of the substrate by means of epitaxial growth. An active semiconductor layer 14 composed, for example, of intrinsic GaAs, is then formed on the cladding layer 12 in the same manner. A semiconductor guiding layer 16 of the second conductivity type opposite to that of the cladding layer 12 is formed on the active layer 14 in the same manner. The guiding layer 16 may consist, for example, of a p-type AlGaAs. A periodically corrugated strip 18 serving as a diffraction grating is formed on the surface of the guiding layer 16 opposite from the active layer 14. The corrugated strip extends over the central area of the surface of the guiding layer 16 in a longitudinal direction whose width is W 2 . The guiding layer 16 consists of a thicker central portion 16a on which the corrugated strip 18 is formed and a pair of thinner plate portions 16b formed on either side of the corrugated strip 18. The effective thickness of the central portion 16a of guiding layer 16 which defines the waveguide is thicker than that of the plate portion 16b. The corrugated strip 18 is composed of corrugations which are essentially triangular in cross section, have a regular pitch, and extend perpendicular to the longitudinal axis of the strip. After the corrugated strip 18 is formed on the guiding layer 16, a semiconductor cladding layer 20 of the same conductivity as that of the guiding layer 16 and composed of a p-type AlGaAs, for example, is formed on the guiding layer 16 by way of epitaxial growth so as to cover the entire surface including the thicker central portion 16a and the thinner plane surface of the guiding layer 16. The band gap of the cladding layer 20 is larger than that of the guiding layer 16 and the active layer 14. A semiconductor cap layer 22 having the same conductivity as that of the cladding layer 20 and made of a p-type GaAs, for example, is formed on the cladding layer 20 in the same manner. Thereafter, an etching process is performed to selectively remove the side portions of the cap layer 22 and the cladding layer 20 to a predetermined depth. A central portion of the cap layer 22 and a portion of the cladding layer 20 having a T-shaped cross section remain after the etching process. The cladding layer 20 comprises a ridged portion 20a having a width W 1 and a plate portion 20b having a thickness d. The ridged portion 20a projects upwardly from the guide layer 16 at a location corresponding to the corrugated strip 18 and extends in the longitudinal direction. The cap layer remains only at the top of the ridged portion 20a. As a result, a ridged waveguide structure is formed by the cap and cladding layers. The surfaces of the removed portions of the cap and cladding layers 22 and 20 are covered with insulation films 24. Moreoever, the top surface of the cap layer 22 and the bottom surface of the substrate 10 are provided with electrodes 26 and 28 so as to establish ohmic contacts therebetween, respectively.
The DFB laser of the present invention has characteristics of both the ridged and strip structures. The characteristics of such a laser device will now be described.
The thickness of the ridge portion should be two or more times that of the plate portion in order to sufficiently prevent the flow of electrical current from spreading laterally and to keep the current flow restricted to a narrow area. The ridged structure differs from a mesa electrode structure in that the thickness d of the plate portion 20b of the cladding layer 20 is equal to or less than about 5,000A and the thicknesses of the ridge portion 20a of cladding layer 20 and the cap layer 22 are about 15,000A and 5,000A respectively, whereas the thickness d is more than about 10,000A in the mesa structure. In an embodiment, the thickness of the third semiconductor layer is 15,000A. As will be described below, the magnitude of difference between the refractive indices of the ridged and plate portions 20a and 20b of the cladding layer begins to be significant when their thicknesses have the aforementioned values. The ridged structure may restrict the flow of electrical current to a narrow region more effectively than does the mesa structure.
In order to achieve the desired electrical current restricting effect, the difference ΔN between the refractive indices of the ridged and plate portions should be at least about 0.01. Since the allowable range of refractive index difference ΔN is, from experience, from 0.08 to 0.015, a difference ΔN in this range will be considered below.
FIG. 3 shows the relationship between the thickness d of the plate portion of the cladding layer and the magnitude of difference ΔN in refractive index, with respect to various effective thicknesses of guiding layer (GL) in the ridge waveguide structure semiconductor laser device. FIG. 4 shows the difference ΔN in refractive index related to the effective height of the strip structure with respect to various effective thicknesses of guiding layer in the strip waveguide structure semiconductor laser.
FIG. 5 shows the relationship between the difference ΔN in refractive index to the ridged waveguide structure and the thickness d of the plate portion of cladding layer 20 on the basis of FIGS. 3 and 4, in which the total difference ΔN in the refractive index due to the ridged and strip waveguide structures is within the allowable range. In FIG. 5, the curved lines a and b correspond to ΔN equals 0.08 and ΔN equals 0.015, respectively. The thickness d of the plate portion of the cladding layer is assumed to be less than 5,000A in the ridged waveguide structure. When the thickness d is greater than about 5,000A, the difference ΔN in refractive index begins to be observed. As seen from FIG. 5, when there is no effect due to the strip waveguide structure, the allowable range represented by the shaded area of the plate portion thickness d of the cladding layer 20 is very narrow. Although it is possible to prevent the flow of electrical current from spreading, relatively large stress is applied to the active layer 14 since the thickness d of the plate portion must be thin when the waveguide strip is not present. When this structure is produced by an etching process, the etching depth is about 19,000A plus or minus 200A and the allowable error is plus or minus 1%, so that very great accuracy is required.
In the preferred embodiment of the present invention, the range of the difference ΔN in the refractive index due to the strip waveguide structure is about 0.007 to 0.013, and the total difference ΔN in the refractive index may be from 0.008 to 0.015. The width W 2 of the diffraction grating may be equal to the width W 1 of the ridged structure. However, it is preferably larger than the width W 1 in order to assume that all of the electrical current passes through the diffraction grating.
In the use of this structure, when the current passage restricting effect of the ridged structure is achieved, the waveguide effect produced by the combination of the strip and ridged structures can also be achieved. It is also possible to extend the allowable error in the plate thickness to permit the ridged structure to be formed by an etching process since the waveguide effect is mainly achieved by the strip. In cases where the difference ΔN in the refractive index due to the strip is about 0.007 to 0.013 when the total difference ΔN between the refractive indices of the central waveguide and the circumference thereof is in the range of 0.008 to 0.015, the permissible error in formation of the ridged structure is greatly extended, so that the etching depth may vary within 1,500A of 16,000A. Therefore, the permissible error of etching is about 10% so that uniform results can be achieved.
The degree of current restricting effect is determined mostly by the width W 1 of the ridged structure and the degree of waveguide effect is determined by the width W 2 of the strip. According to the preferred embodiment of the invention, the widths W 1 and W 2 can be controlled independently of each other Therefore, when the width W 1 the ridged structure is less than the width W 2 of the strip, the degree of current restricting effect can correspond to the degree of waveguide effect, i.e., the area in which current flows can be made to correspond to the area of the diffraction grating so that effective high frequency modulation characteristics can be achieved.
Due to the ridged structure, the area of the electrodes 26 and 28 can be decreased so that the volume of the device can be decreased thereby making high speed modulation possible. Furthermore, the threshold voltage is 20% less than that of a mesa laser. In addition, the device of the present invention provides superior reliability and durability since etching of the active layer is not carried out.
FIG. 6 shows another embodiment of a semiconductor laser device according to the present invention in which after etching of the cladding layer 20 of FIG. 1 is performed, a flush layer 30 composed of n-type AlGaAs is formed on the removed portion of the cladding layer by an epitaxial process. In this embodiment, the flush layer 30 is provided to prevent structural stress from being concentrated at the central portion of the cladding layer 14 by the ridged structure.
It should be evident that various modifications can be made to the described embodiments without departing from the scope of the present invention.
|
A semiconductor laser device including a first semiconductor layer having a strip waveguide structure to obtain optical confinement and a second semiconductor layer having a ridge waveguide structure for defining an electrical current passage region. The strip waveguide structure has a first width, and projects on the first semiconductor layer, extending over the central area of the layer in a longitudinal direction. The ridge waveguide structure projects on the second semiconductor layer and extends in the longitudinal direction with a second width which corresponds to the strip structure. The strip waveguide structure cooperates with the ridge waveguide structure to produce a difference between the refractive index of a center region which extends in the longitudinal direction of the second semiconductor and that of a neighboring region due to the difference in thicknesses between the two, so that the center region serves as an optical waveguide.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from provisional application No. 61/280,835 filed on Nov. 9, 2009.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
Not Applicable
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 —Shows the known conventional design (top schematic), followed by an embodiment with the introduction of the fiberoptic light guide or fiberoptic plate (FOP)
FIG. 2 —Shows an embodiment with treated surfaces
FIG. 3 —Shows an embodiment with treated surfaces and which is hermetically sealed
FIG. 4 —Shows schematics with two opposite sides of the scintillator plate coupled to photodetectors
FIG. 5 —Shows a schematic with four sides of the scintillator plate coupled to photodetectors
FIG. 6 —Shows an embodiment with asymmetrical double-sided coupling utilizing a thinner photodetector variant installed on the incoming front side of the scintillator plate, while the back side is equipped with a larger and potentially more economical photodetector type
FIG. 7 —Shows an embodiment utilizing four photodetectors
DETAILED DESCRIPTION OF THE INVENTION
To achieve high intrinsic spatial resolution in scintillation modules used in PET and SPECT detectors, the scintillator sensors are typically divided into arrays of small pixels. By this mechanical and optical subdivision, the spread of scintillation light for each scintillation event is highly limited which results in more precise definition of the location of the scintillation event, therefore providing better spatial resolution. However, with the desirable resolution limit in pre-clinical and even in dedicated clinical imagers approaching 1 mm and beyond, the production costs of mechanical processing of small size pixel arrays become prohibitive and limit the implementation of the novel high resolution apparatus.
Another approach is to use uncut scintillation plates and apply means that would be in some manner equivalent to the effects provided by pixellation process. This primarily means limiting the light cone size when it. enters the photodetector module(s) and strikes the photocathode(s). Some new now tested approaches (Hamamatsu, Japan) produce separation barriers inside the scintillation plates by inducing microcracks when shining strong and focused laser beams inside the scintillator blocks. While this technique may be used on some scintillators, it is not applicable to others. Indeed one of the new very high performance scintillators, LaBr3, is so delicate that it cannot be reliably processed to achieve small size pixellation, but instead the plates and the pixels crack. In fact this scintillator currently needs to be put in an enclosure to protect it mechanically and also from humidity with an optical window between the scintillator and photodetector. The smallest pixel size achieved in LaBr3 and in small samples was 4 mm which is not sufficient for high resolution imaging. In this case external optical means, like the ones we are disclosing here, could be applied.
The proposed concept is directed towards improving the spatial resolution and its response uniformity across the whole detector module, and especially in the edge regions, while maintaining high energy resolution across the module. It is intended specifically as a remedy to minimize edge effects typically associated and well documented in multiple prior studies when utilizing plate scintillators.
The novel use and the method is to insert and optically couple 1 the optimized, and in some cases specially designed, fiberoptic light guides 2 between the photodetector 3 and the scintillator plate 4 . The main role of the light guide in this concept is to limit the geometrical acceptance of the scintillation light cone 6 , produced in the scintillation plate, at the photodetector surface level or the photodetector's optical window 7 . The gamma ray 8 is depicted at the scintillation point 9 in the drawings. By its limited angular acceptance, and therefore by accepting only the core of the initial light cone, the size of the spot of scintillation light impinging on the photocathode surface is smaller and definition of its center of gravity is less impacted by statistical fluctuations of the scintillation light distribution at the edges of the original light cone. Also, this limited light cone 5 interacts less with the side walls of the scintillation plate and therefore the edge effects are minimized.
FIG. 1 shows the known conventional design (top schematic), followed by an embodiment with the introduction of the fiberoptic light guide or fiberoptic plate (FOP) 2 window between the scintillator and the photodetector (bottom schematic). The FOP limits (or filters) the size of the accepted scintillation light cone at the photocathode surface, while accepting most of the photons in the central (core) region of the original light cone that would be otherwise transmitted to the photodetector in the known design.
Additional accompanying means to enhance this restricted light collection, used together in this conceptual package are:
scintillator plate surface treatments for top surface 10 and side surfaces 11 , depending on particular photodetector structure. The bottom surface of the scintillator plate 12 is labeled in FIGS. 2 and 3 and may also utilize surface treatments. Surface treatments are used to optimize the spatial resolution by increasing or decreasing reflectivity of the surfaces of the scintillator plate. One embodiment is to decrease side surface reflection by using a rough, black, non-reflective surface treatment.
Another embodiment is to increase top surface reflection by using a polished, white, highly reflective surface treatment. Surface treatments may also be used to hermetically seal a hygroscopic scintillator.
wet optical coupling to the photodetector module(s) and the scintillator eliminates the refraction of air layer(s) where the photodetector modules, the FOP, and the scintillator plates adjoin. Through wet optical coupling using known substances such as coupling grease, the refraction caused by air between components may be removed or lessened. structure of the photodetector modules with sensors extending to the very edges of the scintillation plate (no edge dead zones in photodetectors) flexible positional algorithm calculating the 3D position (origin) of the scintillation event in the scintillator plate, changing from one form in the central part of the plate, to other formulas when approaching edges and/or corners. The position of the center of the light cone is related to the initial position of the interaction of the 511 keV annihilation gamma ray in the scintillator. Light in the cone is coming down to the photodetector array and is spread between several photodetector elements. One of the many possible center of gravity (COG) algorithms is used to define the center of the light distribution and therefore through the back projection the position of the initial interaction event. The region where all the COG algorithms have problems are the edge regions, where the shape of the cone gets truncated due to the presence of the edge wall of the scintillator. The quality of the COG algorithm is mostly tested in that region. The preferred algorithm is using the mathematical functional fit to the experimental distribution histogram and therefore is correcting for the truncation phenomenon at the edges. By this the useful volume of the detector is further extended towards the physical edges of the scintillation crystal, in addition to the action of the light guide.
Additional embodiments of the module may vary with two, three, four, five, or six, sides readout. Such embodiments are likely to require that the photodetectors are compact. One preferred type of photodetector for this concept is the Silicon Photomultiplier which comes in different active surface sizes and can be made very compact. With one-sided readout other types of photodetectors such as more traditional position sensitive photo multiplier tubes (PMTs) can be also implemented. FIG. 4 shows schematics with two opposite sides of the scintillator plate coupled to photodetectors. The right schematic exhibits this concept in a hygroscopic scintillator which is hermetically sealed. FIG. 5 depicts a schematic with four sides of the scintillator plate coupled to photodetectors. An option with all six sides of the scintillator plate coupled to photodetectors offers the best light collection resulting in the best definition and spatial resolution of the scintillation light event's 3D positions inside the scintillator plate.
Another embodiment could utilize several types of photodetectors coupled to one scintillator plate. FIG. 6 depicts an embodiment with asymmetrical double-sided coupling utilizing a thinner photodetector variant installed on the incoming front side of the scintillator plate, while the back side is equipped with a larger and potentially more economical photodetector type, such as position sensitive PMT. Another assymetrical embodiment may use odd numbers of one type or varying types of photodetectors coupled to the scintillator plate.
FOP come in many types, but there are two basic varieties, one without and one with black glass extramural absorber (EMA). Typically, the standard FOP does not limit the light cone sufficiently, while the one with EMA is too restrictive and the light cone size becomes too small with too much light absorbed in the FOP. Therefore, our concept calls for a special FOP with intermediate EMA absorber effect which may be achieved by properly tuning the EMA cladding material used. The cladding material typically is plastic, glass, or silica, and should have a lower refractive index than the core fiberoptic material. A range of ideal refraction for the cladding material will depend upon various factors but will be heavily dependent upon the photodetector(s) used. One embodiment of the FOP should allow good transmission of light between about 400 to about 600 nm and have a refractive index from about 1.4 to about 1.6.
Photodetector side optical windows may be used between the scintillator and the photodetector. By placing photodetector optical windows between the fiberoptic light guide and the photodetector, the light accepted by the fiberoptic light guide may be spread to better cope with insensitive areas between individual sensor elements. This spreader window may prevent too large a fraction of the light cone to fall in the dead areas, therefore assuring more uniform detector module response independently of the position of the initial scintillation light generation within the scintillation plate. One enablement of the photodetector optical windows should allow good transmission between about 400 to about 600 nm light and a refractive index from about 1.4 to about 1.6.
|
A first embodiment can comprise increasing three-dimensional spatial resolution of gamma scintillation events in scintillator plates wherein the increase is by inserting a fiberoptic plate light guide between one or more photodetectors and the scintillator and optically coupling the fiberoptic plate light guides to the photodetectors.
| 6
|
Priority
[0001] This application claims priority to provisional application, entitled, DECORATIVE ELEMENTS FOR TO PUMPKINS OR OTHER PIERCEABLE OBJECTS, Serial No. 60/267,632, filed Feb. 9, 2001.
FIELD OF THE INVENTION
[0002] The present invention relates to decorative elements that can be used to create a face or other decoration on a pumpkin or snowman or like base. More particularly, the invention relates to an apparatus and a method for removably attaching decorative elements on a pumpkin or snowman or the like.
BACKGROUND OF THE INVENTION
[0003] Snowmen and pumpkins are examples of objects that are displayed to celebrate or identify a certain season or holiday. Snowmen are part of the tradition and fun of celebrating the winter season. Pumpkins are decorated to celebrate the Halloween holiday. Over the years, the tradition has grown to include decorating other objects in addition to pumpkins and snowmen. For example, Styrofoam forms have been used instead of snow to make snowmen for indoor use in seasonal displays.
[0004] The display of decorated pumpkins is part of the tradition and fun of Halloween. Originally, pumpkins were decorated by cleaning out the soft pulp on the inside, and carving openings representing at least eyes, nose, and mouth. A similar tradition exists in making snowmen during the winter season, wherein a face is often made using decorative elements, for example, a nose of coal and a carrot nose. In modern times, snowmen are often made of Styrofoam or other artificial materials, and kits of decorative elements are provided as described in U.S. Pat. Nos. 3,841,019; 4,322,004; and Des. 267,210.
[0005] The traditional method of decorating a pumpkin is a messy process involving the inconvenience of cleaning out the pumpkin seeds and the soft pulp and allowing for individualizing of the face. This method allows little margin for error, for example, changing of the position of carved features after they are made. For example, if an eye or mouth is placed at a location that is undesirable, it cannot be changed in position. Thus, kits are available which allow for placement and rearrangement of the facial elements, such as one example shown in U.S. Pat. No. 5,091,833. Kits have also evolved to include other decorative elements such as hats, jewelry, and other fanciful objects.
[0006] A limitation of the existing decorative elements for decorating pierceable objects is that insertion and removal of the decorative elements can be difficult. For example, when elements such as ears are attached to a pumpkin, a pin-type element is attached to a decorative body and inserted into the pumpkin. When the pin is inserted into the pumpkin or other like base, the pin becomes engaged in the soft pulpy material of the pumpkin. The fit between the pin and the pumpkin can create a suction or sticking, which makes it difficult to remove the pin from the pumpkin. Furthermore, decorations, made from soft material or paper or other similar material, are removed by pulling on the pin, thereby disengaging it from the pumpkin.
[0007] One disadvantage of using a pin or other like object in attaching a decorative element to a pierceable object such as a pumpkin or snowman is that the pin is hard to grasp, which makes removal difficult. Another disadvantage is that the decorative elements can become separated from the pin by shear forces created between the decorative element and pin due to the suction or sticking force created by the pin in the soft pumpkin. Thus, there exists a need for decorative elements that are easily attached and removed, while reducing the likelihood that a decorative body will separate from a insertion device during insertion and removal and also making the removal easier so that the effect of the suction at the interface between the insertion device and pierceable object is reduced.
SUMMARY OF THE INVENTION
[0008] A decorative element for a pierceable object comprising a decorative body defining an interior chamber, an insertion device having first and second ends, the first end including a grasping section received by the chamber, the grasping section further including a reduced diameter portion defining a grasping portion adjacent to the first end, the second end having distal and proximal sections, the second end having a taper from the distal section to the proximal section, the proximal section located adjacent to the grasping section of the first end of the insertion device.
[0009] A method for decorating a pierceable object comprising grasping a decorative element having a decorative body defining an interior chamber and an insertion device, the insertion device having first and second ends, the first end including a grasping section received by the chamber, the grasping section further including a reduced diameter portion defining a grasping portion adjacent to the first end, the second end having distal and proximal sections, the second end having a taper from the distal to the proximal section, the proximal section located adjacent to the grasping section of the first end of the insertion device, inserting the second end of the insertion device into a pierceable body, grasping the decorative element by the grasping portion, and removing the second end of the insertion device from the pierceable body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is an elevation view of a pierceable object, such as a pumpkin, including a decorative element in accordance with the present invention.
[0011] [0011]FIG. 1A is a section view of one of the decorative element of FIG. 1 along line 1 A- 1 A.
[0012] [0012]FIG. 1B is a section view of one of the decorative elements of FIG. 1 along line 1 B- 1 B.
[0013] [0013]FIG. 2 is a perspective view of one preferred embodiment of an insertion device of one of the decorative elements of the present invention.
[0014] [0014]FIG. 3 is a perspective view of one preferred embodiment of an insertion device of one of the decorative elements of the present invention.
[0015] [0015]FIG. 4 is a perspective view of a decorative element of the present invention.
[0016] [0016]FIG. 5 is a perspective view of a decorative element of the present invention.
[0017] [0017]FIG. 6 is an elevation view of decorative element of the present invention removably secured to a pierceable object.
[0018] [0018]FIG. 7 is an elevation view of a pierceable object, such as a pumpkin, including a decorative element in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] [0019]FIG. 1 shows a pierceable object 12 , in this illustration a pumpkin, having embodiments of decorative elements 10 , 110 of the present invention attached to pierceable object 12 . Although different embodiments of decorative elements 10 , 110 are depicted attached to pierceable object 12 , this is for illustration purposes.
[0020] In one preferred embodiment of the present invention, decorative element 10 includes a decorative body 20 defining an interior chamber 22 and an insertion device 50 . Referring to FIG. 1, decorative body 20 is shown in the shape of an ear. Decorative body 20 can be shaped in a multitude of configurations, including an eye, nose, mouth, ears, hat, or hair. In one embodiment, decorative body 20 of decorative element 10 of the present invention is fabricated from a soft-material. Preferably, soft-material is felt, cotton, wool, or cloth. Decorative body 20 can also be made of other materials including paper, plastic, or rubber.
[0021] As shown in FIG. 1, one embodiment of decorative element 10 of the present invention is shown attached to pierceable object 12 using a plurality of insertion devices 50 . However, it is not necessary for decorative element 10 to be attached by a plurality of insertion devices 50 , As shown in. 7 , decorative element 210 can be attached to pierceable object 300 , in this case a snowman, using one insertion device 150 .
[0022] In one preferred embodiment, insertion device 50 of decorative element 10 of the present invention is fabricated for a material of rigidity sufficient to withstand the pressure exert during insertion into and removal from pierceable object. Preferably insertion device 50 is made of wood or plastic. In another preferred embodiment of the present invention, insertion device 50 is made of metal. Preferably, insertion device 50 is made by molding or stamping.
[0023] As shown in FIG. 1, decorative element 10 is attached to pierceable object 12 by a plurality of insertion devices 50 . Insertion device 50 further has a first end 60 and a second end 70 . First end 60 includes a grasping section 62 . Grasping section 62 includes a reduced diameter portion 64 defining a grasping portion 66 . Second end 70 of insertion device 50 further includes a distal end 72 and a proximal end 74 . Distal end 72 is capable of being removably secured to a pierceable object 12 . Proximal end 74 is located adjacent to grasping section 62 of first end 60 of insertion device 50 .
[0024] Referring to FIG. 3, in one preferred embodiment of insertion device 50 of decorative element 10 of the present invention, a taper is formed from first end 60 to second end 70 . Taper is defined by width of the proximal section 74 of second end 70 , defined by line A-A being greater than width of distal section 72 of second end 70 , defined by line B-B. Tapering proximal section 74 relative to distal section 72 assists insertion and removal of second end 70 of insertion device 50 into and from pierceable object 12 .
[0025] Referring to FIG. 3, in one preferred embodiment, insertion device 50 of decorative element 10 of the present invention has a width W measured along line WW. Preferably, W is between 0.1 and 10 inches. More preferably, W is between 0.5 and 2.0 inches. Most preferably, W is about 1.5 inches. Insertion device 50 of decorative element 10 of the present invention has a length L measured along line L-L. Preferably, L is between 0.25 and 10 inches. More preferably, L is between 0.5 and 4.0 inches. Most preferably, L is about 3.5 inches. Insertion device 50 of decorative element 10 of the present invention has a length thickness T measured along line T-T. Preferably, T is between 0.0125 and 0.5 inches. More preferably, T is between 0.0575 and 0.25 inches. Most preferably, T is about 0.125 inches. Thickness T does not have to be uniform over length L of insertion device 50 .
[0026] Referring to FIG. 2, in one preferred embodiment of insertion device 150 of decorative element 110 of the present invention, a taper is formed from first end 160 to second end 170 . Taper is defined as the width of the proximal section 174 of second end 170 , defined by line A′-A′ being greater than width of distal section 172 of second end 170 , defined by line B′-B′. Tapering proximal section 174 , relative to distal section 172 , assists insertion and removal of second end 170 of insertion device 150 into and from, respectively, pierceable object 12 .
[0027] Referring to FIG. 2, in one preferred embodiment, insertion device 150 of decorative element 110 of the present invention has a width W′ measured along line W′-W′. Preferably, W′ is between 0.1 and 10 inches. More preferably, W is between 0.5 and 2.0 inches. Most preferably, W′ is about 1.5 inches. Insertion device 150 of decorative element 110 of the present invention has a length L′ measured along line L′L′. Preferably, L′ is between 0.25 and 10 inches. Preferably, L′ is between 0.5 and 4.0 inches. Most preferably, L′ is about 3.5 inches. Insertion device 150 of decorative element 110 of the present invention has a length thickness T′ measured along line T′-T′. Preferably, T′ is between 0.0125 and 0.5 inches. Preferably, T′ is between 0.0575 and 0.25 inches. Most preferably, T′ is about 0.125 inches. Thickness T′ does not have to be uniform over length L′ of insertion device 150 .
[0028] Referring to FIG. 2, one preferred embodiment of insertion device 150 of decorative element 110 of the present invention includes second end 170 having a unitary insertion piece 174 . FIG. 1 shows unitary insertion piece 174 removably secured to pierceable object 12 . When insertion piece 174 is removably secured to pierceable object 12 , decorative element 110 can be positioned and repositioned as necessary to complete overall effect desired. Also, insertion device 150 optionally can include holes 250 that can be used in stitching decorative element (not shown) to insertion device 150 .
[0029] As shown in FIG. 1, one preferred embodiment of insertion device 50 of decorative element 10 of the present invention includes second end 70 having a plurality of prongs 76 . Prongs 76 are capable of being removably secured to pierceable object 12 and decorative element 10 can be repositioned as necessary to complete overall effect desired. Preferably, second end 70 has 2 to 6 prongs 76 . More preferably, second end 70 has 2 to 4 prongs 76 . Most preferably, second end 70 has 2 prongs 76 .
[0030] Referring to FIG. 4, in one preferred embodiment, insertion device 150 of decorative element 100 of the present invention is capable of being received into interior chamber 222 of decorative body 220 . In one embodiment, decorative body 220 further has an opening 224 for receiving insertion device 150 . Decorative body 120 is secured to insertion device 150 . While it is recognized that various methods can be used to secure decorative body 120 to insertion device 150 , gluing or stapling is preferred. Insertion device 150 can also be secured to decorative body 120 by designing opening 224 to have a width that is less than or equal to the width of proximal section 174 defined by line A′-A′, as shown in FIG. 2. As shown in FIG. 4, only distal section 172 of insertion device 150 protrudes from decorative body 120 . Proximal section 174 of second end 170 is secured within interior chamber 122 at a point where width of second end 170 along taper between distal section 172 and proximal section 74 is greater than width of opening 124 .
[0031] In one embodiment of decorative element 110 of the preferred invention, insertion device 150 is received by interior chamber 122 , as shown in FIG. 1. Insertion device 150 is attached to interior chamber 122 . As shown in FIG. 1A, glue 230 is located at an interface 232 between decorative body 120 and insertion device 150 at or near grasping portion 166 . Referring to FIG. 1B, in one of the embodiments of decorative element 110 of the present invention, a staple 234 secures decorative body 120 to insertion device 150 near or at grasping portion 166 . In addition to glue 230 or staple 234 , alternative means may be used to attach insertion device to decorative body, including fasteners or adhesives.
[0032] Referring to FIG. 5, one preferred embodiment of insertion device 150 of decorative element 210 of the present invention includes grasping section 162 for holding decorative element 210 during insertion into and removal from pierceable object 12 . Grasping section 160 is received into interior chamber 122 of decorative body 120 . Grasping section 160 further has reduced diameter portion 164 defining grasping portion 126 . In one embodiment of insertion device 150 of decorative element 210 of the present invention, grasping portion 124 is semi-circular.
[0033] The present invention also includes a method of removably securing decorative element 10 , 110 , 210 to pierceable object 12 . Referring to FIG. 6, one embodiment of the method of the present invention includes attachment and removal of decorative element 110 to and from pierceable object 12 , in this case a pumpkin. Attachment of decorative element 110 is accomplished by grasping decorative element 110 . During grasping, decorative body 120 is gathered around grasping portion 166 . Gathering decorative body 120 around grasping portion 166 minimizes shear forces between insertion device 150 and decorative body 120 during insertion and removal of second end 170 of insertion device 150 in pierceable object 12 . After grasping decorative element 110 , second end 170 of insertion device 150 is inserted at a suitable location on pierceable object 12 . Removal of decorative element 110 from pierceable object 12 is accomplished by grasping decorative element 110 by grasping portion 166 and removing second end 170 of insertion device 150 from pierceable body 12 .
[0034] In one embodiment of the present invention, pierceable object 12 is a pumpkin. Pierceable object 12 can also be a snowman or other object made from snow, a squash, a Styrofoam ball or object. Referring to FIG. 7, decorative element 310 is shown attached to a snowman 300 . Preferably, snowman 300 is made of snow or Styrofoam. In the embodiment shown, decorative element 310 represents an ear, although decorative element 310 can be shaped to represent a variety of features, including, but not limited to, hats, hair, eyes, nose, or mouth.
[0035] The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
|
A decorative element for use on a pierceable object such as a pumpkin is provided which includes a decorative body and an insertion device. The decorative body defines an interior chamber. The interior chamber receives and is attached to the insertion device. Preferably, the insertion device is attached to the interior chamber with glue.
A method for attaching and removing a decorative element to a pierceable object, including grasping the decorative element at a grasping section, positioning decorative element in a desired location on pierceable object and inserting the insertion device into the pierceable object. Decorative element is removed from pierceable object by grasping decorative element at grasping section and applying force sufficient to remove the insertion device from the pierceable object.
| 0
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit of U.S. Provisional Patent Application 60/440,532 filed Jan. 16, 2003.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] This invention relates to an improved pulper or mixer rotor with increased pumping and defibering capacities, reduced power requirements, easier maintenance and interchangeability of parts, and improved wear resistance.
[0004] 2. Description of Related Art
[0005] FIG. 1 shows a conventional pulping, mixing, or defibering apparatus, which generally includes a vat, or tub, 10 formed of side wall 11 and bottom wall 12 . In the center of the bottom wall 12 is a perforated bed-plate 13 . The bed-plate 13 permits draining of pulped paper stock, for example, after a pulping operation is completed. A rotor 15 for circulating the paper stock, for example, or other material, is mounted on a hub 14 in the center of the bed-plate 13 . Supports 19 stabilize the pulping tub, or vat, 10 .
[0006] The rotor 15 creates a mechanical shear and/or hydraulic shear effect on the pulp, or other material, being mixed. Mechanical shear, for example, is achieved by rotating the rotor 15 above the stationary bed-plate 13 so that the paper pulp stock, or other material, is agitated, and the fibers and liquids are approximately separated by being strained through the bed-plate 13 under the pressure applied by vanes 17 of the rotor 15 . Hydraulic shear, on the other hand, occurs by contacting the paper pulp fibers, for example, with other paper pulp fibers in the tub, or vat, 10 as a result of the turbulence, or flow pattern, generated by rotation of the rotor 15 . The rotor 15 is driven by gears that engage the hub 14 . A motor 22 powers the gears that are housed within gear housing 20 .
[0007] FIG. 2 shows a conventional pulper rotor 15 with a series of straight vanes 17 extending beyond the outer circumference of a spar ring 16 . The straight vanes 17 tend to be fairly blunt and thick at a leading vane face 17 a , and tapers thinner at a trailing edge 17 b of each vane 17 . One end of each vane 17 nearest the spar ring 16 joins an outer portion of the spar ring 16 . The portions where each vane 17 joins the spar ring 16 gradually tapers to form a gulley 17 c . These gulleys 17 c are susceptible to cavitation wear from the turbulent flow of pulp, or other materials passing over the vanes 17 in the wake of the agitation generated by rotation of the rotor 15 .
[0008] FIG. 3 shows that straight vanes 17 result in an angle of the leading edge of the vane face 17 a varying relative to a radian r n , for example, projecting from the rotor hub 14 to the edge of the vane face 17 a . As seen in FIG. 3 , for example, the angle of the vane face 17 a at a location nearest the spar ring 16 is 43 degrees relative to a radian r 1 projecting from the rotor hub 14 to a first edge location of the vane face 17 a , whereas the angle of the same vane face 17 a at an edge location furthest from the spar ring 16 is 30 degrees relative to a radian r2 similarly projecting from the rotor hub 14 to the edge of the vane face 17 a . As a result of the change in angle of the vane face 17 a , the vane face 17 a strikes the pulp material, or other material being mixed, less consistently and with less mixing or agitation effect because the relative angle of the vane face 17 a lessens as the vane 17 extends further from the spar ring 16 . That is to say, the pulp material, or other material being mixed by the vane 17 by striking the vane face 17 a , is less likely to be mixed with the same consistency or force by the straight vane 17 as the rotation of the rotor 15 occurs because the lessening relative angle of the vane face 17 a encourages the materials being mixed to simply slide along the vane face 17 a of each vane 17 and outward from the rotary path of the vanes 17 . Thus, the pulp, or other material being mixed, in conventional straight vane rotor systems tend to be ineffectively directed out of contact with the vane faces 17 a and out of the rotary path of vanes 17 , resulting in a more time-consuming mixing of the materials being required in order to achieve a desired defibering, for example, effect. The additional mixing time due to the inefficiencies of straight vane rotors requires additional power consumption to operate the rotor until the desired defibering effect on the materials is achieved.
[0009] Further, the bluntness of the leading edge of straight vane face 17 a subjects the vane faces 17 a to considerable wear as mixing of materials occurs. To compensate for the wear induced by the agitation of materials on the leading edge of straight vane faces 17 a , prefabricated wear plates are often separately welded onto the leading edge of the vanes 17 . Such straight vane face pulper rotors 15 with welded wear plates may be relatively easy to make, however, they tend to have some of the same inefficiencies at pumping materials in desired directions or capacities due, at least partially, to the changing relative angle of contact of each vane face 17 a with the pulp, or materials, being mixed as discussed above. Further, the requirement of welding wear plates onto the vanes 17 limits the materials that can be used to those compatible with the underlying material chosen for the vane. Such compatibility requirements may limit the choice of vane materials to those that are generally not the most wear-resistant type materials in order for the wear plates to be successfully welded onto the vanes. Still further, because of the welding aspect of the wear plate, it is often required to change the entire vane, at least, even when only the wear plate is all that is worn.
[0010] Moreover, straight vane face rotors can be difficult and economically inefficient to repair, replace or maintain. For example, often removal of the entire rotor is required in order to replace, repair or service just a vane or just a wear plate. The removal of an entire rotor may require additional personnel, and may result in significant inoperable time of the pulper, or mixer, in general.
[0011] To address the inefficiencies of straight vane face rotors, booster vanes 18 , as shown in FIG. 2 , are frequently used. Such booster vanes 18 are also typically welded to the top of the straight vanes 17 to add an additional material contacting face and to increase pumping efficiencies. The use of booster vanes 18 still does not render straight vane face rotors optimally efficient however, as the additional materials and production costs render such straight vane rotors 15 with booster vanes 18 more costly to manufacture. Further, even with booster vanes 18 , some materials are already directed away from the vanes 17 , in general, by the material's initial impact with the straight vane face 17 a as discussed above. Such booster vanes 18 also require increased power requirements to achieve increased pumping capacities. Thus, any pumping efficiency added by the booster vanes 18 may well be offset by the added manufacturing and added operational costs incurred with straight vane rotors having booster vanes 18 . Further, the introduction of yet another additional part, represented by the booster vane 18 , increases the costs and time required for maintenance, repair and/or replacement, while still experiencing the inconvenience of having to remove the entire rotor 15 to perform such repair, replacement or maintenance functions. Further still, such booster vanes 18 result in the gulleys 17 c being particularly susceptible to cavitation wear as a result of the increased turbulence of materials flowing in the wake of the booster vane 18 induced agitation of the pulp stock, or other material, being mixed.
[0012] As with the inefficiencies experienced by the changing angle of the vane face relative to the series of radians r n projecting from the rotor hub 14 , straight vanes 17 also have a varying intersection angle relative to the underlying bedplate 13 of the conventional pulper rotor 15 . The interface of the pulp stock, or other material, agitated by the vanes 17 of the rotor 15 and pressed downward toward the bedplate 13 results in the desired defibering, for example, of the pulp, or other materials, as the liquefied matter passes, as if strained, through apertures 13 a of the bedplate 13 (see FIG. 4 ). Thus, because the intersection angle of the vanes 17 , relative to the bedplate 13 , changes as the vanes 17 extend across the bedplate 13 , the pressure imposed upon the pulp stock, or other material, from the vanes 17 is not consistently applied to the materials from the inner diameter to the outer diameter of the bedplate 13 . As a result, defibering efficiency is less than optimal.
[0013] The inefficiencies of such straight vane rotors with respect to pumping and defibering inefficiencies, even with booster vanes, and the susceptibility of straight vane rotors to high wear zones and maintenance, repair or replacement inconveniences, pose problems the improved pulper, or mixer rotor, as set forth herein, is designed to help overcome. Further the power consumption inefficiencies of straight vane rotors may be minimized by the improved pulper, or mixer rotor described herein which helps eliminate the need for such booster vanes, and performs similar mixing of materials in less time, while requiring less power.
SUMMARY OF THE INVENTION
[0014] This invention provides an improved pulper, mixer or defibering, rotor having a spar ring attached to a hub of the rotor with a series of curved vanes projecting from the spar ring. The curved vanes have a constant vane face angle relative to radians immediately adjacent one another and extending outward from the hub of the rotor. As a result of the constant relative vane face angle, the pulp, or materials, mixed by the vanes of the rotor are more consistently in contact with the vanes during rotation of the rotor. Thus, booster vanes are not required. As a result, increased circulation and pumping effects with minimal power requirements are achieved.
[0015] This invention separately provides a series of curved vanes having vane faces with substantially similar, or preferably equal, surface volumes. As a result of the substantially similar, or preferably equal, vane face surface volumes, the paper pulp stock, or other materials, being mixed by the vanes in the pulper tub, or vat, remains in contact with the vane face of each vane for a prolonged period as circulation occurs.
[0016] This invention separately provides the series of curved vanes projecting from the spar ring as separately attachable to the spar ring via spar stubs. The spar stubs are made of a high strength material integral with the spar ring, whereas the separably attachable vanes are made with a highly wear-resistant material. As a result of the separably attachable nature of the vanes to the spar stubs, maintenance is easier as the vanes may be repaired or replaced without requiring removal of the entire rotor. Further because the vanes are separably attached, rather than welded, a greater variety of highly wear-resistant materials are available to form the vanes. As a result of the high strength spar ring and spar stubs, the need for additionally welded wear plates and/or booster vanes are not required, thus minimizing weight and power consumption. As a result of the highly wear-resistant material, the circulation and pumping effectiveness of the vanes and rotor continue longer, reducing the need for repair or replacement. As a further result of the separably attachable vanes, the opportunity to change configurations of the vanes to meet changing customer needs is also more readily available.
[0017] This invention separately provides vanes having an endplate feature that improve the tip suction pulse effect, which recirculates the paper pulp stock, or other material, more easily in the pulper tub, or vat, until the desired defibering, for example, is achieved.
[0018] These and other features and advantages of this invention area described in, or are apparent from, the following detailed description of various exemplary embodiments of the systems and methods according to this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Various exemplary embodiments of the systems and methods of this invention will be described in detail with reference to the following figures, wherein:
[0020] FIG. 1 illustrates a conventional pulper;
[0021] FIG. 2 illustrates a conventional straight vane faced rotor with booster vanes;
[0022] FIG. 3 illustrates a vane face angle of a conventional straight vane faced rotor relative to a radian originating from a rotor hub;
[0023] FIG. 4 illustrates an improved rotor mounted above a perforated bed-plate according to at least one exemplary embodiment of the invention;
[0024] FIG. 5 illustrates a bottom view of an exemplary embodiment of an improved rotor according to the invention;
[0025] FIG. 6 illustrates another embodiment showing a different mounting of the vane to a spar ring;
[0026] FIG. 7 illustrates an exemplary embodiment of a single vane according to the invention;
[0027] FIG. 8 illustrates a vane face angle of the improved rotor referred to in FIG. 4 relative to a radian originating from the rotor hub;
[0028] FIG. 9 illustrates another exemplary embodiment of a spar stub and vane according to the invention;
[0029] FIG. 10 is a schematic view of a composite vane in accordance with another embodiment of the invention; and
[0030] FIG. 11 is a schematic view of another vane structure.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0031] The conventional pulper tub, or vat, 10 shown in FIG. 1 shows generally the type of pulper tub, or vat, 10 with which the various exemplary embodiments of the improved pulper, mixing or defibering, rotor 35 of the invention described herein is intended to be used. Accordingly, like numerals are used, where possible, in describing the various exemplary embodiments of the invention when referring to features translatable with those of the conventional pulper of FIG. 1 .
[0032] FIG. 4 shows one exemplary embodiment of the improved pulper, mixer or defibering, rotor 35 of the invention. The pulper, mixer or defibering, rotor 35 includes a spar ring 36 that supports a plurality of vanes 37 . The vanes 37 extend generally radially outwardly from the spar ring 36 towards an outer circumference of the perforated bed-plate 13 . The spar ring 36 is mounted about a hub 14 at the center of the bed-plate 13 . The pulper, mixer or defibering, rotor 35 may be driven by a conventional gearing and motor 22 combination, as generally depicted in FIG. 1 . Rotation of the vanes 37 of the pulper, mixer or defibering, rotor causes paper pulp stock, for example, or other material, to circulate in the tub, or vat, 10 . The circulation of the stock, or other materials, helps achieve the hydraulic shearing effect among the circulating stock, or other materials, as well as the mechanical shearing effect on the stock, or other materials, via the interaction of the rotating vanes 37 against the stationary bed-plate 13 at a bottom of the pulper tub, or vat, 10 . Once the fibers of the paper pulp stock, or other material, are sufficiently broken down, or defibered, for example, the materials pass through apertures 13 a of the bed-plate 13 .
[0033] FIG. 5 illustrates the underside of an exemplary embodiment of the pulper, mixer or defibering, rotor 35 . The vanes 37 are demountably attachable to spar stubs 38 extending from the spar ring 36 . The spar stubs 38 may be made integrally with the spar ring 36 as shown in FIG. 5 . Alternatively, the spar stubs 38 may be separably attached, for example welded, to the spar ring 36 as shown in FIG. 4 . In any event, the spar stubs 38 project, at designated intervals, from an outer circumference of the spar ring 36 . The spar stubs 38 may be made of the same material as the spar ring 36 , or of a different material, in order to provide similar strength and a high degree stability between the spar stubs 38 and spar ring 36 .
[0034] The spar stubs 38 , of the exemplary embodiment shown in FIG. 5 , include attachment devices 39 for securing the vanes 37 to the spar stubs 38 . The attachment devices may be any of screws, rivets, projections, or other such structures for securing the vanes 37 to the spar stubs 38 . It is noted that those skilled in the art may fashion other coupling arrangements besides the projection/spar stubs 38 that may be received in female grooves or the like shown. For example, the vanes 37 could be designed to have male projections on their i.d. ends adapted for receipt in female concavities provided in appropriate locations on the spar ring 36 . One such alternative coupling design is shown in FIG. 6 . Here, specifically configured female slots 100 are provided around the periphery of spar ring 36 . Mating male ends 102 of the vanes 37 are snugly fitted in the slots and the joint can be further secured by bolts or the like (not shown) that would be inserted through registered bores 104 , 106 placed respectively in the female and male parts, and corresponding apertures 108 of the clamp ring 110 . A rotor cap 112 is attached over the assembly to secure to the clamp ring.
[0035] FIG. 7 illustrates an exemplary embodiment of a vane 37 . The vane 37 is separably attachable to the spar stubs by attachment devices 40 corresponding to the attachment devices of the spar stubs. Each vane 37 includes a vane face 37 a on the leading edge, a trailing edge 37 b and a spar stub mounting surface 37 c . The vane face 37 a is provided with a designated vane height h1. The vane height h1 at the vane face 37 a tapers to a vane height h2 at the trailing edge 37 b of the vane 37 . The pitch angle of the vane face 37 a is preferably constant, for example at 30°, to provide a desired pressure to the paper pulp stock, or other materials, being mixed by contact with the vane face 37 a of the vane 37 upon rotation. The vane 37 may be slid onto the spar stub 38 (see FIG. 5 ) in order to align the spar stub mounting surface 37 c of the vane 37 so that the corresponding attachment devices are aligned to secure the vane 37 to the spar stub 38 , and the innermost vane surface 37 d abuts the spar ring 36 ( FIG. 4 ). The outermost vane surface 37 e of the vane 37 is generally curved from the vane face 37 a to the trailing edge 37 b . The interface of the trailing edge 37 b and outermost vane surface 37 e of the vane 37 provides a lifting effect that sucks fiber off from the stock, or other materials, being mixed by rotation of the rotor 35 . Note also in FIG. 7 that the trailing edge of the vane comprises a curved edge 116 radiused downwardly toward the bed-plate surface. This too helps to provide a suction pulse that cleans the bed-plate. Further protruding end dam member 114 is provided along the o.d. extremity of the trailing edge. The end dam doesn't allow flow to “leak” off the end of the rotor; thereby improving suction and bed-plate cleaning across the entire swept area.
[0036] FIG. 8 shows generally, according to the various exemplary embodiments of the invention, a configuration of the vanes 37 mounted to the spar ring 36 by attachment devices 40 . The vanes 37 are mounted such that the angle between the vane face 37 a and a radian r 1 extending from the center of the hub 14 towards the outermost circumference of the spar ring 36 is substantially the same as the angle between the vane face 37 a and any other radian, for example r 2 , similarly extending from the center of the hub 14 and toward the outermost circumference of the spar ring 36 or the outermost vane surface 37 e . By substantially the same we mean that the difference in vane face surface to intersecting radian angle for any two points along the vane face surface should not exceed greater than about 10°. By controlling the angle of the vane face 37 a relative to the spar ring 36 , more constant contact of the paper pulp stock, or other materials, being mixed is achieved upon rotation of the rotor 35 and vanes 37 . Further, because the vanes 37 may be separably attached to the spar ring 36 by mounting to the spar stubs 38 ( FIG. 5 ), the vanes 37 may be made of a greater variety of materials, such as ceramics, urethanes, or other highly wear resistant and durable materials that previous straight vane faced rotors, for example, were not able to be made of.
[0037] Of course, it should be appreciated that the angles of each of the vane faces 37 a are not limited to uniformity, rather, the angle of the vane face 37 a of each vane may be varied to accomplish the desired contact with the stock, or other materials, being mixed. Likewise, the contour or shape of the vanes 37 may be varied even though mounted on the same spar ring 36 , such that one vane 37 may be smooth, and another vane 37 may be toothed, for example, or otherwise not smooth, in order to achieve different pulping, mixing or defibering, actions. Similarly, vanes 37 of different lengths may be mounted on the same spar ring 36 to achieve different pulping, mixing or defibering, actions as well.
[0038] Certain advantages of the various exemplary embodiments of the rotor 35 using the separably mounted vanes 37 of the invention versus standard, or conventional, rotors may occur. For example, the various exemplary embodiments of the rotor 35 and vanes 37 will achieve the same thrust (Th) using significantly less horsepower (hp) than standard, or conventional, rotors. As a result, not only will more stock, or other materials, be in contact with the vane face 37 a of the vanes 37 , as described with reference to FIG. 7 , for example, but the efficiency of the pulping, mixing or defibering will be increased as well while less power will be used as evidenced by higher thrust/horsepower ratios (Th/hp) than conventional designs. Additionally, a greater volume, or quantity, of stock, or other materials, may be pulped, mixed or defibered per unit time (sec) as would be evidenced by the quantity to time ratio (Q).
[0039] Thus, not only are the various exemplary embodiments of the separably attached vanes more efficient, they also are more durable and wear resistant due to the choice of materials available to comprise each vane 37 . Moreover, even were replacement or repair of the vanes 37 required, such replacement or repair is relatively easy as the rotor 35 may be left in the pulper tub, or vat, 10 , for example, whereas prior art conventional rotors require the complete removal of the rotor in order to work only on the vanes, or other vane related components, for example.
[0040] FIG. 9 illustrates another exemplary embodiment of the vanes 47 according to the invention. The vanes 47 , according to the exemplary embodiment shown in FIG. 10 differ from the vanes 37 shown in FIG. 7 , which illustrate vanes 37 having a continuous trailing edge 37 b extending from the innermost vane surface 37 d to the outermost vane surface 37 e and integral with each vane 37 . As a result, the vanes 37 are mounted by sliding over the spar stubs 38 , in a generally perpendicular direction relative to the spar ring 36 , towards the spar ring 36 . The exemplary embodiment of the vanes 47 shown in FIG. 9 , on the other hand, provides spar stubs 48 joined at one end to the spar ring 36 and having an outer end 48 a opposite the spar ring 36 . Each spar stub includes a first trailing edge portion 48 b extending from the spar ring 36 to an outer end 48 a of the spar stub 48 .
[0041] A vane 47 having a vane face 47 a and a second trailing edge portion 47 b is slidingly mounted over each spar stub 48 , in a generally lateral direction relative to the spar ring 36 , such that the first trailing edge portion 48 b of the spar stub 48 , and the second trailing edge portion 47 b of the vane 47 , are immediately adjacent one another to form the equivalent of the unified trailing edge 37 b of the exemplary embodiment described with reference to FIG. 7 above. Once aligned appropriately over the spar stub 48 , the vane 47 is attached to the spar stub 48 in a manner as described with reference to the exemplary embodiments discussed above.
[0042] The vanes 47 of the exemplary embodiment illustrated in FIG. 9 have vane faces 47 a of a constant pitch angle such that the stock, or other materials, being mixed are more readily contacted by the vane face 47 a as the rotor 35 and vanes 47 rotate. Likewise, the vane 47 tapers from a height h1 at the vane face 47 a to a height h2 at the combined trailing edge formed of first trailing edge portion 48 b and second trailing edge portion 47 b.
[0043] The vanes 47 thus provide similar advantages to those described with reference to the exemplary embodiments discussed above. Such advantages include the greater choice of materials to form the vanes 47 , more flexibility in the arrangement of vanes 47 on the spar ring 36 , greater contact area and contact time of the materials being mixed with the vane face 47 a , decreased power requirements, and easier accessibility for maintenance and repair of the vanes 47 .
[0044] An alternative vane structure is shown in FIG. 10 . Here, the face 37 a of the vane comprises a wear plate 118 made of a hard metal that is, for example, investment cast to the desired shape. The trailing body section 214 of the vane may be formed from a filler/bonding material. As shown, spar stub 38 is partially in phantom and includes a male mounting end 116 adapted for reception in a female recess or the like in the spar ring (not shown). The body section 214 may hold the face plate and spar stub 38 together and provide the required hydraulic profile. Body section 214 may be composed of an urethane/epoxy but could also be a bi-metal cast process.
[0045] FIG. 11 illustrates another unique aspect of the invention. Here, the id. surface of the vane is shown at 140 with the o.d. surface depicted as 142 . One inner length of the vane shown at 150 is shorter than an outer vane length shown at 152 . The vane length in this embodiment increases progressively from inner vane location toward outer vane location. In operation, this vane length/section increases as the peripheral shield of the vane location increases to improve performance and reduce drag.
[0046] It is apparent that the vane member shown in FIG. 11 is streamlined to enhance operational performance. The vane member is adapted for radial disposition on a hub or the like in a pulp and paper apparatus. The vane member is rotatable around a central axis that extends through the hub and the vane has an inner-end adapted for positioning adjacent to the hub at an opposing outer edge at an outer radially directed extremity of the vane. The vane comprises a leading edge 190 and a trailing edge 192 . The vane lengths are shown at 150 and 152 and they are defined as the distance between the leading edge and the trailing edge at given points along a continuum 160 that extends in the radial direction from the inner-end of the vane to the outer-end. In accordance with this aspect of the invention, the vane length increases as one proceeds along the continuum from the inner-end to the outer-end.
[0047] In operation, with any of the exemplary embodiments of the improved pulper, or mixer, rotor 35 described herein, including the spar ring 36 , spar stubs 38 or 48 , and vanes 37 or 47 , paper pulp stock, or other material, is placed into the pulper tub, or vat, 10 . The motor 22 is then operated to drive the gear 20 . The gear 20 engages the hub 14 , to which rotor 35 is mounted. The rotation of the rotor 35 therefore causes the vanes 37 or 47 to rotate in a direction such that the vane face 37 a or 47 a contacts the stock, or materials, initially. As rotation of the rotor 35 and vanes 37 a or 47 a occurs, more consistent contact of the stock, or materials, with the vane face 37 a or 47 a is maintained resulting in increased agitation and mixing of the materials. In addition, the trailing edge 37 b , or the combined first trailing edge portion 48 b of the spar stub 48 with the second trailing edge portion 47 b of the vane, helps lift fibers, for example, from the stock, or materials, being mixed such that defibering is achieved. The defibered materials, for example, are then passed through the apertures 13 a ( FIG. 4 ) in the bed-plate 13 underlying the rotor 35 at the bottom of the tub, or vat, 10 .
[0048] In summary, one aspect of the invention is directed toward the combination of demountable vane members that are adapted to be mounted over and carried by the spar stubs with the spar stubs being fixed to the annular spar ring by welding or the like. The demountable vanes may be composed of any one or more of a variety of wear resistant materials such as for example, wear resistant initial such as “stellite”, cast cobalt alloys, polyurethanes, even ceramic materials.
[0049] In another aspect of the invention, each of the leading surfaces of the vanes presents a substantially constant angle relative to at least two radians that extend from the rotor axis to any two points located along that leading cage. By “substantially constant”, we mean that this angle should not vary by more than about 10°. It is generally desirable than this angle, as measured between the axis and to a point or tangent along the leading edge should be between about 10° to about 60°, preferably about 300 to about 40°. In many cases, it will be advantageous if each of the vanes (and their corresponding leading edges) possesses this same leading edge angle.
[0050] While the invention has been described with reference to the exemplary embodiments set forth herein, it should be appreciated that other alternatives, combinations, modifications and variations are apparent to those skilled in the art. Accordingly, the preferred embodiments of this invention, as set forth above, are intended to be illustrative only, and not limiting. Various changes can be made without departing from the spirit and scope of this invention.
|
An improved pulper, mixer or defibering, rotor having a spar ring attached to a hub of the rotor with a series of curved vanes projecting from the spar ring. The curved vanes have a vane face and a trailing edge. The trailing edge may be unitary and integral with the vane, or may be segmented in combination with trailing edge portion provided on an underlying spar stub to which the vanes are attached. The hydrodynamic suction created by the trailing edge is enhanced by the addition of a dam at the vane tip end of the trailing edge zone. The vanes have a constant vane face angle relative to radians extending outward from the hub of the rotor. As a result of the constant vane face angle the pulp, or other materials, mixed by the vanes during rotation of the rotor are more consistently in contact with the vanes during rotation of the rotor. The vanes are also streamlined to reduce hydrodynamic drag especially at the vane tips where speed and therefore drag potential are at their highest levels. As a result, increased circulation and pumping effects with minimal power requirements are achieved. The vanes may be made of high wear resistant materials and are easily accessible for maintenance, repair or replacement.
| 3
|
RELATED APPLICATIONS
Benefit is claimed under 35 U.S.C. 119(e) to U.S. Provisional Application Ser. No. 60/553,087, entitled “Approach for representing business architecture for information systems” by Sundararajan et al., filed Mar. 15, 2004, which is herein incorporated in its entirety by reference for all purposes.
Benefit is also claimed under 35 U.S.C. 119(e) to U.S. Provisional Application Ser. No. 60/553,256, “Approach for representing technical architecture” by Sundararajan et al., filed Mar. 15, 2004, which is incorporated herein by reference for all purposes.
Benefit is also claimed under 35 U.S.C. 119(e) to U.S. Provisional Application Ser. No. 60/553,352, “Mapping business and technical architecture elements to implementation technologies” by Sundararajan et al., filed Mar. 15, 2004, which is incorporated herein by reference for all purposes.
Benefit is also claimed under 35 U.S.C. 119(e) to U.S. Provisional Application Ser. No. 60/553,470, “Schema for storing integrated software specification” by Sundararajan et al., filed Mar. 16, 2004, which is incorporated herein by reference for all purposes.
Benefit is also claimed under 35 U.S.C. 119(e) to U.S. Provisional Application Ser. No. 60/553,251, “Software cycle availability over the internet” by Sundararajan et al., filed Mar. 15, 2004, which is incorporated herein by reference for all purposes.
Benefit is also claimed under 35 U.S.C. 119(e) to U.S. Provisional Application Ser. No. 60/553,584, “Dynamic outsourcing of software development and delivery using the internet” by Sundararajan et al., filed Mar. 16, 2004, which is incorporated herein by reference for all purposes.
FIELD OF THE INVENTION
This invention relates to the field of software engineering, and more specifically to a method and apparatus to structure, store, and manage specifications gathered during various phases of an information system's life cycle.
BACKGROUND OF THE INVENTION
There have been many software engineering aids and ideas that attempted to solve the issue of structuring, storing and managing specifications created during the different phases of software lifecycle. Recently, some approaches have appeared to create an integrated approach for managing software lifecycle by integrating these islands. All these approaches suffer from the following issues: difficulty in defining standard elements to model the information captured in these various phases, difficulty in understanding the relationship between these elements while implementing the various phases, and difficulty in creating an integrated process around a central model.
Issues arise due to the fact that the representation of specifications captured across these stages need a common thread or translation semantics. Since diagram elements are varied even in a single phase and view and usage of such elements are also varied, evolving a common data model has never been achieved. The difficulty is compounded by the fact that the various classes of information systems specified (e.g., business systems and real-time systems) require different representation mechanisms owing to the differences in implementation interpretation. Conventional attempts end up as patchwork of various aids integrated poorly.
Other requirements that need to be addressed in the current approach include the peripheral activities in the software lifecycle. These relate to configuration management, analyzing impact of changes to be made, project-management-related activities dealing with estimation, planning and control and rolling out the product and creating access profile. This requires standardized work product structure and the relations between the various elements of the work product. Lack of an integrated representation of the product structure severely affects the ability to perform all the related activities in the context of the work product.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing software services delivery over the Internet.
FIG. 2 is a schema 100 for gathering requirements and engineering enterprise software.
FIG. 3 is a chart 200 of levels used in schema 100 for engineering the enterprise software.
FIG. 4 is a schematic block diagram 300 of an exemplary information-processing system that can be used in conjunction with various embodiments of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
Requirements Management:
In conventional approaches to large software system development, business analysts do not have a set of standard elements with which they can define the business architecture suitable for implementing information systems. Business processes are generally represented using “event-process chains,” where functions or activities performed across the organization in the various organization units are depicted as a chain of nodes connected by event that trigger them. This approach enables business users to understand the process flows. There are no clear methodologies to create such process chains, and the levels of refinement are confusing. Moreover, this approach is complicated by the fact that there are no clear semantics as to how these specifications translate into information systems to be created to support such process flows.
Alternatively, ‘use cases’ are sometimes used to depict such flows where an “actor” interacts with the system in a specific manner to accomplish the tasks. This approach also suffers from lack of clear methodology on what details should be made available in these use cases. Further, semantics of translating these specifications into information-systems design are also missing.
Engineering
The deficiency in conventional approaches is a lack of a clear set of elements with which a proposed technical architecture is specified, irrespective of technology choices. Even though existing approaches do create a formalism by splitting the general characteristics of systems in terms of presentation, logic-handling and data-persistence layers, it is not complete since these are conceptual elements again related to technologies, rather than requirements of a specification formalism that is independent of technology. What is not laid out is a clear set of elements that an architect should use to instruct the designers on how to proceed with designing under the architectural guidelines. This leads to violations of the guidelines during design and implementation, leading to either rework during development phase or costly repairs after implementation.
Software Construction
Conventional practices in implementing software design suffer from a lack of standard elements to express the requirements and design specification, and a lack of flexible technology-artifact mapping to deliver the specification in chosen technologies. An “artifact” is a type of deliverable that is part of a developed application installed in a particular hardware. Examples of artifacts are .DLL (Dynamic Link Library) files, .exe files, .htm files, and database scripts.
Software Services Delivery Platform
FIG. 1 shows software services delivery over the Internet. FIG. 1 shows software services delivery platform 100 , software services providers 130 , and software services consumers 110 and 120 interacting over one or more media, which may include the internet 140 or other medium 142 .
Using software services delivery platform 100 , software services providers 130 can provide software solutions (or products) 150 , 160 to software services consumers such as consumers 110 and 120 , over the internet. The software solutions or products thus provided, may or may not use the internet and may differ in their technical architectures and technology components they use. As shown in FIG. 1 , software solutions 150 and 160 are exemplary representations of solution or product varieties which a software services consumer may want and get (from the software services providers) to conduct their business.
Software services delivery platform 100 includes web-enabled provider interface 102 , schema 104 , and code generators (CG) 106 and 108 . In some embodiments, schema 104 is a structured embodiment of all the necessary and sufficient details that are used to enable automatic (or manual) production and deployment of the software solution or product. Schema 104 may hold structured specification data which enables consistent delivery of high-quality software solutions or products for a preferred technical architecture and technology components. The schema as a holding entity of all the specification data makes possible any analysis to study the probable impact of any proposed change(s) to the software solution or product. Example embodiments of schema 104 are described below with reference to FIG. 2 .
In some embodiments, software service providers may utilize software services delivery platform 100 to specify, generate, and deliver software to consumers. Further, in some embodiments, software services delivery platform 100 may be utilized to maintain the software solution over its life cycle. For example, a software services provider may maintain a software solution over its life cycle by interacting with software services delivery platform 100 .
A software services provider may obtain business requirements from a software services consumer, and then populate schema 104 in software services delivery platform 100 . For example, in some embodiments, a software services provider may provide solution specification data (SSD) over the Internet using web-enabled provider interface 102 .
As shown in FIG. 1 , a software solution developed using software services delivery platform 100 may include its own schema, as well as its own interfaces. In some embodiments, software services delivery platform 100 may be used to develop a software product with a web-enabled interface, such as software solution 160 , and in other embodiments, software services delivery platform 100 may be used to develop a software product without a web-enabled interface, such as software solution 150 .
Software services delivery platform 100 and software solutions 150 , 160 are essentially different elements. The former is a tool to produce a product, while the latter is the product. It is pertinent to note that in some embodiments, the schema of software services delivery platform 100 is entirely different from the schema(s) of the software solutions (or products).
Web-enabled provider interface 102 includes a visual manifestation of the process and methodology by which the software services providers fill up the schema of the software services delivery platform with the necessary and sufficient data required to produce the software solution or product. Web-enabled provider interface 102 is a standard and consistent mechanism made available over the Internet for dispersed software services providers to fill up the schema. The mechanism includes checks and balances to ensure integrity of data being filled up.
As described above, web-enabled provider interface 102 included in software services delivery platform 100 is different from any web-enabled consumer interface that may be included in software solution, such as web-enabled consumer interface 162 included in software solution 160 . Consequently, in some embodiments, web-enabled provider interface 102 may not be alterable by software services providers, whereas web-enabled consumer interfaces in software solutions 150 and 160 may be alterable by software services providers by changing data held in schema 104 .
Code generators 106 and 108 are components which automate the production of the software programs which collectively constitute the software solutions or products 150 , 160 . Code generators 106 and 108 make use of the data available in schema 104 of software services delivery platform 100 to produce software solutions 150 and 160 . In some embodiments, manual intervention for the production of software programs (also known as “source code”) is reduced through the use of code generators 106 and 108 and the manner in which they are structured. By reducing the manual intervention, code generators 106 and 108 seek to produce consistent and repeatable high-quality software programs (codes) for any preferred technical architecture and technology.
The internet is the medium by which the software services consumer and software services providers collaborate to develop and deploy the software solution or product. The internet minimizes the need for a specific co-location of the software services consumer and the software services providers. In other words, various embodiments of the invention utilize the internet to greatly reduce the interference of geographical dispersion of software services consumer and software services providers, on the work distribution and delivery process of software solutions or products.
The data which a software services consumer provides through the web-enabled consumer interface (or any other interface) included in the software solution or the product, is very different from the data which is provided by the software services providers, through the web-enabled interface(s) included in the software services delivery platform. The former set of data, referred to as Business Transaction Data (BTD), pertains to a specific business of the software services consumer while, the latter set of data, referred to as Solution (or product) Specification Data (SSD), pertains to the production of software solutions (or products) by the software services providers.
Software services providers and consumers are shown interacting at 132 in FIG. 1 . This interaction produces information from which the software services providers obtain the necessary and sufficient data to fill into schema 104 of software services delivery platform 100 .
Schema 104 provides for representing a process that is to be implemented for execution by a computer system. The schema provides a high level of abstraction in the form of a business functions level that provides flexibility in identifying functions to be performed in an organization independently of implementation options. The schema is used to represent these business functions as rows in a relational database table with attributes of the functions. The syntax of textual descriptions of the business functions in the rows is flexible, allowing easy understanding by members of the organization, such as a business group. In one embodiment, the syntax is driven by the semantics of the business or method to be automated by the computer system. A layered approach is used to convert the high level of abstraction into actual code for execution by the computer system.
In some embodiments, standard elements and the interrelationships form the backbone of a formal schema for storing the product structure evolved during the different phases of the software lifecycle. The schema allows for persisting these structures in any standard database system to be accessed using a web-enabled provider interface. All the operational activities during software life cycle are driven with these structures. Recording of the peripheral activities are created as adornments to this backbone structure.
Representing Business Architecture for Information Systems
In some embodiments, the invention includes a method that includes: (1) using a layered approach to defining business architecture irrespective of implementation options, (2) creating standard architectural elements in each of these layers, and (3) using standard structural connective elements to enable “persisting” the specification objects to aid in generating and maintaining the software throughout the complete system lifecycle. Further, in some embodiments, the invention includes web-enabled interfaces that allow geographically dispersed software services providers to interact with the schema of the software services delivery platform.
In some embodiments, the invention's application and business architecture is defined in the following five elements: (A) the business functions performed in an organization, (B) the activities performed inside a business function in response to happenings within and from outside the system, (C) the user interfaces used as a set to complete each of activities to capture and retrieve information, (D) the tasks or actions performed to fill, persist and retrieve various elements on the user interfaces, and (E) the business rules that govern each of such tasks.
Each of the five elements is represented by a data structure (in some embodiments these are, for example, five interrelated portions of a single larger data structure), into which data regarding requirements is entered. The data structure, such as a row in a relational database, also contains other information such as due dates, programmer responsible, cost budgets, size, performance, and other attributes useful for producing enterprise software. This data is formulated, constrained, and formatted in such a way as to make programming, testing, planning, and managing easy to do.
Further example attributes include attributes for user interfaces, such as whether to use buttons, radio dials, fields, etc. Attributes for activities may include whether the activity is system or user initiated. A user initiated activity might appear as a menu item, but not appear as a menu item if it is a system initiated activity. A function might be an external function, in which case it might be interfaced to another system for implementation of the function itself. These are just a very few examples of attributes that may be collected to help in producing enterprise software. The attributes are formulated to provide constraints, and to make planning and managing of implementation of the software easy to do. Others will be apparent to those of skill in the art, and may also be dependent on the type processes being specified.
The requirements gathered from one or more business analysts (experts who understand the needs of the business organization) are constrained to a particular format suitable for entry into a data structure.
The standard architectural elements of such an approach, which correspond to the above five elements, then are (a) Business functions, (b) Business activities, (c) User interfaces or forms, (d) Tasks or actions performed on the user interface, and (e) Business rules.
FIG. 2 is a schema 104 for gathering requirements and for creating and managing enterprise software from the gathered requirements. Schema 104 includes multiple levels of abstraction of requirements. The first level 202 is an application or business architecture level. This level is used to define the high level requirements in context relevant syntax. The levels are stored in a database schema form in one embodiment, such that lower levels, progressing toward actual coding are linked to high levels. A second level 204 is used to represent a technical or design architecture of the first level. It serves as an intermediate link between the first level and a third level 206 represents the actual building blocks and technology specific customization.
The first level is a process expression level. It includes a plurality of elements or units, each of which stores various aspects of specifications derived from the requirements and software built to those specifications. In some embodiments, schema level 202 includes business processes 211 that define the requirements at a level compatible with the thinking processes of business-requirements experts. In some embodiments, business processes 211 are divided into a first five units including business functions 212 , business activities 213 , user interfaces 214 , actions 215 , and business rules 216 .
An example of a business process might be sales order processing for a business. Business functions 212 would include purchase requisitioning, approval and purchase order dispatch. Business activities might include an acknowledgement, get best quote, release purchase order. User interfaces may be defined in terms of show all pending purchase orders for approval, an approval screen, and others. Actions may include things like fetch next purchase order for approval, link to next page, send acknowledgement, or send rejection.
Business rules might include things link “if no request, tell user x”. As can be seen, the first level 202 contains a textual description of the business or other process to be implemented by a computer system or otherwise electronically. The descriptions take the form of text that is very relevant to one who is designing the business process. In one sense, it is an abstract representation of the actual code that will be written, but in another sense, it separates the structure of the implementation from the expression of the process.
Business processes 211 and their associated events 221 represent the operational flow across the organization for which the software is being developed. Events 221 , in the form of entry and exit events to the constituent functions, activities, and interfaces are connectors that define flow of control or interfaces between other units. Business activities and their associated events represent the operational flow across a unit within the organization. User interfaces 214 and their associated events 221 represent the specified interface map for the systems and software being developed.
Links 222 are formed from mapping of events 221 that represent interconnections, or from user interfaces 234 . Integration services 223 are formed from mapping of events 221 , business rules 216 , or methods 236 . A second five units represent the design architecture 204 , and include, in some embodiments, components 231 that represent the basic software units of this approach, entry points 232 , user interfaces 233 , services 233 , and methods 235 . In some embodiments, each one of the first five units is mapped to a corresponding one of the second five units, e.g., business functions 212 are mapped to components 231 , business activities 213 are mapped to entry points 232 , user interfaces 214 are mapped to user interfaces 233 , action 215 are mapped to services 234 , and business rules 216 are mapped to methods 235 . In some embodiments, error conditions 236 are provided for methods 235 .
In some embodiments, the third level 206 contains building blocks and customization. Data structure artifacts 241 are generated from the events 221 and the components 231 , user-interface artifacts 242 are generated from the entry points 232 and the user interfaces 233 of the second five units, and application service artifacts 243 are generated from the services 234 and the methods 235 . In some embodiments, application service artifacts 243 are also generated from integration services 223 and error conditions 236 .
FIG. 3 represents connections within and across levels, which are used as the software is being developed and engineered.
The first level corresponding to level 202 in FIG. 2 in the diagram creates a process flow by depicting entry events and exit events to the constituent functions from/to other functions in the same process or across processes. The standard connective elements (which connect the standard architectural elements) are events that are triggered by and/or handled by the various architectural elements (FEnl, FExl, AEnl, AExl, UEnl, UExl) FEnI represents an entry event handled by function 1 . FExl is an exit event generated by function 1 . AEnl is an entry event handled by activity 1 . Events are represented by ovals in FIG. 3 . AExl is an exit event generated by activity 1 . UEnl is an entry event handled by User Interface 1 . UExl is an exit event generated by User Interface 1 .
The second level 204 for activity flow uses the entry event for the corresponding functions as the start event to create the set of activities and interactions thru events to reach the end events for the function. Each activity node 305 , 315 , and 320 is expanded along the same principles to depict the User Interface (UI) flow needed to complete the activity. The next level 206 represents tasks at task nodes 325 , 330 and 335 on the UI and subsequently the business rules to be implemented for the tasks expanded. Events are again represented by ovals.
This approach creates a complete map of the system behavior up to the business rules/policies level and will be the driver for engaging with customers for whom the code is being written. The nodes translate to relevant nodes in engineering. The events that connect them are classified and translated to information-exchange events (these are implemented as UI look ups, and Data Look ups at the SP level for performing the validations), and transfer-of-control events (these are implemented as integration services across component boundaries and data updates or access across boundaries for local storage inside the component boundary).
Events are now described with respect to an example business process in FIG. 3 . An event is a stimulus that triggers a function/activity/user interface. The function/activity/user interface responds to the stimulus and results in an outcome. The stimulus is referred to as an entry event and the outcome as an exit event. An example of an entry event at the function level is “Employee initiates leave request.” The function that responds to this stimulus is a leave-management business function. An example of an exit event is “Employee leave request approved/rejected.” UI lookups are user interfaces provided to look up certain reference information in the course of completing a transaction. For example, during the processing of a leave authorization the supervisor could look up the leave balance of the employee. Data lookup is the reference information used to validate data in the database. An example of such lookup is the validation of employee eligibility for the type of leave applied for. Stored-procedure-level look up is used where multiple business rules need to be implemented in a common environment.
An event within the system querying for information is an information-exchange event, e.g., checking an available-to-promise date from a production schedule, or checking on vendor rating for a purchase order creation. A transfer-of-control event is an event within the system that transfers information and control to the next function in a business process, e.g., items ready for packing to be handled by the packing function, or invoice to be raised for item purchased to be handled by accounts payable.
The mapping of the nodes and events to the underlying engineering models complete the packaging and prepares for implementation. For new solutions, mapping is the analysis effort of deciding on the implementation mode for the events with the nodes already defined. Impact analyses or changes will be recorded as a set of events that need to be added or deleted or enhanced in terms of the information content. The mapping information will be used to create the traced impact on the engineering model elements affected and will form the basis for the changes to be engineered into an existing solution. This component initiates the changes at the process-function level and can go in-depth until the business rules are implemented inside the software.
For a typical application, changes that can impact events at the process and/or activity level provide information for probing impact at the levels below. There can be changes which attribute to the flow and the node in specific. The specification of this attribute provides the connectors to be involved at both ends in an event-managed impact analysis. Subscription and publishing of the information is affected in this impact.
The user has the option of taking up the impacted change provided as side impact, or ignore the suggested changes, based on his ability to assess the impact. An example of impact at the activity level would be flow change. This change flow will result in User Interface(s) that may have addition or deletion of controls/elements in the presentation and subsequent use of the data from these controls/elements in the processing area. So if it impacts the processing further down, the impact is identified by its engineering nodes that need modification. Implementation using business logic will change to accommodate this accepted/suggested modification.
In a case where the leave-management function interacts with the employee-handling function, there could be a change envisaged that the employee eligibility for different leaves is based on employee type. This leads to a change in the signature of the IE event connecting leave management and employee handling. This change in the event at the function interaction level is used to find the possible impact at other levels based on the mapping of this information exchange event at a function level to its implementation details and also to the events at activity, user-interface levels. This could lead to a change in the data exchange between the two use interfaces and also change in the service signature of the leave eligibility service.
The following advantages may result: a single context relevant diagram/syntax may be used for representing a business architecture. Its formal structure provides for persisting the business-architecture specification. Persistence is the storing of the specifications in a data base system so that it could be used by others at any other point in time. This results in a persistent blueprint for driving software engineering and the roll out of the finished information systems. It also allows business-impact analysis and implementation independence.
Representing Technical Architecture
In the approach of the present invention, the technical architecture is specified using the following standard elements: a “component,” which, as an architecture element, corresponds to an individual part of a system (for example, the leave-management component).
Components include System Entry Points, Business Objects, Services, Process Sections, Methods, Links, Integration Services, and Interface Business Objects.
The “system entry points” are visual-interface elements, for example, menu items for leave request, leave authorization, etc.
The “business-objects” element deals with the need to store and persist information structures. An example of a business object is the data structure that holds employee information, company policies, leave eligibilities etc.
The “services” element represents the interface structure to interact with the data structures to store and retrieve persisted information.
The “process-sections” elements represent the flow of logic needed to handle a service request.
The “methods” elements are individual logical elements that are invoked during service-request handling directed by the process section specifications, for example, the service for a leave request could trigger methods for employee validations, leave-eligibility validations, etc., whose execution sequence is controlled by the process section.
The “links” elements are a type of interaction element between two visual-interface elements of the system. For example, the UI look up for leave availability from leave authorization screen.
The “integration services” elements are a type of interaction between two components of the system. An example of integration service is posting of leave information to payroll for pay computation.
The “interface business objects” elements are a type interaction between two components of the system. An example of this is employee name lookup based on the employee code.
These elements provide a comprehensive set for some embodiments, sufficient to enable the engineers to design the system without violating the architectural guidelines. Interpretation of these architecture elements varies and is based upon the technology choices made for implementation. In fact, technology choices are imposed on the design specifications using these architectural elements only during implementation.
This provides the following advantages: design engineers, by using this approach, are presented with a clear set of architectural elements for specification. The approach does not require the designers to consider technology choices during development phase. Since the elements are not technology dependent, implementers could be instructed on specific implementation approach based on technology choices against each of the elements designed.
Mapping Business and Technical Architecture Elements to Implementation Technologies
Various embodiments of the present invention address the following problem: given a set of requirements and technical-design elements, how do designers and implementers apply choices within the architectural guidelines to arrive at the implementation approach?
In some embodiments of the present invention, the requirements specification elements include business functions, business activities, user interfaces or forms, tasks or actions performed on the user interface, business rules and events
(which connect the other five elements.)
Design-specification elements may include components, system entry points, business objects, services, process section, methods, links, integration services and interface business objects.
For example, in some embodiments, a sample technology implementation architecture in Microsoft technology set will be (A) Presentation supported by internet pages and the web server, (B) Business logic supported by middle-tier transaction-enabled COM objects, (C) Database layer supported by SQL server RDBMS, and (D) Packaging as COM+ packages for each subsystem.
In some embodiments, Presentation artifacts communicate to the middle tier objects to store and retrieve data from the database layer. Typical implementation guidelines would specify the technology platform features that would be used including communication from presentation to back end using XML documents. The guideline would specify that the distributed transaction capabilities of COM+ should be used.
Given these requirements for implementation with Microsoft technology platform, the mapping is given in the following Table 1.
TABLE 1
Implementation in the
Mapped Design-
sample technology
Requirements
specification provides
architecture (for
specification Business
corresponding Technical
example, Microsoft-
architecture elements
architecture elements
based technology)
Business functions
Components, Business
Tables in a RDBMS-
Objects
like MS SQL server
Business activities
System entry points
Menu items imple-
mented using ASP,
HTM
User interfaces or
Screens
HTML pages, Active
forms
server pages
Tasks or actions
Services
COM + DLLs
performed on the user
implementing the
interface
service behavior using
Visual basic
Business rules
Process sections,
Stored procedure for
Methods
business logic, VB
code for business logic
Events
Links, Integration
Links are implemented
services, Interface
as Hyperlinks in HTM
business objects
for UI lookup. Inter-
face business objects
are implemented as
stored procedures,
views, for data lookup,
Integration services are
implemented as
COM + DLLs for
integration with
external systems.
For different technology platforms and recommendations, the mapping can be suitably specified to ensure implementation does not violate the architecture guidelines.
This provides the following advantages: a clear technology-implementation mapping that preserves adherence to architecture guidelines. Future re-implementation in other technology platforms can be driven from the same set of specifications and specific mapping. The clear separation of concern between the architect, engineer and implementer leads to better productivity and discipline. The architect's concerns now focus on business needs without being constrained by the implementation methodology or technology. The engineer's concerns are now to design the system to address the business needs without being constrained by technology. The implementer's concerns are now for developing the system using a particular technology to address the business needs based on the design.
FIG. 4 is an overview diagram of a hardware and operating environment in conjunction with which various embodiments of the invention may be practiced. The description of FIG. 4 is intended to provide a brief, general description of suitable computer hardware and a suitable computing environment in conjunction with which some embodiments of the invention may be implemented. In some embodiments, the invention is described in the general context of computer-executable instructions, such as program modules, being executed by a computer, such as a personal computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types.
Moreover, those skilled in the art will appreciate that the invention may be practiced with other computer system configurations, including hand-held devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCS, minicomputers, mainframe computers, and the like. The invention may also be practiced in distributed computer environments where tasks are performed by I/O remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.
In the embodiment shown in FIG. 4 , a hardware and operating environment is provided that is applicable to any of the servers and/or remote clients shown in the other Figures.
As shown in FIG. 4 , one embodiment of the hardware and operating environment includes a general purpose computing device in the form of a computer 20 (e.g., a personal computer, workstation, or server), including one or more processing units 21 , a system memory 22 , and a system bus 23 that operatively couples various system components including the system memory 22 to the processing unit 21 . There may be only one or there may be more than one processing unit 21 , such that the processor of computer 20 comprises a single central-processing unit (CPU), or a plurality of processing units, commonly referred to as a multiprocessor or parallel-processor environment. In various embodiments, computer 20 is a conventional computer, a distributed computer, or any other type of computer.
The system bus 23 can be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory can also be referred to as simply the memory, and, in some embodiments, includes read-only memory (ROM) 24 and random-access memory (RAM) 25 . A basic input/output system (BIOS) program 26 , containing the basic routines that help to transfer information between elements within the computer 20 , such as during start-up, may be stored in ROM 24 . The computer 20 further includes a hard disk drive 27 for reading from and writing to a hard disk, not shown, a magnetic disk drive 28 for reading from or writing to a removable magnetic disk 29 , and an optical disk drive 30 for reading from or writing to a removable optical disk 31 such as a CD ROM or other optical media.
The hard disk drive 27 , magnetic disk drive 28 , and optical disk drive 30 couple with a hard disk drive interface 32 , a magnetic disk drive interface 33 , and an optical disk drive interface 34 , respectively. The drives and their associated computer-readable media provide non volatile storage of computer-readable instructions, data structures, program modules and other data for the computer 20 . It should be appreciated by those skilled in the art that any type of computer-readable media which can store data that is accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, random access memories (RAMs), read only memories (ROMs), redundant arrays of independent disks (e.g., RAID storage devices) can be used in the exemplary operating environment.
A plurality of program modules can be stored on the hard disk, magnetic disk 29 , optical disk 31 , ROM 24 , or RAM 25 , including an operating system 35 , one or more application programs 36 , other program modules 37 , and program data 38 . For example, a software services delivery platform may be implemented as one or more program modules. Also for example, a web-enabled provider interface such as web-enabled provider interface 102 ( FIG. 1 ) may be implemented as one or more program modules.
A user may enter commands and information into computer 20 through input devices such as a keyboard 40 and pointing device 42 . Other input devices (not shown) can include a microphone, joystick, game pad, satellite dish, scanner, or the like. These other input devices are often connected to the processing unit 21 through a serial port interface 46 that is coupled to the system bus 23 , but can be connected by other interfaces, such as a parallel port, game port, or a universal serial bus (USB). A monitor 47 or other type of display device can also be connected to the system bus 23 via an interface, such as a video adapter 48 . The monitor 40 can display a graphical user interface for the user. In addition to the monitor 40 , computers typically include other peripheral output devices (not shown), such as speakers and printers.
The computer 20 may operate in a networked environment using logical connections to one or more remote computers or servers, such as remote computer 49 . These logical connections are achieved by a communication device coupled to or a part of the computer 20 ; the invention is not limited to a particular type of communications device. The remote computer 49 can be another computer, a server, a router, a network PC, a client, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 20 , although only a memory storage device 50 has been illustrated. The logical connections depicted in FIG. 4 include a local area network (LAN) 51 and/or a wide area network (WAN) 52 . Such networking environments are commonplace in office networks, enterprise-wide computer networks, intranets and the internet, which are all types of networks.
When used in a LAN-networking environment, the computer 20 is connected to the LAN 51 through a network interface or adapter 53 , which is one type of communications device. In some embodiments, when used in a WAN-networking environment, the computer 20 typically includes a modem 54 (another type of communications device) or any other type of communications device, e.g., a wireless transceiver, for establishing communications over the wide-area network 52 , such as the internet. The modem 54 , which may be internal or external, is connected to the system bus 23 via the serial port interface 46 . In a networked environment, program modules depicted relative to the computer 20 can be stored in the remote memory storage device 50 of remote computer, or server 49 . It is appreciated that the network connections shown are exemplary and other means of, and communications devices for, establishing a communications link between the computers may be used including hybrid fiber-coax connections, T1-T3 lines, DSL's, OC-3 and/or OC-12, TCP/IP, microwave, wireless application protocol, and any other electronic media through any suitable switches, routers, outlets and power lines, as the same are known and understood by one of ordinary skill in the art.
In the foregoing detailed description of embodiments of the invention, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the detailed description of embodiments of the invention, with each claim standing on its own as a separate embodiment. It is understood that the above description is intended to be illustrative, and not restrictive. It is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined in the appended claims. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein,” respectively. Moreover, the terms “first,” “second,” and “third,” etc., are used merely as labels, and are not intended to impose numerical requirements on their objects.
|
A method and apparatus to afford a technical application for gathering, storing, tracking, and using requirements, engineering software for those requirements, and releasing finished enterprise software. A method is described that gathers requirements into a constrained data structure designed to facilitate the engineering of pre-specified definitions of the work to be done. A data structure and schema are described that organizes the gathering of requirements, the engineering of software that meet those requirements, and the orderly release of the software components. A computer readable medium is described, the medium having computer executable instruction to cause a system perform the method.
| 8
|
BACKROUND OF THE INVENTION
[0001] This invention relates in general to protocols for transmitting digital data and, in particular, to protocols for use in real-time, high data rate devices such as color printers.
[0002] The real time, high data rates required by fast color printers present major interconnect packaging and data integrity issues. For example, in a state of the art production color printer, the required data transfer rate and cable distance between the Digital Front End (DFE) and the Image Output Terminal (IOT) is 150 MB/s and 75 feet for each color separation. For color printing, four-color separations (CMYK) would be needed and require a total of 600 MB/s data transfer. No known serial or parallel interface (with existing protocols) can meet the required cable length and bandwidth requirements for real time data where higher level error detection and retransmission of data is not practical.
[0003] For example, the Xerox DC-60 color printer DFE to IOT interface is a parallel interface implemented on copper wire. Forty lines (times four, one set for each color separation) are used to transmit the protocol which includes differential signals such as a clock, page request, line request, line valid and lines for data. The maximum data transfer achievable with this system is 70 MB/s. The fiber channel and SCSI protocols are high-level protocols with significant overhead (several layers to differentiate senders, error checking and retransmission) and non-real-time characteristics which make them unsuitable for high speed, real time applications, such as for color printers. Because of such overhead, such protocols transmit only 60-70% of the available bandwidth as data. A high speed serial interface with minimal overhead for uncompressed data is required.
SUMMARY OF THE INVENTION
[0004] A high speed, serial interface according to the invention employs a simplified protocol which minimizes overhead enabling uncompressed image data to be sent serially over a long distance in real-time devices, such as a color printer. Because the error rate experienced in high speed serial and fiber optic links is very small and finite, the high speed, serial interface and protocol removes the requirement to retransmit real time data. With error rates expected to be in the range of 10 −12 , an occasional incorrect pixel or tag is not detectable by the user. This link can be standardized for a wide range of high-speed target device interfaces.
[0005] A high speed serial interface, according to the invention, includes an initiator device for generating data and messages, wherein the initiator device includes a transceiver for sending and receiving data and messages using a serial protocol; a target device for receiving data and messages, wherein the target device includes a transceiver for sending and receiving data and messages using the serial protocol; and a transmission media for coupling the initiator device and the target device; wherein the serial protocol includes a plurality of time frames comprising an idle message time frame for indicating a device is ready for communication, wherein each of the initiator device and the target device transmits an idle frame when it is ready for communication; a control word frame for sending a data request from the target device; a control word frame for indicating a transfer mode from the initiator device; and a data frame, wherein in response to a data request from the target device, the initiator device transmits a control word frame followed by the requested data.
[0006] A protocol structure for high-speed, serial initiator device-target device communications includes a plurality of time frames comprising an idle message time frame for indicating a device is ready for communication, wherein each of the initiator device and the target device transmits an idle frame when it is ready for communication; a control word frame for sending a data request from the target device; a control word frame for indicating a transfer mode from the initiator device; and a data frame, wherein in response to a data request from the target device, the initiator device transmits a control word frame followed by the requested data.
[0007] A protocol structure for high-speed, serial DFE-printer communications, includes a plurality of time frames comprising an idle message time frame for indicating a device is ready for communication, wherein each of the DFE and the printer transmits an idle frame when it is ready for communication; a printer control word frame for sending a page request and a line request from the printer; a DFE control word frame for indicating a transfer mode from the DFE; and a data frame, wherein in response to a page request from the printer, the DFE transmits a control word frame followed by the requested data.
[0008] The high speed serial interface with protocol can be used for communications between any initiator and target devices, and is easily implemented for high speed color printers. For example, the high-speed serial link was implemented between the Xerox Multi-mode Decompression Module (XDM3-C) residing in the Xerox Controller and the Interface Card (XIC) in the print engine (IOT). The high speed serial interface implementing the protocol sends real-time image data and tag to the print engine at 1.5 Gbps. Four high speed serial interfaces are used to drive four color separation data to the IOT. This is done without requiring high-level protocol software support. The high speed serial interface is implemented using fiber optics as a transmission media for long distance, although copper may be used for shorter distances and provides a cost reduced option. With very small but finite error rates (estimated to be 10-12), an occasional incorrect pixel or tag may be transmitted with no degradation in observed image quality or user satisfaction.
[0009] The XDM3-C decompresses compressed data and sends the decompressed data (raw video) to the XIC in the print engine in real-time. The high speed serial interface includes a transmit and receive pair and operates in full duplex mode. The protocol in this embodiment is point-to-point protocol between the XDM3-C and the XIC, however additional bits in the control words could be added to identify sender and destination. No embedded processor on both sides is needed to manage protocols and data flow. Data transfer on the serial link is 8b/10b encoded and at 1.5 Gbps or 150 MB/s for image and tag. Total bandwidth for four links is 600 MB/s. This interface can be run faster by increasing the sender and receiver's clock speed and media transmission rate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a block diagram of a high speed serial interface between a DFE and an IOT;
[0011] [0011]FIG. 2 is a block diagram of a XIC module;
[0012] [0012]FIG. 3 is timing diagram of a single event control word;
[0013] [0013]FIG. 4 is a timing diagram of a control word followed by data words;
[0014] [0014]FIG. 5 is a timing diagram of scanline request;
[0015] [0015]FIG. 6 is a timing diagram of scanline request after first mode select;
[0016] [0016]FIG. 7 is a timing diagram of the XIC FIFO prefill for the first page;
[0017] [0017]FIG. 8 is a timing diagram of the end of page timing;
[0018] [0018]FIG. 9 is a block diagram of a XDM3-C module;
[0019] [0019]FIG. 10 is a timing diagram of a XIC line request and XCII transmission;
[0020] [0020]FIG. 11 is a timing diagram of a XCII to XIC scanline packet in normal model
[0021] [0021]FIG. 12 is a timing diagram of XCII to XIC control and data transfer in diagnostic mode; and
[0022] [0022]FIG. 13 is a timing diagram of XIC to XCII control and data transfer in diagnostic mode.
DETAILED DESCRIPTION
[0023] The high speed serial interface and protocol of the invention may be used to facilitate communication between any initiator device and any target device. For convenience, the high speed serial interface and protocol will be described in particularity with regard to an implementation embodied in the Xerox Constellation DFE-IOT.
[0024] The following abbreviations are used throughout and are listed here for convenience:
CMYK Cyan, Magenta, Yellow, Black Color Model CPLD Complex Programmable Logic Device CRM Contone Rendering Module IOT Image Output Terminal JIDI Jadis Image Data Interface XCM3 Xerox XM2 Compression Module XDM3 Xerox XM2 Decompression Module XCII XM2 Combiner IOT Interface ASIC XIC Constellation Interface Card XM2 Xerox Multi-Mode Compression Technology
[0025] Referring to FIG. 1, DFE 20 is implemented with a high performance Sun platform and the addition of an XCM3-A compression module (not shown) and two XDM3-C decompression modules 22 , 24 . The XDM3-C decompression modules 22 , 24 decompress the Xerox XM2.3 format color images and provide CMYK color data on four separate channels 42 , 44 , 46 , 48 . Two XDM3-C modules are used for the four color channels. Module 22 delivers the cyan 42 and magenta 44 channels. Module 24 delivers the yellow 46 and black 48 channels. The number of modules is a matter of convenience. All four channels could be included on a single module or each channel could have its own module.
[0026] The Constellation Interface Card (XIC) 32 , 34 , 36 , 38 resides in the IOT 30 and receives color image data from the DFE 20 . The Image data is sent from the XDM3-C modules to four XIC cards over a high speed serial link 40 . Each card buffers a minimum of two scanlines of image data, which is passed to four Contone Rendering Modules (not shown) over a JIDI bus. No microprocessor is required to monitor the image data flow. Each card supports peak image and tag data rates of 1.2 Gbits per second. The CRM cards provide the rendering of the image by converting the 8 bit contone data to the highly addressable binary data required by a laser printing engine. The highly addressable binary data is sent to the ROS Interface Modules (RIM) which in turn drive the Raster Output Scanner (ROS) for each color plane.
[0027] Referring to FIG. 2, a block diagram of XIC card 32 is shown. Image and tag data 42 from XDM3-C interface 22 is received at fiber optic transceiver 310 . Fiber optic transceiver 310 generates a serial electrical signal indicative of the image data which is sent to transceiver 312 / 316 (which consists of receiver 312 and transmitter 316 ), which converts the serial signal into 16 bit parallel raw video and latched by latches 326 and 324 . This data is buffered in a 48 bit wide high speed synchronous FIFO 328 and passed through to the JIDI bus 360 via drivers 350 and 352 .
[0028] The XIC implementation incorporates three different clocks. The FIFO input logic is clocked by the 75 MHz TLK1501 receiver clock 314 RX_CLK. This clock is recovered from the serial data stream sent from the XDM3-C. The TLK1501 Transmitter and control logic are clocked by the 75 MHz transmitter clock 318 GTX_CLK. The FIFO output logic and JIDI interface are clocked by the 25 MHz JIDI bus clock (not shown).
[0029] In this implementation the serial transceiver 312 / 316 is implemented with the Texas Instruments TLK1501 1.5 to 2.5 Gbps transceiver. This device handles the complexity of encoding, multiplexing, clock extraction, demultiplexing, and decoding. Other suitable transceivers may also be used.
[0030] The fiber optic interface is implemented with a compact optical transceiver 310 containing a semiconductor laser and PIN photodiode. A suitable package for the optical transceiver 310 is the Small Form Factor package. This package implements ten pins and utilizes the duplex MT-RJ connector. The transceiver 310 should support rates up to 1.5 Gbits per second on the link with cable lengths up to 200 feet. Molex currently offers a 1.5 Gbit per second optical transceiver in a 1×9 pin configuration with dual SC connectors, but other suitable transceivers may also be used.
[0031] The fiber optic cabling 40 connecting the XDM3-C and XIC implements a multi-mode fiber in each direction. One cable is used for each of the four XIC cards in the system. The fiber optic interface is designed to support a cable length up to 100 feet for this embodiment.
[0032] Alternatively a copper interface may be used. The copper interface option utilizes a very high bandwidth cable that is driven by the differential outputs of the TLK1501 transmitter. AC coupling is used to isolate the logic ground of the DFE from the logic ground of the IOT. The copper interface is designed to support a total cable length of 15 meters for this embodiment.
[0033] The FIFO buffer 328 may implemented with three 8K×16 bit high speed synchronous FIFO devices. This buffer has a total capacity of 48K bytes which represents 3.79 scanlines. Since data transfer in this embodiment from the XDM3-C is initiated when the FIFO is less than half full, the FIFO will not contain more than 2.895 scanlines under normal conditions. One device that may be used is the IDT72V263 from Integrated Device Technology, Incorporated. The IDT72V263 is a 3.3 volt, high density SuperSync II™ narrow bus FIFO.
[0034] The TLK1501 transmitter clock GTX_CLK is used for the FIFO write clock. The three FIFO devices are written individually as each 16 bit word is received from the XDM3-C. The JIDI bus DCLK is used for the FIFO read clock. The FIFO is read 48 bits at a time for data transfer to the JIDI bus.
[0035] The high speed serial interface operates in both normal mode and diagnostic mode (described below). Diagnostic mode allows the XIC 32 to return data in the XIC FIFO 322 (a separate FIFO for storing diagnostic data) to the XDM3-C. The diagnostic path includes a synchronizing FIFO 322 located between the XIC FIFO output and the TLK1501 transmitter 316 . This FIFO allows data clocked by the JIDI bus 25 MHz clock to be passed through to the TLK1501 transmitter input which is clocked at 75 MHz. Diagnostic mode is controlled by state machines implementing the high speed serial interface protocol in the CPLD controller 330 , 320 . The first state machine 330 reads the XIC FIFO 328 and writes the data into the diagnostic FIFO 322 . The second state machine 320 reads the diagnostic FIFO if data is available and then sends this data to the TLK1501 transmitter 316 . Both state machines transfer data on demand until the XIC FIFO is empty.
[0036] The JIDI Interface 360 includes image and tag data, clock, control, and D.C. power. The image and tag data are written to the JIDI bus under control of a state machine implemented in a CPLD 330 . The state machine responds to DFE_PageReq′ and LineReq′. Data is written to the JIDI bus under control of the JIDI bus clock DClk. The signal ILine_Valid′ is driven to provide the necessary synchronization for the device receiving the image and tag data. A counter 340 is implemented to terminate the data transfer for each scanline after the transfer of 8640 pixels. The data transfer for each scanline is accomplished with 2160 reads of the XIC FIFO 328 .
[0037] The data drivers 350 , 352 are implemented with three 16 bit wide TTL compatible open collector drivers. The JIDI bus signal Error′ is asserted if an error condition is detected. The XIC uses the JIDI bus signal IReset′ to reset the card at power up. IReset′ is also used as the error condition reset. The XIC 32 is designed for a fixed scanline length of 8640 pixels. The scanline length is specified in the CPLD 330 that controls the JIDI interface and may be changed as necessary.
[0038] Referring to FIG. 9, a block diagram of the XDM3-C module 22 is shown. XDM3-C 22 includes XCII 210 , which accepts inputs from three GZIP decompression channels, 222 , a PM37 JPEG decompressor 224 , and run-length-coded data from the XDPC3 chip 220 . The three GZIP 222 decompression channels contain the XM2.3 Upper Plane, Rendering Hints Plane, and the Control Plane. The JPEG decompression 224 channel contains the lower data plane. The Run-Length-Coded data (RLC) 220 contains both video data and the corresponding rendering hints. The XCII 210 combines data from Lower Plane, Upper Plane or expanded RLC data based on the Control Plane data. The XCII 210 then outputs the combined video data, accompanied by the corresponding rendering hints, to the sync dual port SRAM 226 . Video input data (upper, lower & RLC) to the XCII 210 is in either the 8×8-pixel block format or raster format. The block-to-raster conversion is accomplished by using external dual port synchronous SRAM. These SRAM's are under the control of the XCII. The Rendering Hints data is also merged by the XCII and sent to the SRAM pixel-synchronized with video data. The output section of the XCII 210 receives video and render hint data from the block to raster dual port SRAM 226 . This data is first magnified, shifted and clipped before it is stored in internal scanline FIFO (not shown). The FIFO output data 240 is then delivered to the high speed serial interface at serial transceiver 212 which converts the parallel data input into a serial signal for input to optical transceiver 214 which generates the serial optical signal for transmission over the fiber optic link to the XIC.
[0039] The interface between the XDM3-C (XCII) and the XIC is a high speed serial link implemented with the Texas Instruments TLK1501 1.5 to 2.5 Gbps Transceiver. The TLK1501 supports an optical interface through the addition of an optical transceiver at each end of the interface (as described with reference to FIG. 2 for the XIC). The high speed serial interface is configured for full duplex operation. The XDM3-C sends video, tag, and control information to the XIC. The XIC sends control and diagnostic information to the XDM3-C. The high speed serial interface employs a transmitter, receiver, and optical transceiver at each end of the link. The transmitter and receiver are 16 bit devices and run at a clock rate of 75 MHz. This provides a peak data transfer rate of 1.2 Gbits per second (150 Mbytes per second). The interface implements a protocol that supports the transmission of image data and control words.
[0040] The TLK1501 is used at both ends of the interface and provides a full duplex serial link between the XDM3-C and the XIC. The TLK1501 will transmit and receive image data at a peak rate of 1.2 Gbits per second. The transmitter encodes the data with the addition of 4 additional bits for a baud rate of 1.5 GBaud on the link. The optical interface is implemented with the addition of an optical transceiver at both ends of the link. The optical transceiver includes a semiconductor laser and PIN photodiode.
[0041] The high-speed interface provides a full duplex high-speed serial link between the XCII and the XIC. A protocol is defined for the interface of control and data signals between the XCII and the XIC. The data transferred between XCII and XIC basically consist of control words, data words and idle frames implemented according to the protocol. Each control and data word is 16 bits wide. Based on the different operational mode, the control and data words are delineated differently. An idle frame is sent while the serial link is operational if neither a valid control word or data is requested. While the serial link is up, if neither valid control word or data word is requested through the serial link, an idle frame is sent instead. Control words may be sent as a single event or immediately preceding image data.
[0042] A control word sent from XIC to XCII includes: three fixed pattern control bits of ‘101’ for verification, two XIC operation mode bits, page request and line request bits for separation ‘0’ and ‘1’, XIC FIFO half-full and empty status bits for separation ‘0’ and ‘1’, XIC reset complete bit, XIC error bit and JIDI reset status bit. The data word from XCII to XIC carries the image data in normal operation or the diagnostic data in diagnostic mode.
[0043] There may be six operation modes: XCII/XIC normal mode, XCII/XIC diagnostic mode, High speed transceiver internal loop-back mode, XDM3 channel to channel look back mode, local PRBS test mode and channel 1 and channel 2 PRBS test mode. For convenience, only normal mode and diagnostic mode are described below.
[0044] When the system is configured to run in high speed interface mode and operates in either XCII and XIC normal mode or diagnostic mode, the system has to perform a ‘two steps reset sequence’ from XCII to XIC. In other high-speed operation mode and all other operation modes, this reset sequence is not required. A ‘two steps reset sequence’ from XCII to XIC is done by performing two writes to the XCII to XIC control register. The first write with Bit [ 8 : 6 ]=101 is sent to XIC, to reset the related logic. The second write with Bit [ 8 : 6 ]=010 terminate this reset cycle. During these two writes, the Bit [ 5 : 4 ] for operation mode bits, and the Bit [ 3 : 0 ] for LED (if the optional LED is present in the system) must be set correspondingly and transferred to XIC. The operational mode bits should be set to the same values in both of these two reset sequences. Bit [ 5 : 4 ]=00 for normal operation and 11 for diagnostic function.
[0045] To ensure proper reset to the XIC, the reset cycle to XIC must be at least 1 microsecond long. In other words, the interval between these two write cycles in this reset sequence must meet this restriction by checking and ensure the Bit 9 =0 in the XCII to XIC control register, before performing the next write to this control register.
[0046] At power up, it will take a moment for the high-speed transceiver to initialize and then enters into idle state. When running the XCII and XIC in normal or diagnostic mode both XCII and XIC wait to receive the idle frame each other to ensure the link is up before any control or data word is sent.
[0047] When the fiber optic link is up the system performs the first write of the ‘two steps reset sequence’ with XIC reset Bit [ 8 : 6 ]=101 to the XCII to XIC control register. One microsecond later the XIC should receive a second reset control word with Bit [ 8 : 6 ]=010 from the XCII. When XIC receives the second reset control word and completes the reset function it will send exactly one control word cycle with the Reset Complete bit=1 to XCII. This is followed by the transmission of a series of control words if it is in normal mode or by an idle frame in diagnostic mode. The system is required to perform this two steps XIC reset sequence any time when the mode is reconfigured. This reset sequence is performed right after the system has completed programming the global configuration register. If the reset sequence is not complete properly or reset at incorrect time, it is declared as reset error and the XCII issues an interrupt.
[0048] In normal mode, image and tag data are transferred from XCII to XIC. Normal mode further supports either single or dual-separations mode. In single separation mode all data comes from the separation ‘0’ FIFO, which is consist of toggling between even and odd scanline FIFOs.
[0049] In dual-separation mode, the data will come from both of separations, even and odd FIFOs. The current scanline delivered will depend on which scanline request is received from the high-speed interface. The data output can be either from a single separation or scanline interleaved between separations depending on the separation's scanline requests. Only one scanline can be outputted at a time so both separation ‘0’ and ‘1’ scanline requests should not be asserted at same time. In this mode, when the two-step reset sequence is completed by the XCII and the XIC finishes the reset function, the XIC will return a control word with reset complete bit=1 for exactly one cycle. From that point the XIC continuously transfers the control word with page requests and line requests etc. to XCII, and XCII responds by sending scan line data to XIC. At any time when the mode is reconfigured between normal and diagnostic, the system is required to perform the two-steps XIC reset sequence.
[0050] In this mode, basically the word transferred from XCII to XIC right after the idle frame is considered as control word, otherwise it is the data word. There are two types of control words. A single control word is delineated as a single data frame inserted between two idle frames, refer to FIG. 3, it can be sent any time, between pages, after power up, with no image data followed. The first word transfer in the stream of scan-line data is also considered as control word, refer to FIG. 4, it may carry the LED display message, but is not intended to be used as reset control word.
[0051] A pre-fill of two scan-lines to the XIC FIFO is required before each page printing, refer to FIGS. 5, 6 and 7 . For first page pre-fill process, XCII will monitor the line request only and ignore the page request from the XIC, and start to deliver the data to XIC if the XCII scan line FIFO has at least one scan line data available. A pre-fill process also takes place in interpage gap for next page printing, refer to FIG. 8. An entire scan line contains a control word followed by 6480 continuous sixteen bit data word transfer and ends with a idle frame, refer to FIG. 11. The idle frame at the end of scan line indicates to the XIC that it is the end of current scan line.
[0052] XIC will negate the line request signal, once it receives the first word of image data, as defined, the first word of each scan line is the control word. See FIG. 10. At the end of each scan line, if XIC FIFO has enough space, the next line request is reasserted and send to XCII. This operation continues until the last line request is received by XCII and XCII has delivered the last scan line data to XIC for the entire page.
[0053] At that point, XCII will ignore further line request even it is active and wait until XCII detects that previous page request dropped and XIC FIFO emptied, then the line request for next page pre-fill is recognized. In dual-separations mode, each separation pre-fill process is similar to that in one-separation mode. At end of page, both separation ‘0’ and ‘1’ FIFOs must be checked for empty, before the pre-fill for next page can be initiated. The programming sequence to run this operation is as follows:
[0054] 1) Program the Global configuration register as follows:
[0055] Bit [ 12 ]=0;
[0056] Bit [ 11 ]=set as desired; Disable Rendering Hints Bit [ 10 : 8 ]=000;
[0057] Bit [ 7 : 6 ]=00;
[0058] Bit [ 5 ]=0;
[0059] Bit [ 4 ]=0;
[0060] Bit [ 3 ]=0;
[0061] Bit [ 2 ]=0;
[0062] Bit [ 1 : 0 ]=10 for dual separations: 11 for single separation.
[0063] 2) Programming image size related registers, such as the pixel per scan-line registers, scan-line per page registers and enable related interrupt.
[0064] 3) Perform two-steps reset sequence to XIC.
[0065] 4) Set Separation GO bit
[0066] In Diagnostic Mode the XCII receives the same data that it wrote to the XIC. This read-back data is written to the loop-back FIFO. The XCII then DMAs the loop-back data over the local bus back to the system. When a mode change is required to set XCII and XIC in diagnostic mode, the two steps reset sequence is performed. See FIG. 12. After XCII has sent the second reset control word to XIC, XIC will send exact one control word cycle with reset Complete bit=1 to XCII when XIC reset function is complete. At that point, XIC must put transceiver in idle state for at least one cycle before starting to send the returned diagnostic data frame back to XCII if data is available. After one reset complete control word is sent, no more control word are sent from XIC to XCII. All other word transfer is considered as returned diagnostic data words and single or multiple idle frames can be inserted in between. See FIG. 13.
[0067] Due to limited size of loop-back FIFO in the XCII for buffering the returned data, XCII can transfer a package of 13 words at a time. The first word in the burst is considered to be the Control word and the rest are Data words to XIC, refer to FIG. 12. The XCII will not transfer the next burst of data until the current burst is received back from XIC. In this mode, the first word following the idle frame from the XCII to XIC is the control word, reference FIG. 12. It is also the first word of the packet. The control word in this packet is not intended for reset or mode change purpose, it is for updating the LED display etc. When mode is reconfigured between normal and diagnostic, it is required to perform two-steps reset sequence to XIC.
[0068] The programming sequence to run this operation is as follows:
[0069] 1) Program the Global Configuration Register as follows:
[0070] Bit [ 12 ]=0;
[0071] Bit [ 11 ]=0;
[0072] Bit [ 10 : 8 ]=set as desired;
[0073] Bit [ 7 : 6 ]=10;
[0074] Bit [ 5 ]=1 for separation ‘1’:
[0075] 0 for separation ‘0’;
[0076] Bit [ 4 ]=1 for DMA: 0 for I/O;
[0077] Bit [ 3 ]=1;
[0078] Bit [ 2 ]=0;
[0079] Bit [ 1 : 0 ]=11.
[0080] [0080] 2 ) Programming image size related registers, such as the pixels per scan-line register, scanline per page registers, and enable related interrupt.
[0081] 3) Perform two-steps reset sequence to XIC.
[0082] 4) Set the separation GO bit.
[0083] The bit assignments for the XDM3-C (XCII) to XIC control words are shown in the table below.
Bit Assignment Signal 15 1 14 0 13 1 12 0 11 Spare 10 Spare 09 Spare 08 XIC Reset 07 XIC Reset′ 06 XIC Reset 05 Mode 01 04 Mode 00 03 Test LED 3 02 Test LED 2 01 Test LED 1 00 Test LED 0
[0084] BITS 15 : 12 : are defined as the fixed pattern 1 0 1 0. The XIC will use these bits to verify receipt of a valid Control Word.
[0085] XIC RESET: XIC Reset and XIC Reset′ are used by the XDM3-C to reset the XIC and clear the FIFO buffer. Three bits are used to reduce the probability of a false reset. XIC Reset and XIC Reset′ are asserted to their respective states for a minimum of one microsecond.
[0086] Reset of the XIC is a two step process. In the first step XIC Reset is set to a logic 1 , and XIC Reset′ is set to a logic 0. The XIC returns a series of continuous control words to the XDM3-C with the Reset Complete bit equal to a logic 0. Idle characters are inserted to maintain synchronization. In the second step XIC Reset is set to a logic 0, and XIC Reset′ is set to a logic 1 to complete reset sequence. The XIC returns a minimum of two sequential control words to the XDM3-C with the Reset Complete bit equal to a logic 1.
[0087] XIC mode changes are enabled in conjunction with XIC Reset.
[0088] MODE
[0089] [0089] 01 : 00
[0090] The Mode bits are used to specify the mode of operation. Normal Mode is used to send image and tag data to the XIC. Diagnostic Mode is used to enable data turnaround on the XIC. In Diagnostic Mode the XIC reads data in the XIC FIFO and returns it to the XDM3-C. XIC mode changes require an XIC Reset to take place. Normal Mode is specified by setting Mode 0 to a logic 0. Diagnostic Mode is specified by setting Mode 0 to a logic 1. The mode bits are specified throughout the duration of the reset sequence.
[0091] The bit assignments for the XIC to XDM3-C (XCII) control words are shown in the table below.
Bit Assignment Signal 15 1 14 0 13 1 12 Mode 11 0 (Reserved) 10 1 (Reserved) 09 Reset Complete 08 Scanline Request 1 07 Scanline Request 0 06 Page Request 1 05 Page Request 0 04 Link Ready 03 FIFO Half Full 02 FIFO Empty 01 JIDI Error 00 JIDI Reset
[0092] BITS 15 : 13 : Control Word Bits 15 : 13 are defined as the fixed pattern 1 0 1. The XDM3-C may use these bits to verify receipt of a valid Control Word.
[0093] MODE: The Mode bit is provided for verification of XIC mode changes that are made as part of the reset sequence. The XDM3-C may verify the mode by testing this bit at the end of the reset sequence.
[0094] RESET COMPLETE: Reset Complete is used to indicate the completion of a reset sequence and mode change. The XIC returns at least two sequential control words to the XDM3-C with the Reset Complete bit equal to a logic 1 at the end of the reset sequence.
[0095] SCANLINE REQUEST: Scanline Request is sent from the XIC to the XDM3-C to request one scanline of image and tag data. This signal is derived from the FIFO Half Full Flag. Scanline Request is initially set if the FIFO buffer is less than half full. Scanline Request is reset by the XIC after it has received the first valid 16 bit word of XDM3-C image data. Scanline Request is set after the XIC has received a scanline of data from the XDM3-C if the FIFO is less than half full. End of scanline is indicated by idle in the TLK1501 receiver. The XIC provides two dedicated Scanline Request signals for compatibility with the XDM3-C design. The XIC utilizes Scanline Request 0. The XDM3-C is required to start data transfer within a specified time after detecting Scanline Request. This time is specified as 1 microsecond maximum.
[0096] PAGE REQUEST: This signal is the Page Request signal received from the JIDI bus. The XDM3-C sends image data to the XIC prior to the start of each page. This is required to meet JIDI bus timing requirements. The XIC provides two dedicated Page Request signals for compatibility with the XDM3-C design. The XIC utilizes Page Request 0.
[0097] LINK READY: Link Ready is set if the following two conditions are met: The XIC TLK2500 receiver is receiving idle frames or normal data characters. The optical transceiver signal detect output indicates sufficient signal for reliable operation of the link.
[0098] FIFO HALF FULL: This signal is the Half Full Flag provided by the XIC FIFO. FIFO Half Full is sent as a status and diagnostic signal only.
[0099] FIFO EMPTY: This signal is the Empty Flag provided by the XIC FIFO. FIFO Empty is sent as a status and diagnostic signal only.
[0100] JIDI ERROR: This signal indicates that the XIC has asserted the Error Signal on the JIDI bus. Error conditions include the following cases: FIFO Empty during data transfer to JIDI bus; FIFO Full during data transfer to JIDI bus; Error is sent as a status and diagnostic signal.
[0101] JIDI RESET: This signal is the Reset Signal received on the JIDI bus. Reset is sent as a status and diagnostic signal.
[0102] The XIC sends diagnostic data to the XDM3-C in diagnostic mode. The diagnostic data is sent by the TLK1501 transmitter. In diagnostic mode, the XIC reads data in the XIC FIFO and returns it to the XDM3-C. The diagnostic path includes a 16 bit synchronizing FIFO located between the XIC FIFO output and the TLK1501 transmitter. The synchronizing FIFO allows data clocked by the JIDI bus 25 MHz clock to be passed through to the TLK1501 transmitter input which is clocked at 75 MHz. The XIC returns XIC FIFO data to the XDM3-C when diagnostic mode is enabled.
[0103] In diagnostic mode the XIC does not send the Control Signals defined. As a result, the Scanline Request signal is not used. Since mode changes are made in conjunction with XIC Reset, the XIC FIFO will be cleared when Diagnostic Mode is enabled. The test sequence on the XDM3-C must accommodate round trip cable and interface delays. After Diagnostic Mode is enabled, the XIC will return Reset Complete. This is followed with idle frames until data is received from the XDM3-C.
[0104] After receiving Reset Complete, the XDM3-C may send diagnostic image data which will be written into the XIC FIFO. Since the Scanline Request signal is not used, the size of the data block sent by the XDM3-C must be no larger than the capacity of the XIC FIFO. The first word sent by the XDM3-C after idle is still defined as a Control Word in Diagnostic Mode.
[0105] In diagnostic mode, the XIC reads the 48 bit FIFO and returns the data to the XDM3-C with three 16 bit write cycles. The operation continues until the XIC FIFO is empty. Since the synchronizing FIFO is 16 bits wide and written at 25 MHz, the data returned to the XDM3-C will include both idle frames and data frames. The XIC is typically returned to Normal Mode after completion of the diagnostic test. The continuous Control Words resume in Normal Mode. Idle and valid data on the XDM3-C are indicated by the state of the TLK1501 receive data controls.
[0106] The protocol structure and method of the invention may be implemented in: application software such as image processing and editing software, operating systems having image processing capabilities, printer or display driver software, hardware such as ASIC chips and CPLDs in DFE's, printers, computers, or other image display or generation devices, or any other device or source for image generation.
[0107] The invention has been described with reference to a particular embodiment. Modifications and alterations will occur to others upon reading and understanding this specification taken together with the drawings. The embodiments are but examples, and various alternatives, modifications, variations or improvements may be made by those skilled in the art from this teaching which are intended to be encompassed by the following claims.
|
A high speed, serial interface employs a simplified protocol which minimizes overhead enabling uncompressed image data to be sent serially over a long distance in real-time devices, such as a color printer. Because the error rate experienced in high speed serial and fiber optic links is very small and finite, the protocol removes the requirement to retransmit real time data. The protocol for initiator device-target device communications includes an idle message frame for indicating a device is ready for communication; a control word frame for sending a data request from the target device; a control word frame for indicating a transfer mode from the initiator device; and a data frame, wherein in response to a data request from the target device, the initiator device transmits a control word frame followed by the requested data.
| 7
|
This invention relates to arrangements for balancing operating spin-stabilized spacecraft, and more particularly to arrangements for balancing such spacecraft by transferring liquid between two or more fluid containers or tanks.
The instruments carried by satellites or space vehicles tend to be directional in nature, so that the characteristics of particular portions of the environment may be examined or contacted. Such instruments include television cameras, telescopes, laser or radar altimeters and the like, and also include communication devices such as reflector-type directional antennas. The use of such instruments requires that the spacecraft be stabilized to prevent the object being examined from leaving the field of view of the instrument.
Spacecraft may be stabilized by three-axis stabilization schemes using wheels or thrusters or, when in planetary orbit, magnetic torquers to maintain a particular attitude. Another common type of stabilization is spin stabilization, in which the spacecraft spins about an axis, whereupon the spin axis tends to maintain a constant orientation in inertial parallel to the spin axis, or a despun platform may support instruments looking in other directions.
The desired spin axis of a spin-stabilized satellite is established during its design and construction. The various masses of the elements making up the spacecraft are distributed about the intended center of mass in such a fashion that under ideal conditions, spin takes place about the desired axis. Very often, however, the actual spin axis will deviate from the desired spin axis. Such deviations may occur due to thermal changes in the dimensions of various parts, which move the centers of mass of the various portions relative to the axis, or due to distributions of fuels or other fluids contained in tanks that differ from the projected distributions, or possibly due to uneven consumption of consumables such as fuel or oxidizer from various tanks placed about the space vehicle. Whatever the cause of such imbalances, they may adversely affect the pointing accuracy of instruments mounted on the space vehicle. As an extreme example, a star sensor whose field of view is directed along the desired spin axis might, in an unbalanced situation, scan a field of view in a form of an annulus about the desired star, never being able to see it.
U.S. Pat. No. 4,432,253 issued Feb. 21, 1984 to Kerlin describes compensator for dynamically balancing rotary elements by changing the mass distribution in a plurality of chambers spaced about the rotational axis. The mass is redistributed by heating the fluid in a chamber and conducting the vapor produced by heating to another chamber or chambers, where the vapor condenses, therefore transferring mass from one chamber to another chamber. This arrangement suffers from the disadvantage that, because the vapor must be condensed in a chamber, the chamber must have a temperature below the dew point of the vapor. In the context of a space vehicle, additional structure may be required to provide cooling to a chamber, and such additional structure adds weight to the spacecraft. It is generally considered to be undesirable to add weight to a spacecraft, as this reduces the amount of fuel or payload which can be carried. A further disadvantage of the Kerlin arrangement is that balance control is relatively slow, because the mass transfer rate is low.
An improved dynamic balance compensator is desired.
SUMMARY OF THE INVENTION
A method is described for balancing a spinning spacecraft which includes first and second fluid containers The method includes the steps of sensing an unbalanced condition of the spacecraft and transferring liquid from the first container to the second container in a manner which reduces the unbalance. A spacecraft adapted to carry out the method includes first and second containers for fluid and a fluid distribution arrangement coupled and to the first and second containers for enabling liquid flow between the first and second containers. A balance sensing arrangement is coupled to the spacecraft structure and is adapted for generating signals indicative of an unbalanced condition of spin. A differential pressure generating arrangement is coupled to the first and second containers and to the balance sensing arrangement, and is responsive to the signals produced by the balance sensing arrangement for generating a pressure differential between the first and second containers, which causes fluid to flow through the fluid distribution arrangement in a manner tending to reduce the unbalanced condition. In a particular embodiment of the invention, the fluid is fuel, which is redistributed through a fuel distribution manifold.
DESCRIPTION OF THE DRAWING
FIG. 1 illustrates in simplified schematic form a spacecraft in accordance with the invention which is adapted for balance by liquid transfer between containers;
FIG. 2 is a simplified schematic diagram of a spacecraft according to an embodiment of the invention arranged for automatic spin balance control in accordance with an aspect of the inventions;
FIG. 3 is a simplified schematic diagram which illustrates a spacecraft arranged for remote control of the spin balance in accordance with another embodiment of the invention.
DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic representation of a spin balance arrangement according to the invention. In FIG. 1, a spacecraft illustrated by a dotted outline 10 includes a first container 12 for fluid and a second container 14 that is connected to container 12 by a manifold, plenum or pipe 16. Containers 12 and 14 contain fluid. The tanks may be reservoirs of coolant fluid of the type described in U.S. patent application Ser. No. 337,774 filed Apr. 13, 1989 in the name of Dowdy. As described below in connection with FIG. 2, they may be fuel containers. As yet a further alternative, the containers may be containers of FREON or other fluid used exclusively for balance purposes.
A spin axis 18 passes through the spacecraft center of mass 20. Manifold 16 connects to containers 12 and 14 at locations such that only liquid can enter or leave a container. As illustrated in FIG. 1, the liquid state 22 of the fluid contained by containers 12 and 14 lies adjacent those portions of containers 12 and 14 that are most remote from axis 18. A heater 24 is thermally coupled to container 12 at a location that is relatively close to spin axis 18, and a further heater 26 is similarly connected to a thermally coupled portion of container 14 that is relatively near spin axis 18. Since the liquid portion of the fluid contained in containers 12 and 14 tends to be displaced away from axis of rotation 18 during rotation of the spacecraft, that portion 28 of the fluid adjacent to heaters 24 and 26 is in gaseous form. This gas 28 may be the vapor form of the liquid 27 or a separate pressurant gas (such as nitrogen or helium), or a combination of vapor and pressurant gas.
In operation, one of heaters 24 or 26 is energized to heat the gas 28 contained in one of the corresponding containers 12 or 14, to thereby heat the gas adjacent to the heater and increase its pressure. The increased pressure causes liquid to transfer from the container being heated to the container not being heated. Since the density of the liquid is much greater than that of the gas, mass is transferred relatively quickly between tanks 12 and 14 when a heater is energized, by comparison with transfer by vaporization of liquid in one tank and its condensation in another.
A valve 30 is connected at a point along manifold 16 and is operable in one of two modes, to either allow the flow of liquid through manifold 16 between containers 12 and 14 or, in a second mode, to shut off or prevent the flow of liquid. Valve 30 may be placed in the first mode at the same time that one of heaters 24 and 26 is energized, to allow the flow of liquid for balancing, and then may be set in its second mode to prevent the flow of liquid, whereby the energized heater may be deenergized to conserve energy.
FIG. 2 is a simplified schematic diagram of another embodiment of the invention. Elements of FIG. 2 corresponding to those of FIG. 1 are designated by the same reference numerals. In FIG. 2, manifold 16 includes a further valve 32 spaced apart from valve 30 by a tee junction 34. Tee junction 34 allows communication between manifold 16 and a thruster 38 by way of a thruster control valve 36. Thruster 38 may be a monopropellant thruster utilizing a monopropellant liquid fuel which is stored in containers 12 and 14. Manifold 16 is used both for transfer of liquid fuel between containers 12 and 14 for purposes of balance, and is also used for supplying fuel to thruster 38.
A gyroscope illustrated as a block 40 is mounted to the body of spacecraft 10 and generates signals on a data path 42 for application to a control logic arrangement illustrated as a block 44. The signals produced by gyroscope 40 include information representing the direction and amount of deviation of actual spin axis 18 from the desired spin axis established by the setting of the gyroscope. Control logic circuit 44 performs standard operations upon the gyroscope signals and provides data to a power switch illustrated as block 46 for routing electrical power from a source 48, by way of one of conductors 50 or 52, to heaters 24 or 26, respectively, for heating that one of containers 12 and 14, respectively, which is to transfer fluid to the other container. If thruster 38 is not to be energized, valve 36 is closed and valves 30 and 32 are open by control logic 44, and the power control switch 46 is set to apply power to the appropriate heater, whereupon liquid is transferred between the containers 12 and 14 in a direction tending to reduce the spin imbalance.
The arrangement of FIG. 2 is particularly advantageous, because spacecraft already include plural fuel containers, thrusters, pipes, manifolds and valves, electrical power sources and fuel tank heaters, so little or no additional equipment is required except the control interconnections and control logic. Thus, the additional weight required for automatic spin balance control tends to be small in the arrangement of FIG. 2.
FIG. 3 is a simplified block diagram of a spacecraft adapted for remote control of a spin balance from a tracking station such as a ground station. Elements of FIG. 3 corresponding to those of FIG. 2 are designated by the same reference numerals. In FIG. 3, spacecraft 10 is viewed from a ground station designated generally as 100. An antenna 102 associated with spacecraft 10 is connected to a transmitter 104 and a receiver 106. Gyroscope 40 is connected by way of a signal encoder 108 to transmitter 104 for encoding the gyroscope signals in a manner suitable for modulation and transmission over a line-of-sight, illustrated by a dashed line 110, to a receiving antenna 112 associated with ground station 100. Ground station 100 receives transmitted signals including the modulated, encoded information from gyroscope 40, and couples it to a receiver illustrated as 114, which demodulates the signal and applies the encoded gyroscope information to a decoder 116. Decoder 116 decodes the coded gyroscope information and applies the information to a logic circuit 118, which generates signals representative of the amount of offset between the gyroscope axis and the spin axis of the spacecraft. This error information is applied from logic circuit 118 to a block illustrated as 120, which represents the implementation of a correction instruction either by means of further logic circuits, or by manual intervention. A correction instruction includes a decision as to whether sufficient electrical power is available to operate the heaters, which heater should be energized and how much, and the like. In the simple example illustrated in FIG. 3 only two fluid containers, 12 and 14, are illustrated, but in an actual situation four or more containers may be involved, and the liquid distribution might have to be changed among containers of the pairs.
The correction instructions are applied from block 120 of FIG. 3 to an encoder 122 which encodes the information in a manner suitable for modulation by a transmitter 124 and for transmission by antenna 112 back over line-of-sight path 110 to spacecraft 10. At the spacecraft, antenna 102 receives the signal and applies it to receiver 106. Receiver 106 demodulates the information and applies the encoded correction instructions to a decoder 126. Decoder 126 decodes the information, to produce signals indicative of which heater is (or heaters are) to be energized, and applies that information to power switch 46. Power switch 46 responds as described in conjunction with FIG. 2, by routing electrical power from source 48 by way of either path 50 or 52 to heaters 24 or 26, respectively, for heating that container from which liquid is to be transferred. At about the same time, decoder 126 also sends instructions to valve 30 for opening the valve to allow liquid to be transferred.
When sufficient liquid has been transferred, gyroscope 40 will indicate a reduced spin axis error or no error, and ground station 100 may decode this information and decide that sufficient correction has been accomplished At that time, block 120 of FIG. 3 produces instructions to cease the correction, which instructions are encoded in encoder 122 and modulated in transmitter 124 for transmission to spacecraft 10. In spacecraft 10, receiver 106 demodulates the modulated signals, and decoder 126 turns off power switch 46 and closes valve 30 to complete the correction operation.
While the arrangement of FIG. 3 assumes that the sensing of the unbalance occurs using information transmitted from the spacecraft, the sensing gyro aboard the spacecraft may be eliminated, and the moment-to-moment attitude of the spacecraft may be determined from Doppler shifts of the signals transmitted along line-of-sight path 110 from antenna 102 to antenna 112 if antenna 102 is displaced from the spin axis, as described generally in U.S. patent application Ser. No. 07/397,939 filed Aug. 24, 1989 in the name of Cohen. Once the attitude and errors in the spin axis are known at the ground station, instructions for correction may be transmitted to the spacecraft as described above in conjunction with FIG. 3.
Other embodiments of the invention will be apparent to those skilled in the art. For example, instead of a gyro, an appropriately located and oriented linear accelerometer could provide the necessary imbalance signal. As a further example, instead of using heaters associated with each of the containers, the containers may be exposed for radiation into space by adjustable vanes, such as vanes 140 of FIG. 2, rotatable about an axes 142, to thereby provide adjustable cooling. The movable vanes are adjusted to cool the container to which liquid is to be transferred, and not to cool the container from which liquid is to be transferred. Naturally, each container may be associated with both a heating element as described above and with cooling, if desired. Some types of spacecraft may provide cooling by means of a circulating coolant liquid and remote heat rejection panels, thereby eliminating the need to expose containers to cold space for transferring heat therefrom for cooling. Heaters such as heater 24 or 26 may be multipartite, with each part being separately controllable, so that the amount of heat transferred to each container may be varied in steps, to thereby change the temperature to which the fluid therein is raised for a given container heat loss characteristic. Alternatively, power switch 46 may be operated with a pulse-width or pulse-duration modulation to accomplish the same result. The voltage of the electrical power source may be varied as a further alternative.
|
The balance of a spin-balanced spacecraft may be dynamically adjusted by moving a liquid between or among containers spaced about the spin axis. The transfer of liquid is accomplished by controllable heaters associated with each container, for heating that container from which liquid is to be transferred to increase the pressure and drive out liquid. A spacecraft for accomplishing this method includes a balance sensing arrangements such as a gyroscope and logic for determining which container or containers are to be emptied and for controlling the heaters. Weight is minimized by accomplishing the transfer of liquid among fuel containers by way of manifolds which also supply fuel to thrusters.
| 1
|
PRIORITY UNDER 35 U.S.C. §119(e) & 37 C.F.R. §1.78
[0001] This nonprovisional application claims priority based upon the following prior U.S. provisional patent application entitled: Cane Clip, Application No.: 60/665,247, filed Mar. 25, 2005, in the names of Terry D. Beasley and Betty Beasley, which is hereby incorporated by reference for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates to a walking aid retention device, more specifically but not by way of limitation, a device attachable to a walking aid, such as a cane or crutch, for securing the walking aid to a suitable structure to maintain the walking aid in a generally vertical orientation when not in use.
BACKGROUND
[0003] Many individuals require the assistance of a walking aid device such as a cane or a crutch either temporarily or for long term due to illness or other medical condition. A fundamental problem that many of these individuals encounter occurs when the individual is at a destination with their walking aid. Often, the individual has no method of securing the walking aid to a suitable structure that will allow the walking aid to be secured in a vertical orientation in order to facilitate easier access when required.
[0004] Currently, when not in use, the individual typically has to lay the walking aid on the floor, whereby it poses a safety hazard for not only the individual but others walking in the area. Placing the walking aid on the floor has also shown to create retrieval problems for those with more serious medical conditions.
[0005] A commonly used alternative to placing the walking aid device on the floor is to temporarily lean or rest the device against a suitable structure such as a tabletop or the walls of a bathroom cubicle. As the walking aids are not secured by any method to the structure against which they are leaned, the walking aid is susceptible to being easily knocked down causing difficulty for the individual when retrieving the walking aid.
[0006] Accordingly, there is a need for a device that can be either attached to a walking aid or integrally formed therewith that allows a user to readily and releasably secure the walking aid to a suitable structure in order to maintain a vertical orientation of the walking aid when not in use.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide a device that can be attached to a walking aid, such as but not limited to a cane or crutch, that allows the user to attach the walking aid to a suitable structure when not in use to facilitate vertical storage thereof.
[0008] It is another object of the present invention to provide a device that can be releasably secured to a plurality of types of walking aids.
[0009] Yet another object of the present invention is to provide a device that can be releasably secured to a walking aid with the device being rotatable in order to facilitate attachment of the walking aid to a suitable structure and maintain the walking aid in a generally vertical position.
[0010] A further object of the present invention is to provide a device for a walking aid that uses a mechanism with variable resistance.
[0011] It is a further object of the present invention to provide device for a a walking aid that uses a mechanism that is adaptable to be secured to a plurality of objects.
[0012] Another object of the present invention is to provide a clip for a walking aid that is easy to use, inexpensive and convenient.
[0013] 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
[0014] 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:
[0015] FIG. 1 is a perspective view of an embodiment of the present invention; and
[0016] FIG. 2 is a perspective view of an embodiment of the present invention attached to a walking cane and a suitable rigid support structure.
DETAILED DESCRIPTION
[0017] Referring now to the drawings, wherein various elements depicted therein are not necessarily drawn to scale, and in particular FIG. 1 and 2 , there is illustrated a walking aid retention device 100 constructed according to the principles of the present invention
[0018] The walking aid retention device 100 comprises a base 105 that includes an upper portion 107 and a lower portion 109 . The upper portion 107 and lower portion 109 are hingedly mounted to each other by conventional mechanical methods such as a hinge pin. The upper portion 107 and lower portion 109 each have a first end 111 and a second end 113 . The base 105 is manufactured from a suitable rigid material such as but not limited to metal. A coil spring 110 is positioned intermediate the upper portion 107 and lower portion 109 proximate to the second end 113 . The coil spring 110 functions to bias the upper portion 107 and lower portion 109 in a first position against each other. The coil spring 110 is a conventional coil spring that is manufactured from a resilient metal. The coil spring 110 is attached intermediate the upper portion 107 and lower portion 109 by conventional mechanical methods such as but not limited to welding.
[0019] Although good results have been achieved with the walking aid retention device 100 as shown with a coil spring 100 , it is contemplated within the scope of the present invention that the base 105 could be manufactured to have a user controlled variable resistance biasing mechanism to mount the upper portion 107 and the lower portion 109 that would facilitate the user to control the amount of resistance required to move the upper portion 107 and lower portion 109 apart.
[0020] Still referring FIG. 1 , the base 105 includes a pair of arms 115 integrally extending from the second ends 113 wherein the pair of arms 115 are generally positioned angled outward from each other. The arms 115 are manufactured from a suitable rigid material such as but not limited to metal and are contiguous with the second ends 113 of the upper portion 107 and the lower portion 109 of the base 105 . The arms 115 are generally flat and rectangular in shape. Those skilled in the art will recognize that the arms 115 could be numerous different shapes in place of and/or in conjunction with the shape described herein and achieve the desired functionality.
[0021] The arms 115 function as an interface with the user and allow the user to apply a force to move the upper portion 107 and lower portion 109 hingedly in opposing directions. Applying force to the arms 115 moves the upper portion 107 and lower portion 109 into a second position whereby the arms 115 are adjacent each other. The arms 115 have substantially disposed thereon a coating 117 . The coating 117 functions to provide a user grasping the arms 115 a secure method of grasping. The coating 117 is manufactured from a durable flexible material such as but not limited to rubber and is secured by conventional methods such as chemical adhesion.
[0022] Integrally extending from the first end 111 of the lower portion 109 and upper portion 107 and contiguous therewith are a pair of fingers 120 . The fingers 120 extend outward from the base 105 opposite the arms 115 . The fingers 120 are slightly arcuate in shape and function to grasp a plurality of suitable rigid support structures such as but not limited to a tabletop. Those skilled in the art will recognize that numerous different shapes of the fingers 120 could be utilized in place of and/or in conjunction with the fingers 120 as illustrated in the drawings submitted herewith and achieve the functionality suggested herein.
[0023] Still referring to FIG. 1 , the tips 125 of the fingers 120 are adjacent to each other when the walking aid retention device 100 is in its first position. The coil spring 110 functions to bias the opposing fingers 120 against each other. In its second position, the fingers 120 of the walking aid retention device 100 move outwardly from each other thereby allowing the introduction of a suitable rigid support structure therein.
[0024] The fingers 120 have substantially disposed thereon a coating 117 . The coating 117 functions to inhibit the fingers 120 from scratching any surface upon which the walking aid retention device 100 is attached. Furthermore, the coating 117 disposed on the fingers 120 functions to prevent the walking aid retention device 100 from slipping on the surface to which it has been temporarily secured. The coating 117 is manufactured from a suitable flexible material such as rubber or plastic and is fastened to the fingers 120 by conventional chemical methods such as chemical adhesives.
[0025] A resilient clamp 130 is to the base 105 intermediate the upper portion 107 and lower portion 109 . The resilient clamp 130 is positioned perpendicular with the base 105 . The resilient clamp 130 includes a base section 135 and a pair of legs 140 integrally extending therefrom, wherein the legs 140 flex outwardly for introduction of the body of a walking aid such as but not limited to a cane or crutch, and snap fits onto the exterior surface as the walking aid as it is firmly pushed therein.
[0026] The base section 135 and legs 140 are manufactured from a suitable resilient metal. The legs 140 are generally flange shaped with the end 137 distal the base section 135 of each leg 140 extending outward from the opposing leg 140 . The base section 135 is rotatably mounted to the base 105 by a conventional pin 142 . The base section 135 is mounted with the pin 142 that functions to permit the base section 135 to rotate approximately 360 degrees. This allows the walking aid that has been introduced into the resilient clamp 130 to be maintained in a generally vertical orientation regardless of the orientation of the surface upon which the walking aid retention device 100 has been temporarily secured.
[0027] The resilient clamp 130 has substantially disposed thereon a coating 117 that functions to prevent damage to the walking aid inserted thereinto. Secondly, the coating 117 functions to increase the adhesion of the resilient clamp 130 on the inserted walking aid. Although the resilient clamp 130 is shown as being rotatably attached to the base 105 and perpendicular thereto, it is contemplated within the scope of the present invention that the resilient clamp 130 could also be manufactured to hinge downward to be positioned adjacent to the base 105 to facilitate easier storage of the walking aid retention device 100 . It is further contemplated within the scope of the present invention that the resilient clamp 130 could be manufactured in numerous different sizes to accommodate a plurality of walking aids therein.
[0028] Now referring to FIG. 2 , the walking aid retention device 200 is illustrated attached to a structure 210 , such as a bench or chair. The fingers 220 function to grip the structure 210 and maintain the walking aid 220 in a generally vertical position while the user is not engaged with the walking aid 220 . The fingers 220 are manufactured to accommodate a plurality of surfaces such as but not limited to tabletops, benches and tubular handrails adjacent to toilets. The walking aid 220 is releasably secured into the resilient clamp 230 . The resilient clamp 230 is rotatably mounted to facilitate the walking aid 220 to be positioned in a vertical orientation regardless of the orientation of the structure 210 .
[0029] Still referring to FIG. 2 , a description of the operation of the walking aid retention device 200 is as follows. A walking aid 220 such as but not limited to a cane is inserted into the resilient clamp 230 of the walking aid retention device 200 . The user employs the walking aid 220 to assist the user in walking to a desired location such as a bathroom. The user positions the walking aid 220 adjacent to a suitable structure for securing the walking aid 220 . The user grasps the arms 215 and applies the required force to move the walking aid retention device 200 from its first position to its second position wherein the fingers 240 are separated by an appropriate distance to accommodate the desired support structure thereinto. The user inserts the desired structure thereinto the fingers 240 and releases the force from the arms 215 . The coil spring 250 biases the fingers 240 against the structure and the rotatable resilient clamp 230 allows the user to position the walking aid 220 in a generally vertical orientation. To release the walking aid 220 from the structure, the user applies the required force to the arms 215 in order to move the fingers 240 away from the adjacent structure placing the walking aid retention device 200 to its second position. The walking aid 220 is moved away from the structure and the user then releases the pressure on the arms 215 thereby returning the walking aid retention device to its first position. The user then proceeds to use the walking aid 220 as needed.
[0030] Although it is contemplated that the specific dimension of the walking aid retention device 200 can be adjusted base upon a user particular requirements, good results have been achieved with a walking aid retention device 200 that measures 4.5 inches in height, 6.5 inches in length and 2.25 inches in width. It is further contemplated within the scope of the present invention that the walking aid 200 could be integrally manufactured into the walking aid 220 . It is also contemplated within the scope of the present invention that the walking aid 200 could be manufactured in a variety of colors.
[0031] In the preceding detailed description, reference has been made to the accompanying drawings 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.
|
A walking aid retention device for releasably maintaining a walking aid in a generally vertical position and being configured to be attached to a suitable rigid structure. The walking aid retention device further includes a base portion with a pair of fingers extending therefrom designed to receive thereinto a suitable rigid support structure. Contiguous with the base and extending opposite the finger are a pair of arms. Attached to the base is a coil spring that biases the fingers towards each other. Perpendicularly mounted to the base is a resilient clamp having two legs that is rotatable and is configured to receive a walking aid thereinto.
| 0
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to fabrication methods of semiconductor packages, and more particularly, to a fabrication method of a semiconductor package for improving the product reliability.
[0003] 2. Description of Related Art
[0004] Along with the rapid development of electronic industries, electronic products are developed towards multi-function and high electrical performance. Accordingly, fan out packaging technologies have been developed to meet the miniaturization requirement of semiconductor packages.
[0005] FIGS. 1A to 1D are schematic cross-sectional views showing a fabrication method of a fan out semiconductor package 1 according to the prior art.
[0006] Referring to FIG. 1A , a carrier 10 is provided and an adhesive layer 11 is formed on the carrier 10 .
[0007] Then, a plurality of semiconductor elements 12 are disposed on the adhesive layer 11 . Each of the semiconductor elements 12 has an active surface 12 a with a plurality of electrode pads 120 and a non-active surface 12 b opposite to the active surface 12 a . The semiconductor elements 12 are attached to the adhesive layer 11 via the active surfaces 12 a thereof.
[0008] Referring to FIG. 1B , an encapsulant 13 is laminated on the adhesive layer 11 for encapsulating the semiconductor elements 12 .
[0009] Referring to FIG. 1C , a curing process is performed to cure the encapsulant 13 , and then the adhesive layer 11 and the carrier 10 are removed to expose the active surfaces 12 a of the semiconductor elements 12 .
[0010] Referring to FIG. 1D , an RDL (Redistribution Layer) process is performed to form an RDL structure 14 on the encapsulant 13 and the active surfaces 12 a of the semiconductor elements 12 . The RDL structure 14 is electrically connected to the electrode pads 120 of the semiconductor elements 12 .
[0011] Then, an insulating layer 15 is formed on the RDL structure 14 , and portions of the RDL structure 14 are exposed from the insulating layer 15 so as for a plurality of conductive elements 16 such as solder bumps to be mounted thereon.
[0012] However, large stresses may be generated during the curing process of the encapsulant 13 and dispersed by the carrier 10 . As such, referring to FIG. 1 D′, warpage easily occurs on edges of the encapsulant 13 after the carrier 10 is removed. Therefore, it becomes difficult for the RDL structure 14 to be aligned with the electrode pads 120 of the semiconductor elements 12 . The greater the size of the carrier 10 is, the more severe the position tolerance between the semiconductor elements 12 becomes, thereby adversely affecting the electrical connection between the RDL structure 14 and the semiconductor elements 12 . As such, the product reliability and yield are reduced.
[0013] Therefore, there is a need to provide a fabrication method of a semiconductor package so as to overcome the above-described drawbacks.
SUMMARY OF THE INVENTION
[0014] In view of the above-described drawbacks, the present invention provides a fabrication method of a semiconductor package, which comprises the steps of: providing a carrier; disposing at least a semiconductor element on the carrier, wherein the semiconductor element has an active surface with a plurality of electrode pads and a non-active surface opposite to the active surface, and the semiconductor element is disposed on the carrier via the active surface thereof; forming an encapsulant on the carrier and the semiconductor element for encapsulating the semiconductor element, wherein the encapsulant has a first surface bonded to the carrier and a second surface opposite to the first surface, and the encapsulant further has a pressure area defined around the semiconductor element; removing the carrier to expose the first surface of the encapsulant and the active surface of the semiconductor element; disposing at least a pressure member on the pressure area of the encapsulant; and forming an RDL structure on the active surface of the semiconductor element and the first surface of the encapsulant, wherein the RDL structure is electrically connected to the electrode pads of the semiconductor element.
[0015] In the above-described method, the pressure member can have a frame.
[0016] In the above-described method, two pressure members can be disposed on both the first surface and the second surface of the encapsulant, respectively. For example, the pressure area of the encapsulant can be sandwiched between the pressure members.
[0017] In the above-described method, the at least a pressure member can be made of an iron material or a magnetic body.
[0018] In the above-described method, the at least a pressure member can be disposed on only one of the first surface and the second surface of the encapsulant.
[0019] In the above-described method, the encapsulant can be formed by molding, thin film laminating or printing.
[0020] In the above-described method, the pressure area can be located on edges of the first or second surface of the encapsulant.
[0021] In the above-described method, if a plurality of semiconductor elements are provided, the pressure area can further be located between any two adjacent ones of the semiconductor elements.
[0022] The above-described method can further comprise forming on the RDL structure an insulating layer having a plurality of openings for exposing portions of the RDL structure.
[0023] The above-described method can further comprise performing a singulation process after forming the RDL structure, and the at least a pressure member can be removed through the singulation process.
[0024] According to the present invention, after the carrier is removed, the pressure member is disposed on the pressure area of the encapsulant for providing a support force to keep the structure flat, thereby mitigating warpge of the encapsulant.
[0025] As such, warpage of the encapsulant does not increase as the size of the carrier increases. Therefore, the RDL structure can be effectively aligned with and electrically connected to the semiconductor element so as to improve the product reliability and yield and reduce the fabrication cost.
BRIEF DESCRIPTION OF DRAWINGS
[0026] FIGS. 1A to 1D are schematic cross-sectional views showing a conventional fabrication method of a semiconductor package, wherein FIG. 1 D′ shows warpage of the structure of FIG. 1C ; and
[0027] FIGS. 2A to 2F are schematic cross-sectional views showing a fabrication method of a semiconductor package according to the present invention, wherein FIG. 2 D′ is an upper view of FIG. 2D , FIG. 2 D″ is an upper view showing another embodiment of FIG. 2D .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0028] The following illustrative embodiments are provided to illustrate the disclosure of the present invention, these and other advantages and effects can be apparent to those in the art after reading this specification.
[0029] It should be noted that all the drawings are not intended to limit the present invention. Various modifications and variations can be made without departing from the spirit of the present invention. Further, terms such as “upper”, “on”, “first”, “second” etc. are merely for illustrative purposes and should not be construed to limit the scope of the present invention.
[0030] FIGS. 2A to 2F are schematic cross-sectional views showing a fabrication method of a semiconductor package 2 according to the present invention.
[0031] Referring to FIG. 2A , a carrier 20 is provided, and a plurality of semiconductor elements 22 are array arranged on the carrier 20 .
[0032] In the present embodiment, the carrier 20 can be a wafer type substrate or a panel type substrate. The carrier 20 can have a base board 200 made of glass, and a release layer 201 and an adhesive layer 202 sequentially formed on the base board 200 . Each of the semiconductor elements 22 has an active surface 22 a with a plurality of electrode pads 220 and a non-active surface 22 b opposite to the active surface 22 a . The semiconductor elements 22 are attached to the adhesive layer 202 via the active surfaces 22 a thereof.
[0033] Referring to FIGS. 2 B and 2 D′, an encapsulant 23 is formed on the adhesive layer 202 of the carrier 20 and the semiconductor elements 22 for encapsulating the semiconductor elements 22 . The encapsulant 23 has a first surface 23 a bonded to the carrier 20 and a second surface 23 b opposite to the first surface 23 a . The encapsulant 23 further has a pressure area t defined around the semiconductor elements 22 .
[0034] In the present embodiment, the encapsulant 23 is made of a thin film and formed through laminating, or made of an adhesive material and formed through printing. In other embodiments, the encapsulant 23 can be made of a molding compound and formed through a molding process.
[0035] Generally, the encapsulant 23 needs to be cured through a heating process, thus increasing internal stresses of the encapsulant 23 . The internal stresses can be dispersed by the carrier 20 .
[0036] The pressure area t can be located on edges of the first surface 23 a or the second surface 23 b of the encapsulant 23 .
[0037] Further, the active surfaces 22 a of the semiconductor elements 22 are coplanar with the first surface 23 a of the encapsulant 23 .
[0038] Referring to FIG. 2C , the carrier 200 and the release layer 201 and the adhesive layer 202 on the carrier 200 are removed to expose the first surface 23 a of the encapsulant 23 and the active surfaces 22 a of the semiconductor elements 22 .
[0039] Referring to FIGS. 2 D and 2 D′, a pressure member 21 is disposed on the pressure area t of the encapsulant 23 .
[0040] In the present embodiment, the pressure member 21 is of a frame and has two portions respectively disposed on the first and second surfaces 23 a , 23 b of the encapsulant 23 . The two portions of the pressure member 21 are aligned with each other so as to sandwich the pressure area t of the encapsulant 23 between them. Preferably, the two portions of the pressure member 21 are made of an iron material or mutually attractive magnetic bodies. In another embodiment, the two portions of the pressure member 21 can be not aligned with each other.
[0041] In another embodiment, the pressure member 21 can be disposed on only one of the first surface 23 a and the second surface 23 b of the encapsulant 23 .
[0042] Referring to FIG. 2 D″, a pressure area t′ is further defined between the semiconductor elements 22 so as for the pressure member 21 to be disposed thereon.
[0043] According to the present invention, after the carrier 20 is removed, the pressure member 21 provides a support force to keep the structure flat, thereby mitigating warpage of the encapsulant 23 .
[0044] Referring to FIG. 2E , an RDL process is performed to form an RDL structure 24 on the active surfaces 22 a of the semiconductor elements 22 and the first surface 23 a of the encapsulant 23 . The RDL structure 24 is electrically connected to the electrode pads 220 of the semiconductor elements 22 .
[0045] In the present embodiment, the RDL structure 24 has a dielectric layer 240 formed on the first surface 23 a of the encapsulant 23 and the active surfaces 22 a of the semiconductor elements 22 , a circuit layer 241 formed on the dielectric layer 240 , and a plurality of conductive vias 242 formed in the dielectric layer 240 for electrically connecting the circuit layer 241 and the electrode pads 220 of the semiconductor elements 22 .
[0046] Thereafter, an insulating layer 25 is formed on the RDL structure 24 and has a plurality of openings for exposing portions of the circuit layer 241 . Then, a plurality of conductive elements 26 such as solder bumps are formed on the exposed portions of the circuit layer 241 .
[0047] The dielectric layer 240 can be made of polyimide (PI), benezocyclobutene (BCB) or polybenzoxazole (PBO).
[0048] In other embodiments, the RDL structure can have a plurality of dielectric layers 240 and a plurality of circuit layers 241 formed on the dielectric layers 240 .
[0049] Referring to FIG. 2F , a singulation process is performed along cutting paths S of FIG. 2E so as to obtain a plurality of semiconductor packages 2 . Also, the pressure member 21 is removed through the singulation process.
[0050] According to the present invention, the pressure member 21 is disposed on the pressure area t of the encapsulant 23 for providing a support force to keep the structure flat, thereby mitigating warpge of the encapsulant 23 .
[0051] Therefore, warpage of the encapsulant 23 does not increase as the size of the carrier 20 becomes larger. Accordingly, the conductive vias 242 of the RDL structure 24 can be effectively aligned with and electrically connected to the electrode pads 220 of the semiconductor elements 22 so as to improve the product reliability and yield and reduce the fabrication cost.
[0052] The above-described descriptions of the detailed embodiments are only to illustrate the preferred implementation according to the present invention, and it is not to limit the scope of the present invention. Accordingly, all modifications and variations completed by those with ordinary skill in the art should fall within the scope of present invention defined by the appended claims.
|
A fabrication method of a semiconductor package is disclosed, which includes the steps of: providing a carrier; disposing at least a semiconductor element on the carrier; forming an encapsulant on the carrier and the semiconductor element for encapsulating the semiconductor element; removing the carrier; disposing a pressure member on the encapsulant; and forming an RDL structure on the semiconductor element and the encapsulant, thereby suppressing internal stresses through the pressure member so as to mitigate warpage on edges of the encapsulant.
| 7
|
CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims priority from Japanese Patent Application No. JP2005-040793, filed Feb. 17, 2005, the entire disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic disk drive, and more particularly to a technique of improving the vibration characteristics of a magnetic disk drive and reducing its size.
In recent years, there has been a need to miniaturize magnetic disk drives such as hard disk drives. Some such magnetic disk drives employ a cantilever type spindle motor and a fluid bearing as shown in FIG. 11 .
The magnetic disk drive 100 includes: a motor shaft 101 for rotating a magnetic disk (not shown); a motor hub 102 into which the motor shaft 101 is press fit and which supports the magnetic disk; and a sleeve 103 for rotatably supporting the motor shaft 101 through oil X.
Since such a cantilever type magnetic disk drive 100 is susceptible to external vibrations, etc., the stiffness of the radial bearing has been increased to improve the vibration characteristics. See, e.g., Patent Document 1 (Japanese Patent Laid-open No. 2001-339899).
BRIEF SUMMARY OF THE INVENTION
The above conventional magnetic disk drive 100 must have a thickness large enough to accommodate the following lengths: the length Y 1 of the portion of the motor shaft 101 press fit into the motor hub 103 ; the length Y 2 of the oil buffer for holding the excess portion of the oil X held between the motor shaft 101 and the sleeve 103 ; and the length Y 3 of the radial bearing portion of the sleeve 103 for supporting the motor shaft 101 .
Therefore, there is a limit to the miniaturization of the above conventional magnetic disk drive 100 ; it is difficult to reduce the thickness of the drive.
The present invention has been devised in view of the above problems. It is, therefore, a feature of the present invention to provide a magnetic disk drive having improved vibration characteristics and a reduced size.
To solve the above problems, a magnetic disk drive according to an embodiment of the present invention comprises: a motor shaft for rotating a magnetic disk; a sleeve for rotatably supporting the motor shaft; and a motor hub into which the motor shaft is press fit, the motor hub supporting the magnetic disk and including a projection portion having an inner surface and an outer surface, the inner surface being in contact with the press-fit motor shaft in directions perpendicular to the rotational axis of the motor shaft, the outer surface facing the sleeve.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a first example of a magnetic disk drive according to an embodiment of the present invention, taken along the rotational axis P.
FIG. 2 is a cross-sectional view of the motor hub of the first example according to the embodiment, taken along the rotational axis P.
FIG. 3 is a cross-sectional view of the sleeve of the first example according to the embodiment, taken along the rotational axis P.
FIG. 4 is a cross-sectional view of the sleeve of the first example according to the embodiment, taken along the rotational axis P, wherein unbalancing grooves are formed in the buffer inner surface.
FIG. 5 is a cross-sectional view of a second example of the magnetic disk drive according to the embodiment, taken along the rotational axis P.
FIG. 6 is a cross-sectional view of the motor hub of the second example according to the embodiment, taken along the rotational axis P.
FIG. 7 is a cross-sectional view of the sleeve of the second example according to the embodiment, taken along the rotational axis P.
FIG. 8 is a cross-sectional view of the second example of the magnetic disk drive according to the embodiment, taken along the rotational axis P, wherein an oil circulation flow path is formed in the sleeve.
FIG. 9 is a plan view of the sleeve of the second example according to the embodiment, wherein the oil circulation flow path is formed in the sleeve.
FIG. 10 is a cross-sectional view of the sleeve shown in FIG. 9 taken along line H-H.
FIG. 11 is a cross-sectional view of a conventional magnetic disk drive.
DETAILED DESCRIPTION OF THE INVENTION
A description will be given below of a magnetic disk drive according to an embodiment of the present invention with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a first example of the magnetic disk drive (hereinafter referred to as disk drive 1 ) of the present embodiment.
As shown in FIG. 1 , the disk drive 1 includes: a motor hub 10 for supporting a magnetic disk (not shown); a motor shaft 20 press fit into the motor hub 10 ; and a sleeve 30 for rotatably supporting the press-fit motor shaft 20 through oil O.
Further, the disk drive 1 also includes a coil stator 40 and a magnet 41 which are disposed between the motor hub 10 and the sleeve 30 to generate a magnetic field for rotating the motor shaft 20 .
A characteristic of the disk drive 1 is that the motor hub 10 and the sleeve 30 are disposed such that the upper portion of the motor hub 10 and the sleeve 30 partially overlap each other in the direction of the rotational axis P of the motor shaft 20 . At least a portion of the length L 2 of the oil buffer A overlaps the length L 1 of the portion of the motor shaft 20 press fit into the motor hub 10 .
That is, the oil buffer A of the sleeve 30 is formed such that its upper surface is higher than the lowest point of the portion or hole of the motor hub 10 into which the motor shaft 20 is press fit. That portion of the motor hub 10 downwardly extends inside the oil buffer A in the direction of the rotational axis P of the motor shaft 20 .
FIG. 2 is a cross-sectional view of the motor hub 10 of the disk drive 1 . As shown in the figure, the motor hub 10 includes: a central portion 12 including the inner surface 11 of the hole B into which the motor shaft 20 is press fit; a top plate portion 13 having a disk shape and extending from the central portion 12 in directions approximately perpendicular to the rotational axis P; a side plate portion 14 downwardly extending from the outer circumference of the top plate portion 13 ; and a disk-receiving portion 15 extending from the lower end of the side plate portion 14 in directions approximately perpendicular to the rotational axis P and supporting the magnetic disk (not shown).
Further, the central portion 12 includes a projection portion 50 provided on its back surface side, that is, the side facing the sleeve 30 . The projection portion 50 downwardly extends from the back surface 16 of the top plate portion 13 .
The projection portion 50 has: a projection portion inner surface 51 in contact with the motor shaft 20 press fit into the hole B for press fitting in directions perpendicular to the rotational axis P; and a projection portion outer surface 52 facing a portion, described later, of the sleeve 30 .
The projection portion inner surface 51 constitutes a portion of the inner surface 11 of the hole B for press fitting opened at the center of the projection portion 50 . Further, the projection portion outer surface 52 is formed at an angle with the rotational axis P.
The length from the back surface 16 of the top plate portion 13 to the lowest point of the projection portion 50 , that is, the length L 3 of the projection portion 50 , is approximately equal to the length L 2 of the oil buffer A. In the disk drive 1 , a portion of the length L 2 of the oil buffer A overlaps the length L 3 of the projection portion 50 , as shown in FIG. 1 .
The length of the inner surface 11 of the hole B for press fitting is equal to the length L 1 of the portion of the motor shaft 20 press fit into the motor hub 10 and is the sum of the length L 4 from the central portion upper surface 17 to the top plate portion back surface 16 and the length L 3 of the projection portion 50 .
FIG. 3 is a cross-sectional view of the sleeve 30 of the disk drive 1 . As shown in the figure, the sleeve 30 has: a buffer inner surface 31 facing approximately parallel to the projection portion outer surface 52 ; and a bearing inner surface 32 for rotatably supporting the motor shaft 20 through the oil O.
Naturally, the dimension of the buffer inner surface 31 in the direction of the rotational axis P is equal to the length L 2 of the oil buffer A. Further, in the disk drive 1 , as shown in FIG. 1 , the buffer inner surface 31 forms a hole C for receiving therein the projection portion 50 having the length L 3 . That is, the disk drive 1 is configured such that the outer surface 52 of the projection portion 50 received within the projection-portion-receiving hole C and the buffer inner surface 31 facing the projection portion outer surface 52 form the oil buffer A therebetween.
Thus, the disk drive 1 includes: the projection portion inner surface 51 in contact with the motor shaft 20 press fit into the motor hub 10 in directions perpendicular to the rotational axis P; and the projection portion outer surface 52 and the buffer inner surface 31 facing each other and forming the oil buffer A therebetween.
Further, the bearing inner surface 32 is cylindrical and forms a bearing hole D into which the motor shaft 20 is inserted (see FIG. 1 ). In the disk drive 1 , the oil O is held between the bearing inner surface 32 and the motor shaft 20 inserted into the bearing hole D, as shown in FIG. 1 .
The bearing inner surface 32 includes a plurality of radial bearing regions 33 , 34 having grooves formed therein to generate dynamic pressure by the action of the oil O so as to rotatably support the motor shaft 20 and thereby function as a fluid bearing.
More specifically, the bearing inner surface 32 includes an upper radial bearing region 33 and a lower radial bearing region 34 spaced a predetermined distance apart along the direction of the rotational axis P.
In the lower portion having the length L 5 of the upper radial bearing region 33 , a plurality of balancing grooves E are formed to generate dynamic pressure by the action of the oil O. Further, in the upper portion having the length L 6 above the balancing grooves E, a plurality of unbalancing grooves F are formed such that they follow the balancing grooves E to prevent the oil O from leaving the bearing hole D or the oil buffer A. It should be noted that unlike the upper radial bearing region 33 , only balancing grooves E are formed in the lower radial bearing region 34 .
It should be further noted that unbalancing grooves F may be formed in the buffer inner surface 31 of the sleeve 30 , as shown in FIG. 4 . In this case, only the balancing grooves E need to be formed in the upper radial bearing region 33 of the bearing inner surface 32 , allowing the sleeve 30 to have the upper radial bearing region 33 at a higher position than shown in FIG. 3 . This makes it possible to more stably support the motor shaft 20 .
FIG. 5 is a cross-sectional view of a second example of the disk drive 1 . FIGS. 6 and 7 are cross-sectional views of the motor hub 10 and the sleeve 30 , respectively, of this example. It should be noted that the second example includes components of the first example. The detailed description of these components will not be repeated below.
In the second example, the motor hub 10 of the disk drive 1 includes a projection portion 50 having: a projection portion outer surface 52 approximately parallel to the rotational axis P; and a projection portion undersurface 53 approximately perpendicular to the rotational axis P and connecting between the projection portion outer surface 52 and the projection portion inner surface 51 (see FIGS. 5 and 6 ).
Further, the sleeve 30 of this disk drive 1 has: a buffer inner surface 31 approximately parallel to the projection portion outer surface 52 of the motor hub 10 ; and a buffer bottom surface 35 approximately parallel to the projection portion undersurface 53 (see FIGS. 5 and 7 ).
In this sleeve 30 , the projection-portion-receiving hole C is formed by the buffer inner surface 31 and the buffer bottom surface 35 .
In this disk drive 1 , the buffer inner surface 31 and the buffer bottom surface 35 of the sleeve 30 face the outer surface 52 and the undersurface 53 , respectively, of the projection portion 50 received within the projection-portion-receiving hole C; these surfaces form therebetween the oil buffer A for holding the oil O.
Also in the second example, the motor hub 10 and the sleeve 30 are disposed such that the upper portion of the motor hub 10 and the sleeve 30 partially overlap each other in the direction of the rotational axis P of the motor shaft 20 . At least a portion of the length L 8 of the oil buffer A overlaps the length L 7 of the portion of the motor shaft 20 press fit into the motor hub 10 . It should be noted that the sleeve 30 shown in FIG. 7 may have balancing grooves E and unbalancing grooves F as shown in FIGS. 3 and 4 .
Further, in this disk drive 1 , an oil circulation flow path G for circulating the oil O may be formed between the buffer inner surface 31 and the bearing inner surface 32 of the sleeve 30 , as shown in FIG. 8 .
FIG. 9 is a plan view of such a sleeve 30 , and FIG. 10 is a cross-sectional view taken along line H-H in FIG. 9 . In this sleeve 30 , the oil circulation flow path G is formed between the buffer inner surface 31 and the bearing inner surface 32 such that the path is located at points on the circumference of a circle concentric with the buffer inner surface 31 and the bearing inner surface 32 centered at the rotational axis P, as shown in FIG. 9 .
As shown in FIGS. 8 and 10 , the oil circulation flow path G is made up of through holes running downward from the buffer bottom surface 35 along the length L 9 of the bearing inner surface 32 . The oil circulation flow path G also functions to allow fine bubbles generated between the motor shaft 20 and the sleeve 30 to escape, for example.
In this disk drive 1 configured as described above, a magnetic field is generated between the magnet 41 fixed to the side plate portion 14 of the motor hub 10 and the coil stator 40 fixed to the sleeve 30 so as to face the magnet 41 , thereby integrally rotating the motor hub 10 , the magnetic disk supported by the disk-receiving portion 15 of the motor hub 10 , and the motor shaft 20 press fit into the motor hub 10 .
It should be noted that as the motor shaft 20 rotates, the oil O held between the motor shaft 20 and the sleeve 30 is gathered through the balancing grooves E formed in the radial bearing regions 33 and 34 of the bearing inner surface 32 , thereby generating dynamic pressure which allows the motor shaft 20 to float within the bearing hole D and rotate smoothly.
It is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.
|
Embodiments of the invention provide a magnetic disk drive having improved vibration characteristics and a reduced size. In one embodiment, a magnetic disk drive comprises: a motor shaft for rotating a magnetic disk; a sleeve for rotatably supporting the motor shaft; and a motor hub into which the motor shaft is press fit. The motor hub supports the magnetic disk and includes a projection portion having an inner surface and an outer surface. The inner surface is in contact with the press-fit motor shaft in directions perpendicular to the rotational axis of the motor shaft. The outer surface faces the sleeve.
| 5
|
This invention was made with government support under Contract N00014-86K-0766 awarded by the Department of Navy. The government has certain rights in the invention.
This is a division of application Ser. No. 193,964, filed May 13, 1988, now U.S. Pat. No. 5,079,334.
BACKGROUND OF THE INVENTION
The invention relates to the use of polyaniline or derivatives thereof for absorbing electromagnetic radiation, including microwaves, radar waves, infrared waves, visible light waves, and ultraviolet waves. The invention further relates to the use of the radiation absorbing polyaniline compositions to modulate another electromagnetic beam. The invention also relates to the modification of the electromagnetic response of polyaniline compositions by chemical or electrochemical means. The invention further relates to electronic and microelectronic devices based on the chemical and physical properties of polyaniline and its derivatives, and the control of the properties.
When a spectrum of radiant energy is directed into a sample of some substances, several things may happen to the energy: (1) it may pass through the sample with little absorption taking place and therefore, little energy loss. (2) The direction of propagation of the beam may be altered by reflection, refraction, or diffraction. Scattering of the beam by particulate suspended matter may also be involved. (3) The radiant energy may be absorbed entirely or in part. The absorption involves a transfer of energy to the medium, and the absorption process is a specific phenomenon related to characteristic molecular and electronic structures; the wavelengths of certain components of the radiation may be absorbed while others pass through essentially undisturbed, depending on the characteristics of the substance. Components of the radiation are absorbed if its energy matches that energy which is required to raise molecular or ionic components of the sample from one energy level to another. Those energy transitions may involve vibrational, rotational, or electronic states. After it has been absorbed, that energy may be emitted as fluorescence, utilized to initiate chemical reactions, or actually dissipated as heat energy.
When molecules interact with radiant energy in the visible and ultraviolet region, the absorption consists in displacing an outer electron in the molecule, although sometimes the energy of the far ultraviolet is sufficient to exceed the energy of dissociation of certain bonds.
The absorption of radiant energy is a highly specific property of the molecular structure, and the frequency range within which energy can be absorbed is specifically dependent upon the molecular structure of the absorbing material. The smaller the energy difference between the ground state and the excited electronic state, the lower will be the frequency of absorption (i.e., the longer the wavelength). Chemical compounds with only single bonds involving sigma-valency electrons exhibit absorption spectra only below approximately 150 millimicrons. In covalently saturated compounds containing heteroatoms, such as nitrogen, oxygen, sulfur, and halogen, unshared p-electrons are present in addition to sigma electrons. Excitation promotes a p-orbital electron into an antibonding sigma orbital, such as occurs in ethers, amines, sulfides, and alkyl halides. In unsaturated compounds absorption results in the displacement of pi-electrons. Molecules containing single absorbing groups, called chromophores, undergo electronic absorption transitions at characteristic wavelengths, and the intensity of the absorption will be proportional to the number of that type of chromophore present in the molecule. Marked bathochromic shifts (absorption at longer wavelengths) occur when --OH, --NH 2 , and --SH, for example, replace hydrogen in unsaturated groups.
It is desirable for certain applications to have a material whose radiation absorption characteristics and index of refraction can be easily and reversibly modulated. Various polymeric materials have been investigated including polyacetylene, polymethylacrylonitrile, pyrazoline, tetracyanoethylene, tetracyanonaphthoquinodimethane, tetracyanoquinodimethane, polydiacetylene, polypyrrole, poly(N-methyl-pyrrole), polyphenylene vinylene, and polythiophene. Some of these polymeric materials are known to exhibit photoresponsive effects, but the materials have deficiencies when considered for certain electromagnetic applications. For example, polyacetylene and polydiacetylene are nonaromatic, possess unacceptable absorption band gaps, have limited photoresponse, are air sensitive, generally cannot be derivatized, and are not readily soluble and therefore cannot be easily deposited as a thin film from solution. In addition, most materials previously investigated for electromagnetic radiation absorption are not readily tunable, i.e., the photoresponses of the materials cannot be reversibly modulated by an external source of energy.
Organic polymers have long been studied for electronic transport and, more recently, for optical properties. The first organic polymers prepared were electrically insulating with conductivities as low as 10 -14 (ohms cm) -1 . The insulating properties are the result of all the electrons in the polymer being localized in the hybrid-atom molecular orbital bonds, i.e. the saturated carbon framework of the polymer. These insulators, which include polymers such as poly(n-vinylcarbazole), or polyethylene, have extremely large band gaps with energy as high as 10 eV required to excite electrons from the valence to the conduction band. Electrical applications of insulating organic polymers are limited to insulating or supporting materials where low weight and excellent processing and mechanical properties are desirable.
High electrical conductivity has been observed in several conjugated polymer or polyene systems. The first and simplest organic polymer to show high conductivity was "doped" polyacetylene In the "doped" form its conductivity is in excess of 200 (ohm cm) -1 . Although polyacetylene was first prepared in the late 1950's, it was not until 1977 that this polyene was modified by combining the carbon chain with iodine and other molecular acceptors to produce a material with metallic conductivity.
Polyaniline is a family of polymers that has been under intensive study recently because the electronic and optical properties of the polymers can be modified through variations of either the number of protons, the number of electrons, or both. The polyaniline polymer can occur in several general forms including the so-called reduced form (leucoemeraldine base), possessing the general formula ##STR2## the partially oxidized so-called emeraldine base form, of the general formula ##STR3## and the fully oxidized so-called pernigraniline form, of the general formula ##STR4##
In practice, polyaniline generally exists as a mixture of the several forms with a general formula (I) of ##STR5##
When 0<y<1 the polyaniline polymers are referred to as poly(paraphenyleneamineimines) in which the oxidation state of the polymer continuously increases with decreasing value of y. The fully reduced poly(paraphenyleneamine) is referred to as leucoemeraldine, having the repeating units indicated above corresponding to a value of y=1. The fully oxidized poly(paraphenyleneimine) is referred to as pernigraniline, of repeat unit shown above corresponds to a value of y=0. The partly oxidized poly(paraphenyleneimine) with y in the range of greater than or equal to 0.35 and less than or equal to 0.65 is termed emeraldine, though the name emeraldine is often focused on y equal to or approximately 0.5 composition. Thus, the terms "leucoemeraldine", "emeraldine" and "pernigraniline" refer to different oxidation states of polyaniline. Each oxidation state can exist in the form of its base or in its protonated form (salt) by treatment of the base with an acid.
The use of the terms "protonated" and "partially protonated" herein includes, but is not limited to, the addition of hydrogen ions to the polymer by, for example, a protonic acid, such as mineral and/or organic acids. The use of the terms "protonated" and "partially protonated" herein also includes pseudoprotonation, wherein there is introduced into the polymer a cation such as, but not limited to, a metal ion, M + . For example, "50%" protonation of emeraldine leads formally to a composition of the formula ##STR6## which may be rewritten as ##STR7##
Formally, the degree of protonation may vary from a ratio of [H + ]/[--N═]=0 to a ratio of [H + ]/[--N═]=1. Protonation or partial protonation at the amine (--NH--) sites may also occur.
The electrical and optical properties of the polyaniline polymers vary with the different oxidation states and the different forms. For example, the leucoemeraldine base, emeraldine base and pernigraniline base forms of the polymer are electrically insulating while the emeraldine salt (protonated) form of the polymer is conductive. Protonation of emeraldine base by aqueous HCl (1M HCl) to produce the corresponding salt brings about an increase in electrical conductivity of approximately 10 10 ; deprotonation occurs reversibly in aqueous base or upon exposure to vapor of, for example, ammonia. The emeraldine salt form can also be achieved by electrochemical oxidation if the leucoemeraldine base polymer or electrochemical reduction of the pernigraniline base polymer in the presence of an electrolyte of the appropriate pH. The rate of the electrochemical reversibility is very rapid; solid polyaniline can be switched between conducting, protonated and nonconducting states at a rate of approximately 10 5 Hz for electrolytes in solution and even faster with solid electrolytes (E. Paul, et al., J. Phys. Chem. 1985, 89, 1441-1447) The rate of electrochemical reversibility is also controlled by the thickness of the film, thin films exhibiting a faster rate than thick films. Polyaniline can then be switched from insulating to conducting form as a function of protonation level (controlled by ion insertion) and oxidation state (controlled by electrochemical potential). Thus, in contrast to, for example, the polypyrrole mentioned above, polyaniline can be turned "on" by either a negative or a positive shift of the electrochemical potential, because polyaniline films are essentially insulating at sufficiently negative (approximately 0.00 V vs. SCE) or positive (+0.7 V vs. SCE) electrochemical potentials. Polyaniline can also then be turned "off" by an opposite shift of the electrochemical potential.
The conductivity of polyaniline is known to span 10 orders of magnitude and to be sensitive to pH and other chemical parameters. It is well known that the resistance of films of both the emeraldine base and 50% protonated emeraldine hydrochloride polymer decrease by a factor of approximately 3 to 4 when exposed to water vapor. The resistance increases only very slowly on removing the water vapor under dynamic vacuum. The polyaniline polymer exhibits conductivities of approximately 1 to 5 Siemens per centimeter (S/cm) when approximately half of its nitrogen atoms are protonated. Electrically conductive polyaniline salts, such as fully protonated emeraldine salt [(--C 6 H 4 --NH-- C 6 H 4 --NH + )--Cl - ] x , have high conductivity (10 -4 to 10 +2 S/cm) and high dielectric constants (20 to 200) and have a dielectric loss tangent of from below 10 -3 to approximately 10 1 . Dielectric loss values are obtained in the prior art by, for example, carbon filled polymers, but these losses are not as large as those observed for polyaniline.
Polyaniline has been used to coat semiconductor photoelectrodes, to serve as an electrochromatic display material, and to suppress corrosion of iron.
While the preparation of polyaniline polymers and the protonated derivatives thereof is known in the art, it is novel herein to use these compositions for the attenuation of electromagnetic radiation, particularly microwaves, radar waves, infrared waves, visible waves, and ultraviolet waves. A need exists for a polymeric material which can be designed to absorb microwaves, radar waves, infrared waves, visible waves, and ultraviolet waves. In addition, a need exists for a method of absorbing the electromagnetic radiation to modulate another electromagnetic beam. A need also exists for a method for the modification of the electromagnetic properties of polyaniline compositions by chemical or electrochemical means.
SUMMARY OF THE INVENTION
The present invention relates to the use of polyaniline or derivatives thereof for absorbing electromagnetic radiation, including microwaves, radar waves, infrared waves, visible waves, and ultraviolet waves as needed. The invention further relates to the use of the radiation-absorbing polyaniline compositions to modulate another electromagnetic beam. The invention also relates to the modification of the electrical and optical properties of polyaniline compositions by chemical or electrochemical means. The invention further relates to electronic and microelectronic devices based on the chemical and physical properties of polyaniline and its derivatives.
While the invention relates to both microwave responses and nonlinear optical responses of polyaniline and its derivatives, the inventors believe that these phenomena are of different physical origins. The photoresponse is believed to be the result of the reorganization of chemical bonds and to be microscopic. The time frame is believed to be approximately 10 -13 to 10 -12 seconds (a rate of 10 12 to 10 13 Hz). The use of polyaniline compositions to achieve the microwave attenuation of the present invention, however, is believed to be due to a local reorganization of the electronic density on the order of 10 1 to 10 2 Angstroms and on a time frame of approximately 10 -10 seconds. Both the photoresponse and the microwave attenuation phenomenae are believed to be due to the absorption of electromagnetic radiation by the pi electron systems of the polyaniline polymer and its derivatives.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-7 illustrate alternative embodiments of the invention utilizing the optical properties.
FIGS. 8-11 illustrate waveguides utilizing the microwave absorption properties of the invention for absorbing microwaves propagated through the waveguide. FIG. 12 illustrates an alternative embodiment in which a surface is coated with a material embodying the present invention for preventing microwave reflections from the coated material.
FIGS. 13 and 14 illustrate alternative embodiments in which a microwave strip conductor is coated with material embodying the present invention.
FIGS. 15 and 1 illustrate microwave strip embodiments including an electrolyte for the controlled variation of the microwave absorption properties along the propagation axis of the microwave strip conductors.
FIGS. 17 and 18 illustrate embodiments utilizing thermally responsive films which have materials embodying the present invention distributed within the film.
FIG. 19 is a graphical plot illustrating the variation of the loss tangent as a function of protonation.
DETAILED DESCRIPTION
The dielectric loss of the polyaniline polymeric compositions can, according to the present invention, be controlled by the design of the chemical composition of the polyaniline polymer, the oxidative state of the polymer, and the degree of doping, including but not limited to, protonation and pseudoprotonation of the polymer. Thus, by the addition of electron-withdrawing or electron-donating groups to the nitrogen atoms and/or to the C 6 rings of the leucoemeraldine, emeraldine, or pernigraniline polyaniline compositions, the dielectric loss tangent can be varied. For example, addition of a methyl group to each C 6 ring to form poly(ortho-toluidine) leads to a dielectric loss tangent that can be varied from 10 -2 to 10 0 . By the present invention dielectric loss tangents can be varied from 10 -2 to approximately 20 by varying the form of the polyaniline, the degree, site and type of substituents. In the prior art, carbon filled silicone rubber or carbon filled epoxy paints or carbon bonded to fabric produce non-magnetic dielectric losses at microwave frequencies. A preferred embodiment of the present invention for attaining maximum dielectric loss is the emeraldine salt, wherein y is in the range of from approximately 0.4 to 0.6 and the protonation is approximately one proton per imine nitrogen, i.e., [H + ]/[--N═] is equal to approximately one.
The addition of electron-withdrawing or electron-donating groups to the polyaniline composition can facilitate the design of a polymeric material with desired absorption and transmission bands. Known electron-donating groups to be substituted onto the C 6 ring and operative in the present invention can include, but are not limited to, --OCH 3 , --CH 3 , halogens (electron-donating by way of a resonance effect), --NR 2 , --NHCOR, --OH, --O--, --SR, --OR, and --OCOR. These groups or atoms possess one or more unshared electron pairs on the atom adjacent to the ring. Known electron-withdrawing groups can include halogens (electron-withdrawing by way of an inductive effect), --NO 2 , --COOH, --COOR, --COR, --CHO, and --CN. Thus, the addition of electron-donating groups to the rings of polyaniline augments the charge delocalization. The added opportunities for resonance stabilization of the pi to pi* excited stat provided by electron-donating groups causes a marked lowering in the requirement for excitation energy, and thus a decreased frequency (longer wavelength) of absorption. Conversely, the addition of electron-withdrawing groups diminishes the opportunities for resonance stabilization, causing an increase in the requirement for excitation energy, and thus an increased frequency (shorter wavelength) of absorption. Thus, for example, protonation of --NH 2 changes it to --NH 3 +; this group no longer has an unshared pair of electrons to participate in charge delocalization. Alteration of --OH to the ion, --O - , provides further opportunity for participation of unshared electrons on oxygen in charge delocalization. Thus, the change of H to NH 2 is bathochromic; NH 2 to NH 3 + is hypschromic; OH to O - is bathochromic; and both of the changes, OH to OCOCH 3 and NH to NHCOCH 3 (acetylation), are hypsochromic.
The electron-withdrawing or electron-donating group can be present on the C 6 rings or the nitrogen atoms of the polyaniline composition at any desired percentage of the available sites. The electron-withdrawing or electron-donating groups are added to the C 6 ring sites or the nitrogen atom sites by chemical techniques known to those skilled in synthetic organic chemistry.
In this manner, a polyaniline composition is prepared which when produced in a flexible sheet form or which is coated onto a flexible substrate can be used to absorb electromagnetic radiation. Thus, a means of rendering an object undetectable to electromagnetic radiation such as radar is produced by the present invention by draping over the object the flexible polyaniline film or the coated flexible substrate, such as a cloth fabric or fishnet. Furthermore, by coating electromagnetic radiation-absorbing polyaniline compositions onto fibers, and then producing woven or non-woven fabrics from the coated fibers, cloth or clothing which is radiation absorbing could be produced, according to the present invention. In another embodiment, fibers of polyaniline itself or a derivative thereof, or fibers of polyaniline copolymerized with another polymer can be drawn or extruded and subsequently woven into electromagnetic radiation absorbing fabric, garments, coverings, and the like. In this manner radar absorbing clothing can be produced.
A further advantage of the present invention is that the polyaniline compositions and derivatives thereof have, or can be designed to have, desired processability in terms of, for example, viscosity, flexural strengths, solubility, adhesion to substrates, crosslinking, melting point, weight, adaptability to filler loading and the like. This is achieved by varying as desired the degree of protonation, the state of oxidation, and the type and degree of substituents on the polymer. Certain substituents may be preferred for the facilitation of desired processing parameters, such as increasing or decreasing solubility, altering extrusion parameters (rheology), achieving a specific viscosity, and the like. Derivatization is also useful for achieving compatibility with a copolymer, facilitating the tunability of the polyaniline composition for non-linear optics applications, and for specific wavelength absorption, such as microwave attenuation or a particular photoresponse.
The polyaniline compositions useful in the present invention can be coated by a variety of techniques onto substrates of choice. The polyaniline polymers can be applied to substrates according to the present invention by spray coating, dip coating, spin casting, transfer roll coating, brush-on coating, and the like. The polyaniline polymers can also be electrochemically deposited onto conductive substrates by known electrochemical deposition techniques.
According to the present invention, polyaniline can also be entrained within a matrix of, or copolymerized with, another polymer material to thereby produce a blend or a composite. Thus, polyaniline could be dispersed in, for example, polyethylene, polyimide, cellulose nitrate, and the like, and also can be coated onto fibrous materials. In addition, derivatization of the polyaniline compositions can enhance compatibility and processability of the polymer with other polymers.
In addition, the polyaniline compositions can be cast as thin films from a solvent solution, and the solvent evaporated to produce free standing films. The polyaniline films can be stacked as a composite with other polyaniline films, with films of polyaniline copolymerized with another polymer, or with non-polyaniline polymers and/or copolymers. Depending on the desired type and degree of substitution of the polyaniline with various crosslinkable functional moieties, the films produced can be cured in deeper sections, that is, thicker films or articles can also be produced by known polymer preparation techniques. Such thicker polyaniline materials will have some utility in certain non-linear optics applications, but will be even more preferred in certain radiation absorption applications, such as microwave attenuation.
Polyaniline will absorb electromagnetic radiation in the visible spectrum, in the infrared range, and in the ultraviolet range. Thus, the present invention further relates to a method of absorbing infrared, visible, or ultraviolet waves comprising exposing the polyaniline to infrared, visible, or ultraviolet waves, whereby the infrared, visible, or ultraviolet waves are absorbed by the polyaniline. The present invention also relates to a method for absorbing microwave radiation comprising exposing polyaniline to microwave radiation, whereby the microwave radiation is absorbed by the polyaniline.
Because polyaniline compositions are shown by the present invention to absorb electromagnetic radiation, another object of the invention is electromagnetic shielding. A thin film of polyaniline within, for example, the walls of television sets, computers, electronic machinery, and places for the storage of electronic data, such as computer semiconductor memories, will effectively absorb continuous and intermittent electromagnetic radiation from wires, coils, cathode tubes, etc. Protection against unwanted or unknown electronic surveillance of rooms can be achieved by the application of polyaniline to the walls, floor, and ceiling. Similarly, electrical wires can be shielded by the incorporation of a layer of polyaniline material into the plastic insulator coating on the wires with the advantage of grounding and static free property.
In addition, polyaniline can be used to make a remote thermal switch by exposing the polyaniline composition to microwave radiation. The polyaniline composition absorbs the radiation, which heats up the polyaniline, which in turn, can trigger a thermocouple placed in contact with the polyaniline composition. Upon removal of the source of microwaves, the polyaniline composition will cool and cause the thermocouple to switch back. By this manner a thermal switch is produced.
Thus, the present invention relates to a composition for absorbing electromagnetic radiation, wherein said electromagnetic radiation possesses a wavelength generally in the range of from about 1000 Angstroms to about 50 meters, wherein said composition comprises a polyaniline composition of the formula I, above, or a protonated salt thereof, where y is in the range of approximately 0.2 to 0.8, and the degree of protonation, i.e., x=[H + ]/[--N═], varies from x=0 through x=1.
The instant invention further relates to a method of applying heat to a substrate, said method comprising the steps of:
(a) applying to a substrate a microwave radiation-absorbing polyaniline composition, or a partially protonated salt thereof;
(b) exposing the microwave radiation-absorbing polyaniline composition, for example, a partially protonated salt thereof, to microwave radiation, whereby the microwave radiation-absorbing polyaniline composition, or the partially protonated salt thereof, absorbs the microwave radiation, resulting in the generation of thermal energy within the polyaniline composition. This heat can be localized, transferred from the polyaniline composition or the salt to a substrate and utilized to accomplish desired results, such as, but not limited to, joining of materials. Thus, two materials which have been placed in contact or close proximity with each other and in contact with a polyaniline composition can be adhered to each other upon the exposure of the polyaniline composition to sufficient microwave radiation to heat and thus melt or at least soften at least one of the materials to enable fusing. The frequency, duration and/or intensity of the microwave radiation necessary to achieve the desired adhesion of the two materials will vary depending on the nature of the materials to be adhered and on the degree and type of protonation and/or substitution, if any, on the polyaniline. The preferred frequency of the microwave radiation to be absorbed by the polyaniline compositions to thereby induce localized heating is from about 10 9 Hz to about 10 11 Hz. The polyaniline composition can be applied to one or both of the materials in any pattern, such as a grid pattern, stripes, spots, or the like as desired. The polyaniline can be applied via solution coating, adhesion of films, vapor deposition, extrusion of gels containing polyaniline, and other known application techniques.
In a preferred embodiment of the present invention directed toward the adhering of two or more materials by the absorption of microwave radiation by polyaniline, at least one of the materials to be adhered is a plastic. In another embodiment of the present invention one of the materials to be adhered is a silicate-containing material, such as, for example quartz or glass. In this manner, a plastic can be adhered to a glass fiber, such as an optical fiber, by means of exposure of the polyaniline to microwave radiation.
According to the present invention, polyaniline compositions can also be utilized to absorb radar waves possessing a wavelength in the general range of from about 0.01 cm to about 100 cm. The absorption of radar waves by the polyaniline composition would assist in rendering objects coated with the polyaniline composition relatively invisible to radar detection. Therefore, the instant invention further relates to a method for absorbing radar waves comprising exposing a polyaniline composition or a partially protonated salt thereof to radar waves whereby the polyaniline composition or the salt thereof absorbs at least some of the radar waves. The invention further relates to a method for reducing the detectability by radar of an object comprising applying to the object a polyaniline composition or a partially protonated salt thereof in an amount sufficient to absorb at least some, and preferably all, radar radiation to which the object may be exposed.
In a preferred embodiment of the method for reducing the detectability by radar of an object it is desirable to coat the object in such a way as to produce a gradient of absorption to minimize reflectance. Such a gradient of polyaniline material can be achieved by varying the degree of protonation of the polymer or the degree of substitution on either the C 6 ring or the nitrogen atoms or both with a chemical substituent such that an incoming radar beam first encounters a polyaniline composition with little or no protonation, i.e., a material with limited absorption of radiation. As the beam further advances along the gradient of polyaniline material covering the object, the beam encounters polyaniline polymer with continually increasing degrees of protonation, and hence increasing degrees of electromagnetic absorption. In this manner, little or no reflection of the beam is produced and the object is not detectable by a radar wave reflection.
The present invention further relates to a method of electrochemical switching of the polymeric state of a polyaniline composition. By contacting the polyaniline composition with an electrolyte, electrochemical switching of the polymeric state can be significantly accelerated, being accomplished on a time scale of approximately 10 -5 seconds. By contacting the polyaniline composition with a solid electrolyte, electrochemical switching of the polymeric state can be even further accelerated, being accomplished on a time scale of less than approximately 10 -7 seconds. For electromagnetic radiation absorption, such as the absorption of microwave radiation, electrochemical switching of the polymeric state can turn the polymeric material from radiation transparent to radiation absorbing, or vice versa, depending on the nature and direction of the electrochemical switching. For non-linear optics, electrochemical switching can change the important absorption and/or transmission bands for the probe and modulator beams, such as, for example, in switching from the emeraldine base form to the emeraldine salt form of polyaniline. The range of the absorption bands for the base and the salt can be shifted bathochromically (i.e., shifted to longer wavelengths) or hypsochromically (i.e., shifted to shorter wavelengths) as may be desired according to the characteristics of the available probe beam, the available modulator beam, or the available detector or sensor, or any combination thereof.
Polyaniline compositions can also be used according to the present invention as a photoactive switch by manipulation of the index of refraction of the polyaniline compositions. Because of the extremely rapid photoresponse of the polyaniline polymer, it is therefore useful according to the present invention in nonlinear optical devices. The time dependence of the photo bleaching of the polymer is on the order of picoseconds. For example, the application of a laser beam of wavelength 6250 Angstroms (2.0 eV) to polyaniline polymer produces significant photoinduced bleaching (i.e., increased transmission) in broad energy bands of 8,265 Angstroms to 4,590 Angstroms (approximately 1.5 eV to 2.7 eV) and again at 3,760 Angstroms to 2,880 Angstroms (approximately 3.3 eV to 4.3 eV). Simultaneously laser beam photoinduced absorption (i.e., decreased transmission) for polyaniline occurs at 24,800 Angstroms to 8,265 Angstroms (approximately 0.5 eV to 1.5 eV) and from 4,590 Angstroms to 3,760 Angstroms (2.7 eV to 3.3eV). Photoinduced absorption and bleaching occur in polyaniline compositions in less than 10 -12 seconds. These photoinduced changes in absorption correspond to changes in the index of refraction at these wavelengths. These changes in optical constants have broad application in nonlinear optical signal processing and optical communications, which according to the present invention, are useful as means to switch, modulate, multiplex, focus, and provide optical bistability for commercial systems.
Polyaniline is therefore useful in nonlinear optical signal processing according to the present invention. For example, a thin film coating of polyaniline can be applied to a phototransmissive substrate. In one embodiment of the present invention, a probe beam of light of a given wavelength is then propagated through the noncoated side of the substrate onto the coating at the critical angle to the polyaniline such that the probe beam is wave-guided in the phototransmissive substrate. To activate the desired switching property of the polyaniline coating, a pump beam of light, also called a modulator beam, of a different wavelength or some wavelength is applied to the coating through the coated or noncoated side of the substrate at a second angle such that the index of refraction of the polyaniline composition is changed by the absorption by the polyaniline of the electromagnetic radiation of the modulator beam. The wavelength of the modulator beam can vary widely, but is preferably within the range of from about 12,100 Angstroms (1.5 eV) to about 21,775 Angstroms (2.7 eV). The change in the refractive index of the polyaniline composition coating alters the transmissive property of the polyaniline and allows the probe beam to be refracted or otherwise modified by the polyaniline coating. This refraction or other modification of the probe beam can, for example, be used to trigger a photocell, initiate or terminate an optical signal, encode information on the probe beam, or the like. By these means is produced a low cost, stable means of optical signal processing.
In an alternative embodiment, the beam to be modulated is refracted by the phototransmissive substrate and reflected off the polyaniline coating on the backside of the substrate such that the beam is then reflected repeatedly between the front side of the substrate and the polyaniline coated back side of the substrate. This reflection continues within the phototransmissive substrate until the modulating beam is caused to impinge on the polyaniline coating, whereby the index of refraction of the polyaniline coating is altered by the absorption of the electromagnetic radiation of the modulator beam, altering the propagation of the probe beam. In this manner the polyaniline coating has acted as a switch which is reversibly controlled by the presence of the pump or modulating beam to increase or decrease the modulation (both intensity and direction) of the probe beam. Because of the very rapid photoresponse rate of the polyaniline polymer, the refractive index can be altered at gigahertz to terrahertz rates, thereby providing a method for the rapid modulation of optical data signals.
In yet another preferred embodiment, the beam to be modulated is caused to impinge upon a thin coating of polyaniline which is on a phototransmissive substrate. A portion of the beam is reflected, the remainder refracted, transmitted, and partly absorbed Application of a modulator beam at a second angle changes the index of refraction of the polyaniline thereby altering the direction and the percentage of the probe beam transmitted and reflected. The preferred embodiment has the probe beam incident on the polyaniline at the critical angle and the modulator beam preferably of wavelength between 12,100 Angstroms (1.5 eV) and 21,800 Angstroms (2.7 eV).
Thus, the present invention further relates to a method of changing the refractive index of polyaniline comprising the steps:
(a) applying polyaniline to a phototransmissive substrate;
(b) applying a first beam of light of wavelength x at the critical angle y to the polyaniline surface; and
(c) applying a second beam of light of wavelength z to the polyaniline surface, whereby the second beam is absorbed by the polyaniline changing the index of refraction of the polyaniline, whereby the transmission of the first beam through the phototransmissive substrate is altered. The preferred wavelength x of the first or probe beam of light is dependent on the form of polyaniline utilized. For emeraldine base polymer, the preferred wavelength x of the first or probe beam of light is in one or more of the ranges of approximately 0.6 eV to 4.2 eV; 0.8 to 1.1 eV; 1.6 to 2.4 eV; 2.8 to 3.2 eV; and 3.4 to 4.3 eV. The preferred wavelengths will vary depending on the degree of protonation of the polyaniline polymer and the nature of the substituents, if any, on the polymer. For the emeraldine base polymer, the preferred wavelength z of the second or modulating beam of light is in the range of approximately 1.7 eV to 2.7 eV. The preferred wavelength of the second or modulating beam is determined by the oxidation state, protonation level, and substituents of the polymer. For the leucoemeraldine polymer the preferred wavelengths of the probe beam are in the range of 24,800 Angstroms to 8,265 Angstroms (0.5 to 1.5 eV) and 4,590 Angstroms and 3,760 Angstroms, with greater preferred modulator beam wavelength of 3,760 Angstroms to 2,880 Angstroms. For pernigraniline, the preferred probe and modulator wavelength are similar to emeraldine.
The photoswitching phenomenon can, according to the present invention, also be used to couple a light signal from one optical fiber to another optical fiber. The two optical fibers are positioned in close contact with each other and with a thin film of polyaniline composition between them. The polyaniline composition is then exposed to a modulating beam. The modulating beam changes the index of refraction of the polyaniline such that "crosstalk" between the two optical fibers is obtained. This allows the optical signal within either of the optical fibers to be coupled to the other fiber as desired, but without permanent physical alteration of either fiber. In addition, the coupling can be turned on and off as desired by the manipulation of the index of refraction and, because of the very rapid photoresponse rate of the polyaniline polymer, the refractive index can be altered and coupling achieved at gigahertz to terrahertz rates.
In yet another embodiment of the present invention the polyaniline composition can itself be utilized simultaneously as the phototransmissive material and a photoswitch without a phototransmissive substrate. Thus, a free standing polyaniline polymer can be exposed to a first beam of light which will be transmitted through the polyaniline with some attenuation. When the polymer is exposed to a second or modulator beam the refractive index and absorption coefficient of the polyaniline polymer are altered, changing the intensity and angle of refraction of the beam transmitted through the polymer.
Another embodiment of the present invention is the use of polyaniline compositions as a masking material over ultraviolet-curable polymers in the fabrication of positive resist and negative resist microelectronic devices and circuits. In the fabrication of certain positive resist and negative resist microelectronic devices and circuits, radiation curable polymers are deposited on conductive or semiconductive surfaces, such as silicon or doped silicon. A circuit pattern is then applied by means of photolithographic techniques and covered by ultraviolet-curable polymers in certain desired patterns. Ultraviolet radiation is then applied to the polymers to cure certain portions, after which the uncured portions are removed by solvent rinsing, for example. In this manner, patterns of cured polymer are provided on the conductive or semiconductive surfaces. By the present invention, polyaniline can be applied to the curable polymer in a predetermined pattern such that the polymer beneath the polyaniline pattern is desired to remain uncured upon exposure of the coated device or circuit to radiation. When the polymer is exposed to the radiation, the polyaniline would absorb the ultraviolet radiation to thereby mask the polymer and prevent the cure in certain locations of the curable polymer beneath.
Thus, the present invention relates to a method for masking a radiation curable polymer applied to an electronic circuit or device, said method comprising the steps of (a) applying a radiation-curable polymer or prepolymer to an electronic device or circuit; (b) applying to the radiation-curable polymer or prepolymer a polyaniline composition; (c) exposing the device or circuit with the curable polymer or prepolymer and the polyaniline composition to radiation sufficient to cure the curable polymer or prepolymer and whereby the polyaniline composition absorbs some of the ultraviolet radiation; and (d) removing the polyaniline and any uncured curable polymer or prepolymer. In a preferred embodiment of the invention, the curable polymer or prepolymer and the polyaniline are independently deposited onto the surface of the electronic device or circuit by means of a solvent solution of each material, followed by the evaporation of the solvent. By "cure" herein is meant sufficient coreaction and/or crosslinking reactions have taken place to render the material a solid not easily removed by solvent.
We have developed a series of devices which utilize the features, characteristics and properties of the polyaniline compounds which are described above. First is a series of optical devices and second a series of microwave devices.
The optical devices are useful in a range of the electromagnetic spectrum at or near what is commonly referred to as light. These devices utilize the fact that the index of refraction of the polyaniline compounds may be controlled by varying the intensity and wavelength of light radiated upon the polyaniline compound. Thus, a pumping or modulating light at one or a broad band of frequencies may be used to modulate the index of refraction of the polyaniline compound and thereby modulate light at another frequency. For example this can be used for the coupling of the modulated light from one light transmissive medium to another or modulating its angle of departure from an interface between two light transmitting media. The spectral response of this photo effect is substantially changed as the compounds are more fully protonated with the largest response in the unprotonated material. Thus, the unprotonated polyaniline bases are preferred for some applications.
We have devised devices which can operate as various types of light valves, as a phase velocity modulator and for con-trolling the angle of emission of a light beam. The light valves may be light switches turning the modulated beam on or off or variable valves which permit the intensity of the modulated light beam to be varied continuously over a range by varying the intensity of the modulating light beam. In a valve the modulating light beam pumps the electrons into higher energy bands causing the critical angle for a light beam incident upon an interface to be increased for some frequency bands and decreased for other bands as the intensity of the pump or modulating light increases.
FIG. 1 illustrates one such device. It has a substrate 110 supporting a polyaniline mass 112 in the form of a film bonded to the substrate 110. The interface between the polyaniline film 112 and the air will have a critical angle of, for example, C1 when the modulating light 114 does not pump the polyaniline film 112 and a critical angle C2 when the pump light 114 is intense. The angles are greatly exaggerated for illustration. In this example when the modulating light 114 does not pump the polyaniline film 112, a light beam 116 which is incident upon the polyaniline film at an angle greater than the critical angle C1 will not be substantially transmitted into the film 112 but instead will be reflected along a path 118. However, when the modulating beam 114 is turned on for pumping, the critical angle increases to angle C2 thus permitting the coupling of light from the beam 116 into the film 112.
We have found that the critical angle is increased by an increase in the intensity of the modulating beam for some frequency ranges of incident modulated light and is decreased for others. Thus, the illustration of FIG. 10 continues to be accurate for all events. However, for some frequencies of incident, modulated beam, the critical angle when the polyaniline is not pumped is the greater angle and then decreases to C1 as pumping energy is increased.
The result is that the incident light beam is always substantially equal to the critical angle being either slightly greater or lesser than the precise critical angle depending upon the incident beam frequency. Thus, the structure can be used so that increasing the intensity of the pumping, modulating beam 114 will turn off the coupling of light from one transmission medium to another for some optical bands while turning on the coupling for other bands.
FIG. 2 illustrates a structure utilizing the same principles as illustrated in FIG. 10 but for coupling the light from the polyaniline film 120 into another light transmissive medium 122. However, in the structure of FIG. 11, the interface at which the critical angle is important is the interface between the polyaniline film 120 and the light conductor 122. Thus, in the embodiment of FIG. 11 the incident light beam 124 must be incident at an angle such that after it enters the polyaniline film and is refracted along a different path it will approach the interface between the polyaniline film 120 and the transmissive substrate 122 at substantially the critical angle, being greater or lesser than the critical angle by a smaller amount in accordance with the principles described in connection with FIG. 1. The coupling of light from the polyaniline layer of 120 to the other layer is thus controlled by the modulating light 126. From the above description it is apparent that a beam in the opposite direction may also be similarly controlled.
FIG. 3 illustrates another embodiment similar to the embodiment of FIGS. 1 and 2. In FIG. 3, however, an optical fiber light conductor 130 has a polyaniline layer 132 upon at least a portion of its outer longitudinal surface. In this manner a pumping light 134 can control the coupling of an incident light beam 136 into the optical fiber 130.
FIG. 4 illustrates an optical fiber 140 having an endface 142 which is lapped at substantially the critical angle for the interface between the optical fiber 140 and a polyaniline layer 144 coated on the lapped endface. An incident light beam 146 may be directed upon the polyaniline film 144 parallel to the longitudinal optical axis of the optical fiber 140. The device operates on the same principles described in connection with FIGS. 1 and 2 except the light beam when coupled into the optical fiber 140 enters along the longitudinal optical axis.
FIGS. 5 and 6 illustrate yet another device in which a pair of optical fibers 150 and 152 are controllably coupled together by an interposed polyaniline mass 154 joining the two fibers. Together these form three light conducting media. An input light beam 156 propagating along the fiber 150 enters the region along which the polyaniline 54 is distributed. The coupling of light into the polyaniline 154 and into the second optical fiber 152 is controlled by the pumping beam 158 so that some of the light from input light 156 is coupled into optical fiber 152 to provide as output light 159.
FIG. 7 illustrates a Mach Zehnder interferometer made up of light conductors in which input light 160 arrives in optical fiber 162 and is divided into two paths 164 and 166. These two paths are recombined at optical fiber 168. In accordance with the principles of the prior art Mach Zehnder interferometer, if the two beams arrive in phase in the output fiber 168 they constructively interfere and the light beam and any associated signal continues along the path. However, if the beams destructively interfere, the light beam is destroyed. By variably controlling or altering the phase velocity through the branch 166, the relative phases of the two light signals recombining at output optical fiber 168 may be controllably varied between constructive and destructive interference.
While the Mach Zehnder interferometer is old and known, we have found a new manner of controlling the phase velocity in the branch 166. The branch 166 is coated with a layer of the photo responsive polyaniline film 170. A variable intensity pumping light 172 for modulating the index of refraction of that layer is used to control the phase velocity of the light through the branch 166. Thus, varying the intensity of the modulating or pumping light 172 changes the phase velocity in the branch 166 and therefore changes the phase relationship between the two arriving signals in the output fiber 168.
The microwave devices of the present invention arise because we have discovered that a highly protonated emeraldine salt polymer has a high dielectric loss which we attribute to its combination of a modest conductivity and a high dielectric constant. The loss tangent, a quantitative indication of the energy loss in the polymer, is a function of the protonation level of the polymer and increase as the protonation level increases reaching a maximum at complete 50% protonation. Very importantly, the protonation level may be controlled as described above in the synthesizing of the material and also may be varied by changing the potential by means of an electrochemical cell. This permits the polymers to be made with a variety of selected loss tangents and further permits the loss tangents of the polymers to be variably controlled in a variety of useful devices. For example the microwave properties may be turned on and off or varied over a range.
In FIGS. 8 and 9 a layer 180 of protonated polyaniline is bonded to the interior walls of a wave guide 182. As the microwave propagates from the input end 183 to the output end 184, it is attenuated in the polyaniline layer. This layer may be formed with a continuously changing protonation level along the propagation axis of the waveguide to provide a selected protonation gradient and therefore loss gradient between the input end 183 and output end 184. This gradient can be contoured to minimize reflections where the propagating microwave encounters the transition from an absence of polyaniline layer to the presence of the layer. Additionally, the layer may be geometrically formed to gradually taper to a greater thickness as the microwave propagates from the input end 183 to the outlet end 184.
FIG. 10 illustrates a similar wave guide 186 having a mass of polyaniline 188 formed so that it has a geometrical configuration providing an increase in thickness, that is an increase in its cross sectional area in planes perpendicular to the axis of propagation.
FIG. 11 illustrates another embodiment of the invention in which the polyaniline mass is positioned within the interior of a waveguide 190 and also extends between its walls. In the interior of the embodiment of FIG. 11 there is positioned a plurality of laminated layers 192 of polyaniline each layer having a different protonation level. This structure is particularly suitable for terminating the end 194 of a waveguide 190 in a manner to prevent reflections. Other circuitry may be used to direct unwanted microwave energy, for example, into the illustrated wave guide where it can be effectively attenuated. In order to minimize reflections, as described above, the layers initially encountered by the incoming microwave are the least protonated so they are the less absorptive. The layers become increasingly more protonated and therefore more absorptive as they are positioned closer to the end 194 of the wave guide 190. Preferably, the average gradient of the variation in protonation and therefore in the variation in absorption is approximately a linear function of distance along the propagation axis.
Referring to FIG. 12, if it is desired to prevent reflections of microwave energy from a metallic or other reflective surface 196, the surface may be coated with a polyaniline layer 198 which is provided with a protonation gradient which increases from near 0% at the exposed outer surface 200 to a much greater level, 50% for example, at the interface 202 between the reflection surface 196 and the polyaniline layer 198.
Similarly, as illustrated in FIGS. 13, 14 and 15 the polyaniline absorptive layer may be bonded to the exterior surface of a microwave strip conductor such as conductor 206 in FIG. 13. This provides a convenient means for introducing attenuation onto a microwave strip conductor used in miniature or integrated circuits while minimizing reflections from it. For example, the polyaniline layer 208 may be synthesized as described above so that it has a variation in its protonation or pseudo-protonation as a function of its position or distance along the axis of propagation of the strip conductor. The protonation varies from a minimum protonation level at its opposite ends 210 and 212 increasing toward the central region to a maximum protonation at the central region to 214.
FIG. 14 illustrates use of the polyaniline as a terminating absorber on the end of a branch of the microwave strip conductor 220. The polyaniline layer 222 is formed with a protonation gradient extending from a minimum protonation at its input end 224 to a maximum protonation at its terminating end 226.
The gradual variation in the microwave loss tangent so that absorption increases gradually from the input end to the opposite end along the propagation axis may alternatively be accomplished or may be supplemented by increasing the thickness of the polyaniline layer to also increase energy absorption.
One major advantage of polyaniline materials used in the present invention is that their protonation and therefore their absorption or loss tangent may be controlled by an electrical potential. This feature may be utilized in many various embodiments of the invention but is illustrated in FIG. 15.
FIG. 15 illustrates a microwave strip conductor 230 upon which a polyaniline layer 232 is positioned of the type illustrated in FIG. 13. The strip may, if desired, have a protonation or a thickness gradient. This layer, because it is also conductive, may also serve as one electrode of an electrochemical cell. It is connected to a variable potential 234. The other terminal of the variable potential 234 is connected to the other electrode 236 of this electrochemical cell. A solid or liquid electrolyte 238 is positioned between the electrodes 232 and 236. Thus, the application of the variable potential 234 permits the potential of the polyaniline 232 to be varied, controlling or varying its protonation as a function of the potential and thereby varying its absorption or loss tangent. In this manner, the effect of the polyaniline layer 232 may be switched on and off by switching the polyaniline between fully protonated and unprotonated states and may be varied to intermediate levels of protonation.
FIG. 16 illustrates a structure for controlling and varying the protonation gradient along a microwave strip conductor 240 by forming the polyaniline layer into a series of discrete segments 241 and 242 along the axis of propagation of the microwaves. Each individual polyaniline segment forms an electrode of a separate electrochemical cell. Each of these cells has a second electrode 244 and 246, for example, and an interposed electrolyte like the electrolyte 238 in FIG. 25 but separately associated with each individual electrochemical cell. A separate potential is applied for controllably varying the potential of each discrete segment of polyaniline mass along the propagation axis so that its loss tangent may be independently varied. Different potentials may be applied to each of these discrete cells to controllably contour the protonation gradient which is desired for particular circumstances.
FIGS. 17 and 18 illustrate embodiments in which a thermally responsive film has microwave radiation absorbing protonated polyaniline salt polymer distributed in the thermally responsive film. The term distributed is intended to include the various chemical techniques for distributing the active materials in a thermally responsive film material, this includes dispersing and copolymerization. This distribution of the microwave radiation absorbing polymer in the thermally responsive film permits the film to be activated by microwave energy rather than by radiation with infrared energy. This is particularly useful in electrically insulative environments in which the energy may be coupled specifically into the thermally responsive film without undue heating of surrounding structure and from a remote source.
For example, if the principal carrier film is a thermally deformable film such as thermo-plastic film which softens and flows more easily when heated, it may be used to form a barrier or closure which can be destroyed from a remote position by irradiation with microwave energy. For example, FIG. 17 illustrates a conduit 250 having a thermoplastic film 252 with microwave radiation absorbing protonated polyaniline salt polymer distributed within it to form a barrier between the conduit 250 and a conduit 254. This sealing film will block passage of fluids, for example, past the barrier formed by the film 252 until the film is radiated by microwave energy 256 causing the barrier to be heated, softened and eventually separate to open the passage.
The microwave radiation absorbing protonated polyaniline salt polymer may also be distributed in or copolymerized with a conventional thermally activated shrink wrap film. For example, FIG. 18 illustrates a conduit 260 having a defect or crack 262. The film 264 is loosely wrapped around the conduit 260 and the film 264 is then irradiated with microwave energy 266 causing the polyaniline polymer to absorb the microwave energy convert it to heat thereby heating the film and activating its shrink properties.
The microwave absorptive polyaniline film can be advantageously used for shielding objects as mentioned above and is particularly useful for shielding a plurality of electrical conductors to form a shielded cable. The polyaniline shield not only prevents electromagnetic energy from entering the cable and thereby coupling noise into the conductors and prevents electromagnetic energy from exiting the cable but additionally because the polyaniline is also conductive, the outer conducting polyaniline shield may also be used to ground an electronic device to which it is connected. Thus, because the polyaniline is also conductive, it may not only absorb rather than merely reflect the microwave energy but it may also conduct current to maintain an electrical apparatus at a ground potential.
In order to measure the variation in loss of the polyaniline polymer as a function of protonation, we measured the loss tangent for five different samples spaced across the range between the emeraldine base at no prontonation and the emeraldine salt at full 50% protonation. FIG. 19 is a plot of the results of the data illustrating the loss tangent in the vertical axis as a function of percent of protonation on the horizontal axis. For each sample there is illustrated a data point as well as error bars indicating the estimated accuracy with which the measurements were made. This graph illustrates the increase in loss within the polymer as protonation is increased.
While the invention has been disclosed in this patent application by reference to the details of preferred embodiments and examples of the invention, it is to be understood that this disclosure is intended in an illustrative rather than in a limiting sense, as it is contemplated that modiciations will readily occur to those skilled in the art, within the spirit of the invention and the scope of the claims which follow.
|
A composition for absorbing electromagnetic radiation (such as microwave, infrared, visible light radiation ultraviolet radiation), wherein said electromagnetic radiation possesses a wavelength generally in the range of from about 1000 Angstroms to about 50 meters, wherein said composition comprises a polyaniline composition of the formula ##STR1## where y can be equal to or greater than zero and R' and R 2 are independently selected from the group consisting of --H, --OCH 3 , --CH 3 , --F, --Cl, --Br, --I, --NR 3 2 , --NHCOR 3 , --OH, --O, --SR 3 , --OR 3 , --OCOR 3 , --NO 2 , --COOH, --COOR 3 , --COR 3 , --CHO, and --CN, where R 3 is a C 1 to C a alkyl, aryl or aralkyl group.
| 3
|
TECHNICAL FIELD
[0001] The present invention generally relates to integrated circuit design and fabrication, and more particularly, to an antifuse structure and method for fabricating the same.
BACKGROUND OF THE INVENTION
[0002] Fuses and antifuses are common components in conventional integrated circuits. Fuses are commonly formed from a metal or polycide layer which is narrowed down in the region of the fuse. Fuses are then typically blown by applying a voltage or laser to heat the metal or polycide above a melting point, causing the fuse to open and the conductive link. In contrast, an antifuse is a circuit element that is normally open circuited until it is programmed, at which point the antifuse assumes a relatively low resistance. Conventional antifuses are similar in construction to capacitors in that they include a pair of conductive plates separated from each other by a dielectric or insulator. Antifuses are typically characterized by the nature of the dielectric which may be, for example, oxide or nitride. Antifuses are programmed or blown by applying a differential voltage between the plates that is sufficient to break down the dielectric thereby causing the plates to electrically contact each other.
[0003] Fuses and antifuses are used in a variety of applications. One such application is to selectively enable certain features of integrated circuits. For example, semiconductor devices are often designed to be operated in multiple modes of operation, with the specific mode of operation programmed after the fabrication of the device has been completed. One method for programming the device is through the use of a fuse or antifuse. More commonly, however, fuses and antifuses are used to perform repairs of integrated circuits, such as in redundancy technology. Repairs of integrated circuits are typically accomplished by blowing the appropriate fuses or antifuses to signal defective portions of the integrated circuit that they should be replaced with redundant circuits. For example, a defective row of memory cells in the array of a dynamic random access memory (DRAM) devices can be replaced with a redundant row of cells provided for that purpose. As demonstrated by this example, redundancy technology can be used to improve the fabrication yield of high-density memory devices, such as DRAM and static random access memory (SRAM) devices, by replacing failed memory cells with spare ones using redundant circuitry activated by programming the fuses or antifuses.
[0004] As previously discussed, antifuses are similar in structure to semiconductor capacitors. Consequently, the fabrication of antifuses can be easily integrated into conventional DRAM device fabrication processes, since, as well known in the art, DRAM devices rely on semiconductor capacitors to store data. However, in devices where capacitors are not typically formed, such as in SRAM devices, integrating the fabrication of antifuses into the conventional process flow is difficult. As a result, fuses are used typically used in SRAM devices rather than antifuses.
[0005] Although fuses have been used extensively in semiconductor devices, antifuses provide several advantages over their fuse counterparts. For example, one advantage with antifuses is the ease of programming while the device is on a tester, as opposed to fuses, where the wafers must be transferred to a laser trimmer. Not only does the laser trimming process add time to the entire process, the additional step introduces another point in the process at which catastrophic mistakes can occur. For example, wafers of a lot can be accidentally trimmed using the fuse trimming profile of another lot, or wafers can be rearranged within a lot such that the reordered wafers are trimmed using the incorrect fuse trimming profile. These types of errors typically result in scrapping the mistrimmed wafers.
[0006] Additionally, as the size of semiconductor devices decreases, using lasers to blow fuses has become more difficult. That is, as semiconductor devices decrease in size and the degree of integration increases, the critical dimensions, including fuse pitch, become smaller. The availability of lasers suitable to blow the fuse becomes limited since the diameter of the laser beam should not be smaller than the fuse pitch. Thus, the fuse pitch, and the size of semiconductor devices, becomes dictated by minimum diameter of laser beams obtainable by current laser technology.
[0007] Moreover, another disadvantage with employing fuses instead of antifuses is related to conventional fuse fabrication processes. As previously discussed, conventional fuse fabrication processes typically form fuses from a polycide layer, which is deposited early in the fabrication process of the device. That is, the polycide layer from which fuses are formed is covered by multiple layers that are formed later in the processing of the device. For semiconductor devices having multiple levels of metallization, such as in SRAM devices, it is becoming very difficult to etch down through the multiple layers of oxide between the levels of metallization to expose the polycide fuses. If the oxide is not sufficiently etched, the fuses may not be completely blown by the laser trimmer, which typically results in malfunction of the device.
[0008] Therefore, there is a need for an antifuse structure and method for forming the same that can be integrated into the fabrication processes for devices that typically do not include the formation of semiconductor capacitors.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to an antifuse including a bottom plate having a plurality of longitudinal members arranged substantially parallel to a first axis, a dielectric layer formed on the bottom plate, and a top plate having a plurality of longitudinal members arranged substantially parallel to a second axis, the top plate formed over the dielectric layer. The longitudinal members of the bottom plate and the top plate can be arranged orthogonally with respect to each other. The longitudinal members of the bottom plate can have at least one edge over which the dielectric material and the longitudinal members of the top plate are formed. The antifuse can further include a first interlayer, a first plurality of slots formed in the first interlayer in which the longitudinal members of the bottom plate are formed, a second interlayer formed over the first interlayer, and a second plurality of slots formed in the second interlayer in which the longitudinal members of the top plate are formed.
[0010] One aspect of the invention includes multiple edges at the interfaces between the top and bottom plates. Consequently, edges, such as the ones formed from the arrangement, result in regions of localized charge concentration when a programming voltage is applied across the antifuse. As a result, the formation of the antifuse dielectric over the corners of the bottom plates enhance the electric field during programming of the antifuse. Reduced programming voltages can be used in programming the antifuse. The resulting filament, that is, the conductive path, between the top and bottom plates will likely form along the multiple edges.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a simplified cross-sectional view of a semiconductor substrate that can be processed to form an antifuse in accordance with an embodiment of the present invention.
[0012] [0012]FIG. 2 is a simplified cross-sectional view of the substrate of FIG. 1 at a later point in processing, in accordance with an embodiment of the present invention.
[0013] [0013]FIG. 3 is a simplified cross-sectional view of the substrate of FIG. 2 at a later point in processing, in accordance with an embodiment of the present invention.
[0014] [0014]FIG. 4 is a simplified cross-sectional view of the substrate of FIG. 3 at a later point in processing, in accordance with an embodiment of the present invention.
[0015] [0015]FIG. 5 is a simplified cross-sectional view of the substrate of FIG. 4 at a later point in processing, in accordance with an embodiment of the present invention.
[0016] As is conventional in the field of integrated circuit representation, the lateral sizes and thicknesses of the various layers are not drawn to scale, and portions of the various layers may have been arbitrarily enlarged or reduced to improve drawing legibility.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Embodiments of the present invention are directed to an antifuse structure and method for forming the same that can be integrated into fabrication processes that include a damascene local interconnect and contact formation processes. In the discussion which follows, the invention is described with reference to an SRAM memory device. However, it should be understood that the invention pertains to any applications where formation of an antifuse is desired. Additionally, in the following detailed description, reference is made to various specific embodiments in which the invention may be practiced. These embodiments are described with sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be employed, and that structural and process changes may be made without departing from the teachings of the invention.
[0018] It will be appreciated that the terms “wafer” or “substrate” used in the following description may include any semiconductor-based structure that has an exposed silicon surface. Wafer and structure must be understood to include silicon-on insulator (SOI), silicon-on sapphire (SOS), doped and undoped semiconductors, epitaxial layers of silicon supported by a base semiconductor foundation, and other semiconductor structures. The semiconductor need not be silicon-based. The semiconductor could be silicon-germanium, germanium, or gallium arsenide. When reference is made to a wafer or substrate in the following description, previous process steps may have been utilized to form regions or junctions or layers in or on the base semiconductor or foundation.
[0019] [0019]FIG. 1 is a simplified cross-sectional view of an antifuse region 100 shown along side a portion of an SRAM memory cell 102 at a stage of processing on a substrate 104 . Although the antifuse region 100 and SRAM memory cell 102 are shown to be adjacent in FIG. 1, the antifuse region 100 is typically located outside of a memory array in which the SRAM memory cell 102 is located. The dashed line is provided to avoid any confusion over the relative location of the antifuse region 100 with respect to the SRAM memory cell 102 . The antifuse region 100 and SRAM memory cell 102 are shown in FIG. 1 in this manner to illustrate the process steps in forming antifuses according to embodiments of the present invention with relation to forming an exhumed contact and local interconnect of the SRAM memory cell 102 . A more detailed description of an antifuse will be provided with respect to FIGS. 2 through 5, which illustrate an antifuse and the SRAM memory cell 102 at various stages of processing.
[0020] As previously mentioned, the portion of the SRAM memory cell 102 that is shown in FIG. 1 is where an exhumed contact and local interconnect will be formed. The portion of the SRAM memory cell 102 shown in FIG. 1 includes first, second and third gate structures 110 , 114 , 118 formed on a doped well region 106 . The well region 106 is typically doped to a predetermined conductivity, for example, p-type or n-type, depending on whether NMOS or PMOS transistors will be formed therein. Formation of the well region 106 in the substrate 104 can be accomplished using well-known semiconductor processing techniques. The gate structure 110 is formed over a shallow trench isolation (STI) structure 112 . An STI structure 140 is also formed in the antifuse region 110 , on which an antifuse will be formed. Each of the gate structures 110 , 114 , 118 includes a gate oxide 120 , a gate layer 122 , a conductive layer 124 , and a dielectric cap 130 . The gate oxide 120 , the gate layer 122 , the conductive layer 124 , and the dielectric cap 130 can be formed using conventional processes and materials known by those of ordinary skill in the art. For example, the gate oxide 120 can be a silicon oxide material formed a thermal oxidation process, and the gate layer 122 can be formed from a doped polysilicon material deposited using conventional chemical vapor deposition (CVD) techniques, plasma-enhanced CVD (PECVD) techniques, or the like. The conductive layer 124 provides a relatively low resistance current path and can be formed from a tungsten or tungsten nitride material. Dielectric spacers 134 are formed along the sides to cover the gate oxide 120 , gate layer 122 , conductive layer 124 and dielectric cap 130 . A tetraethyl orthosilicate (TEOS) glass material can be used for the dielectric cap 130 and the dielectric spacers 134 . It will be appreciated that although specific materials and processes have been described in the present example, other suitable materials and fabrication processes can be used in forming the various layers of the gate structures 110 , 114 , 118 , as well.
[0021] The dielectric cap 130 of the gate structure 110 has been partially removed to expose a portion of the conductive layer 124 on which the exhumed contact will be formed. An etch stop layer 150 and an interlayer 152 are formed over the SRAM memory cell 102 and the antifuse region 100 . The etch stop layer 150 can be formed from a silicon nitride material and the interlayer 152 can be formed from a boron silicate glass (BSG), a borophosphorous silicate glass (BPSG), or similar material.
[0022] [0022]FIG. 2 is a simplified cross-sectional view of the antifuse region 100 and the SRAM memory cell 102 (FIG. 1) at a later stage of processing. FIG. 2 includes a top plan view of the antifuse region 100 . Although not shown in FIG. 2, the interlayer 152 is masked, and the interlayer 152 and the etch stop layer 150 are subsequently etched to form a exhume contact opening 160 exposing a portion of the well region 106 . In the antifuse region 100 , openings 164 are concurrently formed with the exhume contact opening 160 . It will be appreciated that the etch processes used to etch the interlayer 152 and the etch stop layer 150 are selective to the material of the dielectric cap 130 , dielectric spacers 134 , and the conductive layer 124 . Conventional photolithographic and etch processes can be used in the formation of the exhume contact opening 160 and the openings 164 , as is well known in the art.
[0023] [0023]FIG. 3 is a simplified cross-sectional view of the antifuse region 100 and the SRAM memory cell 102 (FIG. 2) at a later stage of processing. A conductive material is deposited over the interlayer 152 to fill the exhume contact opening 160 and the openings 164 , and subsequently etched to remove the conductive material from the surface of the interlayer 152 . As a result, a local interconnect 168 is formed in the exhume contact opening 160 and conductive plates 170 are formed in the openings 164 . The local interconnect 168 is in electrical contact with the exposed portion of the conductive layer 124 of the gate structure 110 . A second interlayer 172 is formed over the interlayer 152 , covering the local interconnect 168 and the conductive plates 170 . The second interlayer 172 can be formed from the same material from which the interlayer 152 is formed. The conductive material from which the local interconnect 168 and the conductive plates 170 are formed can be a conventional material, such as tungsten. However, it will be appreciated that other suitable materials may be used as well without departing from the scope of the present invention.
[0024] [0024]FIG. 4 is a simplified cross-sectional view of the antifuse region 100 and the SRAM memory cell 102 (FIG. 3) at a later stage of processing. The second interlayer 172 is masked and etched to form openings 174 and 176 over the local interconnect 168 and the antifuse region 100 , respectively. The openings 176 are etched generally perpendicular to the length of the conductive plates 170 to form a “crisscross” pattern. This is illustrated in the plan view included in FIG. 4. The openings 176 are etched to a depth of D below the top of the conductive plates 170 . The etch process used to form the openings 174 and 176 is selective to the material from which the local interconnect 168 and the conductive plates 170 are formed. In the present example, the etch process is selective to tungsten. The second interlayer 172 is then masked to cover the SRAM memory cell 102 while leaving the openings 176 exposed. An antifuse dielectric 178 is formed over the exposed surfaces of the openings 176 , including the exposed surfaces of the conductive plates 170 . The antifuse dielectric 178 can be formed from conventional dielectric materials, such as silicon oxide, silicon nitride, and the like. Moreover, although the present example employs a single layer dielectric, it may be desirable to employ a multi-layer antifuse dielectric instead. Fabrication of such a dielectric structure is well known in the art.
[0025] [0025]FIG. 5 is a simplified cross-sectional view of the antifuse region 100 and the SRAM memory cell 102 (FIG. 4) at a later stage of processing. A conductive material is deposited over the second interlayer 172 to fill the openings 174 and 176 , and subsequently etched to remove the conductive material from the surface of the second interlayer 172 . As a result, a conductive plug 180 is formed in the opening 174 , which can be used to electrically connect the local interconnect 168 to a later formed conductive interconnect (not shown). Second conductive plates 182 are also formed in the openings 176 over the antifuse dielectric 178 from the conductive material.
[0026] An antifuse 200 is formed from the orthogonally arranged conductive plates 170 and 182 , and the antifuse dielectric 178 . Although not shown in FIGS. 1 - 5 , the antifuse 200 is electrically coupled to a conventional antifuse programming circuit. As well known in the art, the antifuse programming circuit is used to program the antifuse 200 when desired. A conventional sensing circuit may also be electrically coupled to the anti fuse 200 as well where sensing the programmable state of the antifuse is desired. Such circuits are well known in the art, and will not be discussed in detail herein in order to avoid obscuring the present invention.
[0027] It will be appreciated that the arrangement of the antifuse 200 shown in FIG. 5 provides multiple edges at the interfaces between the first conductive plates 170 , the antifuse dielectric 178 , and the second conductive plates 182 . As well known in the art, edges, such as the ones formed from the arrangement of the present example, result in regions of localized charge concentration when a voltage is applied across the antifuse dielectric 178 . As a result, the orthogonal corner formation of the antifuse dielectric 178 with the first and second conductive plates 170 , 182 enhances the electric field during programming of the antifuse 200 . Consequently, reduced programming voltages can be used. The resulting filament, that is, the conductive path, between the first and second conductive plates 170 , 182 will consistently form along the edges.
[0028] The arrangement of embodiments of the present invention also provide the ability to adjust the magnitude of the programming voltage by designing the grid of the first and second conductive plates 170 , 182 with fewer or greater conductive crisscrossing plates. That is, the programming voltage for antifuses on a device can be tailored to the specific use, with some antifuses having a higher or lower programming voltage than other antifuses, if so desired. Moreover, fabrication of antifuses according to embodiments of the present invention can be easily integrated into with processes including a damascene local interconnect and contact formation processes, such as in the example of the SRAM memory cell 100 provided above.
[0029] From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. For example, the previously discussed embodiment includes arranging the first and second conductive plates 170 , 182 orthogonally with respect to one another. However, it will be appreciated that the arrangement of the first and second conductive plates 170 , 182 can be modified such that the orientation is other than perpendicular. Accordingly, the invention is not limited except as by the appended claims.
|
An antifuse including a bottom plate having a plurality of longitudinal members arranged substantially parallel to a first axis, a dielectric layer formed on the bottom plate, and a top plate having a plurality of longitudinal members arranged substantially parallel to a second axis, the top plate formed over the dielectric layer. Multiple edges formed at the interfaces between the top and bottom plates result in regions of localized charge concentration when a programming voltage is applied across the antifuse. As a result, the formation of the antifuse dielectric over the corners of the bottom plates enhance the electric field during programming of the antifuse. Reduced programming voltages can be used in programming the antifuse and the resulting conductive path between the top and bottom plates will likely form along the multiple edges.
| 7
|
BACKGROUND OF THE INVENTION
The world has become increasingly aware of the scarcity of fuel including, particularly, the fossil fuels, gas and oil. At the same time the world has become increasingly aware of the energy available from the sun, particularly, in those areas where there is a high percentage of days throughout the year when the sun is available for heating purposes and for other energy available in the sun's spectrum. For these reasons, a great deal of attention has been paid to the utilization of solar energy for heating systems and, particularly, for water heating systems.
In those instances wherein it is desired to use the hot water directly, the time interval between the collection of solar energy and its use in the form of hot water is relatively short. In the instances wherein the energy is intended to be used for space heating, as for example, heating of homes, the heating of hot water through the use of solar energy provides a storage means from which the heat can be later extracted for use in space heating.
Solar heating systems can be designed from the ground up so to speak, but frequently the system consists of applying a solar collector, or solar heating unit, to an already existing hot water tank. Typically, this is the case in home systems. Here the federal government regulations require that the solar heating unit be utilized in connection with an existing hot water heater which has its own heating source whether it be electric, gas or oil. Such systems include the solar collecting unit operating in association with a hot water heater or the solar heating unit operates in connection with a heat exchanger that is connected to the hot water heater. The heat exchanger may be a separate unit or it may be part of a larger water tank system. In any event, the liquid flowing through the solar collector which is usually mounted on a roof of a house, has water flowing through it that is heated in the process of being exposed to the sun's radiation. When the ambient temperature drops below freezing, the water circulating through the solar collector unit is apt to freeze and in so doing may burst the pipes in the solar collector. This would incapacitate the system and render substantial damage. Systems for preventing this are known to the art and usually involve the drainage of the solar collector unit, or the circulation therethrough of warm water from the hot water heater itself. Such known systems tend to be large and bulky, complicated and somewhat ineffective in operation. It goes virtually without saying that the possibility of freezing of a solar water heating system is an intolerable situation.
Accordingly, it is an object of the invention to provide an improved solar hot water heating system eliminating the objections of prior art devices.
It is a further object of the invention to provide a solar heating system of the nature indicated including an improved system for drainage of the circulating liquid through the solar collector unit when the ambient temperature drops below a predetermined value.
It is a further object of the invention to provide an improved heat exchanging unit which is small in size and efficient in operation for use in connection with a solar heating system including a solar collector and a water heater.
SUMMARY OF THE INVENTION
In carrying out the invention according to one form there is provided a solar water heating system comprising a water storage tank including cold water inlet means and hot water outlet means and comprising a water utilization system, a solar collecting unit having cold liquid inlet means and heated liquid outlet means and comprising a heating liquid system, an independent heat exchanger disposed between the water storage system and the heating liquid system, and means associated with the collector unit and the heat exchanger for draining the liquid from the solar collector and into the heat exchanger under certain predetermined temperature conditions. While the drainage mechanism may include a separate venting conduit, according to a preferred form of the invention, the venting conduit may be eliminated and the drainage achieved through appropriate selection of the dimensions of the conduit to and from the solar collector unit. It is a further object of the invention to provide an improved heat exchanger of the character indicated which is simple in construction, efficient in operation and easy to maintain.
It is a further object of the invention to provide an improved independent heat exchanger of the nature indicated which finds usefulness in association with already installed hot water systems.
Further advantages and objects of the invention will become apparent as the description proceeds.
In carrying out the invention according to a further form, there is provided pump means for pumping heating liquid from the independent heat exchanger to the liquid inlet means of the solar collecting unit and from the liquid outlet means of the solar collecting unit to the independent heat exchanger and including differential temperature sensing means for sensing the temperature differential between the heated liquid outlet means of the solar collecting unit and the entry to the independent heat exchanger from the water storage tank and for actuating the pump means upon a first value of the differential temperature and inactivating said pump means upon a second value of differential temperature less than the first value.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagramatic view of a solar water heating system according to the invention;
FIG. 2 is a sectional view on an enlarged scale of the heat exchanger unit forming part of the invention; and
FIG. 3 is a schematic drawing of a modified form of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, the invention is shown embodied in a system 10 (FIG. 1) which may comprise an ordinary home water heater 11, a solar collector unit 12 and an independent heat exchanger 13 connected together and controlled as will be more particularly described.
The water heater 11 may be of any ordinary well-known variety heated by electricity, gas, oil, or the like, to which cold water is supplied through an appropriate pipe 14 and from which hot water is taken by an appropriate pipe or conduit 15. The solar collector unit 12 may be of any well-known variety such, for example, as the units manufactured by the Colt, Inc. Cold water or other heating liquid is supplied through pipe or conduit 16 to the inlet 17 of the collector unit 12, and the heated water or other liquid is taken from the solar collector unit 12 through a pipe or conduit 18 at the heated liquid outlet 19, and is supplied to the inlet 21 of the separate, or independent, heat exchanger 13. Cooled heating liquid from the heat exchanger 13 flows out at outlet 22, and by means of the electrically operated pump 23 is supplied through pipe or conduit 16 to the input 17 of the solar collector unit. Circulation of heating fluid, which may be water, usually, takes place through suitable passages in the collector 12, these being shown diagramatically by the dotted lines 24.
Referring more particularly to FIG. 2, the heat exchanger 13 is shown as comprising an outer tank 25 insulated in any usual manner as by a layer of fiber glass insulation 26, an inner tank 27 suitably supported inside of the outer tank and a heat transfer coil 28 surrounding the inner tank 27 and having an inlet 29 and an outlet 31. The heat exchanger coil 28 may be, conveniently, in the form of a spiral and occupies a portion of the space 32 between the inner tank 27 and the outer tank 25. The inlet 29 of the spiral heat exchanger coil 28 communicates with the lower end of the hot water heater tank 11 as may be seen in FIG. 1, and the upper or outlet end of the spiral heating coil 31 is in communication with the conduit 15 which supplies hot water to the user from the hot water tank 11. The spiral heat exchanger coil 28 cooperates with the hot water tank 11 in the form of a thermal siphon in that when the water in the heat exchanger coil is heated it induces a circulation with the water inside of the hot water tank because heated water rises and the entry end 29 is at the lower end of the heat exchanger coil 28 and the lower end of the hot water heater 11.
The lower end of the inner tank 27 communicates with the outlet conduit 22 and at the upper end of the inner tank 27 there is a small pipe or conduit 33 extending through the inlet conduit 21 and terminating near the upper portion of the connecting fitting 34 as shown in FIG. 2. The fitting 34 communicates with the pipe or conduit 18 also connected to the outlet end of the solar collector 12. The fitting 34 may include an inspection, or cleaning, plug 35.
At the lower end of the inner tank 27 there are a series of openings 36 of which there may be, in the typical case, three disposed around the circumference of the tank.
During operation, heated water from the solar collector flows downwardly through conduit 18 and through the inlet 21 into the space 32 between the inner tank 27 and the outer tank 25. In so doing, the heated water comes into contact with the turns of the heater exchanger coil 28 causing the water therein to become heated and circulate into the hot water tank as already described. The heated water from the solar collector 12 and coming down through conduit 18 does not flow into the conduit 33 because the upper end thereof is disposed above the entrance of conduit 18 into the fixture 34 also as already described. The heat transfer fluid filling up the space 32 between the inner and outer tanks, however, flows through the openings 36 and into the interior of the inner tank 27. The heat transfer fluid, water for example, flows out of the inner tank 27 through the conduit 22. The pump 23 circulates the heating liquid from conduit 22 (the interior of inner tank 27) and through the conduit 16 to the solar collector inlet 17 as already described. The total area of the openings 36 is slightly larger than the inside diameter of the conduit 22 so that when the system is functioning and the pump 23 is operating, the liquid in the space 32 flowing through the openings 36 is adequate to supply the requirements of the pump 23. In this process the liquid inside of the inner tank 27 rises to a level shown approximately by the line 37.
When the system stops functioning, as for example when the temperature drops at night and in order to prevent freezing of the heating liquid (water) in the solar collector 12, the heating liquid in the solar collector drains back through conduit 16 and thus through pump 23 and conduit 22 into the interior of the tank 27. The liquid level under this condition rises about to that shown by the line 38. The space inside of the inner tank 27 is sufficiently large so that all of the heating liquid in the solar collector 17 can drain back into the interior of tank 27 and the space 32 between tank 27 and tank 25 so that no heating liquid (water) is in the solar collector and thus all danger of difficulty by freezing of the heating liquid is removed.
The drain back process under the conditions described does not give rise to the creation of a vacuum in the system which could prevent the drain out of the solar collector because the conduit 18 is made of somewhat greater inner diameter than that of the conduit 16. In this manner an air or other gaseous pathway is provided from the interior of the heat exchanger 13 to the solar collector. In a typical case the inside diameter of conduit 16 might be one-half inch and the inside diameter of conduit 18 might be three-quarters of an inch. Referring specifically to FIG. 2, it will be noted that the inside of the inner tank 27 which contains a gaseous medium such, for example, as air, communicates through conduit 33 with the upper portion of fixture 34. This provides communication between the interior of tank 27 and through conduit 33 and through the conduit 18 of increased diameter as compared with conduit 16 to the interior of the solar collector 12. Thus, there is an air pathway from the interior of tank 27 to the solar collector and no vacuum will form to prevent the drain back of liquid into the heat exchanger.
When the system is functioning and hot water is flowing downwardly through conduit 18 from the solar collector, the liquid level in the space 32 between the inner tank 27 and the outer tank 25 rises to the level shown approximately by the line 39. The level 39 is selected so that the hot water surrounds essentially all of the turns of the heat exchanger coil 28 and thus provides for maximum heating effect to the hot water tank 11. Other liquid levels may be chosen. The liquid level during operation can rise to the level 39 in the space 32 while the level inside of the tank 27 remains at the level 37 because the inside diameter of the conduit 22 may be slightly less than the total area of the openings 36. Thus, liquid can be pumped out through conduit 22 at a somewhat lesser rate as compared with what will flow into the interior of tank 27 through openings 36.
To turn the system on and off during appropriate temperature conditions, temperature sensors 41 and 42 are attached or associated, respectively, with the outlet 19 of the solar collector 12 and the cold water outlet 29 from the hot water heater 11. The temperature sensors 41 and 42 are connected, respectively, by means of conductors 43 and 44 to a differential controller 45, shown schematically, from which a conductor 46 extends to the motor of pump 23. The differential controller is connected by a conductor 47 to an ordinary wall plug 48 which may be plugged into a common ordinary house lighting circuit. The temperature sensors 41, 42, the differential controller 45 and the circuits connected thereto are standard available items from several sources and any may be utilized. One form is available from a company known as Heliotrope General and the components are sold under the name of "Delta T".
For ordinary operating conditions, when the temperature at sensor 41 reaches a level of about 15 degrees higher than the temperature at sensor 42, the pump 23 is caused to turn on. This causes heated water from the solar collector 12 to circulate through the system as described, thereby resulting in water in the hot water heater 11 being heated. During conditions of no sunlight such as at night or on cold overcast days or at any time when the weather is cold such that freezing of the water in the solar collector might take place, the temperature at sensor 41 reaching a level of only five degrees or so above the temperature level of sensor 42, the pump 23 is caused to turn off. Under this condition the water or heating fluid in the solar collector 12 drains back through conduit 16 by virtue of the mechanism and structure as already described. Thus, the solar collector becomes empty of heating water and no freezing can take place. Of course the water in the conduits 18 and 16 likewise drains down into the interior of the heat exchanger 13.
The heat exchanger 13 is of relatively small size and thus may be accommodated in the ordinary home water heating system without requiring the water heater itself to be replaced. Typically, the heat exchanger 13 may have a diameter of about ten inches and a height of about thirty-four inches excluding the thickness of the insulation surrounding it. Obviously, in the effort to conserve energy one or more inches of insulation would be provided around the exterior of the heat exchanger 13.
Other ways of breaking any vacuum that might exist in the lines during drain back of the water from the solar collector 12 may be used. Similarly, variations may be made in the heat exchanger 13. One form of modified structure is shown in FIG. 3 and will now be described. In FIG. 3 wherein the parts are essentially identical to those shown in FIGS. 1 and 2 the same reference characters will be used. Thus, in FIG. 3 there is shown a solar collector 12 and a heat exchanger 13.
The essential difference between the structures as illustrated in FIG. 3 and FIG. 1 is that a vacuum breaking conduit or pipe 18b is provided between the inlet of the heat exchanger 13 and the outlet 19 of solar collector 12. The conduit from the outlet 19 of the solar collector 12 namely, conduit 18a extending to the inlet of the heat exchanger 13 may be of the same diameter as the conduit 16 which supplies liquid to the solar collector 12 from pump 23. In this instance the diameter of conduit 18a may be of the same size as that of conduit 16. Not shown in FIG. 3 is the temperature sensing mechanism of FIG. 1, but it would be, in all respects, the same with the temperature sensors located at the corresponding points.
In the version shown in FIG. 3 when the system is functioning to provide heating water to the heat exchanger 13 the liquid level stands at the level shown by the line 37 and when the system has drained itself through the mechanism described, the level will stand at that shown by the line 39. To complete the air pathway so that any vacuum may be broken during the drain back, the inner tank 27 of FIG. 3 may be provided with a vent or opening 49 which communicates with the air space above the liquid level in the tank 25 and, thus, through the inlet 21 and fitting 34a to pipe or conduit 18b. Since there is an air supply available through pipe 18b to the outlet 19 of solar collector 12 there will be no vacuum formation therein and during the appropriate conditions, as described, the water in the solar collecter 12 and in the conduits 16 and 18a will drain back into the heat exchanger 13.
In either system, for the thermal syphon effect to function best, the heat exchanger 13 should be disposed at about the lower level of hot water heater 11. The cold water outlet from heater 11 to cold water inlet to heat exchanger 13, namely 29, conveniently are about at the same level. The principle that hot water rises should be taken advantage of in the thermal syphon effect between the hot water heater 11 and the heat exchanger 13.
While two forms of the invention have been shown it will be apparent that other forms may be made coming within the spirit and scope of the inventive concept.
|
In a solar water system including a solar collector prevention of damage to the collector during freezing conditions is achieved by providing a relatively small independent heat exchanger between the solar collector and the water heater and a vacuum breaking system whereby the water in the solar collector is drained into the heat exchanger. The heat exchanger is connected to a thermal siphon arrangement with the water heater.
| 5
|
BACKGROUND OF THE INVENTION
The present invention relates to a folding house designed in particular to be transported in the form of a stackable container.
Folding houses are known which have in the folded up position a width equal to or less than that of the road gauge and, in the unfolded or opened out position, a width about three times the preceding width, the reduction in the width for transport being achieved by the folding up, on each side of a central cell, of gable, outer wall, floor and roof panels.
The volume of these folded houses adapts them to transport, even on the road, but the height of these unfolded houses is at the most equal to the height of these houses when folded up.
Folding houses are also known which are similar to the preceding houses but equipped in their central part with an additional folding superstructure which is converted, when opened out, into a partly usable roof structure.
A drawback of the aforementioned houses is that their structure does not permit the stacking thereof.
Extensible transportable houses are also known which consist of a steel structure conforming to the dimensions and performances prescribed by the rules defining ISO containers.
They are extended by the outward translation of tridimensional shells which are integrated within the basic structure for transport.
Such houses are easily transportable and stackable but they have the drawback of a limited extension, since the width of the opened out house cannot exceed twice its width in the transport position and its height cannot exceed the height of the transported unit.
There exists an easily transportable and stackable house having the additional advantage of being equipped with autonomous loading and unloading means. Its structure is that of an ISO container and its handling devices are vertical telescopic racks placed close to the four corners of the container. As they are mounted on pivotable brackets, these racks are integrated for transport within cavities provided for this purpose in the sides of the container, and, in the position of use, they are opened out on each side of the container by pivoting on vertical axes of the brackets.
However, this house has the following drawbacks:
it is not extensible and any possible extensibility would be both limited and rendered more complicated by the presence of the rack cavities;
its handling devices consequently represent heavy equipment for a limited useful volume.
In contrast to the houses described hereinbefore, a house according to the present convention has the following advantages:
it has in the opened out position a height and a width, and consequently also a volume, which are greater:
in the folded up position, it forms a rigid, homogeneous container whose dimensions, characteristics and performances may be in conformity with the requirements of the ISO standards defining containers, and in particular the standards No. 668 and No. 1161, with all the resulting advantages for handling and transport.
SUMMARY OF THE INVENTION
For this purpose, according to a feature of the invention, the structure of the house comprises an axial bay constructed in the form of a ladder-girder which, without constituting an obstacle to interior circulation, imparts thereto stability and bracing while ensuring that the container formed by the house in the folded up position has a longitudinal bending strength allowing its handling and even its transport merely by its ends. Also, owing to such a girder no bending stress will oppose the folding of the longitudinal panels.
According to another feature this ladder-girder receives all the technical equipment which, bearing in mind all the imposed requirements, groups it advantageously in a well-structured zone.
According to a further feature of the invention, the median part of the roof structure is connected to posts mounted to pivot about horizontal pivots on said ladder-girder so that, while they are disposed horizontally in the transport position, they are disposed almost vertically when the house is opened out and thus raise the ridge of the roof well above the height of the container.
According to another feature of the invention, the house is provided, for reasons of autonomy, with its own devices for unloading from the transporting truck, and, owing it a particular arrangement of these devices, they can be used for the opening out of the house.
According to this arrangement, the unloading devices are located at the end of the container and are pivotable through 180° about a horizontal axis which permits, not only easily causing them to leave the gauge of the container in plan for effecting the unloading operations, but also giving them all the intermediate positions between the transport position and the unloading position for participating in the operations for unfolding the house.
Unloading devices are also known which are located on the sides of the container and mounted to pivot about a vertical axis so that it is possible to withdraw them into housings provided for this purpose so as to avoid reducing the section of the container throughout its length.
Apart from the drawback of these housings as concerns the interior geometry of the container, these devices can only move horizontally and therefore cannot take up positions required for opening out a house.
According to another feature of the invention, the strongest panels are used for forming the outer case of the container so as to protect the folded up house in the course of transport and, as it concerns floors, the final appearance of the unfolded house will not be affected by the usual unavoidable shocks and blows since the outer side of the panels during transport is no longer seen after the house has been opened out.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of a house according to the invention will appear from the following description with reference to an embodiment which is given merely by way of a non-limiting example. In the drawings:
FIG. 1 is a side elevational view of a house according to the invention in its folded up position.
FIG. 2 is a view in the direction II--II of FIG. 1
FIG. 3 is a view in the direction III--III of FIG. 1 to an enlarged scale.
FIG. 4 is a view similar to FIG. 3, the house being in the course of unloading from its transporting means.
FIG. 5 is a cross-sectional view of the same house in its folded up position.
FIG. 6 is an end elevational view of the same house in the course of opening out the house.
FIGS. 7, 8, 9 and 10 are diagrammatic sectional views of the same house at different stages of opening out.
FIG. 11 is a sectional view of the same house in the opened out position.
FIG. 11a shows a detail of FIG. 11.
FIG. 12 is an end elevational view of the house after the gable has been mounted.
FIG. 13 is a plan view of the house.
FIG. 14 is a side elevational view of one side of the house.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1, 2 and 4 show a container 1 constituted by a house according to the invention which has been folded up to permit its transport.
This container comprises, in its axial part, a ladder-girder 7 which terminates at each end in an end element 2 in the form of a tubular frame carrying the four standard corner blocks 3 of containers conforming to the ISO standard No. 1161.
Each upright of the end elements 2 carries a telescopic rack 6 through an arm 5 pivotally mounted thereon at 4, whereby each rack 6 is movable between the position it occupies in FIG. 3 and that which it occupies in FIG. 4.
In FIG. 3, the racks 6 are within the container and their lower part abuts under the effect of gravity against the sole plate constituting the floor of the container.
In FIG. 4, they have effected a rotation through 180° about the axis 4 and they are now located outside the gauge of the container in plan. Stop blocks 8 which abut against the sides of the floor of the container maintain them in this position.
Under these conditions, the container-house is unloaded in the following manner.
With the truck transporting the container in a position in which the container is vertically above the place it must occupy on the ground, the four racks 6 are pivoted about the pivots 4 until they are located outside the gauge. Their telescopic rods 65 are provided with plates 9 and they are lowered not only until the plates 9 touch the ground, but also to raise the container 1 with respect to the carrying platform of the truck which can therefore be withdrawn.
In order to obtain the final placing and support of the container, the lower blocks 3 are provided with plates 10 and the container 1 is lowered by means of the racks 6 whose telescopic rods 65 are retracted until the plates 10 bear against the ground. The plates 9 are retracted still further until they may be withdrawn.
The operations for opening out the house may now commence.
In order to explain these operations, FIG. 5 shows, after removal of end panels installed for the transport, all the elements which must be unfolded or opened out and the relationship therebetween. However, in order to render the drawing more clear, the technical equipment concerning the electricity, heating, airconditioning and sanitary equipment has not been shown in the median bay.
The ladder-girder 7 is of tubular construction except for the floor part where the cross-members are open section members so dimensioned as to permit the drillings required for the technical equipment and in particular the waste water pipes.
The floor of the house is formed by a fixed median part 11 and two lateral parts 12 and 13 pivotally connected at 14 and 15 to the median part.
The lateral part 12 of the floor carries, on one hand, a pivot 18 on which is pivotally mounted a corbelling panel 16 and, on the other hand, a pivot 20 on which is pivotally mounted the end of a structure 22 made from parallel posts spaced apart along the length of the house.
Likewise, the lateral part 13 of the floor carries, on one hand, a pivot 19 on which is pivotally mounted a corbelling panel 17 and, on the other hand, a pivot 21 on which is pivotally mounted the end of a structure 23 made from parallel posts spaced apart along the length of the house.
On some of the posts of the structures 22 and 23 there are vertically pivoted the panels which will close the interior rooms above the corbelling parts in continuation of transverse partitions, and the two panels located on each side of the entrance door when the latter is placed in one of the side walls of the house.
For purpose of transport, these panels, which are not seen in FIG. 5, are disposed between the posts within the thickness of the structures 22 and 23.
They will appear in FIG. 13 in the opened out position.
The other end of the structure 22 carries a pivot 24 on which is pivotally mounted, on one hand, an outer wall 26 and, on the other hand, a roof element 28, both of which are provided on their edges with semi-section members 30.
Likewise, the other end of the structure 23 carries a pivot 25 on which are pivotally mounted, on one hand, an outer wall 27 and, on the other hand, a roof element 29, both of which are also provided on their edges with semi-section members 30.
Further, the ladder-girder carries two pivots 31 and 32 on its edges.
Pivotally mounted on the pivot 31 are the posts 33 which carry at their end a roof element 35 through gussets 37.
Likewise, pivotally mounted on the pivot 32 are posts 34 which carry at their end a roof element 36 through gussets 38.
The roof element 35 carries struts 55 which are pivotable about horizontal axes, while the roof element 36 carries struts 56 also pivotable about horizontal axes.
On each side and at the end of the ladder-girder 7 two elements 39 and 40 constitute the two folded gables of the house.
The element 39 comprises a main panel 41 a part of which is mounted on a vertical pin (not shown). On this panel 41, an upper panel 43 is mounted on a horizontal pivot 47 and a lower panel 45 is mounted on a second horizontal pivot 49.
Likewise, the element 40 comprises a main panel 42 a part of which is mounted on a vertical pin (not shown). On this panel 42, an upper panel 44 is mounted on a horizontal pivot 48 and a lower panel 46 is mounted on a second horizontal pivot 50.
The opening out of the house will now be described with reference to FIGS. 6, 7, 8, 9 and 10.
Before lowering the sides of the container (FIG. 6), so as to give them the position they must occupy as parts of the floor of the living quarters, the bearing plates 54 are placed in the cavities 53 provided for this purpose (51), and then a hoisting pulley 51, which may be rigged with pulley-blocks if desired, is provided on each of the upper two corner blocks 3 located adjacent to the side it is desired to shift and a cable 52 is passed around each of the these pulleys and is hooked in any known manner, for example, to hooks placed in the upper part of said side.
With the cables 52 hardly taut, the side of the container is first of all pivoted outwardly and, as soon as the centre of gravity of the pivoted elements becomes vertically above the pivot 14 or 15, it is sufficient to retain this side until the plates 54 reach the ground.
The operation is repeated on the other side for lowering the other side of the container.
It will be noted that the floor of the opened out house then occupies on the ground an area equivalent to at least two and a half times the area occupied by the container.
When the floor has been fully laid out flat, the elements 35 and 36 constituting the median part of the roof are placed in position.
For this purpose (FIG. 7), the pulleys 51 of the upper raising blocks 3 are withdrawn and the telescopic rods 65 of the racks 6 are provided with these pulleys in their upper part. These rods are then raised to the maximum since they will act as raising masts, so that the pulleys 51 are as high as possible.
A cable 52 is then passed out each pulley and the roof elements 35 and 36 are hooked to these cables for the purpose of raising them.
It will be understood that in the course of this raising the roof elements 35 turns about the pivot 31 and the roof element 36 turns about the pivot 32, which move the posts 33 and 34 from the horizontal position they occupied in the container to a roughly vertical position, which raises the upper edge of the roof and therefore raises the ridge of the unfolded house relative to the height of the container.
Owing to this raising of the roof which is added to the opening out of the floor, the opened out house has a volume which becomes more than three times its volume in the "container" position.
During the raising of the roof, the struts 55 and 56 mounted on the roof elements 35 and 36 by horizontal pivots, remain substantially vertical and, at the end of the travel, their lower ends are made to bear on the edges of the ladder-girder 7 and they are fixed thereto by any means which are not part of the invention.
As the median part of the roof is immoblized, it is necessary to proceed to the first stage of the positioning of the gables 39 and 40. In the container, they are disposed parallel to the sides of the latter and must be put on the exterior of the house in a position perpendicular to their position of transport. This is achieved by rotating the whole of each gable about the vertical pivot on which it is mounted.
In FIGS. 5, 6 and 7, the gables 39 and 40 are in the transport position and the upper panels 43 and 44 and the lower panels 45 and 46 are folded onto the panels 41 and 42.
In FIGS. 8, 9 and 10, they have been disposed in the gable position but still with the upper and lower panels folded up as shown by dotted lines in FIG. 8.
The following stage of the opening out will be to place the roof elements 28 and 29 in position. But before explaining the various stages, it will be recalled that each of these elements is part of a unit.
The roof element 28 and the outer wall 26 are pivotally mounted at 24 on one end of structure 22 which is pivotally mounted at 20, at its other end, on the floor panel 12.
Likewise, the roof element 29 and the outer wall 27 are pivotally mounted at 25 on one end of the structure 23 which has its other end pivotally mounted at 21 on the floor panel 13.
For the moment, each of these units is flat on its floor panel and the first operation for opening out the roof elements 28 and 29 must be to bring these units to a vertical position.
For this purpose, after having pivoted the panels 16 and 17 down to the ground so as to avoid hindering the operation of the pivots 20 and 21, there are used as inclined raising masts the telescopic rods 65 of the racks 6 provided with their pulleys 51 (FIG. 8).
When the units 28, 26, 22 and 29, 27, 23 have been brought to the vertical position, they are locked by means which are not described since they are no part of the invention.
In the course of the raising of these units, there will be observed one of the functions of the semi-section members 30 with which the roof ends 28 and 29 and the front walls 26 and 27 are provided, on the edges. The opposition they exert through the web results in their acting as a beam which, in the course of the raising movement, opposes sufficient inertia to the bending stresses occurring in the course of this movement, so that it is possible to raise them by the ends.
Two other functions of these semi-section members will be seen hereinafter.
After locking the units 28, 26, 22 and 29, 27, 23 in the vertical position, the roof elements 28 and 29 (FIG. 9) are raised until their edge rabbets fit with the edge rabbets of the roof elements 35 and 36 and then they are interconnected. The overlapping of the elements 28 and 29 by the elements 35 and 36 produces a tile effect ensuring the running of rain water.
The following stage will comprise placing the outer walls 26 and 27 in position, these walls being at present in a vertical position against the structures 22 and 23 and must be brought to an inclined position (FIG. 10).
Indeed, on one hand, in order to have at least partial daily sunshine in each of the rooms of the house, irrespective of the orientation of the house and, on the other hand, in order to increase the interior volume, the outer walls 26 and 27 are inclined at about 30° to the vertical.
The outer walls are therefore raised and maintained in the raised position while the corbelling panels 16 and 17 are also raised--bearing in mind their weight this can be done easily by hand--these panels being then keyed to the outer walls by means which are not described since they are not part of the invention.
When one of the outer walls includes, as shown in FIG. 13, a door which must of course remain vertical while the window glazing must be inclined at 30°, it is constructed in the same way as the corbelling panel in two parts located on each side of the door. But the handling of each front wall element and each corresponding corbelling element is the same as for door-less front walls.
FIG. 11 illustrates the two functions of the semisection members 30 when the outer walls 26 and 27 and the roof elements 28 and 29 are in position in the opened out house.
On one hand, as they are mounted by a side, they form even in this position a beam which, in opposing the bending of the pivots 24 and 25, makes it possible to reduce the size of the structures 22 and 23 which carry these pivots.
On the other hand, they provide a seal at the junction between the outer walls and the roof, not only owing to the overlapping of the lower semi-section member by the upper semi-section member, but also owing to the fact that the upper semi-section member constitutes with a trough of the roof a true gutter, the overlapping and the gutter ensuring the running of rainwater out of the pivots 24 and 25.
After the front walls and the corbellings have been placed in position, the opening out of the exterior of the house is terminated by opening out of the gables. For this purpose, it is sufficient to raise the panels 43 and 44 (FIG. 12) and make them pivot about the pivots 47 and 48 and lower the panels 44 and 46 by making them pivot about the pivots 49 and 50.
It will be seen that, in the opened out position, the panels 43 and 44 will leave the median upper part open on each gable. In order to completely close the gables, ridge panels 61 are provided which are not an integral part of the house but which are nonetheless transported with the latter folded up in the space left free by the technical equipment in the median bay.
FIG. 13 is a plan view of a house according to the invention constituting a container having a standard length of 12,192 mm and a width of 2,438 mm, the plan view being taken not on the floor level but on the base of the outer wall window glazing at the level of two horizontal shelves surmounting the corbellings.
This plan view shows that the presence of the corbellings markedly increases the interior area of the house which is, in the presently-described embodiment, about 95 m 2 at the level of the plan view as compared with a house whose outer walls would be in alignment with the structures 22 and 23 which would provide an interior area of about 75 m 2 .
The entrance door is a pivoting door with an offset pivot axis. Its frame is formed by two posts of the structure 22 on which are pivotally mounted the two entrance sides closing the house above the corbelling panels and which, as mentioned before, were placed in the thickness of the structure 2 during transport of the folded up house.
Further, there can be seen the panels 63 and 64 which are provided for closing the interior rooms above the corbelling panels in continuation of the transverse partitions 59 and 60 and which were located for transport in the position shown in dotted lines, i.e. within the thickness of the structures 23 and 22.
This view shows that the sanitary equipment unit is installed in the median bay, i.e. within the ladder-girder 7. However, note the bath which exceeds the width of the latter. It concerns a bath capable of being swung up which was transported in the on-end position in the ladder-girder.
Because it was requested to provide a direct entrance into the living room and a reduction in the area of the kitchen, the sink and the cooking equipment of the kitchen were installed in the neighbouring bay of the ladder-girder 7. Both for transport, the sink and the cooking equipment, in one piece with their vertical partition placed behind, were disposed in the median bay on castors for the purpose of bringing them to their final position.
It must be understood that it is possible, without departing from the scope of the invention, to modify details of construction, their equipment or their arrangement so as to form equivalent modifications.
For example, in the case where there would be no entrance door in the outer wall, it would be possible to increase the inertia of the outer edge beams of the lateral floors so as to possibly eliminate the central plates 54 and/or shift the other plates 54 to the end of the panels so as to simplify the preparation of the supports.
For example, also the window glazing of the outer walls may be mobile in respect of some of them while the others are fixed, each mobile window glazing being capable of opening in two positions, namely partly open for low ventilation and fully open by a sliding thereof.
Exterior venetian blinds having orientable and retractable metal slats may provide protection against the sun and retractable inner blinds, for example made from a foam-fabric sandwich structure, may ensure isothermal conditions at night.
It is also possible, for example for hot countries which have a lot of sun, to reduce the window glazing and replace them by solid panels and/or provide continuous pentices.
Other possible modifications are: the uprights of the end elements 2 are equipped with bows for receiving a marquee for protecting the axial entrance or a garage may be attached as shown in FIG. 14.
In the chosen example, the framework of the garage comprises three longitudinal bars carrying rigid arches covered with a fabric. One of the bars is connected to bows, a second bar is connected to the end element 2 and the third bar is free. The ridge of the roof may be provided with aeration means which may or may not be movable and/or localized windows for zenith lighting.
On the other hand, it is also possible to close the gaps between the struts 55 and 56 with solid panels.
There may also be provided furniture specially adapted for a folding house, for example having several positions, namely for a table: a normal upper position, a semi-folded lower position and a folded up position for transport. Such furniture could be transported in the folded up house inside the ladder-girder or even on each side of the latter.
As concerns the loading, unloading, opening out and folding up operations, they could be assisted mechanically with possibly an electric power supply from the battery of the transporting truck with the motor running.
|
In this house, at least some of its component parts in the opened out position constitute, when the house is in the folded up position, a stackable container which is closed, compact and homogeneous throughout its length, within which container are disposed, folded up, all the other elements of the house, and in particular means a ladder-grider ensuring the stability and the bracing of the unfolded house and the longitudinal bending strength of the container formed by the folded up house.
| 4
|
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/052,919, filed May 13, 2008, and U.S. patent application Ser. No. 11/875,584, filed Oct. 19, 2007, the entire contents of which are specifically incorporated herein by reference.
BACKGROUND
[0002] Well completion and control are the most important aspects of hydrocarbon recovery short of finding hydrocarbon reservoirs to begin with. A host of problems are associated with both wellbore completion and control. Many solutions have been offered and used over the many years of hydrocarbon production and use. While clearly such technology has been effective, allowing the world to advance based upon hydrocarbon energy reserves, new systems and methods are always welcome to reduce costs or improve recovery or both.
SUMMARY
[0003] A drill-in liner assembly including a tubular and a plurality of substantially radially oriented openings in the tubular arranged in a pattern; the pattern selected to substantially maintain torsional strength of the tubular while facilitating in-flow of target fluid. Also including a plurality of beaded matrix plugs disposed within one or more of the plurality of openings such that torsional load placed upon the plurality of openings in the tubular is borne by the plugs.
[0004] An erosion resistant filtering arrangement including a tubular, a plurality of openings in the tubular arranged in a pattern, and a plurality of beaded matrix plugs disposed within one or more of the plurality of openings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Referring now to the drawings wherein like elements are numbered alike in the several Figures:
[0006] FIG. 1 is a perspective sectional view of a plug as disclosed herein;
[0007] FIG. 1A is a side view of a tubular with a diamond pattern of openings;
[0008] FIG. 2 is a schematic sectional illustration of a tubular member having a plurality of the plugs of FIG. 1 installed therein;
[0009] FIGS. 3A-3D are sequential views of a device having a hardenable and underminable substance therein to hold differential pressure and illustrating the undermining of the material;
[0010] FIG. 4 is a schematic view of a tubular with a plurality of devices disposed therein and flow lines indicating the movement of a fluid such as cement filling an annular space;
[0011] FIG. 5 is a schematic sectional view of a tubular with a plurality of devices disposed therein and a sand screen disposed therearound; and
[0012] FIG. 6 is a schematic view of an expandable configuration having flow ports and a beaded matrix.
DETAILED DESCRIPTION
[0013] Referring to FIG. 1 , a beaded matrix plug flow control device 10 includes a plug housing 12 and a permeable material (sometimes referred to as beaded matrix) 14 disposed therein. The housing 12 includes in one embodiment a thread 16 disposed at an outside surface of the housing 12 , but it is to be understood that any configuration providing securement to another member including welding is contemplated. In addition, some embodiments will include metal to metal sealing, elastomeric sealing arrangement such as an o-ring or similar sealing structure 18 about the housing 12 to engage a separate structure such as a tubular structure 19 with which the device 10 is intended to be engaged. In one embodiment the tubular has openings 21 each receptive to a device 10 , where the openings are configured in a pattern that is selected to maintain torsional rigidity of the tubular so that the tubular is still capable of being drilled in. One example of such a pattern is a diamond pattern with openings 21 equally spaced about a perimeter of the tubular in a first row and the same number of openings spaced evenly about the perimeter of the tubular in a second row but rotated to offset the openings from those of the first row (see FIG. 1A ). This patterned concept is continued over a selected length of the tubular to produce a diamond pattern when viewing the tubular from the side.
[0014] In the FIG. 1 embodiment, a bore disposed longitudinally through the device is of more than one diameter (or dimension if not cylindrical). This creates a shoulder 20 within the inside surface of the device 10 . While it is not necessarily required to provide the shoulder 20 , it can be useful in applications where the device is rendered temporarily impermeable and might experience differential pressure thereacross. Impermeability of matrix 14 and differential pressure capability of the devices is discussed more fully later in this disclosure.
[0015] The matrix itself is described as “beaded” since the individual “beads” 30 are rounded though not necessarily spherical. A rounded geometry is useful primarily in avoiding clogging of the matrix 14 since there are few edges upon which debris can gain purchase.
[0016] The beads 30 themselves can be formed of many materials such as ceramic, glass, metal, etc. without departing from the scope of the disclosure. Each of the materials indicated as examples, and others, has its own properties with respect to resistance to conditions in the downhole environment such as temperature, pressure erosional forces, etc. and so may be selected to support the purposes to which the devices 10 will be put. The beads 30 may then be joined together (such as by sintering, for example) to form a mass (the matrix 14 ) such that interstitial spaces are formed therebetween providing the permeability thereof. In some embodiments, the beads will be coated with another material for various chemical and/or mechanical resistance reasons. One embodiment utilizes nickel as a coating material for excellent wear/erosion resistance and avoidance of clogging of the matrix 14 . Further, permeability of the matrix tends to be substantially better than a gravel or sand pack and therefore pressure drop across the matrix 14 is less than the mentioned constructions. In another embodiment, the beads are coated with a highly hydrophobic coating that works to exclude water in fluids passing through the device 10 .
[0017] In addition to coatings or treatments that provide activity related to fluids flowing through the matrix 14 , other materials may be applied to the matrix 14 to render the same temporarily (or permanently if desired) impermeable.
[0018] Each or any number of the devices 10 can easily be modified to be temporarily (or permanently) impermeable by injecting a hardenable (or other property causing impermeability) substance 26 such as a bio-polymer into the interstices of the beaded matrix 14 (see FIG. 3 for a representation of devices 10 having a hardenable substance therein). Determination of the material to be used is related to temperature and length of time for undermining (dissolving, disintegrating, fluidizing, subliming, etc) of the material desired. For example, Polyethylene Oxide (PEO) is appropriate for temperatures up to about 200 degrees Fahrenheit, Polywax for temperatures up to about 180 degrees Fahrenheit; PEO/Polyvinyl Alcohol (PVA) for temperatures up to about 250 degrees Fahrenheit; Polylactic Acid (PLA) for temperatures above 250 degrees Fahrenheit; among others. These can be dissolved using acids such as Sulfamic Acid, Glucono delta lactone, Polyglycolic Acid, or simply by exposure to the downhole environment for a selected period, for example. In one embodiment, Polyvinyl Chloride (PVC) is rendered molten or at least relatively soft and injected into the interstices of the beaded matrix and allowed to cool. This can be accomplished at a manufacturing location or at another controlled location such as on the rig. It is also possible to treat the devices in the downhole environment by pumping the hardenable material into the devices in situ. This can be done selectively or collectively of the devices 10 and depending upon the material selected to reside in the interstices of the devices; it can be rendered soft enough to be pumped directly from the surface or other remote location or can be supplied via a tool run to the vicinity of the devices and having the capability of heating the material adjacent the devices. In either case, the material is then applied to the devices. In such condition, the device 10 will hold a substantial pressure differential that may exceed 10,000 PSI.
[0019] The PVC, PEO, PVA, etc. can then be removed from the matrix 14 by application of an appropriate acid or over time as selected. As the hardenable material is undermined, target fluids begin to flow through the devices 10 into a tubular 40 in which the devices 10 are mounted. Treating of the hardenable substance may be general or selective. Selective treatment is by, for example, spot treating, which is a process known to the industry and does not require specific disclosure with respect to how it is accomplished.
[0020] In a completion operation, the temporary plugging of the devices can be useful to allow for the density of the string to be reduced thereby allowing the string to “float” into a highly deviated or horizontal borehole. This is because a lower density fluid (gas or liquid) than borehole fluid may be used to fill the interior of the string and will not leak out due to the hardenable material in the devices. Upon conclusion of completion activities, the hardenable material may be removed from the devices to facilitate production through the completion string.
[0021] Another operational feature of temporarily rendering impermeable the devices 10 is to enable the use of pressure actuated processes or devices within the string. Clearly, this cannot be accomplished in a tubular with holes in it. Due to the pressure holding capability of the devices 10 with the hardenable material therein, pressure actuations are available to the operator. One of the features of the devices 10 that assists in pressure containment is the shoulder 20 mentioned above. The shoulder 20 provides a physical support for the matrix 14 that reduces the possibility that the matrix itself could be pushed out of the tubular in which the device 10 resides.
[0022] In some embodiments, this can eliminate the use of sliding sleeves. In addition, the housing 12 of the devices 10 can be configured with mini ball seats so that mini balls pumped into the wellbore will seat in the devices 10 and plug them for various purposes.
[0023] As has been implied above and will have been understood by one of ordinary skill in the art, each device 10 is a unit that can be utilized with a number of other such units having the same permeability or different permeabilities to tailor inflow capability of the tubular 40 , which will be a part of a string (not shown) leading to a remote location such as a surface location. By selecting a pattern of devices 10 and a permeability of individual devices 10 , flow of fluid either into (target hydrocarbons) or out of (steam injection, etc.) the tubular can be controlled to improve results thereof Moreover, with appropriate selection of a device 10 pattern a substantial retention of collapse, burst and torsional strength of the tubular 40 is retained. Such is so much the case that the tubular 40 can be itself used to drill into the formation and avoid the need for an after run completion string.
[0024] In another utility, referring to FIG. 4 , the devices 10 are usable as a tell tale for the selective installation of fluid media such as, for example, cement. In the illustration, a casing 60 having a liner hanger 62 disposed therein supports a liner 64 . The liner 64 includes a cement sleeve 66 and a number of devices 10 (two shown). Within the liner 64 is disposed a workstring 68 that is capable of supplying cement to an annulus of the liner 64 through the cement sleeve 66 . In this case, the devices 10 are configured to allow passage of mud through the matrix 14 to an annular space 70 between the liner 64 and the workstring 68 while excluding passage of cement. This is accomplished by either tailoring the matrix 14 of the specific devices 10 to exclude the cement or by tailoring the devices 10 to facilitate bridging or particulate matter added to the cement. In either case, since the mud will pass through the devices 10 and the cement will not, a pressure rise is seen at the surface when the cement reaches the devices 10 whereby the operator is alerted to the fact that the cement has now reached its destination and the operation is complete. In an alternate configuration, the devices 10 may be selected so as to pass cement from inside to outside the tubular in some locations while not admitting cement to pass in either direction at other locations. This is accomplished by manufacturing the beaded matrix 14 to possess interstices that are large enough for passage of the cement where it is desired that cement passes the devices and too small to allow passage of the solid content of the cement at other locations. Clearly, the grain size of a particular type of cement is known. Thus if one creates a matrix 14 having an interstitial space that is smaller than the grain size, the cement will not pass but will rather be stopped against the matrix 14 causing a pressure rise.
[0025] In another embodiment, the devices 10 in tubular 40 are utilized to supplement the function of a screen 80 . This is illustrated in FIG. 5 . Screens, it is known, cannot support any significant differential pressure without suffering catastrophic damage thereto. Utilizing the devices 10 as disclosed herein, however, a screen segment 82 can be made pressure differential insensitive by treating the devices 10 with a hardenable material as discussed above. The function of the screen can then be fully restored by dissolution or otherwise undermining of the hardenable material in the devices 10 .
[0026] Referring to FIG. 6 , an expandable liner 90 is illustrated having a number of beaded matrix areas 90 supplied thereon. These areas 92 are intended to be permeable or renderable impermeable as desired through means noted above but in addition allow the liner to be expanded to a generally cylindrical geometry upon the application of fluid pressure or mechanical expansion force. The liner 90 further provides flex channels 94 for fluid conveyance. Liner 90 provides for easy expansion due to the accordion-like nature thereof. It is to be understood, however, that the tubular of FIG. 2 is also expandable with known expansion methods and due to the relatively small change in the openings in tubular 40 for devices 10 , the devices 10 do not leak.
[0027] It is noted that while in each discussed embodiment the matrix 14 is disposed within a housing 12 that is itself attachable to the tubular 40 , it is possible to simply fill holes in the tubular 40 with the matrix 14 with much the same effect. In order to properly heat treat the tubular 40 to join the beads however, a longer oven would be required.
[0028] While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
|
A drill-in liner assembly including a tubular and a plurality of substantially radially oriented openings in the tubular arranged in a pattern; the pattern selected to substantially maintain torsional strength of the tubular while facilitating in-flow of target fluid. Also including a plurality of beaded matrix plugs disposed within one or more of the plurality of openings such that torsional load placed upon the plurality of openings in the tubular is borne by the plugs. An erosion resistant filtering arrangement including a tubular, a plurality of openings in the tubular arranged in a pattern, and a plurality of beaded matrix plugs disposed within one or more of the plurality of openings.
| 4
|
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to power supplies for electronic devices. More particularly, the present invention relates to an uninterruptible power supply to provide power to critical equipment.
[0003] 2. Discussion of the Related Art
[0004] Uninterruptible power supplies (UPSs) provide power to critical equipment that cannot experience any break in service. In other words, even a short duration brownout or blackout is unacceptable. Examples of such equipment include computer servers, computer networks, telecommunication electronics, medical devices, security networks, and the like. Regulated power is available no matter the status of the power supply.
[0005] Isolated power is important for these devices so that the input power is isolated from the output power. In short, UPSs use an isolation transformer to provide clean power to the device. An isolation transformer may have the same output voltage as input voltage. Isolation of the input and output power also prevents mutual interference, and may be required under certain conditions.
[0006] A device or equipment using a conventional UPS may include two modes of operation. First is an online mode using alternating current (AC) power applied to the primary winding. The online mode converts DC power that is rectified from an AC power input. The output power from the UPS may be reduced because of loss in the converting process.
[0007] The other mode may be called a bypass mode. If the online inverter circuit fails to provide power to the secondary winding, or load side, then a bypass circuit ensures power is provided from the power supply. The bypass mode can be implemented in two ways. One bypass mode configures the bypass power directly to the output power, thereby “bypassing” the transformer entirely. This mode does not isolate the input bypass power from the output power. If the bypass power is connected directly to the output, then any power spikes will be transferred to the output side of the power supply because the bypass is not isolated.
[0008] The other mode for providing bypass power uses a switch to apply the power to the primary winding of the transformer. Drawbacks of this configuration include a voltage interruption during the switchover of power, the output of the inverter circuit needs to be the same voltage as the input, and pulse-width modulation limitations that raise the possibility of distortion, which makes it difficult to compensate the voltage to keep the output of the inverter circuit the same. In terms of supplying uninterrupted power, a transient timing issue exists as the power supply switches from online inverter mode to bypass mode. Further, the bypass and online inverter circuits are connected to the same winding. Thus, the bypass voltage needs to be the same as the output voltage. This aspect results in unregulated voltage going to the primary winding and no adjustment available for the output voltage.
[0009] In summary, measures exist to provide uninterruptible power to devices and equipment. These measures, however, reduce the effectiveness of the power supply to provide isolated power, or result in temporary loss of power when switching to a bypass mode. Thus, these approaches fail to provide totally isolated output power in an uninterrupted manner.
SUMMARY
[0010] Accordingly, the disclosed embodiments of the present invention improve upon existing UPS technology and alleviate the drawbacks of conventional power supplies discussed above. The disclosed embodiments allow for greater control over the voltage applied to the primary windings and reduce any potential lapse in power during transition from online inverter mode to bypass mode. The disclosed embodiments perform these tasks while keeping the input power isolated from the output power.
[0011] The disclosed embodiments incorporate a double primary winding configuration for each mode. The primary windings fit each side's requirements. The configuration for the bypass mode may not be the same as one for the AC online inverter mode. Thus, any switchover from one mode to the other occurs continuously and without any interruption in service. Further, the disclosed embodiments include a circuit to control the output voltage in the online inverter mode based on the load condition.
[0012] As discussed above, a UPS device usually includes an online inverter circuit and a bypass circuit. The UPS device also may have a battery backup circuit. The online inverter circuit includes an AC-DC-AC converter that provides better quality power to the primary winding. The online inverter circuit takes an AC input and converts it to direct current (DC) power. The DC power is reconverted to AC power to supply “good” quality power. AC power is desirable to utilize the transformer in the power supply.
[0013] According to the disclosed embodiments, the output voltage is totally isolated from the AC input and bypass side of the power supply. The output voltage provided by the secondary winding while in the AC online inverter mode will be compensated output voltage by using the feedback of load current information. The disclosed embodiments also keep the desired sine waveforms for the alternating current by adjusting the switching pattern.
[0014] During the bypass mode, the disclosed embodiments isolate the output voltage from the AC input. Any surge voltage experienced within the power supply is isolated. Further, when in bypass mode, the voltage source differs from the source in the AC input side, which results in a different voltage level coming to the primary windings. The disclosed embodiments, however, provides the same output voltage via the secondary winding despite these differences.
[0015] According to the disclosed embodiments, an uninterruptible power supply is disclosed. The uninterruptible power supply includes an isolation transformer having dual primary windings and a secondary winding to supply an output voltage. A first winding of the dual primary windings is coupled to an inverter circuit that receives an alternating current input voltage. A second winding of the dual primary windings is coupled to a bypass circuit that receives a bypass voltage. Voltage is applied to the second winding upon failure of the inverter circuit to generate the output voltage without interruption.
[0016] Further according to the disclosed embodiments, an uninterruptible power supply includes an isolation transformer. The isolation transformer includes a first primary winding coupled to an inverter circuit that receives an alternating current input voltage, a second winding coupled to a bypass circuit that receives a bypass voltage, and a secondary winding. The inverter circuit includes a diode to generate a direct current voltage and an inverter to convert the direct current voltage to an alternating current voltage that receives a compensation voltage before being applied to the first primary winding. The alternating current voltage is cleaner than the alternating current input voltage. The uninterruptible power supply also includes a compensation circuit to detect a load current to the first primary winding and to generate the compensation voltage based on the load current. The uninterruptible power supply also includes an output coupled to the secondary winding to provide an output voltage corresponding to the bypass voltage or the alternating current voltage.
[0017] Further according to the disclosed embodiments, an isolation transformer is disclosed. The isolation transformer includes a first primary winding coupled to an inverter circuit. The inverter circuit provides an alternating current voltage to the first primary winding based on an alternating current input voltage. The isolation transformer also includes a second primary winding coupled to a bypass circuit to provide a bypass voltage. The isolation transformer also includes a secondary winding to generate an output voltage without interruption according to the first primary winding or the second primary winding. The second primary winding is used upon failure of the first primary winding.
[0018] Further according to the disclosed embodiments, a method for supplying power without interruption is disclosed. The method includes determining whether an inverter circuit is in a failure state. The method also includes applying an alternating current voltage using the inverter circuit to a first primary winding of an isolation transformer if the inverter circuit is not in the failure state. The method also includes applying a bypass voltage to a second primary winding of the isolation transformer if the inverter circuit is in the failure state. The method also includes generating an output voltage using a secondary winding of the isolation transformer based on the alternating current voltage or the bypass voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings are included to provide further understanding of the invention and constitute a part of the specification. The drawings listed below illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention, as disclosed in the claims.
[0020] FIG. 1 illustrates a block diagram of a power supply to provide power without interruption according to the disclosed embodiments.
[0021] FIG. 2 illustrates a graph showing the relationship between voltages within the inverter circuit and the load current according to the disclosed embodiments.
[0022] FIG. 3 illustrates a flowchart for providing power via an uninterruptible power supply according to the disclosed embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Reference will now be made in detail to the preferred embodiments of the present invention. Examples of the preferred embodiments are illustrated in the accompanying drawings. The preferred embodiments may include those variations readily available to one skilled in the art.
[0024] FIG. 1 depicts a power supply 100 according to the disclosed embodiments. Power supply 100 includes two circuits that supply power to isolation transformer 101 . Isolation transformer 101 separates the power applied in the primary windings from the power generated in the secondary winding. Isolation transformer 101 also may not include a wire or coupling to the ground so that one must come across both terminals to receive a shock. The primary circuit to supply voltage to a primary winding is inverter circuit 102 . If inverter circuit 102 fails or is off-line, then bypass circuit 104 applies voltage. Other circuits, such as a battery or backup circuit, also may be used, but or not shown. By using circuit 102 or 104 , output voltage Vout is generated at output 150 of power supply 100 .
[0025] AC power supply 108 provides input voltage Vin to circuit 102 . Diode 110 converts input voltage Vin into rectified DC voltage Vdc. Rectified DC voltage Vdc is applied to inverter 112 to generate AC voltage Vo. This process of going through diode 110 and inverter 112 results in a cleaner waveform for voltage Vo, which means cleaner power will be applied to primary winding 118 . The level of voltage Vo may be adjusted by a voltage Vc, disclosed in greater detail below.
[0026] Voltage Vo is filtered by a filter circuit comprising inductor 114 and capacitor 116 to generate voltage Va. Voltage Va creates load current I L that flows through primary winding 118 . Current I L creates a magnetic field in primary winding 118 that causes a magnetic field to bleed over to secondary winding 120 within transformer 101 . The magnetic field then generates current that results in output voltage Vout.
[0027] If circuit 102 fails or becomes unavailable, then bypass circuit 104 takes over. Bypass power supply 106 provides voltage Vb through circuit 104 . Voltage Vb generates current Ib that flows through primary winding 105 . Like winding 118 , winding 105 generates a magnetic field that bleeds over onto secondary winding 120 . The magnetic field applied to secondary winding 120 then creates a current that causes output voltage Vout at output 150 .
[0028] The disclosed embodiments may switch over from circuit 102 to bypass circuit 104 without the need of a switch that delays or interrupts the availability of output voltage Vout at output 150 . Further, primary windings 105 and 118 of transformer 101 isolate output 150 from the inputs, whether it is the regular AC voltage input or a bypass one, as bypass circuit 104 is not attached directly to secondary winding 120 .
[0029] Inductor 114 and capacitor 116 may serve as a filter circuit to filter voltage Vo and generate voltage Va. The filter circuit cleans up the waveform of the voltage in circuit 102 before load current I L enters primary winding 118 . Inductor 114 and capacitor 116 also reduce the ripple that results from rectification of the alternating current coming from inverter 112 . Cleaner power then may be provided to output 150 through transformer 101 . As shown in FIG. 1 , capacitor 116 is connected to a common line, or between phases, while inductor 114 is in line with inverter 112 and winding 118 . Values for inductor 114 and capacitor 116 may be adjustable depending on the specifications for power supply 100 . Moreover, other filter circuits may be provided along circuit 102 , as readily available to those skilled in the art. Other circuitry and devices also may be included within circuit 102 that provides a clean waveform for voltage Va.
[0030] Circuit 102 also includes a compensation component that serves to keep voltage Va at levels able to provide a constant output voltage Vout. The compensation component may include a current transformer 130 and a voltage compensator 132 . Voltage compensator 132 provides a compensation voltage Vc based on load current I L detected by current transformer, or detector, 130 as it flows to primary winding 118 . Current transformer 130 may be any detector known in the art.
[0031] Based on detected load current I L , voltage compensator 132 outputs voltage Vc to adjust the level of voltage Vo coming from inverter 112 . Thus, circuit 102 seeks to provide a constant output voltage Vout by adjusting Vo. Over time, load current I L increases as it flows into inductor 114 . As a result, voltage Va may decrease as well which cause a lower voltage to be applied to secondary winding 120 , and voltage Vout also will decrease due to the impedence of the transformer. To keep the output voltage constant, voltage compensator 132 provides voltage Vc to compensate for those voltage drops due to load current.
[0032] Alternatively, the voltage level applied by AC power supply 108 may drop as it is converted to DC and then back to AC voltage in circuit 102 . Voltage Vc also may be used to adjust the voltage applied to primary winding 118 to remain constant by adjusting the voltage for any drops experienced in circuit 102 .
[0033] Referring to FIG. 2 , a graph 200 depicts the relationship between voltages Vo and Vout, and load current I L in this application. The horizontal axis represents the increasing value of load current I L as it flows into primary winding 118 . As load current I L increases, the value of voltage Vo increases as well as the output voltage remains substantially the same during operations.
[0034] The disclosed embodiments employ voltage compensator 132 to adjust voltage Vo to the level shown by the line for voltage Vo. As shown, voltage Vout remains the same even as load current I L increases. The difference between voltages Va and Vo may be shown by voltage Vc, provided by voltage compensator 132 , as disclosed above. Thus, according to the disclosed embodiments, a constant output voltage Vout is provided by power supply 100 because the voltage applied to primary winding 118 remains constant.
[0035] FIG. 3 depicts a flowchart 300 for providing power via an uninterruptible power supply according to the disclosed embodiments. For simplicity, reference will be made to the features of the disclosed embodiments shown in FIG. 1 by power supply 100 .
[0036] Step 302 executes by activating power supply 100 to provide voltage Vout at output 150 . Voltage Vout preferably is provided without interruption and at an approximately constant level. Step 304 executes by determining whether the circuit for providing the power has failed, such as inverter circuit 102 . Inverter circuit 102 may be determined to be in a failure state if it is not capable of receiving the alternating current input voltage, or if any of its components are inoperable. Moreover, the failure state may exist is a spike occurred that shuts down inverter circuit 102 . Thus, the primary circuit for providing power to the secondary side of the isolation transformer has failed.
[0037] If step 304 is no, then step 306 executes by receiving the AC input voltage, or voltage Vac. Step 308 executes by converting the AC input voltage to DC voltage, or voltage Vdc. Step 310 executes by converting the DC voltage back to AC voltage, or voltage Vo. This process serves to clean up and rectify the waveform of the voltage applied to primary winding 118 of transformer 101 .
[0038] Step 312 executes by filtering the waveform of voltage Vo to generate voltage Va. The flowchart may then proceed to step 320 directly or, after a set period of time, certain conditions and the like, proceed to step 314 to determine if the load current flowing into primary winding 118 is acceptable. Thus, step 314 executes by detecting the load current that is used to generate the magnetic field in transformer 101 . Step 316 executes by determining whether the load current is acceptable. The load current may be unacceptable if it results in the voltage generated at output 150 being too high or low. In other words, if output voltage Vout fluctuates beyond the level desired, then the load current is unacceptable.
[0039] If step 316 is yes, then flowchart 300 proceeds to step 320 , as disclosed below. If step 316 is no, then step 318 executes by adjusting voltage applied to primary winding 118 to remain constant. Compensation voltage Vc is applied to adjust voltage Vo to the acceptable level for constant output, or voltage Va.
[0040] Step 320 executes by applying voltage Va to primary winding 118 using the load current. Step 320 may be executed directly after filtering the waveform, or after any adjustments are made to the voltage level. Flowchart 300 then proceeds to step 326 , as disclosed below.
[0041] Referring back to step 304 , if inverter circuit 102 fails, then bypass circuit 104 is used to supply the power at output 150 of power supply 100 . Thus, step 304 determines a “yes” condition. Step 322 executes by receiving bypass voltage Vb at circuit 104 . Step 324 executes by applying voltage Vb to primary winding 105 within transformer 101 . Step 324 and step 320 are shown separately because the voltages are not applied to the same winding, but to one of two independent windings within transformer 101 . Thus, transformer 101 uses two separate, isolated primary windings 105 and 118 .
[0042] After execution of step 320 or step 324 , step 326 executes by generating a magnetic field within transformer 101 . Current flows through the applicable winding to create the magnetic field. The magnetic field bleeds over to secondary winding 118 to generate a current within the winding. As a load is applied to secondary winding 118 , voltage Vout is generated, as executed in step 328 .
[0043] For example, an output voltage Vout of 480 volts may be desired. Thus, the AC input voltage and bypass voltage may be 480 volts at 60 Hertz. Further, voltage Va applied to primary winding 118 may be an AC voltage of 480 volts. Alternatively, transformer 101 may step up or step down voltage levels as desired. Thus, if the input voltage to power supply is 480 volts but the desired output voltage is 208 volts, then the number of windings within primary windings 105 and 118 and secondary winding 120 may be adjusted accordingly.
[0044] Further, primary windings 105 and 118 may differ as the voltages available in inverter circuit 102 and bypass circuit 104 differ. For example, the voltage applied to primary winding 118 , or voltage Va, may be 300 volts while the bypass voltage is 480 volts. Transformer 101 may step up the voltage to result in an output voltage of 480 volts. Thus, inverter circuit 102 may stay at more manageable or safer levels during normal operations of power supply 100 .
[0045] It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed embodiments of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of the embodiments disclosed above provided that they come within the scope of any claims and their equivalents.
|
An uninterruptible power supply includes an isolation transformer having dual primary windings. The secondary winding generates an output voltage based on the magnetic field generated in one of the dual primary windings. A first primary winding is coupled to an inverter circuit that receives an alternating current input voltage and applies a clean and filter alternating current to the first primary winding. A second primary winding is coupled to a bypass circuit that applies a bypass voltage when the inverter circuit is in a failure state. The power supply also includes a compensation circuit to maintain the output voltage at a desired level.
| 7
|
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/912,489 filed 18 Apr. 2007 the entire file wrapper contents of which are incorporated herein as if set forth at length.
FIELD OF THE INVENTION
This invention relates generally to the field of wireless sensor networks in particular to a software architecture and associated methods that provide fine-grained visibility and control of sensor node software in a minimally-intrusive manner.
BACKGROUND OF THE INVENTION
As wireless sensor systems and networks thereof transition from research prototypes to commercial deployment their reliable and dependable operation is crucial to widespread adoption and commercial success. Unreliable sensor network operation is oftentimes the result of one or more of the following events: (a) hardware faults (e.g., failure of hardware components such as sensors), (b) software problems (e.g., bugs, incorrect program logic, unsafe operations), or (c) networking issues (e.g., interference, collisions).
Those skilled in the art will readily appreciate that ensuring reliable software operation in wireless sensor networks offers an extremely challenging set of problems. In particular, a combination of severe resource constraints, lack of architectural safety features such as memory protection, and operation in unpredictable environments leads to uncommon and unexpected failures in sensor networks that oftentimes manifest themselves only at run-time through complex trigger mechanisms. As a result, pre-deployment testing using conventional quality assurance tools such as simulators is not sufficient as it does not accurately reflect the sensor system's post-deployment behavior. Consequently—for contemporary sensor systems—in-field testing and validation of deployed systems is necessary.
For post-deployment testing, the more “visibility” a software designer can obtain into program behavior as it executes in-field, the easier the program will be to test, analyze, validate, and if needed, debug. Furthermore, visibility is essential for exercising control (e.g., to correct/mask errors, access control, resource allocation) over software execution in deployed sensor nodes. Unfortunately, obtaining fine-grained visibility into a running software system is hard in any embedded system and even harder in sensor networks where the nodes under test may be several wireless hops away.
SUMMARY OF THE INVENTION
The above problems are solved and an advance is made in the art according to the principles of the present invention directed to a computer-implemented framework, prototype tool and associated methods that provide a high degree of visibility and control over the in-field execution of software in a minimally intrusive manner.
According to an aspect of the present invention, developer-defined correctness tests and validation logic are embedded into the sensor node itself, making in-field software testing autonomous without continuous developer participation. Importantly, developers are able to push corrective actions onto the node under test, which automatically get invoked when anomalous software behavior occurs.
In sharp contrast to prior-art approaches to sensor node software which employ interactive debugging methodologies that ferry debugging information between a node under test and a developer and require continuous developer participation during testing, the present invention embeds developer-defined correctness tests and validation logic into the sensor node itself, making in-field software testing autonomous.
Advantageously, the present invention present invention does not involve the debugging of individual lines of source code, rather it operates at a higher level of abstraction to provide run-time visibility and control over the interactions of larger units of functionality (e.g., tasks, modules, threads). Consequently, it permits high-level functionality testing while answering questions that are meaningful in the context of the application (e.g., whether the sensor driver returns sensed data when requested and what the observed range of the sampled values is).
Of particular advantage, and according to yet another aspect of the present invention, visibility and control are provided in a non-intrusive manner. No change is required to the source code of the software being tested and debugged. In fact, the target software as well as other software components that it interacts with are oblivious to the testing and continue to operate normally.
Operationally, the present invention achieves these advantages by interposing the target software's data-flow interactions (such as messages) and control-flow interactions (such as inter-process communication calls, system calls, and calls to event handlers) with the rest of the system. As a result, sensor network designers can not only analyze and verify the behavior of remotely deployed nodes, but also easily detect (and often even prevent) incorrect and unreliable operation.
BRIEF DESCRIPTION OF THE DRAWING
A more complete understanding of the present invention may be realized by reference to the accompanying drawing in which:
FIG. 1 is a schematic block diagram showing the overall interposition architecture and associated components of the present invention;
FIG. 2 is a schematic block diagram depicting interposition according to the present inventions for FIG. 2(A) interaction of module A in SOS; and FIG. 2(B) interposition of module A by module IA in SOS with interposition enabled;
FIG. 3 shows code segments for FIG. 3(A) interposing a cross-module function call from Surge to Tree; and FIG. 3(B) for Surge and Tree Routing showing the call site and native function cal implementation.
FIG. 4 is a graph showing RATS synchronization error (ms) vs. Experiment time (s);
FIG. 5 is a pair of graphs showing delivery latency of SURGE packets FIG. 5(A) from a base station; and FIG. 5(B) a node 4 hops away; and
FIG. 6 is a bar graph showing the number of packets delivered to the base station.
DETAILED DESCRIPTION
The following merely illustrates the principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope.
Furthermore, all examples and conditional language recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions.
Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.
Thus, for example, the diagrams herein represent conceptual views of illustrative structures embodying the principles of the invention. We initially present an overview of the present invention and its design principles. At this point, we intentionally keep the description generic to the extent possible.
Overview
For purposes of illustration, consider a software system running on a sensor node to be comprised of one or more software modules, i.e., segments of code componentized by functionality. As can be readily understood by those skilled in the art, a number of sensor operating systems have embraced such modularity in their run-time software architecture (e.g., modules, processes, and threads).
By definition, software modules that are part of a larger software system use a set of well-defined interfaces to interact with the rest of the system. These interfaces, which represent a boundary of a software module with its environment, present—according to the present invention—a natural opportunity for our inventive interposition approach.
With initial reference to FIG. 1 , there is shown a schematic diagram depicting the principles of module interposition according to the present invention. For our purposes and as used herein, we have named our inventive system “HERMES”. As preferably implemented, software modules link and interact directly with one or more runtime libraries during normal execution. An underlying principle—according to the present invention—is that an additional software component (referred to as the interposition module) is interposed between a module (referred to as the target module) and the sensor runtime. Advantageously, the interposition module can then observe and control the interactions to and from the target module.
With continued reference to that FIG. 1 , there it may be seen that interposing a target module is a two-step process. The first step, shown in the dashed box 101 , is performed off-line and involves the generation of a customized interposition stub 105 based on the interfaces used and provided by the target module. Accordingly, a target module's source code 102 is parsed via compiler tool suite 103 which determines any specific interfaces that the target module uses to interact with any runtime modules, and automatically synthesizes a template interposition stub 105 customized for that target module 102 .
We refer to it as a template interposition stub 105 since its functionality may be extended to support advanced interposition tasks. The stub 105 is packaged by compiler tool suite 106 into an interposition binary module 107 that is now ready for interposing the target.
The second step in our inventive interposition process, shown in FIG. 1 by the dashed box 150 on the right, involves the insertion of the interposition module into the original running system, to interpose the interfaces between the target module and the runtime.
As may now be appreciated by those skilled in the art, for sensor operating systems, the interfaces that need to be interposed can be categorized as (i) functions provided by the target module, (ii) handlers for events and messages received from other modules and the runtime, and (iii) functions provided by the sensor runtime and other modules that are invoked or otherwise used by the running target module.
Upon insertion, the interposition module provides to the runtime, a handler or function corresponding to each handler or function provided by the target module. Similarly, for every function invoked by the target module into the runtime or another module, the interposition module presents a corresponding interface to the target module. The interposition module thus mimics the runtime from the target module's perspective and the target module from the runtime's perspective.
Design Principles
According to an aspect of the present invention, we provide a powerful, flexible, and lightweight mechanism to observe and control the in-field behavior of sensor software. To implement such mechanism(s), a number of design principles were developed.
Dynamic extensibility: The true potential of a framework to observe and control post-deployment behavior can be realized only if it allows users to easily introduce, change, and remove interposition functionality in an incremental manner as needed. Unforeseen failures and other scenarios encountered in sensor deployments demand such dynamic extensions. As can be appreciated, requiring interposition functionality to be completely incorporated or otherwise embedded into the sensor software prior to deployment, would either restrict the type of changes possible to the interposition functionality or require the node's entire binary image to be recompiled and redistributed for each change.
Advantageously, and as previously noted, there are several sensor runtimes that support dynamic software extensibility. Additionally, even runtimes with monolithic binaries are often amenable to dynamic extensibility with some effort. For example, add-ons or application-specific virtual machines may provide techniques sufficient to achieve dynamic extensibility. In prototype implementations—our inventive HERMES was carried out on the SOS operating system that supports dynamic extensibility.
Flexibility in interposition granularity: Since the level at which software behavior is observed may determine both the degree of understanding and the type of control that can be exercised over the behavior, it is necessary to allow for several vantage points to suit varied requirements. For example, a developer interested in tapping outgoing packets from a node would prefer to just tap into a node's radio interface rather than the messaging interface of each module.
In the design of H ERMES , the module interface was chosen as it advantageously allowed such latitude. H ERMES can interpose a subset of the module's interfaces (one function at its minimum), several modules at once, the communication interface (network driver module) out of a sensor node, or even several nodes at once, thus providing several choices in granularity. Further, in operating systems such as SOS, Contiki, and M ANTIS , modules can represent applications, middleware, or even extensible kernel components (e.g., sensor drivers), making H ERMES even more powerful.
Non-intrusiveness: Non-intrusiveness refers to the extent to which the original behavior of the system is affected due to providing visibility and control. While interposition naturally carries overhead, it must not significantly alter the execution of the software. Further, developers should have the ability to turn up or turn down the extent of interposition based on the permissible overhead.
H ERMES supports selective interposition both temporally, i.e. can be turned on and off dynamically, and spatially, i.e., can be applied to a subset of interfaces. Second, unlike over-the-network debuggers such as Marionette, H ERMES does not interrupt execution to gather information, providing visibility and control while the software continues to execute normally. Third, H ERMES does not require any modification to the source code of the module being interposed. In fact, the target module is completely oblivious to the interposition itself.
Ease of use: Finally, H ERMES makes it easy for developers to write the code that enables visibility and control by automatically synthesizing code stubs that handle the mechanical details of the interposition. Developers only need to fill these stubs with the logic needed to operate on the interposed observations. In other words, we provide ready-made hooks for visibility and control of the target module, but give the developer complete freedom to use these hooks as desired. For example, a designer may choose to just log a target module's interactions with the rest of the system, or choose to trap, modify, or even suppress them.
Usage Scenarios for Hermes
The H ERMES interposition framework can be used to implement a variety of observe and control functions desired for deployed sensor networks. Below, we briefly describe some envisioned uses of H ERMES . In Section 2, we detail three specific case studies implemented using H ERMES.
Observing In-Field Execution
In its most basic form, the H ERMES framework can be used to enable a high degree of visibility into software execution on remote sensor nodes. In addition to the ability to record and timestamp inter-module interactions, the interposition code also has limited visibility into the state of the module being interposed, i.e., as allowed by the state-access hooks available within the runtime. Traces of the functions of a module that were invoked, when they were invoked, the parameters passed with these calls, and how the module's internal state changed as a result of these calls are obtainable using H ERMES . Further, H ERMES also enables the following more advanced forms of visibility:
Conditional Watchpoints Based on In-Field events: Since developers can explicitly specify which interactions to interpose, when to interpose, and what to do with the interposed interaction, debugging tasks can be dynamically triggered in response to specific in-field events. For example, receiving a packet from a new neighbor node or a message with a certain payload can be used to trigger a detailed execution trace. Such conditional visibility is attractive from an overhead point of view, and is a useful contrast over interactive, over-the-network debuggers.
Synthetic event generation and in-field testing: Since H ERMES allows observing and controlling a module's interactions, one can present an alternate behavior of the module to its surroundings—a useful feature for applications. For example, in a network deployed for wildfire monitoring, interposition modules inserted at specific nodes in the network can synthesize sensor traces to mimic fire events. The subsequent response of the network can help verify the readiness of the deployment—similar to real-world fire drills.
Controlling In-Field Execution A broad set of network management and maintenance operations can be easily implemented through H ERMES . Below, we outline uses that emphasize H ERMES 's ability to control the interactions of a target module.
Dynamic access control policies: Since the functionality of a deployment can be compromised or disrupted due to faulty or malicious nodes, it is necessary to have the ability to quarantine specific nodes and limit the disruption. Clearly, such measures need to be both dynamic and ad hoc to handle security emergencies unforeseen at the time of deployment. H ERMES can be used to interpose and hence tap into the network stack, to dynamically add appropriate firewall rules at the nodes neighboring the rogue nodes.
Traffic shaping to manage shared network resources: Resources such as the limited wireless bandwidth must be carefully allocated to suitably address metrics such as fairness and network longevity. Several factors must be considered and these factors could vary drastically over time, driving a need for dynamic adoption of allocation policies. By interposing the communication path, H ERMES can be used to dynamically (and with little overhead and disruption) introduce resource allocation policies to adapt to changing network conditions.
Fixing isolated in-field failures: Sensor network deployments will continue to be marred by failures due to hostile environments, unreliable hardware, and buggy software. H ERMES can be used to architect both preventive mechanisms (e.g., forcing a fail-safe operation upon seeing an illegal interaction) and, at the other end of the spectrum, recovery mechanisms (e.g., stateful rollback using interaction traces). However, we expect to see H ERMES being particularly useful for emergency recovery measures under isolated failures, especially in critical deployments. Certain hardware failures of a sensor node can be detected and masked to keep the sensor node as a whole operational, until a more comprehensive corrective action can be taken. For example, upon detecting a bad reading from a temperature sensor (say the sensor becomes stuck at zero—a common), a stub interposing the sensor driver could substitute the reading with an acceptable one estimated either from prior readings or from those of its neighbor, as well as report the error to the network operator. Of course, the temperature example is just that—one example. Other sensor(s) responses such as pressure, etc may advantageously employ the same methodologies as this exemplary temperature.
Implementation
Implementing H ERMES for any sensor runtime poses a number of challenges. First, we require the interposition to be transparent to the module being interposed, as well as to other modules in the system. This implies that no changes should be made to the source code of the target module or other modules while also providing transparency at runtime. Second, to allow flexible use of interposition capability one should dynamically configure interposition not only for any module in the system, but also for a subset of interfaces of each module. This configuration needs to be atomic with respect to the modules in the system. Finally, the H ERMES implementation should have a low memory and computational footprint, so that it does not affect the performance of the system. Our prototype implementation of H ERMES for the SOS operating system, described below, addresses these specific challenges.
SOS—A Modular Sensor Network OS
SOS is a sensor operating system with a structured architecture based on a small kernel that is installed on all the nodes in the network. The rest of the system and the application functionality are implemented as a set of dynamically loadable binary modules. This modularity forms the basis of the SOS architecture, as it defines distinct boundaries and allows modules to be loaded and unloaded at runtime.
SOS provides an event-driven execution model, with each module implementing a handler that is invoked by the OS scheduler to dispatch messages to destination modules. Modules interact with one another and with the kernel through both synchronous function calls and asynchronous messages. FIG. 2(A) shows the basic architecture of SOS and the well-defined communication paths for modules to interact with each other and with the kernel. These paths provide definite points for the SOS kernel to track execution context, e.g., when messages cross module boundaries.
Synchronous communication between modules is implemented by SOS using dynamic linking. A module's binary encodes the set of functions it provides and those it subscribes to. At load time, the dynamic linker tracks down and links all the provide-subscribe function pairs. Modules can also send asynchronous messages to each other by posting them to a queue managed by the scheduler, which invokes the message handler of the destination module. The module-kernel interaction takes place via API system calls (to kernel) and asynchronous messages (from kernel).
Hermes Implementation Overview
Our H ERMES prototype exploits the clean module-to-module and module-to-kernel communication paths in SOS to provide the network designer with the capability of trapping all interactions of a user module with the rest of the system (function calls and messages both directed to and from a target module) at the module boundaries. As may be observed in FIG. 2(B) , H ERMES redirects trapped interactions to an interposition module specific to the target module.
Advantageously, and according to the present invention, a target module can have its own dedicated interposition module, or a single interposition module may serve multiple target modules. Consequently, H ERMES increases the number of modules present in the system only marginally.
Interposition is completely transparent as: (i) no changes are required to a target module's source code to enable interposition, and (ii) no other module the target interacts with is aware of the interposition. In addition, interposition is also dynamic and selective, i.e., it can be turned on or off at runtime, and a programmer can choose which interactions of the target to interpose. In summary, H ERMES provides flexible interposition at the granularity of individual function calls and messages, with minimal footprint on the system.
H ERMES achieves transparent interposition by adding light-weight support for interaction redirection in the SOS kernel and by leveraging the dynamic linking mechanism used in SOS. For dynamic interposition control, H ERMES provides a new SOS kernel function that can be used to switch interposition on or off for a given target module. H ERMES ensures that transitions of the target module between the interposed and non-interposed states are atomic.
To simplify a programmer's task in using H ERMES , we have developed tools that automatically generate a skeleton of the interposition module from the code of a target module. The actual functionality of the interposition module is provided by the developer, thus granting him/her the flexibility of choosing what to do with the interposed interactions.
Runtime Interposition System
H ERMES interposes three types of interactions of a module with the rest of the system: (i) kernel API calls (with the kernel); (ii) subscribed/provided user function calls (with other modules); (iii) messages (with kernel, other modules, and network). We now describe the mechanisms used in our modified SOS kernel to redirect these interactions, as well as to enable dynamic interposition control.
Kernel Call Redirection
To intercept and redirect all kernel API calls made by the interposed module to functions provided by the interposition module, we augment all kernel functions with a prologue consisting of a few lines of redirection code. The redirection code checks if the calling module is interposed and if its interposition module provides an alternate function to substitute for the kernel call. If so, it calls the alternate function provided by the interposition module, otherwise it falls through to the default kernel call implementation.
The alternate implementation of a kernel call provided by the interposition module may in turn make kernel calls, including the redirected one, e.g., after logging it, changing its parameters, etc. This could result in loopback redirection (thus infinite recursion). To avoid it, we track the context from which a kernel call is made, and distinguish between calls made from within an interposed module (to be redirected) and calls made after control crosses module's boundaries (to fall through).
Cross-module Call Redirection
The kernel redirects cross-module calls issued by and to an interposed module to their corresponding implementations provided by its interposition module, using the dynamic linking facility provided by SOS. This redirection is performed when either a new module is inserted into the system or when interposition is turned on for an existing module. Non-interposed functions of the target module are linked directly to their real implementations, with no additional call overhead.
The kernel performs the following steps when loading and linking a new module M: (i) if an interposition module for M is already present in the system and interposition is turned on for M, link all of M's subscribed and provided functions to the interposition module; (ii) if M subscribes to functions provided by an already interposed module, link M to the respective interposition module; (iii) if an interposed module subscribed to M's functions, do not link that module to M (since it is already linked to the function provided by its interposition module).
The kernel performs the following steps when interposition is turned on dynamically for a module M: (i) re-link the functions subscribed to by M to the corresponding functions provided by its interposition module; (ii) re-link the subscribers of every function provided by M to the corresponding function provided by M's interposition module.
When interposition is dynamically turned off for M, the kernel simply uses the default linking mechanism of SOS to re-link M into the system. In our implementation, the above steps are guaranteed to be atomic with respect to a target's interactions with other modules since they are either executed in the nonpreemptible message handler of the kernel loader or as a result of a system call made from the nonpreemptible message handler of a user module.
Incoming Message Redirection
The kernel redirects a message sent to an interposed module to the corresponding interposition module by checking if the destination module is interposed, and, if so, diverting the message to the handler within the interposition module. The kernel also transfers memory ownership of the diverted message's payload to the interposition module. Upon receiving the message, the interposition module can use the (unmodified) destination field of the message to discriminate between redirected messages and those actually intended for it.
Outgoing Message Redirection
In SOS, messages are sent by a user module using one of the post_* kernel API calls. Since all kernel functions are redirected to the interposition module of the caller module (if any), all messages originating in an interposed module are automatically redirected to the interposition module.
Dynamic Interposition Control
The kernel provides dynamic interposition control at runtime. A field in the kernel module descriptor stores a pointer to the module's interposition module, if any. This field is used to control the module's interposition status (on/off) and can be set/unset using a kernel API function provided by our modified SOS kernel. The interposition module also stores a duplicate of the interposition status in a reserved field in its module-specific state. This copy acts as a backup in case the target module is removed from the system while interposition is still turned on, or if interposition is turned on before insertion of the target module. Upon loading a module whose interposition module is already present in the system, this field is checked to determine whether or not the new module's interactions need to be redirected. This enables per-module dynamic control of the kernel redirection mechanisms without removing the interposition module from the system or restarting it, even when the target is absent from the system.
Interposition-stub Synthesis As described in the previous section, the H ERMES runtime interposition system redirects, to the interposition module, all the cross-module calls to and from its target module, the kernel calls that the target makes, and the messages that the target sends or receives. Consequently, an interposition module's code will have a structure specific to the module it interposes. H ERMES provides a preprocessor to automatically generate a customized stub of the interposition module from the source code of its target module. This tool is built over the CIL compiler framework for C.
The preprocessor takes as input the target module to be interposed and generates an interposition module containing stubs for certain types of functions to which the kernel redirects calls to/from the target: (i) functions provided by the interposed module (to which the kernel redirects calls made by other modules), (ii) functions subscribed to by the interposed module (to which the kernel redirects calls made by the interposed module), and (iii) kernel API functions used by the interposed module (to which the kernel redirects kernel calls made by the interposed module).
To further ease the programmer's burden, the preprocessor builds in default “null” functionality into the generated interposition module, such that directly running it causes interposed interactions to be simply redirected to their original intended target. With this default functionality in place, the programmer need only modify code to handle the specific interactions to be interposed.
FIG. 3 shows an example of coding cross-module call interposition for the Surge application module. The interposition module ( FIG. 3A ) implements the inter_get_hdr_size function, whose stub had been generated by our preprocessor since the Surge module calls the tr_get_hdr_size function provided by the TreeRouting module ( FIG. 3B ). The programmer has filled in code in the stub to return a header size of zero. If the programmer chooses not to interpose this function, it's entry can simply be removed from the list of provided functions in the module's header shown at the top. Note that H ERMES imposes no restriction on how the original application ( FIG. 3B ) itself is written.
Discussion
We described in this section our implementation of H ERMES for SOS. The architecture of H ERMES is, however, general and can be implemented over a variety of other operating systems. For multi-threaded operating systems such as Contiki and M ANTIS —which have dynamic linking capabilities—our technique for modifying the dynamic linking mechanism may be extended thereby allowing for the interposition of individual threads. Our inventive technique could also be applied to other systems such as TinyOS, using capabilities such as FlexCup, which enables dynamic linking for TinyOS. For plain TinyOS, which does not provide for dynamic linking, interposition can either be applied at compile-time, or at runtime using binary rewriting in an approach similar to the one taken by Clairvoyant.
Evaluation
We performed an evaluation of our implementation of H ERMES for SOS running Surge, a sensor data collection application. A distributed tree routing protocol (implemented by the TreeRouting module running on every node) builds a routing tree rooted at the base station, which is used by the Surge module at each node to send collected data towards the base station. We micro-benchmark the overhead introduced by H ERMES using Avrora, a cycle-accurate simulator for the Atmel AVR instruction set architecture. We also present performance statistics of H ERMES on the MicaZ sensor platform.
In the evaluation, we simulated Surge in Avrora, running it on two systems: over the plain SOS, and over SOS with our H ERMES implementation (SOS+H ERMES ). In the SOS+H ERMES case, we introduced an interposition module for Surge and ran the simulation twice, once with interposition for Surge turned off, and then with interposition turned on. We used the “null-interposition” module generated by the H ERMES preprocessor that simply redirects all function calls and messages to their original destinations, without performing any computation or buffering them. We ran simulations for 500 seconds using three nodes located within one hop of each other and collected statistics using the profiling facilities in Avrora.
We first evaluate the absolute overheads introduced by H ERMES in cross-module and kernel call redirection. Table 1 presents call latencies for three functions, for each of SOS and SOS+H ERMES , in the two cases of interposition off and on for Surge. The first two functions are representative of typical module interactions via kernel and inter-module calls. ker_id is a kernel function that returns a module's ID. tr_get_hdr_size is a function provided by TreeRouting that is subscribed to and called by Surge upon sending a packet. The third function, inter_get_ker_func, is a lookup function added by H ERMES to the SOS kernel and called from all kernel functions. If the module where the kernel call originated is interposed, it returns a pointer to the alternate implementation of the kernel function provided by the interposition module.
As shown in Table 1, for cross-module tr_get_hdr_size calls, the latency increases to 112 cycles with interposition on, due to a lookup of the interposition module's header that the module itself must perform in order to find the target function. inter_get_ker_func takes 23 cycles with interposition off. With interposition on, it takes a variable number of cycles depending on the call site (listed in parenthesis in Table 1), with a maximum of about 350 cycles when called from within Surge.
The module ker_id takes 40 cycles in SOS+H ERMES even when interposition is off, due to interposition checks introduced by H ERMES —a baseline overhead. When interposition is on, it takes 467 cycles. This steep hike is due to a call to our suboptimal implementation of the inter_get_ker_func lookup function, the rest being due to ker_id needing to be redirected twice, once from the kernel to the interposition module, and then from the interposition module to the kernel. Although these numbers may seem high when compared to the plain SOS, we next show that their effect on the overall system performance of Surge is negligible.
In our next evaluation, we repeated the previous runs on a real sensor testbed of ten MicaZ motes, out of which one was the base station and the others were simple Surge nodes, up to two hops away from it. The execution runs took about 1,000 seconds. We used the Rate Adaptive Time Synchronization (RATS) protocol to time-synchronize the nodes and collected statistics on packet latency and number of packets delivered to the base station.
Table 2 presents memory usage and performance statistics for Surge on plain SOS, and on SOS+H ERMES in four cases: no interposition module, Surge interposition module loaded with interposition off and on, respectively, and both Surge and TreeRouting interposed. The last four columns show the performance metrics, demonstrating that interposing Surge and TreeRouting does not impact their operation, as the number of packets delivered remains practically the same for all the scenarios (small fluctuations are due to packet losses caused by wireless link quality). Moreover, the increase in packet latency for a non-base station node in the SOS+H ERMES case, expected due to the overhead introduced by H ERMES , is only about 3% in the worst case (both modules interposed). For the base station, the relative increase is higher because of the much smaller delivery latency in the base case. We also measured that it takes 2,223 cycles to turn interposition on, which is negligible as compared to around 22 ms taken to load a new module into the system in SOS. We hence conclude that interposition does not significantly impact the performance of the Surge application.
In terms of memory usage, both SOS and SOS+H ERMES have the same static RAM footprint, while H ERMES causes only a marginal increase in dynamically allocated memory (heap). Note that more than one module can be interposed with no increase in memory footprint. The stack size exhibits a small increase with interposition on, due to extra calls redirected through the interposition module. H ERMES adds about 8 KB to the SOS code size (ROM usage). The interposition module that we used further increases the code size by about 1 KB.
Case Studies
Debugging and Verification
We have described the utility of H ERMES as a tool for debugging and monitoring software functionality post-deployment. This case study explores this aspect of H ERMES further by using it to debug and verify the functionality of a specific software component, namely the RATS time-synchronization protocol.
RATS provides pairwise time synchronization between sensor nodes. A client node that wishes to synchronize its time with a server node receives periodic time-stamped messages from the server node, which it time-stamps upon reception with its current clock value. The client thus maintains a sequence of tuples comprised of its and the server's time-stamps. When queried to convert a given local time into the server's time, the client uses regression to compute an estimate from these tuples.
We design an interposition module to provide visibility into the functioning of RATS. The interposition module intercepts all incoming time-stamp messages for the RATS module at the client. When a time-stamp message arrives from the server, the interposition module extracts the time-stamp values for the server and the client from the message. It then queries the RATS module for an estimated time at the server matching the time-stamp at the client.
It compares the value RATS returns (which is an estimate) with the real server time-stamp to compute the actual error after factoring in transmission delay. The interposition module then copies a snapshot of the state of the RATS module, along with this actual error value, into a packet, and sends it to the base station. It then passes the received time-stamp message through to the RATS module, which continues to function normally.
Even this simple interposition module provides us a lot of visibility into the RATS protocol. We are able to observe exactly when time-stamp messages are received by the client and how its state changes as a result. We are also able to gather insight into the protocol's performance through online computation of the actual error in time synchronization. Note that it is possible to code more sophisticated interposition functionality to get even more insight into the operation of RATS. For instance, one may use the interposition module to model network/node failures or corrupted time-stamps and observe how RATS responds.
Evaluation
We implemented the above described interposition module and evaluated it on two MicaZ motes. We instrumented Surge to use RATS and ran it on both motes for 200 minutes. The base station acted as the RATS server and the other node as the client that tries to synchronize its time with the base station to within a preset error limit of 1 ms. The interposition module at the client sends back snapshots of the state of the RATS module, along with the computed error, in response to the arrival of new time-stamped packets from the base station.
FIG. 4 plots the actual error calculated by the interposition module versus the time at which the client node received the time-stamped packets. The data verifies the functionality of the RATS protocol in several ways: (i) it validates the way in which RATS adapts its rate of time-stamped packets to the error in time synchronization.
The rate decreases exponentially if the estimated error goes down, and it is increased in response to increases in the error; (ii) it verifies that the estimated error used by RATS to adapt its rate is a good approximation of the actual error: when the actual error calculated independently by the interposition module increased above the acceptable limit of 1 ms set by the Surge module (at 8,000 seconds into the run), RATS doubled its rate of sending time-stamped messages.
Note that, while the interposition module was running, Surge packets were also being sent to the base station. With interposition on, the measured average latency of Surge packets increased from 27 ms to 29 ms, compared with plain SOS, while the number of packets received at the base station remained the same. Thus, the Surge module was negligibly affected due to our testing of RATS and the extra burden on the routing module.
Transparent Software Updates
In a functional sensor network deployment, it may become necessary to update a software module on some or all of the sensor nodes. Dynamic updates might be required in order to fix software bugs, introduce additional features, or tune operational parameters. At the same time, the module being updated may be critical to the functionality of the deployment, requiring the update process to be transparent. Routing is one such critical service. An interruption to update the routing module would not only disrupt communication temporarily, but may also result in sub-par performance upon service resumption due to loss of routing state.
H ERMES can be used to eliminate the outage caused by updates to such critical modules. Instead of replacing the old version of the module by the updated copy and taking a service disruption, we may advantageously run the two versions simultaneously for the duration required by the new version to warm-up, i.e., build its service state. During the warm-up phase, we interpose both versions of the module to: (i) hide the presence of the updated copy from the rest of the system; (ii) keep the old version online and continue to use it to answer service requests; and to (iii) fork messages sent to the old version over to the new module to help it build service state. Thus, while the updated copy is building state, the old version of the module is ensuring that the sensor network remains operational. Once the updated copy warms up, the old version of the module and the interposition module are removed and the updated module continues servicing requests without any interruption.
We implemented the transparent update feature for the tree-routing module using our H ERMES prototype as a case study. In order to deal with the issue that SOS does not allow multiple modules with the same process ID, we introduce a “back-up” module—identical in functionality to the original tree routing module but with a different process ID, to which the original module's state is copied over to function as it's substitute (via interposition). It should be noted here that no changes were required to the H ERMES implementation for SOS to implement the transparent update feature. We only needed to implement appropriate interposition modules to provide transparent update support.
Evaluation
We evaluated the impact of an update to the routing module with the Surge application running on a 5-hop 21-node network in Avrora. We ran Surge on two configurations: (i) plain SOS, and (ii) SOS+H ERMES implementing the transparent update support for the routing module.
For the plain SOS configuration, the update was emulated by first removing the old module and immediately inserting an updated copy. For the configuration with H ERMES and transparent update support, the steps followed the sequence described above with the SOS process ID workaround. Each run was 1,500 seconds long, and included an update to the tree-routing module midway through the run. The results reported are averages across five such runs. From the plots in FIG. 5(A) and FIG. 5(B) , which show the average delivery latency for Surge packets from base station and a node 4 hops away respectively, it is clear that when the tree routing module is removed from the system, Surge on plain SOS sees complete disruption in packets delivered. Surge with the transparent update functionality runs with no apparent disruption, but has higher packet delivery latencies consistent with the overhead of interposition.
For this experiment, we also instrumented the SOS kernel and the Surge application to collect per-node statistics for packet drops due to the update. None are reported for the configuration with H ERMES and transparent update support, while plain Surge suffers packet losses throughout the network, ranging from 24 at the base-station, to 50 at a node 5 hops away. Losses increase for nodes farther away, consistent with the longer duration taken to rebuild routing state at those nodes.
Traffic Shaping and Rate Control
We have described how H ERMES can be used to perform various network management tasks including access control, traffic shaping, etc. In this case study, we design and evaluate an application-specific rate-control scheme using H ERMES , to illustrate this capability of our framework. We implement our rate-control scheme by interposing the application's (i.e., Surge's) communication-related I/O calls that are used to send and receive network messages. The interposition module simply enforces a variable, developer-specified upper limit by dropping packets if the current rate exceeds the limit. If the current sending rate is below the limit, the interposition module merely passes the packet through to the network interface, and the corresponding response is returned to the application. Note that while this case study is a simple illustration, H ERMES offers the flexibility for users to define more powerful protocol-aware rate-control schemes.
Evaluation
We evaluated the rate-control scheme on a network of nine MicaZ motes set in a 3×3 grid (1.5 feet apart). Besides running Surge and a TreeRouting module on each mote, we also ran a time synchronization protocol (RATS) to measure the latencies seen by packets during the experiments. One of the motes was designated to be a rogue node, and emulated a haywire Surge module that, once triggered, sent data packets at eight times the normal rate. In the base set of experiments, we ran Surge over plain SOS without H ERMES . We then ran Surge with our rate-control scheme implemented using H ERMES , with the rest of the experimental setup unchanged. Both experiments were run for 2000 seconds, with Surge sending one packet every 8 seconds.
FIG. 6 shows the number of packets received at the base station from each node, for both cases. It is easy to see that for plain Surge without rate-control, the rogue node ended up successfully sending almost three times the normal number of data packets. Due to this, nodes 2 and 3 , which were close to node 4 , were starved of bandwidth which caused the time synchronization module on them to fail, crashing the nodes in the process. As a result, nodes 2 and 3 report a much lower packet count. For Surge with the interposed rate-control scheme, each node successfully delivered approximately the same number of packets to the base station, as seen in the figure. The rate-control scheme was thus able to limit the rogue node's ability to disrupt network operation and ensure fair use of network resources.
CONCLUSION
Ensuring reliable software operation in sensor networks is a crucial problem that cannot be solved by testing in controlled environments using simulation and emulation tools alone and should be done in the real environment. Run-time visibility and control over program execution are two fundamental characteristics that will significantly ease the job of reliable software development in sensor networks. Towards this, we have proposed H ERMES , a minimally-intrusive framework based on interposition that enables visibility and control of the in-field execution of sensor systems. H ERMES is lightweight and requires no changes to the application software whose execution is to be observed or controlled. Through a prototype implementation using a popular sensor operating system and three realistic case studies, we have demonstrated the flexibility and utility of H ERMES in providing support for various operations involved in ensuring reliability in sensor systems.
Accordingly, the invention should be only limited by the scope of the claims attached hereto
TABLE 1
Surge on SOS + HERMES
Function call
SOS
Interp. off
Interp. on
ker_id
8
40
467 (Surge)
tr_get_hdr_size
6
6
112
inter_get_ker_func
N/A
19
23 (Kernel)
23
31 (Non-interposed module)
142 (Interposition module)
347 (Interposed module)
TABLE 2
Memory usage
Average packet latency
[bytes]
Packets received
[milliseconds]
OS configuration
RAM
ROM
Heap
Base Station
Surge Node
Base Station
1-hop Node
Plain SOS
100
38.248
684
124
110
0.6
28.8
SOS + HERMES
No inter. module
100
46.580
697
124
109
0.8
28.9
Inter. module present,
100
47.572
723
124
110
0.8
29.0
interposition off
Surge interposed
100
47.572
723
124
107
1.2
29.4
Surge. Tree Routing
100
47.572
723
124
109
1.3
29.8
interposed
|
A computer implemented technique framework, prototype tool and associated methods that provide a high degree of visibility and control over the in-field execution of software in a minimally intrusive manner wherein developer-defined correctness tests and validation logic are embedded into the sensor node itself, making in-field software testing autonomous without necessitating continuous developer participation.
| 7
|
TECHNICAL FIELD
[0001] This invention relates generally to a plunger lift apparatus and method that includes one or more sensors.
BACKGROUND
[0002] To produce hydrocarbons from a subterranean reservoir, one or more wellbores are drilled through the earth formation to the reservoir. Each wellbore is then completed by installing casing or liner sections and by installing production tubing, packers, and other downhole components. For certain types of wells, artificial lift systems are installed to enhance the production of hydrocarbons. One such artificial lift system includes an electrical submersible pump that pumps fluids from a downhole location in a wellbore to the well surface. Another type of artificial lift system is a gas lift system, where pressurized gas (pumped from the surface of the well or from an adjacent wellbore) is used to lift well fluids from a downhole location in the wellbore.
[0003] Yet another type of artificial lift mechanism is a plunger lift production mechanism often used to remove oil or other liquids from gas wells. Gas wells that require swabbing, soaping, blowing down, or stop cocking are candidates for plunger lift production mechanisms. A plunger lift production mechanism typically includes a relatively small cylindrical plunger that travels through tubing extending from a downhole location adjacent a producing reservoir to surface equipment located at the open end of the wellbore. In general, liquids that collect in the wellbore and inhibit the flow of gas out of the reservoir and into the wellbore are collected in the tubing. Periodically, the end of the tubing is opened at the surface and the accumulated reservoir pressure is sufficient to force the plunger up the tubing. The plunger carries with it to the surface a load of accumulated fluids that are ejected out of the top of the well to allow gas to flow more freely from the reservoir into the wellbore and to a distribution system at the well surface. After the flow of gas has again become restricted due to further accumulation of fluids downhole, a valve in the tubing at the well surface is closed so that the plunger falls back down the tubing for lifting another load of fluids to the well surface upon reopening of the valve.
[0004] In plunger lift production mechanisms, there is a requirement for the periodic operation of a motor valve at the wellhead to control the flow of fluids from the well to assist in the production of gas and liquids from the well. Conventionally, a motor valve is controlled by a timing mechanism that is programmed in accordance with principles of reservoir engineering to determine the length of time that the well should either be “shut in” (and restricted from flowing) and a time the well should be “opened” to freely produce. Generally, the criterion used for operation of the motor valve is strictly based on a pre-selected time period. In most cases, parameters such as well pressure, temperature, and so forth, are not available in conventional plunger lift production mechanisms because of the costs associated with intervention to obtain well pressure, temperature, and other information.
[0005] Operation of a motor valve based only on time is often not adequate to control outflow from the well to enhance well production. Proper setting of logic to control the plunger lift production mechanisms usually is based on trial and error, with continued evaluation needed for changing well performance that necessitates well site trips to adjust timing for the control of motor valves.
SUMMARY
[0006] In general, according to the invention, a plunger lift production mechanism includes a plunger having one or more sensors to measure well parameters to enable operation of the plunger lift production mechanism based on the measured well parameters. For example, a plunger lift apparatus includes wellhead equipment containing a receiver, a conduit extending from the wellhead equipment into a wellbore, and a plunger adapted to be run through the conduit to a downhole location in the wellbore. The plunger includes at least a sensor to measure a downhole parameter, where the plunger is adapted to communicate the measured downhole parameter to the receiver.
[0007] Other or alternative features will become apparent from the following description, from the drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 illustrates well equipment that includes a plunger lift production mechanism according to an embodiment.
[0009] FIGS. 2A-2E illustrate an example operation of the plunger lift production mechanism according to an embodiment.
[0010] FIG. 3 is a block diagram of components of a plunger and a receiver in the plunger lift production mechanism of FIG. 1 .
DETAILED DESCRIPTION
[0011] In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments are possible.
[0012] As used here, the terms “up” and “down”; “upper” and “lower”; “upwardly” and “downwardly”; “upstream” and “downstream”; “above” and “below” and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or other relationship as appropriate.
[0013] FIG. 1 illustrates equipment associated with a well that includes a plunger lift production mechanism 100 , wellhead equipment 102 , an electronic controller 104 , and a motor valve 106 . A wellbore 108 is lined with casing or liner 110 , with perforations 112 formed at a wellbore interval to enable the communication of wellbore fluids with surrounding formation. A tubing 114 extends from the wellhead equipment 102 to the wellbore interval adjacent the perforated region of the casing and formation. A tubing stop 116 is located at the bottom portion of the tubing 114 , with the tubing stop 116 including a bleed valve. Above the tubing stop 116 is a bumper spring 118 that is used for receiving a traveling plunger 120 (a plunger that travels between a downhole location and the well surface). The bumper spring 118 includes a spring that absorbs shock when the plunger 120 is dropped onto the bumper spring 118 .
[0014] The wellhead equipment 102 includes a lubricator 122 , and a master valve 124 for shutting in the wellbore during insertion of intervention equipment through the lubricator 122 . Also, a catch 126 is provided between the master valve 124 and the lubricator 122 . The catch 126 includes a receiver 128 to receive the plunger 120 . The receiver in the catch 126 provides both a physical (mechanical) and electrical connection to the plunger 120 . The electrical connection enables electrical communication (of power and signaling) over a cable 129 with the electronic controller 104 . In addition, the receiver 128 in the catch 126 has a telemetry element to enable wired or wireless communication with the plunger 120 . Wireless communications may include electromagnetic, radio frequency (RF), infrared, inductive coupler, pressure pulse, or other forms of wireless communications. RF and inductive coupler communications between the receiver 128 and plunger 120 may be most efficient.
[0015] The electronic controller 104 is connected over a link 130 to the motor valve 106 . The electronic controller 104 controls the motor valve 106 to determine when the motor valve 106 is to be opened or closed. When opened, the motor valve 106 enables flow of well fluids, such as gas, out of the wellbore through pipe 136 . Although referred to as a “motor valve,” other types of valves or flow control devices can be used in other embodiments.
[0016] In accordance with some embodiments of the invention, the plunger 120 includes one or more sensors 132 , 134 that are used for measuring characteristics associated with the wellbore and surrounding formation. As used here, the term “plunger” refers to any moveable element that is capable of traveling through at least a portion of the wellbore. The sensors 132 , 134 communicate through a telemetry element 236 with the corresponding telemetry element in the receiver 128 of the catch 126 . As noted above, such communication includes wireless or wired communications. The measured characteristics are communicated from the sensors 132 , 134 through the receiver 128 to the electronic controller 104 .
[0017] Examples of measured characteristics include pressure, temperature, other well characteristics such as fluid flow rate, fluid density, formation characteristics such as formation pressure, formation resistivity, and other downhole characteristics. More generally, the sensors measure downhole parameters. The provision of sensors 132 , 134 allows the electronic controller 104 to determine when the motor valve 106 should be opened or closed. In addition to timing criterion programmed into the electronic controller 104 , the electronic controller 104 takes into account data from the sensors 132 , 134 to control opening and closing of the motor valve 106 . The sensors 132 , 134 are powered by a power source, such as a battery.
[0018] By being able to monitor downhole environment information (information pertaining to well characteristics, formation or reservoir characteristics, and/or other downhole parameters) using the sensors 132 , 134 , the electronic controller 104 is able to automatically adjust the operation of the plunger lift production mechanism, thus eliminating manual intervention by the well operator for determining when the motor valve 106 needs to be opened or closed. Consequently, trial-and-error approaches to plunger lift control can be avoided or reduced. For example, motor valve 106 can be controlled to lift the plunger 120 or allow the plunger 120 to drop back into the wellbore in response to preset pressure thresholds as measured by the sensor 132 or 134 in the plunger 120 .
[0019] Additionally, the electronic controller 104 is configured to communicate measurement data (from the sensors 132 , 134 ) over a network 140 (wired and/or wireless network) to a remote node 142 . The electronic controller 104 is also able to communicate operational information regarding operation of the plunger lift production mechanism 100 to the remote node 140 .
[0020] Measured downhole parameters can also be communicated to the remote node 142 , or processed locally at the wellsite, to evaluate the reservoir and field associated with the wellbore. For example, the measured downhole parameters can be compared to historical information of the reservoir or surrounding reservoirs. The sensors provided in the traveling plunger 120 enable acquisition of the downhole parameters without the use of an expensive or highly sophisticated telemetry system. Integrating the sensors 132 , 134 into the plunger lift production mechanism allows well monitoring to be provided as an integral part of the relatively low cost plunger lift production mechanism without additional wellbore infrastructure. Consequently, administrative and production costs related to well production supervision can be reduced.
[0021] Alternatively, the telemetry element 236 can communicate wirelessly with the receiver 128 (as the wellhead) from a remote location, such as a remote location in the wellbore. To enable long distance wireless communication, the plunger 120 can be fitted with a larger capacity power source, such as a high-capacity battery.
[0022] In an alternative embodiment, instead of providing a sensor in the plunger, a sensor (or sensors) 135 can be positioned in a stationary location downhole in the wellbore (such as proximate the bumper string 118 ). In this alternative embodiment, the traveling plunger acts as a telemetry device to communicate the information from the downhole stationary sensor 135 to the surface receiver 128 . The traveling plunger can download information from the downhole stationary sensor 135 to a storage 133 ( FIG. 3 ) in the plunger when the plunger is positioned downhole proximate this sensor 135 . The communication between the plunger and the sensor can be wired communication or wireless communication (e.g., electromagnetic, inductive coupler, etc.). The stored information (in the storage 133 of the sensor) is carried by the plunger to the surface, where the stored information is communicated through the receiver 128 to the controller 104 .
[0023] FIGS. 2A-2E illustrate an example operation of the plunger lift production mechanism under control of the electronic controller 104 . Initially, as illustrated in FIG. 2A , the well is closed (the motor valve 106 is closed). Pressure in the wellbore builds (as a result of gas from the surrounding reservoir entering the wellbore through perforations 112 of FIG. 1 ), with a liquid column 202 building above the plunger 120 that is located at the bottom of the tubing 114 . Note that the plunger 120 is sitting on the bumper spring 118 ( FIG. 1 ).
[0024] Next, as depicted in FIG. 2B , the motor valve 106 is opened by the electronic controller 104 , which allows the built-up pressure in the wellbore to move the plunger 120 (and the liquid column 202 ) upwardly towards the wellhead equipment. The decision to open the motor valve 106 can be based on a timing criterion and/or measured downhole parameters (either parameters measured previously or in real time). As depicted in FIG. 2B , gas flow 204 is provided underneath the plunger 120 to move the plunger 120 upwardly. When the plunger 120 is received in the catch 126 ( FIG. 1 ), as depicted in FIG. 2C , the gas flow is allowed to pass by the plunger 120 and through the conduit 136 (with the motor valve 106 still open). As depicted in FIG. 2D , as liquids accumulate in the wellbore, the velocity of gas flow drops. Upon detection of the reduced gas flow, the electronic controller 104 shuts the motor valve 106 . Once the motor valve 106 is shut, the plunger 120 is allowed to drop toward the accumulated liquid column 206 at the bottom of the tubing 114 , as depicted in FIG. 2E . The plunger 120 drops to the bottom of the tubing 114 to the position depicted in FIG. 2A . The process of FIGS. 2A-2E is then repeated.
[0025] As depicted in FIG. 3 , the components of the plunger 120 and the receiver 128 are depicted in greater detail. The plunger 120 includes the sensors 132 , 134 . Note that the plunger 120 can include less than or more than the two sensors 132 , 134 depicted in FIG. 3 . The sensors 132 , 134 are powered by a power source 202 , which can be a battery, a capacitor, or a combination of a battery and capacitor. Other power sources can also be used in other embodiments. The sensors 132 , 134 are coupled to the telemetry element 236 . Also, at the upper end of the plunger 120 is a connector 204 for connection to a mating connector 206 in the receiver 128 . The connectors 204 , 206 enable electrical connection between the plunger 120 and the receiver 128 to allow wired electrical communication. Also, the electrical connection enables the receiver 128 to charge the power source 202 in the plunger 120 .
[0026] Alternatively, instead of a wired connection between connectors 204 and 206 , the telemetry element 236 is capable of wireless communications, such as electromagnetic communications, RF communications, inductively-coupled communications, infrared communications, pressure pulse communications, and so forth. The telemetry element 236 can, for example, communicate wirelessly with a telemetry element 208 in the receiver 128 . Thus, the telemetry elements 236 , 208 can be electromagnetic telemetry units (for communicating electromagnetic signals), radio frequency telemetry units (for communicating radio frequency signals), inductively coupled telemetry units, infrared telemetry units (for communicating infrared signals), or pressure pulse telemetry units (to communicate pressure pulse signals).
[0027] The telemetry element 208 is connected to an interface 210 in the receiver 128 . The interface 210 communicates over the cable 129 with the electronic controller 104 . The electronic controller 104 includes a central processing unit (CPU) 212 and an associated storage 214 . Software modules in the electronic controller 104 are executable on the CPU 212 . Such software modules 216 include software modules to receive and process measurement information from the sensors 132 , 134 . The software modules 216 also are capable of communicating with the remote node 142 ( FIG. 1 ) to communicate measurement information, as well as other operational information associated with the plunger lift production mechanism. The software modules 216 can also include software to process information gathered from the sensors 132 , 134 to monitor the performance of the wellbore as well as to control operation of the plunger lift production mechanism. For example, one such software module can be programmed with timing intervals at which the plunger mechanism should be cycled between its well surface position and downhole position, taking into account the downhole parameters measured from the sensors 132 , 134 .
[0028] The software modules 216 can also evaluate performance of the plunger lift production mechanism based on the measured downhole parameters associated with the wellbore, field, and reservoir. The cycling of the plunger 120 can be adjusted based on the evaluated performance.
[0029] The plunger 120 can also be configured to include pressurized gas that is bled off by a low power relief valve while at the well surface lubricator. When the monitored wellbore pressure crosses a predetermined threshold, the pressurized gas can be bled off to cause the plunger 120 to be able to drop back into the wellbore.
[0030] Also, maintenance of the plunger lift production mechanism can be optimized and better scheduled by enabling remote monitoring at the remote node 142 .
[0031] Instructions of such software routines or modules are stored on one or more storage devices in the corresponding systems and loaded for execution on corresponding processors. The processors include microprocessors, microcontrollers, processor modules or subsystems (including one or more microprocessors or microcontrollers), or other control or computing devices. As used here, a “controller” refers to hardware, software, or a combination thereof. A “controller” can refer to a single component or to plural components (whether software or hardware).
[0032] Data and instructions (of the software) are stored in respective storage devices, which are implemented as one or more machine-readable storage media. The storage media include different forms of memory including semiconductor memory devices such as dynamic or static random access memories (DRAMs or SRAMs), erasable and programmable read-only memories (EPROMs), electrically erasable and programmable read-only memories (EEPROMs) and flash memories; magnetic disks such as fixed, floppy and removable disks; other magnetic media including tape; and optical media such as compact disks (CDs) or digital video disks (DVDs).
[0033] While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations there from. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the invention.
|
A plunger lift apparatus includes wellhead equipment containing a receiver, a conduit extending from the wellhead equipment into a wellbore, and a plunger to be run through the conduit to a downhole location in the wellbore. The plunger includes at least a sensor to measure a downhole parameter, and a plunger is adapted to communicate the measured downhole parameter to the receiver.
| 4
|
This is a Divisional of application Ser. No. 08/362,289 filed Dec. 22, 1994, which is a Divisional of 08/175,478 filed Dec. 29, 1993 now U.S. Pat. No. 5,400,288; which is a Continuation of application Ser. No. 07/843,780 filed Feb. 28, 1992; which is a Divisional of application Ser. No. 07/512,611 filed Apr. 20, 1990 now U.S. Pat. No. 5,093,807; which is a Continuation application of Ser. No. 07/137,305 filed Dec. 23, 1987.
TECHNICAL FIELD OF THE INVENTION
The present invention relates in general to digital memory circuits. Specifically, the present invention relates to digital memory circuits which have particular advantages when used in connection with video applications.
BACKGROUND OF THE INVENTION
Digital TV, VCR, and related video applications often utilize a frame or field memory that stores pixels which together represent an entire frame of video. Such a frame memory is used in producing a variety of special effects, such as frame freezing, zoom, pan, split screen monitoring, and the like. Although a frame memory may be constructed using conventional discrete integrated circuits, such a frame memory is relatively expensive, dissipates an undesirably large amount of power, and occupies an undesirably large amount of space. When such a frame memory is targeted for use in a commercial product, these problems are major ones. Accordingly, a single integrated circuit, either alone or in combination with as few other integrated circuits as possible, improves upon a frame memory which has been constructed from conventional discrete integrated circuits.
Prior art integrated circuit devices have attempted to address the frame memory problem. However, such devices fail to provide an architecture which adequately addresses video application needs. For example, devices which include only a few of the typically needed frame memory functions may be used in providing a wide variety of special effects. However, they must be combined with such a large quantity of conventional discrete integrated circuits that little improvement results over constructing a frame memory entirely from conventional discrete integrated circuits. On the other hand, a conventional frame memory integrated circuit may include a random access memory with complete on-chip address calculation. A video application which utilizes such a frame memory accesses the entire frame memory serially. Thus, frame freeze and split screen monitoring special effects are supported. However, zoom and pan functions are either impossible or impractical using such a device.
Accordingly, the industry feels a need for a frame memory integrated circuit which optimizes circuit architecture to accommodate a wide variety of special effects without requiring a large quantity of surrounding integrated circuits.
SUMMARY OF THE INVENTION
Accordingly, it is an advantage of the present invention that a frame memory circuit is provided which permits limited random access. Consequently, a device constructed according to the teachings of the present invention may be efficiently used to perform a wide variety of special effect video applications.
Another advantage of the present invention is that a memory circuit is provided which includes a variety of address calculation modes. Thus, a portion of the address calculations for certain special effect functions may be transferred to the memory circuit, and a video application which utilizes such a memory circuit need not allocate processing power to such calculations.
The above advantages of the present invention are carried out in one form by a memory circuit which stores and provides streams of data. This memory circuit supports both serial access and random access. A data input of a random access memory array couples to a data buffer so that the data buffer may synchronize operation of the memory array with the streams of data. An address input of the random access memory array couples to an address sequencer which generates a sequence of memory addresses that are successively applied to the memory array. An address buffer register also couples to the address sequencer. The address buffer register supplies a random access address to the address sequencer to initialize the sequence of memory addresses supplied by the address sequencer.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in connection with the accompanying drawings, in which like reference numbers indicate like features throughout the drawings, and wherein:
FIG. 1 illustrates a frame of a video display screen with which the present invention may be used;
FIG. 2 shows a block diagram of a memory circuit built according to the teachings of the present invention;
FIG. 3 shows a block diagram of a first alternate embodiment of an address generator portion of a memory circuit built according to the teachings of the present invention;
FIG. 4 shows a block diagram of a second alternate embodiment of an address generator portion of a memory circuit built according to the teachings of the present invention and connected to a microprocessor to form a system; and
FIG. 5 shows a block diagram of an address sequencer utilized by the address generator portion of a memory circuit built according to the teachings of the present invention.
DETAILED DESCRIPTION
FIG. 1 illustrates a video frame 10 , such as may appear on a TV tube or other video display terminal. Although frame 10 may appear as a continuous analog video picture to a viewer, frame 10 may be electrically represented as a multiplicity of digitized pixels 12 . Each one of the pixels 12 defines parameters, such as color and relative intensity, for one of a multiplicity of very small dot areas within the picture of frame 10 . Accordingly, the video frame 10 may contain a relatively large number of the digitized pixels 12 . For example, a frame containing 488 columns of pixels 12 by 488 rows of pixels 12 has a total of 238,144 pixels per frame.
Pixels 12 are typically transmitted or otherwise processed in a predetermined sequential order to preserve the spatial relationships between the pixels 12 . For example, in a conventional raster scan application, pixels 12 may be transmitted to a memory device for storage or from storage in a memory device to a video display in successive order beginning with a pixel 12 a , that represents the pixel 12 in the first column of the first row of frame 10 , and continuing in successive order to a pixel 12 b , which represents the pixel 12 in the last column of the first row of frame 10 . Immediately following the transmission of pixel 12 b and sync information (not shown), a pixel 12 c , which represents the pixel 12 in the first column of the second row, may be transmitted followed in successive order by the remaining pixels 12 contained in the second row of frame 10 . Transmission of pixels 12 continues in this fashion until a pixel 12 d , which represents the pixel 12 in the last column of the last row of frame 10 , has been transmitted. Thus, any processing device which knows the timing relationship between an arbitrarily located pixel 12 and the beginning pixel 12 a also knows or can easily calculate the spatial location of such arbitrarily located pixel 12 within frame 10 .
A digital TV, VCR, or the like may contain a large frame or field memory which is capable of storing all of the pixels 12 within frame 10 . Pixels 12 collectively appear as a serial data stream when they are applied to the frame memory. Except for special effects, the relative order of pixels 12 in this serial data stream must generally be preserved when they are read from the frame memory to preserve the spatial relationships between the pixels 12 . Some special effects do not require this preserved order, and valuable computation time may be wasted by precisely preserving the order of the pixels 12 as the pixels 12 are being read from the frame memory.
One such special effect is a zoom effect wherein a small portion of a stored, digitized frame is expanded and converted to an analog signal to fill an entire video display. For example, if frame 10 in FIG. 1 represents an entire video display, then an area 11 within frame 10 bounded by rows i and j and columns m and n is expanded in a zoom special effect to fill the entire frame 10 . Thus, in the zoom special effect all of the digitized pixels 12 residing within frame 10 outside of the area 11 bounded by rows i and j and columns m and n are inactive and may be discarded. In other words, these inactive ones of the pixels 12 need not be read from the frame memory. Consequently, the pixel 12 located at column m and row i will be utilized as the first active pixel 12 a transmitted to the video display in the zoom special effect. Active pixels 12 may be duplicated to complete an entire row of frame 10 , and rows may be duplicated to complete the vertical component of the zoom effect. All of the digitized pixels transmitted to the video screen are converted to an analog signal for display on the video screen.
In a split screen special effect, an entire frame 10 may be shrunk into a small area 13 of a screen, such as that bounded by row j and the last row of frame 10 , and column n and the last column of frame 10 . This special effect is accomplished by utilizing only active ones of the pixels 12 out of each of a predetermined number of the pixels 12 from an entire frame 10 of the pixels 12 , and ignoring the intervening inactive ones of the pixels 12 (ie. skipping inactive pixels). For the example depicted in FIG. 1, the shrunken frame is formed using only the active pixels 12 that reside in one of every three columns and one of every three rows of the frame 10 .
The present invention provides a memory circuit which series as a frame memory and permits these and other special effects to be performed efficiently. FIG. 2 shows a block diagram of a memory circuit 14 built according to the teachings of the present invention. In general, the preferred embodiment of memory circuit 14 represents a single chip integrated circuit that contains 2 20 or 1,048,576 bits of memory storage organized as 262,144 four bit wide words with special write and read access arrangements. Accordingly, a sufficient quantity of word storage is provided to buffer or store an entire 488×488 frame of the pixels 12 (see FIG. 1 ). If more than four bits of precision are required to accurately describe each pixel, then additional ones of memory circuit 14 may be used to store such additional bits.
Memory circuit 14 generally operates in a serial access mode for both write and read operations but has particular features which permit random access for writing or reading of the memory circuit 14 on a limited scale. those skilled in the art will understand that serial access refers to a mode of storing and reading data in which the data must be read out from a memory in the same order sequential address in which it was stored into the memory. Furthermore, random access refers to the ability to write, read, or otherwise access any location in a memory array by supplying a selected unique address which corresponds to such memory location.
Specifically, for receiving analog video signals converted to digital pixels, memory circuit 14 includes a serial pixel data input 16 a , which in the preferred embodiment supplies four bits of data per pixel. Serial pixel data input 16 a couples to an input port of a write serial latch 18 a , and an output port of write serial latch 18 a couples to an input port of a write register 20 a . An output port of write register 20 a couples to a data input port 22 a of a memory array 24 . In the preferred embodiment, memory array 24 is a dynamic random access memory (DRAM) array containing 2 18 or 262,144 four bit memory locations. A data output port 22 b of memory array 24 couples to a data input port of a read register 20 b , and a data output port of read register 20 b couples to a data input port of a read serial latch 18 b . A data output port of read serial latch 18 b couples to a serial pixel data output 16 b , which in the preferred embodiment provides four bits of data per pixel for conversion to an analog video signal for display.
A serial write clock terminal 26 a couples to a write address generator 28 a , an arbitration and control circuit 30 , and a clock input of write serial latch 18 a . Similarly, a serial read clock terminal 26 b couples to a read address generator 28 b , arbitration and control circuit 30 , and a clock input of read serial latch 18 b . A refresh address and timing circuit 32 has an output which couples to an input of arbitration and control circuit 30 , and outputs 21 a , 21 b , 23 , and 25 from arbitration and control circuit 30 respectively couple to a clock input of write register 20 a , a clock input of read register 20 b , a control input of memory array 24 , and an address input of memory array 24 .
Serial write clock terminal 26 a and serial read clock terminal 26 b receive respective write and read continuous clock signals each formed of rising and falling edges regularly spaced in time. The write and read clock signals are continuous during operation of memory circuit 14 .
As shown in FIG. 2, address generators 28 a and 28 b comprise respective write and read address ports that are structurally similar to one another in the preferred embodiment. Thus, a write control data terminal 34 a couples to a serial data input of an address buffer register 36 a in write address generator 28 a . A read control data terminal 34 b couples to a serial data input of an address buffer register 36 b in read address generator 23 b . likewise, a write control strobe terminal 38 a couples to a clock input of address buffer register 36 a , and a read control strobe terminal 38 b couples to a clock input of address buffer register 36 b . A data output of address buffer register 36 a couples to a data input of an address sequencer 40 a , and a data output of address buffer register 36 b couples to a data input of an address sequencer 40 b . A write reset terminal 42 a couples to a clear input of address sequencer 40 a , and a write transfer terminal 44 a couples to a preset input of address sequencer 40 a . A read reset terminal 42 b couples to a clear input of address sequencer 40 b , and a read transfer terminal 44 b couples to a preset input of address sequencer 40 b . Serial write clock terminal 26 a couples to a clock input of address sequencer 40 a within address generator 28 a , and serial read clock terminal 26 b couples to a clock input of address sequencer 40 b within address generator 28 b . An output 46 a of address sequencer 40 a presents the output signal from address generator 28 a and couples to an input of arbitration and control circuit 30 . Likewise, an output 46 b of address sequencer 40 b presents the output signal from address generator 20 b and couples to arbitration and control circuit 30 . Memory circuit 14 may be provided in a 20 pin integrated circuit package.
As discussed above, memory circuit 14 may be operated in either a serial or a limited random access mode. In addition, the storing or writing of data into memory circuit 14 may occur asynchronously with the reading or providing of data from memory circuit 14 . Asynchronous means timed by other than a common clock. Memory circuit 14 may be written into serially by activating write reset signal on terminal 42 a to clear address sequencer 40 a . Then, a four bit wide stream of serial data may be stored in memory circuit 14 by applying the four bit data nibbles at the write clock rate to the data input 16 a while asserting a serial write clock signal at terminal 26 a . One assertion of the serial write clock signal causes write serial latch 18 a to temporarily store or buffer one four bit data nibble. Write serial latch 18 a operates as a four bit wide shift register. Thus, subsequent four bit nibbles from the data stream of serial pixel data applied at data input 16 a are shifted into serial latch 18 a at the write clock rate upon subsequent assertions of the serial write clock signal.
In addition, each assertion of the serial write clock signal also causes address sequencer 40 a of write address generator 28 a to supply a new selected random access address to arbitration and control circuit 30 . In other words, address sequencer 40 a provides a stream of addresses to arbitration and control circuit 30 which corresponds to the stream of data being stored in write serial latch 18 a.
Arbitration and control circuit 30 receives addresses from address generators 28 a - 28 b and refresh address and timing circuit 32 . Circuit 30 monitors these inputs and various timing signals to decide which of the addresses provided on these inputs should be transferred at a specific time to memory array 24 . Arbitration and control circuit 30 includes conventional logic circuits for controlling the timing operation of the dynamic memories which comprise memory array 24 . Thus, arbitration and control circuit 30 passes an address generated by address generator 28 a to memory array 24 so that data may be written into memory array 24 , but a delay may occur due to refresh operations or read accesses of memory array 24 . Accordingly, arbitration and control circuit 30 may additionally contain storage devices so that addresses generated by address generators 28 a - 28 b are not lost when immediate access to memory array 24 is blocked. When arbitration and control circuit 30 identifies a time at which the serial pixel data may be written into memory array 24 , such data is transferred from write serial latch 18 a into write register 20 a and then written into memory array 24 . Accordingly, write serial latch 18 a and write register 20 a together represent a double buffering scheme which permits asynchronous operation of memory array 24 and particularly the storing of serial pixel data into memory circuit 14 .
The reading of data from memory array 24 occurs in a manner similar to that described above for the storing of data into memory array 24 . Thus, an address generated by address generator 28 b is transferred through arbitration and control circuit 30 at an appropriate time to cause data from memory array 24 to be read into read register 20 b . Thereafter, this data is transferred into read serial latch 18 b so that such data may be provided at data output terminal 16 b through the application of a serial read clock signal at terminal 26 b . Serial data is provided at output 16 b asynchronously with the operation of memory array 24 and asynchronously with the storing of serial pixel data into memory circuit 14 at terminal 16 a.
The limited random access feature of memory circuit 14 is provided through address generators 28 a - 28 b . In the embodiment of memory circuit 14 shown in FIG. 2, write address generator 28 a and read address generator 28 b are structurally and operationally identical, except that write address generator 28 a provides write addresses while read address generator 28 b provides read addresses. Accordingly, both address generators 28 a - 28 b are described below by reference only to write address generator 28 a . Those skilled in the art will recognize that read address generator 28 b operates identically in the preferred embodiment.
A random access address may be serially loaded into address buffer register 36 a by applying such address to control data terminal 34 a in a sequential manner and activating a control strobe signal applied at terminal 38 a when valid data appear at terminal 34 a . Thus, in the embodiment shown in FIG. 2, address buffer register 36 a represents a serial shift register. The use of a serial shift register conserves the number of external pins needed for constructing memory circuit 14 in an integrated circuit when compared to a parallel loaded register. After the random access address has been entered into address buffer register 36 a , it may be transferred to address sequencer 40 a by the application of a write transfer signal at terminal 44 a . In the preferred embodiments of the present invention, address sequencer 40 a may represent a presetable, binary counter or other presetable sequencing circuit. Thus, the transferred address forms the initial address of a sequence of addresses which are subsequently generated by address generator 28 a . If address sequencer 40 a represents a binary counter, then subsequent addresses will increment or decrement starting with this preset or initial value.
If memory array 24 contains 2 18 four bit words of memory, then address buffer register 36 a may advantageously represent an 18 bit register, and address sequencer 40 a may represent an 18 bit counter, or other sequencing circuit. On the other hand, address buffer register 36 a and address sequencer 40 a may contain fewer bits, such as nine bits for example. In the nine bit situation, the random access address provided by address buffer register 36 a could access the beginning of memory pages or rows wherein each page or row contains 2 9 or 512 words of memory.
The inclusion of address buffer register 36 a to provide a limited random access feature permits memory circuit 14 to be efficiently utilized in a zoom special effect. For example, a zoom effect may be accomplished by writing an entire frame of pixel data into memory array 24 using a serial write access mode. A beginning, present or initial pixel address, such as the address of a pixel located at row i column m, in FIG. 1, may then be loaded into read address buffer register 36 b and transferred to address sequencer 40 b . A first row, such as row i, of the portion of frame 10 which is to be expanded into an entire frame may then be read from memory array 24 in a serial or sequential mode until a pixel corresponding to, for example, row i, column n appears at output terminal 16 b . Readout occurs at the serial read clock rate. A row may be repeated as often as necessary to achieve vertical zoom by transferring the random access address from address buffer register 36 b to address sequencer 40 b . An address corresponding to the pixel located at row i+1 and column m may then be loaded into address buffer register 36 b and transferred to address sequencer 40 b . This process continues at the serial read clock rate until a final pixel for the frame to be expanded has been output from memory array 24 . The pixels are converted to analog video signals for display. Due to this feature, a video system need not start accesses of memory circuit 12 at an initial address, such as pixel 12 a (shown in FIG. 1) and access inactive pixels stored within memory array 24 . More efficient operation results.
The present invention contemplates alternate embodiments of address generators 28 a - 28 b . A first alternate embodiment of address generators 28 a - 28 b is shown in FIG. 3 . FIG. 3 shows only one of address generators 28 . The address generator 28 shown in FIG. 3 may serve as either write address generator 28 a or read address generator 28 b (see FIG. 2 ).
In this first alternate embodiment of an address generator 28 , address buffer register 36 may be loaded both serially and in parallel. Thus, control data terminal 34 , which may represent either write control data terminal 34 a or read control data terminal 34 b , as discussed above in connection with FIG. 2, couples to the serial data input of address buffer register 36 . Control strobe terminal 38 couples to the serial clock input of address buffer register 36 and a serial clock input of an address offset register 48 . The parallel data output of address buffer register 36 couples to a first input of an adder 50 and the data input of address sequencer 40 . A parallel data output of address offset register 46 couples to a second input of adder 50 . An output of adder 50 couples to a parallel data input of address buffer register 36 , and transfer terminal 44 couples to a parallel clock input of address buffer 36 and the preset input of address sequencer 40 . A most significant bit from the parallel data output or a serial output bit, of address buffer register 36 couples to a serial data input of address offset register 48 . Serial clock terminal 26 couples to the clock input of address sequencer 40 , and reset terminal 42 couples to a clear input of address sequencer 40 . A data output of address sequencer 40 couples to address generator output 46 .
Address buffer register 36 and address sequencer 40 operate in this first alternate embodiment similarly to their above-described operation in connection with address generator 28 a - 28 b of FIG. 2 . However, in this first alternate embodiment, the control data provided at terminal 34 is used to load both address buffer register 36 and address offset register 48 . Thus, additional bits of control data are loaded into memory circuit 14 without requiring additional integrated circuit pins. Moreover, a most significant bit, or a serial output bit 51 , from address offset register 48 may advantageously be routed to the control data input for the other one of read and write address generators 28 a and 28 b (see FIG. 1 ). In addition, the control strobe signal applied at terminal 38 may be routed to the other one of control strobe terminals 38 a and 38 b of FIG. 2 . These two connections between address generators 28 a and 28 b eliminate two integrated circuit pins from the structure shown in FIG. 2 .
In this first alternate embodiment of the present invention, the control data contained in address offset register 48 is added to a current initial address value contained in address buffer register 36 to provide a new initializing random access address value. This new initializing value is loaded into address buffer register 36 when the current address value is transferred into address sequencer 40 .
Referring additionally to FIG. 1, the first alternate embodiment of the present invention may be advantageous in performing, for example, the zoom special effect. Thus, the address offset value loaded into address offset register 48 may represent the quantity of inactive pixels occurring between column n of one row and column m of the next row. At the end of each frame row a transfer signal may be asserted on terminal 44 , and the random access address of the next active pixel, corresponding to column n of the next row, is automatically calculated and stored in address buffer register 36 to initiate another sequence of sequential accesses to memory circuit 14 . Complexity of a video system employing memory circuit 14 decreases because components external to memory circuit 14 need not calculate this address.
A second alternate embodiment of address generators 28 a - 28 b from FIG. 2 is shown in FIG. 4 . The FIG. 4 embodiment illustrates that random access addresses may be loaded into address buffer register 36 in a parallel fashion, which may be more compatible with conventional microprocessor integrated circuits. However, the number of integrated circuit pins needed to implement this embodiment increases over the embodiments discussed above in connection with FIGS. 2 and 3. In addition, FIG. 4 shows the inclusion of an alternate address buffer register 52 in addition to address buffer register 36 . Specifically, control data terminals 34 may advantageously provide an eight bit microprocessor data bus 80 which couples to data inputs of individual eight bit portions 54 a , 54 b , and 54 c of address buffer register 36 . In addition, control data terminals 34 couple to data inputs of individual eight bit portions 56 a , 56 b , and 56 c of alternate address buffer register 52 . Data outputs of individual portions 54 a - 54 c together form a 24 bit bus which couples to a first data input of a multiplexer 58 . Likewise, data outputs of individual portions 56 a - 56 c form a 24 bit bus which couples to a second data input of multiplexer 58 . A data output of multiplexer 58 couples to a data input of a binary counter which serves as address sequencer 40 in this second alternate embodiment. Of course, those skilled in the art will recognize that the number of subregisters included within address buffer register 36 and alternate address buffer register 52 and the number of bits contained within the buses described above are subject to a substantial variation in accordance with specific application requirements.
In addition, microprocessor address input terminals 60 a , 60 b , and 60 c , couple to address inputs of a decoder 62 and an address input terminal 60 d couples to an enable input of decoder 62 . The control strobe terminal 38 , discussed above, couples to an enable input of decoder 62 . Outputs 01 - 06 of decoder 62 couple to clock inputs of individual address buffer register portions 54 a - 54 c and clock inputs of individual alternate address buffer register portions 56 a - 56 c , respectively. An output 07 from decoder 62 couples to a clock input of a flip flop 64 which is configured to toggle upon the activation of the clock input. An output of flip flop 64 couples to a select input of multiplexer 58 . An output 08 of decoder 62 couples to a preset input of binary counter 40 . The serial clock 26 couples to a clock input of binary counter 40 , and reset terminal 42 couples to a clear input of flip flop 64 and a clear input of binary counter 40 . An output of binary counter 40 couples to output 46 of address generator 28 .
In this second alternate embodiment of address generator 28 , one initializing random access address may be stored in address register 36 while an alternate initializing random access address is stored in alternate address buffer register 52 . A microprocessor 82 may store these addresses in memory circuit 14 through conventional memory or I/O write operations to addresses specified by signals applied on terminals 60 a - 60 c . An address input bit applied at terminal 60 d may advantageously distinguish between a write address generator 28 a and a read address generator 28 b (see FIG. 1 ). By applying an active signal to reset terminal 42 , flip flop 64 and binary counter 40 may be initialized to a cleared state. At this point, address generator 28 operates substantially as described above in connection with FIG. 2 . However, an alternate random access address stored in alternate address buffer 52 may selectively initialize binary counter 40 . A microprocessor write operation which toggles flip flop 54 , followed by a microprocessor write operation that transfers data into binary counter 40 , initializes binary counter 40 with an alternate random access address. Flip flop 64 may be toggled by performing a write operation to the address which activates output 07 of decoder 62 . A transfer operation from the selected one of address buffer registers 36 and 52 occurs by writing to the address which activates the output 08 of decoder 62 .
Alternate address buffer register 52 may advantageously be used by a video system to efficiently buffer a line within a frame of data. Since memory circuit 14 of the preferred embodiment contains a sufficient quantity of memory to accommodate 2 18 or 262,144 pixels, memory circuit 14 has unused memory locations when used to store a single frame of data which contains, for example, 480 pixel columns by 480 pixel rows. Accordingly, a random access address in this unused portion of memory may be loaded in alternate address buffer register 52 . A single line of a frame may be efficiently stored in memory circuit 14 by transferring this alternate initial address value to binary counter 40 , then sequentially storing such line of pixels into the otherwise unused portion of memory circuit 14 .
In addition, the present invention contemplates alternative embodiments for address sequencer 40 . As shown in FIG. 4, address sequencer 40 may represent a conventional presetable, clearable, binary counter. Such circuits are well known to those skilled in the art and need not be described in detail herein. However, address sequencer 40 may alternatively represent a circuit which increments or decrements by a variable step value which may differ from the value of one. Such a circuit is shown in FIG. 5 .
Accordingly, in FIG. 5 parallel address data input terminals 44 couple to a first input of an address buffer register 66 . Preset terminal couples to a select input of address buffer register 66 . An output 67 of register 66 couples to a data input of address sequencer 68 , and the clock input terminal 26 of address sequencer 40 couples to a clock input of sequencer 68 . Likewise, the reset or clear terminal 42 couples to a clear input of register 68 . A data output of register 68 provides the data output of address sequencer 40 and additionally couples to a first input of an adder 70 . An output of adder 70 couples to a second input of address buffer register 66 . The address or control data terminals 34 , discussed above in connection with FIGS. 2-4, also couple to a data input of an address increment register 72 . Additionally, the control strobe terminal 38 , discussed above in connection with FIGS. 2-4, couples to a clock input of register 72 . A data output of an address increment register 72 couples to a second input of adder 70 .
In this FIG. 5 embodiment of address sequencer 40 , register 72 may represent either a parallel or a serially loaded register, as discussed above in connection with FIGS. 2-4. Additionally, if register 72 represents a serially loaded register, then register 72 may represent one register out of many coupled together in a long chain of serially loaded registers, as discussed above in connection with FIG. 3 . The data loaded into register 72 is intended to represent a increment step by which address sequencer 68 generates successive addresses at output 46 of address generator 28 . A current output of address sequencer 68 is added to the step increment value from address increment register 72 in adder 70 , and routed through buffer register 66 back to sequencer 68 . Thus, a subsequent address generated by address sequencer 68 equals the previous address plus the address step increment contained in register 72 . This address step increment need not equal the value of integer one but may equal any positive or negative value. Furthermore, if the number of bits carried on the buses that couple together register 72 , adder 70 , register 66 , and sequencer 68 is greater than the number of bits provided at the output of address sequencer 68 , then subsequent addresses may be incremented in fractional steps.
Address sequencer 68 may be preset, or initialized, with a random access address by applying an active signal on the preset terminal 44 , supplying data at the data control input terminals 34 , and clocking the clock signal of address sequencer 68 . Thus, this initializing random access address is loaded directly into sequencer 68 . In addition, address sequencer 68 may be cleared, or reset, by applying a reset signal to the clear input terminal 42 .
Referring additionally to FIG. 1, the address sequencer 68 depicted in FIG. 5 is useful in performing the split screen special effect where an entire frame is displayed in only a small portion of a video screen, such as the lower right hand area 13 shown in FIG. 1 . With this special effect, if memory circuit 14 has every pixel 12 of a frame 10 stored therein, then only one out of every group of a predetermined number of stored pixels is active in constructing the shrunken screen. Address sequencer 68 shown in FIG. 5 allows memory circuit 14 to provide only the active pixels by supplying a sequence of addresses which omits inactive pixel addresses.
In summary, the present invention provides a memory circuit which allows a video system to efficiently perform special effects. Specifically, the inclusion of various limited random accessing features allows memory circuit 14 to store and/or provide only active pixels for a given special effect and not inactive pixels. Consequently, active pixels may be retrieved from memory circuit 14 much quicker than occurs with the use of prior art frame memory circuits.
The foregoing description uses preferred embodiments to illustrate the present invention. However, those skilled in the art will recognize that changes and modifications may be made in these embodiments without departing from the scope of the present invention. For example, read address generator 28 b need not precisely resemble write address generator 28 a . Additionally, although the embodiments depicted in FIGS. 3-5 are mentioned above as being alternative embodiments, nothing prevents one skilled in the art from combining the teachings from more than one of these alternate embodiments into a single frame memory circuit 14 . Moreover, those skilled in the art will recognize that additional address processing capabilities may be built into frame memory circuit 14 . Such additional address processing capabilities may include the addition of a signal which indicates the end of a frame line, a signal which indicates the end of a frame, and the automatic transferring of random access addresses to an address sequencer upon the occurrence of the end of line and end of frame signals. Furthermore, although specific frame and memory array dimensions have been presented herein to aid in teaching the present invention, it is intended that the present invention not be limited to any particular dimensions. These and other modifications obvious to those skilled in the art are intended to be included within the scope of the present invention.
|
A memory circuit ( 14 ) having features specifically adapted to permit the memory circuit ( 14 ) to serve as a video frame memory is disclosed. The memory circuit ( 14 ) contains a dynamic random access memory array ( 24 ) with buffers ( 18, 20 ) on input and output data ports ( 22 ) thereof to permit asynchronious read, write and refresh accesses to the memory array ( 24 ). The memory circuit ( 14 ) is accessed both serially and randomly. An address generator ( 28 ) contains an address buffer register ( 36 ) which stores a random access address and an address sequencer ( 40 ) which provides a stream of addresses to the memory array ( 24 ). An initial address for the stream of addresses is the random access address stored in the address buffer register ( 36 ).
| 6
|
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of allowed U.S. application Ser. No. 09/002,550 to Lapointe, filed Jan. 2, 1998, for which the issue fee has been paid, now U.S. Pat. No. 6,126,578 entitled JUMPING DEVICE HAVING A FLEXIBLE TETHER AND METHOD OF USING THE JUMPING DEVICE, the entire disclosure of which is fully incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of The Invention
This invention is in the field of jumping devices for the purposes of amusement and exercise. More specifically, this invention relates to a jumping device of the type including interaction with a user's hands and feet and having a high rebound platform and a flexible tether that can be grasped by a user. By such a device, a user can bounce indefinitely on the high rebound platform while maintaining the platform against the user's feet by way of the flexible tether.
2. Description of the Related Art
Jumping devices for amusement and exercise are well known. Perhaps the most common jumping device is the pogo stick. Conventional pogo sticks typically have a telescoping design that includes a tubular frame from which a spring-actuated plunger member extends downward and terminates in a tip that contacts the ground during use of the pogo stick. Transverse footrests are formed near the lower end of the frame to allow a user of the pogo stick to mount the pogo stick and compress a spring of the plunger by applying a downward force. A typical pogo stick is disclosed in U.S. Pat. No. 2,712,443, issued to H. H. Hohberger.
Conventional pogo sticks have several limitations. Conventional pogo sticks require several moving parts that increase manufacturing costs and reduce durability. Also, the use of a spring that is compressed by the telescoping action of the frame and the plunger member requires that the frame and the plunger member be rigid enough to transmit compressive force to the spring. The use of typical rigid materials (e.g., a rigid metal such as steel) increases the risk of injury to the user of the pogo stick if the user should fall and be struck with the pogo stick. In addition, the rigid materials cause conventional pogo sticks to generate significant noise during operation which makes conventional pogo sticks less amenable to quiet indoor use.
Moreover, conventional pogo sticks are typically designed with plunger member tips and footrests that have small surface areas relative to the surface area of the user's feet. This makes conventional pogo sticks unstable during mounting and operation of the pogo stick and requires that users have a fairly high degree of balancing skills in order to operate the pogo stick. Furthermore, the unstable nature of conventional pogo sticks limits the range of maneuvers that can be performed on conventional pogo sticks and makes conventional pogo sticks difficult to abandon during a fall.
Other less complicated devices have been developed having other spring means instead of such noisy mechanical springs. For example, in U.S. Pat. No. 3,627,314, issued to Brown, a pogo stick is described utilizing an inflatable ball having a platform surface and mounted to a stick handle. Although such a device eliminates some disadvantages, it is still relatively unstable, requires a fairly high degree of balance to operate, and has limited maneuverability.
SUMMARY OF THE INVENTION
The present invention provides an improved jumping device that has minimal moving and rigid parts and a wide, stable jumping platform that provides more balancing time before jumping and allows a user to safely and quietly perform a range of jumping maneuvers. Also, folding the flexible tether facilitates convenient storage of the jumping device.
In one aspect, the present invention relates to a jumping device having a high rebound platform, a flexible tether attached to the platform, and a handle located on the tether.
In another aspect, the present invention relates to a method of jumping, including the step of providing a jumping device having a high rebound platform, a flexible tether attached at a first end to the platform, and a handle on the tether, the step of mounting the jumping device by placing a user's foot (or both feet) on the platform, grabbing the handle, then pulling the handle away from the platform, and jumping so that the platform alternates between compressed and uncompressed states.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a jumping device according to the present invention.
FIG. 2 is a front view of a platform and a lower portion of a tether of the jumping device shown in FIG. 1 .
FIG. 3 is a rear view of the platform and a lower portion of the tether of the jumping device shown in FIG. 1
FIG. 4 is a fragmentary view of the platform and a lower portion of the tether of the jumping device shown in FIG. 1 with a portion of the platform removed so as to show a rod for fastening the tether to the platform.
FIG. 5 is a perspective view of a handle and an upper portion of the tether of the jumping device shown in FIG. 1 .
FIG. 6 is a side view of an alternative high rebound platform formed as a bladder structure.
FIG. 7 is a perspective view of a jumping device according to a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1-5 show a jumping device 10 in accordance with a first embodiment of the present invention. Device 10 includes a high rebound platform 12 , a tether 14 attached to the platform 12 , and a handle 16 provided at an end of the tether 14 .
High rebound platform 12 is formed so that platform 12 can be made to alternate between a compressed state and an uncompressed state. Generally, when a body elastically compresses due to the application of compressive forces, potential energy is stored in the deformed body. The transition of the body from a compressed state to an uncompressed state results in the conversion of potential energy to kinetic energy. A high rebound platform 12 in accordance with the present invention is a structure that can be made to elastically compress between a user's feet (which contact a foot support surface 18 located on the top of platform 12 ) and the ground or other rigid surface (which contacts an impact surface 20 located on the bottom of platform 12 ) by having at least a portion of the foot support surface 18 and at least a portion of impact surface 20 move closer to one another so that kinetic energy provided during the transition of the structure from a compressed state to an uncompressed state is sufficient to create a rebound force that assists the user in jumping. A high rebound platform 12 can be characterized by the basic ability to support a user to permit jumping without bottoming out and to provide some amount of energy to assist the user in jumping. It is envisioned that jumping device 10 can be designed to operate for a particular range of user weights. Therefore, high rebound platform 12 may be adapted to elastically compress and provide rebound force for the particular range of user weights for which the device 10 is designed. It is also envisioned that a product feature, shape of a component, color code, or other labeling scheme could be used to convey easily the range of user weights appropriate for a particular jumping device 10 .
High rebound platform 12 is preferably formed from any one of a number of conventional solid, closed cell, or open cell materials that are commonly used to absorb impact or provide rebound. More specifically, platform 12 can be formed from rubbers including but not limited to natural foam rubber, natural butyl rubber (NBR), natural rubber (NR), thermoplastic rubber (TPR), and plastics including but not limited to polyethylene (PE), polyurethane (PU), and ethyl vinyl acetate (EVA). Generally, for a given high rebound material having a given contact surface area, the thicker (measured from foot support surface 18 to impact surface 20 of platform 12 ) platform 12 is, the greater the range of user weights over which the platform 12 will elastically compress and provide a rebound force. It is also understood that with different high rebound materials and different contact surface areas various weight ranges can accommodated.
FIGS. 1-4 show platform 12 formed from a plurality of layers 30 , wherein the layers are attached to one another using conventional adhesives. Other conventional lamination techniques can be used instead. Preferred high rebound materials includes but are not limited to Zoatfoam EV-50 EVA foam from Zoatfoam Inc. of Hacketstown, N. J.; foam model MC3800S with EVA from Sentinal Co.; foam model 5A with EVA from Voltek; and foam product commercially available under the tradename Metalocene from E. I. Dupont de Nemours and Co., Wilmington, Del. As shown, each layer is preferably shaped so that when stacked, the layers 30 form a complete, shaped platform 12 . The layers 30 can be shaped by use of conventional die-cut techniques, for example. The layers 30 may be shaped for functional or aesthetic reasons, and each layer may be the same or different as the others. The top and bottom layers, in particular, may also be shaped in the thickness direction so as to provide any desired surface features. For example, the foot support surface 18 or the impact surface 20 may be rounded, or may be patterned to enhance gripping of the surface(s) with a user's foot (or feet) or the floor. Such a pattern may be for anti-slip properties, or to permit use on wet surfaces or other materials (e.g., grass lawns, concrete, etc.) that my otherwise affect the material (e.g., by abrasion or puncture). Moreover, each of the layers 30 may be made of the same or different material. For example, the bottom layer may be of a tougher material to enhance its durability for particular surfaces like concrete. For use in homes, a softer (non-scratch) material may be desirable. Along these same lines, coatings or other surface treatments are also contemplated. Surface treatments include the provision of sheet material to cover all or a portion of the impact surface 20 , for example. A non-slip material may be desirable for rendering the device more suitable for use on certain surface such as finished wood.
Alternatively, platform 12 can be formed as a single piece of rebound material. Like the laminated platform described above, a single block platform 12 can be shaped, coated or treated to have certain properties or for aesthetic reasons depending on an intended usage of the device 10 . Moreover, even with a single layer construction, more than one distinct material portions thereof can be made by conventional techniques used in the making of the material, e.g., using coextrusion techniques. It is believed that for conventional rubbers and plastics, high rebound platform 12 , whether formed from single or multiple layers, should have a thickness in the range of about 1 inch to about 12 inches and preferably has a thickness of about 4.5 inches for an average user.
Alternatively, as shown in FIG. 6, a high rebound platform 12 ′ may be constructed from materials without relying on a rebound characteristic of the material itself, as is the case with a foam layer or foam layers. A resilient material may be shaped to form a bladder 30 ′ (that may be similar to or different from the layered platform 12 of FIG. 1) and filled with a fluid 31 ′. Then, bladder 30 ′ can be compressed between a user's feet (which contact a foot support surface 18 ′ located on the top of platform 12 ′) and the ground or other rigid surface (which contacts an impact surface 20 ′ located on the bottom of platform 12 ′) so that the fluid 31 ′ (such as air) is compressed or bladder 30 ′ is caused to expand, or both, to store potential energy and so that kinetic energy provided during the transition of the structure from a compressed state to an uncompressed state is sufficient to create a rebound force that assists the user in jumping.
Again referring to FIGS. 1-5, foot support surface 18 and impact surface 20 of platform 12 are advantageously shaped to allow a user of the device 10 more easily to maintain balance while operating the device 10 . It is believed that platform 12 should have a depth (measured from a front face 22 to a back face 24 of platform 12 ) of at least about 2 inches and preferably has a depth in the range of about 4 inches to about 8 inches for an average user. It is also believed that platform 12 should have a width (measured from a first lateral side 26 to a second lateral side 28 ) of at least about 6 inches and preferably has a width of about 12 inches for an average user. In FIGS. 1-4, foot support surface 18 and impact surface 20 have the same shape, though, as above, foot support surface 18 and impact surface 20 could have shapes that differ from one another.
FIGS. 1-5 show a tether 14 formed preferably as a loop of flexible (i.e., non-rigid) cord having two straigtenable portions 32 and 34 that are attached to the platform 12 . As shown in FIG. 4, ends 36 and 38 of portions 32 and 34 , respectively, can be connected to a rigid rod 40 (preferably formed from bamboo because it is rigid and lightweight) that is located within the layers 30 of platform 12 . The ends 36 and 38 may be formed as loops that surround and connect to rod 40 . An opening 42 can be formed in one or more of the layers of platform 12 so as to allow portions 32 and 34 of tether 14 to pass through foot support surface 18 of platform 12 and attach to rod 40 . Other ways of connecting the tether portions 32 and 34 to the platform 12 are also contemplated. For example, the portions 32 and 34 can be passed through opening(s) of platform 12 all the way though and be tied to together at the impact surface 20 in which recesses can be formed to accommodate the tied portions 32 and 34 so as to provide a substantially flat, stable impact surface 20 . Likewise, the rod 40 may be provided at any location within the thickness of the platform 12 (e.g., between any two layers 30 ) and may be of any effective shape (e.g., a plate-like element to which ends 36 and 38 are attached). Also, recesses may be formed in the layers 30 so as to accommodate the rod 40 and provide substantially flat foot support and impact surfaces 18 and 20 .
Tether 14 is preferably significantly extendible and formed from an elastic material such as a textile-covered elastic cord or an extruded elastic tubing without a cover. Suitable tubing includes natural latex rubber tubing, commonly known as surgical tubing, because it is highly extendible. Alternatively, tether 14 can be formed from conventional non-elastic ropes, although an elastic tether 14 is preferred because an elastic tether 14 accommodates a wider range of user heights (by stretching to fit each user) and more securely holds the platform 12 against the user's feet during use due to the additional tension created by stretching the elastic tether 14 . An extendible tether 14 may alternatively comprise one or portions of non-extendible materials combined with an extendible portion which may comprise stretchable cord as above or an extension spring.
Handle 16 is formed on the tether 14 so as to provide the user of device 10 with a convenient place to grab and pull tether 14 away from platform 12 . In the embodiment shown in FIGS. 1-5, handle 16 is a T-shaped assembly attached to a loop end 44 of tether 14 . Handle 16 , perhaps shown best in FIG. 5, has a transverse rod 46 around which tether 14 is looped generally in a center portion 48 of rod 46 so as to define two gripping portions 50 and 52 of rod 46 on either side of center portion 48 . A foam sheath 54 surrounds a portion of tether 14 near the loop end 44 . Sheath 54 has opposing lateral openings 56 and 58 to allow rod 46 to pass through sheath 54 . Sheath 54 also has opposing longitudinal openings 60 and 62 that allow the ends 36 and 38 of the tether 14 to be threaded around rod 46 during assembly so that the loop end 44 of tether 14 can be looped around rod 46 . Gripping portions 50 and 52 are preferably covered with shaped foam tubing so as to form foam grips 64 and 66 , respectively, which provide the user of device 10 with padded gripping surfaces and prevent the loop end 44 of tether 14 and sheath 54 from sliding along the rod 46 during use of the device 10 . Preferably, lateral ends 68 and 70 of rod 46 have cross sectional areas that are greater than the cross sectional area of the interior portions of the rod 46 so as to prevent grips 64 and 66 from sliding off the rod 46 . As shown in FIG. 5, lateral ends 68 and 70 are formed integrally with rod 46 , although lateral ends 68 and 70 can be formed as separate pieces (e.g., as rimmed end caps) that are attached to rod 46 . Alternatively, the tether portions 32 and 34 may be directly tied on to the rod 46 , or otherwise connected by way of a mechanical faster or adhesive, or the like.
In operation, a user mounts the device 10 by placing the user's feet on the foot support surface 18 of platform 12 on either side of opening 42 , grabs the handle 16 with both of the user's hands, pulls the handle 16 away from platform 12 so as to tension tether 14 , and jumps upward. As the user's legs extend during jumping, tether 14 keeps the device 10 under the user's feet, which preferably is further facilitated by the use of an elastic tether 14 which is stretched to provide additional tension. Upon impact, the user's knees bend to help absorb impact and prepare for another extension. Also, upon impact a generally downward, compressive force is applied to foot support surface 18 of platform 12 causing platform 12 to be compressed between the user's feet and the ground (or other rigid surface) as foot support surface 18 moves closer to impact surface 20 so that potential energy is stored in platform 12 . The user extends the user's legs so as to propel the user and the device 10 upward which causes platform 12 to transition from a compressed state to an uncompressed state so as to release the stored potential energy as kinetic energy that creates a rebound force to assist the user in jumping. This motion can be done repeatedly for an indefinite length of time, as each subsequent jump utilizes the same compression of platform 12 to provide a rebound-assisted jump. The user can execute a wide range of maneuvers on device 10 , for example, by maneuvering the user's body as is done to perform maneuvers on conventional skateboards, snow boards, or downhill skis.
FIG. 7 shows a second embodiment of a jumping device 100 according to the present invention having a handle 116 formed integrally with a tether 114 . Device 100 has a high rebound platform 112 that is preferably similar to platform 12 and is fabricated from similar materials in a similar manner. Tether 114 is similar to tether 14 , is fabricated from similar materials in a similar manner, and is attached to platform 112 in the same way that tether 14 is attached to platform 12 except that tether 114 has only one end 136 that is tied to a rod 140 (similar to rod 40 ) located within the plurality of layers 130 of platform 112 . A handle 116 is formed as a loop 172 by tying or otherwise attaching an end 174 of tether 114 to an intermediate portion 176 of tether 114 . Preferably, end 174 is slidably attached to portion 176 so that the user of device 100 can alter the size of loop 172 by sliding end 174 along portion 176 . This can be done by a sliding knot (as shown) or by way of a conventional sliding/clamping device to which an end of tether 114 can be tied. Device 100 can be used in the same manner as device 10 .
As with any of the above specifically disclosed or suggested embodiments, the tether 14 (or 114 ) may comprise a single cord or may include any number of cords, so long as there is a connection to a high rebound platform 12 (or 112 ), and some means is provided to facilitate grasping by a user. A jumping device that interacts with a user's feet and hands is thus provided. Other handle constructions are also contemplated and may be secured in any matter to the tether 14 (or 114 ).
As yet another specifically contemplated embodiment, plural high rebound platforms can be used in combination with independent tethers. That is, two separate platforms may be provided, each having its own tether or tethers. Then, each tether may be combined together to form a handle or be connected to a separately provided handle. Each platform would preferably be connected to a tether or tethers in a way to permit independent leg movement. This may be facilitated by other fastening structures attached between the tether and the tether's platform, or by running plural tethers (or a loop from one tether) through the platform to extend on both sides of a user's foot to keep the platform oriented properly during use.
As still yet another specifically contemplated embodiment of a jumping device according to the present invention, a high rebound platform can comprise a foot support surface that is suspended from a rigid, trampoline-like frame. The foot support surface can be suspended from the frame by coil springs, stretchable cords, or other conventional tension springs devices. In this case, an impact surface created by is a portion of the frame that comes into contact with the ground or other rigid surface during use of the device. A flexible tether is attached to the high rebound platform, preferably in a position to be in between a user's feet, and a handle is formed on the tether to facilitate gripping by a user so as to provide the interaction between at least a hand and a foot of the user. The high rebound platform of this embodiment achieves a compressed state when the platform is compressed by the user's feet such that the foot support surface and/or the springs that attach the foot support surface to the frame, if any, are stretched and store potential energy in the deformed foot support surface and/or springs. When the high rebound platform transitions to the uncompressed state, the foot support surface and/or springs, if any, convert the potential energy to kinetic energy to provide a rebound force to assist the user in jumping. This embodiment is less advantageous for many uses, however, in that it requires more rigid parts and the platform is substantially compressible from only one surface (i.e., from the foot support surface).
Although the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
|
A jumping device having a high rebound platform, a flexible tether operatively connected at a first end thereof to the high rebound platform, and a handle located on the tether. A method of jumping, including providing a jumping device having a high rebound platform, a flexible tether operatively connected at a first end thereof to the high rebound platform, and a handle on the tether, mounting the jumping device by placing a user's foot on the high rebound platform, grabbing the handle, pulling the handle away from the high rebound platform, and jumping so that the high rebound platform alternates between compressed and uncompressed states.
| 0
|
FIELD OF INVENTION
[0001] This invention relates to scaffold structures and, in particular, to top rails for scaffold ladders.
BACKGROUND OF THE INVENTION
[0002] Devices for accessing or mounting a scaffold platform generally consist of ladders, either added on to the structure of the scaffold structure or climbing the structure of the scaffold itself. It is difficult for a climber to easily and safely exit the ladder onto a scaffold deck, as the ladders typically require the climber to swing around the ladder at the point of exit.
OBJECTS OF THE INVENTION
[0003] It is an object of the invention to provide top rails for a scaffold ladder that allows a climber to easily and safely exit the ladder.
[0004] It is an object of the invention to provide top rails for a scaffold ladder that can be easily attached to existing ladders.
SUMMARY OF THE INVENTION
[0005] The invention is top rails of a scaffold ladder, where the top rails are a left and right top rail, each attachable to or forming part of the left and right hand rails respectively of the ladder. The two top rails are designed to diverge, creating room for a climber to easily pass between the two top rails. Each top rail is attachable to either a scaffold horizontal or vertical member through an attachment member positioned at or near the end of each top rail.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 depicts a side view of a scaffold structure with a scaffold ladder having the top rails attached.
[0007] [0007]FIG. 2A is a detailed front view of one embodiment of a top rail.
[0008] [0008]FIG. 2B is detailed side view of one embodiment of a top rail.
[0009] [0009]FIG. 3 is a prospective of a top rail showing an alternative attachment member.
DETAILED DESCRIPTION OF THE INVENTION
[0010] The invention is top rails for scaffold ladders. Shown in FIG. 1 is a scaffold structure 100 , having horizontal 101 and vertical members 102 (collectively, scaffold members). Shown on the vertical members are rings or cups 103 , designed as attachment points for the horizontal and vertical members. Also shown is a scaffold platform 105 .
[0011] Connected to the scaffold structure 100 is a scaffold ladder 10 , having right 11 and left 12 hand rails, and a series of rungs 12 disposed between the hand rails. The top section of the ladder above the platform 105 has a right top rail 1 and a left top rail 2 . As shown, the right top rail 1 is a continuation of the right hand rail 11 , and the left top rail 2 is a continuation of the left hand rail 12 . The left and right top rails 1 and 2 , instead of being parallel, diverge in the plane of the ladder rails 11 , 12 above the scaffold platform. The top rails 1 and 2 are designed to provide the climber with hand holds as the climber ascends the ladder until the climber's feet are at or near the scaffold deck, while the divergence for the top rails 1 and 2 allow the climber to easily pass between the top rails 1 and 2 to gain entry to the scaffold deck 105 . Without the divergence, a climber would be forced to swing around the ladder 11 to gain access to the scaffold platform 105 , an obviously dangerous maneuver. As shown in FIG. 2A, each top rail diverges, or has an outward bend, providing an additional 1 foot 1 inch of clearance.
[0012] Shown in FIG. 2A is a detailed view of one embodiment of a right top rail 1 (a left top rail 2 would, in essence, be a mirror image of a right top rail). The top rail 1 is a pipe having two bent sections. The bottom of the top rail 1 has a flared end 20 for fitting over and attaching to the top of a ladder hand rail, in a male-female interlocking relationship. Obviously, the ladder itself could be made with the top rail incorporated into the hand rail. Other means of joining the top rail to the ladder are available (bolts, brackets, etc).
[0013] As shown, the top rail 1 is a pipe section, having two bends, A and B. Obviously, the top rail could be constructed in two or more pieces or sections to accommodate this geometry. Bend A is positioned about 5 inches from the flared end 20 or join with the ladder and is in the plane of the ladder hand rails 11 and 12 . The Bend produces the divergence in the right 1 and left top rails 2 away from the ladder hand rails. Bend B (see FIG. 2B) is located at the top of the top rails 1 and 2 , and is 90 degrees from the plane of bend A. The purpose of Bend B is to position the top rail 1 for attachment to the scaffold structure 100 through attachment member 30 . The scaffold ladder 11 is generally offset from the scaffold structure 100 due to the clamping of the ladder to the structure (one type of clamp is shown in U.S. Pat. No. 6,044,930, incorporated by reference). Since the scaffold ladder 11 is attached to the scaffold structure 100 in a vertical orientation and generally offset from the scaffold structure, the top rails 1 and 2 , being a continuation of the hand rails 11 and 12 , will require a top section which is offset at 90 degrees to properly position the attachment member 30 for attachment to the scaffold structure 100 . For a scaffold ladder attached to the scaffold by the clamp shown in U.S. Pat. No. 6,044,930, a 90 offset of about 9.75 inches is suitable.
[0014] Also shown is attachment member 30 , for attaching the top rail 1 or 2 to the scaffold structure 100 . The embodiment shown is a hook section with a pivotal latch (not shown) for grasping the cups 103 located on the vertical scaffold members 102 . A detailed description of this particular latch is contained in U.S. Pat. Nos. 5,078,532 and 5,028,164 issued to Williams, hereby incorporated by reference. Other types of attachment members 30 could be used. For instance, simply a hooked section for attachment to a scaffold horizontal member 101 , or a clamp attachable to either a horizontal or vertical scaffold member (a clamp attachable to a vertical member is shown in FIG. 3), a hook section attachable or engagable to an annular ring or cup positioned on the vertical scaffold member, or alternatively, attached by U-bolts around a vertical or horizontal scaffold member though a plate or flange positioned on the top of the top rail, etc.
[0015] Finally, as shown in FIG. 1, is gate 50 , attached to the scaffold structure 100 and positioned to open between the top rails. Gate 50 with opens inward toward the scaffold interior and is present to block the opening between the top rails as a safety measure.
[0016] Although the present invention has been described in terms of specific embodiments, it is anticipated that alterations and modifications thereof will no doubt become apparent to those skilled in the art which are intended to be included within the scope of the following claims.
|
Top rails of a ladder, where the top rails include a left and right top rail, each attachable to or forming part of the left and right hand rails respectively of the ladder. The two top rails are designed to diverge, creating room for a climber to easily pass between the two top rails. Each top rail is attachable to either a scaffold horizontal or vertical member through an attachment member positioned at or near the end of each top rail.
| 4
|
This is a continuation-in-part application of application Ser. No. 327,593, filed on Mar. 23, 1989 now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a process for producing a high density printed wiring board by an additive process.
Printed wiring boards are generally produced economically by an additive process wherein necessary wiring conductors are formed by electroless plating. According to the additive process, necessary wiring patterns are formed by forming adhesive layers having thereon an electroless plating catalyst such as palladium on surfaces of an insulating substrate having the same catalyst for electroless plating, masking portions other than circuit forming portions with a plating resist selectively roughening an adhesive surface to be formed into circuit portions with a chemical solution such as chromic acid, or the like, neutralizing and washing with water, and forming conductors on circuit portions by electroless copper plating.
With a recent demand for miniaturizing and light weighting electronic devices, printed wiring boards with high density have also been demanded, resulting in narrowing distances between through-holes and between wiring conductors. As a result, by an electric field formed between neighboring wiring conductors or conductors of inner walls of through-holes, various treating solutions retained in surface or inner portions of the insulating substrate supporting the conductors are activated to easily bring about electrolytic corrosion which accelerate migration of conductors. Thus, it is impossible to make the distance between conductors 0.15 mm or less. Further, it is also impossible to narrow the distances between through-holes, so that in order to obtain high density wiring, only the width of conductors should be reduced, resulting in producing a limit to the wiring density. As a cause for bringing about electrolytic corrosion, it is considered that migration of copper is brought about by ionic impurities contained in additive layers formed on the insulating substrate or a residue of a special treating solution used in the additive process when an electric field is applied between wiring conductors under a high temperature and high humidity.
In order to solve the problem of electrolytic corrosion, it is proposed a process comprising conducting electroless nickel plating on whole surfaces of an insulating substrate having adhesive layers thereon and through holes therein, forming a plating resist on portions other than circuit portions, electroplating copper on the circuit portions, peeling the resist, and removing nickel on non-circuit portions with an ammonium persulfate solution containing benzotriazole (Japanese Patent Examined Publication No. 56-47716). This process is illustrated by FIGS. 3(a) to 3(h) wherein numeral 11 denotes an insulating substrate, numeral 12 denotes an adhesive layer, numeral 13 denotes a through-hole, numeral 14 denotes a nickel plated layer, numeral 15 denotes a plating resist, numeral 16 denotes a copper plated layer, and numeral 17 denotes a printed wiring board after removing the nickel layer. But according to this process, since circuit conductors are formed by electroplating of copper on the whole surface of electroless plated nickel, there arise various problems in that the plating thickness in the through-holes obtained by electroplating of copper is not uniform, high density of wiring is difficult due to no room for changing hole diameters at the time of planing or due to no surface smoothness of conductors necessary for mounting various parts thereon, and the like.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a process for producing a printed wiring board provide a process for producing with high density and excellent in resistance to plating electrolytic corrosion as well as excellent in plating processability,
The present invention provides a process for producing a printed wiring board by an additive process characterized by forming a layer of metal such as nickel which is slight in migration by and electric field by electroless plating on an insulating substrate, and forming a metallic conductor having electric conductivity such as copper thereon by electroless plating.
The present invention also provide a process for producing a printed wiring board by an additive process characterized by forming a thin layer of copper on an insulating substrate, forming a layer of metal such as nickel which is slight in migration by an electric field by electroless plating on the copper thin layer, and forming a metallic conductor having electric conductivity such as copper thereon by electroless plating.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(a) to 1(f) are cross-sectional views explaining one embodiment of the process of the present invention.
FIG. 2 is a cross-sectional view of a printed wiring board wherein only a first resist layer is used.
FIGS. 3(a) to 3(h) are cross-sectional views explaining a process of prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The process of the present invention includes (I) a process comprising a step of forming a metallic layer of Ni, Ni alloy, Co, Co alloy, Pd or Ag on an insulating substrate, and a step of forming an electric conductive metallic layer such as copper thereon, and (II) a process comprising a step of forming a thin layer of copper on an insulating substrate, a step of forming a layer of metal such as nickel which is slight in migration by an electric field by electroless plating on the copper thin layer, and forming a metallic conductor having electric conductivity such as copper thereon by electroless plating.
More concretely, the process (I) fundamentally comprises (with referring to FIGS. 1(a) to 1(g)):
(i-a) forming an adhesive layer containing an electroless plating catalyst on surfaces of an insulating substrate containing an electroless plating catalyst (FIG. 1(a)),
(ii-b) drilling through-holes in the resulting insulating substrate (FIG. 1(b)),
(iii-c) masking portions except for the through-holes and circuit forming portions and markings with a first resist for electroless plating (FIG. 1(c)),
(iv-d) dipping the resulting substrate in a chemical roughening solution to selectively roughen the portions not masked with the resist (FIG. 1(d)),
(v-e) dipping the thus treated substrate in an electroless nickel plating solution to form nickel plated layers on the roughened portions not masked with the first resist (FIG. 1(e)),
(v-ef) masking portions except for the through-holes and circuit forming portions with a second resist for electroless plating, the second resist forming a circuit forming pattern on the nickel plated layers that is 5 to 10 μm narrower than the the pattern of the first resist so that the second resist covers a portion of the nickel plated layers, as shown in FIG. 1(f), and
(vi-f) dipping the nickel plated substrate in an electroless copper plating solution to conduct copper plating on the nickel plated layers (FIG. 1(f)).
In FIGS. 1(a) to 1(f), numeral 1 denotes an insulating substrate, numeral 6 denotes an adhesive layer, numeral 5 denotes a through-hole, numeral 8 denotes a first plating resist, numeral 8' denotes a second plating resist, numeral 7 denotes a chemically roughened surface, numeral 3 denotes a nickel plated layer, numeral 4 denotes a copper plated layer.
By the step (i-a), an adhesive layer containing an electroless plating catalyst is formed on both sides of an insulating substrate containing an electroless plating catalyst. As the insulating substrate, there can be used conventionally used ones such as paper-epoxy resin laminates (e.g. LE-168, LE-144, etc. mfd. by Hitachi Chemical Co., Ltd.), paper-phenol resin laminates, glass fiber-epoxy resin laminates, glass cloth-epoxy resin laminates, glass cloth-polyimide laminates, etc.
As the electroless plating catalyst, there can be used palladium and its compounds, platinum and its compounds, rhodium and its compounds, etc. conventionally used in this art.
As the adhesive layer there can be used that containing as a major component a rubber component such as acrylonitrile-butadiene rubber (NBR), butadiene rubber, styrene-butadiene rubber (SBR), etc. added with a phenolic resin, melamine resin or an epoxy resin and an inorganic filler such as silica, zirconium silicate, etc.
In the step (i-a), the insulating substrate containing an electroless plating catalyst and the adhesive layer containing an electroless plating catalyst are used.
By the step (ii-b), through-holes are drilled in the resulting substrate.
Through-holes are formed by using an apparatus such as a punch, a drill, etc., conventionally used for drilling through-holes in wiring boards.
By the step (iii-c), portions except for the through-holes and circuit forming portions are masked with a first resist for electroless plating and, preferably, markings are provided for adjusting the position of the first resist. The markings can be made according to a conventional technique.
As the resist, there can be used an ultraviolet (UV) curing type resist film obtained by forming a light curable resin into a film followed by curing, a film obtained by, for example, screen printing a UV curable resist ink or a thermosetting resist ink, etc., followed by curing. As the material for forming the resist, there can be used conventionally used ones such as epoxy resins, acrylic resins, etc. These resists should not be peeled off during the steps of dipping in the electroless nickel plating solution the electroless copper plating solution, and other chemical solutions used for pre-treatment or after-treatment.
By the step (iv-d), the portions not masked with the resist are selectively roughened by dipping the resulting substrate in a chemical roughening solution.
As the chemical roughening solution, there can be used those conventionally used in the additive process, for example, a mixed solution of chromic acid and sulfuric acid, a mixed solution of chromic acid and borofluoric acid, etc.
By the step (v-e), nickel plated layers are formed on the roughened portions not masked with the resist by dipping the thus treated substrate in an electroless nickel plating solution.
As the electroless nickel plating solution, there can be used a conventionally used one comprising a hypophosphite as a reducing agent, phosphoric acid or boron, a nickel compound such as nickel chloride, nickel nitrate, or the like. Such a nickel plating solution can be used at a temperature of preferably 40° to 95° C. Such an electroless nickel plating solution is available commercially under trade names such as Blue Shumer (mfd. by Japan Kanigen Co., Ltd.), "Top Nimaron (mfd. by Okuno Seiyaku K.K.), Nimuden (mfd, by Uemura Kogyo K.K.).
The thickness of the nickel plated layer is preferably in the range of 0.5 to 10 μm from the viewpoint of prevention of electrolytic corrosion, uniformity in thickness of the plated layer and the thickness of finally produced wiring board.
By the step (v-ef), the portions except for the through-holes and circuit forming portions are masked with the second resist for electroless plating, said second resist being 5 to 10 μm narrower than the first resist. Further, the second resist also has markings for adjusting the position according to a conventional technique so as to prevent a shift from the first resist.
By the step (vi-f), a copper plated layer is formed on the nickel plated layer by dipping the nickel plated substrate in an electroless copper plating solution.
As the electroless copper plating solution, there can be used a conventional one comprising:
______________________________________CuSO.sub.4.5H.sub.2 O 10 g/literNaCN 15-30 mg/literformaline (36%) 4 ml/literEDTA 40 g/literpH 12.5 (adjusted by NAOH)______________________________________
The electroless copper plating can be carried out preferably at 40° to 90° C. to form a copper plated film of preferably 12 to 70 μm.
In the above-mentioned process (I), an insulating substrate containing no electroless plating catalyst can be used in the step (i-a) and roughened surfaces can be selectively exposed in place of selective roughening in the step (i-d).
Such a process (I-1) comprises steps of
(i-a') forming an adhesive layer on surfaces of an insulating substrate,
(ii-b) drilling through-holes in the resulting insulating substrate,
(iii-d') dipping the resulting substrate in a chemical roughening solution to roughen whole surfaces,
(iv-c) masking portions except for the through-holes and circuit forming portions with a first resist for electroless plating,
(v-e) dipping the thus treated substrate in an electroless nickel plating solution to form nickel plated layers on the roughened portions not masked with the first resist,
(v-ef) masking portions except for the through-holes and circuit forming portions with a second resist for electroless plating, and the pattern of second resist is 5 to 10 μm narrower on the nickel plated layers than the first resist, and
(vi-f) dipping the nickel plated substrate in an electroless copper plating solution to conduct copper plating on the nickel plated layers.
In the step (i-a'), as the insulating substrate containing no electroless plating catalyst, there can be used glass cloth-epoxy resin laminates (e.g. LE-47N, LE-61N, etc. mfd. by Hitachi Chemical Co., Ltd.).
The steps (ii-b), (iv-c), (v-e), and (vi-f) are the same as mentioned above.
The process (I) can also be modified as a process (I-2) comprising:
(i-a') forming an adhesive layer on surfaces of an insulating substrate,
(ii-b) drilling through-holes in the resulting insulating substrate,
(iii-c) masking portions except for the through-holes and circuit forming portions with a first resist for electroless plating,
(iv-d) dipping the resulting substrate in a chemical roughening solution to selectively roughen the portions not masked with the first resist,
(v-g) dipping the resulting substrate in an aqueous solution containing palladium ions,
(vi-h) dipping the resulting substrate in a reducing agent solution,
(vii-e') dipping the thus treated substrate in an electroless plating solution to form plated layers of nickel, a nickel alloy, cobalt, a cobalt alloy, palladium, gold or a mixture thereof on the roughened portions not masked with the first resist,
(vii-ef) masking portions except for the through-holes and circuit forming portions with a second resist for electroless plating, and the second resist is 5 to 10 μm narrower than the first resist, and
(viii-f) dipping the thus plated substrate in an electroless copper plating solution to conduct copper plating on the plated layers.
In this process, the steps (ii-b), (iii-c), (iv-d), (vii-ef) and (viii-f) are the same as mentioned above.
In the step (i-a'), as the insulating substrate, there can be used paper-phenol resin laminates, paper-epoxy resin laminates, glass cloth-epoxy resin laminates, glass cloth-polyimide resin laminates, etc. (e.g. LP-47F, LE-44, LE-67, LI-67, LI-68, mfd. by Hitachi chemical Co., Ltd.). These insulating substrates may includes electroless plating catalysts such as palladium, platinum, rhodium, etc. Further, the insulating substrate may includes inner circuits therein.
As the material for forming the adhesive layer, there can be used a resin composition containing NBR as a major component, a resin composition containing NBR and chlorosulfonated polyethylene as major components, a resin composition containing an epoxy resin as a major component, etc. These resin compositions nay contain one or more fillers such as zirconium silicate, silica, calcium carbonate, aluminum hydroxide, and the like. Further, these resin compositions may contain an electroless plating catalyst such as palladium, platinum, rhodium, etc.
In the step (v-g), as the aqueous solution containing palladium ions, there can be used an aqueous solution obtained by adding hydrochloric acid to Red Shumer containing palladium ions (a trade name, mfd. by Japan Kanigen Co. Ltd.) and if necessary, further adding palladium chloride as an extender, or diluting with water to adjust properly the palladium concentration, or an aqueous solution obtained by dissolving palladium chloride in hydrochloric acid with a hydrogen chloride concentration of 2 to 20% by weight. The use of an aqueous solution of palladium in a concentration of 0.01 to 0.6% by weight is preferable for making the thickness of nickel and the like plated layer uniform.
In the step (vi-h), as the reducing agent for reducing palladium, there can be used inorganic reducing agents such as a hypophosphite, a borohydride, or organic reducing agents such as amine borane, hydrazine, etc. These compounds are generally used as a reducing agent for electroless plating solutions of copper, nickel, cobalt, gold or palladium.
After the reducing agent treatment, it is preferable to conduct washing with water or an aqueous solution of hydrochloric acid.
By employing the step (v-g) and (vi-H), the following electroless nickel plating can be carried out at a lower temperature (e.g. 60°-70° C.) compared with the case of not employing the steps (v-g) and (vi-h) wherein the temperature of 90° to 95° C. is necessary.
In the step (vii-e'), a plated layer is formed by using an electroless plating solution of nickel, a nickel alloy such as Ni-W alloy, Ni-Co alloy, etc., cobalt, a cobalt alloy such as CO-W alloy, etc., palladium or gold, conventionally used in this art. More concretely, there can be used commercially available ones such as Blue Shumer (a trade name, mfd. by Japan Kanigen Co., Ltd.) which is a nickel plating solution containing a hypophosphite as a reducing agent, and phosphorus or boron, Top Nikoron (a trade name, mfd. by Okuno Seiyaku K.K.), Nimuden (a trade name, mfd. by Uemuka Kogyo K.K.), etc.
In the case of palladium or gold plated layer, the thickness of the plated layer is preferably 0.5 to 5 μm from the viewpoint of uniformity of thickness of plated layer and the thickness of finally finished wiring board. On the other hand, in the case of plated layer of other metals, the thickness of 0.5 to 10 μm is preferable by the same reasons as mentioned above.
The process (I-2) can be modified as a process (I-3) comprising
(i-a) forming an adhesive layer containing an electroless plating catalyst on surfaces of an insulating substrate containing an electroless plating catalyst,
(ii-b) drilling through-holes in the resulting substrate,
(iii-c) masking portions except for the through-holes and circuit forming portions with a first resist for electroless plating,
(iv-d) dipping the resulting substrate in a chemical roughening solution to selectively roughen the portions not masked with the first resist,
(v-e') dipping the thus treated substrate in an electroless plating solution to form plated layers of nickel, a nickel alloy, cobalt, a cobalt alloy, palladium, gold or a mixture thereof on the roughened portions not masked with the first resist,
(v-ef) masking portions except for the through-holes and circuit forming portions with a second resist for electroless plating, and the second resist is 5 to 10 μm narrower than the first resist, and
(vi-f) dipping the thus plated substrate in an electroless copper plating solution to conduct copper plating on the plated layers.
The steps of (v-g) and (vi-h) of the process (I-2) can be omitting by changing the step ii-a') to the step (i-a).
As mentioned previously, the electrolytic corrosion is caused by ionic impurities contained in the adhesive layers formed on both sides of the insulating substrate or a residue of special treating solutions used in the additive process, when an electric field is applied between wiring conductors under high temperatures and high humidity to migrate copper. By interposing nickel, which is a substance slight in migration of components by an electric field, between copper wiring conductors and the insulating substrate, deterioration in insulating properties on the surfaces of insulating substrate due to electrolytic corrosion at the time of application of voltage can be prevented. At this time, by adsorbing and reducing palladium selectively on circuit forming portions not masked with the resist, it becomes possible to deposit nickel or the like metal in a short time. Further, since the thickness of undercoating copper plated layer is 3 μm or less, more preferably 1 μm or less, deterioration in insulating properties by electrolytic corrosion is remarkably rare. Even if electrolytic corrosion takes place, since the thickness is thin and the migrating amount of copper is small, conductors are not short-circuited each other.
But, when a printed wiring board having the cross-sectional structure as shown in FIG. 2 is placed under severe conditions such as a humidity of 85%, a temperature of 85° C. and an application of a direct current of 100 V, electrolytic corrosion sometimes takes place. This seems to be caused by a vacant space at the boundary 10 between the nickel layer 3, the copper layer 4 and the resist layer 8 (only one resist layer is used) due to a difference of expansion rates of the resist layer 8 and the adhesive layer 6, said vacant space being filled with water, which makes the copper layer contact with the adhesive layer, resulting in causing electrolytic corrosion.
In contrast, since the printed wiring board of the present invention has the cross-sectional structure as shown in FIG. 1(f), even if a vacant space is produced at the boundary 11 between the copper layer 4 and the second resist 8' and water is filled therein, the electrolytic corrosion is completely prevented by the nickel layer 3 under the vacant space and the first resist layer 8 under the second resist layer 8'.
The present invention is illustrated by way of the following Examples, in which all percents are by weight unless otherwise specified.
EXAMPLE 1
On a paper-epoxy resin laminate (LE-144, a trade name, mfd. by Hitachi Chemical Co., Ltd.) containing palladium chloride as an electroless plating catalyst, an adhesive containing NBR as a major component, and an alkyl phenol resin, an epoxy resin, and silica and zirconium silicate as fillers and palladium chloride, dissolved in a solvent was coated, dried and cured with heating to give an insulating substrate covered with the adhesive layers.
After drilling holes at predetermined positions by a punch press, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form the resist on portions other than circuit forming portions.
After forming the resist, the resulting substrate was dipped in a mixed solution of chromic acid and sulfuric acid (CrO 2 255 g, concentrated H 2 SO 4 210 ml diluted with water to make the solution 1 liter as a whole) at 40° C. for 15 minutes to selectively roughening the circuit forming portions on the adhesive layers, followed by washing with water and neutralization.
The thus roughened substrate was dipped in an electroless nickel plating solution containing a hypophosphite as a reducing agent (Blue Shumer, a trade name, mfd. by Japan Kanigen Co., Ltd.) at 90° C for 10 minutes, followed by washing with water. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit providing a pattern 5 to 10 μm narrower than that of the first resist. Then, the resulting nickel plated substrate was dipped in an electroless copper plating solution comprising:
______________________________________CuSO.sub.4.5H.sub.2 O 10 g/literNaCN 15 mg/literformaline (36%) 4 ml/literEDTA 40 g/literpH 12.5______________________________________
at 70° C. to deposit copper in 70 μm thick. Then, a solder resist was screen printed on the substrate surfaces other than the through-holes, and cured with heating to give a sample of printed wiring board.
EXAMPLE 2
On a glass cloth-epoxy resin laminate containing palladium chloride, the same adhesive as used in Example 1 was coated and cured with heating to give an insulating substrate. Then, through-holes were drilled with a high speed drilling machine. A photosensitive resist film was adhered to the adhesive layers, followed by selective exposing to light and development to form a resist.
After chemically roughening the resulting substrate with the same chemical roughening solution as used in Example 1, the resulting substrate was dipped in an electroless nickel plating solution (Shumer SB-55, a trade name, mfd. by Japan Kanigen Co., Ltd.) at 90° C. for 5 minutes to deposit nickel boron. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist. Then, the resulting substrate was dipped in the same electroless copper plating solution as used in Example 1 to deposit copper in 22 μm thick. Then, a solder resist was screen printed on the substrate surfaces other than the through-holes and cured with heating in the same manner as described in Example I to give a sample of printed wiring board.
EXAMPLE 3
On a paper-epoxy resin laminate (LE-47N, a trade name, mfd. by Hitachi Chemical Co., Ltd.), an adhesive containing NBR as a major component, an alkylphenol resin, and inorganic fillers of silica and zirconium silicate uniformly dissolved in a mixed solvent of methyl ethyl ketone and Cellosolve acetate was coated, dried and cured with heating to give an insulating substrate covered with the adhesive layers of about 30 μm thick.
After drilling holes at predetermined positions by a punch press, the resulting substrate was subjected to chemical roughening in the same manner as described in Example 1, followed by washing with water and neutralization. Then, the resulting substrate was dipped in 20% HCl for 1 minute, followed by dipping in a sensitizer HS-201B (a trade name, mfd. by Hitachi Chemical Co., Ltd.) containing palladium chloride and stannous chloride to adsorb the electroless plating catalyst. After laminating a resist film for electrolESS plating (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) using a vacuum laminator, the resulting substrate was exposed to light and developed to mask non-circuit portions with the resist.
The resulting substrate was dipped in the same electroless nickel plating solution a used in Example 1 at 80° C. for 10 minutes. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist. Then, the substrate was dipped in the same electroless copper plating solution as used in Example 1 at 70° C. to deposit a copper plated layer of 20 μm thick. Then, a solder resist was screen printed on the substrate surfaces other than the through-holes, and cured with heating to give a sample of printed wiring board.
COMPARATIVE EXAMPLE 1
The process of Example 1 was repeated excepted for not conducting the electroless nickel plating.
COMPARATIVE EXAMPLE 2
The process of Example 2 was repeated except for not conducting the electroless nickel plating.
In the above-mentioned samples, both the conductor width and the space between conductors were made 0.1 mm, the through-hole diameter was made 0.6 mm, and the number of through-holes was made 200. Conductor patterns for evaluating electrolytic corrosion were formed on both sides of insulating substrates (via through-holes) for connecting through-holes were formed.
Electrolytic corrosion (EC) between conductors was tested by placing samples under a temperature of 65° C. and relative humidity (RH) of 95%, applying a direct current of 50 V between conductors continuously, taking a part of samples after predetermined periods (100 hours and 300 hours), and measuring insulation resistance values between conductors.
Electrolytic corrosion (EC) between through-holes was tested by observing the change of cross-section of through-hole after 300 hours by the naked eye.
Solder heat resistance and peeling strength were measured according to JIS C-6481.
The results are shown in Table 1.
As is clear from Table 1, both the electrolytic corrosion between conductors and between through-holes are improved remarkably, while maintaining good solder heat resistance and peeling strength.
TABLE 1__________________________________________________________________________ Examples Comparative Examples 1 2 3 1 2__________________________________________________________________________EC betweenelectrodesafter 100 hrs No change in No change in No change in Resistance No change in resistance value resistance value resistance value value was resistance value reduced by 50%after 300 hrs No change in No change in No change in Short- short- resistance value resistance value resistance value circuited circuitedEC between No change No change No change Migration Migrationthrough-holes of copper of copperafter 300 hrsSolder heat ≧60 sec. ≧60 sec. ≧60 sec. ≧60 sec. ≧60 sec.resistance (260° C.)Peeling 2.0 2.1 1.8 2.0 2.1strength (kgf/cm)__________________________________________________________________________
EXAMPLE 4
On a paper-epoxy resin laminate (LE-44, a trade mane, mfd. by Hitachi Chemical Co., Ltd.), a solution of adhesive containing NBS as a major component, an alkylphenol resin, an epoxy resin, and silica and zirconium silicate as fillers was coated, and cured with heating to form adhesive layers. The resulting substrate was drilled by a punch press to provide through-holes at predetermined positions. A photoresist for electroless plating (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposure to light and development to form a plating resist on non-circuit portions.
Then, the resulting substrate was dipped in a mixed solution of CrO 2 (55 g/liter) and concentrated H 2 SO 4 (210 ml) diluted with water to make a total volume 1 liter at 40° C. for 15 minutes to chemically roughen circuit portions, followed by neutralization and washing with water.
The resulting substrate was dipped in an aqueous solution of 200 ml of Red Shumer (a trade name, mfd. by Japan Kanigen Co., Ltd.) and 100 ml of 35N HCl at room temperature for 15 minutes, washed with water, dipped in an aqueous solution of sodium hypophosphite (60 g/liter) at 50° C. for 15 minutes, and washed with water.
The resulting substrate was dipped in an electroless nickel plating solution containing sodium hypophosphite as a reducing agent (Blue Shumer, a trade name, mfd. by Japan Kanigen Co., Ltd.) at 90° C. for 20 minutes to form nickel plating layers of about 2 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist. Then, the substrate was dipped in the same electroless copper plating solution as used Ln Example 1 at 70° C. to form copper plating layers of 25 μm thick on the nickel plating layers.
A solder resist was screen printed on both sides of the substrate other than the through-holes, and cured with heating to give a sample of printed wiring board.
EXAMPLE 5
On a glass cloth-epoxy resin laminate (LE-67, a trade name, mfd. by Hitachi Chemical Co., Ltd.), the same adhesive as used in Example 4 was coated and cured with heating. Through-holes were drilled in the substrate using a high speed drilling machine at predetermined positions and a plating resist was formed on the substrate in the same manner as described in Example 4. Chemical roughening was conducted in the same manner as described in Example 4.
The resulting insulating substrate was dipped in an aqueous solution of palladium chloride (5 g/liter) and 35N HCl (200 ml/liter) at room temperature for 15 minutes, washed with water, dipped in an aqueous solution of sodium borohydride (3 g/liter) at 50° C. for 10 minutes, and washed with water.
The resulting insulating substrate was dipped in an electroless nickel/tungsten alloy plating solution comprising:
______________________________________nickel sulfate 7 g/litersodium tungstate 35 g/litersodium citrate 20 g/litersodium hypophosphite 10 g/liter______________________________________
with pH 9.8 at 93° C. for 40 minutes to form an alloy plated layer of about 2 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit having a pattern 5 to 10 μm narrower than that of the first resist.
Electroless copper plating and formation of solder resist were carried out in the same manner as described in Example 4 to give a sample of printed wiring board.
EXAMPLE 6
On a glass cloth-epoxy resin laminate containing palladium chloride (LE-168, a trade name, mfd. by Hitachi Chemical Co., Ltd.), adhesive layers were formed in the same manner as described in Example 4.
Formation of through-holes, chemical roughening and pre-treatment for plating were carried cut in the same manner as described in Example 4.
The resulting insulating substrate was dipped in an electroless nickel/cobalt alloy plating solution comprising:
______________________________________nickel sulfate 30 g/litercobalt sulfate 30 g/litersodium glycolate 100 g/litersodium hypophosphite 22 g/liter______________________________________
with pH 4.5-5.0 at 92° C. for 40 minutes to form an alloy plated layer of about 10 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist.
Electroless copper plating and formation of solder resist were carried out in the same manner as described in Example 4 to give a sample of printed wiring board.
EXAMPLE 7
On the same substrate as used in Example 5, adhesive layers were formed in the same mannar as described in Example 5.
The resulting substrate was dipped in an aqueous solution containing palladium chloriie (5 g/liter), 35N HCl (200 ml/liter) and dimethylformamide (DMF) (5 ml/liter) for 10 minutes, washed with water, dipped in an aqueous solution of dimethylamino borane (5 g/liter) at 50° C. for 10 minutes), and washed with water.
Then, the resulting substrate was dipped in an electroless cobalt plating solution comprising:
______________________________________cobalt chloride 35 g/litersodium citrate 116 g/litersodium hypophosphite 10 g/liter______________________________________
with pH 9.0 at 90° C. for 60 minutes to form a plated layer of about 6 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist.
Electroless copper plating and formation of solder resist were carried out in the same manner as described in Example 4 to give a sample of printed wiring board.
EXAMPLE 8
On the same insulating substrate as used in Example 7, the formation of adhesive layers, formation of plating resist layers, chemical roughening and plating pre-treatment were carried out in the same manner as described in Example 5.
The resulting substrate was dipped in an electroless palladium plating solution comprising:
______________________________________tetramine palladium chloride 7.5 g/literEDTA-2Na 8.0 g/literammonia water 280 g/literhydrazine (1 mole/liter) 8 ml/liter______________________________________
at 38° C. for 60 minutes to form a plated layer of about 1 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist.
Electroless copper plating and formation of solder resist were carried out in the same manner as described in Example 4 to give a sample of printed wiring board.
EXAMPLE 9
Using the same insulating substrate as used in Example 4, the formation of adhesive layers and plating resist layers, chemical roughening and plating pre-treatment were carried out in the same manner as described in Example 4.
The resulting substrate was dipped in an electroless gold plating solution comprising:
______________________________________potassium cyanoaurate 2 g/literammonium chloride 75 g/litersodium citrate 50 g/litersodium hypophosphite 10 g/liter______________________________________
with pH 7.0-7.5 at 92° C. for 30 minutes to form a plated layer of about 0.5 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist.
Electroless copper plating and formation of solder resist were carried out in the same manner as described in Example 4 to give a sample of printed wiring board.
EXAMPLE 10
On a paper-epoxy resin laminate containing palladium chloride as an electroless plating catalyst (LE-144, a trade name, mfd. by Hitachi Chemical Co., Ltd.), the same adhesive as used in Example 4 was coated, and cured with heating to provide an insulating substrate covered with adhesive layers.
Drilling of through-holes, formation of a plating resist and chemical roughening were conducted in the same manner as described in Example 4.
The resulting substrate was dipped in an aqueous solution containing 0.2 g of palladium chloride, 100 ml of 35N HCl and 1000 ml of water at room temperature for 5 minutes to adsorb the palladium chloride selectively on the roughened surfaces. After washing with water, the substrate was dipped in a 10% aqueous solution of sodium hypophosphite (a reducing solution) at 60° C. for 3 minutes for activation.
Then, the resulting substrate was dipped in an electroless nickel plating solution (Blue Shumer, a trade name, mfd. by Japan Kanigen Co., Ltd.) at 60° C. for 10 minutes to form nickel plated layers of about 4 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist.
Electroless copper plating and formation of solder resist were carried out in the same manner as described in Example 4 to give a sample of printed wiring board.
EXAMPLE 11
On the same glass cloth-epoxy resin laminate as used in Example 5, the same adhesive as used in Example 4 was coated and cured with heating to give an insulating substrate covered with adhesive layers.
Then, through-holes were drilled in the substrate using a high speed drilling machina. Photosensitive resist films were adhered to both sides of the substrate, selectively exposed to light and developed to form plating resists.
After chemically roughening in the same manner as described in Example 4, the substrate was dipped in an aqueous solution containing 200 ml of Red Shumer containing palladium ions (a trade name, mfd. by Japan Kanigen Co., Ltd.), 100 ml of 35N HCl, and 800) ml of water (Pd concentration: about 0.01%) at room temperature for 3 minutes, washed with water, and dipped in an aqueous ammonium solution of 0.5% by dimethyl aminoborane (a reducing solution) at 50° C. for 3 minutes for activation. After repeating this step twice, an electroless nickel plating was carried out by dipping the substrate in an electroless nickel plating solution (Shumer SB-55, a trade name, mfd. by Japan Kanigen Co., Ltd.) at 60° C. for 5 minutes to form a nickel plated layer of about 3 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist o the nickel circuit 5 to 10 μm narrower than the first resist.
Electroless copper plating and formation of solder resist were carried out in the same manner as described in Example 4 to give a sample of printed wiring board.
COMPARATIVE EXAMPLE 3
The process of Example 4 was repeated except for not conducting electroless nickel plating to give a sample of printed wiring board.
COMPARATIVE EXAMPLE 4
The process of Example 5 was repeated except for not conducting electroless nickel/tungsten alloy plating to give a sample of printed wiring hoard.
COMPARATIVE EXAMPLE 5
The process of Example 10 was repeated except for not conducting electroless nickel plating to give a sample of printed wiring board.
COMPARATIVE EXAMPLE 6
The process of Example 11 was repeated except for not conducting electroless nickel plating to give a sample of printed wiring board.
COMPARATIVE EXAMPLE 7
The process of Example 10 was repeated except that the electroless nickel-plating was conducted without dipping in the aqueous solution containing palladium ions. In this case, no uniform plated layer was formed on the circuit portions even if the nickel plating was conducted at the solution temperature of 60° C. for 60 minutes.
COMPARATIVE EXAMPLE 8
The process of Example 11 was repeated except that the electroless nickel plating was conducted without dipping in the aqueous solution containing palladium ions. In this case, no plated layer was formed on the circuit portions even if the nickel plating was conducted at the solution temperature of 60° C. for 60 minutes.
In the above-mentioned samples of Examples 4 to 11 and Comparative Examples 3 to 8, both the conductor width and the space between conductors were made 0.1 mm, the through-hole diameter was made 0.6 mm, and the number of through-holes was made 200. Conductor patterns were made in the same manner as described in Examples 1 to 3.
Electrolytic corrosion (EC) between conductors, and between through-holes (generation of dendrite), solder heat resistance and peeling strength were measured in the same manner as described in Examples 1 to 3. The results are shown in Table 2.
As is clear from Table 2, both the electrolytic corrosion between conductors and between through-holes are improved remarkably, while maintaining good solder heat resistance and peeling-strength. Further the nickel plating can be carried out at not so high temperatures.
TABLE 2__________________________________________________________________________ Examples 4 5 6 7 8 9 10 11__________________________________________________________________________EC betweenelectrodesafter 100 hrs No change No change No change No change No change No change No change No changeafter 300 hrs No change No change No change No change No change No change No change No changeEC between No change No change No change No change No change No change No change No changethrough-holesafter 300 hrsSolder heat ≧60 sec. ≧60 sec. ≧60 sec. ≧60 sec. ≧60 sec. ≧60 sec. ≧60 ≧60 sec.resistance (260° C.)Peeling 2.1 2.1 2.1 2.1 1.8 1.9 2.1 2.1strength (kgf/cm)__________________________________________________________________________ Comparative Examples 3 4 5 6 7 8__________________________________________________________________________ EC between electrodes after 100 hrs Resistance No change Resistance No --ange -- value was value was reduced by 50% reduced by 50% after 300 hrs Short- Short- Short- Short- circuited circuited circuited circuited EC between Migration Migration Migration Migration -- -- through-holes of copper of copper of copper of copper after 300 hrs Solder heat ≧60 sec. ≧60 sec. ≧60 ≧60 --c. -- resistance (260° C.) Peeling 2.0 2.1 1.8 1.9 -- -- strength (kgf/cm)__________________________________________________________________________
EXAMPLE 12
On a glass cloth-epoxy resin laminate containing palladium chloride as an electroless plating catalyst (LE-144, a trade name, mfd. by Hitachi Chemical Co., Ltd.), a solution of adhesive containing NBR as a major component, an alkylphenol resin, an epoxy resin, silica, zirconium silicate as inorganic fillers, and palladium chloride was coated and cured with heating to form adhesive layers.
After drilling through-holes at predetermined positions using a punch press, the resulting substrate was laminated with a photoresist film for electroless plating (Photec SR-3000) using a vacuum laminator, exposed to light on non-circuit portions, and developed to remove non-exposed portions to form a resist. The circuit width and the space between conductors were 0.15 mm, respectively.
The resist formed substrate was dipped in a solution containing 55 g of CrO 2 and 210 ml cf concentrated H 2 SO 4 and diluted with water to make a total volume 1 liter at 55° C. for 10 minutes to chemically roughen circuit forming portions selectively, followed by washing with water and neutralization.
The resulting substrate was dipped in an electroless nickel/tungsten alloy plating solution comprising:
______________________________________nickel sulfate 7 g/litersodium tungstate 35 g/litersodium citrate 20 g/litersodium hypophosphite 10 g/liter______________________________________ with pH 9.8 at 93° C. for 60 minutes to form alloy plated layers of about 2 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist.
After washing with water, the substrate was dipped in the same electroless copper plating solution as used in Example 1 at 70° C. to form copper plated layers of about 20 μm thick. A solder resist was screen printed on both surfaces of the substrate except for the through-holes and cured with heating to give a sample of printed wiring board.
EXAMPLE 13
On a glass cloth-epoxy resin laminate containing palladium chloride (LE-168, a trade name, mfd. by Hitachi Chemical Co., Ltd.), the same adhesive as used in Example 12 was coated and cured with heating to form adhesive layers.
After drilling through-holes at predetermined positions using a high speed drilling machine, the substrate was laminated with a photoresist film for electroless plating (Photec SR-3000) using a vacuum laminator, exposed to light and developed to form resists on non-circuit portions.
The resist formed substrate was dipped in a solution containing 55 g of CrO 2 and 210 mL of concentrated H 2 SO 4 and diluted with water so as to make a total volume 1 liter at 55° C. for 10 minutes to chemically roughen circuit forming portions selectively, followed by washing with water and neutralization.
Then, the resulting substrate was dipped in an electroless cobalt/nickel alloy plating solution comprising
______________________________________cobalt chloride 30 g/liternickel chloride 30 g/litersodium glycolate 100 g/litersodium hypophosphite 22 g/liter______________________________________
with pH 4.5-5.0 at 92° C. for 50 minutes to form alloy plated layers of about 10 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist.
After washing with water, the substrate was dipped in the same electroless copper plating solution as used in Example 1 at 70° C. to form copper plated layers of about 20 μm thick on the alloy plated layers. A solder resist was screen printed on both surfaces of the resulting substrate except for the through-holes and cured with heating to give a sample of printed wiring board.
EXAMPLE 14
On a glass cloth-epoxy resin laminate containing palladium chloride (LE-168), the same adhesive as used in Example 12 was coated and cured with heating to form adhesive layers.
After drilling through-holes at predetermined positions using a high speed drilling machine, the substrate was laminated with a photoresist film for electroless plating (Photec SR-3000) using a vacuum laminator, exposed to light and developed to form resists on non-circuit portions.
The resist formed substrate was dipped in a solution containing 55 g of CrO 2 and 210 ml of concentrated H 2 SO 4 and diluted with water so as to make a total volume 1 liter at 55° C. for 10 minutes to chemically roughen circuit forming portions selectively, followed by washing with water and neutralization.
Then, the resulting substrate was dipped in an electroless cobalt plating solution comprising
______________________________________cobalt chloride 35 g/litersodium citrate 116 g/litersodium hypophosphite 11.5 g/liter______________________________________
with pH 8.0-10.0 at 90° C. for 60 minutes to form cobalt plated layers of about 5 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist.
After washing with water, the substrate was dipped in the same electroless copper plating solution as used in Example 1 at 70° C. to form copper plated layers of about 20 μm thick on the cobalt plated layers. A solder resist was screen printed on both surfaces of the resulting substrate except for the through-holes and cured with heating to give a sample of printed wiring board.
EXAMPLE 15
On a glass cloth-epoxy resin laminate containing palladium chloride (LE-168), the same adhesive as used in Example 12 was coated and cured with heating to form adhesive layers.
After drilling through-holes at predetermined positions using a high speed drilling machine, the substrate was laminated with a photoresist film for electroless plating (Photec SR-3000) using a vacuum laminator, exposed to light and developed to form resists on non-circuit portions.
The resist formed substrate was dipped in a solution containing 55 g of CrO 2 and 210 ml of concentrated H 2 SO 4 and diluted with water so as to make a total volume 1 liter at 55° C. for 10 minutes to chemically roughen circuit forming portions selectively, followed by washing with water and neutralization.
Then, the resulting substrate was dipped in an electroless palladium plating solution comprising
______________________________________tetramine palladium chloride 7.5 g/literEDTA-2Na 8.0 g/literammonia water 280 g/literhydrazine (1 mole/liter) 8 ml/liter______________________________________ at 38° C. for 60 minutes to form palladium plated layers of about 1 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist.
After washing with water, the substrate was dipped in the same electroless copper plating solution as used in Example 1 at 70° C. to form copper plated layers of about 20 μm thick on the palladium plated layers. A solder resist was screen printed on both surfaces of the resulting substrate except for the through-holes and cured with heating to give a sample of printed wiring board.
EXAMPLE 16
On a glass cloth-epoxy resin laminate containing palladium chloride (LE-168), the same adhesive as used in Example 12 was coated and cured with heating to form adhesive layers.
After drilling through-holes at predetermined positions using a high speed drilling machine, the substrate was laminated with a photoresist film for electroless plating (Photec SR-3000) using a vacuum laminator, exposed to light and developed to form resists on non-circuit portions.
The resist formed substrate was dipped in a solution containing 55 g of CrO 2 and 210 ml of concentrated H 2 SO 4 and diluted with water so as to make a total volume 1 liter at 55° C. for 10 minutes to chemically roughen circuit forming portions selectively, followed by washing with water and neutralization.
Then, the resulting substrate was dipped in an electroless gold plating solution comprising
______________________________________potassium cyanoaurate 2 g/literammonium chloride 75 g/litersodium citrate 50 g/litersodium hypophosphite 10 g/liter______________________________________
with pH 7.0-7.5 at 92° C. for 30 minutes to form plated layers of about 0.5 μm thick. After electroless nickel plating, a photoresist film for electroless plating made of ultraviolet curable acrylic resin (Photec SR-3000, a trade name, mfd. by Hitachi Chemical Co., Ltd.) was laminated on the resulting substrate using a vacuum laminator, followed by exposing to light and development to form a second resist on the nickel circuit 5 to 10 μm narrower than the first resist.
After washing with water, the substrate was dipped in the same electroless copper plating solution as used in Example 1 at 70° C. to form copper plated layers of about 20 μm thick on the plated layers. A solder resist was screen printed on both surfaces of the resulting substrate except for the through-holes and cured with heating to give a sample of printed wiring board.
COMPARATIVE EXAMPLE 9
The process of Example 12 was repeated except for not conducting the electroless nickel/tungsten alloy plating to give a sample of printed wiring board.
COMPARATIVE EXAMPLE 10
The process of Example 13 was repeated except for not conducting the electroless cobalt/nickel alloy plating to give a sample of printed wiring board.
In the above-mentioned samples of Examples 12 to 16 and Comparative Examples 9 and 10, both the conductor width and the space between conductors were made 0.1 mm, the through-hole diameter was made 0.6 mm, and the number of through-holes was made 200. Conductor patterns were made in the same manner as described in Examples 1 to 3.
Electrolytic corrosion (EC) between conductors, and between through-holes (generation of dendrite), solder heat resistance and peeling strength were measured in the same manner as described in Examples 1 to 3.
The results are shown in Table 3.
TABLE 3__________________________________________________________________________ Examples Comparative Examples 12 13 14 15 16 9 10__________________________________________________________________________EC betweenelectrodesafter 100 hrs No change No change No change No change No change Resistance No change value was reduced by 50%after 300 hrs No change No change No change No change No change Short- Short- circuited circuitedEC between No change No change No change No change No change Migration Migrationthrough-holes of copper of copperafter 300 hrsSolder heat ≧60 sec. ≧60 sec. ≧60 sec. ≧60 sec. ≧60 sec. ≧60 sec. ≧60 sec.resistance (260° C.)Peeling 2.1 2.1 2.1 1.8 1.9 2.0 2.1strength (kgf/cm)__________________________________________________________________________
As is clear from Table 3, both the electrolytic corrosion between conductors and between through-holes are improved remarkably, while maintaining good solder heat resistance and peeling strength.
EXAMPLE 17
Using the wiring board obtained n Example 1, the test was carried out under a relative humidity of 85%, a temperature of 85° C., and application of direct current of 100 V.
For comparison, a wiring board having a cross-sectional structure as shown in FIG. 2, wherein only one thick resist layer 8 is used in contact with a nickel layer 3 and a copper layer 4 at the boundary 10, was also subjected to the same test.
Using 500 samples, lowering of insulating resistance was measured and listed in the following Table 4.
TABLE 4______________________________________ Number of samples loweringTest the insulating resistanceExample hours shortNo. (hrs) >1 × 10.sup.10 ohm >1 × 10.sup.9 ohm circuited______________________________________Example 100 0 0 017 200 0 0 0 500 0 0 0 1000 0 0 0(Com- 100 0 0 0parison) 200 1 0 0 500 0 0 0 1000 5 6 2______________________________________
|
A process for producing a printed wiring board characterized by forming a nickel layer by electroless plating and a copper layer formed thereon by electroless plating, or forming a copper undercoating layer before the nickel layer by electroless plating can produce printed circuit boards excellent in resistance to electrolytic corrosion and suitable for mounting parts in high density.
| 7
|
BACKGROUND OF THE INVENTION
The present invention relates to a extremely sturdy and versatile torque limiting device adapted to be used in conjunction with any type of driver tool utilized for the rotational tightening of mechanical fasteners. More particularly, to an accurate torque limiting device designed to be used in a production environment where the driver it is matingly coupled to is operated pneumatically, hydraulicly or electrically at a high speed.
The proper operation of many mechanical components is, to a large degree, dictated by how the parts are assembled. Over tightening of mechanical fasteners can lead to cracked bodies, stretched and weakened bolts, stripped threads, smaller clearance tolerances, and a plethora of other maladies that can seriously affect the operation of the item in question. Similarly, under tightening of mechanical fasteners can have its own, different but potentially disastrous results. For this reason, where the tightness of a mechanical fastener is critical to the overall operation of the item, torque values are experimentally determined and assigned to the individual mechanical fasteners.
Conventional torque limiting devices are separate from the high speed production drivers used to tighten the fastener, and must be interchanged periodically as the desired torque value is approached. This slows the assembly process as conventional torque limiting devices require time to operate. Further, many of the conventional torque limiting devices (such as a torque wrench) indicate the torque level yet do not prevent that level from being exceeded.
The present device is an adjustable torque limiter that can be connected between a high speed driver and the bit that couples to and rotates the mechanical fastener. When the preset torque level is reached, the torque limiter goes into a free wheel mode therein disengaging the rotational drive force from the bit. In this mode the high speed driver may continue to rotate but the bit will remain stationary.
The adjustability of the torque limitation is accomplished by varying the amount of spring force by which a thrust disk (coupled to the high speed driver) frictionally rotates an upper torque body (coupled to the bit) through a intervening set of steel balls that are frictionally captured in an arced (or straight) depression formed in the underside of the upper torque body. When a certain preset torque limit that is being transmitted from the driver to the bit is exceeded, the upper torque body's rotation is retarded with respect to the lower torque body's rotation and the steel balls traverse downward and outwardly along separate arced and rearward ramped radial slots formed thereon a radial torque plate extending normally from the lower torque body, gradually depressing the spring and separating the radial torque plate of the lower thrust body from the thrust disc until the balls exit the distal end of their respective radial paths and enter the outer race of the upper torque body, wherein the bit and upper torque body go into a disengaged or free wheel mode. The unit is reset by a counter rotation of lower torque body with respect to the upper torque body so that the set of balls return to the proximate end of their radial paths in the radial torque plate.
Simply stated, the present torque limiter overcomes all of the stated deficiencies of the traditional prior art through the use of an adjustable force coupling system between the drive and driven ends of the unit. Henceforth, the present invention would fulfill a long felt need in the fabrication industry. This new invention utilizes and combines known and new technologies in a unique and novel configuration to overcome the aforementioned problems therein reducing assembly time and preventing unnecessary damage.
SUMMARY OF THE INVENTION
The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a torque limiter that is able to overcome the problems of the prior art and provide a failsafe method of quickly tightening mechanical fasteners in a production environment to a specified torque value.
It has many of the advantages mentioned heretofore and many novel features that result in a new and improved torque limiter which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art, either alone or in any combination thereof.
In accordance with the invention, an object of the present invention is to provide an improved adjustable torque limiter capable of use with a plethora of high speed drivers.
It is another object of this invention to provide an improved torque limiter capable of connection between a conventional mechanical driver and a conventional mechanical fastener bit.
It is a further object of this invention to provide an improved torque limiter capable of eliminating torque in excess of a desired preset value from being transmitted from a driver to the driven mechanical fastener.
It is still a further object of this invention to provide for an improved torque limiter capable of simple calibration.
It is yet a further object of this invention to provide an inexpensive torque limiter capable of accurate adjustment.
The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawings wherein like reference characters refer to like elements. Other objects, features and aspects of the present invention are discussed in greater detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front side exploded view of the improved adjustable torque limiter;
FIG. 2 is rear side exploded view of the improved adjustable torque limiter;
FIG. 3 is a side perspective view of the assembled improved adjustable torque limiter;
FIG. 4 is a side view of the improved adjustable torque limiter;
FIG. 5 is a front view of the improved adjustable torque limiter;
FIG. 6 is cross sectional view of the improved adjustable torque limiter taken through section A-A of FIG. 4 ;
FIG. 7 a is a front view of the rear housing;
FIG. 7 b is a side phantom view of the rear housing;
FIG. 7 c is a rear view of the rear housing;
FIG. 8 a is a front view of the rear bearing race ring;
FIG. 8 b is a side cross sectional view of the rear bearing race ring;
FIG. 8 c is a side phantom view of the rear bearing race ring;
FIG. 8 d is a rear view of the rear bearing race ring;
FIG. 9 a is a front view of the torque adjuster plate;
FIG. 9 b is a side view of the torque adjuster plate;
FIG. 9 c is a top view of the torque adjuster plate;
FIG. 9 d is a side cross sectional view of the torque adjuster plate;
FIG. 9 e is a rear view of the torque adjuster plate;
FIG. 10 a is a front view of the rear spring compression disk;
FIG. 10 b is a side view of the rear spring compression disk;
FIG. 10 c is a rear view of the rear spring compression disk;
FIG. 11 a is a front view of the compression spring;
FIG. 11 b is a side view of the compression spring;
FIG. 11 c is a rear view of the compression spring;
FIG. 12 a is a front view of the front spring compression disk;
FIG. 12 b is a side view of the front spring compression disk;
FIG. 12 c is a rear view of the front spring compression disk;
FIG. 13 a is a front view of the wear disk;
FIG. 13 b is a side view of the wear disk;
FIG. 13 c is a rear view of the wear disk;
FIG. 14 a is a front view of ring bearing;
FIG. 14 b is a side view of the ring bearing;
FIG. 14 c is a rear view of the ring bearing;
FIG. 15 a is a front view of the trust disk;
FIG. 15 b is a side view of the trust disk;
FIG. 15 c is a rear view of the trust disk;
FIG. 16 a is a top view of the lower torque body;
FIG. 16 b is a front view of the lower torque body;
FIG. 16 c is a side view of the lower torque body;
FIG. 16 d is a rear view of the lower torque body;
FIG. 17 is two series representations of torque ball positions within the lower torque body relative to the rotational slippage of the upper torque body;
FIG. 18 a is a top view of the upper torque body;
FIG. 18 b is a front view of the upper torque body;
FIG. 18 c is a side view of the upper torque body;
FIG. 18 d is a rear view of the upper torque body;
FIG. 19 a is a front view of the front housing;
FIG. 19 b is a side cross sectional view of the front housing;
FIG. 20 a is a front view of the front bearing race ring;
FIG. 20 b is a side view of the front bearing race ring; and
FIG. 20 c is a rear view of the front bearing race ring.
DETAILED DESCRIPTION
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated.
There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting.
In the most basic description, the torque limiter 2 is an encapsulated torque decoupling mechanism that has an upper driven body and a lower drive body coupled for unitary rotation by the frictional engagement of a set of balls residing partially in radial paths formed in a concavity of the upper driven body and partially in ramped and arced radial slots formed on a radial torque plate on the lower thrust body. The amount of friction or drag exerted by the balls (and thus the coupling force between the upper driven body and a lower drive body) is altered by adjusting the compression force that a fixed spring exerts via a thrust disk onto the balls. The adjustment of the spring and the rotation of the bodies within the encapsulation requires five sets of bearings and a plethora of structural elements. This friction or drag determines the amount of torque required to break apart the unitary rotation of the two bodies. Once this torque is exceed there is slippage between the upper and lower torque bodies forcing the balls to move downward and outward along their ramped and arced radial paths and into an outer race compressing the spring and allowing the balls to rotate around a stationary upper torque body. When this occurs the drive body is free to rotate uncoupled from the driven body. To accomplish unitary rotation again, the drive body rotation must stop and the drive body rotated slightly in a reverse rotation to reset the position of the set of balls in their paths.
A detailed explanation of the improved torque limiter 2 as well as the functionality and structure of all its components can best be seen by looking at FIGS. 1 and 2 . Here it is shown that the adjustable torque limiter 2 is made of a rear cylindrical housing 4 that constrains a lower outer race ring 6 affixed or formed at its proximate end. A set of lower housing balls 40 ( FIG. 6 ) affixes the lower housing 4 to an internally threaded torque adjuster plate 8 . The adjuster plate 8 contacts the rear spring location compression disk 10 which compresses spring 12 so as to exert a linear force upon front spring location compression disk 14 which is transmitted to the rear side 26 of the radial torque plate 29 of the lower torque body 22 through the wear disk 16 , bearing plate 18 and thrust disk 20 . Thrust balls 24 reside in ramped and arced radial slots 28 of the radial torque plate 29 so as lie between, yet simultaneously contact, thrust disk 20 and upper torque body 30 . Two sets of stabilizer balls 42 reside between lower torque body 22 and upper torque body 30 in two sets of conforming races so as to stabilize the upper torque body 30 when undergoing rotation movement relative to the lower torque body 22 . ( FIG. 6 ) Upper torque body 30 extends through front bearing outer race ring 34 which is affixed in the distal end of front cylindrical housing 32 . Upper housing balls 36 ( FIG. 6 ) separate yet connect upper torque body 30 to the front housing 32 by placement within groove 38 and a matingly engagable configuration in the front bearing outer race ring 34 . Front housing 32 is sized for sliding engagement over rear housing 4 so as to protect all the internal components and act as both a torque scale and a stationary surface to hold the improved torque limiter 2 as the internal components rotate.
Looking at FIG. 6 the placement of the five different sets of balls can best be seen. It is these balls that both connect and allow rotation between the various components. The thrust balls 24 rotationally couple the upper torque body 30 and the lower torque body 22 as well as allow decoupled rotation between the upper torque body 30 and the lower torque body 22 when the threshold torque limit has been reached. The two rows of stabilizer balls 42 connect yet allow rotation between the upper torque body 30 and the lower torque body 22 but more importantly, act to stabilize the longitudinal axis of the torque limiter 2 to minimize wear and wobble regardless of whether the threshold torque limit has been reached. The upper housing balls 36 connect yet allow the upper torque body 30 to rotate independently of the upper housing 32 and outer race ring 34 . The lower housing balls 40 allow the lower torque body 22 and the torque adjuster plate 8 to rotated independently of the lower housing 4 and lower outer race ring 6 while connecting the lower housing 4 to the torque adjuster plate 8 .
Additionally, three or more adjuster balls 44 (and optionally a locking pin) are secured in the rear spring location compression disk 10 . The torque adjuster plate 8 has a ring of equidistantly spaced detents 46 that matingly conform to the adjuster balls 44 . When the torque adjuster plate 8 is rotationally engaged with the threaded end of the lower torque body 22 so as to advance, the rear spring location compression disk 10 is also forced to advance up the threaded end of the lower torque body 22 . Since the rear spring location compression disk 10 has two internal tabs 48 that engage the two longitudinal broachways 50 cut along the threaded portion of the lower torque body 22 , the rear spring location compression disk 10 does not rotate relative to the lower torque body 22 . This allows the compression of the spring 12 without any twisting that would distort the compression profile of the spring 12 , and make the precise linear torque threshold indication impossible. The adjuster balls 44 reduce the friction between the torque adjuster plate 8 and the rear spring location compression disk 10 when the torque is being adjusted, and lock into the ring of equidistantly spaced detents 46 to prevent separation between the torque adjuster plate 8 and the rear spring location compression disk 10 when the torque adjuster plate 8 has been sufficiently advanced along the threaded end of the lower torque body 22 . It is also known that in an alternate embodiment not illustrated, a more positive engagement between the torque adjuster plate 8 and the rear spring location compression disk 10 could be accomplished through the use of a set or dog screw advancing through a threaded recess in the torque adjuster plate 8 so as to partially engage a matingly sized detent in the rear spring location compression disk 10 . This would serve to lock the torque adjuster plate 8 to the rear spring location compression disk 10 therein preventing any unwanted decompression of the spring 12 once the limiting torque has been set.
Since the various components of the torque limiter 2 are held together by balls, there are specific ways to get the balls into their desired locations. Although the thrust balls 24 may be manually inserted during assembly, and the adjuster balls 44 are permanently affixed into the rear spring location compression disk 10 , all other balls require insertion through partially threaded externally accessible passages that then are sealed by set screws or equivalent methods.
The lower housing balls 40 are inserted through first passage 52 ( FIGS. 6 and 10 ) in the torque adjuster plate 8 . This first passage 52 has an “L” path that begins on the torque adjuster plate rear face 54 and exits in torque adjuster plate groove 56 . When all the lower housing balls 40 have been inserted a set screw (not illustrated) is threadingly engaged into the first passage 52 to constrain the lower housing balls 40 .
The two sets of stabilizer balls 42 are inserted through second passage 58 and third passage 60 ( FIGS. 6 and 18 ) in the upper torque body 30 . These passages are defined by axial paths. When all the stabilizer balls 42 have been inserted, pins are inserted into the passages and lock rings 39 are engaged around a ring groove so as to constrain the pin and stabilizer balls 42 .
The upper housing balls 36 are inserted through fourth passage 62 ( FIGS. 6 and 13 20 ) in the front bearing 5 race ring 34 . This fourth passage 62 has an “L” path that begins on the front bearing race ring front face 64 and exits in the groove 38 . When all the upper housing balls 36 have been inserted a set screw (not illustrated) is threadingly engaged into the fourth 10 passage 62 .
Looking at FIGS. 3 and 4 , perspective views of the assembled torque limiter 2 , the decoupling torque scale 66 can be seen. This is a linear scale that coincides with the friction transmitted by the spring 12 , onto the thrust disk 20 the since the spring utilized has a linear coefficient throughout the range of spring compression utilized in the torque limiter 2 . The torque scale 66 simply reflects the relative position of the rear cylindrical housing 4 within the front cylindrical housing 32 since the rear cylindrical housing 4 is affixed to the torque adjuster plate 8 and compresses the spring 12 by threaded advancement along the threaded end of the lower torque body 22 . The scale 66 surrounds a slot 68 that allows better visual alignment of the edge of the rear cylindrical housing 4 with the scale 66 . As is well known in the art an adjustable indicator can be installed on the rear cylinder housing 4 or the torque scale 66 can be made to adjust its location on the front cylindrical housing 32 . It is also well known in the industry that the scale 66 could be placed on the lower housing 4 rather than the upper housing 32 , since it only measures the relative position of each of the housings with respect to each other (which is directly proportional to the amount of compression exerted by the spring 12 .)
FIG. 5 illustrates the front end of the torque limiter 2 . The proximate end of the upper torque body 30 and the socket engaging stud 98 can be seen extending through the front bearing race 34 . Although shown as a separate element, it is known that in an alternate embodiment the front bearing race 34 and upper housing 32 may be fabricated as a unitary element.
FIG. 7 a - c shows the rear cylindrical housing 4 wherein it can be seen that the stepped cylindrical configuration having a smaller diameter proximate end 72 and a larger diameter distal end 74 accommodates and constrains the lower outer race ring 6 . The lower outer race ring 6 has a circumferential groove 76 formed thereon to accept the lower housing balls 40 ( FIG. 8 a - d ) and a circumferential shoulder 78 that the outer torque adjuster plate flange 80 ( FIG. 9 a - e ) rests upon.
The torque adjuster plate 8 is an disk that is internally threaded so as to matingly engage the threaded end of the lower torque body 22 . There are two tool recesses 82 formed therein the distal face for the insertion of a pronged tool to rotate the torque adjuster plate 8 . There is also a first passage 52 to allow the lower housing balls 40 to be installed. On the proximate face there is a circular series of equidistant detents 46 formed to jointly receive the equidistantly spaced adjuster balls 44 which are pressed into accommodating recesses (not illustrated) in the rear spring location compression disk 10 ( FIG. 10 ).
To ensure that the spring 12 when compressed will not twist and adjust its linear spring coefficient, the rear spring location compression disk 10 has two internal tabs 48 that lock the rear spring location compression disk 10 to the lower torque body 22 , preventing rotation relative to the lower torque body 22 .
The spring 12 illustrated in FIG. 11 is a coil wound compression spring that has a linear spring coefficient across the range of compression utilized.
The front spring location compression disk 14 ( FIG. 12 ) is similar to the rear spring location compression disk 10 with the elimination of the adjuster balls 44 and their recesses. It is also designed to eliminate any spring twist with its own set of internal tabs 48 .
Looking at FIGS. 13-15 it can be seen that the wear disk 16 is a plain flat circular washer that acts as a replaceable smooth surface for the bearing plate 18 to act against. The bearing plate 18 is a conventional needle bearing disk that allows the rotation of the thrust disk 20 from the front spring location compression disk 14 . There is raised flange 84 on the thrust disk 20 that is sized to constrain the bearing plate 18 so as to minimize any lateral movement.
The lower torque body 22 has a threaded distal end with two longitudinal broachways 50 cut along the threaded end. A radial torque plate 29 extends normally therefrom a forward section of the lower torque body. Into the torque plate 29 are ramped and counter clockwise arced radial slots 28 formed therethrough sized to slidingly accommodate thrust balls 24 . The torque plate distal face 86 is planar while the torque plate proximate face 88 is ramped. The ramp thickness of the torque plate 29 increases toward the center. The proximate end of the lower torque body 22 has two parallel and adjacent stabilizer grooves 90 that act as inner races for sets of stabilizer balls 42 . ( FIG. 2 ) In the distal end of the lower torque body 22 there is a square recess 92 sized to accommodate a rotating power driver such as a pneumatic ratchet, although any configured recess or boss that matingly conforms to the configuration of the driver can be utilized.
Referring now to FIG. 18 a - d the upper torque body 30 has a dished or concave distal end with grooved, clockwise arced radial paths 94 tapering deeper toward its center. The center of the distal end has a blind orifice 96 to accommodate the proximate end stub shaft 99 of the lower torque body 22 , and has two stabilizer tracks 38 ( FIG. 2 ) that act as outer races for sets of stabilizer balls 42 . Second passage 58 and third passage 60 are defined by axial paths in the upper torque body 30 . The proximate end of the upper torque body 30 has groove 38 and a socket engaging stud 98 formed thereon.
FIGS. 19 a and b shows the front cylindrical housing 32 wherein it can be seen that the proximate end has a front bearing race recess 100 to accommodate and constrain the front bearing race 34 . The front bearing race 34 has a circumferential groove 102 formed thereon to accept the upper housing balls 36 . ( FIG. 6 )
It is important to note that the upper torque body's radial paths 94 are arced in the opposite direction from the radial slots 28 formed in the radial torque plate 29 of the lower torque body 22 . It is this clockwise-counterclockwise arced relationship that forces the thrust balls 24 into their outer position when the upper torque body 30 and the lower torque body 22 are decoupled (no longer frictionally engaged). Conversely, when the innermost segments of the radial slots 28 and radial paths 94 are aligned, the thrust balls 24 are constrained in their center most location and frictional engagement is achieved.
The operation of the torque limiter 2 is best understood looking at looking at FIG. 1 and the two series depicted in FIG. 17 a - f . A two pronged fork wrench, as is well known in the mechanical arts, is inserted into the tool recesses 82 on the distal face of the torque adjuster plate 8 and is rotated to advance the torque adjuster plate 8 up (or down) the threaded end of the lower torque body 22 until the desired maximum torque is indicated on the torque scale 66 . The torque adjuster plate 8 also advances the rear housing 4 relative to the front housing 32 as they are connected by lower housing balls 40 . Adjustment will be in uniform increments set by the engagement of the adjuster balls 44 of the rear spring compression disk 10 into the detents 46 on the proximate face of the torque adjuster plate 8 . As the torque adjuster plate 8 rotationally advances up the lower torque body 22 it linearly advances the rear spring location compression disk 10 so as to compress spring 12 and increase the linear force transmitted to the thrust disk 20 through the front spring location compression disk 14 , the wear disk 16 and bearing plate 18 . The thrust disk 20 transmits an upward linear force upon the thrust balls 24 which are constrained at the alignment of the center most point of the radial torque plate's radial slots 28 and the upper torque body's radial paths 94 as illustrated in FIG. 17 c . This alignment is achieved when the radial torque plate 29 and the upper torque body 30 are in the relative positions as shown in FIGS. 17 a and b . Here approximately one half of the thrust balls 24 resides within the radial paths 94 . As the lower torque body 22 is rotated the friction or drag of the thrust balls 24 on the thrust disk 20 and the inwardly tapered center most point of the upper torque body's radial paths 94 causes a corresponding rotation of the upper torque body 30 .
When the limiting torque is reached, the application of more torque exceeds this frictional engagement and causes slippage between the upper torque body 30 and the lower torque body 22 . With the rotation of the upper torque body 30 retarded ( FIGS. 17 d and e ) the thrust balls 24 are forced along their radial paths 94 by the sides of the radial slots 28 compressing the spring 12 and increasing the distance between the thrust disk 20 and the radial torque plate 29 . As the thrust balls continue moving along the radial slots 28 and the radial paths 94 , the thrust balls 24 reach the free wheeling race 110 of the upper torque body 30 at which time the rotation of the upper torque body 30 ceases despite the rotation of the lower torque body 22 . This is illustrated in FIG. 17 f . The rotational retardation of the upper torque body 30 relative to the torque plate 29 that is required to force the thrust balls 24 into the free wheeling race 110 is approximately 60 degrees (in a six path torque limited) as illustrated in FIGS. 17 d and e . The location of the thrust balls 24 in the radial torque plate 29 when the upper torque body 30 and lower torque body are frictionally engages is shown in FIG. 17C . The location of the thrust balls 24 in the radial torque plate 29 when the upper torque body 30 and lower torque body are decoupled is shown in FIG. 17F .
To reset the torque limiter 2 requires an advancement of the upper torque body 32 by approximately 60 degrees relative to the position of the radial torque plate 30 so that thrust balls 24 can be forced back along the radial slots 28 until the thrust balls 24 are returned to the centermost position of the radial paths 94 . Since the lower torque body 22 is separated from the rear cylindrical housing 4 by lower housing balls 40 , and since the upper torque body 30 is separated from the front cylindrical housing 32 by the upper housing balls 36 , the device's outer housing is rotationally independent and may be held by the operator's hand while the torque limiter is operated.
The above description will enable any person skilled in the art to make and use this invention. It also sets forth the best modes for carrying out this invention. There are numerous variations and modifications thereof that will also remain readily apparent to others skilled in the art, now that the general principles of the present invention have been disclosed. For example the number and shapes of the radial slots 28 and the radial paths 94 as well as their clockwise and counterclockwise arc directions. It is also known that the arced depressions formed in the upper housing may be straight depressions as it is the arc in the torque plate that forces the thrust balls into the decoupled position. It is also known that more than one spring may be used. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
|
An adjustable torque limiter that can be coupled between a high speed driver and the socket that rotates a mechanical fastener. When a preset torque level is reached, the torque limiter disengages the rotational drive force from the bit. The adjustability of the torque limitation is accomplished by varying the amount of spring force by which a thrust plate (coupled to the high speed driver) is forced against a set of steel balls residing in slots of a radial torque plate and in a set of paths formed in a concavity of an upper torque body (coupled to the driven socket engaging stud). When a certain preset torque is transmitted from the driver to the socket, the steel balls traverse outward along the separate arced ramp radial paths therein the upper torque body until the balls enter an annular race that allows the thrust plate to go into a disengaged or free wheel mode from the upper torque body.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Patent Application No. 60/724,183 filed Oct. 6, 2005, which is hereby incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention is related to operating a four-stroke internal combustion engine.
BACKGROUND OF THE INVENTION
[0003] The automotive industry is continually researching new ways of improving the combustion process of the internal combustion engine in an effort to improve fuel economy, meet or exceed emission regulatory targets, and to meet or exceed consumer expectations regarding emissions, fuel economy and product differentiation.
[0004] Most modem conventional internal combustion engines attempt to operate around stoichiometric conditions. That is to say providing an optimal air/fuel ratio of substantially 14.6 to 1 that results in substantially complete consumption of the fuel and oxygen delivered to the engine. Such operation allows for exhaust gas aftertreatment by 3-way catalysts which clean up any unconsumed fuel (HC) and combustion byproducts such as nitrogen oxides (NO x ) and carbon monoxide (CO). Most modern engines are fuel injected having either throttle body injection (TBI) or multi-port fuel injection (MPFI) wherein each of a plurality of injectors is located proximate an intake port at each cylinder of a multi-cylinder engine. Better air/fuel ratio control is achieved with a MPFI arrangement; however, conditions such as wall wetting and intake runner dynamics limit the precision with which such control is achieved. Fuel delivery precision can be improved by direct in-cylinder injection (DI). So called linear oxygen sensors provide a higher degree of control capability and, when coupled with DI, suggest an attractive system with improved cylinder-to-cylinder air/fuel ratio control capability. However, in-cylinder combustion dynamics then become more important and combustion quality plays an increasingly important role in controlling emissions. As such, engine manufacturers have concentrated on such things as injector spray patterns, intake swirl, and piston geometry to effect improved in-cylinder air/fuel mixing and homogeneity.
[0005] While stoichiometric gasoline four-stroke engine and 3-way catalyst systems have the potential to meet ultra-low emission targets, efficiency of such systems lags behind so-called lean-burn systems. Lean-bum systems also show promise in meeting emission targets for NO x through combustion controls, including high exhaust gas dilution and emerging NO x aftertreatment technologies. However, lean-burn systems still face other hurdles, for example, combustion quality and combustion stability particularly at part load operating points and high exhaust gas dilution.
[0006] Lean-bum engines, at a most basic level, include all internal combustion engines operated with air in excess of that required for the combustion of the fuel charge provided. A variety of fueling and ignition methodologies differentiate lean-bum topologies. Spark ignited systems (SI) initiate combustion by providing an electrical discharge in the combustion chamber. Compression ignition systems (CI) initiate combustion with combustion chamber conditions including combinations of air/fuel ratio, temperature and pressure among others. Fueling methods may include TBI, MPFI and DI. Homogeneous charge systems are characterized by very consistent and well vaporized fuel distribution within the air/fuel mixture as may be achieved by MPFI or direct injection early in the intake cycle. Stratified charge systems are characterized by less well vaporized and distributed fuel within the air/fuel mixture and are typically associated with direct injection of fuel late in the compression cycle.
[0007] Known gasoline DI engines may selectively be operated under homogeneous spark ignition or stratified spark ignition modes. A homogeneous spark ignited mode is generally selected for higher load conditions while a stratified spark ignition mode is generally selected for lower load conditions.
[0008] Certain DI compression ignition engines utilize a substantially homogeneous mixture of hot air and fuel and establish pressure and temperature conditions during engine compression cycles that cause ignition without the necessity for additional spark energy. This process is sometimes called controlled auto-ignition or homogeneous charge compression ignition (HCCI). Controlled auto-ignition and HCCI may be used interchangeably. Controlled auto-ignition is a predictable process and thus differs from undesirable pre-ignition events sometimes associated with spark-ignition engines. Controlled auto-ignition also differs from well-known compression ignition in diesel engines wherein fuel ignites substantially immediately upon injection into a highly pre-compressed, high temperature charge of air, whereas in the controlled auto-ignition process the hot air and fuel are mixed together prior to combustion during intake events and generally at compression profiles consistent with conventional spark ignited four-stroke engine systems.
[0009] Four-stroke internal combustion engines have been proposed which provide for auto-ignition by controlling the motion of the intake and exhaust valves associated with a combustion chamber to ensure that an air/fuel charge is mixed with combusted gases to generate conditions suitable for auto-ignition without the necessity for externally pre-heating intake air or cylinder charge or for high compression profiles. In this regard, certain engines have been proposed having a cam-actuated exhaust valve that is closed significantly later in the four-stroke cycle than is conventional in a spark-ignited four-stroke engine to allow for substantial overlap of the open exhaust valve with an open intake valve whereby previously expelled combusted gases are drawn back into the combustion chamber early during the intake cycle. Certain other engines have been proposed that have an exhaust valve that is closed significantly earlier in the exhaust cycle thereby trapping combusted gases for subsequent mixing with fuel and air during the intake cycle. In both such engines the exhaust and intake valves are opened only once in each four-stroke cycle. Certain other engines have been proposed having the exhaust valve opened twice during each four-stroke cycle—once to expel combusted gases from the combustion chamber into the exhaust passage during the exhaust cycle and once to draw back combusted gases from the exhaust passage into the combustion chamber late during the intake cycle. These engines variously utilize throttle body, port or direct combustion chamber fuel injection.
[0010] However advantageous such lean-bum engine systems appear to be, certain shortfalls with respect to combustion quality and combustion stability, particularly at part load operating points and high exhaust gas dilution, continue to exist. Such shortfalls lead to undesirable compromises including limitations on how much a fuel charge can effectively be reduced during part load operating points while still maintaining acceptable combustion quality and stability characteristics. As a further complicating factor, variations in commercially available fuels can also have pronounced effects upon combustion stability, particularly at low load operating regions.
SUMMARY OF THE INVENTION
[0011] A lean-bum, four-stroke, internal combustion engine is generally desirable. Furthermore, such an engine exhibiting high combustion stability at part load operating points is desirable. Moreover, such an engine capable of extended lean operation into heretofore unattained part load operating point regions is desirable.
[0012] The present invention relates to a method for robust homogeneous charge compression ignition control using commercially available fully-blended gasoline fuels with wide range of octane qualities. Using combinations of variable valve actuation and fuel injection, the controlled auto-ignition combustion is robust at all engine-operating conditions examined with the present invention.
[0013] The present invention provides these and other desirable aspects in a method of operating a four-stroke internal combustion engine with extended capability at low engine loads while maintaining or improving combustion quality, combustion stability and engine out emissions, particularly in light of variability of commercial fuels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0015] FIG. 1 is a schematic illustration of a single-cylinder, direct-injection, four-stroke internal combustion engine;
[0016] FIG. 2 illustrates percent of samples as a function of OI with K=2.0 for regular, intermediate, and premium gasoline fuels in North America including summer and winter periods;
[0017] FIG. 3 illustrates crank angle position of 50% burned (CA 50 ) versus NVO for the test fuels at 8 mg/cycle during NVO sweep;
[0018] FIG. 4 illustrates a plot of crank angle position of 10% burned (CA 10 ) against crank angle position of 50% burned (CA 50 ) for the test fuels at 8 mg/cycle during NVO sweep;
[0019] FIG. 5 illustrates COV of IMEP versus crank angle position of 50% burned (CA 50 ) for the test fuels at 8 mg/cycle during NVO sweep;
[0020] FIG. 6 illustrates measured Net Mean Effective Pressure (NMEP) versus crank angle position of 50% burned (CA 50 ) for the test fuels at 8 mg/cycle during NVO sweep;
[0021] FIG. 7 illustrates NVO requirement for all the fuels tested at 8 mg/cycle such that CA 50 is maintained at 4 degrees after top dead center (aTDC) combustion;
[0022] FIG. 8 illustrates crank angle position of 50% burned (CA 50 ) versus NVO for the test fuels at 14 mg/cycle during NVO sweep;
[0023] FIG. 9 illustrates NVO requirement for optimal CA 50 of all the fuels tested at 8 and 14 mg/cycle;
[0024] FIG. 10 illustrates recompression burned fuel as a function of recompression injected mass for both Fuel A and Fuel E at hot idle—5.5 mg/cycle;
[0025] FIG. 11 illustrates CA 50 @ NVO=170 deg. as a function of octane index (OI) with K=2.1 for all the test fuels at 8.0 mg/cycle;
[0026] FIG. 12 illustrates CA 50 @ NVO=130 deg. as a function of OI with K=1.9 for all the test fuels at 14 mg/cycle;
[0027] FIG. 13 illustrates a schematic control diagram with which robust controlled auto-ignition combustion is maintained with variations in fuel octane qualities; and
[0028] FIG. 14 schematically illustrates a preferred embodiment of a control scheme utilizing valve control and fuel timing/quantity control to effect desired combustion phasing in the presence of fuel variability in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] With reference first to FIG. 1 , an exemplary single cylinder four-stroke internal combustion engine system (engine) 10 suited for implementation of the present invention is schematically illustrated. It is to be appreciated that the present invention is equally applicable to a multi-cylinder four-stroke internal combustion engine. The present exemplary engine 10 is shown configured for direct combustion chamber injection (direct injection) of fuel vis-à-vis fuel injector 41 . Alternative fueling strategies including port fuel injection or throttle body fuel injection may also be used in conjunction with certain controlled auto-ignition engines; however, the preferred approach is direct injection. Similarly, while widely available grades of gasoline and light ethanol blends thereof are preferred fuels, alternative liquid and gaseous fuels such as higher ethanol blends (e.g. E 80 , E 85 ), neat ethanol (E 99 ), neat methanol (M 100 ), natural gas, hydrogen, biogas, various reformates, syngases etc. may also be used in such engines.
[0030] With respect to the base engine, a piston 11 is movable in a cylinder 13 and defines therein a variable volume combustion chamber 15 . Piston 11 is connected to crankshaft 35 through connecting rod 33 and reciprocally drives or is reciprocally driven by crankshaft 35 . Engine 10 also includes valve train 16 illustrated with a single intake valve 21 and a single exhaust valve 23 , though multiple intake and exhaust valve variations are equally applicable for utilization with the present invention. Valve train 16 also includes valve actuation apparatus 25 which may take any of a variety of forms including electrically controlled hydraulic or electromechanical actuation (a.k.a. fully flexible valve actuation, FFVA). Alternative valve actuation apparatus adaptable for implementation in conjunction with the present invention include multi-profile cams (a.k.a. multi-lobe, multi-step) and selection mechanisms, cam phasers and other mechanically variable valve actuation technologies implemented individually or in combination. A two-step with dual cam phasing valvetrain suitable for effecting the valve controls disclosed herein includes first exhaust and intake cams for effecting nominal duration and lift profiles, second exhaust and intake cams for effecting more limited duration and lift profiles and dual, independent cam phasers. Intake passage 17 supplies air into the combustion chamber 15 . The flow of the air into the combustion chamber 15 is controlled by intake valve 21 during intake events. Combusted gases are expelled from the combustion chamber 15 through exhaust passage 19 with flow controlled by exhaust valve 23 during exhaust events. Spark plug 29 is used to enhance the ignition timing control of the engine at certain conditions (e.g. during cold start and near the low load operation limit). Also, it has proven preferable to rely on spark ignition near the high part-load operation limit under controlled auto-ignition combustion and during high speed/load operating conditions with throttled or non-throttled SI operation.
[0031] Engine control is provided by computer based control 27 which may take the form of conventional hardware configurations and combinations including powertrain controllers, engine controllers and digital signal processors in integrated or distributed architectures. In general, control 27 includes at least one microprocessor, ROM, RAM, and various I/O devices including A/D and D/A converters and power drive circuitry. Control 27 also specifically includes controls for valve actuation apparatus 25 , fuel injector 41 and spark plug 29 . Controller 27 includes the monitoring of a plurality of engine related inputs from a plurality of transduced sources including engine coolant temperature, outside air temperature, manifold air temperature, operator torque requests, ambient pressure, manifold pressure in throttled applications, displacement and position sensors such as for valve train and engine crankshaft quantities, cylinder pressure, exhaust gas constituents and further includes the generation of control commands for a variety of actuators as well as the performance of general diagnostic functions. Known cylinder pressure sensors may sense combustion pressure directly, e.g. via intrusive or non-intrusive pressure sensors, or indirectly e.g. via ion sensing or crankshaft torque. While control and power electronics associated with valve actuation apparatus 25 , fuel injector 41 and spark plug 29 may be integral with control 27 , such may also be incorporated as part of distributed smart actuation scheme wherein certain monitoring and control functionality related to respective subsystems are implemented by programmable distributed controllers associated with such respective valve, fuel control and spark subsystems.
[0032] A total of 7 different fuels (designated as Fuel A to Fuel G) were tested using the exhaust recompression valve strategy at three different load conditions of 5.5, 8.0 and 14 mg/cycle. The three fueling/loads cover all three HCCI combustion modes: lean with split injection as disclosed for example in commonly assigned U.S. Pat. No. 6,971,365 B 1, lean with single injection as disclosed for example in commonly assigned U.S. Ser. No. 10/899,457 (2006/0016423), and stoichiometric with split injection as disclosed for example in commonly assigned U.S. Pat. No. 6,994,072 B2.
[0033] It is well known and accepted that Research and Motor Octane Numbers (RON and MON) alone do not adequately describe knocking (auto-ignition) behavior of commercial fuels in traditional spark-ignition engines. A combination of them, (RON+MON)/2, called octane number, however, was used in common practice to rank the anti-knock quality of a practical fuel.
[0034] In 2001, Kalghatgi of Shell Research proposed an octane index (OI) to better describe the fuels knocking behavior in accordance with the following relationships.
OI=RON−K*S where S (sensitivity)= RON−MON (1)
or
OI =(1 −K ) RON+K MON (2)
[0035] Kalghatgi showed good linear correlation between knock-limited spark advance and OI in a single cylinder engine, and acceleration times and OI in knock sensor equipped vehicles.
[0036] In 2003, Kalghatgi extended his K factor analysis to HCCI engines showing good correlation between CA 50 and OI at the following engine conditions.
[0037] CR=16.7 and 13.6,
[0038] PIVC=1 & 2 bar,
[0039] several TIVC,
[0040] several lambdas,
[0041] 4 speeds,
[0042] 11 different fuels, and
[0043] K values ranged from −1.90 to 0.41.
[0044] In 2003, Kalghatgi extended his K factor analysis further to include Shell's HCCI engine running at higher intake temperatures and included more “gasoline” like fuels. The following engine conditions correspond to this engine.
[0045] Single cylinder,
[0046] PFI,
[0047] fixed cams,
[0048] no EGR,
[0049] CR=14.0,
[0050] PIVC=1 bar,
[0051] 3 TIVC,
[0052] several lambdas,
[0053] 3 speeds, and
[0054] 12 different fuels (4-PRF's, 3-toluene/hexane blends, 4-refinery blending components, one fully blended gasoline).
[0055] In summary, according to Kalghatgi's “K” factor analysis, the auto-ignition quality of a practical fuel can be correlated using the octane index, OI=RON−K*(RON−MON) where RON and MON are the Research and Motor Octane Numbers. K is a constant depending only on the pressure and temperature variation in the engine and varies with engine design parameter such as compression ratio. K decreases as the compression temperature in the unburned gas at a given pressure in the engine decreases and can be negative if this temperature is lower than in the RON test.
[0056] A four-stroke, single cylinder, 0.55 liter, controlled auto-ignition, gasoline direct injection internal combustion engine was utilized in implementing the valve and fueling controls and acquisition of the various data embodied herein. Unless specifically discussed otherwise, all such implementations and acquisitions are assumed to be carried out under standard conditions as understood by one having ordinary skill in the art.
[0057] Having thus described the environment and certain application hardware suitable for implementing the present invention, attention is now directed toward FIG. 2 . FIG. 2 shows the plot of percent of North America sampled fuels including during summer and winter periods against octane index (OI=RON−K*(RON−MON)) with K=2 (The reason for choosing 2 will be explained later). A total of 1870 samples were collected that includes regular, intermediate, and premium grade gasoline. Our test fuels, Fuel D, Fuel A, and Fuel E are indicated which covered wide OI range of the sampled fuels.
[0058] FIG. 3 shows the variations in CA 50 as a function of NVO for all the test fuels at 8 mg/cycle. It can be seen from the figure that CA 50 advances near linearly with increasing NVO. In particular, a 20-degree-increase in NVO resulted in 4-degree-advance in CA 50 . In addition, our base fuel, Fuel A, shows a CA 50 -NVO relationship representative of the average of all fuels tested.
[0059] Further, for fixed CA 50 , ±10 degrees spread in NVO is observed for all the fuels tested. In other words, a NVO authority of ±10 degrees centered at NVO=160 deg. is sufficient in maintaining the optimal combustion phasing at 8 mg/cycle independent of fuel.
[0060] When all the performance and emissions data are plotted against the crank angle position of 50% mass burned (CA 50 ), they collapsed into a single curve irrespective of the test fuels used. Typical examples are shown in FIGS. 4-6 for CA 10 , COV of IMEP, and NMEP, respectively. In particular, ±2 degrees variations in CA 50 centered about the optimal value at 4 degrees aTDC results in less than 1% reduction in NMEP. In other words, the change in NMEP with CA 50 is minimal for combustion phasings near the optimal value. Thus, for practical applications, a 10 degrees NVO spread (160±5 degrees) is sufficient in order to control NMEP within 1%
[0061] The required NVO for optimal combustion phasing at 4 degrees aTDC combustion is shown in FIG. 7 for all the test fuels. It can be seen from the figure that Fuel E has the most stringent NVO requirement.
[0062] FIG. 8 shows the variations in CA 50 as a function of NVO for all the test fuels at a fuel level of 14 mg/cycle. It can be seen from the figure that: 1) CA 50 advances near linearly with increasing NVO. In particular, 10 degrees increase in NVO resulted in 6 degrees advance in CA 50 . The sensitivity between CA 50 and NVO is higher for 14 mg/cycle than 8 mg/cycle. 2) For fixed CA 50 at 8 degrees aTDC, ±7 degrees spread in NVO is observed for all the fuels tested. 3) A NVO authority of ±7 degrees is needed to account for all the test fuel tested.
[0063] The required NVO for optimal CA 50 is shown in FIG. 9 for all the test fuels at 8 and 14 mg/cycle test points. In general, the fuels with higher required NVO at 8 mg/cycle demand higher NVO at 14 mg/cycle as well. Further, a consistent relationship exists between the NVO requirements at 8 and 14 mg/cycle in order to maintain best combustion phasing and hence engine performance. Knowing the required changes at one fueling level will be sufficient to make the necessary changes at all fueling levels. Among all the fuel tested at 8 mg/cycle, Fuel E requires the largest NVO to reach optimal combustion phasing at 4 degrees aTDC. It is about 175 degrees ( FIG. 7 ) which is very close to the upper limit of hydraulic cam phaser operation of 190 degrees. To mitigate the requirement on NVO for combustion phasing control, Fuels A and E were used for injection strategy study to demonstrate the effectiveness of using injection timing and quantity for combustion phasing control. To this end, both single and split injection strategies were evaluated. In particular, FIG. 10 shows that the recompression burned fuel increases with increasing recompression injected fuel, which resulted in higher mixture gas temperature during compression and hence combustion phasing advance. However, its effectiveness decreases with increasing recompression injected fuel beyond 2 mg.
[0064] The Applicants have resolved the above results to suggest the following procedure for steady-state HCCI engine combustion phasing control to account for fuel variations between 7 and 15 mg/cycle (180-450 kPa NMEP).
[0065] 1. A nominal NVO is selected first depending on the load level ( FIG. 9 ).
[0066] 2. Desired CA 50 is then specified.
[0067] 3. Adjust NVO±/−5 deg. as required to maintain CA 50 within target range with different fuels.
[0068] 4. At the NVO limits adjust reforming fueling level as required to maintain CA 50 within target window.
[0069] FIG. 11 shows the experimentally measured CA 50 @ NVO=170 for all test fuels at 8 mg/cycle versus OI using k=2.1. Good linear correlation between CA 50 and OI is demonstrated. The same is true for the 14 mg/cycle test point. FIG. 12 shows our measured CA 50 @ NVO=130 for all test fuels at 14 mg/cycle versus OI using k=1.9. By comparing FIG. 12 to FIG. 11 , it is clear from both figures that different correlations exist for different loads. However, it is also clear from both figures that our data are well correlated by a single Kalghatgi K factor (˜2) at different loads.
[0070] The CA 50 —OI correlations shown in FIG. 11 and FIG. 12 are useable to predict how commercially available, fully-blended gasoline fuels (with known RON and MON) will behave in our HCCI engine. For example, using RON and MON of the fuel and a K valve equals 2, the CA 50 can be calculated at 8 mg/cycle using the following relationship.
CA 50=0.44 OI −30.9 (3)
[0071] Eq. (3) differs slightly from the correlation shown in FIG. 11 due to the use of a slightly different K value. The NVO required in order to move the CA 50 back to its optimal location (4 degrees aTDC) is calculated using the following relationship at 8 mg/cycle which is derived based on Fuel A data shown in FIG. 3 .
NVO =182−4.35 CA 50 (4)
[0072] Since higher octane indices ( 01 ) equate to delayed HCCI combustion phasing, fuels with higher octane indices will be challenging. Further, since OI=RON−2*Sensitivity, fuels with high RON and low Sensitivity will be the most challenging.
[0073] FIG. 13 illustrates schematically a control methodology for HCCI engine combustion phasing control to compensate for fuel variations substantially as follows.
[0074] 1. Primary load control parameter is NVO.
[0075] 2. Lookup table for NVO as function of load at fully warmed-up condition.
[0076] 3. Use combustion phasing (for example, LPP or CA 50 ) as closed loop feedback signal.
[0077] 4. Compare CA 50 from each cylinder to target CA 50 value from lookup table.
[0078] 5. If cylinders are randomly dispersed around target CA 50 , then use secondary control parameters (for example, injection timing/quantity during recompression, spark timing, etc.) to trim cylinders.
[0079] 6. If ALL of the cylinders are displaced from target value then this indicates a shift in fuel “octane index”.
[0080] 7. Use either NVO or secondary control parameters (for example, injection timing/quantity during recompression, spark timing, etc.) to adjust engine average CA 50 and update tables based on change in required NVO using relationship (4).
[0081] With reference to FIG. 14 , a more specific exemplary control schematic is illustrated. Engine 10 includes fuel injectors 41 and valve actuation apparatus 25 . An open-loop portion of the control including Valve Control Baseline Set-point Map 101 is preferably calibrated offline through known dynamometric techniques. This open-loop control may comprise, for example, tabulated intake and exhaust valve positions as stored in calibration tables referenced by engine speed and load data. It is these nominal valve positions that are used to establish baseline negative valve overlap NVO 102 . In accordance with an embodiment, engine 10 is additionally configured with one or more cylinder pressure sensors 103 . The control system is structured including a closed-loop portion to adjust the nominal valve positions based on combustion information 105 derived from cylinder pressure sensors 103 . NVO correction uses combustion phasing feedback information 105 (e.g. % burned angle, heat release rate, combustion duration, maximum rate of pressure rise, just to name a few) and compares it to a combustion phasing target 107 , e.g. from Baseline Combustion Phasing Map 109 . This comparison perturbs the nominal valve positions from Valve Control Baseline Set-point Map 101 to drive the combustion phasing error 106 input to Valve Control Set-point Optimizer 111 to zero. Limiter 113 limits the authority over valve adjustments in accordance with the particular hardware limitations of the engine including the valve actuation apparatus 25 . Hence, the control establishes negative valve overlap through intake and exhaust valve actuations that effect minimal error in predefined combustion phasings up to the limitations of the valve actuation apparatus.
[0082] Valve position targets and combustion phasing targets are referenced, for example, using engine speed and load data. Additional correction may be afforded in accordance with intake temperature, ambient pressure, fuel type, etc. Baseline Combustion Phasing Map 109 is preferably calibrated offline through known dynamometric techniques. Baseline combustion phasing targets represent desired combustion characteristics relative to a plurality of metrics (e.g. NO x emissions, combustion noise, fuel economy, and maximum MBT at dilution/knock limits for gasoline applications). The closed loop portion of the control maintains the desired combustion characteristics in the presence of variations and disturbances including variations in the fuel being provided to the engine. The Valve Control Set-point Optimizer 111 in one implementation is a slow integrator. In other words, the Valve Control Set-point Optimizer 111 slowly increases or decreases the valve set-points if the achieved NVO (combustion phasing feedback) 105 is less or more than expected.
[0083] Exemplary information 105 may correspond substantially to 50% fuel burned, e.g. crank angle of 50% fuel burned (CA 50 ). Information 105 may correspond, for example, to an average across all cylinders, to a single cylinder, or to a bank of cylinders in accordance with the available engine cylinder pressure sensing hardware configuration and cost considerations. And, with respect to valve actuation hardware which is limited in its individual cylinder-to-cylinder adjustment capability (i.e. cam phasers), the NVO is necessarily established consistently for each of the individual cylinders. For this reason, other cylinder-to-cylinder combustion variability factors may result in cylinder-to-cylinder variability in the combustion phasings. Generally, therefore, it is with respect to a single NVO setting applicable to all cylinders that the average combustion phasing across all cylinders results in a minimal average deviation from the desired phasing. Independently actuatable valves (i.e. fully flexible valve actuation) may allow for individual cylinder-to-cylinder adjustments of NVO in accordance with respective cylinder pressure sensing. Still, deviation of the average combustion phasing across all cylinders from desired combustion phasing is minimized. As mentioned earlier, all of this is accomplished within the boundaries of the valve actuation apparatus authority.
[0084] At the limits of valve actuation apparatus authority, a secondary combustion phasing control more particularly adaptable to individual cylinder-to-cylinder variations is preferably implemented. For example, fuel injection timing in a direct injection fuel apparatus may be controlled on a cylinder to cylinder basis. In FIG. 14 , another open-loop portion of the control including Fuel Injection Control Baseline Set-point Map 115 is preferably calibrated offline through known dynamometric techniques. This open-loop control may comprise, for example, tabulated fuel injection timing as stored in calibration tables referenced by engine speed and load data. It is these nominal fuel injection timings that are used to establish baseline fuel injection timings 117 . In accordance with the secondary combustion phasing control, and preferably in accordance with limits in the valve actuation authority of the valve position control as illustrated (or alternatively in accordance with minimal combustion phasing having been satisfied by the valve control), a closed-loop control portion adjusts the timings or the mass of reforming fuel based on combustion information 105 derived from cylinder pressure sensors 103 . Fuel injection timing correction uses combustion phasing feedback information 105 and compares it to the combustion phasing target 107 . This comparison perturbs the nominal fuel injection timings from Fuel Injection Control Baseline Set-point Map 115 to drive the error input to Fuel Injection Control Set-point Optimizer 119 to zero. Hence, the secondary combustion phasing control establishes fuel injection timing that further trims the combustion phasing error 106 . An alternative secondary combustion phasing control may be implemented in similar fashion utilizing spark timing controls at least in operating regions wherein spark assist is utilized and normal spark authority ranges can effect the desired combustion phasing shifts. Combustion phasing of all cylinders may be adjusted, for example via a shift of all injection timings, or each individual cylinder's combustion phasing may be adjusted, for example via cylinder-to-cylinder fuel injection optimizations. The latter implementation may benefit from the utilization of individual or per-cylinder combustion sensing.
[0085] NVO has been shown an effective parameter for HCCI engine combustion phasing control from 7 mg/cycle to 15 mg/cycle to account for fuel variations. Below 7 mg/cycle, the NVO is preferably changed for combustion stability and emissions considerations and the combustion phasing is controlled primarily by recompression injected fuel mass and timing. Octane index (OI) correlations ( FIGS. 11 and 12 ) can be used to predict how commercially available, fully-blended gasoline fuels will behave under HCCI operation within a wide load range. In particular, with known RON and MON, OI can be calculated using K=2. The CA 50 can then be calculated using the relationship (3) herein above. The NVO requirement to move CA 50 back to its optimal location (substantially about 4 degrees aTDC) is calculated using the relationship (4) herein above.
[0086] The present invention has been described with respect to certain preferred embodiments and variations herein. Other alternative embodiments, variations ad implementations may be implemented and practiced without departing from the scope of the invention which is to be limited only by the claims as follow:
|
Operation of a homogeneous charge compression ignition engine is adapted to fuel variations. A variable valve actuating system is employed to effect conditions conducive to homogeneous charge compression ignition operation. Nominal valve timing is selected and adjustments thereto are made based on deviations in combustion phasing from a desired combustion phasing. Fuel delivery timing and quantity are adjusted once valve timing authority limits are reached to achieve further combustion phasing improvement.
| 5
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.